Multi-stage vapor ablation treatment method and vapor generation and delivery system

Abstract

Ablation catheters and systems include a flexible catheter tip with a distal needle or port for delivering an ablative agent to target tissue. Pressure monitoring during the ablation procedure ensures that the procedure is performed within a safe range and achieves the intended effect. Positioning elements help to keep the device in the proper position relative to the target tissue and also prevent the ablative agent from entering normal tissue.

Description

[0001] Cross-References

[0002] This application relies on U.S. Provisional Patent Application No. 62 / 679,694, filed June 1, 2018, entitled "Ablation Systems and Methods," the entire contents of which are incorporated herein by reference.

[0003] This application is related to U.S. Patent Application No. 15 / 600,670, filed May 19, 2017, entitled "Ablation Catheter with Integrated Cooling," which relies on U.S. Provisional Patent Application No. 62 / 425,144, filed November 22, 2016, entitled "Methods and Systems for Ablation," and U.S. Provisional Patent Application No. 62 / 338,871, filed May 19, 2016, entitled "Cooled Coaxial Ablation Catheter," as priority.

[0004] This application is also related to U.S. Patent Application 15 / 144,768, filed May 2, 2016, entitled "Induction-Based Micro-Volume Heating System," which is a continuation-in-part of U.S. Patent Application 14 / 594,444, filed January 12, 2015, entitled "Method and Apparatus for Tissue Ablation," and issued as U.S. Patent No. 9,561,068 on February 7, 2017, which relies on U.S. Patent Application No. 14 / 158,687, filed January 17, 2013, entitled "Method and Apparatus for Tissue Ablation," and issued as U.S. Patent No. 9,561,067 on February 7, 2017, which in turn relies on U.S. Provisional Patent Application No. 61 / 753,831, filed January 17, 2013, entitled "Method and Apparatus for Tissue Ablation," as priority.

[0005] U.S. Patent Application No. 14 / 158,687 is also a continuation-in-part of U.S. Patent Application No. 13 / 486,980, filed June 1, 2012, entitled "Method and Apparatus for Tissue Ablation," and issued as U.S. Patent No. 9,561,066 on February 7, 2017, which in turn relies on U.S. Provisional Patent Application No. 61 / 493,344, filed June 3, 2011, entitled "Method and Apparatus for Tissue Ablation," as priority.

[0006] U.S. Patent Application No. 13 / 486,980 is also a continuation-in-part of U.S. Patent Application No. 12 / 573,939, filed October 6, 2009, entitled "Method and Apparatus for Tissue Ablation," which in turn relies on U.S. Provisional Patent Application No. 61 / 102,885, filed October 6, 2008, of the same title as priority.

[0007] All of the above-cited applications are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0008] The present specification relates to systems and methods configured to generate and deliver steam for ablation therapy. More particularly, the present specification relates to systems and methods including flexible catheter positioning elements and / or tips having needles or ports for performing ablation therapy to specific organ systems. BACKGROUND

[0009] Ablation, as it relates to the present specification, involves the removal or destruction of bodily tissue by the introduction of a destructive agent such as RF energy, laser energy, ultrasound energy, coolant, or steam. Ablation is commonly used to eliminate lesions or unwanted tissue such as, but not limited to, cysts, polyps, tumors, hemorrhoids, and other similar lesions.

[0010] Steam-based ablation systems, such as U.S. Patent Nos. 9,615,875, 9,433,457, 9,376,497, 9,561,068, 9,561,067, and 9,561,066 disclose ablation systems that controllably deliver steam to a tissue target through one or more lumens. One problem with all such steam-based ablation systems is the potential overheating or burning of healthy tissue. Steam passing through a channel within a body lumen can heat the surface of the channel and potentially cause the outer surface of the medical tool to become overheated beyond the operating tip end of the tool itself. As a result, a physician can inadvertently burn healthy tissue when the outer portion of the device other than the distal operating end of the tool accidentally contacts healthy tissue. U.S. Patent Nos. 9,561,068, 9,561,067, and 9,561,066 are hereby incorporated by reference.

[0011] Furthermore, the effective use of steam generally requires controllably exposing a certain amount of tissue to the steam. However, prior art steam ablation methods either fail to sufficiently enclose the space to be treated, thereby failing to adequately expose the tissue, or overly enclose the space to be treated, thereby dangerously increasing the pressure and / or temperature within the patient's organs. Pressure sensors located on the catheter can help regulate energy delivery, but they are not necessarily reliable and are a potential point of failure for the system.

[0012] Accordingly, it would be desirable to provide a steam-based ablation device that integrates safety mechanisms into the device itself to prevent unwanted burning during use. It would also be desirable to provide a method to better control the amount of steam exposed to the target tissue. It would also be desirable to be able to control the pressure level within the enclosed space without relying on a pressure sensor in the catheter itself. Finally, it would be desirable to provide steam-based ablation systems and methods for treating various conditions, including precancerous or cancerous tissue in the esophagus, duodenum, bile duct, and pancreas. SUMMARY

[0013] The present specification discloses

[0014] A multi-stage method of treating at least one of overweight, obesity, eating disorders, metabolic syndrome, dyslipidemia, diabetes, polycystic ovary disease, fatty liver disease, non-alcoholic fatty liver disease, or non-alcoholic steatohepatitis disease by ablating duodenal tissue using a vapor ablation system, wherein the vapor ablation system comprises a controller having at least one processor in data communication with at least one pump and a catheter connection port in fluid communication with the at least one pump, the multi-stage method comprising: connecting a proximal end of a first catheter to the catheter connection port to place the first catheter in fluid communication with the at least one pump, wherein the first catheter comprises at least two positioning elements spaced apart along a length of the catheter and at least two ports between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein, in the first configuration, each of the at least two positioning elements is compressed within the catheter and, in the second configuration, each of the at least two positioning elements is expanded to be at least partially outside of the catheter; positioning the first catheter within a patient such that, when expanded into the second configuration, a distal positioning element of the at least two positioning elements is positioned within the patient's small intestine and a proximal positioning element of the at least two positioning elements is positioned more than 1 cm from the distal positioning element of the at least two positioning elements; expanding each of the at least two positioning elements into their second configuration; activating the controller, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into at least one lumen of the first catheter and, wherein, upon activation, the controller is configured to cause delivery of electrical current to at least one electrode located within the at least one lumen of the first catheter; delivering vapor through the ports in the first catheter between the at least two positioning elements; using the controller, cutting off delivery of saline and electrical current; removing the first catheter from the patient to complete a first treatment stage; waiting at least six weeks; determining efficacy of the first treatment stage; connecting a proximal end of a second catheter to the catheter connection port to place the second catheter in fluid communication with the at least one pump in accordance with the determined efficacy, wherein the second catheter comprises at least two positioning elements spaced apart along a length of the catheter and at least two ports between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein, in the first configuration, each of the at least two positioning elements is compressed within the catheter and, in the second configuration, each of the at least two positioning elements is expanded to be at least partially outside of the catheter; positioning the second catheter within the patient such that, when expanded into the second configuration, a distal positioning element of the at least two positioning elements is positioned within the patient's small intestine and a proximal positioning element of the at least two positioning elements is positioned less than 1 cm from the distal positioning element of the at least two positioning elements; deploying each of the at least two positioning elements into their second configuration;activating the controller, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into the at least one lumen of the first catheter, and wherein, upon activation, the controller is configured to cause delivery of electrical current to the at least one electrode positioned within the at least one lumen of the first catheter; delivering steam through a port in the second catheter positioned between the at least two positioning elements; using the controller, cutting off delivery of saline and electrical current; and removing the second catheter from the patient to complete the second treatment phase.

[0015] Optionally, delivery of saline and electrical current is automatically cut off after no more than 60 seconds during the first treatment phase and the second treatment phase.

[0016] Optionally, the method further comprises, during the first treatment phase and the second treatment phase, repeatedly activating the controller to deliver saline into the lumen and to deliver electrical current to the at least one electrode using at least one of a foot pedal in data communication with the controller, a switch on the catheter, or a switch on the controller.

[0017] Optionally, during the first treatment phase and the second treatment phase, steam is delivered such that energy in the range of 5 calories per second to 2500 calories per second is delivered.

[0018] Optionally, during the first treatment phase and the second treatment phase, steam is delivered such that energy in the range of 5 calories per gram of tissue to be ablated to 40 calories per gram of tissue to be ablated is delivered.

[0019] Optionally, during the first treatment phase and the second treatment phase, steam is delivered such that at least fifty percent of the circumference of the small intestine is ablated.

[0020] Optionally, during the first treatment phase, the at least two positioning elements define an enclosed space with the small intestine, and wherein at least one of the at least two positioning elements is positioned relative to the small intestine to allow air to flow out of the enclosed space when steam is delivered.

[0021] Optionally, during the second treatment phase, the at least two positioning elements define an enclosed space with the small intestine, and wherein at least one of the at least two positioning elements is positioned relative to the small intestine to allow air to flow out of the enclosed space when steam is delivered.

[0022] Optionally, in the first treatment phase and the second treatment phase, the therapeutic effect is determined by at least one of: a reduction in the patient's total body weight of at least 1% relative to the patient's total body weight prior to ablation; a reduction in the patient's excess body weight of at least 1% relative to the patient's excess body weight prior to ablation; a reduction in the patient's total body weight of at least 1% relative to the patient's total body weight prior to ablation and a reduction in the patient's health level of no more than 5% relative to the patient's health level prior to ablation; a reduction in the patient's excess body weight of at least 1% relative to the patient's excess body weight prior to ablation and a reduction in the patient's health level of no more than 5% relative to the patient's health level prior to ablation; a reduction in the patient's pre-meal ghrelin level of at least 1% relative to the patient's pre-meal ghrelin level prior to ablation; a reduction in the patient's post-meal ghrelin level of at least 1% relative to the patient's post-meal ghrelin level prior to ablation; an increase in the patient's exercise output of at least 1% relative to the patient's exercise output prior to ablation; an increase in the patient's glucagon-like peptide-1 level of at least 1% relative to the patient's glucagon-like peptide-1 level prior to ablation; an increase in the patient's leptin level of at least 1% relative to the patient's leptin level prior to ablation; a reduction in the patient's appetite over a predetermined period of time relative to the patient's appetite prior to ablation; an increase in the patient's peptide YY level of at least 1% relative to the patient's peptide YY level prior to ablation; a reduction in the patient's lipopolysaccharide level of at least 1% relative to the patient's lipopolysaccharide level prior to ablation; a reduction in the patient's motilin-related peptide level of at least 1% relative to the patient's motilin-related peptide level prior to ablation; an increase in the patient's cholecystokinin level of at least 1% relative to the patient's cholecystokinin level prior to ablation; an increase in the patient's resting metabolic rate of at least 1% relative to the patient's resting metabolic rate prior to ablation; an increase in the patient's plasma beta-endorphin level of at least 1% relative to the patient's plasma beta-endorphin level prior to ablation; a reduction in the patient's HbAlc level of at least 0.3% relative to the patient's HbAlc level prior to ablation; a reduction in the patient's triglyceride level of at least 1% relative to the patient's triglyceride level prior to ablation; a reduction in the patient's total blood cholesterol level of at least 1% relative to the patient's total blood cholesterol level prior to ablation; a reduction in the patient's blood glucose level of at least 1% relative to the patient's blood glucose level prior to ablation; a modulation of the composition of the human's gut microbiota from a first state prior to ablation to a second state after ablation, wherein the first state has a first level of Bacteroidetes and a first level of Firmicutes, wherein the second state has a second level of Bacteroidetes and a second level of Firmicutes, wherein the second level of Bacteroidetes is at least 3% greater than the first level of Bacteroidetes, and wherein the second level of Firmicutes is at least 3% less than the first level of Firmicutes; or a reduction in the patient's cumulative daily dose of anti-diabetic medication of at least 10% relative to the patient's cumulative daily dose of anti-diabetic medication prior to ablation.

[0023] Optionally, in the first treatment phase and the second treatment phase, the therapeutic efficacy is determined by at least one of: an improvement in the patient's lipid profile by at least 10% relative to the patient's lipid profile prior to ablation, wherein the lipid profile is defined by at least the ratio of LDL cholesterol to HDL cholesterol, and the improvement is defined as a decrease in the ratio of LDL cholesterol to HDL cholesterol; a decrease in the patient's LDL cholesterol level by at least 10% relative to the patient's LDL cholesterol level prior to ablation; or, a decrease in the patient's VLDL cholesterol level by at least 10% relative to the patient's VLDL cholesterol level prior to ablation.

[0024] Optionally, in the first treatment phase and the second treatment phase, the therapeutic efficacy is determined by at least one of: a 10% decrease in ALT or AST levels relative to the patient's ALT or AST levels prior to ablation; an absolute serum ferritin level below 1.5 ULN (upper limit of normal) relative to the patient's serum ferritin level prior to ablation; a liver steatosis (HS) of less than 5% as measured by liver biopsy relative to the patient's HS level prior to ablation; a liver steatosis (HS) of less than 5% as measured by magnetic resonance (MR) imaging, or by spectroscopy, or by proton density fat fraction; an improvement in the NAFLD fibrosis score (NFS) by at least 5% relative to the patient's NFS prior to ablation; an improvement in the NAFLD activity score by at least 5% relative to the patient's NAS prior to ablation; an improvement in the steatosis activity fibrosis (SAF) score by at least 5% relative to the patient's SAF fibrosis score prior to ablation; a decrease in the average annual fibrosis progression rate by at least 5% relative to the patient's average annual fibrosis progression rate prior to ablation, as measured by histology, the Fibrosis-4 (FIB-4) index, the aspartate aminotransferase-to-platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) panel, FibroTest, Fibrosure, or Hepascore), or imaging (transient elastography (TE), MR elastography (MRE), acoustic radiation force impulse imaging, or ultrasound shear wave elastography); a decrease in the circulating levels of cytokeratin-18 fragments by at least 5% relative to the patient's circulating levels of cytokeratin-18 fragments prior to ablation; a decrease in liver stiffness by at least 5% relative to the patient's liver stiffness prior to ablation, as measured by vibration-controlled transient elastography (VCTE / FibroScan); an improvement in the NAS by at least 2 points, an improvement in hepatocellular ballooning by at least 1 point, an improvement in lobular inflammation or steatosis score by at least 1 point, and no increase in fibrosis score relative to the patient's NAS, hepatocellular ballooning, lobular inflammation, steatosis, and fibrosis scores prior to ablation; an improvement in the NFS score by at least 5% relative to the patient's NFS score prior to ablation; or, at least a 5% improvement in any of the above NAFLD parameters relative to a sham intervention or placebo.

[0025] The present specification also discloses a multi-stage method of treating cancerous or precancerous esophageal tissue by ablating the cancerous or precancerous esophageal tissue using a vapor ablation system, wherein the vapor ablation system comprises a controller having at least one processor in data communication with at least one pump and a catheter connection port in fluid communication with the at least one pump, the multi-stage method comprising: connecting a proximal end of a first catheter to the catheter connection port to place the first catheter in fluid communication with the at least one pump, wherein the first catheter comprises at least two positioning elements spaced apart along a length of the catheter and at least two ports between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein, in the first configuration, each of the at least two positioning elements is compressed within the catheter and, in the second configuration, each of the at least two positioning elements is expanded to be at least partially outside of the catheter; positioning the first catheter within a patient such that, when expanded into the second configuration, a distal positioning element of the at least two positioning elements is positioned within the patient’s small intestine and a proximal positioning element of the at least two positioning elements is positioned more than 1 cm from the distal positioning element of the at least two positioning elements; expanding each of the at least two positioning elements into their second configuration; activating the controller, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into at least one lumen of the first catheter, and wherein, upon activation, the controller is configured to cause an electrical current to be delivered to at least one electrode located within the at least one lumen of the first catheter; delivering vapor through the ports in the first catheter between the at least two positioning elements; using the controller, cutting off delivery of the saline and the electrical current; removing the first catheter from the patient to complete a first treatment stage; waiting at least six weeks; determining an efficacy of the first treatment stage; connecting a proximal end of a second catheter to the catheter connection port to place the second catheter in fluid communication with the at least one pump in accordance with the efficacy determination, wherein the second catheter comprises a distal tip having at least one port and at least one positioning element attached to the distal tip such that, when in an operational configuration, the at least one positioning element surrounds the at least one port and is configured to direct all vapor expelled from the at least one port; positioning the second catheter within the patient such that a distal surface of the at least one positioning element is positioned near the patient’s esophagus; activating the controller, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into at least one lumen of the second catheter, and wherein, upon activation, the controller is configured to cause an electrical current to be delivered to at least one electrode located within the at least one lumen of the second catheter; delivering vapor through the at least one port at the distal end of the second catheter; using the controller, cutting off delivery of the saline and the electrical current; and removing the second catheter from the patient to complete a second treatment stage.

[0026] Optionally, the delivery of saline and electrical current is automatically cut off for no more than 60 seconds during the first treatment phase and the second treatment phase.

[0027] Optionally, the method further comprises, during the first treatment phase and the second treatment phase, repeatedly activating the controller to deliver saline into the lumen and to deliver electrical current to the at least one electrode using at least one of a foot pedal, a switch on the catheter, or a switch on the controller in data communication with the controller.

[0028] Optionally, the delivery of steam is such that energy in the range of 5 calories per second to 2500 calories per second is delivered during the first treatment phase and the second treatment phase.

[0029] Optionally, the delivery of steam is such that energy in the range of 5 calories per gram of tissue to be ablated to 40 calories per gram of tissue to be ablated is delivered during the first treatment phase and the second treatment phase.

[0030] Optionally, the delivery of steam is such that at least fifty percent of the circumference of the small intestine is ablated during the first treatment phase and the second treatment phase.

[0031] Optionally, the at least two positioning elements define an enclosed space with the esophageal tissue during the first treatment phase, and wherein at least one of the at least two positioning elements is positioned relative to the esophageal tissue to allow air to flow out of the enclosed space when steam is delivered.

[0032] Optionally, the at least one positioning element defines an enclosed space with the esophageal tissue during the second treatment phase, and wherein the at least one positioning element is positioned relative to the esophageal tissue to allow air to flow out of the enclosed space when steam is delivered.

[0033] The present specification also discloses a flexible heating chamber configured to be incorporated into a distal end of a catheter, the flexible heating chamber comprising: an outer shell; an inner core coaxial with the outer shell; a first electrode array disposed between the outer shell and the inner core, wherein the first electrode array comprises a first metal ring having a plurality of first fins; and a second electrode array disposed between the outer shell and the inner core, wherein the second electrode array comprises a second metal ring having a plurality of second fins, and wherein the first and second fins intersect each other such that a segmented gap separates each of the first and second fins.

[0034] Optionally, the plurality of first and second fins extend radially into a space between the outer shell and the inner core, and wherein the plurality of first and second fins also extend along a longitudinal axis of the heating chamber.

[0035] Optionally, each of the plurality of first and second fins has a first dimension along a radius of the heating chamber and a second dimension along a longitudinal axis of the heating chamber.

[0036] Optionally, water or saline flows through the segmented spacing, and an electrical current is provided to the first and second electrode arrays, causing the first and second fins to generate heat and vaporize the water or saline into steam.

[0037] Optionally, the heating chamber has a width of 1 to 5 mm and a length of 5 to 50 mm.

[0038] Optionally, the first electrode array has 1 to 50 fins, and the second electrode array has 1 to 50 fins.

[0039] Optionally, the segmented spacing ranges from 0.01 to 2 mm.

[0040] The present specification also discloses a catheter for performing ablation of target tissue, the catheter having a body with a proximal end, a distal end, a first lumen, and a second lumen, the catheter comprising: a proximal balloon and a distal balloon located near the distal end of the body; a plurality of ports on the body between the proximal and distal balloons; and a first flexible heating chamber incorporated into the second lumen and positioned proximate to the proximal balloon, the first flexible heating chamber comprising: an outer jacket; an inner core coaxial with the outer jacket; a first electrode array disposed between the outer jacket and the inner core, wherein the first electrode array comprises a first metallic ring having a plurality of first fins; and a second electrode array disposed between the outer jacket and the inner core, wherein the second electrode array comprises a second metallic ring having a plurality of second fins, and wherein the first and second fins interdigitate such that a first segmented spacing separates each of the first and second fins.

[0041] Optionally, a first pump coupled to the proximal end of the body pushes air through the first lumen to inflate the proximal and distal balloons; a second pump coupled to the proximal end of the body pushes water or saline through the second lumen to supply the water or saline to the proximal end of the first heating chamber; an RF generator coupled to the proximal end of the body provides an electrical current to the first and second electrode arrays, causing the first and second fins to generate heat and vaporize the water or saline into steam for delivery to the target tissue through the ports.

[0042] Optionally, the plurality of first and second fins extend radially into a space between the outer jacket and the inner core of the first heating chamber, and wherein the plurality of first and second fins also extend along a longitudinal axis of the first heating chamber.

[0043] Optionally, each of the plurality of first and second fins has a first dimension along a radius of the first heating chamber and a second dimension along a longitudinal axis of the first heating chamber.

[0044] Optionally, the conduit further comprises a second flexible heating chamber arranged in series with the first flexible heating chamber, wherein the second flexible heating chamber comprises: an outer shell; an inner core coaxial with the outer shell; a third electrode array disposed between the outer shell and the inner core, wherein the third electrode array comprises a third metallic ring having a plurality of third fins; and a fourth electrode array disposed between the outer shell and the inner core, wherein the fourth electrode array comprises a fourth metallic ring having a plurality of fourth fins, and wherein the third and fourth fins intersect each other such that a second segmental spacing separates each of the third and fourth fins.

[0045] Optionally, the plurality of third and fourth fins extend radially into a space between the outer shell and the inner core of the second heating chamber, and the plurality of third and fourth fins also extend along a longitudinal axis of the second heating chamber.

[0046] Optionally, each of the plurality of third and fourth fins has a first dimension along a radius of the second heating chamber and a second dimension along a longitudinal axis of the second heating chamber.

[0047] Optionally, each of the first and second heating chambers has a width of 1 to 5 mm and a length of 5 to 50 mm.

[0048] Optionally, the first and third electrode arrays have 1 to 50 fins, and the second and fourth electrode arrays have 1 to 50 fins.

[0049] Optionally, the first and second segmental spacings are 0.01 to 2 mm.

[0050] The specification also discloses a method of performing ablation of Barrett's esophageal tissue, comprising: inserting a catheter into a patient's esophagus, the catheter having a body with a proximal end, a distal end, a first lumen, and a second lumen, wherein the catheter comprises: a proximal balloon and a distal balloon located near the distal end of the body; a plurality of ports on the body between the proximal and distal balloons; and at least one flexible heating chamber incorporated into the second lumen and positioned proximal to the proximal balloon, the at least one flexible heating chamber comprising: an outer jacket; an inner core coaxial with the outer jacket; a first electrode array disposed between the outer jacket and the inner core, wherein the first electrode array comprises a first metal ring having a plurality of first fins; and a second electrode array disposed between the outer jacket and the inner core, wherein the second electrode array comprises a second metal ring having a plurality of second fins, and wherein the first and second fins interdigitate such that a first subsection spacing separates each of the first and second fins; positioning the distal balloon distal to a portion of a Barrett's esophagus and the proximal balloon proximal to the portion of the Barrett's esophagus such that the ports are positioned in the portion of the Barrett's esophagus; inflating the proximal and distal balloons to position the catheter in the esophagus; providing water or saline to the catheter; and providing electrical current to the first and second electrode arrays such that the first and second fins generate heat and vaporize the water or saline into steam, wherein the steam is delivered through the ports to ablate Barrett's esophageal tissue.

[0051] Optionally, a first pump coupled to the proximal end of the body pushes air through the first lumen to inflate the proximal and distal balloons; a second pump coupled to the proximal end of the body pushes water or saline through the second lumen to supply the water or saline to the proximal end of the heating chamber; an RF generator coupled to the proximal end of the body supplies electrical current to the first and second electrode arrays.

[0052] Optionally, each of the plurality of first and second fins has a first dimension along a radius of the heating chamber and a second dimension along a longitudinal axis of the heating chamber.

[0053] The present specification also discloses a method of ablating pancreatic tissue, comprising: providing an ablation device comprising: an echoendoscope; a catheter having a needle at a distal end and configured to pass within a channel of the echoendoscope to deliver steam to the pancreatic tissue; a controller programmed to determine an amount of thermal energy required to ablate the pancreatic tissue, programmed to limit a maximum dose of the ablation agent based on a type of disease being treated, and programmed to limit the amount of thermal energy delivered such that a pressure within a patient's pancreas does not exceed 5 atm; advancing the echoendoscope into a patient's gastrointestinal tract and proximate to the pancreatic tissue; using the echoendoscope to locate the pancreatic tissue; advancing the catheter through the channel of the echoendoscope such that the needle penetrates a gastrointestinal wall at a penetration site and into the pancreatic tissue; and delivering steam through the needle into the pancreatic tissue for ablation.

[0054] Optionally, the method further comprises the step of: measuring at least one dimension of the pancreatic tissue using the echoendoscope; and the controller uses the at least one measured dimension to calculate an amount of steam to be delivered.

[0055] Optionally, the method further comprises applying suction to the needle prior to delivering steam to aspirate fluid and / or cells from the prostate tissue.

[0056] Optionally, the needle comprises an outer sheath, and the method further comprises circulating water through the outer sheath while steam is delivered to cool the penetration site.

[0057] Optionally, the method further comprises using the echoendoscope to observe the pancreatic tissue while the ablation is being performed, and stopping the ablation once sufficient ablation has been achieved according to visual observation.

[0058] Optionally, the ablation terminates after the pressure measured in the pancreas remains in the range of 0.1 to 5 atmospheres for at least 1 second. Optionally, the method further comprises delivering steam again after the ablation has terminated for a period of at least 1 second.

[0059] Optionally, the ablation stops when the pressure measured in the ablation device exceeds 5 atmospheres.

[0060] Optionally, the temperature of the pancreatic tissue is 100°C to 110°C for at least a portion of the ablation process.

[0061] Optionally, the ablation device further comprises a pressure sensor.

[0062] Optionally, the ablation device further comprises a temperature sensor.

[0063] The present specification also discloses a method of ablating pancreatic tissue, comprising the steps of: providing an ablation device comprising: a catheter having a hollow shaft and a retractable needle through which an ablation agent can travel; at least one infusion port on the needle for delivering the ablation agent to the upper gastrointestinal tissue; at least one sensor for measuring at least one parameter of the catheter; and a controller comprising a microprocessor for controlling the ablation agent delivery; inserting an echoendoscope into the upper gastrointestinal tract of a patient; identifying pancreatic tissue to be ablated using the echoendoscope; passing the catheter through the echoendoscope such that the at least one distal positioning element is positioned proximal to the pancreatic tissue to be ablated in the gastrointestinal tract; extending the needle through the catheter in the upper gastrointestinal lumen of the patient such that the infusion port is located within the pancreatic tissue of the patient; operating the at least one sensor to measure at least one parameter of the catheter; using the at least one parameter measurement to control the flow of ablation agent delivered to the pancreatic tissue; and delivering the ablation agent through the at least one infusion port to ablate the pancreatic tissue.

[0064] The present specification also discloses a device for thermal fluid ablation for use with an endoscope, comprising: an elongated tubular member having a length and a lumen for delivering a thermal fluid from a proximal end to a distal end, the distal end being open and adapted to eject steam at a target tissue at a temperature and at a low pressure; and an insulating element covering at least a portion of the device; wherein an outer diameter of the device is configured to allow the device to pass through the endoscope.

