System and method for locating a leak in an organ within a body cavity

Abstract

The present invention concerns a system for locating an organ wall defect or the origin of an anastomotic / suture line leak during or after surgery, in a positive pressurized body cavity. Said system (1) mainly comprises i) a handheld body or part or housing (2) which is connected to a gas intake or delivery line (3) allowing gas to flow through it from its free tip (3') and is intended to be inserted into the body cavity and being moved around inside it, ii) a measurement unit (4) comprising at least one sensor means (5) able to measure at least one gas property and which preferably also comprises, or is associated or working with, at least some computational means (5') and / or advantageously sensory feedback means (5''), and iii) a back gas line or second gas delivery tube (6) which connects the exit of the measurement unit (4) to the body cavity (BC), the system (1) thus providing a continuous gas flow loop between the body cavity and the measurement unit (4), with said back line allowing advantageously equalization of the gas pressure / flow between the inlet and the outlet of said measurement unit (4).

Description

[0001] System and method for locating a leak in an organ within a body cavity

[0002] FIELD OF INVENTION

[0003] The present disclosure generally relates to the detection of perforations in organ walls and concerns a system and a method for detecting and above all locating defects, perforations and leaks in an internal organ of a patient.

[0004] In particular, the present disclosure describes a method, system and device for locating a leak caused by incomplete organ closure, an organ wall defect or the origin of an anastomotic / suture line leak during surgery, in a positive pressurized body cavity that is insufflated to substantially extend a body cavity and / or internal lumen.

[0005] BACKGROUND OF THE INVENTION

[0006] Surgical techniques including laparoscopic surgery, robotic-assisted laparoscopic surgery, cardiothoracic surgery, thoracic surgery, and open surgery require precise organ closure techniques. Typically, the surgeon enters a cavity to perform a procedure on a desired organ. This involves gaining access to the organ, body cavity or lumen by means of surgical incision. Upon completion of the procedure, the incision is closed. Failing to close the incision can lead to adverse consequences such as internal bleeding or infection. For this reason, it is often desired to minimize the invasiveness of surgical procedures.

[0007] For example, surgical laparoscopy is one of the main techniques for minimally-invasive surgical (MIS) procedures, performed in the abdomen or pelvis using small incisions (usually 0.5-1.5 cm) with the aid of a long fiber optic cable system with camera for diagnosis or therapeutic interventions. Laparoscopy is an alternative approach to traditional open surgery, laparoscopic surgery has shown to provide better post-operative outcomes of reduced pain due to smaller incisions for the patients, with shorter hospital stays and decreased postoperative complications, and better economic results for healthcare organizations.

[0008] Laparoscopy is a mature surgical technique relying on standardized workflows and equipment. The most critical equipment, which is a laparoscopic insufflator is a standard piece of operating room (OR) equipment used to inject CO2 into the peritoneal cavity and to maintain user defined pressure during the entire surgical procedure.

[0009] In general, the basic essential equipment for any laparoscopic procedure includes: a laparoscopic insufflator - for CO2 insufflation in the abdomen cavity to create working space and organs separation to allow for the surgical procedures; an optical system with camera and light source for visualization inside of the abdominal cavity; and a video monitor for displaying what is captured by the camera. In addition to this equipment other single use instruments are often employed such as: a Veress needle - for initial abdominal cavity insufflation; trocars - to serve as access ports for surgical instruments; gas insufflation tubing set - to allow for gas insufflation and pressure sensing; linear and circular staplers to cut, seal, and reconnect tissues; equipment; and instruments for manipulation of the organs and equipment;

[0010] A typical procedure commences with the administration of general anesthesia of the patient. Thereafter, the insufflator is inserted into the patient. The patient’s peritoneal cavity is insufflated with CO2 via the insertion of a Veress needle or an initial laparoscopic trocar to help establish pneumoperitoneum to a target pressure (usually between 8 to 15 mm Hg). This pneumoperitoneum creates the workspace needed to perform the procedure. Once the target pneumoperitoneum or abdominal pressure is achieved, additional working ports called trocars (ranges from 5 mm to 15 mm in diameter) are inserted through small incisions into the patient’s abdominal wall. Through these trocars a camera and operating instruments can be inserted and manipulated during the procedures. The target abdominal pressure is maintained throughout the procedure to allow for organs separation and provide visibility and safe operating space.

[0011] One severe complication associated with surgery is leaks in the organ caused by defects in the organ walls. This can happen in hollow organs, such as the esophagus, stomach, lungs, heart, large and small bowel, rectum, and bladder. Organ wall leaks often result in devastating consequences for the patient including sepsis, peritonitis, increased cancer recurrence as well as re-operation and death.

[0012] There are a variety of factors which can result in leaks. The risk for a potential leak increases when multiple organ closures must be created, or multiple staplers are utilized. Intraoperative leaks are mechanical leaks, usually caused by technical failure due to incomplete organ closure at the end of the procedure possibly due to stapler failures, tissue trauma or incomplete suturing or stapling. This type of leak is potentially avoidable and could be identified intraoperatively with appropriate leak testing.

[0013] Previously described systems and methods, which are gas-based leak detection systems, are useful in the detection of the presence or absence of leaks during the surgery, but do not provide a way to locate those leaks. In particular, US11357932 (B2), US2019046742 (Al), WO2021123012 (Al), of the present applicant (also referred to as QI, Q2 and Q3 herein), disclose methods and systems with the aim to detect the presence or absence of a medically relevant incomplete organ closure (s). The test outcomes allow surgeons to perform follow up steps when necessary (such as adding additional stitches or surgical clips to close the hole in the organ, or redo of the entire anastomosis .... etc.). While the described methods and systems provide a repeatable, reliable, and easy leak test workflow, it may still be difficult to localize the site of the defect after a positive leak test is performed. While the inventions described in prior art (QI, Q2, Q3) provide a reliable and efficient way of detecting the presence of a hole by creating a controlled differential pressure (delta P) environment between the pressure in the test organ and pressure in the outside body cavity thus facilitating a “leak” to be detected through any potential incomplete organ closure. This also provides an ideal environment for which the location of a leak could be identified. The disclosures of these three documents QI (US11357932 (B2), Q2 (US2019046742 (Al), Q3 (WO2021123012), are enclosed herein by reference, in particular concerning the constitution and functioning of an intraoperative leak detection system.

