Devices and systems for reducing fluid volume when using fluid to access a body lumen

Abstract

Medical devices and methods are disclosed. An exemplary medical device for accessing a body lumen along a bile duct and / or pancreatic duct can include an elongate member having a distal end and a proximal end. The medical device may be connected to a system configured to supply pressurized fluid to the medical device. The system configured to supply pressurized fluid to the medical device can be configured to supply pressurized fluid at an initial first rate that attenuates to a second rate to facilitate cannulation of one or more of the bile duct and pancreatic duct while reducing the fluid supplied during the procedure.

Description

Technical Field

[0001] The present disclosure relates to medical devices and methods for manufacturing and using these medical devices. More specifically, the present disclosure relates to medical devices for accessing a body lumen along a bile duct and / or a pancreatic duct.

Background Art

[0002] For medical applications, such as endoscopic procedures, a wide variety of in vivo medical devices have been developed. Some of these devices include guidewires, catheters, catheter systems, and endoscopic instruments, among others. These devices are manufactured by any one of a variety of different manufacturing methods and may be used according to any one of a variety of methods. Each of the known medical devices and methods has specific advantages and disadvantages. There is always a need to provide alternative medical devices and alternative methods for manufacturing and using medical devices.

Summary of the Invention

[0003] The present disclosure provides alternatives for the design, materials, manufacturing methods, and use of medical devices and medical systems. An exemplary medical device for accessing a target body lumen includes a fluid accumulator having a proximal end configured to receive fluid from a pressurized gas source and a second end, a flexible elongate tube having a distal end configured to be directed toward the proximal end and an opening of the body lumen, a lumen extending from the distal end of the flexible elongate tube toward the proximal end of the flexible elongate tube and selectively communicating with the second end of the fluid accumulator, and a switch configured to adjust the communication between the fluid accumulator and the lumen upon actuation of the switch.

[0004] Instead of, or in addition to, any of the above examples, the switch is configured to automatically withdraw fluid from the distal end of the lumen at a first rate at a first time and at a second rate at a second time after the first time, the first rate being faster than the second rate.

[0005] Instead of, or in addition to, any of the above examples, the switch is connected to a valve that selectively blocks the flow of fluid downstream of the fluid accumulator and upstream of the distal end of the lumen.

[0006] Instead of, or in addition to, any of the above examples, the switch is mechanically connected to the valve. Instead of, or in addition to, any of the above examples, a first actuation of the switch is configured to communicate the fluid accumulator with the lumen, and a second actuation of the switch is configured to block the flow of fluid between the fluid accumulator and the lumen.

[0007] Instead of, or in addition to, any of the above examples, the fluid accumulator is a coil of tubing. Instead of, or in addition to, any of the above examples, the medical device may further include a first tube portion extending between the fluid accumulator and the switch, and a second tube portion extending between the switch and a third tube portion, the third tube portion including a flexible elongate tube.

[0008] Instead of, or in addition to, any of the above examples, the medical device may further include a fluid source lumen extending from the fluid accumulator and configured to communicate with a fluid source, and a flow restrictor disposed along the fluid source lumen.

[0009] An exemplary system may include a fluid accumulator and a sphincterotomy knife in communication with the fluid accumulator. The fluid accumulator is upstream of the sphincterotomy knife and is configured to store pressurized fluid for selectively discharging through the distal end of the sphincterotomy knife at an initial first velocity, and the first velocity decays over time to a second velocity.

[0010] Instead of, or in addition to, any of the above examples, the system may further include a pressurized fluid source upstream of the fluid accumulator and in communication with the fluid accumulator to supply pressurized fluid to the fluid accumulator.

[0011] Instead of, or in addition to, any of the above examples, the second velocity is based on the fluid flow rate of the fluid exiting the pressurized fluid source. Instead of, or in addition to, any of the above examples, the system may further include a flow restrictor disposed between the pressurized fluid source and the fluid accumulator to restrict the flow from the pressurized fluid source to the fluid accumulator.

[0012] Instead of, or in addition to, any of the above examples, the system may further include a valve upstream of the sphincterotomy knife and downstream of the fluid accumulator, and the valve is configured to regulate the flow of fluid from the fluid accumulator to the sphincterotomy knife.

[0013] Instead of, or in addition to, any of the above examples, the system may further include a switch in communication with the valve, and the switch is configured to be actuated to switch the valve between a closed position where the flow of fluid between the fluid accumulator and the sphincterotomy knife is blocked and an open position where fluid flows between the fluid accumulator and the sphincterotomy knife.

[0014] An exemplary method of accessing a target body lumen may include extending a long tube having a distal end and a lumen through a working channel of an endoscope extending within a subject, orienting the distal end of the long tube toward an opening of the body lumen, and flowing fluid from a fluid source through the lumen and out of the distal end of the long tube toward the opening of the body lumen. Flowing the fluid out of the distal end of the long tube through the lumen from the fluid source may include initially outputting the fluid from the distal end of the long tube at a first predetermined rate, where the first predetermined rate automatically decays to a second predetermined rate that is non-zero over time.

[0015] Alternatively or in addition to any of the above examples, the first predetermined rate is set to transition the opening of the body lumen from a closed state to an open state. Alternatively or in addition to any of the above examples, the non-zero second predetermined rate is set such that once the opening is opened, it remains open.

[0016] Alternatively or in addition to any of the above examples, the non-zero second predetermined rate is maintained for a period longer than the period during which the fluid is output at the first predetermined rate. Alternatively or in addition to any of the above examples, the method may further include opening a valve to allow fluid to flow from the fluid source through the lumen and out of the distal end of the long tube.

[0017] Alternatively or in addition to any of the above examples, the method may further include closing a valve to accumulate fluid from the fluid source within a fluid accumulator that selectively communicates with the lumen.

[0018] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure can be more fully understood by considering the following detailed description in connection with the accompanying drawings.

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[0020] The present disclosure is capable of accepting various modifications and alternative forms, and details thereof are shown in the drawings by way of example and will be described in detail. However, it should be understood that the intention is not to limit the present disclosure to the specific embodiments described. In contrast, the intention is directed to all modifications, equivalents, and alternatives falling within the technical idea and scope of the present disclosure.

