Method and system for perfusing a closed subcutaneous cavity

Abstract

Systems and methods for preventing, treating, or managing the risk of infection in a closed subcutaneous cavity. In one example, the method comprises (a) implanting an elongated fluid conduit such that the fluid conduit communicates with a closed subcutaneous cavity, and (b) operating a perfusion system according to a perfusion treatment program, the operation of which comprises (i) delivering perfusion fluid from a perfusion fluid source through the fluid conduit to the closed subcutaneous cavity according to parameters of the perfusion treatment program, (ii) enabling the retention of the perfusion fluid in the closed subcutaneous cavity according to another parameter, and (iii) delivering the perfusion fluid from the closed subcutaneous cavity through the fluid conduit according to another parameter.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of the priority and filing date of U.S. Provisional Patent Application No. 63 / 503,591, filed May 22, 2023, for "Closed Subcutaneous Cavity Irrigation Methods And Systems", the entire content of which is incorporated herein by reference.

[0002] Perfusion methods and systems, particularly perfusion methods and systems for performing perfusion of a closed subcutaneous cavity for the prevention, treatment, or management of the risk of infection. Perfusion includes, but is not limited to, cleansing (lavage) such as washing by flushing with a fluid.

Background Art

[0003] Joint infections are common, costly, and serious illnesses that often require multiple surgeries, long - term antibiotics, and long hospital stays, and may even require amputation. Treatment often involves surgical procedures for perfusion and debridement of the infected tissue. In the case of an infected artificial joint, when the infection has resolved, it may be necessary to remove and re - implant the implant. Delays in diagnosis leading up to treatment exacerbate the problem. Clinicians can perform joint aspiration in the clinic and initiate oral antibiotics early, but there is no standardized method / device for repeated aspiration and perfusion of the joint.

[0004] Other types of deep infections present similar challenges. Deep infections can form abscess cavities that are difficult to treat with intravenous antibiotics alone. Deep infections often require multiple incisions and large-volume drainage of the infected area. Because multiple surgical procedures increase the risk of complications and prolong hospital stays, intervening radiologists are often asked to percutaneously place indwelling catheters into hard-to-reach abscess cavities to drain the infection, hoping to eliminate the need for major surgery. Percutaneous catheter placement currently does not include a method for drainage, and drainage alone can prolong the course of the infection. [Overview of the Initiative]

[0005] The inventors of this invention have invented an improved system and method for preventing, treating, or managing the risk of infection in closed subcutaneous cavities.

[0006] In one example, a method for preventing, treating, or addressing the risk of infection in a closed subcutaneous cavity using a perfusion system includes implanting an elongated fluid conduit in communication with the closed subcutaneous cavity. The perfusion system is then operated according to a perfusion treatment program that includes at least one parameter for delivering perfusion fluid to the closed subcutaneous cavity, at least one parameter for the residence time of the perfusion fluid in the closed subcutaneous cavity, and at least one parameter for delivering perfusion fluid from the closed subcutaneous cavity. Operating a perfusion system according to a perfusion processing program includes (i) delivering the perfusion fluid from a perfusion fluid source through a fluid conduit to a closed subcutaneous cavity according to parameters for delivering the perfusion fluid to a closed subcutaneous cavity, (ii) enabling the perfusion fluid to reside in the closed subcutaneous cavity according to parameters for residence time, and (iii) delivering the perfusion fluid from the closed subcutaneous cavity through a fluid conduit according to parameters for delivering the perfusion fluid from the closed subcutaneous cavity.

[0007] In this example, the perfusion system may include a configurable pump and valve configuration. When delivering perfusion fluid from a perfusion fluid source to a closed subcutaneous cavity, the perfusion system can be configured to a first state in which fluid flow is allowed between the perfusion fluid source and the pump, and fluid flow is prevented between the pump and the perfusion fluid outlet. When delivering perfusion fluid from the closed subcutaneous cavity to the perfusion fluid outlet, the perfusion system can be configured to a second state in which fluid flow is prevented between the perfusion fluid source and the pump, and fluid flow is allowed between the pump and the perfusion fluid outlet.

[0008] In this example, the elongated fluid conduit may be a multi-lumen catheter. One lumen can be configured to deliver perfusion fluid (and optionally a drug) to and from a closed subcutaneous cavity. Additional lumen can be configured to deliver ultrasound and antibiotic light to the closed subcutaneous cavity. [Brief explanation of the drawing]

[0009] [Figure 1] This shows an example of a permeable flow system. [Figure 2] This shows an example of a multi-tubular catheter. [Figure 3] This shows an example of a wearable permeable flow system. [Figure 4] An example of a permeation method is shown. [Figure 5] This shows an example of a permeation system that includes a passive drainage function. [Figure 6] The configuration and results of the cross-contamination test are shown. [Figure 7] The configuration and results of the cross-contamination test are shown. [Figure 8] The configuration and results of the cross-contamination test are shown. [Figure 9] The configuration and results of the cross-contamination test are shown. [Modes for carrying out the invention]

[0010] Figure 1 shows an example of a perfusion system for preventing, treating, or managing the risk of infection in a closed subcutaneous cavity 100. In some applications, the closed subcutaneous cavity 100 may be a joint capsule, seroma, abscess, surgical defect, or subcutaneous wound. The perfusion system is for non-surgical cleaning, flushing, and other perfusion of the closed subcutaneous cavity 100.

[0011] In the example shown in Figure 1, the perfusion system includes an elongated fluid conduit 202 configured to be implanted in a closed subcutaneous cavity 100, a pump 204 configured to deliver perfusion fluid through the elongated fluid conduit 202, a perfusion fluid source 206 for supplying perfusion fluid to the pump 204, a fluid outlet container 208 for receiving used perfusion fluid delivered from the closed subcutaneous cavity 100, and a drug source 210 for supplying a drug to the pump 204. In some cases, the drug may be an antibiotic or an antibiofilm agent. Examples of antibiofilm agents include natural antibiofilm agents such as phytochemicals, biosurfactants, antimicrobial peptides, and microbial enzymes.