[0014] Different known methods are the current surgical standard used by clinicians to locate an incomplete organ closure in surgery. One method, often referred to as an “air bubble test’ relies on injecting a gas into the hollow organ typically using a syringe, a handheld pump, or an endoscope. The insufflated test organ is then submerged in saline solution (water bath) within the abdomen cavity. The presence of air bubbles signifies a leak. This technique requires full submersion in order to detect the leak. But organ submersion is not possible in some organ locations (i.e., right colon / stomach, or lungs). It requires handling of saline solution which can greatly increase the time of operating room procedures, for example, to fill the cavity with saline solution, to empty the saline solution at the end.

[0015] Regardless of the presence of a leak, the detection sensitivity depends on the pressure in the test organ being sufficiently higher than the pressure in the abdominal cavity such that the gas can flow through the hole and create “bubbles”. Other interference (“bubbles” could be present due to other confounding factors (e.g., trapped gas in between the tissue planes which is released due to manipulation thus producing false “air bubbles”). Visualization of the air bubbles could also be difficult, as the saline solution is often tinted red due to the presence of blood.

[0016] Another technique is the color dye test. Colored dye such as methylene blue is injected into the target organ, usually the stomach or the rectum. The outside of the organ is then inspected in an attempt to identify the presence of the colored dye to indicate the presence of a leak. The dye test is possible only for some organs and often difficult to perform as it often relies on injection of a large volume of fluid.

[0017] A limitation of this technique is that filling of dye solution is not possible in some organ locations (i.e., right colon), repeated tests are difficult due to color staining of the organ and surrounding tissues after the 1st positive leak test. The dye test is time consuming with each test requiring the filling and removal of the colored dye from the organ through a tube. Also visualizing of the colored dye (e.g., methylene blue) in organs stained with blood is not always easy. In case of a large hole, or an organ with multiple leaks, a large area of the organ could be stained in blue, making localization difficult or impossible. Additionally, a small hole in a nondependent location within the organ may be difficult to identify if insufficient volume of fluid is injected.

[0018] Yet another existing technique is the use of visual inspection or surgical imaging techniques. For example, intraoperative endoscopy relies on the use of a flexible endoscope to perform visual inspection of the anastomosis site internally. It requires an endoscopist or a second surgeon to be available at the end of the surgery. It is commonly used when air bubble test or the color dye tests cannot be performed or to examine the anastomosis for other complications (e.g., bleeding).

[0019] This technique is costly in terms of materials, personnel, and is not always available in the operating room (OR). Visual inspection can be time consuming, subjective, and potentially have low visibility due to poor bowel preparation or retained gastric contents. Note that other inspections are possible, such as visual inspection from outside of the organ in open or laparoscopic surgery, or other diagnostic imaging techniques (e.g., CT scan), which require expensive imaging tools. The test has variable sensitivity, depends on user experience, time consuming and required an imaging tool which is not always available in the OR. Visualization of small holes could be difficult or impossible and may only be detectable in the presence of positive internal pressure.

[0020] The focus of the current invention is to locate an organ wall defect in a hollow organ, such as incomplete organ wall closure, organ perforation during the surgery, or any pre-existing organ perforation.

[0021] SUMMARY OF THE INVENTION

[0022] The invention concerns a system for primarily locating an incomplete organ closure, an organ wall defect or the origin of an anastomotic / suture line leak (i.e. locating a defect creating a leak) during or after surgery, in a positive pressurized body cavity, i.e. with a substantially extended body cavity and organ lumen insufflation.

[0023] According to a first aspect, the system of the invention comprises a handheld body or part or housing which is connected (preferably mechanically and fluidly) to a gas intake or delivery line, preferably a long hollow probe. Said hollow probe forms a front gas delivery tube which allows gas to flow through it from its free tip and is intended to be inserted in the body cavity and being moved around inside it (by the user or operator during the search for locations of leaks or wall defects, applying advantageously a localization process by progressive guided approach). The invention also comprises a measurement unit or means containing at least one sensor means able to measure at least one gas property, such as a gas flow sensor, a gas concentration sensor and / or gas pressure sensor, or a combination of at least two such sensors. Said measurement unit or means preferably also comprises, or is associated or working with, at least some computational means (for example a micro-controller or similar electronic means with embedded software, and preferably with real time processing capacity) and advantageously also some sensory feedback means (to the user or operator). The sampled gas flowing through the front gas delivery tube reaches the entry of the measurement unit through the front gas delivery tube.

[0024] Furthermore, the aforementioned system also comprises a back gas line or second gas delivery tube which connects the exit of the measurement unit to the body cavity. Thus, a continuous gas flow loop is formed between the body cavity and the measurement unit and said back line allows advantageously equalization of the gas pressure / flow between the inlet and the outlet of the measurement unit.

[0025] This system or device of the invention is also designated as “leak locator” in the following specification.

[0026] According to another possible aspect of the invention, the inventive device is a standalone, self-sufficient and / or with autonomous operation device.

[0027] According to another possible aspect of the invention, the inventive device is associated with leak detection systems such as the one disclosed in WO2021123012 (incorporated herein by reference), or an equivalent leak detection system, as a separate yet connected device, or as a partly integrated device (for example for its measurement and / or computational means, which could be shared with said system).