Best Mode for Carrying Out the Invention

[0021] Unless different definitions are provided in the claims or other parts of this specification, the terms defined below shall apply where these definitions are applicable. The configurations of the present disclosure may be specifically described with reference to medical devices and systems (e.g., endoscopic devices, accessory tools, and / or guidewires inserted through or near or through the papilla of Vater such as duodenoscopes or endoscopes) for selective access to the common bile duct (CBD) or pancreatic duct (PD), alignment with the CBD or PD, and / or cannulation of the CBD or PD during an endoscopic retrograde cholangiopancreatography (ERCP) procedure. However, such medical devices and systems may be used in various medical procedures that require navigating one or more accessory tools through anatomical structures of tubes, lumens, blood vessels, or body lumens, including, for example, image-guided therapy, balloon angioplasty / angiography procedures, thrombolysis procedures, urological or gynecological procedures, etc. It should be understood that the disclosed medical devices and systems may be inserted via different access points and approaches, for example, percutaneously, endoscopically, laparoscopically, or some combination thereof.

[0022] Regardless of whether explicitly indicated, all numerical values are assumed to be modified in this specification by the term "about." In the context of numerical values, the term "about" generally indicates a range of numbers that would be considered by one of ordinary skill in the art to be equivalent (e.g., having the same function or result) to the recited value. In many cases, the term "about" may include numbers rounded to the nearest significant digit. Other uses of the term "about" (e.g., in contexts other than numerical values) may be understood from the context of this specification and may be assumed to have their ordinary customary definitions consistent with the context of this specification, unless otherwise indicated.

[0023] The recitation of numerical ranges by endpoints includes all numbers within that range including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although some preferred dimensions, ranges and / or values for various components, features and / or specifications are disclosed, one of ordinary skill in the art, being stimulated by the present disclosure, will understand that desirable dimensions, ranges and / or values may deviate from those explicitly disclosed.

[0024] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally used in the sense including “and / or” unless the content clearly dictates otherwise. Note that for ease of understanding, certain features of the present disclosure may be described in the singular, even though those features may be repeated or plural within the disclosed embodiments. Each instance of a feature includes and / or may be encompassed by a singular disclosure, unless the contrary is explicitly stated. For brevity and clarity, not all elements of the present disclosure are necessarily shown in each drawing or discussed in detail below. However, it will be understood that the following discussion may be equally applicable to any and / or all of two or more components, unless the contrary is explicitly stated. Further, for clarity, not all instances of some elements or features are shown in each drawing.

[0025] References to "an embodiment", "some embodiments", "other embodiments", etc. in this specification are to be noted as indicating that the described embodiments may include certain features, structures, or characteristics, but not all embodiments necessarily include the certain features, structures, or characteristics. Further, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in relation to an embodiment, unless explicitly stated to the contrary or clearly stated otherwise, it would be within the knowledge of those skilled in the art to bring about the particular feature, structure, or characteristic in relation to other embodiments. That is, the various individual elements described below can be combined or arranged with each other to form other additional embodiments or to complement and / or reinforce the described embodiments as would be understood by those skilled in the art, even if not explicitly shown in a particular combination.

[0026] For clarity, a particular identification numbering system (e.g., first, second, third, fourth, etc.) may be used throughout the description and / or claims to name and / or distinguish the various described and / or claimed features. It is to be understood that the numbering system is not intended to be limiting and is merely illustrative. In some embodiments, changes and departures from the previously used numbering system may be made for the sake of brevity and clarity. That is, a feature identified as a "first" element may later be shown as a "second" element, a "third" element, etc., or may be completely omitted, and / or a different feature may be shown as the "first" element. The meaning and / or name in each instance will be apparent to those skilled in the art.

[0027] The detailed description is intended to be illustrative and not limiting of the disclosure. Those skilled in the art will recognize that the various elements described can be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description shows exemplary embodiments of the disclosure.

[0028] As discussed herein, the distal tip of a medical device desirably is flexible to effectively move within a body lumen. For example, a flexible distal tip of a medical device can facilitate navigation through narrow passages such as the Vaterian papilla and / or other ducts. In some instances, a flexible distal tip of a medical device can be positioned proximate to a structure such as a lesion, calculus, or other deposit and / or within which such a structure is located, and can facilitate guiding the medical device into the target body lumen.

[0029] In some instances, the devices and methods disclosed herein can be useful for other purposes, among other things, for diagnostic or therapeutic procedures in the bile duct and / or pancreatic duct. Access to the biliary-pancreatic system as facilitated by the devices disclosed herein can be necessary for diagnosing and / or treating a variety of conditions including, but not limited to, tumors, gallstones, infections, sclerosis, and pseudocysts. The devices disclosed herein also can be useful for navigation in other parts of the body (e.g., the cardiovascular system, etc.).

[0030] Endoscopic retrograde cholangiopancreatography (ERCP) can be used, for example, to diagnose and treat conditions of the common bile duct including, but not limited to, gallstones, inflammatory strictures, leaks (e.g., due to trauma, surgery, etc.), cancer, and / or other conditions. In an ERCP procedure, a physician can visualize the inside of the stomach and / or duodenum using an endoscope. During the procedure, the area can be observed by X-ray by injecting a dye into the biliary system and / or the ducts of the pancreas. These procedures can require gaining and maintaining access to the Vaterian papilla, the common bile duct, and / or the pancreatic duct, which can be technically difficult, require extensive training and practice to master, and can require one or more expensive tools to perform.

[0031] During an ERCP procedure, several steps may be performed while the subject is sedated and / or anesthetized. For example, the endoscope may enter the stomach through the esophagus from the mouth, pass through the pylorus into the duodenum, and be inserted to a position near or at the ampulla of Vater (also referred to as the ampulla of Vater), which is the opening of the common bile duct and pancreatic duct. Due to the shape of the papilla and the angle at which the common bile duct and pancreatic duct contact the duodenal wall, the distal end of the endoscope is generally positioned just in front of the papilla. Since the endoscope is positioned beyond the papilla, the endoscope typically used in these procedures is a side-view endoscope. The side-view function can provide imaging along the side of the distal end rather than axially at the end of the endoscope. With such an orientation, even when the distal end of the endoscope extends beyond the opening, the physician may be able to obtain an image of the inner wall of the duodenum where the ampulla of Vater is located.

[0032] In some cases, a fluid (e.g., a compressible gas, air, nitrogen, carbon dioxide, or other suitable fluid) can be delivered to the opening of the subject's body lumen (e.g., the ampulla of Vater) via a catheter, an endoscope (e.g., inserted into the subject as described above or inserted by another method), an endoscopic accessory device, or other suitable long medical device. By applying the fluid to the opening, it is possible to facilitate the identification and / or access to the body lumen by at least partially dilating the opening with the fluid before and / or during the delivery of a catheter, endoscope, guidewire, etc. to the opening of the body lumen or a target anatomical structure or tissue distal thereto (e.g., a duct or other suitable structure or tissue). The fluid flow may be used to identify and / or dilate the opening to the lumen, but it is desirable to limit or reduce the total amount of fluid delivered to the subject's body lumen, space, or cavity during the procedure.