[0012] In the example in Figure 1, the system uses only a single pump 204 configured to deliver several different fluids to and / or remove them from a closed subcutaneous cavity 100, avoiding the need for multiple pumps, which can increase the size, weight, and complexity of the system (particularly problematic when used in wearable systems, as described below in the context of Figure 3). In the example in Figure 1, the pump 204 is a reversible pump (e.g., a reversible peristaltic pump or other bidirectional pump) communicating with an elongated fluid conduit 202, a perfusion fluid source 206, a drug source 210, and a fluid outlet container 208.

[0013] In the example in Figure 1, several valves are used with the pump 204 depending on the operating state of the system. Valve 234 regulates the flow of fluid from the perfusion fluid source 206 to the pump 204. Valve 236 regulates the flow of drug from the drug source 210 to the pump 204. Valve 238 regulates the flow of fluid from the pump 204 to the fluid outlet container 208. The system is configured to open and close valves 234, 236, and 238 depending on the operating state of the system. For example, when the system is in a state to deliver perfusion fluid and drug to a closed subcutaneous cavity 100, the system operates by opening valves 234 and 236 and closing valve 238, causing the pump 204 to operate in a direction that delivers fluid from the perfusion fluid source 206 and drug source 210 through the pump 204 and through the elongated fluid conduit 202 to the closed subcutaneous cavity 100. When the system is supplying only perfusion fluid to the closed subcutaneous cavity 100 and not supplying the drug, the system operates by opening valve 234 and closing valves 236 and 238. In applications where it may be desirable to vary the amount of drug supplied to the closed subcutaneous cavity 100, mixing valves or other variable-state valves can be used instead of valves that are either fully open or fully closed. In some cases, one or more switching valves may be used at the intersection of three or more fluid channels.

[0014] The system in Figure 1 further includes an energy source 218 and an antimicrobial light source 220. The energy source 218 is configured to generate mechanical, electrical, or ultrasonic energy to be delivered to the closed subcutaneous cavity 100 in order to improve the fluid flow within the closed subcutaneous cavity 100. In one exemplary embodiment, the energy source 218 may be an ultrasonic transducer. In some cases, the ultrasonic transducer can operate at frequencies in the range of 10 kHz to 1000 kHz, or in the range of 10 kHz to 100 kHz, or in the range of 10 kHz to 50 kHz. Delivering ultrasonic energy to the closed subcutaneous cavity may act to suspend infectious agents in the perfusion fluid so that infectious agents can be more easily removed from the closed subcutaneous cavity 100. In one exemplary embodiment, the antimicrobial light source 220 is configured to generate light (e.g., blue light having one or more frequencies in the range of 350 nm to 450 nm) to be delivered to the closed subcutaneous cavity 100 in order to provide an antimicrobial effect. In another embodiment, the system does not include one or both of the energy sources 218 of the antimicrobial light source 220.

[0015] The system in Figure 1 further includes a controller 212. The controller is configured to operate the perforation system according to a perforation program. In the example in Figure 1, the controller 212 includes an input unit 214 and a display 216 for the user to select a perforation program. In some embodiments, the user can select from several pre-programmed perforation programs stored in the memory device of the controller 212. In some embodiments, the user can input a custom perforation program into the controller 212. The selected perforation parameters may include several parameters that specify the particular perforation regime to be used.

[0016] The perfusion program may include (i) at least one parameter for delivering perfusion fluid from a perfusion fluid source 206 to a closed subcutaneous cavity 100, (ii) at least one parameter relating to the residence time of the perfusion fluid in the closed subcutaneous cavity 100, and (iii) at least one parameter for delivering perfusion fluid from the closed subcutaneous cavity 100 to a fluid outlet container 208.

[0017] Parameters for delivering perfusion fluid from the perfusion fluid source to a closed subcutaneous cavity may include, but are not limited to, the pump direction, pump operation duration, pump speed, and valve state. Parameters for the residence time of the perfusion fluid in the closed subcutaneous cavity may include, but are not limited to, the residence time duration and valve state. Parameters for delivering perfusion fluid from the closed subcutaneous cavity to the fluid outlet container may include, but are not limited to, the pump direction, pump operation duration, pump speed, and valve state.

[0018] The controller 212 can be configured to pump the perfusion fluid from the perfusion fluid source 206 through the elongated fluid conduit 202 to the closed subcutaneous cavity 100, according to parameters for supplying the perfusion fluid to the closed subcutaneous cavity 100. The controller 212 can be further configured to allow the perfusion fluid to remain in the closed subcutaneous cavity 100, according to parameters for residence time. The controller 212 can be further configured to pump the perfusion fluid from the closed subcutaneous cavity 100 to the fluid outlet container 208, according to parameters for supplying the perfusion fluid from the closed subcutaneous cavity.

[0019] The perfusion program can include additional parameters for adjusting the operation of the system. Examples of additional parameters include: (i) one or more parameters specifying the total number of cycles or total time of the perfusion process program, (ii) one or more parameters for delivering a drug into a closed subcutaneous cavity, (iii) one or more parameters governing the operation of the energy source 218, and (iv) one or more parameters governing the operation of the antimicrobial light source 220.

[0020] FIG. 2 shows the elongated fluid conduit 202 from FIG. 1 in more detail. In this example, the elongated fluid conduit 202 is a multi-lumen catheter. The elongated fluid conduit 202 includes a main lumen 222. The system is configured to send perfusion fluid from the perfusion fluid source 206 and a drug from the drug source 210 through the main lumen 222. Further, the system is configured to send perfusion fluid (and other fluids) from the closed subcutaneous cavity 100 through the main lumen 222 to the fluid outlet container 208.

[0021] The secondary lumen 224 provides a passage for an energy transmission member 226 configured to deliver energy from the energy source 218 to the closed subcutaneous cavity 100. Another secondary lumen 228 provides a passage for a light transmission member 230 (e.g., an optical fiber) configured to deliver antimicrobial light from the light source 220 to the closed subcutaneous cavity 100.