[0028] Such a system (according to WO2021123012 in particular) allows for automatically detecting a clinically relevant leak and / or inadequate closure following a medical procedure, in an at least partially hollow organ or mutually fluidly connected hollow organs, residing in the interior volume of a body cavity. It comprises at least: injection means designed for controlled injection of a specific test gas, or a gas mixture containing at least one test gas, into said organ(s), said injection means comprising or being associated with first gas pressure measuring means, detection means designed for analyzing the gas mixture and in particular measuring the concentration of test gas, in the interior volume of the body cavity or at least in the space adjacent to said organ(s), and possibly the gas pressure within said volume or space, computational means designed for managing the injection and detection means, for storing and retrieving data from an integrated local or remote database and for analyzing data and evaluating the likelihood of the presence of a leak or of the existence of a faulty closure, and its degree of severity, by comparing stored and real-time data. Said computational means are linked to sensor means allowing to determine the pressure difference between the interior of the hollow organ(s) and the adjacent space or interior volume of the body cavity, said computational means controlling or mastering said pressure difference by driving accordingly associated injection and / or suction means, incorporating said test gas injection means. It comprises, in addition to the test gas injection means, also filling gas injection means designed for injecting in a controlled manner a filling gas into the interior volume of the body cavity. Said document also discloses in particular flow control means, pressure sensors, gas evacuation / suction means and insufflator(s) integrated or associated with said system. These means are configured so that the pressure difference between organ and cavity is maintained constant during measurement windows, advantageously at a set value.

[0029] According to another possible aspect of the invention, the measurement unit or means are fitted, embedded or mounted in the hollow handheld body or part or housing, possibly together with computational means and / or sensory feedback means.

[0030] According to another possible aspect of the invention, the measurement unit or means, possibly together with computational means and / or sensory feedback means, are integrated, contained in or part of the central unit or module of a leak detection system as described in W02021123012 or of a similar gas-based leak detection system.

[0031] According to other possible aspects of the invention:

[0032] - the tube forming the gas intake probe (3) may comprise a single channel (8) leading to the opening at the free end tip (3’) having an atraumatic shape;

[0033] - the tube forming the gas intake probe (3) may comprise at least two separate channels (8) leading to the opening at the free end tip (3’) having an atraumatic shape, each channel being connected to a different sensor means (5);

[0034] - the tube forming the gas intake probe (3) may comprise four channels (8) dividing said tube internally along its length, each channel being connected to a different sensor means (5).

[0035] According to a further aspect, the invention also concerns a method for locating an incomplete organ closure, an organ wall defect or the origin of a anastomotic / suture line leak during or after surgery, in a positive pressurized body cavity, i.e. with a substantially extended body cavity and organ lumen insufflation, said method mainly consisting in providing a leak location system as mentioned before, and using said system to locate leaks by inserting the rigid or semi-rigid long hollow probe of the gas intake or delivery line (3) into the abdominal cavity lodging the concerned organ, moving said probe around in the cavity and along the organ wall, and exploiting the measurement signal delivered by said system, either directly or as a sensory feedback signal to locate a leak.

[0036] When the system according to the present invention is a standalone and autonomous system, it may be envisaged not only to use it to locate a leak / defect in an organ, but possibly also, in a first approach, to detect the presence of such a leak / defect, independently of a specific leak detection system (and then locate precisely the defect / leak in a second phase).

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIGURE 1 is a schematic diagram which depicts the general placement of instruments during a laparoscopic surgical procedure, including the “leak locator” system of the present invention.

[0039] FIGURE 2 is schematic depiction of a flow of gas through an organ wall as will be detected by aspects of the present disclosure.

[0040] FIGURE 3 is a schematic drawing of the general layout of the system (leak locator) of the present invention.

[0041] FIGURE 4 is a schematic drawing of the system according to a first embodiment of the system of the present invention, with the measurement unit / means in a housing separate from the housing of the handheld and manually operable housing attached to the gas intake probe.

[0042] FIGURE 5 is a is a drawing of the same embodiment as figure 4 with explanatory captions.

[0043] FIGURE 6 is a schematic drawing of the system according to a second embodiment of the system of the present invention, with the measurement unit / means integrated into the module / housing of a gas-based leak detection system, such as the aforementioned “leak detection system” of the applicant.

[0044] FIGURE 7 is a is a drawing of the same embodiment as figure 6 with explanatory captions.

[0045] FIGURE 8 is a schematic drawing of the system according to a third embodiment of the system of the present invention, with the measurement unit / means embedded / integrated in the handheld and manually operable housing attached to the gas intake probe.

[0046] FIGURE 9 is a is a drawing of the same embodiment as figure 8 with explanatory captions. FIGURE 11 is a chronogram of the measurement signal provided by the system as the tip of the gas intake probe of the leak locator system is moved around and along the inspected organ wall, said representation also showing the pre-set threshold values and the associated user feedback levels in the form of auditory outputs.

[0047] FIGURE 12 is another chronogram of the measurement signal provided by the system as the tip of the gas intake probe of the leak locator system is moved around and along the inspected organ wall, indicating phases when the tip rests on a leak location (big box) and when the tip passes over a leak location (small boxes).

[0048] FIGURE 13A and FIGURE 13B are two similar partial longitudinal cross-sectional views of the gas intake probe of the system according to the invention (one gas flow channel), showing two alternate embodiments of the tip of the probe.

[0049] FIGURE 14 is a schematic drawing as a sectional view along a plane perpendicular to the longitudinal axis of the gas intake probe of the system according to the invention, showing four parallel channels subdividing the interior of the tube of said probe.

[0050] As illustrated schematically on figures 1 and 2, the leak localization concept (system and method) of the present invention is based on the scientific principle of gas diffusion across a pressure gradient from a high-pressure region (in the organ, for example - 15 mmHg) to a low- pressure region (in the abdominal cavity_12 mmHg). This principle is used also in the leak detection of other systems developed by the inventors / applicant (see QI (US 11357932 (B2), Q2 (US2019046742 (Al), Q3 (WO2021123012)). In figure 1, one can notice that several trocars (9) allow the access to the body cavity (BC) and to the inside of the hollow organ (HO) for the gas lines (intake and back) of the system (1), the insufflation lines (15, 15’) for cavity and organ (CO2) and for an optional endoscope / camera (14). In this set-up the leak locator system (1) is connected via a sensor cable (13) (data transmission) to the leak detecting system (7), for example as described in W02021 / 123012.