[0065] Optionally, the thermal fluid is steam. Optionally, the temperature ranges from 65°C to 150°C. Optionally, the pressure is less than 5 atmospheres. Optionally, the insulating element is a heat resistant polymer.

[0066] The present specification also discloses a catheter for use in an ablation procedure, comprising: a tubular member having an inner surface defining a passageway for flow of an ablation fluid, a proximal end for receiving the ablation fluid from a source, and a distal end adapted to eject a low pressure ablation agent at a target tissue; and an insulating element disposed longitudinally along at least a portion of the length of the tubular member.

[0067] The present specification also discloses a catheter for use with an endoscope in a thermal ablation procedure, the catheter comprising: a tubular member having a proximal end for receiving an ablation agent, an open distal end adapted to eject a low pressure ablation agent at a target tissue, an inner surface comprising a heat resistant polymer defining a passageway and configured to contact the ablation agent flowing from the proximal end to the distal end; and a cooling element disposed longitudinally along at least a portion of the outer surface.

[0068] The present specification also discloses a vapour ablation device for vapour-jet ablation, comprising: a scope; a catheter having a distal end, wherein the catheter is disposed within the scope; and a vapour source attached to the catheter by a conduit, wherein the device is configured such that, in use, high temperature, low pressure vapour exits the catheter distal end, and wherein the distal end of the catheter is adapted to jet the vapour in a radial direction substantially perpendicular to the catheter axis.

[0069] The present specification also discloses a vapour-jet device for vapour-jet ablation, comprising: a scope having a distal end provided with a lens such that the scope is used to locate target tissue; a catheter having a distal end, the catheter being connected to and carried by the scope; a vapour source connected to the catheter by a conduit and disposed outside the patient; wherein the device is configured such that, in use, high temperature, low pressure vapour exits the catheter distal end.

[0070] The present specification also discloses a method of ablating a hollow tissue or organ, comprising the steps of: replacing the natural contents of the hollow tissue or organ with an electrically conductive medium; and delivering an ablation agent to the electrically conductive medium to ablate the tissue or organ.

[0071] The present specification also discloses an ablation device comprising a port for delivering an electrically conductive medium and a source of an ablation agent.

[0072] Optionally, the ablation comprises one of cryoablation or thermal ablation.

[0073] Optionally, the device comprises a port for removing contents of the hollow organ or electrically conductive medium.

[0074] The present specification also discloses a method of ablating a blood vessel, comprising the steps of: replacing blood in the target blood vessel with an electrically conductive medium; and delivering an ablation agent to the electrically conductive medium to ablate the desired blood vessel.

[0075] Optionally, the method further comprises stopping blood flow into the target blood vessel. Optionally, the blood flow is occluded by applying a tourniquet. Optionally, the blood flow is occluded by applying an endoluminal occlusion element. Optionally, the endoluminal occlusion element comprises a one-way valve.

[0076] Optionally, a sensor is used to control the flow of the ablation agent.

[0077] Optionally, the electrically conductive medium is one of water or saline.

[0078] The present specification also discloses a device for ablating a blood vessel, the device comprising a catheter having a proximal end and a distal end, wherein the proximal end is operably connected to the distal end, a port at the distal end for infusing an electrically conductive medium to replace blood in the target blood vessel with the electrically conductive medium, and a source at the distal end for delivering an ablation agent to the electrically conductive medium.

[0079] Optionally, the device further comprises an occlusion element to restrict the flow of blood or conductive medium. Optionally, the occlusion element comprises a one-way valve. Optionally, the occlusion element is used to position the source of ablation agent in the blood vessel.

[0080] Optionally, the device further comprises an aspiration port for removing blood or conductive medium.

[0081] Optionally, the device further comprises a sensor to measure the delivery of ablation agent, blood flow, or an ablation parameter.

[0082] The present specification also discloses a method of ablating a blood vessel wall, comprising the steps of: placing a catheter in a segment of a blood vessel, blocking blood flow to the segment of the blood vessel, replacing a portion of the blood in the segment with a conductive medium, adding an ablation agent to the conductive medium, and conducting ablation energy through the conductive medium to the blood vessel wall to cause ablation of the blood vessel wall.

[0083] The present specification also discloses a device for ablating a blood vessel, comprising: a coaxial catheter having a proximal end and a distal end, an outer sheath, an inner tubular member; at least one port for injecting a conductive medium; a source for delivering an ablation agent; and at least one occlusion element configured to restrict blood flow and position the source of ablation agent in the blood vessel, wherein at least the outer sheath of the coaxial catheter is made of an insulating material.

[0084] The present specification also discloses a method of ablating a cyst, comprising the steps of: providing an ablation device comprising a catheter having a handle at a proximal end and a needle at a distal end; passing the catheter into a patient and advancing the catheter to the cyst; inserting the needle into the cyst; applying suction to the catheter to remove at least a portion of the contents of the cyst; injecting a conductive medium into the cyst through the needle; delivering an ablation agent into the conductive medium through the needle; and applying suction to the catheter to remove the conductive medium and the ablation agent.

[0085] The present specification also discloses a method of ablating a cyst, comprising the steps of: placing a catheter in a cyst, replacing a portion of the contents of the cyst with a conductive medium, adding an ablation agent to the conductive medium, and conducting ablation energy through the conductive medium to the cyst wall to cause ablation of the cyst.

[0086] The present specification also discloses a device for ablating a cyst, comprising: a coaxial catheter having a proximal end and a distal end, an outer sheath, an inner tubular member; at least one port for injecting a conductive medium; a source for delivering an ablation agent; and at least one port for removing cyst contents, wherein at least the outer sheath of the coaxial catheter is made of an insulating material.

[0087] Optionally, the device further comprises a sensor for controlling delivery of the ablation agent or for measuring the effect of the ablation.

[0088] Optionally, the catheter comprises an echogenic element to aid in placement of the catheter into the cyst under ultrasound guidance.

[0089] Optionally, the catheter comprises a radiopaque element to aid in placement of the catheter into the cyst under radiological guidance.

[0090] The present specification also discloses a method of ablating a solid tumor, comprising the steps of: placing a catheter in the tumor, instilling an electrically conductive medium into the tumor, adding an ablation agent to the electrically conductive medium, and conducting ablation energy through the electrically conductive medium to the tumor to cause ablation of the tumor.

[0091] The present specification also discloses a device for ablating a tumor, the device comprising an insulated catheter having a proximal end and a distal end, at least one port for infusing an electrically conductive medium, and a source for delivering an ablation agent.

[0092] Optionally, the device further comprises a sensor for controlling delivery of the ablation agent or for measuring the effect of the ablation.

[0093] Optionally, the catheter comprises an echogenic element to aid in placement of the catheter into the cyst under ultrasound guidance.

[0094] Optionally, the catheter comprises a radiopaque element to aid in placement of the catheter into the cyst under radiological guidance.

[0095] The present specification also discloses a method of ablating a tissue, the method comprising the steps of: providing an ablation device comprising: an insulated catheter having a hollow shaft and a retractable needle through which an ablation agent can travel; at least one infusion port on the needle for delivering the ablation agent to the tissue; and a controller comprising a microprocessor for controlling delivery of the ablation agent; passing the catheter and extending the needle through the at least one infusion port so that the needle and infusion port are located within the tissue of the patient; and delivering the ablation agent through the at least one infusion port to ablate the tissue.

[0096] Optionally, the ablation device further comprises at least one sensor for measuring at least one parameter of the tissue, and the method further comprises the steps of: operating the at least one sensor to measure at least one parameter of the tissue; and using the at least one parameter to determine an amount of ablation agent to deliver to the tissue.

[0097] Optionally, the ablation device further comprises at least one sensor for measuring at least one parameter of the catheter, and the method further comprises the steps of: operating the at least one sensor to measure at least one parameter of the catheter; and using the at least one parameter to shut off delivery of the ablation agent to the tissue.

[0098] Optionally, the at least one sensor comprises a temperature, pressure, infrared, electromagnetic, acoustic or RF energy emitter and sensor.

[0099] Optionally, the catheter comprises at least one distal positioning element configured such that, once the positioning element is deployed, the catheter is positioned in the vicinity of the tissue for ablation. Optionally, the at least one positioning element is any one of an inflatable balloon, a wire mesh disc, a conical attachment, an annular attachment or a free form attachment. Optionally, the positioning element is covered by an insulating material to prevent thermal energy from escaping to the tissue to be ablated.

[0100] Optionally, the at least one distal positioning element is separated from the tissue to be ablated by a distance greater than 0.1 mm.

[0101] Optionally, the delivery of the ablation agent is guided by predetermined program instructions.

[0102] Optionally, the ablation device further comprises at least one sensor for measuring a parameter of the tissue, and the method further comprises the steps of: operating the at least one sensor to measure a parameter of the tissue; and using the parameter measurement to control the flow of the ablation agent to the tissue.

[0103] Optionally, the sensor is any one of a temperature, pressure, light or chemical sensor.

[0104] Optionally, the ablation device further comprises a coaxial member configured to constrain the at least one positioning element, and the step of deploying the at least one distal positioning element further comprises removing the coaxial member from the ablation device.

[0105] Optionally, the catheter further comprises at least one suction port, and the method further comprises operating the at least one suction port to remove ablated tissue from the body.

[0106] Optionally, the ablation device further comprises an input device, and the method further comprises the step of an operator using the input device to control the delivery of the ablation agent.

[0107] Optionally, the tissue is a cyst.

[0108] The present specification also discloses a method of ablating tissue, comprising the steps of: providing an ablation device comprising: a catheter having a hollow shaft and a retractable needle through which an ablative agent can travel; at least one distal positioning element connected to a distal end of the catheter; at least one infusion port on the needle for delivering the ablative agent to the tissue, the at least one infusion port configured to deliver the ablative agent into a space defined by the distal positioning element; and a controller comprising a microprocessor for controlling delivery of the ablative agent; inserting the catheter such that the at least one positioning element is located in the vicinity of the tissue to be ablated; extending the needle through the catheter such that the infusion port is located in the vicinity of the tissue; and delivering the ablative agent through the at least one infusion port to ablate the tissue.

[0109] Optionally, the ablation device further comprises at least one input port on the catheter for receiving the ablative agent.

[0110] Optionally, the tissue is a pancreatic cyst.

[0111] The present specification also discloses a method of providing ablation therapy to a patient's gastrointestinal tract, comprising: inserting an ablation catheter into the gastrointestinal tract, wherein the ablation catheter comprises at least one positioning element and a port for delivering steam; forming a seal between an outer surface of the at least one positioning element and a wall of the gastrointestinal tract, forming an enclosed space in the gastrointestinal tract; delivering steam into the enclosed space through the ablation catheter; and causing the steam to condense on tissue within the gastrointestinal tract.

[0112] Optionally, the seal is dependent on temperature. Optionally, the seal is broken when the temperature within the enclosed space exceeds 90 degrees Celsius.

[0113] Optionally, the seal is dependent on pressure. Optionally, the seal is broken when the pressure within the enclosed space exceeds 5 atmospheres.

[0114] The present specification also discloses a method of providing ablation therapy to a patient's gastrointestinal tract, comprising: inserting an ablation catheter into the gastrointestinal tract; initiating a flow of saline through the ablation catheter, wherein the flow of saline is variable; heating the saline by delivering RF energy to the saline to produce steam; delivering the steam into the gastrointestinal tract through the ablation catheter; and causing the steam to condense on tissue within the gastrointestinal tract.

[0115] Optionally, the flow of saline during the thermal therapy is different than the flow of saline during a phase in which no thermal therapy is being performed.

[0116] Optionally, the flow of saline during the thermal therapy is higher than the flow of saline during a phase in which no thermal therapy is being performed.

[0117] Optionally, the flow of saline during the thermal therapy is lower than the flow of saline during a phase in which no thermal therapy is being performed.

[0118] This specification also discloses a method for ablating tissue, comprising: inserting a first ablation catheter into a patient's gastrointestinal tract, wherein the first ablation catheter includes a distal positioning element, a proximal positioning element, and a plurality of steam delivery ports between the distal and proximal positioning elements; dilating the distal positioning element; dilating the proximal positioning element to form a first seal between the periphery of the distal and proximal positioning elements and the gastrointestinal tract, and to form a first enclosed treatment space between the distal and proximal positioning elements and the surface of the patient's gastrointestinal tract; delivering steam through the delivery ports; allowing the steam to condense on the tissue within the first enclosed treatment space to circumferentially ablate the tissue; removing the first ablation catheter from the gastrointestinal tract; and examining the tissue. The procedure involves ablating a tissue area using a first ablation catheter to identify tissue blocks requiring concentrated ablation; inserting a second ablation catheter into the gastrointestinal tract via an endoscope, wherein the second ablation catheter includes a distal attachment or positioning element and at least one delivery port located at the distal end of the catheter; dilating the distal attachment or positioning element to form a second seal between the periphery of the distal attachment or positioning element and the gastrointestinal tract, and forming a second enclosed treatment space between the distal attachment or positioning element and the surface of the patient's gastrointestinal tract; delivering steam via the at least one port; allowing the steam to condense on the tissue within the second enclosed treatment space to concentrate tissue ablation; and removing the second ablation catheter from the gastrointestinal tract.

[0119] The above and other embodiments of the invention will be described in more detail in the accompanying drawings and detailed description provided below. Attached Figure Description

[0120] These and other features and advantages of the invention will be further understood when considered in conjunction with the accompanying drawings and with reference to the detailed description, wherein:

[0121] Figure 1A An ablation system according to an embodiment of this specification is shown;

[0122] Figure 1B This is a cross-sectional view of the flexible heating chamber according to an embodiment of this specification;

[0123] Figure 1C Transverse and longitudinal cross-sectional views of the first and second electrode arrays of the flexible heating chamber according to embodiments of this specification are shown;

[0124] Figure 1D According to the embodiments of this specification Figure 1B A cross-sectional view of the heating chamber, including the assembled first and second electrode arrays;

[0125] Figure 1E According to the embodiments of this specification Figure 1B A longitudinal cross-sectional view of the heating chamber, including the assembled first and second electrode arrays;

[0126] Figure 1F is a first longitudinal view of two heating chambers of a catheter according to an embodiment of the present specification arranged in series in a catheter tip; Figure 1B

[0127] Figure 1G is a second longitudinal view of two heating chambers of a catheter according to an embodiment of the present specification arranged in series in a catheter tip; Figure 1B

[0128] Figure 1H shows a multi-lumen balloon catheter incorporating one heating chamber according to an embodiment of the present specification; Figure 1B

[0129] Figure 1I shows a multi-lumen balloon catheter incorporating two heating chambers according to an embodiment of the present specification; Figure 1B

[0130] Figure 1J is a multi-step flowchart of a procedure for ablating Barrett's esophagus tissue in a patient's esophagus using a catheter according to one embodiment of the present specification; Figure 1H Figure 1I

[0131] Figure 1K shows a catheter having proximal and distal positioning elements and electrode heating chambers according to an embodiment of the present specification;

[0132] Figure 1L is a flowchart showing a method of ablating tissue within a patient's gastrointestinal tract according to some embodiments of the present specification;

[0133] Figure 1M is a flowchart showing a method of ablating tissue within a patient's gastrointestinal tract according to other embodiments of the present specification;

[0134] Figure 1N is a flowchart showing a method of treating a patient's gastrointestinal disease using a steam ablation system according to an embodiment of the present specification;

[0135] Figure 2A shows a perspective view of a needle ablation device according to an embodiment of the present specification;

[0136] Figure 2B shows a cross-sectional view of a needle ablation device according to an embodiment of the present specification; Figure 2A

[0137] shows a first enlarged cross-sectional view of a needle ablation device according to an embodiment of the present specification; Figure 2C Figure 2A

[0138] Figure 2D ​​​​​​​​​​​​A perspective view of a needle ablation device according to an embodiment of the present specification is shown. Figure 2A A second enlarged cross-sectional view of a needle ablation device according to an embodiment of the present specification is shown.

[0139] Figure 3A A perspective view of an endoscope and a needle ablation device deployed through the endoscope according to an embodiment of the present specification is shown. Figure 2A A perspective view of a needle ablation device according to an embodiment of the present specification is shown.

[0140] Figure 3B A perspective view of a curved portion of an endoscope according to an embodiment of the present specification is shown.

[0141] Figure 4A A perspective view of a needle of a needle ablation device according to an embodiment of the present specification is shown.

[0142] Figure 4B Another perspective view of a needle of a needle ablation device according to an embodiment of the present specification is shown. Figure 4A

[0143] A cross-sectional view of a needle of a needle ablation device according to a first embodiment of the present specification is shown. Figure 4C Figure 4A A cross-sectional view of a needle of a needle ablation device according to a second embodiment of the present specification is shown.

[0144] Figure 4D Figure 4A A perspective view of various needles according to an embodiment of the present specification is shown, showing a needle tip portion and an insulating coating.

[0145] Figure 4E A perspective view of one needle of a needle ablation catheter having variable stiffness along its length according to an embodiment of the present specification is shown.

[0146] Figure 5A A perspective view of a plurality of needles of a needle ablation catheter having variable stiffness along its length according to some embodiments of the present specification is shown.

[0147] Figure 5B First and second needles of a needle ablation catheter having different laser cut portions according to some embodiments of the present specification are shown.

[0148] Figure 5C A plurality of laser cut patterns of a needle of a needle ablation catheter according to some embodiments of the present specification is shown.

[0149] Figure 5D A first cross-sectional view of a catheter for insertion into a needle of a needle ablation device according to an embodiment of the present specification is shown.

[0150] Figure 6A A second cross-sectional view of a catheter for insertion into a needle of a needle ablation device according to an embodiment of the present specification is shown. Figure 2A

[0151] Figure 6B ​​​According to the embodiments of this specification Figure 6A Second sectional view of the duct;

[0152] Figure 6C Some embodiments according to this specification are shown. Figure 6A The first plurality of structures of the expandable end of the catheter;

[0153] Figure 6D Some embodiments according to this specification are shown. Figure 6A The second or multiple configurations of the expandable end of the catheter;

[0154] Figure 7A An ablation device with a coaxial catheter design according to an embodiment of this specification is shown;

[0155] Figure 7B A positioning device partially deployed according to an embodiment of this specification is shown;

[0156] Figure 7C A fully deployed positioning device according to an embodiment of this specification is shown;

[0157] Figure 7D An ablation device with a conical positioning element according to an embodiment of this specification is shown;

[0158] Figure 7E An ablation device with a disc-shaped positioning element according to an embodiment of this specification is shown;

[0159] Figure 8A A conical cover-shaped positioning element according to an embodiment of this specification is shown;

[0160] Figure 8B A cross-sectional view of a conical cover-shaped positioning element according to an embodiment of this specification is shown;

[0161] Figure 8C A ball-and-socket connection from a conical shroud-shaped positioning element to the end of a catheter, according to an embodiment of this specification, is shown.

[0162] Figure 8D A cross-sectional view is shown of a conical shroud-shaped positioning element connected to the end of a catheter according to one embodiment of this specification;

[0163] Figure 8E A perspective view of a conical cap-shaped positioning element connected to the end of a catheter according to an embodiment of this specification is shown;

[0164] Figure 8F A first construction of the conical cover-shaped positioning element according to an embodiment of this specification is shown;

[0165] Figure 8G A second construction of the conical cover-shaped positioning element according to an embodiment of this specification is shown;

[0166] Figure 8H A third configuration of a conical cup-shaped positioning element is shown in accordance with embodiments of the present specification;

[0167] Figure 8I A fourth configuration of a conical cup-shaped positioning element having a pyramidal base is shown in accordance with embodiments of the present specification;

[0168] Figure 8J An ablation catheter having a conical attachment or positioning element and an electrode heating chamber is shown in accordance with some embodiments of the present specification;

[0169] Figure 9A is a flowchart showing a method of ablating tissue within a patient's gastrointestinal tract in accordance with some embodiments of the present specification;

[0170] Figure 9B is a flowchart showing a method of ablating tissue within a patient's gastrointestinal tract in accordance with other embodiments of the present specification;

[0171] Figure 9C is a flowchart showing a method of performing circumferential ablation using a first ablation catheter and then performing focal ablation using a second ablation catheter in accordance with some embodiments of the present specification;

[0172] Figure 9D is a flowchart showing a multi-stage method of performing duodenal ablation to treat obesity, overweight, eating disorders, metabolic syndrome, diabetes, dyslipidemia, non-alcoholic steatohepatitis, non-alcoholic fatty liver, or polycystic ovary disease using a steam ablation system in accordance with embodiments of the present specification;

[0173] Figure 9E is a flowchart showing a multi-stage method of treating cancerous or precancerous esophageal tissue using a steam ablation system in accordance with various embodiments of the present specification;

[0174] Figure 10A First and second graphs showing energy consumption curves of a heating chamber (flexible heating chamber with RF electrode or induction coil-based heating chamber) and pressure curves of steam generated during an ablation treatment are shown in accordance with embodiments of the present specification;

[0175] Figure 10B An alarm generated when the steam pressure of a heating chamber reaches above a predetermined limit is shown in accordance with embodiments of the present specification;

[0176] Figure 10C Third and fourth graphs showing temperature profiles of steam generated during an ablation treatment and pressure profiles of steam are shown in accordance with embodiments of the present specification;

[0177] Figure 10DA first pressure treatment profile according to an embodiment of the present specification is shown;

[0178] Figure 10E A plurality of cycles of a first pressure treatment profile according to an embodiment of the present specification is shown;

[0179] Figure 10F A plurality of cycles of a first pressure treatment profile according to another embodiment of the present specification is shown;

[0180] Figure 10G A second pressure treatment profile according to an embodiment of the present specification is shown;

[0181] Figure 10H A second pressure treatment profile according to another embodiment of the present specification is shown;

[0182] Figure 10I A second pressure treatment profile according to another embodiment of the present specification is shown;

[0183] Figure 10J A plurality of cycles of a second pressure treatment profile according to an embodiment of the present specification is shown;

[0184] Figure 10K A third pressure treatment profile according to an embodiment of the present specification is shown;

[0185] Figure 10L A plurality of cycles of a pair of pressure profiles according to an embodiment of the present specification is shown;

[0186] Figure 10M A plurality of cycles of a fourth pressure profile according to an embodiment of the present specification is shown;

[0187] Figure 10N A plurality of cycles of a fifth pressure profile according to an embodiment of the present specification is shown;

[0188] Figure 10O A plurality of cycles of a sixth pressure profile according to an embodiment of the present specification is shown;

[0189] Figure 10P A plurality of cycles of a seventh pressure profile according to an embodiment of the present specification is shown;

[0190] Figure 11A A single lumen double balloon catheter according to one embodiment of the present specification is shown, including an inline heating element;

[0191] Figure 11B A coaxial lumen double balloon catheter according to one embodiment of the present specification is shown, including an inline heating element;

[0192] Figure 11C is used according to one embodiment of the present specification,Figure 11A A flowchart illustrating the multiple steps of ablation performed by a catheter in a body cavity (such as a patient's Barrett's esophagus);

[0193] Figure 12A This is an assembly diagram of a steam generation system according to an embodiment of this specification;

[0194] Figure 12B yes Figure 12A An exploded view of the upstream components of the induction heating unit of the steam generation system;

[0195] Figure 12C yes Figure 12A An exploded view of the downstream components of the induction heating unit in the steam generation system;

[0196] Figure 13A The de-energized state of the three-way flow control solenoid valve is shown.

[0197] Figure 13B The energization status of the three-way flow control solenoid valve is shown;

[0198] Figure 14A A dual-balloon multi-lumen catheter system according to an embodiment of this specification is shown;

[0199] Figure 14B Two elongated conduit shafts according to embodiments of this specification are shown;

[0200] Figure 14C A first eyelet pattern according to an embodiment of this specification is shown;

[0201] Figure 14D A second eyelet pattern according to an embodiment of this specification is shown;

[0202] Figure 14E An embodiment according to this specification is shown. Figure 14A A cross-sectional view of the multi-lumen axis of the catheter system;

[0203] Figure 15A A telescopic conduit handle according to an embodiment of this specification is shown, wherein a first handle component is in a first position relative to a second handle component;

[0204] Figure 15B A telescopic conduit handle according to an embodiment of this specification is shown, wherein a first handle component is in a second position relative to a second handle component;

[0205] Figure 15C An induction heating unit connected in series with the proximal end of the catheter handle according to an embodiment of this specification is shown;

[0206] Figure 15DAn exploded view of the second handle component of the catheter handle according to an embodiment of this specification is shown;

[0207] Figure 15E A perspective view of a second handle component separated from a first handle component of a catheter handle, according to an embodiment of this specification, is shown;

[0208] Figure 15F A cross-sectional view of a second handle component of a catheter handle according to an embodiment of this specification is shown;

[0209] Figure 15G An exploded view of a first handle component of a catheter handle according to an embodiment of this specification is shown;

[0210] Figure 15H This is a cross-sectional view of the first handle component of the catheter handle according to an embodiment of this specification;

[0211] Figure 16A A single multi-cavity shaft according to an embodiment of this specification is shown;

[0212] Figure 16B An embodiment according to this specification is shown. Figure 16A The pattern of steam exiting the port on a portion of the shaft;

[0213] Figure 16C According to the embodiments of this specification Figure 16A The first sectional view of the axis;

[0214] Figure 16D According to the embodiments of this specification Figure 16A The second sectional view of the axis;

[0215] Figure 16E This is a perspective view of a non-retractable catheter handle according to an embodiment of this specification;

[0216] Figure 16F This is a partial cross-sectional view of a non-retractable catheter handle according to an embodiment of this specification;

[0217] Figure 17A A clamp according to an embodiment of this specification is shown;

[0218] Figure 17B A clamp detachably connected to the endoscope shaft according to an embodiment of this specification is shown;

[0219] Figure 17C An induction heating unit, which is mounted separately from the catheter handle (also mounted on the endoscope) on the endoscope according to an embodiment of this specification, is shown.

[0220] Figure 17D This specification illustrates a slidable mounting to an embodiment of the present invention.Figure 17A The components of the induction heating unit on the clamp

[0221] Figure 18 This is a schematic diagram of an embodiment of a disposable catheter device used with the ablation system described in this specification;

[0222] Figure 19 This is a view of a telescopic catheter handle attached to an endoscope according to an embodiment of this specification;

[0223] Figure 20A This is an assembly view of a steam generator according to an embodiment of this specification;

[0224] Figure 20B This is a partial exploded view of a steam generator according to an embodiment of this specification;

[0225] Figure 20C This is an exploded view of the disposable pump of the steam generator according to an embodiment of this specification;

[0226] Figure 20D This is an assembly view of a disposable pump according to an embodiment of this specification;

[0227] Figure 20E A disposable pump, fluidly connected to other components of a steam generator according to an embodiment of this specification, is shown.

[0228] Figure 21 An ablation catheter, according to one embodiment of this specification, is shown placed in the upper gastrointestinal tract with a Barrett esophagus to selectively ablate Barrett tissue;

[0229] Figure 22 This is a flowchart illustrating a Barrett esophageal ablation method according to one embodiment of this specification;

[0230] Figure 23A The following are shown: a deflated view, a lateral inflated view, and a front inflated view of an ablation catheter having a barrier membrane for duodenal ablation according to an embodiment of this specification.