[0022] In the example of FIG. 2, the elongated fluid conduit 202 includes a pressure sensor 232 for measuring the pressure within the closed subcutaneous cavity 100. Further, the system can include one or more flow meters or other devices for measuring the amount of fluid delivered into the cavity 100 and the amount of fluid delivered out of the cavity 100.

[0023] In some embodiments, the system may be configured to quantify the amount of perfusion fluid being supplied to and from a closed subcutaneous cavity 100, and / or to measure the pressure inside the closed subcutaneous cavity 100. This information may be used by the system's safety functions. For example, if the amount of perfusion fluid in the closed subcutaneous cavity and / or the pressure measurement inside the closed subcutaneous cavity exceeds a threshold, a safety warning can be triggered, which can automatically stop the supply of fluid to the cavity and / or open an output valve to allow the fluid to be withdrawn from the cavity. As another example, data on the amount of fluid entering and leaving the cavity and / or the pressure measurement inside the cavity can be used in a feedback loop to adjust subsequent cycles of fluid entering and leaving the cavity. For example, the system may be configured to adjust the amount of perfusion fluid entering and leaving the cavity 100 so that a target pressure value or target pressure range is maintained as the perfusion fluid circulates through the cavity 100.

[0024] Figure 3 shows an example of a wearable perfusion system. In this example, the system includes a wearable unit 240 and a remote controller 242 that communicates wirelessly with the wearable unit 240. In other embodiments, the controller 242 may communicate with the wearable unit 240 via a wired connection. Similar to the example shown in Figure 1, the wearable unit 240 may include a controller, a pump, a perfusion fluid supply source, a drug supply source, a fluid outlet container, an energy source (e.g., an ultrasonic transducer), and an antimicrobial light source. The wearable unit 240 can be configured to facilitate the periodic replacement of the perfusion fluid supply source and drug supply source when depleted, and the fluid outlet container when full. In some embodiments, the perfusion fluid supply source and fluid outlet container may have a capacity of 1050 mL or less. Furthermore, the wearable unit may include a rechargeable battery or other power source and a strap 244 or other components for securing the wearable unit to the patient. In some embodiments, the wearable unit may be configured to be worn around the waist (e.g., as a "fanny pack"), as a backpack, as a wallet or sling, or attached to a wallet or sling, or as a rolling suitcase or attached to a rolling suitcase.

[0025] Figure 4 illustrates exemplary methods for preventing, treating, or managing the risk of infection in a closed subcutaneous cavity using a perfusion system (such as the perfusion systems shown in Figures 1-3).

[0026] In step 302 of Figure 4, the elongated fluid conduit is implanted in the closed subcutaneous cavity so that the fluid conduit communicates with the closed subcutaneous cavity. The implantation of the elongated fluid conduit can be performed in a manner similar to that of implanting a typical catheter or surgical drain.

[0027] In step 304, a perfusion treatment program is selected. In some embodiments, the operator can select from several pre-programmed perfusion treatment programs stored in the perfusion system, or a custom perfusion treatment program can be entered into the system.

[0028] The selection of a perfusion treatment program can determine (or at least initially determine) several parameters related to the perfusion treatment. These parameters may include, for example, (i) at least one parameter for delivering the perfusion fluid into a closed subcutaneous cavity, (ii) at least one parameter for the residence time of the perfusion fluid in the closed subcutaneous cavity, (iii) at least one parameter for delivering the perfusion fluid from the closed subcutaneous cavity, (iv) at least one parameter specifying the total number of cycles or total time of the perfusion treatment program, (v) at least one parameter for delivering the drug to the closed subcutaneous cavity, (vi) at least one parameter for delivering mechanical, electrical, or ultrasonic energy to improve the fluid flow within the closed subcutaneous cavity, and (vii) at least one parameter for delivering antimicrobial light to the closed subcutaneous cavity.

[0029] In step 306, the perfusion system operates according to the selected perfusion treatment program. In this particular example, the operation of the perfusion system includes multiple cycles of substep 306a and the subsequent substeps 306b, 306c, and 306d.

[0030] In substep 306a, the resident fluid in the closed subcutaneous cavity is drawn out of the closed subcutaneous cavity. When the method of Figure 4 is performed using the system of Figure 1, in substep 306a, the system closes valves 234 and 236, opens valve 238, and operates pump 204 in a direction that draws the resident fluid from the closed subcutaneous cavity through the main lumen 222 of the elongated fluid conduit 202 to the fluid outlet container 208. In substep 306a, the system can optionally capture or monitor data regarding the amount of resident fluid removed and the pressure or pressure change in the closed subcutaneous cavity 100, and optionally adjust the operating parameters of the selected permeation treatment program according to that data.

[0031] In substep 306b, the system delivers the perfusion fluid into the closed subcutaneous cavity according to parameters for delivering the perfusion fluid into the closed subcutaneous cavity. When the method of Figure 4 is performed using the system of Figure 1, in substep 306b, the system opens valve 234, closes valve 238, and operates pump 204 in the direction (opposite to the pump direction in substep 306a) that delivers the perfusion fluid from the perfusion fluid source 206 through the main lumen 222 of the elongated fluid conduit 202 to the closed subcutaneous cavity 100. Furthermore, depending on the parameters of the selected perfusion treatment program, the system may open valve 234 so that the drug is delivered simultaneously with the perfusion fluid from the drug source 210 through the main lumen 222 of the elongated fluid conduit 202 to the closed subcutaneous cavity 100. In other embodiments, the system may deliver the drug to the closed subcutaneous cavity in a step separate from the delivery of the perfusion fluid. In substep 306b, the system can optionally capture or monitor data regarding the amount of perfusion fluid delivered to the closed subcutaneous cavity 100 and the pressure or pressure changes within the closed subcutaneous cavity 100, and optionally adjust the operating parameters of the selected perfusion treatment program according to that data. For example, in one embodiment, the system may be configured to reduce the amount of perfusion fluid delivered to the closed subcutaneous cavity when the pressure within the cavity exceeds a certain threshold.