[0051] After the presence of a leak is confirmed by the inventors / applicant existing systems, such as the one disclosed in U.S. Patent Nol 1,357,932 or W02021 / 123012 for example, the underlying system functions to set the ideal operating environment for leak localization. This environment is similar to that of leak detection: where the test organ is being insufflated with a test gas to a target pressure that is higher than the pressure in the surrounding cavity. After positive leak detection, the user will be tracing the anastomosis with the tip of the probe, an instant alert will be issued when the tip is on a leak, the user marks the leak location with built- in adequate means, the user repairs the leak with adequate means and retests with the leak detecting system. As can be seen on figure 2, at the leak location, the gas flow at and around the organ wall defect will be higher compared to the gas flow in the cavity further away from the organ wall defect, and theoretically should provide a way to locate such a defect. However, the fluid dynamics within the abdominal cavity during laparoscopic surgery are highly complex and turbulent. Active CO2 insufflation from the insufflator continuously perturbs intra-abdominal pressures, while the patient’s respiratory cycle introduces additional periodic fluctuations. Together, these factors generate a highly variable, non-stationary flow environment characterized by spatial and temporal fluctuations in intra-abdominal gas distribution. Such instability renders leak localization inherently challenging, as detection methods based solely on pressure or flow perturbations are prone to high false-positive rates. Under these conditions, the resulting signals based on a simple detection of flow or pressure would be highly reliability and clinical interpretability.

[0052] The present invention overcomes the above challenges and drawbacks to provide an accurate, precise and reliable localization of leaks, in the operating environment of the cavity with highly complex and turbulent flow and pressure dynamics.

[0053] According to the invention, there is provided a system (1) for locating an incomplete organ closure, an organ (HO) wall defect or the origin of an anastomotic / suture line leak during or after surgery, in a positive pressurized body cavity (BC), i.e. with a substantially extended body cavity and organ lumen insufflation.

[0054] As shown in the form of non-limitative examples in figures 3 to 9, said system (1) mainly comprises: i) a handheld body or part or housing (2) which is connected, preferably mechanically and fluidly, to a gas intake or delivery line (3), preferably a rigid or semi-rigid long hollow probe, which forms a front gas delivery tube allowing gas to flow through it from its free tip (3’) and is intended to be inserted into the body cavity and being moved around inside it, ii) a measurement unit or means (4) comprising at least one sensor means (5) able to measure continuously at least one gas property, such as for example a gas flow with a gas flow sensor, a gas concentration sensor and / or gas pressure sensor, or a combination of at least two such sensors. Preferably the sensor is configured in an in-line arrangement with one gas inlet and one gas outlet, enabling continuous measurement of the gas stream as it passes through the device. Depending on the sensing modality, the system quantifies: Flow by detecting pressure or velocity differences across the inlet and outlet; Pressure by measuring absolute or differential pressure at one or both ports; Gas concentration by comparing chemical or optical signals between the entering and exiting gas streams. In each case, the inlet-outlet configuration ensures that the measured parameter reflects the real-time dynamics of gas exchange across the system, providing a basis for volumetric flow, pressure regulation, or detection of trace gases.

[0055] With the above, which preferably also comprises, or is associated or working with, at least some computational means (5’) and / or advantageously sensory feedback means (5”), and iii) a back gas line or second gas delivery tube (6) which connects the exit of the measurement unit (4) to the body cavity, the system (1) thus providing a continuous gas flow loop between the body cavity and the measurement unit (4), with said back line acting as a gas pressure / flow equalization line, and allowing advantageously equalization of the complex and turbulent gas pressure or flow, or gas concentration between the inlet and the outlet of said measurement unit (4).

[0056] The system (1) that detects the gaseous leaks depicted above (see in particular figure 3) comprises a hand-held device / housing (2) with a long hollow probe (3) (rigid or semi-flexible) and the overall design which resembles a typical laparoscopic suction and irrigation device that can be inserted into the peritoneal cavity via a trocar channel (and is connected to the entry of the measurement unit through a flexible conduit / tube).

[0057] The leak locator body is the handheld part (2) that is connected to a front gas delivery tube 1 (3) which allow gas to flow through its body (tube channel) from the tip (3’) of the hollow probe, reach to the entry of the measurements unit (4) containing at least a flow sensor / gas pressure sensor (5), which are connected to the central computational unit (5’). The handheld hollow device also consists of a back gas line - gas delivery tube 2 (6), which connects to the abdomen cavity through a luer lock of a trocar (9) for example: thus, a continuous gas flow loop is formed. In particular, the back gas line (6) allows the equalization of the gas pressure / flow between the inlet to the gas measurement unit, and the outlet of the gas measurement unit.

[0058] Under the control of the user (surgeon) holding and manipulating the long probe, the tip of the “leak locator” can be moved freely inside the body cavity (just like they would use for a laparoscopic suction and irrigation device - familiar gestures with no learning curve), to go near or further away from the target test organ. The user could bring the tip of the leak locator close and onto the organ, and trace along the suture / staple line of the test organ. This will allow gas sampling via the tip of the leak locator probe, via the gas line, and measurement of the sampled gas properties by the gas sensing unit. These local gas sampling measurements are recorded, stored in the central unit of the system or of the connected / cooperating leak detection system (7) for further processing, and provide real-time sensory outputs to provide feedback to the user to provide information related to the proximity of the tip of the leak locator and the leak. The continuous gas flow is a passive flow (Venturi effect) resulting from the positive pressure in the body cavity. The intensity of the flow (flow rate) is determined by the pressure of the abdominal cavity and is the result of the pressure in the abdominal cavity: if the cavity pressure is high, the passive flow will be relatively high; and vice versa for low pressure cavity. The passive flow allows substantial “equalization of common sources of background flow noise” in the cavity in order to reveal the leak related flow signal. If necessary, the flow may be controlled by controlling the pressure in the cavity. Nevertheless, there is no functional reason to control the pressure to that end as one of the main features of the invention is the presence of a back gas line (6) in order to equalize (or cancel) the pressure of the cavity.