[0033] The fluid can be delivered to the opening of the body lumen via a catheter, an endoscope, or the like, by any suitable method. Some exemplary techniques and systems for delivering a fluid to the opening of a body lumen are described in U.S. Patent Application Publication No. 2019 / 0380565, filed on June 13, 2019, and titled DEVICES, SYSTEMS AND METHOD FOR ACCESSING A BODY LUMEN, which is incorporated herein by reference for any and all purposes.

[0034] A system for delivering a compressible fluid to the opening of a body lumen will deliver a large amount of gas to a sealed cavity of the subject. In some cases, it may take a long time for the subject's body to fully absorb the gas. Depending on the volume of the gas, it may cause pain, discomfort, and / or abnormal sensations to the subject until the gas is fully absorbed or otherwise discharged. Depending on the volume of the fluid supplied to the subject, it may cause barotrauma, destruction, rupture of tissue, and / or other undesirable effects on the subject's body tissue.

[0035] Therefore, it is desirable to provide a system that can promote opening and maintaining the body lumen open while restricting the amount of fluid supplied to the subject. Such a system may be configured to deliver a fluid with a high initial flow rate to the subject to facilitate identification and / or dilation of the opening of the subject's body lumen, and then deliver a fluid with a lower flow rate to the subject to facilitate maintaining the body lumen open. Such a system can reduce or mitigate the amount of fluid required to open the body lumen and can maintain the body lumen open. Such a reduction in the total fluid volume provided to the body lumen can reduce the likelihood of causing tissue drying, destruction, and / or other damage that can be caused by using a high volume and / or high speed gas when expanding the tissue.

[0036] Referring to the figures, FIGS. 1 and 2 show selective cannula insertion during an ERCP procedure, which includes placing the distal portion of a medical device 22 (e.g., a duodenoscope, an endoscope, etc.) into the descending duodenum 18, and passing a guidewire 12 and / or an endoscope accessory device 14 through, toward, and / or through the body lumen, such as the major papilla 16 (e.g., the ampulla inlet) near the descending duodenum 18, via the medical device 22 to access the sphincter of Oddi complex 20. The guidewire 12 and the endoscope accessory device 14 can be advanced toward the major papilla 16 through the working channel 23 of the medical device 22. Further, the guidewire 12 and / or the endoscope accessory device 14 can be advanced toward and / or through the major papilla 16 into a desired one of the common bile duct 17, the pancreatic duct 19, and / or other suitable body lumens.

[0037] Accessing the papilla 16 can be difficult because the opening is small compared to the size (e.g., diameter) of many medical devices, because the opening is fully folded / closed, and / or because the opening may extend into the descending duodenum 18 at an angle that is difficult to visualize and / or access. Thus, a healthcare provider may need to manipulate the endoscope accessory device 14 and / or the guidewire 12 by manually rotating the medical device 22 and / or using an elevator within the distal end of the medical device 22 to better align or orient the medical device 22 and the endoscope accessory device 14 and / or the guidewire 12 with the opening of the papilla 16. Difficult cannula insertion procedures where a healthcare provider is unable to access the papillary sphincter within a specific time limit or after a certain number of attempts can lead to serious post-procedure complications such as post-ERCP pancreatitis (PEP).

[0038] As described above, when a healthcare provider accesses a body lumen (e.g., a duct such as a papilla) by operating a medical device toward or into the opening of the body lumen, a compressive force can be applied to the wall of the opening of the body lumen. Compression of the body lumen opening or the body lumen itself can cause buckling, such as can be described as the "accordion effect." When a medical device is inserted into the body lumen without the accordion effect, repeated insertion of the medical device and / or a guidewire or other instrument to open the body lumen and / or maintain the patency of the body lumen can cause irritation to body tissue due to friction.

[0039] Figure 3 shows an exemplary system 24 for accessing a body lumen without the need for contact from a medical device and for opening and maintaining the opening to the body lumen in an open state when disposing a medical device within the body lumen during and / or in another manner. In some cases, system 24 can include a medical device 22 having a flexible elongate tube 26 among other components.

[0040] Tube 26 can have a proximal end 26a and a distal end 26b. The distal end 26b of tube 26 can be configured to be oriented toward and / or pass through the opening of the body lumen. The proximal end 26a of tube 26 can be connected to, coupled to, or otherwise in communication with handle 28.

[0041] Wire filament 30 can extend along elongate tube 26 and can be energized for the purpose of cutting tissue within a subject. Wire filament 30 can have a proximal end (not shown) connected to an actuating portion 32 of handle 28 and a proximal portion that extends at least partially within tube 26. Wire filament 30 can also have a distal portion 34 that extends outside of elongate tube 26, and the distal end 36 of filament 30 can be connected to the distal end 26b of elongate tube 26.

[0042] The wire filament 30 may be received within the lumen of the tube 26 and may be configured to slide within the lumen, at least along the proximal portion of the filament 30. Optionally, the operating portion 32 of the handle 28 can be manipulated to slide the wire filament 30 along the tube 26 (e.g., within the lumen of the tube 26).

[0043] By sliding the wire filament 30, the distal end 26b of the elongate tube 26 can move in response to the sliding of the wire filament 30. Thus, the position of the distal end 26b of the elongate tube 26 can be controlled or adjusted by manipulating the operating portion 32 of the handle 28. In one embodiment, the operating portion 32 of the handle 28 can be manipulated to direct the distal end 26b of the tube 26 toward the opening of the body lumen.

[0044] Optionally, the wire filament 30 may be utilized to electrically cut, remove, and / or cauterize tissue of interest. Thus, the handle 28 or other suitable portion of the medical device 22 can include an electrical connection 38 for an energy source (e.g., a radiofrequency energy source, etc.) to supply energy to the wire filament 30 and facilitate tissue cutting. By manipulating the operating portion 32 of the handle 28 to apply tension to the wire filament 30 and adjust the position of the distal end 26b of the tube 26, the wire filament 30 can be spaced from the tube 26 and energized to facilitate cutting of tissue at the opening of the body lumen or tissue adjacent to the opening of the body lumen.

[0045] The medical device 22 can include one or more lumens extending from at least the proximal end 26a of the tube 26 to the distal end 26b of the tube 26. Although not essential, at least a portion of the one or more lumens may move with the distal end 26b of the tube 26 (e.g., toward the opening of the body lumen).

[0046] In some cases, the first lumen of one or more lumens of the elongate tube 26 can have a fluid connection for a pressurized fluid source 40 (e.g., a CO2 tank or a container of other suitable fluid) at its proximal end. The first lumen can be configured to apply fluid (e.g., gas) from the fluid source 40 to the opening of the target body lumen to open or at least partially open an opening for accessing the body lumen by the guide wire 12 and / or the elongate tube 26 without or substantially without the elongate tube 26 contacting the body lumen. When the body lumen opens or partially opens, the user can energize the wire filament 30 to cut or remove body tissue and further expand the opening.