[0231] Figure 23B An ablation catheter deployed in the duodenum of a patient is shown according to one embodiment of this specification;

[0232] Figure 24 This is a flowchart illustrating a colon ablation method according to one embodiment of this specification;

[0233] Figure 25 An upper gastrointestinal tract according to one embodiment of this specification is shown, the upper gastrointestinal tract having hemorrhagic vascular lesions treated by an ablation device;

[0234] Figure 26is a flowchart illustrating an upper gastrointestinal tract ablation method according to one embodiment of the present specification;

[0235] Figure 27A is an illustration of a pancreatic ablation of a pancreatic tumor according to one embodiment of the present specification;

[0236] Figure 27B is a flowchart listing steps involved in one embodiment of a pancreatic ablation method;

[0237] Figure 27C is a flowchart listing steps involved in one embodiment of a pancreatic cyst ablation method;

[0238] Figure 28 is a flowchart listing steps involved in one embodiment of a tissue ablation method in the biliary duct;

[0239] Figure 29A is a flowchart illustrating a bronchial alveolar tissue ablation method according to an embodiment of the present specification;

[0240] Figure 29B is a flowchart illustrating a bronchial tract tissue ablation method according to another embodiment of the present specification;

[0241] Figure 30A shows a cross-sectional view of a catheter for performing bronchial hot shaping according to an embodiment of the present specification;

[0242] Figure 30B shows a plurality of channel patterns of a balloon of a catheter according to some embodiments of the present specification; Figure 30A

[0243] Figure 30C shows a workflow of a bronchial hot shaping procedure performed using a catheter according to an embodiment of the present specification; Figure 30A

[0244] Figure 31A shows a lung volume reduction (LVR) catheter according to an embodiment of the present specification;

[0245] Figure 31B shows an LVR catheter according to an embodiment of the present specification deployed through an endoscope / bronchoscope; Figure 31A

[0246] Figure 31C shows a workflow of a lung volume reduction performed using a catheter according to an embodiment of the present specification; Figure 31A

[0247] Figure 32A shows a needle catheter according to one embodiment incorporating a flexible heating chamber of Figures 1A-1D ​​​​​

[0248] Figure 32B a needle catheter incorporating two flexible heating chambers is shown Figure 32A in accordance with one embodiment;

[0249] Figure 32C is a flow chart showing one embodiment of a method of ablating tissue using a needle catheter Figure 32A DETAILED DESCRIPTION

[0250] Embodiments of the present specification provide ablation systems and methods for treating various indications, including but not limited to precancerous or cancerous tissue in the esophagus, duodenum, bile duct, and pancreas. In various embodiments, steam generated by heating saline is used as an ablation agent. In various embodiments, the ablation system includes a generator for generating an ablation agent (steam generator) including a source for providing a fluid (saline) to be converted into steam (steam) and a catheter for converting and delivering the steam, wherein the catheter includes at least one electrode embedded in a central lumen of the catheter and configured to function as a heating chamber to convert the saline into steam. The ablation system further includes an accessory at the distal end of the catheter, wherein the accessory includes at least one of a needle, a cap, a shield, or a disc. The accessory is configured to direct the delivery of the ablation agent. The catheter can further include a positioning element to position the catheter for optimal steam delivery. The accessory and the positioning element are configured to create a seal and form an enclosed treatment space for delivering steam and ablating target tissue. In some embodiments, the ablation systems and methods of the present specification are configured to enclose a region or space of tissue with at least one positioning accessory, fill the region or space with steam, allow the temperature in the region or space to rise above 100°C, then allow additional steam to escape, maintain the temperature above 100°C for a predetermined duration, and the pressure in the region or space is less than 5 atmospheres to allow the steam to condense and ablate the tissue.

[0251] The configuration of the various catheters of the ablation systems of embodiments of the present specification can vary based on the tissue or organ system being treated. For example, in some embodiments, the catheters for esophageal and duodenal ablation are similar, but the spacing between two positioning elements (positioned distal and proximal to the distal end portion of the catheter, with a steam delivery port between the two positioning elements) can be greater for esophageal applications (approximately 1-20 cm) than for duodenal applications (approximately 1-10 cm). The ablation distribution and depth provided by the systems and methods of the present specification depend on the duration of exposure to steam, the size of the ablation, the temperature of the steam, the time of contact with the steam, and the type of tissue.

[0252] ​In some embodiments, the patient is treated in a two-step procedure to ensure complete or nearly complete ablation of the target tissue. In some embodiments, the patient is first treated with a catheter having two positioning elements - a distal positioning element is first deployed, followed by a proximal positioning element, and a tube segment having a port located between the two positioning elements, thereby enabling a large area circumferential ablation. The positioning elements can be balloons, discs, or any other structure. A first seal is created by the outer periphery of the positioning elements in contact with the patient's tissue at the distal and proximal positioning elements. The creation of the first seal results in the formation of a first enclosed treatment space bounded on the sides by the distal positioning element at the distal end, the proximal positioning element at the proximal end, and the wall of the patient's tissue (e.g. the esophagus or the duodenum). Ablation energy in the form of steam is then delivered by the catheter into the first treatment space, where it condenses and contacts the patient's tissue for circumferential ablation, and cannot escape from the distal or proximal end because it is blocked by the positioning elements, or alternatively, controllably escapes from the distal or proximal end based on the configuration of the positioning elements, as further described below.

[0253] After ablation using a catheter with two positioning elements, the ablation area is examined by the physician. In observing the patient, the physician can identify a mass of tissue that requires focused ablation. A second step is then performed in which a second catheter with a needle or cap, shield or disc attachment at the distal end is passed through the endoscope and used for focused ablation. The needle provides directional, focused ablation, and the cap, shield or disc attachment encloses the area of focused ablation, creating a second seal and a second enclosed treatment space for ablation of tissue. The seal is formed by positioning at least a portion of the outer periphery of the cap, shield or disc attachment in contact with the surface of the patient's tissue (e.g. the esophagus or the duodenum), thereby positioning a portion of the patient's tissue within the area bounded by the attachment. When the seal is formed, a second treatment space is created that is configured to receive steam and is bounded on the sides by the attachment and the bounded portion of the patient's tissue. Ablation energy in the form of steam is then delivered by the catheter into the second treatment space via at least one port at the distal end of the catheter, where it condenses and contacts the patient's tissue for focused ablation, and cannot escape because it is bounded by the attachment, or controllably escapes from the attachment based on the configuration of the attachment, as further described below. In one embodiment, the flow of steam out of the enclosed or partially enclosed space is a predetermined percentage of the flow of steam into the enclosed or partially enclosed space from the port of the catheter, wherein the predetermined percentage is in the range of 1% to 80%, preferably less than 50%, and more preferably less than 30%. The at least one port is located at the distal end of the catheter such that when the attachment is positioned, the port enters the second treatment space.

[0254] In the first and second steps, when creating the enclosed first and second treatment spaces, it is preferable to avoid creating a complete (100%) seal. A complete seal would trap air in the treatment space. Relative to the steam used for ablation, the trapped air would not be hot, and thus, a "cold air pocket" would be created, which acts as a heat sink, consuming a portion of the thermal ablation energy of the steam, and causing uneven distribution of the ablation energy of the steam. Creating an incomplete seal allows air to be pushed out of the treatment space through gaps in the seal as the steam is delivered into the treatment space.

[0255] Further, as the temperature in the treatment space increases, no steam escapes until the temperature is greater than or equal to 100°C, at which point condensation of the steam stops, allowing the steam to escape through the gaps, preventing over-pressurization of the treatment space. In some embodiments, the catheter includes a filter having micropores that provide a back pressure to the delivered steam, thereby pressurizing the steam as it enters the treatment space from the catheter. The predetermined size of the micropores in the filter determines the back pressure, and thus the temperature of the steam that is generated. In the ablation process with the two-positioning element accessory, in various embodiments, the gaps or incomplete seal are located only at the distal positioning element, only at the proximal positioning element, or at both the distal and proximal positioning elements.

[0256] To create the gaps or less-than-ideal seal and allow air to leak or be pushed out of the treatment space, embodiments of the present specification provide positioning elements or accessories that have a surface area in the range of 40% to 99% of the surface area that contacts the patient's tissue. In some embodiments, the surface area along a cross-sectional slice of the plane where the positioning element or accessory contacts the tissue is in the range of 20% to 99%. A low value (e.g., 20%) indicates a very porous seal, indicating that there is a gap between the positioning element or accessory and the tissue, or that the positioning element or accessory includes voids therein, while a high value (e.g., 99%) indicates an almost complete seal. Additionally, the first and second seals are considered to be low-pressure seals, where the pressure within the first and second treatment spaces formed by the seals is less than 5 atmospheres, and typically close to 1 atmosphere. Thus, when the pressure rises above a predetermined pressure level, the seal is broken, and the heated air or steam is allowed to escape, thereby eliminating the need for a pressure sensor in the catheter itself.

[0257] In some embodiments, one or more of the positioning elements or accessories are configured such that they allow a range of fluid outflow from the treatment space enclosed by the two positioning elements or accessories. The amount of outflow allowed is a function of the steam inflow to the enclosed space, thereby acting as a safety valve and allowing the desired pressure range (less than 5 atmospheres) to be maintained without adjustment by the steam generator itself. In some embodiments, the positioning elements or accessories include multiple spaces within the surface area of the positioning elements or accessories and / or between the perimeter of the positioning elements or accessories and the tissue that are sufficient to allow fluid outflow from the enclosed space in the range of 1% to 80% of the steam input flow to maintain the pressure level within the enclosed space at less than 5 atmospheres without adjustment from the steam generator.

[0258] In some embodiments, when the surface area of the mucosa to be ablated is in the range of 5 square centimeters (cm 2 ) to 200 cm 2 , the enclosed space is in the range of 3 cubic centimeters (cc) to 450 cc.

[0259] In some embodiments, one or more of the positioning elements or accessories are deformable during treatment. The positioning elements and accessories according to embodiments of the present description are designed to physically modify or deform when the pressure in the treatment space increases above 10% of the baseline pressure, thus effectively acting as a pressure relief valve. Due to the ability to deform, the outflow from the space enclosed by the two positioning elements or accessories is variable. In one exemplary embodiment, at the beginning of treatment, only a small fraction (if any) of the outflow from the enclosed space is blocked. During treatment, due to pressure changes, the percentage of blocked flow decreases, thus increasing the leak. In some embodiments, assuming that at the beginning of treatment the positioning elements or accessories block the outflow from the enclosed space (or have a cross-sectional area covered) in the range of 100% (all flow blocked or all cross-sectional area covered) to 20% (only 20% of the flow blocked or only 20% of the cross-sectional area covered), during treatment, this percentage changes, with the amount of blocked / cross-sectional area decreasing by 1% to 25% relative to the starting percentage. In various embodiments, as previously mentioned, it is preferable that a pressure sensor not be included in the catheter itself to reduce cost and possible sensor failure. Thus, the deformable positioning elements naturally act as safety valves without the need for active pressure sensing.

[0260] In various embodiments, the ablation devices and catheters described in this specification are used in conjunction with any one or more heating systems described in U.S. Patent Application No. 14 / 594,444, entitled "Method and Apparatus for Tissue Ablation," filed on January 12, 2015, and issued as U.S. Patent No. 9,561,068 on February 7, 2017, the entire contents of which are hereby incorporated by reference.

[0261] "Treating" and variations thereof mean any decrease in the extent, frequency, or severity of one or more symptoms or signs associated with a disorder.

[0262] "Durations" and variations thereof refer to the temporal course of a prescribed treatment from beginning to end, whether the treatment ends because the condition has been resolved or the treatment is suspended for any reason. During the duration of the treatment, multiple treatment cycles can be prescribed during which one or more prescribed stimuli are applied to the subject.

[0263] "Cycles" refer to the time during which a "dose" of stimulation is administered to a subject as part of a prescribed treatment plan.

[0264] The term "and / or" means one or all of the listed elements or any combination of two or more of the listed elements.

[0265] In the description and claims of the application, each of the words "comprise," "include" and "have," and forms of the above terms, does not exclude the presence of other elements or limit the part of the process, machine, manufacture, composition of matter, means, methods, etc. that comprises, includes, or has those elements or steps. The terms "comprising," "including," and "having" and variations thereof as used herein are intended to be equivalent to the term "consisting of" and to the term "consisting entirely of," when the words "consisting of" or "consisting entirely of" are recited in the claims.

[0266] Unless otherwise indicated, "a," "an," "the," and "at least one" are used interchangeably and mean one or more.

[0267] The term "controller" refers to an integrated hardware and software system defined by a plurality of processing elements (e.g., integrated circuits, application specific integrated circuits, and / or field programmable gate arrays) in data communication with memory elements (e.g., random access memory or read only memory) in which one or more processing elements are configured to execute programmed instructions stored in one or more memory elements.

[0268] The term "steam generation system" refers to any or all of the heater or induction based methods described in this application for generating steam from water.

[0269] For any method disclosed herein that includes discrete steps, the steps can be conducted in any feasible order. And, whenever appropriate, two or more steps can be combined into a single step.

[0270] Further, as used herein, recitation of ranges of values includes all values within the range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Unless otherwise indicated, all numbers used herein to express quantities, molecular weight, etc., are to be understood as "about" the actual value used. Accordingly, unless otherwise indicated, the numerical parameters set forth in the specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, each numerical parameter should at least be construed in light of the number of significant digits it contains and by applying ordinary rounding techniques.

[0271] Notwithstanding that the numerical ranges and parameters setting forth the broadest scope of the present specification are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0272] The devices and methods of the present disclosure can be used to perform controlled local or circumferential ablation of varying depths to the target tissue in a manner that allows for complete healing with re-epithelialization. In addition, the steam can be used to treat / ablate benign and malignant tissue growths, resulting in destruction, liquefaction, and absorption of the ablated tissue. The dosage and manner of treatment can be adjusted according to the type of tissue and the desired depth of ablation. The ablation device can be used not only to treat cardiac arrhythmias, Barrett's esophagus and esophageal dysplasia, flat colonic polyps, gastrointestinal bleeding lesions, endometrial ablation, lung ablation, but also to treat any mucosal, submucosal, or circumferential lesions, such as inflammatory lesions, tumors, polyps, and vascular lesions. The ablation device can also be used to treat local or circumferential mucosal or submucosal lesions of any hollow organ or hollow body passageway in the body. The hollow organ can be one of the gastrointestinal tract, the biliary and pancreatic ducts, the genitourinary tract, the respiratory tract, or a vascular structure such as a blood vessel. The ablation device can be placed by endoscopy, radiology, surgical procedure, or direct visualization. In various embodiments, a wireless endoscope or a single fiber endoscope can be incorporated as part of the device. In another embodiment, magnetic navigation or stereotactic navigation can be used to navigate the catheter to the desired location. Radiopaque or echogenic materials can be incorporated into the catheter body for radiological positioning. Iron or ferromagnetic materials can be incorporated into the catheter to assist with magnetic navigation.

[0273] Ablation agents (e.g., steam, heated gas, or cryogen, such as but not limited to liquid nitrogen) are inexpensive and readily available, and are directed onto the tissue through infusion ports, held at a fixed and consistent distance, with the goal of ablation. This allows for uniform distribution of the ablation agent over the target tissue. The flow of the ablation agent is controlled by a microprocessor according to a predetermined method based on the characteristics of the tissue to be ablated, the desired depth of ablation, and the distance of the ports from the tissue. The microprocessor can use temperature, pressure, or other sensory data to control the flow of the ablation agent. In addition, one or more suction ports are provided to suction the ablation agent from the vicinity of the target tissue. The target segment can be treated by continuous infusion of the ablation agent or by cycles of infusion and removal of the ablation agent determined and controlled by the microprocessor.

[0274] It should be understood that the devices and embodiments described herein are implemented in conjunction with a controller that includes a microprocessor that executes control instructions. The controller can be in the form of any computing device, including desktop, laptop, and mobile devices, and can communicate control signals to the ablation device in wired or wireless form.

[0275] The present invention is directed to a number of embodiments. The following disclosure is provided in order to enable any person skilled in the art to practice the invention. Language used in this specification should not be interpreted as a general disavowal of any one specific embodiment nor used to limit the meaning of terms to forms described under that term. The general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the invention. Additionally, the terminology and phraseology used is for the purpose of description and should not be regarded as limiting. Thus, the present invention is to be afforded the broadest scope permissible under the law as set forth in the two widest claims recited below. For clarity, details relating to technical field of the invention have not been set forth in order to not unnecessarily obscure the disclosure regarding the present invention.

[0276] It should be noted here that any feature or component described in association with a particular embodiment can be used and implemented with any other embodiment, unless explicitly stated otherwise.

[0277] Figure 1AAn ablation system 100 according to embodiments of the present specification is shown. The ablation system includes a catheter 10 having at least one first distal attachment or positioning element 11 and an internal heating chamber 18 disposed in the lumen of the catheter 10 and configured to heat a fluid provided to the catheter 10 to change the fluid to a vapor for use in ablation therapy. In some embodiments, the catheter 10 is made of or covered with an insulating material to prevent ablation energy from escaping from the catheter body. The catheter 10 includes one or more infusion ports 12 for infusion of an ablation agent, such as a vapor. In some embodiments, the one or more infusion ports 12 include a single infusion port at the distal end of the needle. In some embodiments, the catheter includes a second positioning element 13 proximate to the infusion port 12. In various embodiments, the first distal attachment or positioning element 11 and the second positioning element 13 can be any of a disc, a shield, a cap, or an inflatable balloon. In some embodiments, the first distal attachment or positioning element 11 and the second positioning element 13 include holes 19 for air or ablation agent escape. A fluid, such as saline, is stored in a reservoir, such as a saline pump 14, connected to the catheter 10. Delivery of the ablation agent is controlled by a controller 15, and the therapy is controlled by the treating physician through the controller 15. The controller 15 includes at least one processor 23 in data communication with the saline pump 14 and a catheter connection port 21 in fluid communication with the saline pump 14. In some embodiments, at least one optional sensor 17 monitors changes in the ablation region to direct the flow of the ablation agent. In some embodiments, the optional sensor 17 includes at least one of a temperature sensor or a pressure sensor. In some embodiments, the catheter 10 includes a filter 16 having micropores that provide back pressure to the delivered vapor, thereby pressurizing the vapor. The predetermined size of the micropores in the filter determines the back pressure, and thus the temperature of the vapor generated. In some embodiments, the system further includes a foot pedal 25 in data communication with the controller 15, a switch 27 on the catheter 10, or a switch 29 on the controller 15 for controlling the vapor flow.

[0278] In one embodiment, the user interface included in the microprocessor 15 allows the physician to define the device, organ, and condition, which in turn creates default settings for temperature, cycle, volume (sound), and standard RF settings. In one embodiment, the physician can further modify these default values. The user interface also includes standard displays of all key variables, as well as alerts for values that exceed or fall below certain levels.

[0279] The ablation device also includes safety mechanisms to prevent the user from being burned while operating the catheter, including insulation, and optionally, a cold air flush, a cold water flush, and an alarm / tone that indicates the start and stop of therapy.

[0280] Figure 1Bis a cross-sectional view 121 of a flexible heating chamber 130 according to embodiments of the present specification, configured to be incorporated at or in a distal portion or tip of a catheter. Figure 1C are shown are lateral and longitudinal cross-sectional views 122a, 122b of a first electrode array 136 and lateral and longitudinal cross-sectional views 123a, 123b of a second electrode array 138 of a flexible heating chamber for a catheter according to embodiments of the present specification. Figure 1D and 1E are lateral and longitudinal cross-sectional views 124, 125 of a heating chamber 130 including assembled first and second electrodes 136, 138, respectively.

[0281] Reference is now made to Figure 1B , 1C , 1E and 1E, the heating chamber 130 includes an outer housing 132 and a coaxial inner core, channel or lumen 134. A plurality of electrodes configured as first and second electrode arrays 136, 138 are disposed between the outer housing 132 and the inner lumen 134. In some embodiments, the first and second electrode arrays 136, 138 include metal rings 142, 144, respectively, from which a plurality of electrode fins or elements 136’, 138’ radially extend into the space between the outer housing 132 and the inner lumen 134 (see 122a, 123a). The electrode fins or elements 136’, 138’ also extend longitudinally along a longitudinal axis 150 of the heating chamber 130 (see 122b, 123b). In other words, each electrode fin 136’, 138’ has a first dimension along a radius of the heating chamber 130 and a second dimension along the longitudinal axis 150 of the heating chamber 130. The electrode fins or elements 136’, 138’ define a plurality of segmented spaces 140 therebetween through which saline / water flows and evaporates into vapor. Current is directed from a controller through the inner lumen into the catheter and to the electrodes 136, 138, which causes the fins or elements 136’, 138’ to generate heat, which is then transferred to the saline in order to convert the saline into vapor. The first and second dimensions enable the electrodes 136, 138 to have an increased surface area for heating the saline / water flowing in the spaces 140. According to one embodiment, the first electrodes 136 have a first polarity and the second electrodes 138 have a second polarity opposite to the first polarity. In one embodiment, the first polarity is negative (cathode) and the second polarity is positive (anode).

[0282] In some embodiments, the outer cover 132 and the inner lumen 134 are composed of silicone, Teflon, ceramic, or any other suitable thermoplastic elastomer known to those of ordinary skill in the art. The inner lumen 134, the outer cover 132, the electrodes 136, 138 (including the rings 142, 144 and the fins or elements 136', 138') are all flexible to allow the distal portion or tip of the catheter to be bent, providing better catheter positioning during ablation procedures. In some embodiments, the inner lumen 134 stabilizes the electrodes 136, 138 and maintains the spacing or pitch 140 between the electrodes 136, 138 when the catheter tip is bent or folded during use.

[0283] As shown in Figure 1D and 1E , when the heating chamber 130 is assembled, the electrode fins or elements 136', 138' cross or interlock with each other (similar to the fingers of two clasped hands) such that a cathode element is followed by an anode element, the anode element is followed by a cathode element, the cathode element is followed by an anode element, and so on, with the spaces 140 separating each cathode and anode element. In various embodiments, each space 140 has a distance from a cathode element to an anode element in the range of 0.01 mm to 2 mm. In some embodiments, the first electrode array 136 has a range of 1 to 50 electrode fins 136', with a preferred number of 4 electrode fins 136', while the second electrode array 138 has a range of 1 to 50 electrode fins 138', with a preferred number of 4 electrode fins 138'. In various embodiments, the heating chamber 130 has a width w in the range of 1 to 5 mm and a length / in the range of 5 to 50 mm.

[0284] According to one aspect of the present description, a plurality of heating chambers 130 can be arranged in the catheter tip. Figure 1F and 1G is a longitudinal cross-sectional view of a catheter tip 155 according to embodiments of the present description, in which two heating chambers 130 are arranged in series. Referring to Figure 1F and 1G , the two heating chambers 130 are arranged in series such that the space 160 between the two heating chambers 130 acts as a hinge to impart additional flexibility to the catheter tip 155, allowing it to be bent. The two heating chambers 130 each include first and second electrode arrays 136, 138 that cross. The use of multiple (e.g., two) heating chambers 130 enables further increasing the surface area of the electrodes 136, 138 while maintaining the flexibility of the catheter tip 155.

[0285] Reference is now made to Figures 1B-1GTo generate steam, fluid is delivered from a container such as a syringe to the heating chamber 130 via a pump or other pressurizing device. In some embodiments, the fluid is sterile saline or water delivered at a constant or variable flow rate. An RF generator connected to the heating chamber 130 supplies power to the first and second electrode arrays 136, 138. Figure 1E As shown, during steam generation, when fluid flows through space 140 in heating chamber 130 and electricity is applied to electrodes 136 and 138 to heat them, the fluid is heated in the first proximal region 170 of heating chamber 130. When the fluid is heated to a sufficient temperature, such as 100 degrees Celsius below atmospheric pressure, the fluid begins to transform into steam in the second intermediate region 175. When the fluid reaches the third distal region 180, all the fluid has transformed into steam, after which the fluid can exit the distal end 133 of heating chamber 130 and exit the conduit end 155. If the pressure in the heating chamber is greater than atmospheric pressure, a higher temperature will be required; if it is lower than atmospheric pressure, a lower temperature will generate steam.

[0286] In one embodiment, the sensor probe may be located at the distal end of the heating chamber within the catheter. During steam generation, the sensor probe transmits a signal to a controller. The controller can use this signal to determine whether the fluid has fully converted into steam before leaving the distal end of the heating chamber. Sensing whether saline has been fully converted into steam can be particularly useful for many surgical applications, such as in the ablation of various tissues, where delivering high-quality (low water content) steam enables more effective treatment. In some embodiments, the heating chamber includes at least one sensor 137. In various embodiments, the at least one sensor 137 includes an impedance, temperature, pressure, or flow sensor, with a pressure sensor being less preferred. In one embodiment, the impedance of the electrode arrays 136, 138 may be sensed. In other embodiments, the temperature of the fluid, the temperature of the electrode array, the fluid flow rate, pressure, or similar parameters may be sensed.

[0287] Figure 1H and Figure 1I Multi-lumen balloon catheters 161 and 171 according to embodiments of this specification are shown respectively. Catheters 161 and 171 each include an elongated body 162 and 172 having a proximal end and a distal end. Catheters 161 and 171 include at least one positioning element near their distal end. In various embodiments, the positioning element is a balloon. In some embodiments, the catheter includes more than one positioning element.

[0288] exist Figure 1H and 1IIn the illustrated embodiment, the catheters 161, 171 each include a proximal balloon 166, 176 and a distal balloon 168, 178, with the distal balloon 168, 178 located near the distal end of the body 162, 172, and a plurality of infusion ports 167, 177 located on the body 162, 172 between the two balloons 166, 176 and 168, 178. The body 162, 172 also includes at least one heating chamber 130 located proximate and immediately proximate the proximal balloon 166, 176. Figure 1H The embodiment of FIG. 1 illustrates one heating chamber 130 included in the body 165, which is located proximate and immediately proximate the proximal balloon 166. In some embodiments, multiple heating chambers are arranged in series in the catheter body.

[0289] In the embodiment of FIG. 1, the catheter 161 includes a proximal balloon 166 and a distal balloon 168, with the distal balloon 168 located near the distal end of the body 162. The body 162 also includes a plurality of infusion ports 167 located on the body 162 between the two balloons 166 and 168. The body 162 also includes at least one heating chamber 130 located proximate and immediately proximate the proximal balloon 166. Figure 1I In the embodiment of FIG. 1, the catheter 161 includes a proximal balloon 166 and a distal balloon 168, with the distal balloon 168 located near the distal end of the body 162. The body 162 also includes a plurality of infusion ports 167 located on the body 162 between the two balloons 166 and 168. The body 162 also includes at least one heating chamber 130 located proximate and immediately proximate the proximal balloon 166. Figure 1I To inflate the balloons 176, 178 and provide current and liquid to the catheter 171, a fluid pump 179, an air pump 173, and an RF generator 184 are connected to the proximal end of the body 172. The air pump 173 pumps air through a first lumen (extending along the length of the body 172) via a first port to expand the balloons 176, 178 so that the catheter 171 is held in place for ablation therapy. In another embodiment, the catheter 171 includes additional air ports and additional air lumens so that the balloons 176, 178 can be expanded individually. The fluid pump 179 pumps fluid through a second lumen (extending along the length of the body 172) to the heating chamber 130. The RF generator 184 provides current to the electrodes 136, 138 Figure 1G The flexible heating chamber 130 imparts improved flexibility and maneuverability to the catheter 161, 171, allowing the physician to better position the catheter 161, 171 when performing an ablation procedure, such as ablating Barrett's esophageal tissue in a patient's esophagus.