[0059] In the presence of an organ wall defect, test gas continuously leaks into the peritoneal cavity through the organ wall defect / hole, the test gas concentration / flow / pressure, or other known gas properties changes that are resulted from the “leak location”, which is the origin of a leak, are the most extreme (highest) at location closest to the hole, than further away from the hole, where there is a relatively less extreme gas property change compared to the background gas properties. Regardless of the gas property measurement (i.e. gas composition, gas flow, pressure...etc) used as the measurement data, the working principle or core solution are similar.

[0060] In a positive pressure body cavity, the filled gas (i.e. CO2) provides no / little useful information for leak localization and acts as “background noise” for the purpose of the leak localization, and the filled gas actually superimposes and blended in with gas property changes resulted from the leak (signal of interest), making localization inaccurate / impossible. A leak is usually small, ±1 to 2mm, and is associated with small flow and pressure change that are difficult to detect. The smaller the hole / leak, the smaller the change in flow and pressure, and therefore more difficult to locate. A leak can be easily masked by the background filled CO2 gas due to continuous laparoscopic insufflation required to maintain the working space during the procedure.

[0061] In commonly known flow sensors or pressure sensors that have a fluid inlet and a fluid outlet, the measurement mechanism housed in between the fluid inlet and the fluid outlet computes the measurement differences between the fluid inlet and the fluid outlet to provide the flow or pressure information. The fluid outlets of these sensors are usually connected to room exit, which is the atmospheric pressure / flow. (for example, like surgical insufflation). The flow and pressure measurements of surgical insufflators are relative to room / atmo spheric condition.

[0062] Under atmospheric pressure or in open surgery in which the test organ is insufflated with test gas and maintained at a constant desirable pressure, it is relatively effortless to locate a hole along the suture line using the described method / system above because the leak location generates a high / obvious gas properties change (locally high flow, pressure, test gas content, velocity... etc.) that can be easily and immediately distinguishable from the background or in this case the room / atmo spheric gas property. The signal of interest has a high signal to noise ratio and usually requires no further or minimal processing (i.e. standard signal filtering processes) to output sensitive localization information and therefore low false positive or false negative detection.

[0063] For example, when a mass flow sensor is used, a high peak or spike or heightened amplitude reflects the mass flow sensor detection, and hence the location of the hole. When away from the hole, the amplitudes of the background signal / noise are distinctively different from when the leak locator is on the hole. The same principle applies to other type of sensors measuring different gas properties such as pressure, flow, gas concentration... etc.

[0064] In laparoscopic surgery, there is constant positive pressure in the peritoneal cavity generating interference / noise signals, which makes the detection and separation of the signal of interest from noise more difficult, as they could overlap partially in ranges of amplitudes. To overcome this, the current invention contains a back gas line (B) connecting the fluid outlet of the gas sensing unit, to equalize or cancel the background filled gas noise (common gas properties) between the fluid inlet (tip of the leak locator) and fluid outlet of the gas sensing unit, so that the change in local gas properties as the result of a leak can be revealed, in realtime with less than ms delay, providing close to real-time detection with high spatial accuracy in which the user could pin-point the leak location with high precision.

[0065] The teaching of the present invention intends to overcome this problem and to extend the teaching of documents QI to Q3, and other gas-based leak localization methods:

[0066] - to provide an easy and accurate way to allow the user to use the leak locator device to do a close-up verification check on the organ closure integrity at suspected location (usually the suture or staple line) with no time constraint related to deterioration of test sensitivity over time (To expand on this, if we were to measure the concentration of a leak gas (i.e. oxygen), the concentration of the leak gas accumulates as leak progresses, and making detection less accurate as leak localization time goes);

[0067] - to identify multiple holes in the same test session

[0068] - provide information that will allow the computation to estimate and characterize the characteristics (size, length, width... etc) of the incomplete organ closure based on analysis of the detection signal; - to do a cross verification check to determine the likelihood of the presence of multiple holes based on the corresponding test result.

[0069] Other advantages of the invention over existing methods may comprise one or several of the following advantages:

[0070] - the invention should eliminate the use of a saline / color dye solution that changes the organ color or would adding extra OR time due to handling of the saline / dye solutions;

[0071] - it should allow repeatable leak localization tests without compromising test sensitivity;

[0072] - it should be easy to do and allows flexible way to re-do leak detection (after an organ hole fixed attempt) and the leak localization. This test sequence could be repeated multiple times with an easy workflow;

[0073] - the localization should have high temporal and spatial precision;

[0074] - the test results could be quantified;

[0075] - the test is sensitive for incomplete organ closures of different sizes (small ±0,05cm, big 1cm).

[0076] DETAILED DESCRIPTION OF EMBODIMENTS

[0077] As shown is figures 4 to 9, and depending on whether or not it is integrated in a leak detection system (and then share means with it), the gas measurement unit (4) may coordinate and manage leak locator system (1) control including the processing unit or computational means (5’), the gas sensor (5), the power supply (10), the sensory feedback means (5”), and memory means (11), where the measurement data is defined as the time series of measurement data recorded by the gas sensing unit (can include at least one gas sensor means 5, such as a flow sensor, a pressure sensor, or a gas sensor that measures at least one type of gas concentration that can be found in the leak gas in the test organ) through the handheld (leak locator) device controlled by the user.

[0078] Such processing unit (5’), can consist of a micro-controller to receive real-time measurement data from the gas sensing unit (5), with real-time signal processing capability. When the input gas measurement signals surpasses a pre-defined and pre-set threshold value(s) - ( for example flow measurements > 0.2L / min, or pressure measurement of > 0.5mmHg) the sensory feedback unit (5”) is activated to provide real-time sensory feedback to the user to indicate when the tip (3’) of the gas delivery tube (3) is in close proximity of a leak. In the same example, if the measured flow is smaller than 0.2L / min, no sensory signal is given.