[0047] The second lumen of one or more lumens can be configured to receive the guide wire 12. The second lumen can extend at least partially along the tube 26 from the distal end 26b of the tube 26 towards the proximal end 26a of the tube 26. In some cases, the guide wire 12 can extend proximally from the opening port 45 and / or distally from the distal opening at the distal end 26b of the tube 26. When disposed within the target body lumen, the tube 26 can be withdrawn from the guide wire 12, and the guide wire 12 can be used to guide the medical device 22 or other instrument to the target region within the target body lumen.

[0048] The opening port 45 can be disposed at the distal end of the handle 28, the proximal end 26b of the tube 26, and / or one or more other suitable locations. In some cases, the opening port 45 and the tube 26 can be configured to allow the guide wire 12 to be peeled off from the side of the tube 26 for rapid removal or replacement of the device, but this is not essential.

[0049] The third lumen of the one or more lumens may communicate with a contrast agent source and be configured to deliver a contrast agent to a target body lumen and / or associated tissue. The contrast agent may be supplied to the third lumen, for example, via a syringe attached to a luer connector on the handle 28 and / or via one or more other suitable connections. The contrast agent may be delivered into the body lumen and may be used, for example, to temporarily improve imaging of the inside of the body lumen by X-ray, fluoroscopy, computed tomography (CT), or magnetic resonance (MR) imaging, and ultrasound, among others.

[0050] Although not essential, a filter (e.g., a 0.1 microfilter and / or other suitable filter) within the tube 42 may communicate with the first lumen distal or downstream of the fluid source 40 and proximal or upstream of the first lumen. Optionally, a flow regulator 44 may be able to communicate with the first lumen and may be utilized to regulate the flow of fluid from the fluid source 40, through the filter (if included) within the tube 42, to or into the first lumen of the tube 26.

[0051] The flow regulator 44 may include a valve configured such that a user can change the flow rate and / or pressure of the fluid passing through the device 22. In some configurations, the flow regulator 44 may be, or may include, an on / off valve. In one embodiment, the flow regulator 44 may be, or may include, a trumpet valve.

[0052] For example, in the event that the pressure of the fluid becomes too high for the procedure or patient safety, such as due to an occlusion within the lumen or perhaps a failure of the regulator 44, a bleed hole and / or valve may be disposed upstream of the elongate tube 26 along the fluid path from the fluid source 40 to relieve the pressure from the system 24. The bleed hole may include a one-way valve that opens at a specific threshold of pressure and / or may have one or more other suitable configurations.

[0053] In some cases, the pressure of the fluid in the fluid source 40 may be higher than the desired pressure of the fluid in the accessory device 14. Thus, the fluid from the fluid source 40 can be supplied through the regulator 44 to reduce the fluid pressure in front of the pressure relief hole or valve. The regulator 44 and / or the relief valve can protect the subject and the accessory device 14 from the higher pressure of the fluid source 40 by adjusting the pressure in the regulator 44 downward or by setting a relief threshold for the relief hole or valve to release the fluid pressure when the pressure in the relief hole or valve exceeds the relief threshold.

[0054] In some cases, the pressure relief hole or valve may be disposed downstream of the flow regulator 44. In such a case, if the regulator 44 fails or is inaccurately set, the pressure relief valve can open to prevent an undesirably high pressure and / or high volume of fluid from entering the accessory device 14. A suitable range of fluid pressure for a system or device delivered from the downstream side of the regulator 44 and / or the relief valve may be, for example, from about 10 psi (69 kPa) to about 50 psi (345 kPa), and / or other suitable ranges of pressure values.

[0055] FIG. 4 shows an enlarged distal end of a system 24 that supplies fluid 46 to an opening 48 (e.g., an opening defined by the main papilla 16) of a body lumen 50 (e.g., a body lumen defined by the Oddi sphincter 20). Although not shown, the fluid 46 comes from a fluid source (e.g., fluid source 40 and / or other suitable fluid source) and exits from the distal end of the tube 26 at a constant or substantially constant velocity and / or pressure, thereby adjusting the opening 48 to an open state and maintaining the opening 48 in an open state.

[0056] To reduce the amount of fluid supplied to a subject during a procedure and the time the subject is exposed to high pressure and / or high flow rate fluid, system 24 may be configured to supply fluid to the subject in a non-constant flow. For example, system 24 may supply fluid to the subject at an initial flow rate or withdrawal rate and then reduce the flow rate or withdrawal rate of the fluid supplied to the subject until the flow reaches the desired flow rate or withdrawal rate of the fluid. In some cases, the desired flow rate or withdrawal rate of the fluid is the flow rate or withdrawal rate necessary to maintain the opening of the body lumen in an open state after initially using the fluid to adjust the opening from a closed state to an open state. Reducing the flow rate or withdrawal rate of the fluid supplied to the subject from a first flow rate or withdrawal rate to a lower second flow rate or withdrawal rate may be done in a linear manner, a stepwise manner, and / or one or more other suitable methods. FIGS. 5-10 illustrate systems, components, and methods for supplying fluid to a subject during a procedure at a flow rate or velocity that is reduced over time until a predetermined flow rate or velocity is reached.

[0057] FIG. 5 shows the configuration of system 24 set to supply fluid to a subject at a first flow rate or withdrawal rate (e.g., an initial flow rate or withdrawal rate), and the flow rate or withdrawal rate of the fluid supplied to the subject may decrease (e.g., decay) over time to a second flow rate or withdrawal rate. In some cases, the second flow rate or withdrawal rate may be at least partially based on the fluid flow rate or withdrawal rate of the fluid exiting the pressurized fluid source. The first flow rate or withdrawal rate may be greater than the second flow rate or withdrawal rate.