[0290] Figure 1J is used in accordance with the embodiments of the present specification Figure 1IA flowchart of the steps performed by the catheter 161, 171 to perform a plurality of steps of ablation of Barrett's esophageal tissue in a patient's esophagus is shown. At step 185, the catheter 161, 171 is inserted into the patient's esophagus. At step 186, the distal balloon 168, 178 is positioned distal to a portion of the Barrett's esophagus, the proximal balloon 166, 176 is positioned proximal to a portion of the Barrett's esophagus, such that the infusion port 167, 177 is positioned in the portion of the Barrett's esophagus. At step 187, the balloons 166, 176 and 168, 178 are inflated using a gas pump to position the catheter 161, 171 in the esophagus. At step 188, fluid, such as water or saline, is provided to the catheter 161, 171 by a fluid pump. Finally, at step 189, current is provided to the electrodes 136, 138 using an RF generator to heat the electrodes and convert the fluid to steam, where the generated steam is delivered through the infusion port 167, 177 to ablate the patient's Barrett's esophageal tissue.

[0291] Figure 1K A catheter 191 having proximal and distal positioning elements 196, 198 and electrode heating chambers 130 is shown in accordance with embodiments of the present specification. The catheter 191 includes an elongated body 192 having a proximal end and a distal end. The catheter 191 includes a proximal positioning element 196 and a distal positioning element 198, the distal positioning element 198 positioned near the distal end of the body 192, a plurality of infusion ports 197 located on the body 192 between the two positioning elements 196, 198. The body 192 further includes at least one heating chamber 130 located in a central lumen. In some embodiments, the proximal and distal positioning elements 196, 198 include compressible disks that expand when deployed. In some embodiments, the proximal and distal positioning elements 196, 198 are constructed of a shape memory metal and are transformable from a first, compressed configuration for deployment through an endoscope lumen to a second, expanded configuration for treatment. In some embodiments, the disks include a plurality of holes 199 to allow air to escape at the beginning of the ablation process and to allow steam to escape once the pressure and / or temperature within the enclosed treatment space formed between the two positioning elements 196, 198 reaches a predetermined limit, as described above. In some embodiments, the catheter 191 includes a filter 193 having micropores that provides back pressure to the delivered steam, thereby pressurizing the steam. The predetermined size of the micropores in the filter determines the back pressure, and thus the temperature of the generated steam.

[0292] It should be understood that the filter 193 can be any structure that allows steam to escape from the port and restricts steam flow back into or upstream of the catheter. Preferably, the filter is a thin, porous metal or plastic structure located within the catheter lumen and near one or more ports. Alternatively, a one-way valve can be used that allows steam to escape from the port but does not return to the catheter. In one embodiment, the structure 193 can be a filter, valve, or porous structure positioned within 5 cm of the port, preferably within 0.1 cm to 5 cm of the port, more preferably within less than 1 cm of the port, where the port is defined as an actual opening that allows steam to escape from the catheter and enter the patient.

[0293] Figure 1L This is a flowchart illustrating a method for ablating tissue in a patient's gastrointestinal tract according to some embodiments of this specification. In some embodiments, Figure 1L The method describes circumferential steam ablation followed by concentrated steam ablation after patient observation to treat precancerous, cancerous, or other unwanted tissue in the esophagus, duodenum, bile duct, or pancreas. In some embodiments, the ablation catheters disclosed in this specification, such as Figure 1K The ablation catheter 191 is used to perform... Figure 1L Ablation methods.

[0294] At 102, an ablation catheter configured for the gastrointestinal (GI) tract is inserted into the patient's gastrointestinal tract. At 104, a seal is formed between the outer surface of the ablation catheter and the inner wall of the gastrointestinal tract, forming a treatment space. As explained in the embodiments of this specification, the seal is created by the expansion of one or more positioning elements of the ablation catheter. In some embodiments, the seal is temperature-dependent, and the seal breaks or becomes porous when the temperature or pressure within the sealed portion or treatment space exceeds a threshold. In one embodiment, this specific temperature is 90°C. In some embodiments, the seal is pressure-dependent, and the seal begins to leak when the pressure within the sealed portion or treatment space exceeds a specific pressure. In one embodiment, the specific pressure is 5 atmospheres. At 106, vapor is delivered through the ablation catheter to the sealed portion within the gastrointestinal tract while the seal remains in place. At 108, the vapor condenses on the treated tissue, thereby ablating the tissue.

[0295] Figure 1M This is a flowchart illustrating a method for ablating tissue in a patient's gastrointestinal tract according to other embodiments of this specification. In some embodiments, Figure 1M The method describes circumferential steam ablation followed by concentrated steam ablation after patient observation to treat precancerous, cancerous, or other unwanted tissue in the esophagus, duodenum, bile duct, or pancreas. In some embodiments, the ablation catheter disclosed in this specification (e.g., Figure 1K The ablation catheter 191 is used to perform... Figure 1Mablation method. At 112, an ablation catheter configured for a gastrointestinal (GI) tract is inserted into the GI tract of a patient. At 114, saline with variable flow is introduced into the GI tract through the ablation catheter. At 116, the saline is heated using RF energy to create steam that can be passed into the GI tract through the ablation catheter. In some embodiments, the flow of saline during steam delivery is different than the flow of saline during phases without delivery of therapy. In some embodiments, the flow of saline during therapy is lower than during no therapy. In some embodiments, the flow of saline during therapy is lower than during no therapy. At 118, the steam condenses on the tissue being treated, thereby ablating the tissue.

[0296] Exemplary treatment-gastrointestinal system

[0297] Figure 1Nis a flowchart showing a method of treating a patient for a gastrointestinal disorder using a steam ablation system according to embodiments of the present specification. In various embodiments, the disorder can include, but is not limited to, obesity, overweight, eating disorders, metabolic syndrome and diabetes, fatty liver, nonalcoholic fatty liver disease (NAFLD), or nonalcoholic steatohepatitis (NASH). The steam ablation system includes a controller having at least one processor in data communication with at least one pump and a catheter connection port in fluid communication with the at least one pump. At step 101, a proximal end of a first catheter is connected to the catheter connection port to place the first catheter in fluid communication with the at least one pump. The first catheter includes at least two positioning elements spaced along a length of the catheter and at least two ports between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein in the first configuration each of the at least two positioning elements is compressed within the catheter and in the second configuration each of the at least two positioning elements is expanded to at least partially lie outside the catheter. At step 103, the first catheter is positioned within the patient such that upon expansion into the second configuration, a distal positioning element of the at least two positioning elements is positioned within the patient's small intestine and a proximal positioning element of the at least two positioning elements is positioned more than 1 cm from the distal positioning element of the at least two positioning elements. Then, at step 105, each of the at least two positioning elements is expanded into their second configuration. At step 107, the controller is activated, wherein upon activation the controller is configured to cause the at least one pump to deliver saline into at least one lumen in the first catheter, and wherein upon activation the controller is configured to cause an electrical current to be delivered to at least one electrode located in the at least one lumen of the first catheter. The electrical current causes the electrode to heat and contact of the saline with the heated electrode converts the saline to steam that is delivered through the at least two ports to ablate gastrointestinal tissue. In various embodiments, each treatment dose delivered to the gastrointestinal tract includes the following parameters: treatment of 1-15 cm of continuous or non-continuous small intestine mucosa; treatment of at least 50% of the circumference of the small intestine; energy in the range of 5-25 J / cm 2 ; delivery period of 1-60 seconds; delivery rate of 5-2500 cal / sec; total dose of tissue to be ablated of 5-40 cal / gm; target tissue temperature of between 60°C to 110°C; steam temperature of between 99°C to 110°C; pressure in the gastrointestinal tract of less than 5 atmospheres, preferably less than 1 atmosphere.

[0298] At step 109, the controller turns off the delivery of saline and electrical current after a time period of 1 to 60 seconds. In some embodiments, the controller automatically turns off the delivery of saline and electrical current. At step 111, the controller is repeatedly activated to deliver saline into the lumen and to deliver electrical current to the at least one electrode until the physician terminates the procedure. In some embodiments, the system further comprises a foot pedal, a switch on the catheter, or a switch on the controller in data communication with the controller for controlling the steam flow, and step 111 is implemented using the foot pedal, the switch on the catheter, or the switch on the controller in data communication with the controller. At step 113, the first catheter is removed from the patient.

[0299] Then, at step 115, the physician waits at least six weeks before assessing the treatment effectiveness. In some embodiments, the physician waits in the range of six weeks to two years before assessing the treatment effectiveness. As disclosed in this specification, at step 117, the treatment effectiveness is determined by measuring at least one physiological parameter related to the gastrointestinal disease, and comparing the measured parameter to a desired therapeutic endpoint. If the therapeutic endpoint has been achieved, the treatment is completed at step 129. If the therapeutic endpoint has not been achieved, the ablation treatment is repeated at step 119.

[0300] It will be appreciated that while the above discussion is directed to duodenal ablation, any ablation catheter or system of this specification for ablating tissue in an organ can be used with a controller configured to limit the pressure generated by the ablation fluid (e.g., steam) within the organ to less than 5 atmospheres or 100 psi. In various embodiments, the organ can be a pancreatic cyst, esophagus, duodenum / small intestine, uterine cavity, prostate, bronchial, or alveolar space.

[0301] Needle vapor delivery device

[0302] Figure 2A A perspective view of a needle-based steam delivery device 2000 according to an embodiment of this specification is shown. The device 2000 includes a needle 2005 extending from a distal end 2011 of a compound handle 2010. The needle 2005 has a needle tip portion 2001 and is surrounded by an inner or middle catheter 2002 and an outer catheter 2003 at its proximal end. In some embodiments, the compound handle 2010 and the needle 2005 are hollow. In some embodiments, the needle 2005 is retractable within the compound handle 2010. In some embodiments, the needle 2005 is stainless steel, the middle catheter 2002 is PTFE (polytetrafluoroethylene), and the outer catheter 2003 is braided Teflon.

[0303] Figure 2Bis a cross-sectional view of the compound handle 2010 showing the needle 2005 emerging from the distal end 2011, the front or distal handle portion 2013, and the back or proximal handle portion 2014. The lumen 2008 extends from the proximal end 2012 to the distal end 2011 of the compound handle 2010 and is in fluid communication with the lumen 2024 of the needle 2005. Saline enters the lumen 2008 from the proximal end 2012 and vapor exits from at least one port 2007 located at the distal end 2006 of the needle 2005. The pressure sensor 2009 is located near the proximal end 2012 of the compound handle 2010.

[0304] Figure 2C An enlarged view of the front or distal handle portion 2013 of the compound handle 2010 is shown. Referring now to Figure 2B and 2C , the distal handle portion 2013 is an assembly comprising a front tube 2015 connected at its distal end to a distal lock 2016 and at its proximal end to a front handle 2017. A lock 2021 secures the front tube 2015 to the front handle 2017. A pressure sensor 2018 is located near the proximal end of the front handle 2017, while the pressure sensor 2009 is located near the proximal end 2012.

[0305] Figure 2D An enlarged view of the back or proximal handle portion 2014 of the compound handle 2010 is shown. Referring now to Figure 2B , 2C and 2D, the proximal handle portion 2014 is an assembly comprising a back tube 2019 connected at its distal end to the front handle 2017 and at its proximal end to a back handle 2020. A lock 2025 secures the back tube 2019 to the back handle 2020. The lumen 2008 is covered or surrounded by a reinforced tube or sheath 2022. The proximal end 2012 of the compound handle 2010 includes a lure connector 2023 that defines an opening that enables saline to enter the lumen 2008. In the enlarged view of the back or proximal handle portion 2014 of the compound handle 2010, the pressure sensor 2009 is again visible. Figure 2D

[0306] Referring again to Figure 2A , 2B ​, 2C and 2D, the device 2000 has the following dimensions: a length from the proximal end of the luer connection 2023 to the distal end 2006 of the needle 2005 is 1715 mm, a length from the distal end of the distal lock 2016 to the distal end 2006 of the needle 2005 is 1367 mm, a length from the proximal end of the distal lock 2016 to the distal end of the lock 2021 is 41 mm, a length from the distal end of the lock 2021 to the proximal end of the front handle 2017 is 71 mm, a length from the proximal end of the front handle 2017 to the distal end of the lock 2025 is 83 mm, a length from the distal end of the lock 2025 to the proximal end 2012 is 124 mm, a length from the distal end of the distal lock 2016 to the proximal end of the luer connection 2023 is 348 mm, a length from the proximal end of the distal lock 2016 to the proximal end of the front tube 2015 is 62.8 mm, an outer diameter of the sheath 2022 is 2.8 mm, an outer diameter of the front handle 2017 and the back handle 2020 is 19 mm, an inner diameter of the front tube 2015 and the back tube 2016 is 7.5 mm, and an outer diameter of the front tube 2015 and the back tube 2019 is 12.5 mm.

[0307] According to one aspect of the present specification, the needle ablation catheter and the needle of the device have a form factor that enables the needle to work with a traditional endoscope, i.e., the form factor enables the needle to slide through the working channel of the endoscope. Figure 3A and 3B A traditional endoscope 3060 is shown with a curved portion 3062 and a needle 3005 of a needle ablation catheter extending from a working channel 3061 of the endoscope 3060. In some embodiments, the curved portion 3062 has a curved length cl of 10 cm when curved, including a first distal length li of 4 cm, a second middle length l2 of 3 cm, and a third proximal length l3 of 3 cm. The distance dl between the distal and proximal ends of the curved portion 3062 is 5 cm when curved. As shown, the needle 3005 is able to bend or flex through an angle of at least 45 degrees. Figure 3A

[0308] According to embodiments of the present specification, Figure 4A , 4B A perspective view of the needle 4005 is shown, while Figure 4C a cross-sectional view of the needle 4005 is shown. According to one embodiment, the needle 4005 can be divided into a distal needle tip portion 4001, a middle portion 4002', and a proximal portion 4003'. Figure 4A , 4B and Figure 4C ​FIG. 40 is a longitudinal sectional view 4030 of the needle 4005 showing the tip portion 4001, the inner or middle conduit 4002, and the outer conduit 4003. According to one embodiment, the tip portion 4001 has a length of 80 mm (+ / - 60 mm) from the proximal end to the distal end of the tip portion 4001. The length of the needle 4005 from the proximal end of the middle portion 4002' to the distal end of the tip portion 4001 is 100 mm (+ / - 50 mm). The length of the proximal portion 4003' is 1650 mm.

[0309] Reference is now made to FIG. 40, Figure 4C FIG. 40 is a longitudinal sectional view 4030 of the needle 4005 showing the tip portion 4001, the inner or middle conduit 4002, and the outer conduit 4003. According to one embodiment, the tip portion 4001 has a length of 80 mm (+ / - 60 mm) from the proximal end to the distal end of the tip portion 4001. The length of the needle 4005 from the proximal end of the middle portion 4002' to the distal end of the tip portion 4001 is 100 mm (+ / - 50 mm). The length of the proximal portion 4003' is 1650 mm. Figure 4B According to embodiments of the present specification, the proximal portion 4003' houses or accommodates at least one flexible heating chamber 4028 (comprising a plurality of RF electrodes) located proximate to the proximal laser cut portion 4026 (the at least one flexible heating chamber 4028 is also shown in FIG. 41). Figure 4B During operation, saline enters from the proximal Figure 2B (2012) reaches the heating chamber 4028 where it is converted to vapor and exits through at least one port 4007 located at the distal end 4006 of the needle 4005.

[0310] As shown in the enlarged sectional view 4032, at the proximal end of the tapered portion 4027, the needle 4005 has an inner diameter of 1.76 mm and an outer diameter of 1.96 mm, while the inner conduit 4002 has an outer diameter of 2.6 mm and an inner diameter of 2 mm. In another embodiment, the inner conduit 4002 has an outer diameter of 2.7 mm and an inner diameter of 2.4 mm. At the distal end of the tapered portion 4027, the needle 4005 has an inner diameter of 0.9 mm. The portion 4027 has a taper or slope of 8.4 degrees relative to the horizontal axis from the proximal end to the distal end. The length of the tapered portion 4027 is 10 mm.

[0311] As shown in the enlarged sectional view 4035, at the tip portion 4001, the needle 4005 has an outer diameter of 1.1 mm and an inner diameter of 0.9 mm. As shown in the enlarged sectional view 4038, at the middle portion 4002', the needle 4005 has an inner diameter of 1.76 mm and an outer diameter of 1.96 mm, while the inner or middle conduit 4002 has an outer diameter of 2.6 mm. As shown in the enlarged sectional view 4040, at the proximal portion 4003', the needle 4005 still has an inner diameter of 1.76 mm and an outer diameter of 1.96 mm, the inner or middle conduit 4002 still has an outer diameter of 2.6 mm, while the outer conduit 4003 has an inner diameter of 2.9 mm and an outer diameter of 3.3 mm.

[0312] In some embodiments, the proximal portion 4003’ of the needle 4005 has an inner diameter greater than or equal to 1.5 mm (to accommodate the heating chamber 4028), while the tip portion 4001 has an outer diameter less than or equal to 1.1 mm to minimize leakage and infection. In some embodiments, the needle 4005 is electrically insulated and has no leaks along its length (see Figure 4D ) In various embodiments, the needle 4005 is sufficiently rigid at the tip and proximal portions 4001, 4003’ and has a flexible intermediate portion 4002’ of 10 to 20 cm to form a bend in an endoscope.

[0313] Figure 4D A cross-sectional view of a needle 4005 according to another embodiment of the present specification is shown. In this embodiment, the needle 4005 is covered or sheathed in an insulating coating 4042 that covers the proximal portion 4003’, the intermediate portion 4002’, and the tip portion 4001 up to a point proximal to at least one port 4007. In some embodiments, the insulating coating 4042 covers the entire needle 4005, in some embodiments, the needle 4005 comprises an inner catheter 8 cm portion of the distal end. In some embodiments, the needle 4005 has a diameter in the range of 12 Birmingham Gauge (G) and 30 G, and a length in the range of 1 cm to 10 cm. In some embodiments, the slope of the needle taper is defined in the range of 12 G / 1 cm to 30 G / 10 cm. The proximal portion 4003’ accommodates or houses at least one flexible heating chamber 4028 (comprising a plurality of electrodes) located proximal to the laser-cut portion 4026.

[0314] With reference to Figure 4D , in one embodiment, the needle 4005 has the following dimensions: a length from the distal end 4006 of the needle 4005 to the distal end of the intermediate portion 4002’ of 80 mm, a length from the distal end of the tapered portion 4027 to the proximal end of 8 mm, a length from the distal end of the laser-cut portion 4026 to the proximal end of the proximal portion 4003’ of 1712 mm, a total length from the proximal end of the proximal portion 4003’ to the distal end 4006 of the needle 4005 of 1800 mm (+ / - 30 mm), and the tapered portion 4027 has a taper or slope in the range of 1 to 20 degrees (or any increment therein) relative to a horizontal axis, preferably in the range of 3 to 10 degrees (or any increment therein), more preferably 6.2 degrees. At the tip portion 4001, the needle 4005 has an outer diameter of 1.1 mm and an inner diameter of 0.9 mm, while at the proximal portion 4003’, the needle 4005 has an inner diameter of 1.76 mm and an outer diameter of 1.96 mm.

[0315] Figure 4EPerspective views of various needles 4105, 4205, 4305 are shown according to embodiments of the present specification, showing needle tip portions 4101, 4201, 4301 and insulating coatings 4102, 4202, 4302. The needles 4105, 4205, 4305 are composed of a metal, such as but not limited to stainless steel, while the insulating coatings 4102, 4202, 4302 include PTFE, ePTFE, or silicone.

[0316] According to one aspect of the present specification, the needle of a needle ablation catheter is configured to have a variable stiffness over its length. As shown, a proximal portion 5003' of the needle 5005 has a first stiffness, an intermediate portion 5002' has a second stiffness, and a needle tip portion 5001 has a third stiffness. In some embodiments, the second stiffness is less than the first and third stiffnesses. In some embodiments, the first and third stiffnesses are approximately the same. In some embodiments, the first stiffness is greater than the third stiffness. In some embodiments, the first stiffness is less than the third stiffness. Figure 5A

[0317] Now referring to Figure 4C , in addition to Figure 5A and 5B , the intermediate portions 4002', 5002' include a laser cut portion 4026, which imparts a second stiffness to the intermediate portions 4002', 5002', thereby enabling the needles 4005, 5005 to bend at the portions 4002', 5002', while the relatively higher first and third stiffnesses allow the needle tip portions 4001, 5001 and the proximal portions 4003', 5003' to have sufficient rigidity. In some embodiments, the intermediate portions 4002', 5002' are configured to additionally include a tapered portion 4027. The tapered portion 4027 imparts further bendability and flexibility to the intermediate portions 4002', 5002'.

[0318] Figure 5B Various needles 5105, 5205, 5305 of needle ablation catheters having variable stiffnesses are shown according to some embodiments of the present specification. Each needle 5105, 5205, 5305 has a different laser cut pattern in an intermediate portion 5102', 5202', 5302', thereby imparting a different stiffness to each needle at that portion, and thus a different degree of flexibility. For example, in one embodiment, the needle 5105 has a laser cut intermediate portion 5102' such that the needle tip portion 5101 can bend relative to the proximal portion 5103' within a range 5115. The variable stiffness allows for bending of the intermediate portion and pushability along the catheter body.

[0319] Figure 5C Various laser cut patterns or designs are shown according to some embodiments of the present specification to impart variable levels of stiffness to different portions of various needles 5405, 5505. As shown,​Figure 5C As shown, in one embodiment, the middle portion 5402' of the needle 5405 is configured to have a generally helical or spiral laser cut 5445. The pitch of the cut 2045 varies along the length of the middle portion 5402' to impart a predetermined level of stiffness to enable the needle 5405 to bend along the middle portion 5402'. In another embodiment, the tip portion 5501 of the needle 5505 has a first laser cut design 5546 imparting a first level of stiffness to that region, the middle portion 5502' has a second laser cut design 5547 imparting a second level of stiffness to that region, and the proximal portion 5503' has a third laser cut design 5548 imparting a third level of stiffness to that region. In one embodiment, the first laser cut design 5546 causes less material of the needle 5505 to be removed in the tip portion 5501 compared to the second laser cut design 5547. As a result, the second level of stiffness is relatively less than the first level of stiffness. On the other hand, the third laser cut design 5548 can include no or substantially no material removal in the proximal portion 5503'. Thus, the third level of stiffness is greater than the first and second levels of stiffness.

[0320] Figure 5D Additional laser cut designs are shown to impart variable levels of stiffness to different portions of various needles in accordance with some embodiments of the present specification. The figure shows first, second, third, fourth, fifth, sixth, and seventh laser cut patterns 5050, 5051, 5052, 5053, 5054, 5055, 5056, respectively. For example, pattern 5056 is the most sparse and thus imparts the lowest level of stiffness. Patterns 5052, 5054, and 5055 are relatively denser in that they involve less needle material removal and thus correspond to higher levels of stiffness compared to pattern 5056.

[0321] While in some embodiments, the needle 4005 houses a heating chamber 4028, as shown, Figure 4C and 4D In some embodiments, the heating chamber is housed in a separate vapor delivery catheter rather than in the needle. Figure 6A and 6B A longitudinal cross-sectional view of a vapor delivery catheter 605 is shown, having a handle 610 at the proximal end, an expandable tip 615 at the distal end, and a lumen 620 extending from the proximal end to the distal end of the catheter 605. As shown, Figure 6B In some embodiments, the handle 610 is configured to lock onto an endoscope handle without significantly increasing the length of the resulting lever arm. Saline and electrical connections (for the heating chamber 628) enter the handle 610 from the proximal end.

[0322] Reference is now made to Figure 6A and 6Bat least one flexible heating chamber 628 (comprising a plurality of electrodes) is located within the lumen 620, proximal to the expandable tip 615. According to one embodiment, the outer diameter of the expandable tip 615 is smaller than the inner diameter of the lumen of the ablation needle (e.g., needle 4005 of Figure 4C and 4D needle 2005) such that the tip 615 can easily slide into the lumen of the needle. In some embodiments, the vapor delivery catheter 605 is located within the needle, which in turn is located within an outer catheter. In some embodiments, the inner diameter of the outer catheter is 3.5 mm, the outer diameter of the needle 2005 is 3.1 mm, and the outer diameter of the vapor delivery catheter 605 is 2.1 mm.

[0323] During operation, saline enters the catheter 605 through the proximal end and is converted to vapor, which enters the lumen of the needle through the expandable tip 615. In some embodiments, the catheter 605 includes a connector 607 for saline and electrical connectors for RF coil / heating chamber 628 current delivery in a port 606 for delivery of saline. The expandable tip 615 is heated by the flowing vapor and radially expands such that the outer diameter of the tip 615 expands to approximate the inner diameter of the lumen of the needle. This results in the space between the expanded tip 615 and the needle being occluded to form a seal and prevent backflow of vapor between the catheter 605 and the needle.

[0324] In some embodiments, the expandable tip 615 has an expandable metal coil covered by an insulating thermoplastic, such as but not limited to PTFE, ePTFE, and silicone. In some embodiments, the metal of the expandable metal coil is a shape memory metal that exhibits radial expansion due to a transition from a martensitic state to an austenitic state. In some embodiments, the metal of the expandable metal coil is a steel that exhibits radial expansion due to thermal expansion of the steel. Figure 6C and 6D First and second multiple expandable tip designs according to various embodiments of the present specification are shown. Figure 6C First, second, third, fourth, and fifth mesh or grid patterns 630, 631, 632, 633, 634 for the expandable tip 615 are shown, respectively. Figure 6D Sixth, seventh, eighth, and ninth mesh or grid patterns 635, 636, 637, 638 for the expandable tip 615 are shown, respectively.

[0325] Positioning element

[0326] Figures 7A-7EThe positioning elements in the above embodiments have been disclosed in the aforementioned related applications. However, in this case, the positioning elements have been modified such that when the pressure within the space enclosed by two or more positioning elements reaches or exceeds a predetermined threshold (e.g. 5 atmospheres), the positioning elements deform in a manner that, for example, bends one or more components (e.g. plates, disc portions, flaps, mesh weave) inwardly or outwardly from the plane that defines the original deployed shape to increase fluid flow from the interior of the enclosed space to the region outside the enclosed space. The deformation can be achieved by adding hinges, creases, grooves, more pliable materials, or other points of reduced material strength 51 between one or more components and the rest of the positioning element.

[0327] Figure 7A An ablation device with coaxial catheter design is shown in accordance with embodiments of the present specification. The coaxial design has a handle 52a, an infusion port 53a, an inner sheath 54a, and an outer sheath 55a. The outer sheath 55a is used to confine the positioning device 56a in the closed position and enclose the port 57a. Figure 7B A partially deployed positioning device 56b is shown, where the port 57b is still inside the outer sheath 55b. The positioning device 56b is partially deployed by pushing the catheter 54b out of the sheath 55b.

[0328] Figure 7C A fully deployed positioning device 56c is shown. The infusion port 57c is outside the sheath 55c. The length ‘l’ of the catheter 54c containing the infusion port 57c and the diameter ‘d’ of the positioning element 56c are predetermined / known and used to calculate the amount of thermal energy required. Figure 7D A conical design of the positioning element is shown. The positioning element 56d is conical in shape with a known length ‘l’ and diameter ‘d’ used to calculate the amount of thermal energy required for ablation. Figure 7E A disc design of the positioning element 56e including a circumferential ring 59e is shown. In some embodiments, the diameter of the positioning element 56e ranges from 5mm to 55mm. The positioning element 56e can be any circular shape and is not necessarily a perfect circle. The circumferential ring 59e is disposed at a fixed predetermined distance from the catheter 54e and is used to estimate the diameter of a hollow organ or hollow passage in the patient’s body.