[0079] Furthermore, and as shown in figure 11, multiple pre-defined and preset threshold values could be set in systematic gradient way so that the sensory outputs given to the user correspond and reflect the distance between the tip of the leak locator and the hole. The distance is derived from the strength of the measurement signals, the stronger the measurement signals, the higher the sensory indication that the hole / defect is located in close proximity to the tip of the leak locator compared to a weaker measurement signal, which indicate a lower sensory indication that the hole is located in close proximity to the tip of the leak locator.

[0080] The sensory outputs vary according to the different pre-defined and pre-set threshold value(s), in a systematic manner, so that a higher sensory outputs, for example, for auditory outputs, the level of sound in dB is higher for a higher level of predefined threshold value, compared to the level of sound in dB for a lower level of predefined threshold value.

[0081] The pre-defined and pre-set threshold value(s) can be set by the user through the user interface (12) to vary for different clinical situations, such as depending on the estimated size of the organ wall defect (leak); the pressure in the abdominal cavity; the pressure in the hollow organ.

[0082] When associated with or at least partly integrated into a leak detection system (7), as described before, having its own central unit (7’) and storage means, other additional data could be used to improve the detection, this includes past measurement data from the corresponding leak test (positive leak test that lead to the leak localization in the same surgery), past database / measurement data capturing the leak localization tests, system operating parameters, and other user input information to allow for the computation and automatic or semi-automatic selection of the pre-defined set thresholds for the leak localization.

[0083] The pre-defined and pre-set detection threshold value(s) can be set by the user via the system user interface to adapt to different clinical situations. Or an optimal detection threshold value can be computed from the processing unit based on the previous positive leak test results that lead to the need to localize the leak in the associated organ. The unique input data from the “leak detection system” includes:

[0084] 1) all or part of the leak test results and leak tests related parameters (abdominal pressure, organ pressure, differential pressure differences between the abdomen and organ; measurement of the test gas concentration change over time, other system related parameters... etc); this package of information can be referred to as the corresponding “leak detection system” measurement values for the leak localization. These system measurement values can be used to derive the severity of the organ wall defect (leak) which is estimated based on 1) the “leak detection system” measurement values to grade the severity of a leak, this is a high gas leak concentration (i.e. 02 measurement goes from 0 to 3% in 1 minute using the leak detection method / system described in “leak detection” Q3 patent) signals a larger hole / leak ( higher severity) COMPARED to low gas leak concentration i.e. 02 gas measurement goes from 0 to 1% in 1 minute using the detection method described in “leak detection system” Q3 patent = smaller hole = lower severity).

[0085] To improve further the detection accuracy and sensitivity, during the leak localisation, other real-time “leak detection system” measurement values may be included, such as:

[0086] 2) the pressure in the abdominal cavity; and / or

[0087] 3) the pressure in the hallow organ is (are) used, processed and adapted accordingly to provide the optimal detection threshold value settings that will allow more reliable and sensitivity leak localization.

[0088] As can be noticed by comparing figures 4, 6 and 8, at least three practical constructions of the system according to the invention can be envisaged, depending on where the measurement unit (4) is lodged:

[0089] - in the handheld body / housing (2) of the system (l)-figures 4 and 5;

[0090] - in the central module / unit (7’) of the leak detection system (7) associated with the system (l)-figures 6 and 7;

[0091] - in a separate housing (2’), different from the handheld housing and from the housing of a leak detection system, figures 8 and 9.

[0092] In all three embodiments, the gas flow enters the measurement unit (4) through the gas intake / delivery line (3) connected to the body cavity (BC) and movable inside it, which allows gas property(ies) to be measured and recorded, and then passes out to the back gas line (6), which is connected to the cavity via a luer lock connection of a trocar (9).

[0093] Part of the said fluid delivery tube (3) can be inserted into the body cavity (BC) of the patient via a trocar (9) already placed and inserted into the body cavity of the patient during the surgery. The handheld body part (2) of the leak locator system (1) and part of the gas delivery tube (3) remains outside of the trocar.

[0094] Said gas intake / delivery tube (3) can be rigid, semi rigid, soft, or in a combination of rigid / semi-rigid / soft, generally made of medical grade or biocompatible materials.

[0095] The tip (3’) of the above said gas / fluid intake / delivery tube (3) can be in various forms and shapes that are atraumatic to avoid tissue damage or injury to the patients. The tip of the leak locator could be one or combination of the following: flat tip, round tip, corn shaped tip, padded round tip, possibly with expandable or contractable mechanism. In general, a smaller tip allows for precise locating the location of the organ wall defect, whereas a wider tip has lower spatial accuracy of the precise location but has the advantage of faster location of the portion of the organ that contains the wall defect. However, the size of the tip of the tube / probe (3) could be limited by the diameter of the trocar (9) used, which is in general between 5mm to 15 mm.

[0096] Means (16) to control the entry gas flow through the first intake / delivery line (3) are preferably also present, such as for example an on / off valve incorporated into the handheld body / housing (2) and manually operable by the user.

[0097] As indicated before, the above measurement unit (4), more precisely the gas outlet of the measurement unit, is connected to a second gas delivery tube (6), which is connected to ideally a separate trocar (9) already placed and inserted into the patient’s body cavity (BC) during the surgery. This creates a complete / circular gas flow passageway between the patient cavity and the leak locator system (1).

[0098] In particular, this second gas delivery tube (6) serves as an equalization line to equalize the pressure and flow differences between the influx of gas entering into the first gas delivery tube (3) and the pressure of the gas existing in the measurement unit (4). By equalizing the pressure and flow differences between the first gas / fluid delivery line and the body cavity of the patients, the leak localization accuracy is improved.