[0058] Starting from the proximal end of the system 24, the system 24 shown in FIG. 5 includes, among other components, one or more fluid sources 40 (e.g., cylinders or containers containing pressurized fluid), one or more cylinder pressure gauges 52 configured to provide an indication of the pressure within the one or more fluid sources 40, one or more pressure controllers 54 (e.g., pressure regulating knobs and / or other suitable pressure controllers) configured to control the pressure or flow rate (e.g., volumetric flow rate) of the fluid exiting from the one or more fluid sources 40, one or more outlet pressure gauges 56 configured to provide an indication of the pressure or flow rate of the fluid exiting from the one or more fluid sources 40 downstream of the one or more pressure controllers 54, a fluid source outlet tube 58, a pressurization system configured to receive fluid from the fluid source outlet tube 58 and including a flow limiter 62 and a fluid accumulator 64, an accumulator outlet tube 66 in communication with the outlet of the fluid accumulator 64 and configured to receive fluid from the fluid accumulator 64, a flow regulator in communication with the accumulator outlet tube 66 and configured to receive fluid from the accumulator outlet tube 66, and a flow regulator outlet tube 72 in communication with the flow regulator 44 and the connector 74 (e.g., a luer connector and / or other suitable type of connector) of the endoscopic accessory device 14 (e.g., a sphincterotome and / or other suitable accessory device) and configured to supply the fluid passing through the flow regulator 44 to the accessory device 14 to open and keep open the opening of the target body lumen. The lumen of the elongate tube 26 of the accessory device 14 may extend from the distal end of the elongate tube 26 towards the proximal end of the elongate tube 26 and selectively communicate with the fluid accumulator 64 through the connector 74 and via a flow valve 68 (e.g., within the housing as shown in the figure) to the flow regulator outlet tube 72.

[0059] Multiple tubes 58, 66, 72 are labeled in FIG. 5 and described above, but a single tube or two or more tubes may be utilized as needed. In some cases, the tubes of the system 24 may be combined to form a single lumen or multiple lumens through which fluid from the fluid source 40 passes through the accessory device 14 and reaches the subject.

[0060] The pressure controller 54 may be adjusted to control the pressure or flow rate of the fluid exiting from the fluid source 40. Optionally, if included, the fluid source pressure gauge 52 can display the pressure upstream of the pressure controller 54 (e.g., within the fluid source 40) or provide pressure indication in other ways. If included, the fluid source outlet pressure gauge 56 can display the pressure or flow rate of the fluid downstream of the pressure controller 54 (e.g., exiting the pressure controller 54) that is set by the pressure controller 54 and supplied to the pressurization system 60, or provide pressure or flow rate indication in other ways.

[0061] The pressurization system 60 may be configured to facilitate supplying the target fluid at a pressure or flow rate below the pressure or flow rate set by the pressure controller 54 and may include a flow restrictor 62 and a fluid accumulator 64. Optionally, the pressurization system 60 can include a housing that houses the flow restrictor 62, the fluid accumulator 64, and / or other suitable components of the pressurization system 60, but this is not essential. The flow restrictor 62 can be configured to narrow the fluid flow path and limit the flow rate of the fluid that is given an inlet pressure from the fluid source 40 and moves through the flow path. The flow restrictor 62 may be fixed or optionally variable. Other suitable flow restrictors 62 are also contemplated. Optionally, the flow restrictor 62 may be omitted.

[0062] The fluid accumulator 64 can have a proximal end configured to receive fluid from the pressurized fluid source 40 and a second end (e.g., a distal end). As shown in FIG. 5, the fluid accumulator 64 can be a cylinder configured to accumulate fluid when the flow regulator 44 is in a closed state. Without limitation, a coil of tubing, a length of tubing, one or more tanks, a chamber in series with the tubing or flow path of the fluid of the system 24, and / or adding a compressed fluid volume between the flow limiter 62 and the flow regulator 44 when the flow regulator 44 is in a closed state (e.g., configured to be filled with pressurized fluid), and other suitable types of fluid accumulators are envisioned that are configured to output pressurized fluid when the flow regulator 44 is switched to an open state, including other suitable volumes.

[0063] The fluid accumulator 64 can be any suitable type of fluid accumulator. In some cases, the fluid accumulator 64 can be a fixed volume. In such cases, pressurized fluid at a constant rate is supplied to the accumulator 64, and when the flow regulator 44 opens, the flow rate of the fluid supplied to the subject can decay linearly over time from an initial flow rate to a steady-state flow rate.

[0064] The flow regulator 44 can include a flow valve 68 and a switch actuator 70 (e.g., a switch). The flow valve 68 can be within the housing, as shown in the figure, and can be configured to regulate the flow through the accumulator outlet tube 66 to the flow regulator outlet tube 72 (e.g., regulate the flow through one or more lumens of the tubes 66, 72). The tubes 66, 72 and / or their lumens can be connected and / or in communication with the flow valve 68 in any suitable manner such that the operation of the flow valve 68 regulates the flow through the lumens of the tubes 66, 72.

[0065] The flow valve 68 may be any suitable type of valve that communicates with the flow path of pressurized fluid from the fluid source 40 to the attached device and is adjustable between an open state and a closed state. When the flow valve 68 is in the closed state, the fluid accumulator 64 can accumulate pressurized fluid for release under pressure when the flow valve 68 is adjusted to the open state or open position.

[0066] In some configurations, the flow valve may be an on / off valve. Additionally or alternatively, the flow valve 68 may be an adjustable valve having an off configuration that blocks the flow through the lumens of the tubes 66, 72 and an adjustable "on" configuration that allows different adjustable levels of flow through the lumens of the tubes 66, 72. In one exemplary configuration, the flow valve 68 may be or may include a trumpet valve, although this is not essential.

[0067] The switch or switch actuator 70 may be mechanically, electromechanically, and / or electrically connected to the flow valve 68 so that adjusting the switch actuator 70 can adjust the flow valve 68 between an open state and a closed state. In one embodiment, upon a first actuation of the switch actuator 70, the fluid accumulator 64 and the lumen of the attached device 14 may be communicated, and upon a second or subsequent actuation of the switch actuator 70, the flow of fluid between the fluid accumulator 64 and the lumen of the attached device 14 may be blocked.

[0068] The switch actuator 70 may be any suitable type of actuator configured to be adjusted to switch the state of the flow valve 68. As shown in FIG. 5, the switch actuator 70 may be a foot pedal. Alternatively or additionally, the switch actuator 70 may be a button, dial, knob, touch screen controller, on / off switch, and / or other suitable type of switch actuator 70.

[0069] During operation, system 24 may be utilized to accumulate or pressurize fluid within fluid accumulator 64 such that when switch actuator 70 is adjusted or actuated and flow valve 68 is adjusted from a closed state to an open state, pressurized fluid can be delivered to the subject at a relatively high flow rate through the lumen of accessory device 14 from fluid source 40 and fluid accumulator 64 at a relatively high exit velocity. The first flow rate may be determined by the source pressure set at pressure controller 54, which may be the maximum pressure achieved within fluid accumulator 64 when the flow valve is in the closed state. Thus, when fluid accumulator 64 is disposed downstream of flow restrictor 62, has a defined volume, and is pressurized by fluid from fluid source 40, the maximum value of the flow rate of fluid exiting fluid accumulator 64 can be determined by the first pressure within accumulator 64 and the inherent flow resistance of the flow path downstream of fluid accumulator 64. When flow valve 68 is in the open state, the fluid flow from fluid accumulator 64 exits fluid accumulator 64 faster than fluid enters fluid accumulator 64 due to flow restrictor 62 between fluid source 40 and fluid accumulator 64, and as a result, the initial relatively high flow rate and fluid exit velocity of fluid from distal end 26b of elongate tube 26 decreases over time until it reaches a steady-state flow rate or exit velocity (e.g., a second flow rate or velocity) determined by, among other factors, 1) the pressure set at pressure controller 54, and 2) the configuration of flow restrictor 62. The second flow rate or velocity can be considered the steady-state flow rate or velocity that occurs when fluid enters fluid accumulator 64 at the same velocity as when fluid exits fluid accumulator 64. Next, when flow valve 68 closes or begins to close, system 24 is reset and pressurized fluid refills fluid accumulator 64, and as a result, the process of supplying high-pressure or high-flow fluid to the subject can be repeated as needed.