[0329] Cover vapor delivery device

[0330] Figure 8AA positioning element or attachment 805 according to embodiments of the present specification is shown. The positioning element 805 is configured as a generally conical insulating sleeve that is attached near the tip 806 of the catheter 807. In some embodiments, the positioning element has a length and width of 0.5 cm and 5 cm, respectively. In alternative embodiments, the positioning element 805 has a different configuration, including but not limited to, square, rectangular, and parallelogram, for example. In one embodiment, the catheter 807 houses at least one flexible heating chamber 808 that includes a plurality of RF electrodes to convert saline entering the proximal end of the catheter 807 into steam.

[0331] Figure 8B A first set of exemplary dimensions of the positioning element 805 according to embodiments of the present specification is shown. The generally conical sleeve or positioning element 805 has a proximal end diameter dl of 2.4 mm, a distal end diameter d2 of 10 mm, and a length '1' of 10 mm. In various embodiments, the length '1' ranges from 0.1 mm to 10 cm, and the distal end diameter d2 ranges from 0.1 mm to 10 cm. In preferred embodiments, the length '1' and the distal end diameter d2 range from 5 mm to 5 cm.

[0332] Figure 8C and 8D A ball and socket attachment 815 according to embodiments of the present specification is shown for connecting the positioning element 805 to the tip 806 of the catheter 807. The tip 806 has a ball 810 and an anterograde or straight port 812 at its distal end. The positioning element 805 has a socket 816 at its proximal end. As shown, when the positioning element 805 is attached to the tip 806, the ball 810 is housed within the socket 815 to form the ball and socket attachment 815. Figure 8D

[0333] Reference is now made to Figure 8C and 8D ​, the ball-and-socket attachment 815 enables the positioning element 805 to move substantially relative to the tip 806. In some embodiments, the minimum range of movement of the positioning element 805 relative to the tip 806 is 90 degrees in any direction. Views 820, 822 show the positioning element 805 in a closed configuration, for example when the positioning element 805 and the tip 806 are located within an outer catheter. In some embodiments, the positioning element 805 is substantially cylindrical in the closed configuration with a diameter of 2.35 mm. Views 835, 837 show the positioning element 805 in an open or deployed configuration, for example when the positioning element 805 and the tip 806 are pushed out of the outer catheter. In some embodiments, the positioning element 805 obtains a substantially conical shape in the open or deployed configuration, with a base diameter of 12 mm and a side of 7 mm. In some embodiments, the positioning element 805 is a NiTi tube or mesh coated with PTFE, dPTFE or silicone. In some embodiments, a coating such as silicone covers part or all of the positioning element 805. In some embodiments, the silicone-coated positioning element 805 has one or more holes, each hole ranging from 10 microns to 1000 microns in diameter. The holes can allow air or vapor to escape from the chamber.

[0334] Figure 8E First and second perspective views 840, 842 and a longitudinal section view 845 of a positioning element 805 attached to a tip 806 of a catheter 807 are shown, in accordance with embodiments of the present specification. The catheter 807 is shown extending from an outer catheter 847 such that the positioning element 805 is in a deployed configuration, in which the positioning element 805 obtains a substantially conical configuration. The tip 806 includes a forward or straight facing port 812 at a distal end and / or two pairs of side ports 813 formed diametrically opposite on the sides of the tip 806 and positioned proximate to the distal end of the tip 806. In some embodiments, the port 812 has a diameter of 0.9 mm to allow passage of a guide wire, while the ports 813 have a diameter of 0.3 mm. In some embodiments, the catheter 807 has a length of 2500 mm from a proximal end of the catheter 807 to a distal end of the positioning element 805. In some embodiments, the outer catheter 847 has a length of 1800 mm (+ / - 50 mm) from a proximal end of the outer catheter 847 to a distal end.

[0335] Figure 8F Perspective and section views of a first configuration 850 of a positioning element 805 are shown, in accordance with embodiments of the present specification. The first configuration 850 includes a substantially cylindrical proximal portion 851f and a substantially conical distal portion 852f. In some embodiments, as shown in the perspective view 850a, the proximal portion 851f has a diameter of 2.35 mm and the distal portion 852f has a base diameter of 12 mm and a side of 7 mm. In some embodiments, the proximal portion 851f is coated with PTFE, dPTFE or silicone. In some embodiments, the distal portion 852f is coated with PTFE, dPTFE or silicone. Figure 8EAs shown, the generally cylindrical proximal portion 851f is attached to the tip 806, for example, by using glue. In the first configuration 850, the generally cylindrical proximal portion 851f has a diameter of 2.4 mm and a length of 3 mm, and the generally conical distal portion 852f has a base diameter of 10 mm (+ / - 1 mm), a length of 10 mm (+ / - 1 mm), and an apex angle or opening angle of 41.6 degrees. The total length of the proximal portion 851f and the distal portion 852f is 13 mm.

[0336] Figure 8G A perspective view and a cross-sectional view of a second configuration 855 of the positioning element 805 according to embodiments of the present specification is shown. The second configuration 855 includes a generally cylindrical proximal portion 851g and a generally conical distal portion 852g. In some embodiments, as shown, Figure 8E As shown, the generally cylindrical proximal portion 851g is connected to the tip 806, for example, by using glue. In the second configuration 855, the generally cylindrical proximal portion 851g has a diameter of 2.4 mm and a length of 5 mm, and the generally conical distal portion 852g has a base diameter of 15 mm (+ / - 2 mm), a length of 15 mm (+ / - 1 mm), and an apex angle or opening angle of 45.6 degrees. The total length of the proximal portion 851g and the distal portion 852g is 20 mm.

[0337] Figure 8H A perspective view and a cross-sectional view of a third configuration 860 of the positioning element 805 according to embodiments of the present specification is shown. The third configuration 860 includes a generally cylindrical proximal portion 851h and a generally conical distal portion 852h. In some embodiments, as shown, Figure 8E As shown, the generally cylindrical proximal portion 851h is connected to the tip 806, for example, by using glue. In the third configuration 860, the generally cylindrical proximal portion 851h has a diameter of 2.4 mm, and the generally conical distal portion 852h has a base diameter of 20 mm (+ / - 2 mm), a length of 20 mm (+ / - 2 mm), and an apex angle or opening angle of 47.5 degrees. The total length of the proximal portion 851h and the distal portion 852h is 25 mm.

[0338] Figure 8I A perspective view and a cross-sectional view of a fourth configuration 865 of the positioning element 805 according to embodiments of the present specification is shown. The fourth configuration 865 includes a generally cylindrical proximal portion 851i, a generally conical middle portion 852i, and a generally pyramidal distal portion 853i. The generally pyramidal distal portion 853i is connected to the generally conical middle portion 852i as a base. In alternative embodiments, the entire positioning element 805 is generally pyramidal in shape.

[0339] In some embodiments, as shown, Figure 8EThe generally cylindrical proximal portion 851i is attached to the tip 806, for example by using glue. In the fourth configuration 865, the generally cylindrical proximal portion 851i has a diameter of 2.4 mm and a length of 5 mm, the generally conical middle portion 852i has a length of 10 mm (+ / - 2 mm) and an apex or opening angle of 41.6 degrees, and the generally pyramidal distal portion 853i has a square base with each side of 15 mm (+ / - 2 mm). The total length of the middle portion 852i and the distal portion 853i is 15 mm (+ / - 2 mm). The total length of the proximal portion 851i, the middle portion 852i, and the distal portion 853i is 20 mm (+ / - 2 mm). Although Figures 8A-8I Positioning elements or attachments having other three-dimensional polygonal or curved shapes are possible in other embodiments.

[0340] In various embodiments, the positioning element is mechanically compressed to enter the endoscope channel or outer catheter, and expands when deployed or extended.

[0341] In some embodiments, the positioning element 805 comprises a shape memory alloy, such as Nitinol, allowing it to transform from a compressed configuration for delivery through an endoscope to an expanded configuration for treatment. In some embodiments, the compressed configuration approximates a cylinder to be able to pass through the lumen of an endoscope, attach to the distal end of a catheter, and have a diameter of 5 mm and a length in the range of 0.5 cm to 5 cm. Upon expansion, the positioning element 805 has a length in the range of 1 cm to 10 cm, a diameter of 1 cm, and a surface area (from which vapor is expelled) in the range of 1.5 cm 2 to 6.25 cm 2 In one preferred embodiment, the surface area is a square of 1.5 cm by 1.5 cm. Upon expansion, the length is slightly shorter, so the expanded configuration has a shorter length than the compressed configuration. In one embodiment, the use of an ablation catheter with the positioning element 805 creates a seal, forming an ablation region with a radius of 1 cm, a length of 1 cm, a surface area of 6.28 cm 2 , and a treatment space of 3.14 cm 3 .

[0342] Referring to FIGS. 1-4 Figures 7A-7EIn various embodiments of the positioning elements described in the context of FIGS. 8A through 8I, in some embodiments, for gastrointestinal (GI) region applications, the steam delivery time ranges from 1 second to 20 seconds. The duration during which the mucosal temperature > 60°C but < 110°C is from 1 second to 10 seconds. After a shut-off time > 1 second and < 30 minutes, multiple treatment sessions can be repeated. The duration of each treatment session can be the same or different. In one embodiment, the durations of two or more treatment sessions are the same, and in another embodiment, the duration of the first treatment session is less than the duration of the second treatment session. In yet another embodiment, the duration of the first treatment session is greater than the duration of the second treatment session.

[0343] In various embodiments, multiple treatment sessions with variable time / dose are applied. In some embodiments, each treatment session is defined by a treatment time (T1) and a dose (D1). In one embodiment, the first treatment session delivers for a time < T1 at dose T1. Then, the doctor waits for a time of 1 second to 30 minutes for a certain degree of edema to form, and then delivers for 1 second at a dose ranging from 1×T1 to 5×T1. After the steam is turned off, negative pressure is applied to the ablation area in the form of suction or vacuum to increase blood flow to cool the tissue. This increase in blood flow also increases the formation of edema.

[0344] Figure 8J An ablation catheter 870 is shown in accordance with some embodiments of the present specification, having at least one tapered attachment or positioning element 872 and an electrode heating chamber 874. In various embodiments, the attachment or positioning element 872 is similar to those Figures 8A-8I described. The attachment or positioning element 872 is positioned at the distal end of the catheter 870, and at least one port 876 is positioned at the distal end of the catheter such that once the catheter 870 is deployed, the port delivers steam into the space surrounded by the attachment or positioning element. In some embodiments, the distal end 871 of the catheter 870 includes at least one port 876 and at least one positioning element 872 attached to the distal end 871 such that in an operative configuration, at least one positioning element 872 surrounds at least one port 876 and is configured to direct all the steam discharged from at least one port 876. In some embodiments, the attachment or positioning element 872 is made of shape memory metal and can be transformed from a first compressed configuration for delivery through the lumen of an endoscope to a second expanded configuration for treatment. The electrode heating chamber 874 is located within the lumen of the catheter body 878 and, in some embodiments, is within a range of 1 mm to 50 cm from the delivery port 876. In some embodiments, the catheter 870 includes a filter 880 having micropores that provides backpressure to the delivered steam, thereby pressurizing the steam. The predetermined size of the micropores in the filter determines the backpressure and thus the temperature of the generated steam.

[0345] Figure 9A is a flowchart illustrating a method of ablating tissue within a patient's gastrointestinal tract according to other embodiments of the present specification. In some embodiments, Figure 9A the method of is shown to perform localized ablation after observing the patient following circumferential focused ablation to treat any remaining precancerous or cancerous tissue in the esophagus, duodenum, bile duct, and pancreas. In some embodiments, an ablation catheter disclosed in the present specification, such as Figure 8J ablation catheter 870 of is used to perform the ablation method of Figure 9A at 902, an ablation catheter configured for a gastrointestinal (GI) tract is inserted into a patient's gastrointestinal tract. At 904, a seal is formed between an outer surface of the ablation catheter and an inner wall of the gastrointestinal tract, forming a treatment space. The seal is created by expansion of an attachment or positioning element of the ablation catheter, as explained in embodiments of the present specification. In some embodiments, the seal is temperature dependent and the seal is broken when a temperature within the sealed portion or treatment space exceeds a particular temperature. In one embodiment, the particular temperature is 90 °C. In some embodiments, the seal is pressure dependent and the seal is broken when a pressure within the sealed portion or treatment space exceeds a particular pressure. In one embodiment, the particular pressure is 5 atmospheres. At 906, steam is delivered through the ablation catheter into the sealed portion of the gastrointestinal tract while the seal is still in effect. At 908, the steam condenses on the treated tissue, thereby ablating the tissue.

[0346] Figure 9B is a flowchart illustrating a method of ablating tissue within a patient's gastrointestinal tract according to other embodiments of the present specification. In some embodiments, Figure 9B the method of is shown to perform localized ablation after observing the patient following circumferential focused ablation to treat any remaining precancerous or cancerous tissue in the esophagus, duodenum, bile duct, and pancreas. In some embodiments, an ablation catheter disclosed in the present specification, such as Figure 8J ablation catheter 870 of is used to perform the ablation method of Figure 9B at 912, an ablation catheter configured for a gastrointestinal (GI) tract is inserted into a patient's gastrointestinal tract. At 914, saline with variable flow is introduced into the gastrointestinal tract through the ablation catheter. At 916, the saline is heated using RF energy to create steam that passes through the ablation catheter into the gastrointestinal tract. In some embodiments, the flow of saline during steam delivery is different than the flow of saline during phases without treatment delivery. In some embodiments, the flow of saline during treatment is lower than the flow of saline during non-treatment. In some embodiments, the flow of saline during treatment is lower than the flow of saline during non-treatment. At 918, the steam condenses on the treated tissue, thereby ablating the tissue.

[0347] Figure 9Cis a flowchart showing a method of performing circumferential ablation using a first ablation catheter followed by focal ablation using a second ablation catheter, in accordance with some embodiments of the present specification. It should be noted that alternatively, in other embodiments, the first stage circumferential ablation using the first ablation catheter is followed (either immediately or later) by a second stage circumferential ablation using the same first ablation catheter, rather than focal ablation using a second ablation catheter. Figure 9C The method of the present specification includes a two-step or two-stage process to ensure full or near-full ablation of the target tissue. In some embodiments, in the first stage, a patient is treated with a first ablation catheter having two positioning elements to perform circumferential ablation. In some embodiments, the first ablation catheter having two positioning elements for the first stage is similar to the ablation catheter 1991 of the present specification. Figure 1K The method of the present specification includes a two-step or two-stage process to ensure full or near-full ablation of the target tissue. In some embodiments, in the first stage, a patient is treated with a first ablation catheter having two positioning elements to perform circumferential ablation. In some embodiments, the first ablation catheter having two positioning elements for the first stage is similar to the ablation catheter 1991 of the present specification.

[0348] After performing ablation using the first ablation catheter having two positioning elements, in step 934, the physician inspects the ablation area. In observing the patient, the physician can identify a tissue mass that requires focal ablation. A second stage is then performed in which a second ablation catheter having a needle or cap, shield or disc attachment or positioning element at the distal end is used for focal ablation. The second stage can be performed immediately after the first stage or later. In some embodiments, the second ablation catheter having a needle or cap, shield or disc attachment or positioning element at the distal end for the second stage is similar to the ablation catheter 1992 of the present specification. Figure 8Jthe first ablation catheter. (Or, in other embodiments, the physician can wait a period of time ranging from six weeks to two years, measure the efficacy of the first stage, and then perform a second stage using the same first ablation catheter for another round of circumferential ablation. At step 936, a second ablation catheter with a distal tip accessory or positioning element is inserted into the patient's gastrointestinal tract through the lumen of the endoscope. At step 938, the distal tip accessory or positioning element is expanded to form a second seal between the periphery of the distal tip accessory or positioning element and the gastrointestinal tract, and a second enclosed treatment space between the distal tip accessory or positioning element and the surface of the patient's gastrointestinal tract. At step 940, steam is delivered into the second enclosed treatment space through at least one port located at the distal tip of the catheter. In some embodiments, the system includes a foot pedal in data communication with a controller for controlling the catheter, a switch on the catheter, or a switch on the controller, for controlling the flow of steam, and step 940 is implemented using the foot pedal in data communication with the controller, the switch on the catheter, or the switch on the controller. At step 942, the steam condenses on the tissue within the second enclosed treatment space to concentrate ablation of the tissue. Then, at step 944, the second ablation catheter with the distal tip accessory or positioning element is removed from the gastrointestinal tract.

[0349] Figure 9Dis a multi-stage method flowchart showing duodenal ablation using a steam ablation system to treat obesity, overweight, eating disorders, metabolic syndrome, diabetes, dyslipidemia, nonalcoholic steatohepatitis (NASH), nonalcoholic fatty liver disease (NAFLD), or polycystic ovary disease, according to embodiments of the present specification. In step 952, the patient is first screened to determine if the patient is a candidate for duodenal ablation using the ablation system of the present specification. For diabetes, metabolic syndrome, obesity, or overweight, in various embodiments, the patient must have a BMI (Body Mass Index) of 25 or higher (overweight 25-30, obesity 30 or higher, morbid obesity 35 and above). According to various aspects of the present specification, the patient with diabetes must have an HbAlc level of at least 6.5 gm%, a fasting blood glucose level of at least 126 mg / dL or a random plasma glucose level of at least 200 mg / dL, a 2-hour plasma glucose level of at least 200 mg / dL (11.1 mmol / L) during an oral glucose tolerance test (OGTT), or a fasting insulin concentration of at least 5.7 μU / mL (109 pmol / L). For insulin resistance, in various embodiments, the patient must have an insulin resistance homeostatic model assessment (HOMA-IR) of at least 1.6. According to various aspects of the present specification, the patient with dyslipidemia must have a serum triglyceride concentration of at least 130 mg / dL (1.47 mmol / L) or a ratio of triglyceride to HDL (HDL) cholesterol concentration greater than 3.0 (1.8 SI units).

[0350] According to embodiments of the present specification, the patient screened and determined to be a duodenal ablation candidate at step 952 subsequently undergoes an ablation procedure using a vapor ablation system. The vapor ablation system is configured to perform circumferential ablation of the patient’s duodenum or small intestine to treat any one or more of the conditions described above. The vapor ablation system includes a controller having at least one processor in data communication with at least one pump and a catheter connection port in fluid communication with the at least one pump. At step 954 of the first treatment phase, a proximal end of a first catheter is connected to the catheter connection port to place the first catheter in fluid communication with the at least one pump. The first catheter includes at least two positioning elements separated along a length of the catheter and at least two ports located between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein in the first configuration each of the at least two positioning elements is compressed within the catheter and in the second configuration each of the at least two positioning elements is expanded to at least partially outside of the catheter. At step 956, the first catheter is positioned within the patient such that upon expansion into the second configuration, a distal of the at least two positioning elements is positioned within the patient’s small intestine and a proximal of the at least two positioning elements is positioned more than 1 cm from the distal of the at least two positioning elements. Then, at step 958, each of the at least two positioning elements is expanded into their second configuration. At step 960, the controller is activated, wherein upon activation the controller is configured to cause the at least one pump to deliver saline into the at least one lumen of the first catheter, and wherein upon activation the controller is configured to cause an electrical current to be delivered to the at least one electrode located in the at least one lumen of the first catheter. The electrical current causes the electrode to heat and the contact of the saline with the heated electrode converts the saline to vapor, which is delivered through the at least two ports to circumferentially ablate the target tissue.

[0351] In various embodiments, the vapor is delivered to treat at least 1-15 cm of contiguous or non-contiguous small intestinal mucosa. In various embodiments, the vapor is delivered to treat at least 50% of the circumference of the small intestine. In various embodiments, the vapor dose is characterized by at least one of: the vapor dose has an energy of 5-25 J / cm 2 is delivered over 1-60 seconds at an energy rate of 5-2500 calories / second; the vapor dose is delivered such that the total dose is 5-40 calories / gram of tissue to be ablated; the vapor dose is delivered to raise the temperature of the target tissue to above 60°C but below 110°C, the vapor temperature is 99°C to 110°C; or the vapor dose is delivered such that the pressure in the small intestine is less than 5 atmospheres, preferably less than 1 atmosphere.

[0352] At step 962, the controller cuts off the delivery of saline and electrical current after a period of 1 to 60 seconds. In some embodiments, the controller automatically cuts off the delivery of saline and electrical current. At step 964, the controller is repeatedly activated to deliver saline into the lumen and to deliver electrical current to the at least one electrode until the procedure is terminated by the physician. In some embodiments, the system further comprises a foot pedal, a switch on the catheter, or a switch on the controller in data communication with the controller for controlling the steam flow, and step 964 is implemented using the foot pedal, the switch on the catheter, or the switch on the controller in data communication with the controller. At step 966, the first catheter is removed from the patient to complete the first treatment phase.

[0353] At step 968, the physician then waits at least six weeks after the completion of the first phase to allow the ablation therapy to take effect before evaluating the treatment effectiveness. After the at least six weeks, at step 970, a post-phase one evaluation is performed in which the efficacy of the first treatment phase is determined by measuring a physiological parameter related to the condition being treated and comparing the measurement to a desired treatment goal or endpoint.

[0354] In various embodiments, a patient having obesity, overweight, a diet disorder, dyslipidemia, or diabetes is provided with an ablation treatment to achieve the following treatment goals or endpoints, and the first treatment phase for these patients is considered successful if any one or more of the following treatment goals or endpoints are achieved: a total body weight of the patient is reduced by at least 1% relative to the total body weight of the patient prior to ablation; an overweight body weight of the patient is reduced by at least 1% relative to the overweight body weight of the patient prior to ablation; a total body weight of the patient is reduced by at least 1% relative to the total body weight of the patient prior to ablation and a health level of the patient is reduced by no more than 5% relative to the health level of the patient prior to ablation; an overweight body weight of the patient is reduced by at least 1% relative to the overweight body weight of the patient prior to ablation and a health level of the patient is reduced by no more than 5% relative to the health level of the patient prior to ablation; a pre-meal ghrelin level of the patient is reduced by at least 1% relative to the pre-meal ghrelin level of the patient prior to ablation; a post-meal ghrelin level of the patient is reduced by at least 1% relative to the post-meal ghrelin level of the patient prior to ablation; an exercise output of the patient is increased by at least 1% relative to the exercise output of the patient prior to ablation; a glucagon-like peptide-1 level of the patient is increased by at least 1% relative to the glucagon-like peptide-1 level of the patient prior to ablation; a leptin level of the patient is increased by at least 1% relative to the leptin level of the patient prior to ablation; an appetite of the patient is reduced over a predetermined period of time relative to the appetite of the patient prior to ablation; a peptide YY level of the patient is increased by at least 1% relative to the peptide YY level of the patient prior to ablation; a lipopolysaccharide level of the patient is reduced by at least 1% relative to the lipopolysaccharide level of the patient prior to ablation; a motilin-related peptide level of the patient is reduced by at least 1% relative to the motilin-related peptide level of the patient prior to ablation; a cholecystokinin level of the patient is increased by at least 1% relative to the cholecystokinin level of the patient prior to ablation; a resting metabolic rate of the patient is increased by at least 1% relative to the resting metabolic rate of the patient prior to ablation; a plasma beta-endorphin level of the patient is increased by at least 1% relative to the plasma beta-endorphin level of the patient prior to ablation; an HbAlc level of the patient is reduced by at least 0.3% relative to the HbAlc level of the patient prior to ablation; a triglyceride level of the patient is reduced by at least 1% relative to the triglyceride level of the patient prior to ablation; a total blood cholesterol level of the patient is reduced by at least 1% relative to the total blood cholesterol level of the patient prior to ablation; a blood glucose level of the patient is reduced by at least 1% relative to the blood glucose level of the patient prior to ablation; a composition of the gut microbiota of the human is modulated from a first state prior to ablation to a second state after ablation, wherein the first state has a first level of Bacteroidetes and a first level of Firmicutes, wherein the second state has a second level of Bacteroidetes and a second level of Firmicutes, wherein the second level of Bacteroidetes is at least 3% greater than the first level of Bacteroidetes, and wherein the second level of Firmicutes is at least 3% less than the first level of Firmicutes; or, a cumulative daily dose of an anti-diabetic drug of the patient is reduced by at least 10% relative to the cumulative daily dose of the anti-diabetic drug of the patient prior to ablation.

[0355] In various embodiments, ablation therapy is provided to achieve the following treatment goals or endpoints for dyslipidemia patients, and the first treatment phase is considered successful for these patients if any one or more of the following treatment goals or endpoints are achieved: the patient's lipid profile is improved by at least 10% relative to the patient's lipid profile prior to ablation, where the lipid profile is defined at least by the ratio of LDL cholesterol to HDL cholesterol, and improvement is defined as a decrease in the ratio of LDL cholesterol to HDL cholesterol; the patient's LDL cholesterol level is reduced by at least 10% relative to the patient's LDL cholesterol level prior to ablation; or, the patient's VLDL cholesterol level is reduced by at least 10% relative to the patient's VLDL cholesterol level prior to ablation.

[0356] In various embodiments, ablation therapy is provided to achieve the following treatment goals or endpoints for patients with nonalcoholic steatohepatitis (NASH) or nonalcoholic fatty liver disease (NAFLD), and a first treatment phase is considered successful for these patients if any one or more of the following treatment goals or endpoints are achieved: at least 10% reduction in ALT or AST levels relative to pre-ablation ALT or AST levels; at least 10% improvement in serum ferritin levels or an absolute serum ferritin level below 1.5ULN (upper limit of normal); at least 5% improvement in hepatic steatosis (HS) relative to the level of HS prior to ablation, or HS less than 5% by liver biopsy; at least 5% improvement in HS relative to the level of HS prior to ablation, or HS less than 5% by magnetic resonance (MR) imaging (by spectroscopy or proton density fat fraction); at least 5% improvement in the NAFLD fibrosis score (NFS) relative to the NFS score prior to ablation; at least 5% improvement in the non-NAFLD activity score (NAS) relative to the NAS prior to ablation; at least 5% improvement in the steatosis-activity fibrosis (SAF) score relative to the SAF score prior to ablation; at least 5% reduction in the average annual fibrosis progression rate relative to the average annual fibrosis progression rate prior to ablation, as measured by histology, the Fibrosis-4 (FIB-4) index, the aspartate aminotransferase-to-platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) panel, FibroTest, Fibrosure, or Hepascore), or imaging (transient elastography (TE), MR elastography (MRE), acoustic radiation force impulse imaging, or ultrasound shear wave elastography); at least 5% reduction in the circulating levels of cytokeratin-18 fragment relative to the circulating levels of cytokeratin-18 fragment prior to ablation; at least 5% improvement in the FIB-4 index, the aspartate aminotransferase-to-platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) panel, FibroTest, Fibrosure, or Hepascore), or imaging (transient elastography (TE), MR elastography (MRE), acoustic radiation force impulse imaging, or ultrasound shear wave elastography) relative to the FIB-4 index, the aspartate aminotransferase-to-platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) panel, FibroTest, Fibrosure, or Hepascore), or imaging (transient elastography (TE), MR elastography (MRE), acoustic radiation force impulse imaging, or ultrasound shear wave elastography) prior to ablation; at least 5% reduction in liver stiffness relative to the liver stiffness prior to ablation, as measured by vibration-controlled transient elastography (VCTE / fibroscan); at least 2-point improvement in the NAS, at least 1 -point improvement in hepatocellular ballooning, at least 1 -point improvement in lobular inflammation or steatosis score, and no increase in fibrosis score relative to the NAS, hepatocellular ballooning, lobular inflammation, steatosis, and fibrosis scores prior to ablation; at least 5% improvement in the NFS score relative to the NFS score prior to ablation; or at least 5% improvement in any of the NAFLD parameters above compared to sham intervention or placebo.