[0099] Instead of being connected to a second trocar or entering the patient’s body cavity through it, the second gas delivery tube / line (or equalization line or loop line or back gas line) may enter the patient’s body cavity through the same trocar as the one used by the first gas delivery line, said second gas delivery line being arranged along and next to the inserted fluid delivery tube of said first gas delivery line and ending a bit short of the tip of said tube.

[0100] For example, if an abrupt external pressure is applied to the body cavity of the patient during the leak localization, this will create a large pressure / flow fluctuation and disturbance and could disturb the on-going leak localization. The sudden change of the pressure / flow in the body cavity can be minimized or cancelled out, via the connection of the second gas / fluid delivery tube to the outlet of the measurement device and the body cavity.

[0101] The above first and second gas / fluid delivery tubes (3 and 6) can each be connected to at least one fluid filter for the removal of liquid fluid or viruses, airborne contaminants, microorganisms, pathogens, or other potentially contaminants that are circulating between the hardware and the patient to ensure patient safety. The choice of filter could be one or a combination of the hydrophobic filters, sterilizing filters, in-line filters, or other filters that cover these filtering properties.

[0102] As shown in figures 4 and 5, the measurement unit (4) can be housed in a separate housing (2’), independent of the leak detection system unit housing (7). The handheld leak locator system housing (2) is connected directly to a connector on the measurement unit housing (2’) via the first gas / fluid delivery tube (3); said connector is connected directly, or indirectly to the gas inlet of the measurement device unit itself (4); and the second gas / fluid delivery tube (6) (equalization line) is connected to the outlet of the measurement unit housing (2’), and the body cavity of the patient. The measurement unit housing (2’) is connected to the “leak detection system” unit, at least vie a data transmission line (13). In a further variation, the measurement unit housing (2’) contains all its electronic components and can be operated independently of the leak detection system, as an autonomous and standalone device.

[0103] As shown in figures 6 and 7, the measurement unit (4) of the leak locator system can be housed within the leak detection system unit (7), hence the two gas / fluid delivery tubes (3 and 6) are connected to said leak detection unit (7) via two connectors located on the external of the leak detection unit housing.

[0104] As shown in figures 8 and 9, the handheld leak locator body / housing (2) can contain all the electronic components (measurement unit, with storage, micro-controller, power supply, display, sensory outputs... etc), as well as the control means for the gas flow and the user interface, can have direct / indirect connection to the front and back gas delivery tubes and can be operated by the surgeon as it is. The gas delivery tube (3) is connected to the body cavity of the patient, preferably via a trocar. In a further variation, the measurement unit (4) has a separate signal transfer means connection to the computation unit of the leak detection system (7), where measurements information from the leak locator system (1) and the measurements information from the leak detection Unit are further processed to output the leak localization results in realtime.

[0105] In any of the previous embodiments, when the leak locator system (1) is connected to a leak detection system (7), for example the leak detection system of US11,357,932 or W02021 / 123012, the following may apply:

[0106] During the leak localization, the central computational unit of the leak detection system (7), such as the “leak detection system”, receives continuously a series of measurement data from the abdomen gas injection unit (i.e. gas flow, target set pressure, actual pressure time, temperature... etc) , the organ gas injection unit (i.e. gas flow, target set pressure, actual pressure, time, temperature., etc), the abdomen gas sensing unit (i.e. gas flow, abdomen pressure, time, test gas concentration... etc), together with the information from the measurement unit of the leak locator system (1), for example, any one of those: gas flow, pressure, test gas concentration, temperature...etc. At the start of the leak localization, the user inserts the tube / probe (3) into the body cavity of the patient via the trocar channel that is already in place in the patient, the user can direct the tip (3’) of the probe / tube (3) around the suture / staple line or other organ surface to verify the integrity of the organ closure and to locate the organ wall defect. Real-time measurement and signal processing are handled by the central processing unit of the leak detection system (7)., and real-time output signals are generated by the central processing unit when the leak locator system (1) detected signals (measurement data) has met certain pre-set measurement criteria.

[0107] The pre-set measurements criteria could be any one of the following:

[0108] - when the leak locator system measurement data is above a pre-set threshold (i.e. detect flow signal > O.OlL / min or detect pressure signal > 0.01 mmHg);

[0109] - when the leak locator system measurement data is above a pre-set value compared to the measurement data from the abdomen gas sensing unit (i.e. detect flow signal > O.OlL / min or detect pressure signal > 0.01 mmHg compared to the abdomen gas sensing unit).

[0110] When the tip (3’) is away from any organ wall defect, the gas property detected around the tip should be identical or similar to that of the detection from the abdomen gas sensing unit (homogeneity of gas flow assumption), the computational unit compute the differences, and when such differences fall below pre-defined values, the computational unit produces no additional sensory output signals to indicate the proximity of the leak location.

[0111] When the tip (3’) is placed close to or at the organ wall defect, the increased gas property change at the tip of the leak locator is recorded by the leak locator measurement device, and such measurement data are communicated to the central computational unit; when the local gas property change from the leak locator system measurement unit (4) is greater than the gas property recorded by the abdomen gas sensing unit, and that such differences are greater than the pre-set values, the computational unit generates in real-time or close to real-time a sensory signal that is output to the user via the user interface of the leak detection system (7) , and / or via the speaker of the system to signal that the “sampling” location of the tip is close to the organ wall defect.

[0112] According to an exemplary embodiment, the system (1) according to the invention (also called leak locator system in the present description) may advantageously comprise the following parts / elements / components :

[0113] - Handheld body (2) for handling and moving around the intake tube (3);

[0114] - Measurement unit (4);

[0115] - Rigid / semi rigid / soft elongate probe / tube (3) for gas exchange / intake, the tube can be inserted into the patients via a surgical trocar (9) or other surgical entry point;

[0116] - Atraumatic tip (3’) at the outlet of the gas intake delivery tube (the end that touches the patient) for precise localization; - Gas intake / delivery line comprising the probe / tube (3) and which connects to a measurement entry means that allow gas flow from the patient body cavity into the measurement unit (4);

[0117] - Gas back / return delivery line (6) with a tubing which connects the outlet of the gas measurement unit and the trocar of the patient body cavity to allow gas exchange between the gas measurement unit and the body cavity (return line).