[0032] In some embodiments, in substep 306b, the perfusion fluid is introduced into a closed subcutaneous cavity at a flow rate of less than 20 mL / second or less than 10 mL / second and an outlet pressure of less than 200 pounds / square inch or less than 100 pounds / square inch.

[0033] In substep 306c, the perfusion fluid can reside in a closed subcutaneous cavity according to a parameter relating to residence time. In substep 306c, the system can optionally capture or monitor data relating to pressure or pressure changes within the closed subcutaneous cavity 100, and optionally adjust the operating parameters of the selected perfusion treatment program according to that data.

[0034] In substep 306d, the system discharges the perfusion fluid from the closed subcutaneous cavity according to parameters for delivering the perfusion fluid into the closed subcutaneous cavity. When the method of Figure 4 is performed using the system of Figure 1, in substep 306d, the system closes valves 234 and 236, opens valve 238, and operates pump 204 in the direction (opposite to the pump direction in substep 306b) to deliver the perfusion fluid from the closed subcutaneous cavity 100 through the main lumen 222 of the elongated fluid conduit 202 to the fluid outlet container 208. In substep 306d, the system can optionally capture or monitor data regarding the amount of perfusion fluid removed and the pressure or pressure change within the closed subcutaneous cavity 100, and optionally adjust the operating parameters of the selected perfusion processing program according to that data.

[0035] After substep 306d, the system may perform additional cycles of substeps 306b, 306c, and 306d according to selected parameters relating to the total cycles or total time of the perfusion treatment program. In some applications, the total time may exceed 8 hours, or even 24 hours.

[0036] During any of the aforementioned steps, or in a separate step between one of the aforementioned steps, the system can deliver antimicrobial light, and / or mechanical, electrical, or ultrasonic energy, to the closed subcutaneous cavity.

[0037] Figure 5 shows another example of a perfusion system for preventing, treating, or managing the risk of infection in a closed subcutaneous cavity 100. In the example in Figure 1, all flow of perfusion fluid into and out of the closed subcutaneous cavity 100 passes through pump 204. In that example, when pump 204 is not operating, the perfusion fluid and other fluids in the cavity 100 cannot drain out of the closed subcutaneous cavity 100 through the elongated fluid conduit 202. Figure 5 shows an alternative configuration that allows passive drainage as part of a predetermined treatment plan.

[0038] In the example shown in Figure 5, the passive drain outlet 240 communicates with the elongated fluid conduit 202 between its distal end (the part implanted in the closed subcutaneous cavity 100) and the pump 204. The passive drain valve 242 communicates with the passive drain outlet 240, and the controller 212 is configured to open the passive drain valve 242 when the system is in a passive drain state. Furthermore, the controller 212 can be configured to close the passive drain valve 242 when the pump 204 delivers perfusion fluid to and from the closed subcutaneous cavity 100. Parameters for programming the passive drain state (e.g., a preset time or other criterion for entering the passive drain state, the duration of the passive drain state, etc.) may be included in the controller 212.

[0039] When the system is in a passive draining state, the fluid can be discharged from the closed subcutaneous cavity 100 to the passive drain outlet 240. The passive drain outlet 240 can be truly "passive" in the sense that only gravity is required to discharge the fluid from the closed subcutaneous cavity 100 to the passive drain outlet 240. In other embodiments, the passive drain outlet 240 may be a valve canister or other device that can create a negative pressure environment to facilitate discharge from the closed subcutaneous cavity 100 without the operation of the pump 204. Exemplary Use Cases

[0040] The system and method described above can be deployed and implemented in a variety of clinical settings, such as clinics, interventional radiology departments, or operating rooms, as a wearable home-use product to treat various types of joint infections. Examples of target patient populations include those with swelling around prosthetic joints, infected congenital joints, and infected seromas. Furthermore, the system and method can be used to treat severely ill patients who are not candidates for formal surgical flushing. In addition, the system and method can be used as a prophylactic postoperative treatment. The system and method are expected to improve the effectiveness of initial flushing and antibiotic treatment, reduce costly hospitalizations, and open up new opportunities for out-of-operating use.

[0041] Promising example 1: A patient presents to the emergency department with knee effusion. Previous knee replacement had been performed at another hospital outside the state. After consultation with orthopedics, knee aspiration is performed. Fluid is drained, and the patient is admitted for intravenous antibiotics. Microbiological analysis confirms infection. The patient is transferred to the operating room within 1-2 days for perfusion, debridement, and component replacement. A surgical drain is placed, and intravenous antibiotics are maintained for the patient for 6 weeks. Persistent cloudy drainage was observed. No additional flushing was performed. In this promising case, the systems and methods described above can be used postoperatively to provide additional flushing and deliver antibiotics directly to the site of infection, improving the effectiveness of initial treatment.

[0042] Promising example 2: A patient presents to the emergency department with knee effusion. A significant surgical history involving knee replacement was complicated by an infection requiring surgical lavage. Consultation with orthopedics is requested, and the knee joint is aspirationed again. Fluid is drained, and the patient is admitted for intravenous antibiotics. Microbiological analysis confirms reinfection. Three days later, the patient is transferred to the operating room for perfusion, debridement, removal of metal implants, and placement of an antibiotic-impregnated cement spacer. A surgical drain is placed for three days, and intravenous antibiotics are maintained for six weeks. The patient is returned to the operating room two months later for spacer removal and joint revision. Intraoperative evaluation by Gram staining reveals persistent infection. A second cement spacer is placed, and intravenous antibiotics are administered for another two months. The patient is returned to the operating room for a third time for removal of the cement spacer and joint revision. In this promising example, the aforementioned system and method could have been placed postoperatively to provide additional rinsing and deliver antibiotics directly to the site of infection, thereby improving the effectiveness of the initial treatment.