[0357] If any of the above treatment goals or endpoints are met, treatment is completed at step 972, and no further ablation is performed. If the above treatment goals or endpoints are not met, the entire ablation procedure and assessment (minus the screening procedure but including steps 954-970) is repeated for a second treatment session, and if the treatment goals or endpoints are still not met, repeated for a subsequent treatment session, with at least a 6-week wait between each ablation procedure and each assessment.

[0358] Figure 9E is a flowchart illustrating a multi-stage method of treating cancerous or precancerous esophageal tissue using a vapor ablation system in accordance with various embodiments of the present specification. The vapor ablation system includes a controller having at least one processor in data communication with at least one pump and a catheter connection port in fluid communication with the at least one pump. At step 953, a proximal end of a first catheter is connected to the catheter connection port to place the first catheter in fluid communication with the at least one pump, wherein the first catheter includes at least two positioning elements separated along a length of the catheter and at least two ports located between the at least two positioning elements, wherein each of the at least two positioning elements has a first configuration and a second configuration, and wherein, in the first configuration, each of the at least two positioning elements is compressed within the catheter and, in the second configuration, each of the at least two positioning elements is expanded to be at least partially outside the catheter. At step 955, the first catheter is positioned within a patient such that, when expanded into the second configuration, a distal positioning element of the at least two positioning elements is positioned in proximity to the patient’s esophagus and a proximal positioning element of the at least two positioning elements is positioned more than 1 cm away from the distal positioning element of the at least two positioning elements. At step 957, each of the at least two positioning elements is expanded into their second configuration. At step 959, the controller is activated, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into at least one lumen in the first catheter, and wherein, upon activation, the controller is configured to cause an electrical current to be delivered to at least one electrode located in the at least one lumen of the first catheter. The electrical current causes the electrode to heat, and contact of the saline with the heated electrode converts the saline to vapor, which is delivered through the at least two ports to circumferentially ablate the target tissue. In some embodiments, the at least two positioning elements define a first enclosed space with the esophageal tissue, wherein at least one of the at least two positioning elements is positioned relative to the esophageal tissue to allow air to flow out of a second enclosed space when vapor is delivered.

[0359] In various embodiments, the vapor is delivered to treat at least 1-15 cm of contiguous or non-contiguous small intestinal mucosa. In various embodiments, the vapor is delivered to treat at least 50% of the circumference of the small intestine. In various embodiments, the vapor dose is characterized by at least one of: the energy of the vapor dose is 5-25 J / cm 2; the vapor dose is delivered over 1-60 seconds; the vapor dose is delivered at an energy rate of 5-2500 calories / second; the vapor dose is delivered such that the total dose is 5-40 calories / gram of tissue to be ablated; the vapor dose is delivered to raise the temperature of the target tissue to above 60°C but below 110°C, with a vapor temperature between 99°C and 110°C; or the vapor dose is delivered such that the pressure in the small intestine is less than 5 atmospheres, preferably less than 1 atmosphere.

[0360] In various embodiments, the vapor is delivered to treat at least 1-15 cm of contiguous or non-contiguous small intestine mucosa. In various embodiments, the vapor is delivered to treat at least 50% of the circumference of the small intestine. In various embodiments, the vapor dose is characterized by at least one of: the energy of the vapor dose is 5-25 J / cm 2 ; the vapor dose is delivered over 1-60 seconds; the vapor dose is delivered at an energy rate of 5-2500 calories / second; the vapor dose is delivered such that the total dose is 5-40 calories / gram of tissue to be ablated; the vapor dose is delivered to raise the temperature of the target tissue to above 60°C but below 110°C, with a vapor temperature between 99°C and 110°C; or the vapor dose is delivered such that the pressure in the small intestine is less than 5 atmospheres, preferably less than 1 atmosphere.

[0361] At step 961, the controller cuts off the delivery of saline and current. In some embodiments, the controller automatically cuts off the delivery of saline and current. Optionally, at step 963, the controller is reactivated to deliver saline into the lumen of the first catheter and to deliver current to the electrode until the procedure is terminated by the physician. At step 965, the catheter is removed from the patient to complete the first treatment phase.

[0362] At step 967, the physician waits at least six weeks before assessing the efficacy of the first phase. After at least six weeks, at step 969, a post-phase one assessment is performed, in which the efficacy of the first treatment phase is determined by measuring a physiological parameter related to the condition being treated and comparing the measurement to a desired treatment goal or endpoint. (Alternatively, in other embodiments, a visual assessment is performed immediately after the first phase is completed, and if deemed necessary based on visual observation, a second treatment phase using a second catheter is performed prior to waiting at least six weeks).

[0363] If the intended therapeutic goal or endpoint has not been achieved, a second phase of treatment is performed. At step 971, the proximal end of a second catheter is connected to the catheter connection port to place the second catheter in fluid communication with the at least one pump, wherein the second catheter comprises a distal end having at least one port and at least one positioning element attached to the distal end, such that in the operative configuration, the at least one positioning element surrounds the at least one port and is configured to direct all vapor expelled from the at least one port. At step 973, the second catheter is positioned within the patient such that a distal surface of the at least one positioning element is positioned in the vicinity of the patient’s esophagus. Optionally, the at least one positioning element is expandable from a first collapsed configuration to an expanded operative configuration, and at step 975, the at least one positioning element is expanded to the operative configuration. At step 977, the controller is activated, wherein, upon activation, the controller is configured to cause the at least one pump to deliver saline into the at least one lumen of the second catheter, and wherein, upon activation, the controller is configured to cause electrical current to be delivered to the at least one electrode located in the at least one lumen of the second catheter. The electrical current causes the electrode to heat, and contact of the saline with the heated electrode converts the saline to vapor, which is delivered through the at least one port to concentrate ablation of the target tissue. In some embodiments, during the second phase of treatment, the at least one positioning element defines a second enclosed space with the esophageal tissue, wherein the at least one positioning element is positioned relative to the esophageal tissue to allow air to flow out of the second enclosed space when vapor is delivered.

[0364] In various embodiments, the vapor is delivered to treat at least 1-15 cm of contiguous or non-contiguous small intestine mucosa. In various embodiments, the vapor is delivered to treat at least 50% of the circumference of the small intestine. In various embodiments, the vapor dose is characterized by at least one of: a vapor dose energy of 5-25 J / cm2delivered in 1-60 seconds; a vapor dose delivered at an energy rate of 5-2500 calories / second; a vapor dose delivered such that the total dose is 5-40 calories / gram of tissue to be ablated; a vapor dose delivered to raise the temperature of the target tissue to above 60°C but below 110°C, a vapor temperature between 99°C and 110°C; or a vapor dose delivered such that the pressure in the small intestine is less than 5 atmospheres, preferably less than 1 atmosphere.

[0365] At step 979, the controller turns off the delivery of saline and electrical current after a period of 1 to 60 seconds. In some embodiments, the controller automatically turns off the delivery of saline and electrical current. Alternatively, in some embodiments, the controller is repeatedly activated at step 981 to deliver saline into the lumen and electrical current to the at least one electrode until the procedure is terminated by the physician. In some embodiments, the system further comprises a foot pedal, a switch on the catheter, or a switch on the controller in data communication with the controller for controlling the steam flow, and step 981 is achieved by using the foot pedal, the switch on the catheter, or the switch on the controller in data communication with the controller. At step 983, the second catheter is removed from the patient to complete the second treatment phase. In some embodiments, an evaluation is performed at least six weeks to two years after the completion of the second phase to determine the efficacy of the second phase, and further first and / or second phases and further evaluations can be performed as needed if the desired treatment goals or endpoints are not achieved.

[0366] Treatment pressure profile for ablation therapy

[0367] In various embodiments, the catheters of the present specification measure and monitor the pressure of the steam throughout the ablation treatment and keep the pressure below a predetermined limit, for example 5 atmospheres or 5 psi, to limit the amount of heat energy delivered to the tissue during treatment.

[0368] According to one aspect of the present specification, the energy consumed by the heating chamber reflects the steam pressure generated. Figure 10A First and second graphs are shown according to embodiments of the present specification, which show the energy consumption curve of the heating chamber (flexible heating chamber, with RF electrode or induction coil based heating chamber) and the pressure curve of the steam generated during the ablation treatment. The first graph 1005 shows the power or energy consumption of the heating chamber (in units of Watts) versus time, while the second graph 1007 shows the steam pressure at the heating chamber entry port versus time. As shown, when the steam pressure reaches above a predetermined limit, for example 5 psi, the ablation treatment is stopped and an alarm 1008 is generated. Figure 10B

[0369] According to another aspect of the present specification, the temperature of the steam is related to the steam pressure measured along the steam path. Figure 10C Third and fourth graphs are shown according to embodiments of the present specification, which show the temperature profile of the steam generated during the ablation treatment and the pressure profile of the steam. The third graph 1010 shows the temperature profile of the steam versus time, while the fourth graph 1012 shows the pressure profile of the steam versus time along the steam path.

[0370] Figures 10D-10P ​Exemplary vapor pressure-based treatment profiles during ablation are shown in accordance with embodiments of the present specification. The pressure treatment profiles in each graph are shown as a graph with time in seconds on the X-axis and pressure in atmospheres on the Y-axis.

[0371] Figure 10D A pressure treatment profile 1015 is shown in which vapor delivery begins, the pressure rises to a desired maximum pressure 1017, for example 3 atmospheres. The vapor pressure is held at the maximum pressure 1017 for a predetermined time, for example 10 seconds, then vapor delivery stops, allowing the pressure to return to baseline 1018.

[0372] Figure 10E A pressure treatment profile 1015 is shown repeated for multiple cycles in which the desired maximum pressure 1017 is the same for each cycle. Figure 10F A pressure treatment profile 1015 is shown repeated for multiple cycles in which the desired maximum pressure 1017 is customized for each cycle. For example, the desired maximum pressure 1017 is: 2 atmospheres for a first cycle 1020a, 2.5 atmospheres for a second cycle 1020b, and 3 atmospheres for a third cycle 1020c. Thereafter, the desired maximum pressure 1017 is: 3 atmospheres for a fourth cycle 1020d, 2.5 atmospheres for a fifth cycle 1020e, and 2 atmospheres for a sixth cycle 1020f. In other words, the desired maximum pressure 1017 is increased and decreased for each cycle 1020a-f by increasing and decreasing vapor flow to create a customized treatment profile.

[0373] Figure 10G 10H And 10I A pressure treatment profile 1025, 1026, and 1027 is shown in which the pressure of vapor delivery is gradually increased to reach a target pressure 1028, at which point vapor delivery is discontinued, allowing the pressure to return to baseline pressure 1029. Figure 10J A plurality of cycles of at least one of the pressure treatment profiles 1025, 1026, and 1027 is shown in which for each cycle, the treatment pressure is accumulated to a desired target pressure 1028, then stopped to return to baseline pressure 1029 and cycle.

[0374] Figure 10K A pressure treatment profile 1030 is shown in which the pressure of vapor delivery is rapidly increased to reach a target pressure 1032 for a predetermined period of time, after which vapor delivery is gradually decreased to allow the pressure to slowly return to baseline pressure 1034.

[0375] Figure 10L ​A number of cycles of a pair of first and second pressure profiles 1035, 1037 are shown, where the first pressure profile 1035 has a first maximum pressure 1036 and the second pressure profile 1037 has a second maximum pressure 1038. In some embodiments, the first maximum pressure 1036 is higher than the second maximum pressure 1038. Thus, a higher steam delivery pressure is cycled with a lower steam delivery pressure.

[0376] Figure 10M A number of cycles of a pressure profile 1040 are shown, where for each cycle, steam is delivered to a pressure Pi for a predetermined duration. Next, steam delivery is discontinued and the pressure is allowed to decrease to a pressure P2 below a baseline 1042 for another predetermined duration. Thereafter, steam delivery is resumed and delivered to a pressure P3 for yet another predetermined duration. Finally, steam delivery is discontinued and the pressure is allowed to return to the baseline pressure 1042. In some embodiments, the pressure Pi is equivalent to or approximately equal to the sum of P2 and P3.

[0377] Figure 10N A number of cycles of a pressure profile 1045 are shown, where for each cycle, steam is delivered to a pressure Pi for a predetermined duration. Next, steam delivery is discontinued and the pressure is allowed to decrease to a pressure P3 below a baseline 1047 for another predetermined duration. Now, steam delivery is resumed and delivered to a pressure P2 for yet another predetermined duration. Next, steam delivery is discontinued and the pressure is allowed to decrease to a pressure P3 below the baseline 1047 for another predetermined duration. Thereafter, steam delivery is resumed and delivered to a pressure P2 for yet another predetermined duration. Finally, steam delivery is discontinued and the pressure is allowed to return to the baseline pressure 1047. In some embodiments, the pressure Pi is equivalent to or approximately equal to the sum of P2 and P3.

[0378] FIG. 10O A number of cycles of a pressure profile 1050 are shown, where for each cycle, steam is delivered to a pressure Pi for a predetermined duration. Next, steam delivery is discontinued and the pressure is allowed to decrease to a pressure P3 below a baseline 1052 for another predetermined duration. Now, steam delivery is resumed and delivered to a pressure P2 for yet another predetermined duration. Next, steam delivery is discontinued and the pressure is allowed to decrease to a pressure P3 below the baseline 1052 for another predetermined duration. Thereafter, steam delivery is resumed and delivered to a pressure Pi for yet another predetermined duration. Finally, steam delivery is discontinued and the pressure is allowed to return to the baseline pressure 1052. In some embodiments, the pressure Pi is equivalent to or approximately equal to the sum of P2 and P3.

[0379] FIG. 10P Multiple cycles of pressure curve 1055 are shown, wherein for each cycle, steam is delivered to pressure P1 for a predetermined duration. Next, steam delivery is stopped, and the pressure is allowed to drop to pressure P2, below baseline 1057, for another predetermined duration. Now, steam delivery resumes and is delivered to pressure P1 for another predetermined duration. Next, steam delivery is stopped, and the pressure is allowed to drop to pressure P2, below baseline 1057, for another predetermined duration. Thereafter, steam delivery resumes and is delivered to pressure P1 for another predetermined duration. Finally, steam delivery stops, allowing the pressure to return to the baseline pressure 1057. In some embodiments, pressure P1 is significantly greater than pressure P2.

[0380] FIG. 11A and 11B A single, coaxial dual-balloon catheter 1145a, 1145b according to an embodiment of this specification is shown. Catheters 1145a, 1145b include an elongated body 1146 having a proximal end 11511 and a distal end 1153, and a first lumen 1155, a second lumen 1156, and a third lumen 1157 located therein. In one embodiment, the elongated body 1146 is insulated. Catheters 1145a, 1145b include at least one positioning element 1148 near their distal end 1153. In various embodiments, the positioning element is an inflatable balloon. In some embodiments, the catheter includes more than one positioning element. FIG. 11B As shown, the coaxial conduit 1145b includes an outer conduit 1146b that accommodates the elongated body 1146.

[0381] exist FIG. 11A , 11B In the illustrated embodiment, catheters 1145a and 1145b include a distal second inflatable balloon 1148 and a proximal first inflatable balloon 1147 located near the distal end of the body 1146, with a plurality of infusion ports 1149 on the body 1146 between the two balloons 1147 and 1148. It should be understood that while balloons are preferred, other positioning elements as described above may also be used.

[0382] The body 1146 includes a first lumen 1155 (extending a portion of the entire length of the body 1146) in fluid communication with a first inlet port 1165 at a proximal end 11511 of the catheter body 1146 and with the proximal first balloon 1147 to inflate or deflate the proximal first balloon 1147 by supplying or aspirating air via the first lumen 1155. In one embodiment, using... FIG. 11A and 11BThe dual balloon catheter shown results in a treatment area that forms a seal and has a radius of 3 cm, a length of 9 cm, and a surface area of 169.56 cm 2 , a treatment volume of 254.34 cm 3 . The body 1146 includes a second lumen 1156 (extending the entire length of the body 1146) that is in fluid communication with a second input port 1166 at the proximal end 1152 of the catheter body 1146 and with the distal second balloon 1148 for inflating or deflating the distal second balloon 1148 by supplying or drawing air through the second lumen 1156. In another embodiment, the body includes only a first lumen for fluid communication with the proximal end of the catheter and first and second balloons for inflating and deflating the balloons. The body 1146 also includes an inline heating element 1150 disposed within a third lumen 1157 (extending the length of the body 1146) that is in fluid communication with a third input port 1167 at the proximal end 1152 of the catheter body 1146 and with the infusion port 1149. In one embodiment, the heating element 1150 is positioned within the third lumen 1157 proximate and just proximate the infusion port 1149. In one embodiment, the heating element 1150 includes a plurality of electrodes. In one embodiment, the electrodes of the heating element 1150 are folded back and forth to increase the surface contact area of the electrodes with a liquid supplied to the third lumen 1157. The third lumen 1157 is used to supply a liquid, such as water / saline, to the heating element 1150.

[0383] In various embodiments, the heating element 1150 is from 1 mm to 50 cm from the nearest port 1149, depending on the type of treatment procedure to be performed.

[0384] A fluid pump, an air pump, and an RF generator are connected to the proximal end of the body 1146. The air pump pushes air through the first and second lumens via the first and second inputs 1165, 1166 to inflate the balloons 1147, 1148 so that the catheters 1145a, 1145b remain in place for ablation treatment. The fluid pump pumps a liquid, such as water / saline, through the third lumen 1157 to the heating element 1150 through the third input 1167. The RF generator provides current to the electrodes of the heating element 1150, thereby causing the electrodes to heat and convert the liquid (flowing around the heating element 1150) to steam. The generated steam exits the port 1149 for ablation treatment of the target tissue. In some embodiments, the supply of liquid and current and the delivery of steam are controlled by a microprocessor.

[0385] FIG. 11Cis a flowchart of a number of steps performed in accordance with one embodiment of the present specification using catheters 1145a, 1145b to perform ablation in a body lumen, such as a patient's Barrett's esophagus. At step 1171, the catheters 1145a, 1145b are inserted into a body lumen. In one embodiment, the body lumen is a patient's esophagus. At step 1172, the balloons 1147, 1148 are inflated to demarcate a target ablation region, such as a Barrett's esophagus, and the catheters 1145a, 1145b are positioned so that the infusion port 1149 is positioned in the target ablation region, such as a portion of the Barrett's esophagus. At step 1173, liquid, such as water or saline, is provided to the proximal end of the catheters 1145a, 1145b. Finally, at step 1174, an electrical current is provided to the electrodes of the heating element 1150 to heat the electrodes and convert the liquid to vapor, where the generated vapor is delivered through the infusion port 1149 to ablate the target tissue, such as a patient's Barrett's esophagus. In various embodiments, steps 1173 and 1174 are performed simultaneously, or step 1174 is performed prior to step 1173.

[0386] FIG. 12A is an assembly diagram of a steam generation system 1200 in accordance with one embodiment of the present specification, which includes an induction heating unit 1205 connected or attached in fluid series (or in-line) with a catheter handle 1210 at the proximal end of the catheter handle 1210, while FIG. 12B and 12C is an exploded view of the components upstream and downstream of the induction heating unit 1205. Referring to FIG. 12A , 12B and 12C, the induction heating unit 1205 includes an induction coil 1212 surrounding a heating chamber 1215, which in turn houses a metallic or ferromagnetic core 1220. In some embodiments, the induction coil 1212 includes Litz electromagnetic wire wound in a tight spiral. A power cable 1207 extends from the induction coil 1212 to a power generator. The induction coil 1212 is located in a thermally insulated outer "soft skin" housing 1202. In some embodiments, the housing 1202 is a heat-stable overmolded component, including a low to medium durometer thermoplastic elastomer material, such as Santoprene®. Optionally, the induction heating unit 1205 also includes at least one thermocouple 1214 to measure the input and output temperatures of the heating chamber 1215.

[0387] In some embodiments, the heating chamber 1215 is made of a high temperature resistant material such as, but not limited to, PEEK (polyether ether ketone) or polysulfone. The core 1220 can be made of an electrically conductive metal or alloy such as, but not limited to, carbon steel, stainless steel or other ferromagnetic material such as Mu-metal (a soft magnetic alloy with high nickel / iron content used for high magnetic permeability and high efficient electromagnetic conductivity). An exemplary Mu-metal composition can contain approximately 77% nickel, 16% iron, 5% copper and 2% chromium or molybdenum.

[0388] The induction heating unit 1205 is reusable and is securely locked onto the heating chamber 1215. In some embodiments, the induction heating unit 1205 snap fits over the heating chamber 1215. In some embodiments, the heating chamber 1215 includes a male catch on its outer surface that locks onto a female catch on the inner surface of the housing 1202. In this way, the induction heating unit 1205 is positively locked onto the heating chamber 1215, isolating the operator from the heat affected zone during the ablation procedure. In accordance with aspects of the present description, once loaded onto the heating chamber 1215, the induction heating unit 1205 can be rotated about its longitudinal axis based on the operator’s preference to ensure that the working space around the catheter associated with the catheter handle 1210 is uncluttered.

[0389] Once current passes through the induction coil 1212, the core 1220 located inside the heating chamber 1215 acts as a heating element to convert saline / water received through the saline / water input line 1225 proximal end of the induction heating unit 1205 into steam. The saline / water input line 1225 originates from a disposable pump head and incorporates a first thumb latch 1237 operated by a first female connector housing 1236 at its distal end. The first female connector housing 1236 is configured to lock onto a first male connector end cap 1230 that extends from the proximal portion of the heating chamber 1215.

[0390] In some embodiments, the core 1220 is solid or tubular. Optionally, the core 1220 can have perforations or helical threads on its outer diameter to assist in the conversion of water into steam. The core 1220 is locked / retained within the heating chamber 1215 by the first male connector end cap 1230. The first male connector end cap 1230 connects the heating chamber 1215 to the first female connector housing 1236. Once the first male connector 1230 has been inserted into the first female connector housing 1236, a water tight seal is formed that prevents water / steam from leaking from the assembly. To disengage the first male connector portion and the first female connector portion, the first thumb latch 1237 is depressed and the portions are axially separated. The first male connector end cap 1230 contacts the water / steam and is made of a high temperature resistant material such as PEEK or polysulfone.

[0391] As FIG. 12A and 12CAs shown, a three-way flow control valve 1240 (e.g., a solenoid in one embodiment) is located downstream of the induction heating unit 1205 between the heating chamber 1215 and the second male connector 1245 (which connects the induction heating unit 1205 to the conduit handle 1210). FIG. 13A and 13B The diagrams show the de-energized and energized states of a three-way flow control solenoid valve 1340 (similar to valve 740). Valve 1340 is capable of the following types of flow operation: a) Normally closed flow operation—such as... FIG. 13A As shown, when valve 1340 is de-energized, pressure port 1305 is closed, and discharge port 1310 is connected to cylinder port 1315. When valve 1340 is energized, discharge port 1310 is closed, and pressure port 1305 is connected to cylinder port 1315; b) Normally open flow operation - as FIG. 13B As shown, when valve 1340 is de-energized, pressure port 1305 is connected to cylinder port 1315, and discharge port 1310 is closed. When valve 1340 is energized, pressure port 1305 is closed, and cylinder port 1315 is connected to discharge port 1310.

[0392] Return to reference FIG. 12A to 12C At the start of the ablation process, as the ablation system 1200 is set up and "ready," there will already be residual water stored in the system 1200. This water (or condensate) must be drained from the system 1200, and the amount of high-temperature steam injected into the target ablation site must be maximized. To prepare the system 1200, the generator is turned on and the duty cycle is activated. The condensate stream is diverted to the condensate drain line or pipe 1250 until only steam leaves the line. Once this occurs, the generator controller energizes the solenoid valve 1240 to the open position. FIG. 13B In this way, system 1200 is filled with steam and condensate is discharged, so that only steam is delivered from heating chamber 1215 to the conduit.

[0393] like FIG. 12C As shown, the second male connector 1245 connects the valve 1240 to the second female connector housing 1260, located near the end of the conduit handle 1210 and operated by the second thumb latch 1255. According to various aspects of this specification, the entire induction heating unit 1205 assembly is rotatable about the longitudinal axis of the conduit to ensure that the associated power cables and wiring can be positioned as needed by the operator.

[0394] FIG. 14A A dual-balloon, biaxial, multi-lumen catheter system 1400 according to an embodiment of this specification is shown, while FIG. 14B Two slender catheter shafts 1405 and 1407 for the catheter system 1400 are shown. See also... FIG. 14A and 14BThe catheter system 1400 includes distal and proximal inflatable anchor balloons 1410, 1412, which in one embodiment are connected to two different catheter shafts 1405, 1407, respectively. The catheter shafts 1405, 1407 are multi-lumen structures and are made of a polymer material capable of maintaining performance with continuous exposure to steam and temperature ranges of 110°C to 120°C, such as PEEK or polysulfone.

[0395] The outer shaft 1407 has a first lumen 1408 that houses the inner shaft 1405 and a second lumen 1409 that allows inflation fluid (e.g., air) to flow into the proximal balloon 1412 for inflation or to be suctioned for deflation. The inner shaft 1405 is axially telescoped within the first lumen 1408. The inner shaft 1405 has a first (steam) lumen 1415 to enable ablation fluid (e.g., steam) to flow through the catheter system 1400 and be released from a plurality of exit ports 1440 located between the distal balloon 1410 and the proximal balloon 1412, and a second lumen 1417 to allow inflation fluid (e.g., air) to flow into the distal balloon 1410 for inflation or to be suctioned for deflation. Thus, the two catheter shafts 1405, 1407 are capable of being moved axially independently of one another. In this way, the distance between the distal balloon 1410 and the proximal balloon 1412 can be adjusted prior to or during the ablation procedure, thereby adjusting the length of the coagulation / ablation zone 1420. In some embodiments, the length of the zone 1420 ranges from 4 cm to 6 cm. In some embodiments, the lumens 1409 and 1417 have a “smiley face” cross-section. However, in alternative embodiments, the cross-section can be other shapes, such as, but not limited to, circular, square, or rectangular.

[0396] Once positioned at the appropriate ablation treatment location, the distal and proximal balloons 1410, 1412 are inflated and anchored — e.g., against the esophageal wall — distally and proximally. This ensures that a defined, controlled coagulation zone 1420 is achieved prior to the generation and delivery of steam to the treatment site. In some embodiments, the diameters of both the proximal balloon 1410 and the distal balloon 1412 are inflatable to cover the range of desired esophageal diameters to be treated (ranging from 18 mm to 32 mm). Once the balloons are inflated in place, steam is generated at the proximal end of the catheter handle 1210 FIG. 12A ) outside the patient by an induction heating unit 1205 FIG. 12A ) and injected through the steam lumen 1415 of the inner shaft 1405.

[0397] A portion of the catheter shaft system 1400 between the balloons 1410, 1412 contains a plurality of eyelets configured axially around the shafts 1405, 1407. These eyelets serve as steam exit ports 1440. FIG. 14C and14D First and second eyelet patterns 1430, 1435 according to embodiments of the present specification are shown, respectively. The first eyelet pattern 1430 has a plurality of exit ports 1440 formed on both sides of the inner shaft 1405 and into the first (steam) lumen 1415, which are positioned about the circular axis at approximately 90 degrees on either side of the distal balloon inflation lumen 1417, while the second eyelet pattern 1435 has a plurality of exit ports 1440 on the side of the inner shaft 1405 opposite the distal balloon inflation lumen 1417 and into the first (steam) lumen 1415. Steam is delivered from these ports 1440, contacting and treating diseased tissue encapsulated in the coagulation / ablation zone 1420 bounded by the two balloons 1410, 1412.