[0070] The configuration of system 24 can be configured and / or adjusted to obtain a desired flow rate, velocity, or pressure of the fluid supplied to the subject over time. For example, the configuration (e.g., size, shape, etc.) of fluid accumulator 64, the fluid pressure set in pressure controller 54, and the configuration (e.g., size, shape, etc.) of flow restrictor 62 can be such that the peak flow rate (e.g., initial or first flow rate), the flow rate decay rate (e.g., the gradient from the peak flow rate to the steady-state flow rate), the ramp duration (e.g., the transition time from the peak pressure or flow rate to the steady-state pressure or flow rate), and / or the steady-state pressure or flow rate (e.g., second flow rate) can be configured or adjusted to be set to a desired level (e.g., a level sufficient to open an opening in the body lumen, maintain the opening in an open state, and supply fluid to the subject in an amount less than the desired amount, etc.). In some cases, among other factors, the value of the fluid pressure set in pressure controller 54 can determine the peak or first flow rate or egress velocity, the fluid pressure and / or flow rate set in the configurations of pressure controller 54 and flow restrictor 62 can determine the steady-state or second flow rate or egress velocity, and the size of fluid accumulator 64 and the characteristics of the fluid path downstream of accumulator 64 can determine the pressure or flow rate decay rate and / or the duration between the peak or first flow rate or egress velocity and the steady-state or second flow rate or egress velocity.

[0071] When activating or opening the flow valve 68, the system 24 shown in FIG. 5 delivers gas at a relatively high initial flow rate or exit fluid velocity from the accessory device 14 to facilitate expanding or otherwise opening the body lumen opening, and then automatically reduces the flow rate or exit velocity of the fluid delivered to the subject to a level sufficient to maintain the opening of the body lumen, enabling placement of one or more medical devices within the body lumen. Due to the reduction in flow rate, the total gas volume delivered to the subject during the procedure can be significantly lower compared to existing systems that deliver fluid to the subject for the purpose of opening the body lumen. The reduction in the total gas volume delivered to the subject can reduce the risks associated with inflating and pressurizing a closed or normally closed body lumen of the subject undergoing the procedure. Further, by reducing the fluid flow rate or pressure, the overall stress applied to the affected tissues and structures over the time the pressurized fluid is delivered to the subject may be reduced, and the risk of incidental effects such as tissue drying and / or other effects due to the tissue being exposed to a large volume of dry fluid expanding from the compression source may also be reduced.

[0072] FIG. 6 shows a further configuration of the system 24 that operates in a manner similar to the configuration of the system 24 described above with respect to FIG. 5. The configuration of the system 24 of FIG. 6 has a pressurization system 60 that includes a fluid source 40, a flow restrictor 62, and a fluid accumulator 64. In some cases, the pressurization system 60 can include a housing that houses the fluid source 40, the flow restrictor 62, the fluid accumulator 64, and / or one or more other suitable components of the pressurization system 60.

[0073] When the pressurization system 60 is configured as shown in FIG. 6, the pressurization system can have a releasable connection to the accumulator outlet tube 66. In such a configuration, the pressurization system 60 may be removed from the accumulator outlet tube 66 and reused for subsequent procedures on other subjects while allowing the tubes 66, 72, and the flow regulator 44 to be discarded.

[0074] Further, as shown in FIG. 6, the flow regulator 44 may be configured to be handheld. FIG. 5 shows a flow regulator 44 configured as a foot pedal, and FIG. 6 shows a handheld flow regulator 44, but the configuration of the system 24 shown in FIGS. 5 and 6 enables the use of a foot pedal flow regulator 44, a handheld flow regulator 44, and / or other appropriately configured flow regulators 44.

[0075] In one configuration of the handheld flow regulator 44, the flow valve 68 can include a plurality of positions 76 (e.g., gripping positions) configured to receive the user's finger when the flow valve 68 is gripped. Further, the switch actuator 70 may be configured as a button, trigger, and / or other appropriate actuator (as shown in FIG. 6) when the flow valve 68 is configured to be gripped by the user's hand. During operation, the user can grip the flow valve 68 such that the finger wraps around the flow valve 68 and can actuate the switch actuator 70 by pressing it with the thumb of the hand gripping the flow valve 68 or in one or more other appropriate ways that facilitate providing a desired flow of pressurized fluid to the subject, although other configurations are contemplated.

[0076] FIG. 7 is a schematic flow diagram of an exemplary technique 100 for accessing a body lumen of a subject. In some cases, the system 24 or a system similar to the system 24 described above may be utilized to access the body lumen of the subject. The technique 100 may be utilized to access the openings of other body lumens, but in one embodiment, the technique 100 may be utilized to access the major papilla of the subject to enter into the common bile duct and / or pancreatic duct.

[0077] Exemplary technique 100 may include extending a long tube of an accessory device (e.g., the long tube 26 of the accessory device 14 such as a sphincterotomy knife and / or other suitable long tube) through the working channel of an endoscope inserted into a target lumen (e.g., the lumen of the target duodenum and / or other suitable body lumen) (102). The endoscope may be inserted into the lumen using any suitable known technique. The long tube may be extended through the working channel of the endoscope before or after the endoscope is positioned within the target lumen, as needed.

[0078] The distal end of the long tube extending through the working channel of the endoscope may be directed towards the opening of the target body lumen (104). In some cases, after the endoscope is positioned in proximity to the opening of the body lumen, advancing the distal end of the long tube through the endoscope may automatically cause the distal end of the long tube to be directed towards the opening of the body lumen. For example, a visualization system associated with the endoscope may be utilized to position the opening of the distal end of the endoscope in proximity to the opening of the body lumen. Additionally, the endoscope may have a ramp-shaped body or other elevator-shaped body for guiding the long tube out from an opening within the endoscope such that the distal opening of the long tube in fluid communication with the long tube is directed towards the opening of the body lumen or in its vicinity. Alternatively, or in addition, the long tube may include or be coupled to a wire that can apply tension to the proximal end of the long tube to bend the distal end of the long tube in a predetermined direction to control the position of the distal opening of the long tube when the distal end exits the endoscope.