[0043] Promising example 3 A patient presents to the clinic with knee effusion. The knee is aspirated, and cloudy fluid is observed. The patient receives a prescription for antibiotics and is instructed to return if symptoms worsen before being sent home. The effusion worsens, and the patient returns to the ED the following day with increased pain. The patient is admitted to the hospital, and intravenous administration of antibiotics is initiated. The knee is aspirationed again, and the fluid is sent again for culture. The first set of culture results were positive for infection. The patient is transferred to the operating room for arthroscopic flushing and drain placement. In this promising case, a wearable embodiment of the system and method described above could have been fitted after aspiration was performed during the initial clinic visit. This would have provided a continuous cycle of perfusion and aspiration while waiting for the cultures. Once the culture results were available, antibiotic infusion could have been adjusted based on culture specificity.

[0044] Promising example 4 A woman with breast cancer was involved in a car accident and sustained large open wounds on the outer side of her right thigh and knee. Surgical debridement and wound suturing were performed at another hospital. One week prior to her visit to our facility, she had a follow-up with a surgeon at the other hospital, during which she expressed concerns about infection due to swelling and discharge along her thigh. The surgeon did not address these concerns. The patient visited our facility after the swelling and discharge increased. Imaging confirmed fluid accumulation due to a difference between seroma and abscess. The fluid was aspirated, and microbiological testing was positive for MRSA. A second surgical debridement and placement of a surgical drain were required. Cloudy drainage persisted for several days postoperatively. As a result, she had multiple and prolonged hospital stays. The patient may require additional surgical irrigation. In this promising case, the system and methods described above could have been applied to continuous perfusion and antibiotic delivery as soon as swelling was observed in the area. This would likely have resolved the infection without requiring additional surgical intervention. Furthermore, the aforementioned wearable systems and methods could have reduced the costly hospitalization of inpatients.

[0045] Promising example 5 Severely ill patients may have abscesses or joint infections that lead to sepsis, but these patients may be too unstable to undergo formal surgical irrigation. Continuous suction is often performed bedside, with or without IR drain placement. These stopgap measures have limited effectiveness. In this promising case, the system and method described above could be an ideal solution for this patient population to provide continuous perfusion and antibiotic delivery bedside.

[0046] Promising example 6 Prophylactic use of vancomycin powder placed on spinal wounds has been shown to reduce the incidence of infection. However, the use of vancomycin powder increases the incidence of postoperative seroma. The proposed mechanism is that vancomycin powder crystallizes as a salt with hydrochloride, which creates an osmotic gradient when placed on the surgical wound. Persistent seroma can lead to patient discomfort and an increased risk of late-stage infection. In this promising case, the system and method described above can be used in high-risk surgical wounds to prevent postoperative infection and seroma formation.

[0047] Notes on further promising applications The system described above can be used with standard surgical drains or specialized catheters, can be placed beside the patient's bed, in a clinic, interventional radiology department, or operating room, can be used on numerous anatomical sites (knee, shoulder, hip, thigh, calf, pelvis, paravertebral column), can reduce the length of hospital stay and the need for multiple surgical procedures, can include a variety of treatments such as blue light and ultrasound treatment, can include machine learning algorithms to personalize the treatment regimen according to the patient's volume and pressure sensitivity, may be programmable, and can adjust antibiotic treatment according to future culture results.

[0048] Assessment of the risk of cross-contamination The inventors of the present invention evaluated the effectiveness of the above-described system and method in preventing cross-contamination during the push / pull cycle of the system. Figure 6 schematically shows the configuration of the system for this evaluation. For this evaluation, the push / pull cycle includes drawing approximately 50 mL of input liquid from a fluid source 206, delivering it to a closed subcutaneous cavity 100 for approximately 16 seconds, and then recovering the liquid from the closed subcutaneous cavity 100 and placing it in a fluid outlet container 208. A single pump 204 facilitates both input and output functions, with the fluid source valve 234 open and the fluid outlet valve 238 closed during the push phase, and the fluid source valve 234 closed and the fluid outlet valve 238 open during the pull phase.

[0049] The inventors of the present invention wanted to investigate how well a valve system performs in maintaining separation between a fluid source 206 and a fluid outlet 208 in a push / pull cycle using a common pump 204 and a common fluid conduit 202. The inventors of the present invention performed the evaluation by measuring the pH level using a litmus test to determine whether the clean fluid source 206 becomes contaminated after multiple push / pull cycles.

[0050] A protocol was devised that involved measuring the pH in the fluid source 206, the fluid outlet 208, and the closed subcutaneous cavity 100 using litmus paper, and testing it through multiple push / pull cycles. Using a standard pH litmus scale, the pH of the liquid was determined based on the color of the litmus test strip after immersion in the liquid.

[0051] Two tests were conducted: one to establish a baseline free from intentional contamination, and the other to intentionally alter the pH within the joint. These tests helped to understand the fluid behavior within the system and its ability to clean a closed subcutaneous cavity 100 without cross-contamination.

[0052] In each test, the pH of the liquid extracted from the fluid source 206, the fluid outlet 208, and the closed subcutaneous cavity 100 was measured. In this experiment, sterile water with a pH of 7.0 was used as the liquid for the fluid source.

[0053] Litmus tests were performed to establish baseline measurements of the fluids extracted from the fluid source 206, the fluid outlet 208, and the closed subcutaneous cavity 100. A push / pull cycle was then performed, and the pH was measured at each position. This process was repeated twice. The pH in the output container was then visually compared to the original pH observed at the knee. The pH results of the litmus test specimens are shown in Figure 7.

[0054] For intentional contamination testing, betadine was used as a pH modifier due to its pH properties and distinctive color, facilitating observation of the cleaning process within cavity 100. Considering the tissue characteristics, a drug capable of altering the pH by 3 units was required to effectively modify the joint environment. This selection allowed for the assessment of cross-contamination of the system while ensuring an accurate reflection of joint behavior in a clinical setting, minimizing tissue degeneration or damage.