[0398] FIG. 14E A cross-sectional view of a multi-lumen shaft 1450e of the catheter system 1400 according to embodiments of the present specification is shown. FIG. 14A The shaft 1450e includes a first innermost lumen 1452e that allows water / saline to flow therein and also houses a heating element, such as a flexible heating chamber (including a plurality of electrodes) or an inductive heating chamber (including an inductive coil), a second lumen 1454e that provides a path for distal balloon 1410 inflation or control of distal positioning element, a third lumen 1456e configured as an inner sheath, and a fourth lumen 1458e that provides a path for proximal balloon 1412 inflation or control of proximal positioning. In some embodiments, the heating element is positioned substantially proximate to the plurality of steam exit ports 1440. In various embodiments, the heating element is positioned no more than 6 inches distally behind the proximal balloon 1412.

[0399] FIG. 15A and 15B A telescoping catheter handle 1500 for use with the dual balloon, dual shaft, multi-lumen catheter system 1400 according to embodiments of the present specification is shown. FIG. 14A FIG. 14A , 14B ​According to embodiments of this specification, 15A and 15B, the handle 1500 includes a first handle member 1505 in a first position relative to a second handle member 1510. In one embodiment, the first handle member 1505 has an elongated body having a proximal and a distal end, and includes a female connector 1502 operated by a thumb latch 1503 at the proximal end. In one embodiment, the second handle member 1510 has an elongated body having a proximal and a distal end. The second handle member 1510 extends and retracts into and out of the distal end of the first handle member 1505 to adjust the distance between the distal balloon 1410 and the proximal balloon 1412. A connector 1515 is included at the distal end of the second handle member 1510 and includes a Luer member 1517 (at the distal end of the connector 1515) for attaching the catheter handle 1500 to the working channel port of the endoscope handle. The axis of the dual-balloon multi-lumen catheter system 1400 extends beyond the distal end of the second handle member 1510.

[0400] A first inlet port 1525 is located at a first handle assembly 1505 and attached to an inner shaft 1405 to allow inflation / deflation of the distal balloon 1410. A second inlet port 1530 is located at a second handle assembly 1510 and connected to an outer shaft 1407 to allow inflation / deflation of the proximal balloon 1412. The first handle assembly 1505 includes a first finger-threaded member 1532 to extend the catheter system 1400 beyond the endoscope, and the second handle assembly 1510 includes a second finger-threaded member 1535 to adjust the length of the coagulation / ablation zone 1420.

[0401] exist FIG. 15A In the first position shown, the first handle component 1505 is located closest to the proximal end relative to the second handle component 1510. (See reference...) FIG. 15B The second handle component 1510 includes a plurality of markings 1533 along its body. In one embodiment, the markings 1533 are numbers. The first handle component 1505 includes a window 1540 near its distal end, which aligns with one of the markings as the first handle component 1505 moves longitudinally relative to the second handle component 1510. The markings 1533 in the window 1540 indicate the length by which the catheter system 1400 extends beyond the distal end of the endoscope's working channel and into the patient's body cavity. FIG. 15B The catheter handle 1500 is shown, with the first handle part 1505 in a second position relative to the second handle part 1510. Marking 1533 in window 1540 indicates to the operator that the first handle part 1505 is in its most distal position relative to the second handle part 1510, and that the catheter system 900 is fully extended within the patient's body cavity.

[0402] Now refer to FIG. 15C as well as FIG. 12A ,12B In various embodiments, catheter handle 1500 is connected at its distal end to the working channel port of endoscope 1545 by a luer fitting 1517 or a latching type locking mechanism. At its proximal end, catheter handle 1500 is connected to induction heating unit 1205 by female connector 1502 operated by thumb latch 1503. FIG. 15C An exploded view of induction heating unit 1205 is shown, showing the assembly comprising heating chamber 1215 and core 1220, with housing 1202 comprising induction coil 1212 slidably attached on core 1220. Power cable 1207 extends from induction coil 1212 to the generator. Three-way flow control valve 1240 is also shown located between catheter handle 1500 and induction heating unit 1205. Female connector 1502 operated by thumb latch 1503 provides the operator with a mechanism to connect / detach valve 1240 as well as the assembly comprising heating chamber 1215 and core 1220 from catheter handle 1500.

[0403] FIG. 15D is an exploded view of second handle component 1510, FIG. 15E is a perspective view of second handle component 1510 detached from first handle component 1505, and FIG. 15F is a cross-sectional view of second handle component 1510. Referring now to FIG. 15D , 15E , 15F, and FIG. 14A and 14B , second handle component 1510 houses a tube 1550 that is connected at its proximal end to second access port 1530. As shown in FIG. 15E , 15F , catheter system 1400 passes along second handle component 1510. Second access port 1530 is in fluid communication with second lumen 1409 of outer shaft 1407 through slit 1419 to enable inflation / deflation of proximal balloon 1412.

[0404] FIG. 15G is a cross-sectional view of first handle component 1505, and FIG. 15H is a cross-sectional view of first handle component 1505. Referring now to FIG. 15G , 15H , and FIG. 14A , 14B , first access port 1525 is attached (in one embodiment, threaded) to manifold 1555 and is in fluid connection with second lumen 1417 of inner shaft 1405 to enable inflation / deflation of distal balloon 1410. The housing 1560 of female connector 1502 is attached to female luer 1559 of manifold 1555.

[0405] FIG. 16A shows a catheter system 1400 for use in accordance with an embodiment of the present specification,FIG. 14A The dual-balloon multi-lumen catheter system 1400 and the single multi-lumen axis 1600. Now, also refer to... FIG. 16A and 14A The distal and proximal balloons 1410 and 1412 are connected to a single multi-lumen shaft 1600. As a result, the distance between the balloons 1410 and 1412 is fixed, and therefore the length of the condensation / ablation zone 1420 is also fixed. The distal portion of the shaft 1600 between the balloons 1410 and 1412 includes multiple orifices serving as vapor exit ports 1440.

[0406] According to one embodiment, shaft 1600 includes five cavities and is made of a polymeric material, such as PEEK or polysulfone, capable of maintaining performance under continuous exposure to vapor / steam and temperatures ranging from 110°C to 120°C. A first cavity 1605 allows ablative fluid (e.g., vapor) to flow through and exit from a vapor exit port 1440. A second cavity 1610 is in fluid communication with the distal balloon 1410 to allow inflation fluid (e.g., air) to flow through or be aspirated therethrough for inflation / deflation of balloon 1410. A third cavity 1615 is in fluid communication with the proximal balloon 1412 to allow inflation fluid (e.g., air) to flow through or be aspirated therethrough for inflation / deflation of balloon 1412. Fourth and fifth cavities 1620, 1625 serve as auxiliary cavities to the first (vapor) cavity 1605. The fourth and fifth cavities 1620, 1625 are in fluid communication with the first inner cavity 1605 at the distal portion of the shaft 1600, so as to allow steam to flow from the first inner cavity 1605 through the fourth and fifth cavities 1620, 1625 and out of the exit port 1440, thereby ablating the target tissue.

[0407] FIG. 16B The illustration shows the configuration of a steam exit port 1440 at the distal portion of shaft 1600 according to an embodiment of this specification. As shown, the steam exit port 1440 is arranged along the longitudinal axis of shaft 1600 on a first side 1630 and a second side 1635, such that the two sides 1630 and 1635 are 180° apart. FIG. 16C , 16D As shown, the steam or steam cavity 1605 is located at the center of the shaft 1600. In order to inject steam from the central steam cavity 1605, the port 1440 is drilled / laser-cut through the outer wall 1640 of the shaft 1600, through the auxiliary cavities 1620, 1625 and through the inner wall 1645 of the steam cavity 1605.

[0408] FIG. 16E and 16F Perspective and exploded views of a non-telescopic catheter handle 1650 used with a single multi-lumen shaft 1600 according to embodiments of this specification are shown. (Refer to...) FIG. 16E and 16F as well asFIG. 14A The catheter handle 1650 has an elongated body 1652 that includes a first access port 1655 attached to a first manifold 1656 that keeps the port 1655 in fluid communication with the second lumen 1610 to enable inflation / deflation of the distal balloon 1410, and a second access port 1660 attached to a second manifold 1662 that keeps the port 1660 in fluid communication with the third lumen 1615 to enable inflation / deflation of the proximal balloon 1412. In some embodiments, the first and second manifolds 1656, 1662 are configured to be coupled to the shaft 1600 and are made of PEEK / Polysulfone. First and second lines (not shown) are connected to the first and second ports 1655, 1660, respectively. The proximal ends of the two lines are connected to two independent inflation pumps that are mounted in a generator. Inflation and deflation (if needed) of the two balloons 1410, 1412 are controlled by the two lines. In some embodiments, both lines are flexible polymer extrusions and are disposable.

[0409] A connector 1666 is located at the distal end of the body 1652 and a luer fitting is connected at the distal end of the connector 1666 to enable the handle 1650 to be attached to the working channel port of an endoscope. The catheter shaft 1600 extends beyond the distal end of the connector.

[0410] A thumb screw 1665 is positioned near the distal end of the handle 1650 to enable adjustment of the shaft 1600 out of the endoscope when the handle 1600 is attached to the working channel of the endoscope. A female connector 1675 operated by a thumb latch 1670 is located at the proximal end of the handle 1650 to enable an inductive heating unit (e.g., unit 1205) to be attached to the handle 1650 in series or in-line (similar to that shown in FIG. 15C The second manifold 1662 is fluidically connected to the housing of the female connector 1675.

[0411] According to aspects of the present description, it is preferred that the thumb screw 1665 and the thumb latch 1670 face in the same direction so that they are facing the operator when the handle 1650 is locked on the endoscope. It is also preferred that the two ports 1655, 1660 are positioned or oriented at approximately 90 degrees from the thumb latch 1670 so that they provide a good ergonomic effect for the operator and do not interfere with the operation of the handle 1650 during the ablation procedure.

[0412] According to one aspect of the present description, FIG. 17C An inductive heating unit is shown detachably mounted on an endoscope, while FIG. 17A and 17B A perspective view of a clamp according to embodiments of the present description is shown. Referring now to FIG. 17A ,17B and 17C and FIG. 12A The induction heating unit 1205, which includes a heating chamber 1215 (with a core 1220) and an assembly of induction coils 1212, is mounted on the body of the endoscope 1705 below the bifurcation 1707 of the biopsy port on the endoscope 1705. Mounting the induction heating unit 1205 to this location reduces the lever arm and weight on the catheter handle 1710 and moves multiple components away from the direct handle workspace around the thumb screws 1715, 1720 and the distal and proximal balloon inflation ports 1725, 1730 for inflation / deflation of the distal and proximal balloons of a dual balloon multi-lumen catheter (e.g., catheter system 1400 of FIG. 14A In some embodiments, the catheter handle 1710 is a telescoping handle (e.g., handle 1500 of FIG. 15A ), while in other embodiments, the catheter handle 1710 is a non-telescoping handle (e.g., handle 1650 of FIG. 16E ).

[0413] The induction heating unit 1205 is removably attached to the shaft of the endoscope 1705 using a soft clamp 1735. In one embodiment, the clamp 1735 includes a soft, deformable rubber grip 1740 attached to a rigid polymer frame 1745 that incorporates a bracket 1750 to mount the induction heating unit 1205. In one embodiment, the bracket 1750 is configured as a C-shaped clamp. As shown in FIG. 17D According to one embodiment, the heating chamber 1215, the core 1220, and the two male coupler end caps 1230 are pre-assembled as a module 1770. Next, the module 1770 is slidably inserted into the housing 1202, which includes the induction coils 1212, thereby forming the induction heating unit 1205. Subsequently, the induction heating unit 1205 is slid into the approximately C-shaped space 1775 of the bracket 1750.

[0414] Referring again to FIG. 17A , 17B and 17C, once the induction heating unit 1205 is slidably mounted into the C-shaped clamp, the assembly is loaded onto the shaft of the endoscope 1705 below the biopsy port. The deformable nature of the rubber grip 1740 provides a secure connection to the endoscope 1705. This orientation of the clamp 1735 can be easily adjusted to accommodate the preferred orientation of the induction heating unit 1205 during an ablation procedure. The clamp 1735 can be removed by simply pulling the bracket assembly outward.

[0415] The disposable water / saline line 1755 connects at the proximal end of the induction heating unit 1205 to a female coupling 1756 operated by a thumb latch, while the disposable steam delivery line 1760 connects to the unit 1205 through a female coupling 1757 operated by a thumb latch at the distal end of the unit 1205 and to the handle 1710 through another female coupling 1762 operated by a thumb latch at the proximal end of the handle 1710. In various embodiments, the steam delivery line 1760 is made of PEEK, polysulfone, high temperature nylon, polycarbonate, or polyimide material. In some embodiments, the line can also be braided for added strength to make the line more kink resistant during surgery. It will be appreciated that although not shown in FIG. 18, a three-way flow control valve, such as valve 1240, is located between the unit 1205 and the handle 1710. FIG. 17C

[0416] FIG. 18 FIG. 19 is a schematic diagram of an embodiment of a disposable tubing set 1800 for use with the ablation system of the present specification. In one embodiment, the tubing set 1800 includes a rigid plastic spike 1801 for piercing a saline bag or reservoir 1802, a flexible polymeric tube 1803, a pressure sensor 1804, and a coupling with a thumb latch 1805. The pressure sensor 1804 is connected to a microcontroller on the steam generator and is used to monitor and control pressure in the system after steam generation and delivery has begun. The coupling with the thumb latch 1805 is configured to securely lock the tube 1803 to the proximal end of the induction heating unit. Optionally, in one embodiment, the coupling with the thumb latch 1805 is replaced with a male coupling to allow for the use of a reusable tube. FIG. 17C The proximal end of the induction heating unit 1205 is shown connected to the female coupling 1756. In one embodiment, the tubing set 1800 also includes a flow control component with a thumb dial 1806 for controlling the flow from the saline bag or reservoir 1802.

[0417] The tubing set 1800 also includes first and second disposable inflation line tubes, which are flexible polymeric extrusions. The distal ends of the first and second inflation line tubes are connected to the distal and proximal balloon inflation ports of the catheter handle, respectively. The proximal ends of the first and second inflation line tubes are connected to two independent inflation pumps. Inflation and deflation (if needed) of the distal and proximal balloons is controlled through the first and second inflation line tubes.

[0418] FIG. 19 ​is an illustration of a telescoping catheter handle 1910 attached to an endoscope 1950 according to an embodiment of the present specification. A proximal balloon inflation line 1905 is attached to a proximal balloon inflation port 1906 for inflation of the proximal balloon, and a distal balloon inflation line 1908 is attached to a distal balloon inflation port 1909 for inflation of the distal balloon. An induction heating unit 1915 is attached to the proximal end of the catheter handle 1910 and includes a power cord 1917 for providing current to the conductive wire of the induction coil. A saline delivery line 1920 is connected to the proximal end of the induction heating unit 1915. A three-way valve 1912 is included between the catheter 1910 and the induction heating unit 1915 for readying the system to remove residual water before steam is generated.

[0419] FIG. 20A is an assembled view of a steam generator 2050, FIG. 20B is a partially exploded view of a steam generator 2050, FIG. 20C is an exploded view of a disposable pump of a steam generator 2050, FIG. 20D is an assembled view of a disposable pump, FIG. 20E shows a disposable pump in fluid connection with other components of a steam generator 2050 according to an embodiment of the present specification. Referring to FIG. 20A to 20E In the meantime, the steam generator 2050 includes a water / salt bag or reservoir 2055 fluidically attached with a first tube 2060. At one end, the first tube 2060 has a rigid plastic spike 2056 to pierce the container 2055, while at the other end, the first tube 2050 has a female connector 2058 operated by a first latch for quick connection to a male connector end cap 2065 of an input tube portion 2070 of a disposable pump 2075.

[0420] The disposable pump 2025 includes a pump head 2072 attached to a pump motor housing 2074. The first tube 2060 feeds water / saline from the reservoir 2055 to the pump 2075. Pressurized water / saline output by the pump 2075 is forwarded by a second tube 2080, which is attached to a second male joint end cap 2085 of a tube portion 2090 of the pump 2075 by a second female coupler 2095. The second tube 2080 supplies pressurized water / saline to the heating chamber of the induction heating unit.

[0421] Gastrointestinal ablation

[0422] FIG. 21 shows an ablation catheter placed in the upper gastrointestinal tract with a Barrett's esophagus for selective ablation of Barrett's tissue according to an embodiment of the present specification. Referring to FIG. 21The upper gastrointestinal tract includes a Barrett's esophagus 2141, a cardia 2142, a gastroesophageal junction 2143, and a displaced squamocolumnar junction 2144. The region between the gastroesophageal junction 2143 and the displaced squamocolumnar junction 2144 is the Barrett's esophagus 2141, which is the target for ablation. The distal end of the cardia 2142 is the stomach 2145, and the proximal end of the cardia 2142 is the esophagus 2146. The ablation device enters the esophagus 2146, and the balloons 2110, 2112 are positioned such that the balloon 2112 is placed in the cardia 2142 abutting the gastroesophageal junction 2143. This fixes the ablation catheter and its infusion port (as shown in FIG. 4A

[0423] FIG. 22 is a flowchart showing a method for Barrett's esophagus ablation according to one embodiment of the present specification. Referring to FIG. 22 In a first step 2201, the patient is endoscoped to measure the length of the patient's Barrett's esophagus. Thereafter, in step 2202, the measured length is input into the processor of the ablation system for calculating the amount of ablation energy required to ablate the Barrett's esophagus. In another embodiment, the measured length is used as a reference to select a catheter with an appropriate ablation segment length to approximate the length of the Barrett's esophagus. Next, in step 2203, a catheter having a first positioning balloon at its distal end and a second positioning balloon at its proximal end is passed through or along the endoscope channel such that the distal balloon is positioned near the patient's cardia tissue and the proximal balloon is positioned near the top of the Barrett's esophagus.

[0424] In the next step 2204, both balloons are inflated to a set pressure (PI), and the diameter of the Barrett's esophagus is measured using the proximal balloon. As shown in step 2205, this diameter is input into the processor, either manually or automatically, and the surface area of the Barrett's segment to be ablated is calculated.

[0425] Next, in step 2206, one or more vapors are circulated through one or more vapor delivery ports on the catheter to the esophageal mucosa at a temperature range of 90 to 100 °C to ablate the Barrett's esophagus. In step 2207, the balloon pressure is maintained at a pressure P2 greater than or equal to pressure PI during delivery of the ablation agent. Optionally, in step 2208, the balloon is deflated to a pressure P3 less than or equal to pressure PI between ablation cycles. Finally, after the ablation is completed in step 2209, the endoscope and catheter are removed.

[0426] ​It should be appreciated that any ablation catheter or system of the present description for ablating tissue in an organ can be used with a controller configured to limit the pressure within the organ generated by the ablation fluid (e.g., vapor) to less than 5 atmospheres or 100 psi.

[0427] FIG. 23A A deflated view 2340d, a lateral inflated view 2340l, and an anterior inflated view 2340f of an ablation catheter 2340 according to one embodiment of the present description is shown having an exclusion membrane 2349 for duodenal ablation. In some embodiments, the catheter 2340 includes a water-cooled catheter having a proximal inflatable balloon 2342 and a distal inflatable balloon 2344 with an exclusion membrane 2349 extending from a proximal end of the proximal balloon 2342 to a distal end of the distal balloon 2344. A plurality of vapor delivery ports 2343 are located on the catheter 2340 between the proximal balloon 2342 and the distal balloon 2344. Once the balloons 2342, 2344 are inflated, as shown in the lateral view 2340, the stretching of the exclusion membrane 2349 between the balloons 2342, 2344 causes the catheter 2340 to bend, helping to position the exclusion membrane over the ampulla of Vater, providing a protective shield over the ampulla during vapor ablation therapy.

[0428] FIG. 23B An ablation catheter 2340 according to one embodiment of the present description is shown deployed in a patient's duodenum 2350. The catheter 2340 has been deployed through a working channel of an endoscope 2341 such that the distal inflatable balloon 2344 is positioned in the distal duodenum 2350d, proximate the jejunum 2352, and the proximal inflatable balloon 2342 is positioned in the proximal duodenum 2350p. The exclusion membrane 2349 is positioned over the ampulla at the VATER 2351 to prevent damage to the ampulla 2351 by ablation agent 2345 delivered to the duodenum 2350. The proximal portion 2349p and the distal portion 2349d of the exclusion membrane 2349 are attached to the proximal inflatable balloon 2342 and the distal inflatable balloon 2344, respectively, such that once the catheter 2340 is deployed, the exclusion membrane 2349 is stretched to conform to the shape of the duodenum 2350. FIG. 23A

[0429] In various embodiments, the ablation therapy provided by the vapor ablation systems of the present description is delivered to treat various conditions, and the efficacy of the treatment is determined by measuring certain physiological parameters over a time range of at least six weeks to two years after the treatment, as further described below. If the treatment endpoints have not been reached after at least six weeks, the ablation therapy is repeated. The physiological parameters are then measured after at least another six weeks, and the ablation therapy can be repeated and evaluated in similar six-week cycles until the desired treatment endpoints are reached.

[0430] ​In various embodiments, the ablation therapy provided by the steam ablation system of the present specification, particularly duodenal ablation, is used to treat at least one of: fatty liver, non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis, type 2 diabetes, metabolic syndrome, overweight patients, and obesity. In various embodiments, the ablation therapy provided by the steam ablation system of the present specification, particularly duodenal ablation, is delivered to achieve the following therapeutic endpoints: treatment of type 2 diabetes by achieving a reduction in HbAlc or fasting glucose levels of at least 10% as measured at least 6 weeks after treatment; treatment of metabolic syndrome; or treatment of hyperlipidemia by achieving a reduction in total cholesterol or LDL or triglycerides of at least 5% or an improvement in HDK cholesterol of at least 5% as measured at least 6 weeks after treatment.

[0431] In the context of treating fatty liver or nonalcoholic fatty liver disease (NAFLD) / nonalcoholic steatohepatitis, the ablation therapy provided by embodiments of the steam ablation system of the present specification, particularly duodenal ablation, is delivered to achieve the following treatment endpoints when measured at least 6 weeks post-treatment: at least a 10% reduction in ALT or AST levels; a 10% relative improvement in serum ferritin levels or an absolute level no more than 1.5 ULN (upper limit of normal); at least a 5% relative improvement in hepatic steatosis (HS), or a HS of no more than 5% as measured by liver biopsy; at least a 5% relative improvement in HS as measured by magnetic resonance (MR) imaging, or by spectroscopy or proton density fat fraction; at least a 5% relative improvement in nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS); at least a 5% relative improvement in the NAFLD Activity Score; at least a 5% relative improvement in the Steatosis Activity Fibrosis (SAF) score; at least 10% of patients show a decrease in the mean annual rate of fibrosis progression as measured by histology, Fibrosis-4 (FIB-4) index, aspartate aminotransferase (AST) to platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) Panel, FibroTest, and Hepascore), or imaging (transient elastography (TE), MR elastography (MRE), acoustic radiation force impulse imaging, and ultrasound shear wave elastography); at least a 5% relative improvement in circulating levels of cytokeratin-18 fragment; at least a 5% relative improvement in FIB-4 index, aspartate aminotransferase (AST) to platelet ratio index (APRI), serum biomarkers (Enhanced Liver Fibrosis (ELF) Panel, FibroTest, and Hepascore), or imaging (TE, MRE, acoustic radiation force impulse imaging, and ultrasound shear wave elastography); at least a 5% relative improvement in liver stiffness as measured by vibration-controlled transient elastography (VCTE (FibroScan)); at least 10% of patients show an improvement in NAS by 2 points, at least an improvement in hepatocellular ballooning by 1 point, and an improvement in lobular inflammation or steatosis score by 1 point with no increase in fibrosis score; at least 10% of patients show an improvement in NFS score; at least 5% of patients show an improvement in the above-mentioned NAFLD parameters compared to sham intervention or placebo. In various embodiments, the relative treatment goals and endpoints are an improvement relative to one or more pre-treatment levels of the respective stated physiological indicators.

[0432] In various embodiments, the ablation treatment provided by the steam ablation system of the present specification, particularly duodenal ablation, treats human obesity by achieving one of the following treatment endpoints when measured at least six weeks after treatment: a reduction in the human’s total body weight of at least 1% relative to the human’s total body weight prior to ablation; a reduction in the human’s overweight body weight of at least 1% relative to the human’s overweight body weight prior to ablation; a reduction in the human’s total body weight of at least 1% relative to the human’s total body weight prior to ablation and a reduction in the human’s health level of no more than 5% relative to the human’s health level prior to ablation; a reduction in the human’s overweight body weight of at least 1% relative to the human’s overweight body weight prior to ablation and a reduction in the human’s health level of no more than 5% relative to the human’s health level prior to ablation; a reduction in the human’s preprandial ghrelin level of at least 1% relative to the human’s preprandial ghrelin level prior to ablation following at least one ablation; a reduction in the human’s postprandial ghrelin level of at least 1% relative to the human’s postprandial ghrelin level prior to ablation following at least one ablation; an increase in the patient’s exercise output of at least 1% relative to the patient’s exercise output prior to ablation following at least one ablation session; an increase in the human’s glucagon-like peptide-1 level of at least 1% relative to the human’s glucagon-like peptide-1 level prior to ablation following at least one ablation; an increase in the human’s leptin level of at least 1% relative to the human’s leptin level prior to ablation following at least one ablation; a reduction in the patient’s appetite over a predetermined period of time relative to the patient’s appetite prior to ablation following at least one ablation; an increase in the human’s peptide YY level of at least 1% relative to the human’s peptide YY level prior to ablation following at least one ablation; a reduction in the human’s lipopolysaccharide level of at least 1% relative to the human’s lipopolysaccharide level prior to ablation following at least one ablation; a reduction in the human’s motilin-related peptide level of at least 1% relative to the human’s motilin-related peptide level prior to ablation following at least one ablation; an increase in the human’s cholecystokinin level of at least 1% relative to the human’s cholecystokinin level prior to ablation following at least one ablation; an increase in the human’s resting metabolic rate of at least 1% relative to the human’s resting metabolic rate prior to ablation following at least one ablation; an increase in the human’s plasma beta-endorphin level of at least 1% relative to the human’s plasma beta-endorphin level prior to ablation following at least one ablation; a decrease in the patient’s hemoglobin Alc level equal to at least 0.3%; a human triglyceride level is reduced by at least 1% relative to the human triglyceride level prior to the at least one ablation; a human total blood cholesterol level is reduced by at least 1% relative to the human total blood cholesterol level prior to the at least one ablation; a human blood glucose level is reduced by at least 1% relative to the human blood glucose level prior to the at least one ablation; a human gut microbiota composition is modulated from a first state to a second state after the at least one ablation, wherein the first state has a first level of Bacteroides and a first level of Firmicutes, wherein the second state has a second level of Bacteroides and a second level of Firmicutes, wherein the second level of Bacteroides is at least 3% greater than the first level of Bacteroides, and wherein the second level of Firmicutes is at least 3% less than the first level of Firmicutes; a cumulative daily dose of a patient’s anti-diabetic medication is reduced by at least 10% after the at least one ablation; a patient’s blood lipid level is improved by at least 10% after the at least one ablation; a patient’s LDL cholesterol is reduced by at least 10% after the at least one ablation; and, a patient’s VLDL cholesterol is reduced by at least 10% after the at least one ablation. In various embodiments, the relative treatment targets and endpoints are provided relative to one or more pre-treatment levels of the respective stated physiological indicators.