[0079] Furthermore, technique 100 may include flowing fluid (106) from a fluid source (e.g., fluid source 40 and / or other suitable fluid sources) through the lumen of the elongate tube toward the opening of the body lumen from the distal opening of the elongate tube. The flow of fluid through the lumen of the elongate tube from the fluid source may be initiated by adjusting or actuating a switch controller (e.g., switch actuator 70 or other suitable switch controller) connected to a valve (e.g., valve 68 or other suitable valve) to open the valve and allow pressurized fluid to flow from the accumulator and the fluid source through the lumen of the elongate tube and to the subject. The accumulator can selectively communicate with the lumen of the elongate tube via a flow valve, and the actuation or adjustment of the valve (e.g., in response to the actuation of the switch controller) can automatically flow fluid from the accumulator out of the lumen of the elongate tube.

[0080] When the valve is in the open state, the pressurized fluid from the fluid source and the accumulator may flow to or toward the opening of the body lumen at an initial first predetermined flow rate and then at a second predetermined flow rate that is non-zero. The flow rate of the fluid to or toward the opening of the body lumen may automatically attenuate from the first predetermined flow rate to the second predetermined flow rate. Although not essential, one or more of the configurations of system 24 described herein may be utilized to supply fluid to the opening of the body lumen at an initial predetermined fluid flow rate that automatically attenuates to the second predetermined flow rate with linear attenuation.

[0081] Furthermore, after all or at least a portion of the fluid has been discharged from the accumulator, adjusting the switch controller to close the valve may prevent fluid from the fluid source and the accumulator from reaching or otherwise flowing to the attached device. Thus, by closing the valve, fluid from the fluid source can be accumulated within the fluid accumulator, which "refills" the system so that fluid can be supplied at the first predetermined flow rate on subsequent occasions.

[0082] The first predetermined flow rate or pressure of the fluid supplied to the opening of the body lumen may provide a force acting on the opening of the body lumen that is sufficient to adjust the opening of the body lumen to an open state. The second predetermined flow rate or pressure of the fluid supplied to the opening of the body lumen may provide a force acting on the opening and the body lumen that is sufficient to maintain the opening of the lumen in an open state during the procedure. Since the surface area on which the fluid acts when maintaining the opening and the body lumen in an open state is larger than the surface area on which the fluid acts when the fluid is being used to adjust the opening of the body lumen to an open state, a lower pressure or flow rate of fluid than that used to open the opening can be used to maintain the opening of the lumen in an open state. Thus, by using a low flow rate, withdrawal rate, or dwell point pressure to maintain the opening of the body lumen in an open state, less fluid may be injected into the subject during the procedure than if the same flow rate required to open the opening of the body lumen were used throughout the procedure, which reduces injury to the subject.

[0083] The steps described above may provide a method for accessing a body lumen, although variations of these methods are also envisioned to achieve the same or similar goals. Figures 8 - 10 show the fluid 46 acting on the opening 48 of the major papilla 16 in the sphincter of Oddi complex of a subject (defining a lumen leading to, for example, the common bile duct 17 and pancreatic duct 19) to adjust the opening 48 from a closed state to an open state and to maintain the opening 48 in an open state. The fluid 46 can be supplied to the subject from a system such as the system 24 described herein and / or from other suitable systems configured to reduce the fluid flow rate from an initial fluid flow rate to a second fluid flow rate during and / or after adjusting the opening of the body lumen to an open state and to use the reduced second fluid flow rate to maintain the opening in an open state. Assuming that a force approximately the same or similar to the force required to open the opening 48 is required to maintain the opening 48 in an open state, since the force is equal to the pressure multiplied by the surface area in contact with the pressure, the opening 48 can be maintained in an open state using a fluid 46 at a lower pressure than the force required to open the opening 48.

[0084] As shown in FIG. 8, a medical device 22 (e.g., an endoscope, a duodenoscope, etc.) is disposed in the target duodenum with its opening 75 facing the opening 48 of the major papilla 16, and the opening 48 is in a closed state. The distal tip of the elongate tube 26 of the system 24 may be directed to exit from the opening 75 of the medical device 22, and the fluid 46 may be output toward the opening 48 at a first predetermined velocity. The fluid 46 may contact the surface area of the closed opening 48 and must have sufficient pressure to overcome the natural force of the sphincter of Oddi complex 20 in order to adjust the opening 48 from the closed state to the open state. In some cases, the initial flow rate or exit velocity of the fluid 46 (which results in the stagnation point pressure on the tissue surface) may be set based on the expected size of the first surface area, but this is not necessary to generate a desired force on the surface area of the closed opening 48 to open the opening 48 while reducing the volume used to open the opening 48.

[0085] The first surface area may depend on the shape of the major papilla 16 in the closed position and the configuration of the fluid 46 that exits the accessory device 14 and contacts the major papilla 16, as shown in FIG. 8. However, for purposes of schematically showing the first surface area in one example, it may be assumed that the first surface area can be approximated by a circle having a diameter SA1, as shown in FIG. 8. When the diameter of the circle is SA1, the circle has an area of approximately 3.14×(1 / 2×D SA1 ) squared times π. SA1 ) 2 which can define the surface area.

[0086] FIG. 9 shows the opening 48 in the open state. At this point, the fluid 46 can enter the body lumen 50, and the flow rate of the fluid 46 may begin to decay from the first predetermined flow rate to a second predetermined flow rate that is slower than the first flow rate and sufficient to maintain the opening 48 of the body lumen 50 in the open state.

[0087] Figure 10 shows the opening 48 that maintains the open state. As shown in Figure 10, the fluid 46 acts on the opening 48 along the length SA2 and the surface area (e.g., the second surface area) of the body lumen 50, and may maintain the opening 48 in the open state during the treatment of the subject. Comparing the first surface area on which the fluid 46 acts as shown in Figure 8 with the second surface area on which the fluid 46 acts as shown in Figure 10, it can be seen that the second surface area (e.g., when the opening 48 is in the open state) is larger than the first surface area (e.g., when the opening 48 is in the closed state). Therefore, the flow rate or fluid pressure in the opening 48 that can be used to maintain the opening 48 in the open state is lower than the flow rate or fluid pressure in the opening 48 required to adjust the opening 48 to the open state.