[0055] To initiate the intentional pH change test, 10 mL of a pH-changing agent (Betadine) was injected into the cavity. The pH of the fluid source 206, the fluid outlet 208, and the closed subcutaneous cavity 100 was then measured after a push / pull cycle. The pH of the fluid outlet 208 was then compared to the original pH observed in cavity 100. This process was repeated six times for the intentional pH contamination test.

[0056] In the intentional contamination test, the pH of cavity 100 was re-evaluated after 7 cycles to determine whether the system had effectively cleaned the joint cavity 100. The pH results of the litmus test specimens from this test are shown in Figure 8.

[0057] In the intentional pH change test results (Figure 8), the initial pH of the knee joint cavity was measured at 4.0 (label A). However, by the end of the seventh cycle, the pH had risen to approximately 7.0 (label B), which was consistent with the pH levels of both the source and outlet and consistent with the baseline pH observed before the start of the test.

[0058] Throughout the cycle, the pH of the source liquid remained consistent, showing no decrease, indicating minimal infiltration of betadine into the sterile water supply. This observation was supported by the absence of color change in the IV bags and tubing used for the source in the test. Similarly, the outlet pH remained stable at approximately 7 throughout the 7 cycles. However, a significant color change was observed in the liquid of the outlet container, attributed to the presence of betadine from the joint, indicating that the system's joint irrigation was successful with minimal risk of cross-contamination.

[0059] During testing, minimal backflow was observed during the pull phase of the cycle. However, as shown in Figure 9, fluid from the articular cavity flowed consistently toward the source tube throughout all seven cycles without crossing with the source itself, demonstrating that the valve system effectively prevented such cross-contamination within the system.

[0060] Following pH testing, additional push / pull cycles were performed to determine the optimal number required for thorough cleaning of the joint cavity. By the eighth cycle, the fluid removed from the cavity appeared almost clear, with minimal traces of Betadine. However, it was acknowledged that this result may change in the future, as the decreasing amount of fluid carried through the joint with each cycle suggested that more cycles might be required to completely clean the joint cavity.

[0061] In conclusion, the results demonstrated by pH measurements and visual observation of betadine in the tubes indicate the absence of significant liquid cross-contamination and backflow to the input fluid source, thus demonstrating that little to no cross-contamination occurs during system operation.

[0062] Note Additions, deletions, substitutions, and other modifications may be made to the exemplary systems and methods described above without departing from the scope or spirit of the claimed invention.

Claims

1. A perfusion system for addressing the risk of infection in closed subcutaneous cavities, (a) an elongated fluid conduit configured to be implanted in a closed subcutaneous cavity, (b) A pump configured to deliver perfusion fluid through the elongated fluid conduit to the closed subcutaneous cavity and to deliver fluid from the closed subcutaneous cavity through the elongated fluid conduit, (c) Perfusible fluid supply source and (d) A fluid supply source valve located along the fluid path between the perfusion fluid supply source and the pump, (e) A controller configured to operate the permeation system and Equipped with, A perfusion system in which the controller is configured to open the fluid source valve when the pump delivers the perfusion fluid from the perfusion fluid source through the fluid conduit, and the controller is configured to close the fluid source valve when the pump delivers the perfusion fluid from the closed subcutaneous cavity.

2. (a) The controller is configured to operate the perfusion system according to a perfusion processing program, the perfusion processing program includes (i) at least one parameter for sending the perfusion fluid to the closed subcutaneous cavity, (ii) at least one parameter relating to the residence time of the perfusion fluid in the closed subcutaneous cavity, and (iii) at least one parameter for sending the perfusion fluid out of the closed subcutaneous cavity. (b) The controller is configured to pump the perfusion fluid from the perfusion fluid source through the fluid conduit to the closed subcutaneous cavity according to the parameters for sending the perfusion fluid to the closed subcutaneous cavity, (c) The controller is configured to allow the permeating fluid to remain in the closed subcutaneous cavity according to the parameter relating to the residence time, (d) The permeation system according to claim 1, wherein the controller is configured to pump the permeation fluid out of the closed subcutaneous cavity according to the parameters for pumping the permeation fluid out of the closed subcutaneous cavity.

3. The perfusion system according to claim 2, further comprising a perfusion fluid outlet, wherein the controller is configured to pump the perfusion fluid from the closed subcutaneous cavity through the fluid conduit to the perfusion fluid outlet according to the parameters for sending the perfusion fluid from the closed subcutaneous cavity.

4. The perfusion system according to claim 3, further comprising a fluid outlet valve located along a fluid path between the perfusion fluid outlet and the pump, wherein the controller is configured to open the fluid outlet valve when the pump delivers the perfusion fluid from the closed subcutaneous cavity.

5. The permeation system according to claim 4, wherein the controller is configured to close the fluid outlet valve when the pump delivers the permeation fluid from the permeation fluid supply source through the fluid conduit.

6. The permeation system according to claim 5, wherein the permeation fluid supply source is a permeation fluid supply source container, and the permeation fluid outlet is a permeation fluid outlet container.

7. The permeation system according to claim 3, wherein the elongated fluid conduit has a distal end configured to be implanted in the closed subcutaneous cavity, and the permeation system further comprises a passive drain outlet communicating with the elongated fluid conduit between the distal end of the elongated fluid conduit and the pump.

8. The permeation system according to claim 7, further comprising a passive drain valve communicating with the passive drain outlet, wherein the controller is configured to open the passive drain valve when the permeation system is in a passive drain state.

9. The controller is configured to close the passive drain valve when the pump delivers the permeation fluid from the closed subcutaneous cavity. The permeation system according to claim 8, wherein the controller is configured to close the passive drain valve when the pump delivers the permeation fluid from the permeation fluid supply source through the fluid conduit.

10. The perfusion system according to claim 8, wherein the perfusion treatment program includes at least one parameter relating to the passive drainage of the closed subcutaneous cavity.

11. The system according to claim 2, wherein the controller includes at least one input unit for selecting the perfusion processing program.

12. The system according to claim 11, wherein the input unit is configured to enable the selection of a perfusion treatment program from a plurality of pre-programmed perfusion treatment programs.