[0433] The ablation systems and methods of the present description, and particularly duodenal ablation, can be used to treat a disease including any one of obesity, overweight, eating disorders, metabolic syndrome and diabetes, NASH / NAFLD, or polycystic ovary disease. According to various aspects of the present description, the ablation systems and methods, and particularly duodenal ablation, are capable of treating people with a BMI (Body Mass Index) of 25 or higher (overweight 25-30, obese 30 or higher, morbidly obese above 35). According to various aspects of the present description, the ablation systems and methods, and particularly duodenal ablation, are also capable of treating people with an HbAlc level of at least 6.5 gm%, a fasting blood glucose level of at least 126 mg / dL, or a random plasma glucose level of at least 200 mg / dL, a 2-hour plasma glucose level of at least 200 mg / dL (11.1 mmol / L) during an oral glucose tolerance test (OGTT). The ablation systems and methods, and particularly duodenal ablation, can also be used to treat people with non-diabetic, normotensive, overweight individuals with a serum triglyceride concentration of at least 130 mg / dL (1.47 mmol / L), a ratio of triglyceride to high-density lipoprotein (HDL) cholesterol concentration of at least 3.0 (1.8 SI units), and a fasting insulin concentration of at least 5.7 μU / mL (109 pmol / L). The ablation systems and methods, and particularly duodenal ablation, can also be used to treat patients with insulin resistance (defined as a homeostatic model assessment for insulin resistance (HOMA-IR) of at least 1.6) or related diseases. The ablation systems and methods, and particularly duodenal ablation, can also be used to treat patients with dyslipidemia.

[0434] FIG. 24 is a flowchart illustrating a colon ablation method according to one embodiment of the present description. Referring to FIG. 24 , a first step 2401 includes inserting an endoscope into a lower gastrointestinal tract of a patient. Next, in step 2402, a catheter of an ablation device is passed through the endoscope, where the catheter includes a hollow shaft through which an ablation agent can pass, at least one positioning element, at least one input port for receiving the ablation agent, and at least one infusion port for delivering the ablation agent. The catheter is passed through the endoscope such that the positioning element is positioned in proximity to a colon tissue to be ablated. In one embodiment, the ablation device includes a controller including a microprocessor for controlling delivery of the ablation agent. In step 2403, the positioning element is deployed in a colon lumen of the patient such that the positioning element contacts a portion of the patient’s colon, and the catheter and infusion port are positioned within the colon lumen. In one embodiment, the positioning element is positioned on and encloses the colon tissue. Finally, in step 2406, the ablation agent is delivered through the infusion port to ablate the colon tissue.

[0435] Optionally, in step 2404, at least one dimension of the colon is measured using a sensor, and in step 2405, the measurement is used to determine the amount of ablation agent to be delivered.

[0436] In various embodiments, the ablation therapy provided by the steam ablation system of the present specification is delivered to achieve the following treatment endpoints for duodenal ablation: maintaining tissue temperature at 100°C or less; ablating at least 50% of the surface area of the duodenal mucosa; ablating the duodenal mucosa without significantly ablating the ampullar mucosa; reducing fasting blood glucose by at least 5% relative to pre-treatment fasting blood glucose; reducing HbAlc by at least 5% relative to pre-treatment HbAlc; reducing total body weight by at least 1% relative to pre-treatment body weight; reducing overweight body weight by at least 3% relative to pre-treatment overweight body weight; reducing mean blood pressure by at least 3% relative to pre-treatment mean blood pressure; and reducing total cholesterol by at least 3% relative to pre-treatment total cholesterol.

[0437] FIG. 25 An upper gastrointestinal tract with a bleeding vascular lesion treated by an ablation device according to one embodiment of the present specification is shown. The vascular lesion is a visible vessel 2561 at the base of an ulcer 2562. An ablation catheter 2563 passes through the channel of an endoscope 2564. A conical positioning element 2565 is placed over the visible vessel 2561. The conical positioning element 2565 has a known length ‘l’ and diameter ‘d’ which are used to calculate the amount of thermal energy required to coagulate the visible vessel to achieve hemostasis. The conical positioning element has an optional insulating membrane which prevents the escape of thermal energy or steam from the site of disease.

[0438] In one embodiment, the positioning accessory must be separated from the ablation region by a distance greater than 0.1 mm, preferably 1 mm, more preferably 1 cm. In one embodiment, the length ‘l’ is greater than 0.1 mm, preferably 5 mm to 10 mm. In one embodiment, the diameter “d” depends on the size of the lesion and can be between 1 mm to 10 cm, preferably 1 to 5 cm.

[0439] FIG. 26 is a flowchart showing an upper gastrointestinal ablation method according to one embodiment of the present specification. Reference is made to FIG. 26The first step 2601 includes inserting an endoscope into the upper gastrointestinal tract of a patient. Next, in step 2602, a catheter of an ablation device is passed through the endoscope, where the catheter includes a hollow shaft through which an ablative agent can pass, at least one positioning element, at least one input port for receiving the ablative agent, and at least one infusion port for delivering the ablative agent. The catheter is passed through the endoscope such that the positioning element is positioned near the upper gastrointestinal tract tissue to be ablated. In one embodiment, the ablation device includes a controller that includes a microprocessor for controlling delivery of the ablative agent. In step 2603, the positioning element is deployed in the lumen of the upper gastrointestinal tract of the patient such that the positioning element contacts a portion of the upper gastrointestinal tract of the patient and the catheter and infusion port are positioned in the lumen of the upper gastrointestinal tract. In one embodiment, the positioning element is positioned over and around the upper gastrointestinal tract tissue. Finally, in step 2606, the ablative agent is delivered through the infusion port to ablate the upper gastrointestinal tract tissue.

[0440] Optionally, in step 2604, a sensor is used to measure at least one dimension of the upper gastrointestinal tract, and in step 2605, the measurement is used to determine the amount of ablative agent to be delivered.

[0441] FIG. 27A is an illustration of a pancreatic ablation of a pancreatic tumor 2765 according to one embodiment of the present specification. An ablation device 2760 includes a needle 2761 configured to be inserted into a lesion to deliver a vapor for ablation. The ablation device 2760 is passed through a channel of an echo endoscope 2763 that has been inserted into the gastrointestinal tract 2764 of a patient to view the pancreas 2766 of the patient. Vapor is delivered through the needle 2761 of the ablation device 2760 to ablate the pancreatic tumor 2765.

[0442] FIG. 27B is a flowchart listing the steps involved in one embodiment of a pancreatic ablation method. In step 2770, an echo endoscope is advanced near pancreatic tissue. In step 2771, the echo endoscope is used to locate a pancreatic lesion to be ablated. In step 2772, the echo endoscope is used to measure the dimensions of the lesion. In step 2773, one of the measured dimensions is used to calculate the amount of vapor to be delivered. In step 2774, an ablation needle is passed through a channel in the echo endoscope and through a puncture in the gastrointestinal wall into the pancreatic lesion. In step 2775, suction is optionally applied on the needle to aspirate fluid / cells from the lesion. In step 2776, vapor is passed through the needle into the pancreatic lesion to heat the lesion while water is circulated through an outer sheath of the needle to cool the puncture site. In step 2777, the ablation area is observed with the echo endoscope. Once sufficient ablation is achieved in step 2778, delivery of the vapor is stopped. In step 2779, the ablation needle is removed from the echo endoscope and the echo endoscope is removed from the patient.

[0443] FIG. 27C is a flowchart listing steps involved in one embodiment of a method of pancreatic cyst ablation. In step 2780, endoscopic ultrasound (EUS) is performed to determine the size of the cyst. In step 2781, the size of the cyst is input into a microprocessor of a controller of the ablation system to calculate the amount of ablation therapy to be delivered. In step 2782, an echogenic tip steam delivery needle is placed into the cyst under EUS guidance. In step 2783, some fluid is aspirated from the cyst to reduce the fluid volume of the cyst. In step 2784, one or more steam delivery cycles are delivered to the cyst to heat the fluid in the cyst to a temperature range of 45 to 100 °C, ablating the inner layer of the cyst wall without significantly damaging surrounding pancreatic tissue. Optionally, in step 2785, post-ablation fluid is aspirated from the cyst. In step 2786, the needle is removed from the cyst.

[0444] In various embodiments, the ablation therapy delivered by the steam ablation system of the present specification is delivered to achieve the following treatment endpoints for a tumor in or near a bile duct: maintaining a tissue temperature of 100 °C or less; ablating at least 50% of the surface area of the target cancerous mucosa to a sufficient depth such that the cross-sectional area after ablation is improved by at least 10% relative to the cross-sectional area prior to treatment; an improvement in bile flow of at least 10% relative to the bile flow prior to treatment; a reduction in tumor volume of at least 10% relative to the tumor volume prior to treatment.

[0445] FIG. 28is a flowchart listing the steps involved in one embodiment of a method of tissue ablation in the bile duct. In step 2801, endoscopic retrograde cholangiopancreatography (ERCP) is performed. Next in step 2802, the bile duct is cannulated with a cannula and a guidewire is placed therein. In step 2803, the length of the bile duct segment to be ablated is measured. This length is then entered into the controller of the ablation system in step 2804 to determine the amount of ablation therapy to be delivered. In another embodiment, the length is used to select a catheter of appropriate ablation segment length. The catheter of the ablation system is then passed over the guidewire through the ERCP channel. The catheter includes a first positioning element, a second positioning element distal to the first positioning element, and a plurality of delivery ports between the first and second positioning elements on the catheter. In step 2805, the catheter is passed through the ERCP channel such that the second first positioning element (balloon) is placed distal to the bile duct to be ablated and the first positioning element (balloon) is placed proximal to the bile duct to be ablated. In step 2806, both balloons are inflated to a set pressure PI and the diameter of the bile duct is measured using the diameter of either balloon or the average of the diameters of both balloons. In 2807, the measured diameter of the bile duct is entered into the controller, either manually or automatically, and used to calculate the surface area of the bile duct to be ablated. Thereafter, in 2808, one or more cycles of steam are delivered to the bile duct through one or more of the steam delivery ports to ablate the bile duct tissue at a temperature range of 90 to 100 °C. In one embodiment, in 2809, the balloon pressure is maintained at a pressure P2 greater than or equal to PI during delivery of the ablation agent. Optionally, in 2810, between ablation cycles, the balloons are deflated to a pressure P3 less than or equal to PI. In step 2811, the endoscope and catheter are removed after completion of the ablation.

[0446] Bronchial ablation

[0447] With respect to lung function, there are four lung volumes and four lung capacities. Lung capacities are made up of two or more lung volumes. The lung volumes are tidal volume (VT), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and residual volume (RV). The four lung capacities are total lung capacity (TLC), inspiratory capacity (IC), functional residual capacity (FRC), and vital capacity. Measurement of one breath diffusing capacity of carbon monoxide (DLCO) is a quick and safe means of assessing restrictive and obstructive lung disease. Arterial blood gas (ABG) is a useful measurement method for lung function testing in selected patients. The primary role of measuring ABG in healthy and stable individuals is to confirm hypoventilation when hypoventilation is suspected based on history, such as respiratory muscle weakness or advanced COPD. Spirometry includes pulmonary mechanics tests such as forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow (FEF) values, forced inspiratory flow (FIF), and maximal voluntary ventilation (MVV). Measuring pulmonary mechanics assesses the ability of the lungs to move large amounts of air quickly through the airways to identify airway obstruction.

[0448] In various embodiments, the ablation therapy provided by the steam ablation system of the present specification is delivered to achieve the following treatment endpoints for lung ablation: maintaining tissue temperature at 100°C or less; reducing TLC (defined as the volume of the lungs at maximum inflation) by at least 5% relative to pre-treatment TLC; increasing VT (defined as the amount of air that flows into or out of the lungs during quiet breathing) by at least 5% relative to pre-treatment VT; reducing RV (defined as the amount of air remaining in the lungs after maximum exhalation) by 5% relative to pre-treatment RV; increasing ERV (defined as the maximum amount of air exhaled from the end of expiration) by 5% relative to pre-treatment ERV; increasing IRV (defined as the maximum volume that can be inhaled from the end of inspiration) by at least 5% relative to pre-treatment IRV; increasing IC by at least 5% relative to pre-treatment IC; increasing inspiratory vital capacity (IVC) by at least 5% relative to pre-treatment IVC, inspiratory vital capacity being defined as the maximum amount of air inhaled from the maximum point of exhalation; increasing VC (defined as the amount of air exhaled after the deepest inspiration) by at least 5% relative to pre-treatment VC; reducing FRC (defined as the volume of the lungs at the end of expiration) by at least 5% relative to pre-treatment FRC; reducing RV by at least 5% relative to pre-treatment RV; reducing V A by at least 5% relative to pre-treatment V A by at least 5% relative to pre-treatment V L by at least 5% relative to pre-treatment V L) at least 5% relative to pre-treatment DLCO; an increase in partial pressure of dissolved oxygen in plasma (PaO2) of at least 2% and / or a decrease in partial pressure of dissolved carbon dioxide in plasma (PaCO2) of at least 1% relative to pre-treatment PaO2 and PaCO2 levels; an increase in any of the vital capacity measurements of at least 5% relative to pre-treatment vital capacity measurements; an increase in forced vital capacity (FVC, defined as the volume of air expelled during a forced expiration) of at least 5% relative to pre-treatment FVC; an increase in forced expiratory volume in time (FEV t ) of at least 5% over time, forced expiratory volume in time defined as the amount of air expelled during a forced expiration in the first t seconds; an increase in FEV t 1 of at least 5% relative to pre-treatment FEV1; an increase in FEF of at least 5% relative to pre-treatment FEF; an increase in FEF max (defined as the maximum instantaneous flow rate reached during the FVC maneuver) of at least 5% relative to pre-treatment FEF max ; an increase in FIF of at least 5% relative to pre-treatment FIF; an increase in peak expiratory flow (PEF) of at least 5% relative to pre-treatment PEF, peak expiratory flow defined as the highest forced expiratory flow rate measured with a peak flow meter; an increase in MVV (defined as the amount of air expelled during a repeated maximal effort over a specified time period) of at least 5% relative to pre-treatment MVV.

[0449] FIG. 29A is a flow chart illustrating a bronchial alveolar tissue ablation method according to an embodiment of the present specification. Referring to FIG. 29A , a first step 2901 includes inserting a bronchoscope into a bronchus of a patient. Next, in step 2902, a catheter of an ablation device is passed through the bronchoscope, where the catheter includes a hollow shaft through which an ablative agent can pass, at least one positioning element, and at least one infusion port for delivering the ablative agent. In one embodiment, the ablation device includes a controller including a microprocessor for controlling delivery of the ablative agent. The catheter is inserted into the bronchoscope such that the positioning element is positioned in the bronchus connected to a large bubble cavity including bronchial tissue to be ablated. In step 2903, the positioning element is deployed such that it contacts a portion of the bronchus, and the catheter and infusion port are positioned near the large bubble cavity. In one embodiment, the bronchoscope is used as a fixed point to help position the catheter and infusion port within the large bubble cavity. Finally, in step 2904, the ablative agent is delivered through the infusion port to ablate the bronchial tissue.

[0450] FIG. 29B is a flow chart illustrating a bronchial tissue ablation method according to another embodiment of the present specification. Referring to FIG. 29BThe first step 2911 includes inserting a bronchoscope into the bronchus of a patient. Next, in step 2912, a catheter of an ablation device is passed through the bronchoscope, where the catheter includes a hollow shaft through which an ablative agent can pass, at least one first positioning element, at least one second positioning element distal to the at least one first positioning element, and at least one infusion port for delivering the ablative agent. In one embodiment, the ablation device includes a controller including a microprocessor for controlling delivery of the ablative agent. The catheter is inserted into the bronchoscope such that the first positioning element is positioned in the bronchus proximal to bronchial tissue to be ablated and the second positioning element is positioned distal to the bronchial tissue to be ablated. In step 2913, the positioning elements are deployed to contact the proximal and distal bronchi of the tissue to be ablated and the catheter and infusion port are positioned in proximity to the tissue to be ablated. Finally, in step 2914, the ablative agent is delivered through the infusion port to ablate the bronchial tissue.

[0451] Bronchial thermal shaping

[0452] FIG. 30A A cross-sectional view of a catheter 3005 for performing bronchial thermal molding in accordance with embodiments of the present specification is shown. The catheter 3005 includes an elongated body 3010 having a proximal end and a distal end, and an inflatable multi-layer balloon 3015 at the distal end. In some embodiments, the elongated body 3010 has first, second, and third lumens 3012, 3013, 3014.

[0453] The first lumen 3012 allows air to be pumped from the proximal end into the balloon 3015 for inflation. The second lumen 3013 houses a heating element 3020, which can be a flexible heating chamber having a plurality of RF electrodes. Saline / water is allowed to be pumped from the proximal end into the second lumen 3013 to enter the heating element 3020 for conversion into steam. The third lumen 3014 allows saline / water to flow out from the proximal end.

[0454] The multi-layer balloon 3015 includes an outer and inner balloon layer fused together. A plurality of fluid channels or pathways 3022 are defined and sandwiched between the outer and inner layers. The channels 3022 are in fluid communication with the second and third lumens 3013, 3014 such that steam generated in the second lumen 3013 is circulated through the channels 3022 and out of the catheter through the third lumen 3014. During operation, the balloon 3015 is inflated to expand to contact the target tissue and steam is allowed to be circulated through the channels 3022 to create a deep burn in the target tissue without scarring. This results in the steam being spread discontinuously over the tissue area in a controlled and circulatable manner.

[0455] In various embodiments, the channels 3022 are configured in a variety of patterns (e.g., but not limited to, wavy, a series of linear shapes, sinusoidal, square wave) such that the circulating steam creates ablation in the vicinity of the regions of the channels 3022, while the remaining regions of the balloon 3015 (i.e., regions without channels 3022) are free of any ablation. In some embodiments, the balloon 3022 is actively air cooled to control the amount of ablated tissue. In various embodiments, the catheter 3005 has a variety of applications in nerve or muscle ablation in hollow organs where circumferential ablation is not desired, such as in PV (Pulmonary Vein) ablation (cardiac), renal denervation (hypertension), and hepatic vein ablation (diabetes). In an exemplary application of PV ablation, the channels 3022 create an ablation pattern in the PV sufficient to block the conduction of electrical activity from the PV to the left atrium (LA) without causing significant stenosis in the PV, where the length of the circumferential ablation pattern is greater than the circumference of the PV in the vicinity of the ablation. In some embodiments, the distance between two adjacent circumferential ablation patterns is greater than twice the thickness of the PV.

[0456] FIG. 30B A variety of patterns of the channels 3022 according to various embodiments of the present specification are shown. The figure shows first, second, third, fourth, fifth, sixth, and seventh exemplary patterns 3031, 3032, 3033, 3034, 3035, 3036, 3037. For each pattern, a first path 3040 shows the direction of flow of steam, while a second path 3045 shows the direction of water / saline outflow. The pattern of the channels 3022 determines the ablation pattern.

[0457] FIG. 30C A workflow of performing a bronchial thermal shaping procedure using the catheter 3005 according to embodiments of the present specification is shown. At step 3050, an endoscope tube 3052 is inserted into the patient's lung to be positioned in the vicinity of a target tissue region for ablation. At step 3055, the catheter 3005 is inserted through the working channel of the endoscope 3052 such that the balloon 3015 is positioned at the target tissue region. Thereafter, at step 3060, the balloon 3015 is inflated with air such that the balloon 3015 contacts the target tissue region. Steam now flows through the patterned channels 3022 of the balloon to ablate the target tissue region.

[0458] Lung volume reduction

[0459] FIG. 31A A lung volume reduction (LVR) catheter 3105 according to embodiments of the present specification is shown, FIG. 31B The LVR catheter 3105 is shown deployed through an endoscope / bronchoscope 3110. Now referring to FIG. 31A 、 31BThe catheter 3105 includes an elongated shaft 3115 having a proximal end and a distal end. The distal end has at least one vapor delivery port 3120 and a plurality of suction ports 3125. A positioning element 3122 is located proximate to the at least one vapor delivery port 3120. In some embodiments, the positioning element 3122 is an inflatable balloon.

[0460] In some embodiments, the elongated shaft 3115 has first and second lumens 3130, 3132 extending from the proximal end to the distal end. The first lumen 3130 houses a heating element 3135, such as a flexible heating chamber including a plurality of RF electrodes of the present specification. Saline / water enters the proximal end to the heating element 3135, where it is converted to vapor for delivery through the at least one vapor delivery port 3120. The second lumen 3132 is in fluid communication with the plurality of suction ports 3125. During operation, vapor is delivered through the at least one vapor delivery port 3120 and air is drawn through the plurality of suction ports 3125, thereby creating a thermal energy cycle between the vapor delivery port 3120 and the suction port 3125. In one embodiment, a third lumen (not shown) allows air to be pumped into the balloon 3122 for inflation. FIG. 31B A catheter 3105 is shown deployed through a working channel of an endoscope 3110.

[0461] In some embodiments, the at least one vapor delivery port 3120 is at least 1 cm from the nearest one of the plurality of suction ports 3125.

[0462] FIG. 31C A workflow for performing lung volume reduction using the catheter 3105 according to one embodiment of the present specification is shown. In step 3150, a diseased region is identified for ablation therapy. In step 3152, the bronchoscope 3110 is positioned in an airway of the diseased region. In step 3154, the catheter 3105 is deployed through a working channel of the bronchoscope 3110 such that the catheter 3105 is located proximate to the diseased region. In step 3156, the balloon 3122 is inflated, vapor is delivered to the diseased region (through the vapor delivery port 3120) and air is drawn through the suction ports 3125 for a predetermined period of time, such as 3 to 10 seconds (depending on the quality of the diseased region).

[0463] FIG. 32A A needle catheter 3200 according to one embodiment is shown incorporating FIG. 1A to 1D a flexible heating chamber 130. FIG. 32B A needle catheter 3220 according to one embodiment is shown incorporating two flexible heating chambers 130. Reference is now made to FIG. 32A and 32B, each catheter 3200, 3220 includes an elongated body 3205, 3225 having a proximal end and a distal end. Each body 3205, 3225 has a lumen along its length and at least one needle 3210, 3230 at its distal end. In some embodiments, the needle is retractable. In one embodiment, at least one infusion port 3215, 3235 is located near the proximal end of the needle 3210, 3230, or on the needle 3210, 3230, which can be hollow. In various embodiments, the at least one infusion port 3215, 3235 is located in a range of 1 mm to 50 cm from the heating chamber(s) 130. In various embodiments, the needle catheter 3200, 3220 includes any of the needle embodiments discussed in this specification. At least one heating chamber 130 is incorporated in the catheter 3200, 3220, near the distal end of the body 3205, 3225. FIG. 32A Embodiments of FIG. 32B Embodiments of FIG. 32B , a water pump 3240 coupled to the proximal end of the body 3225 supplies water / saline through the lumen 3226 in the catheter body 3225 to the proximal end of the heating chamber 130. An RF generator 3245 provides electrical current to a plurality of electrodes (e.g., electrodes 136, 138) included in the heating chamber 130, which causes the electrodes to generate heat, where the heat is transferred to the water / saline to convert the water / saline to steam, which is then delivered through the infusion port 3235 to ablate target tissue.

[0464] In some embodiments, the catheter 3200, 3220 can optionally include at least one positioning element, such as an inflatable balloon, at the distal end of the body 3205, 3225.

[0465] In use, the pump 3240 delivers water / saline to the proximal end of the heating chamber 130 while the RF generator 3245 causes the electrodes to heat and vaporize the water / saline flowing through the heating chamber 130. The generated steam is expelled through the at least one port 3235. The flexible heating chamber 130 imparts improved flexibility and maneuverability to the catheter 3200, 3220, allowing the physician to better position the catheter 3200, 3220 when performing needle ablation procedures.

[0466] FIG. 32C is shown using FIG. 32A and 32BA flowchart of one embodiment of a method of ablating tissue with the needle catheter 3200, 3220. In a first step 3232, the catheter is inserted such that at least one positioning element is positioned in the vicinity of tissue to be ablated. The next step 3234 includes extending a needle through the catheter such that at least one infusion port is positioned in the vicinity of the tissue. At step 3236, water / saline is provided to the heating chamber (in some embodiments, to more than one heating chamber) by operating a water pump. At step 3238, an RF generator is used to provide current to the electrodes of the heating chamber to convert the water / saline to steam that exits the infusion port, thereby ablating the tissue. In another embodiment, the device does not include a positioning element, and the method does not include a step of positioning the positioning element in the vicinity of tissue to be ablated.

[0467] The above examples are merely illustrative of the many applications of the system of the present application. Although only a few embodiments of the present application have been described herein, it should be understood that the present application can be put into practice with many other embodiments and presently known or future developed equivalents. Therefore, the foregoing examples and embodiments are to be considered as illustrative rather than as limiting, and that the scope of the present application is to be determined by the following claims.

[0468] Therefore, the foregoing examples and embodiments are to be considered as illustrative rather than as limiting, and that the scope of the present application is to be determined by the following claims.

Claims

1. An ablation system, comprising: The catheter includes: A slender body, with a proximal end and a distal end; A flexible heating chamber is located in an inner cavity within an elongated body, wherein the flexible heating chamber includes electrodes configured to receive current and generate heat and configured to generate hot steam upon exposure to a fluid, wherein the electrodes include a first electrode array having a first polarity and a second electrode array having a second polarity opposite to the first polarity, and wherein a plurality of electrode elements define each of the first electrode array and the second electrode array, and wherein the electrode elements intersect each other to define a space in which a fluid flows and evaporates; Proximal and distal positioning elements are attached to an elongated body, wherein each of the proximal and distal positioning elements includes a compressible disk configured to expand upon deployment, and wherein surface areas of the proximal and distal positioning elements include a plurality of spaces sufficient to allow hot steam to flow out of the treatment space at 1% to 80% of the hot steam input flow rate. and Multiple ports are located on the elongated body and between the proximal and distal positioning elements, and are adapted to release hot vapor to the outside of the conduit; A pump configured to pump fluid through an internal cavity into a flexible heating chamber; and The generator is configured to supply current to the electrodes.

2. The ablation system of claim 1, wherein the conduit further comprises a filter adapted to provide back pressure to the hot steam.

3. The ablation system according to claim 2, wherein the filter comprises micropores.

4. The ablation system of claim 2, wherein the filter is configured to restrict the flow of hot vapor back into the conduit or upstream within the conduit.

5. The ablation system of claim 2, wherein the filter comprises a thin porous metal located near one or more of the plurality of ports.

6. The ablation system of claim 1, wherein one of the plurality of ports includes a one-way valve adapted to allow hot vapor to flow out of the port but not back into the conduit.

7. The ablation system according to claim 1, wherein the flexible heating chamber of the catheter is positioned at a distance of 1 mm to 50 cm from one of the plurality of ports.

8. The ablation system of claim 1, wherein the electrodes of the flexible heating chamber are folded back and forth to increase the contact area between the electrode surface and the fluid.

9. The ablation system according to claim 1, wherein the electrode elements intersect each other such that a cathode element is followed by an anode element, an anode element is followed by a cathode element, a cathode element is followed by an anode element, and so on, wherein the space separates each cathode and anode element.

10. The ablation system according to claim 9, wherein, The space between the cathode and the anode adjacent to the cathode is 0.01 mm to 2 mm.

11. The ablation system of claim 1, wherein the volume defined by the expanded proximal positioning element and the expanded distal positioning element is in the range of 3 cubic centimeters to 450 cubic centimeters.

12. The ablation system of claim 11, wherein at least one of the proximal positioning element and the distal positioning element is configured to undergo physical modification or deformation when the pressure within the treatment space increases to more than 10% of the baseline pressure.

13. The ablation system of claim 11, wherein at least one of the proximal positioning element and the distal positioning element is configured to undergo physical modification or deformation when heated steam is introduced into the treatment space, thereby increasing the amount of heated steam flowing out of the treatment space over time.

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