[0088] The second surface area may depend on the shape of the opening 48 along the length SA2 and the body lumen 50, and the configuration of the fluid 46 that exits the accessory device 14 and contacts the main papilla 16, as shown in Figure 10. However, in one example, to schematically show the second surface area, the second surface area can be approximated by a cylinder without a bottom surface and without an upper surface having a length or height of the distance of SA2, D SA2 As a result, it can be assumed that the second surface area can be approximately (D SA2 ) × the circumference of the opening 48.

[0089] Examples of fluid flow during treatment In one exemplary configuration of the system 24, carbon dioxide gas (CO2) may be delivered to the distal end of the sphincterotomy catheter to access and dilate the major duodenal papilla (papilla of Vater). In this example, the CO2 lumen of the catheter may have an outlet diameter of 0.016 inches (406 μm), and the gas delivery system may be designed to deliver fluid from the catheter at a first predetermined flow rate and exit velocity when the gas flow is first triggered, and then linearly decay to a second predetermined flow rate and exit velocity.

[0090] When the flow rate for CO2 delivery is set at 1.0 liter per minute (lpm) (e.g., 16.67 milliliters per second) in the fluid source, as a result, the exit velocity of the gas exiting the sphincterotomy knife and entering the subject is 128.5 meters per second (m / s), which is sufficient to adjust the major duodenal papilla to an open state. When the flow rate for CO2 delivery is set at 0.5 lpm, the exit velocity of the gas exiting the sphincterotomy knife and entering the subject is 64.25 m / s, which is sufficient to maintain the opening of the major duodenal papilla in an open state.

[0091] In some procedures, for the purpose of adjusting and maintaining the papilla in an open state during the procedure, gas is supplied to the major duodenal papilla for 45 seconds. If gas is supplied to the papilla for the entire 45 - second gas delivery at the rate required to initially open the papilla (e.g., 1.0 liter per minute in this example), 750.15 milliliters of fluid can be delivered to the subject. When a gas with a first predetermined flow rate of 1.0 lpm, a second predetermined flow rate of 0.5 lpm, and a decay rate from the first predetermined flow rate to the second predetermined flow rate of 0.52 ml / s is supplied to the subject via a system configured to reduce the pressure or flow rate of the fluid supplied to the subject by the method described herein or other methods, the volume of fluid delivered to the subject over 45 seconds of fluid supply to the subject is 441.73 milliliters.

[0092] The volume of fluid supplied to the subject over 45 seconds using the adjusted attenuation flow system that utilizes the parameters of this embodiment is approximately 58.89% of the volume supplied by a system that does not reduce the flow rate after the nipple is opened. Additionally, in the reduction system that uses an attenuation rate of 0.52 ml / s, the flow rate is reduced from a first predetermined flow rate (1.0 lpm) for 16 seconds and maintained at a second predetermined steady-state flow rate (0.5 lpm) that is not zero for 29 seconds (e.g., longer than the time the fluid is supplied at the first predetermined flow rate), which reduces the force acting on the body tissue in contact with the fluid flow (e.g., reduces trauma) compared to a constant flow system that supplies fluid at a constant rate set to a speed necessary to generate sufficient force to open the opening of the nipple.

[0093] It should be understood that the present disclosure is merely exemplary in many aspects. Without departing from the scope of the present disclosure, changes can be made in detail, particularly with regard to the shape, size, and arrangement of the steps. This may include the use of any of the features of one exemplary embodiment used in other embodiments within an appropriate scope. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.

Claims

1. A medical device for accessing a target body lumen, comprising: a fluid accumulator having a proximal end and a second end configured to receive fluid from a pressurized gas source; a flexible elongate tube having a distal end configured to be directed toward the proximal end and an opening of the body lumen; a lumen extending from the distal end of the flexible elongate tube toward the proximal end of the flexible elongate tube, the lumen being selectively communicable with the second end of the fluid accumulator; a switch configured to adjust communication between the fluid accumulator and the lumen upon actuation of the switch; A medical device comprising the above components.

2. The medical device according to claim 1, wherein upon actuation of the switch, fluid is automatically withdrawn from the distal end of the lumen at a first rate for a first time and at a second rate for a second time after the first time, and the first rate is faster than the second rate.

3. The medical device according to claim 1, wherein the switch is connected to a valve configured to selectively block fluid flow downstream of the fluid accumulator and upstream of the distal end of the lumen.

4. The medical device according to claim 1, wherein upon a first actuation of the switch, the fluid accumulator and the lumen are configured to be in communication, and upon a second actuation of the switch, fluid flow between the fluid accumulator and the lumen is configured to be blocked.

5. The medical device according to claim 1, wherein the fluid accumulator is a coil of tubing.

6. A first tube portion extending between the fluid accumulator and the switch; and a second tube portion extending between the switch and a third tube portion, the third tube portion including the flexible elongate tube. The medical device according to claim 1, further comprising the above components.

7. a fluid source lumen extending from the fluid accumulator and configured to communicate with a fluid source; and a flow restrictor disposed along the fluid source lumen. The medical device according to claim 1, further comprising the above components.

8. A system comprising a fluid accumulator and a sphincterotome in communication with the fluid accumulator. The system comprising the above components. The fluid accumulator is upstream of the sphincterotomy knife and is configured to accumulate pressurized fluid for selectively discharging at an initial first velocity through the distal end of the sphincterotomy knife, the first velocity decaying over time to a second velocity, system.

9. The system of claim 8, further comprising a pressurized fluid source upstream of the fluid accumulator and in communication with the fluid accumulator for supplying pressurized fluid to the fluid accumulator.

10. The system of claim 8, further comprising a valve upstream of the sphincterotomy knife and downstream of the fluid accumulator, the valve being configured to regulate the flow of fluid from the fluid accumulator to the sphincterotomy knife.

11. A method of accessing a target body lumen, comprising: extending a long tube having a distal end and a lumen through a working channel of an endoscope extending into the target; orienting the distal end of the long tube toward an opening of the body lumen; flowing fluid from a fluid source through the lumen and out of the distal end of the long tube toward the opening of the body lumen; including Flowing fluid out of the distal end of the long tube via the lumen from the fluid source includes initially outputting the fluid from the distal end of the long tube at a first predetermined velocity, the first predetermined velocity automatically decaying over time to a second predetermined velocity that is non-zero, method.

12. The method of claim 11, wherein the first predetermined velocity is set to transition the opening of the body lumen from a closed state to an open state.

13. The method of claim 11, wherein the non-zero second predetermined velocity is set such that the opening remains open once it is opened.

14. The method of claim 11, wherein the non-zero second predetermined velocity is maintained for a longer period than the period during which the fluid is output at the first predetermined velocity.

15. opening a valve to allow fluid to flow out of the distal end of the long tube via the lumen from the fluid source; closing the valve to accumulate fluid from the fluid source within a fluid accumulator that selectively communicates with the lumen; The method of claim 11, further comprising.

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