13. The system according to claim 11, wherein the input unit is configured to enable input of a custom permeation processing program.

14. The system according to claim 11, wherein the perfusion treatment program further includes at least one parameter that specifies the total number of cycles or total time of the perfusion treatment program.

15. The system according to claim 11, further comprising a drug supply source, wherein the controller is configured to deliver the drug from the drug supply source through the fluid conduit to the closed subcutaneous cavity by the pump, according to parameters for delivering the drug to the closed subcutaneous cavity.

16. The system according to claim 11, wherein the fluid conduit is a multi-lumen catheter including a first lumen and a second lumen.

17. The system according to claim 16, wherein the system is configured to deliver the perfusion fluid and the drug through the first lumen to the closed subcutaneous cavity, and to deliver the perfusion fluid from the closed subcutaneous cavity through the first lumen.

18. The system according to claim 16, wherein the energy transfer member extends through the second lumen.

19. The system according to claim 18, further comprising an ultrasonic transducer connected to the energy transfer member.

20. The system according to claim 16, wherein the light transmission member extends through the second lumen.

21. The system according to claim 20, further comprising a light source connected to the light transmission member, wherein the light source is configured to supply light having one or more wavelengths in the range of 350 nm to 450 nm to the light transmission member.

22. The system according to claim 11, wherein the pump, the perfusion fluid supply source, and the controller are housed in a mountable pump unit, the mountable pump unit further comprises a drain container configured to receive perfusion fluid supplied from the closed subcutaneous housing, and the mountable pump unit further comprises an energy source configured to operate the pump.

23. A method for addressing the risk of infection in a subcutaneous cavity closed by a perfusion system, (a) implanting an elongated fluid conduit such that the fluid conduit communicates with the closed subcutaneous cavity, (b) Operating the perfusion system according to a perfusion processing program that includes at least one parameter for delivering the perfusion fluid to the closed subcutaneous cavity, at least one parameter for the residence time of the perfusion fluid in the closed subcutaneous cavity, and at least one parameter for delivering the perfusion fluid out of the closed subcutaneous cavity. It includes, Operating the permeation system according to the aforementioned permeation processing program means that (i) Sending the perfusion fluid from the perfusion fluid source through the fluid conduit to the closed subcutaneous cavity according to the parameters for sending the perfusion fluid to the closed subcutaneous cavity, (ii) To enable the retention of the permeating fluid in the closed subcutaneous cavity according to the parameter relating to the residence time, (iii) The permeating fluid is delivered from the closed subcutaneous cavity through the fluid conduit according to the parameters for delivering the permeating fluid from the closed subcutaneous cavity. Methods that include...

24. The aforementioned permeation system includes a configurable pump and valve configuration. When the perfusion fluid is delivered from the perfusion fluid supply source to the closed subcutaneous cavity, the perfusion system is configured such that the configurable pump and valve configuration is set to a first state in which fluid flow is allowed between the perfusion fluid supply source and the pump, and fluid flow is prevented between the pump and the perfusion fluid outlet. The method according to claim 23, wherein, when delivering the perfusion fluid from the closed subcutaneous cavity to the perfusion fluid outlet, the perfusion system is configured to bring the configurable pump and valve configuration to a second state in which the flow of fluid between the perfusion fluid source and the pump is prevented, and the flow of fluid between the pump and the perfusion fluid outlet is enabled.

25. Before operating the perfusion system according to the perfusion treatment program, the resident fluid is drawn out of the closed subcutaneous cavity using the implanted elongated fluid conduit. The method according to claim 23, further comprising:

26. The method according to claim 25, wherein the perfusion system is configured to quantify the amount of perfusion fluid delivered to the closed subcutaneous cavity, and the perfusion system is configured to quantify the amount of perfusion fluid delivered from the closed subcutaneous cavity.

27. The method according to claim 26, wherein operating the perfusion system in accordance with the perfusion processing program further includes sending an adjusted amount of the perfusion fluid to the closed subcutaneous cavity according to the quantified amount of perfusion fluid that has been sent to the closed subcutaneous cavity up to that point, and the quantified amount of perfusion fluid that has been sent out of the closed subcutaneous cavity up to that point.

28. The method according to claim 25, wherein operating the perfusion system further comprises using the perfusion system to measure the pressure in the closed subcutaneous cavity.

29. The method according to claim 28, wherein the system is configured to adjust the operation of the permeation system in response to the measured pressure in the closed subcutaneous cavity.

30. The method according to claim 23, further comprising selecting the perfusion treatment program.

31. The method according to claim 30, wherein the selection of the perfusion treatment program includes selecting from a plurality of pre-programmed perfusion treatment programs.

32. The method according to claim 30, wherein selecting the perfusion treatment program includes inputting a custom perfusion treatment program.

33. The method according to claim 30, wherein the perfusion treatment program further includes at least one parameter that specifies the total number of cycles or total time of the perfusion treatment program.

34. The method according to claim 30, wherein the perfusion treatment program further comprises at least one of (i) at least one parameter for delivering a drug to the closed subcutaneous cavity, (ii) at least one parameter for delivering mechanical, electrical, or ultrasonic energy to improve the fluid flow within the closed subcutaneous cavity, and (iii) at least one parameter for delivering antimicrobial light to the closed subcutaneous cavity.

35. The method according to claim 30, wherein the delivery of the perfusion fluid to and from the closed subcutaneous cavity is not performed in an operating room environment.

36. The method according to claim 30, wherein the perfusion fluid is intermittently delivered to and from the closed subcutaneous cavity over a period of time at least eight hours.

37. The method according to claim 30, wherein the perfusion fluid is intermittently delivered to and from the closed subcutaneous cavity over a period of time at least 24 hours.

38. The method according to claim 30, wherein the perfusion fluid is delivered to the closed subcutaneous cavity at a flow rate of less than 20 mL / second.

39. The method according to claim 38, wherein the perfusion fluid is delivered to the closed subcutaneous cavity at a flow rate of less than 10 mL / second.

40. The method according to claim 38, wherein the perfusion fluid is delivered to the closed subcutaneous cavity at a pressure at the outlet of the fluid conduit which is less than 200 pounds per square inch.

41. The method according to claim 38, wherein the perfusion fluid is delivered to the closed subcutaneous cavity at a pressure at the outlet of the fluid conduit which is less than 100 pounds per square inch.

42. The method according to claim 30, wherein the closed subcutaneous cavity is a joint capsule, seroma, abscess, or wound.

43. Delivering the drug from the drug supply source through the fluid conduit to the closed subcutaneous cavity. The method according to claim 30, further comprising:

44. The method according to claim 43, wherein the agent comprises at least one of an antibiotic and an antibiofilm agent.

45. The method according to claim 43, wherein the fluid conduit is a multi-lumen catheter including a first lumen and a second lumen.

46. The method according to claim 45, wherein the perfusion fluid and the drug are delivered through the first lumen to the closed subcutaneous cavity, and the perfusion fluid is delivered from the closed subcutaneous cavity through the first lumen.

47. The method according to claim 45, wherein the energy transfer member extends through the second lumen.

48. To transmit mechanical, electrical, or ultrasonic energy to the closed subcutaneous cavity via the mechanical energy transmission member. The method according to claim 47, further comprising:

49. To transmit mechanical, electrical, or ultrasonic energy to the closed subcutaneous cavity via the energy transfer member so that particles are suspended in the perfusation fluid and subsequently sent together with the perfusation fluid through the fluid conduit to the drain. The method according to claim 47, further comprising:

50. The method according to claim 49, wherein the ultrasonic transducer is mechanically in contact with the energy transfer member.

51. The method according to claim 50, wherein the ultrasonic transducer operates at a frequency in the range of 10 kHz to 1000 kHz such that particles are suspended in the perfusion fluid.

52. The method according to claim 50, wherein the ultrasonic transducer operates at a frequency in the range of 10 kHz to 100 kHz so that particles are suspended in the perfusion fluid.

53. The method according to claim 50, wherein the ultrasonic transducer operates at a frequency in the range of 10 kHz to 50 kHz such that particles are suspended in the perfusion fluid.

54. The method according to claim 45, wherein a light-transmitting member extends through the second lumen, the light-transmitting member is connected to a light source, and the method further comprises transmitting light through the second lumen to the closed subcutaneous cavity.

55. The method according to claim 54, wherein the transmitted light has a frequency in the range of 350 to 450 nanometers.

56. The method according to claim 55, wherein the multi-lumen catheter further comprises a third lumen, the first lumen configured to transport the perfusion fluid to and from the closed subcutaneous cavity, the second lumen configured to transport ultrasonic energy to the closed subcutaneous cavity, and the third lumen configured to transport light energy to the closed subcutaneous cavity.

57. (i) delivering ultrasonic energy to the closed subcutaneous cavity via a mechanical energy transmission member extending along the fluid conduit, and (2) delivering at least one of optical energy to the closed subcutaneous cavity via an optical energy transmission member extending along the fluid conduit. The method according to claim 45, further comprising:

58. The method according to claim 30, wherein the permeating fluid is supplied from a mounted pump unit.

59. The method according to claim 58, wherein the mounted pump unit comprises (i) a pump, (ii) a perfusion fluid container, (iii) a drainage container, and (iv) a pump energy source, wherein in a first operating mode, the pump is configured to deliver the perfusion fluid from the perfusion fluid container through the fluid conduit to the closed subcutaneous cavity, and in a second operating mode, the pump is configured to deliver the perfusion fluid from the closed subcutaneous cavity through the fluid conduit to the drainage container.

60. The aforementioned permeable fluid container is replaced periodically. The method according to claim 59, further comprising:

61. The method according to claim 59, wherein the perfusion fluid container has a fluid holding volume of less than 1050 mL.

62. The method according to claim 59, wherein the mounted pump unit further comprises a controller configured to control the operation of the pump.

63. The method according to claim 62, wherein the controller is further configured to control the operation of at least one of the ultrasonic component and the blue light component attached to the mounted pump unit.

64. The method according to claim 63, wherein the controller is further configured to periodically operate at least one of the pump, the ultrasonic component, and the blue light component according to a pre-programmed schedule.

65. The method according to claim 30, wherein implanting the elongated fluid conduit, and delivering the perfusion fluid to and from the closed subcutaneous cavity are performed postoperatively, and the surgery includes perfusion and debridement procedures performed in the closed subcutaneous cavity.

66. The method according to claim 30, wherein the implantation of the elongated fluid conduit, the delivery of the perfusion fluid to the closed subcutaneous cavity, and the delivery from the closed subcutaneous cavity are performed after a suction treatment of the closed subcutaneous cavity.

67. The method according to claim 30, wherein the fluid conduit is a surgical drain.

68. A perfusion system for addressing the risk of infection in closed subcutaneous cavities, (a) an elongated fluid conduit configured to be implanted in a closed subcutaneous cavity, (b) A pump configured to deliver the permeating fluid through the elongated fluid conduit, (c) Perfusible fluid supply source and (d) A controller configured to operate the perfusion system according to a perfusion processing program including (i) at least one parameter for delivering the perfusion fluid to the closed subcutaneous cavity, (ii) at least one parameter relating to the residence time of the perfusion fluid in the closed subcutaneous cavity, and (iii) at least one parameter for delivering the perfusion fluid out of the closed subcutaneous cavity. It is equipped with, (e) The controller is configured to send the perfusion fluid from the perfusion fluid source through the fluid conduit to the closed subcutaneous cavity by the pump, according to the parameters for sending the perfusion fluid to the closed subcutaneous cavity, (f) The controller is configured to allow the permeating fluid to remain in the closed subcutaneous cavity according to the parameter relating to the residence time, (g) A perfusion system in which the controller is configured to pump the perfusion fluid out of the closed subcutaneous cavity according to the parameters for pumping the perfusion fluid out of the closed subcutaneous cavity.

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