[0118] The measurement unit (4) may comprise:

[0119] - at least one measurement sensor or a combination of measurement sensors (5) that measure the gas property (such as flow, pressure, gas concentration, temperature... etc);

[0120] - data storage capacity (11);

[0121] - computational signal processing and control capacity means (5’) (such as a microcontroller)

[0122] - sensory output / feedback means (5”) (i.e. display screens; light source, speakers... etc);

[0123] - power supply means (10);

[0124] - fluid filters adjacent to the tube connection between the measurement units (optional);

[0125] - one way gas valve (16) that allows and ensures a gas flow from the leak locator tip end to the gas measurement unit (optional);

[0126] - on / off control of the device (buttons, switch... etc-not shown);

[0127] - on / off flow control valve (16) to block flow through the gas reaching the leak locator measurement unit (optional).

[0128] When the measurement unit (4) is integrated in the module or central unit (7’) of the leak detection system (7), as shown in figure 6 and 7, its computational means (5’), memory / storage means (11), interface means (12) and / or power supply means (10), may advantageously be shared with the similar means of make use of the leak detection system (7), i.e. said unit (4) may use the means available within said system (7).

[0129] Similar to known leak detection methods and systems, the LeakQuest system, or a similar leak detection system, associated with the leak locator system (1), controls and manages the intralumenal pressure and the intra-cavitary pressures of the patient during the leak localization, so that the intralumenal pressure is always greater than the cavitary pressure at known values to facilitate gas flow from the organ wall defect. The target cavitary pressure is pre-set by the system. The target intralumenal pressure is pre-set by the system.

[0130] Alternatively, such pressure conditions could be achieved by other means, to allow for precise leak localization with the present invention. The corresponding target pressures are done via at least one pressure and flow regulation control of the abdomen injection (by system control, or manual control), and / or via at least one pressure and flow regulation control of the test organ injection (by system control, or manual control)

[0131] In one possible embodiment, the leak locator system (1) can also be combined with a vision device - such as standard laparoscopic camera (14) - hence the leak localization will be complemented with visual images of the target organ area (see figure 1). Different display modalities of the camera are possible to display perfusion-based imaging (Fluorescence imaging, hyperspectral imaging, laser- speckle contrast imaging, or imaging that are derived or combined with the above imaging principles).

[0132] As shown in figures 13A and 13B, the design of the tip (3’) of the probe (3) different shapes, forms, and / or internal diameters that could facilitate the localization, such has: the smaller the tip, the more precise the leak localization; Wider tips (possibly non-linear like : I shape) could capture wider localization information, but less precise leak localization.

[0133] The tube forming the gas intake probe (3) can have more than one channel (8), for example, as shown in figure 13. Based on the same principle as when only one channel is present, each elementary channel of four channels subdividing the interior of the tube could be connected to a different gas measurement sensor (i.e. 4 flow sensors, 4 pressure sensors, a combination of 2 flow sensors & 2 pressure sensors; as well as any combination of them). The measurement differences in each of the channels could be used to provide guidance information for the user to determine the direction to where the leak locator tip (3’) should be displaced, and so direct oneself closer along the direction where it has the highest measurement (see displacement direction shown on figure 13).

[0134] Of course, the invention is not limited to the embodiments described and represented in the accompanying drawings. Modifications remain possible, particularly from the viewpoint of the composition of the various elements or by substitution of technical equivalents without thereby exceeding the field of protection of the invention.

Claims

CLAIMS1. System (1) for locating an incomplete organ closure, an organ (HO) wall defect or the origin of an anastomotic / suture line leak during or after surgery, in a positive pressurized body cavity (BC), i.e. with a substantially extended body cavity and organ lumen insufflation, wherein said system (1) mainly comprises i) a handheld body or part or housing (2) which is connected, preferably mechanically and fluidly, to a gas intake or delivery line (3), preferably a rigid or semi-rigid long hollow probe, which forms a front gas delivery tube allowing gas to flow through it from its free tip (3’) and is intended to be inserted into the body cavity and being moved around inside it, ii) a measurement unit or means (4) comprising at least one sensor means (5) able to measure continuously at least one gas property, such as for example gas flow with a gas flow sensor, gas concentration with a gas concentration sensor and / or gas pressure with agas pressure sensor, or a combination of at least two such properties / sensors, and which preferably also comprises, or is associated or working with, at least some computational means (5’) and / or advantageously sensory feedback means (5”), and iii) a back gas line or second gas delivery tube (6) which connects the exit of the measurement unit (4) to the body cavity and acts as a gas pressure and / or flow equalization line, the system (1) thus providing a continuous gas flow loop between the body cavity and the measurement unit (4), with said back line allowing advantageously equalization of the gas pressure / flow between the inlet and the outlet of said measurement unit (4).

2. System according to claim 1, wherein it consists of a standalone and self- sufficient device, with autonomous operation.

3. System according to claim 1, wherein it is associated with, and preferably cooperating with, a gas-based leak detection system (7), for example a system for automatically detecting a clinically relevant leak and / or inadequate closure following a medical procedure, in an at least partially hollow organ or mutually fluidly connected hollow organs, as a separate yet connected device, or as a partly integrated device, for example for its measurement and / or computational means (4, 5’), which are possibly shared with said system (7).

4. System according to anyone of claims 1 to 3, wherein the measurement unit or means (4) are fitted, embedded or mounted in the hollow handheld body or part or housing (2), possibly together with computational means (5’) and / or sensory feedback means (5”).

5. System according to anyone of claims 1 or 3, wherein the measurement unit or means (4), possibly together with computational means (5’) and / or sensory feedback means (5”), are integrated, contained in or part of the central unit or module (7’) of a gas-based leakdetection system (7), for example a system for automatically detecting a clinically relevant leak and / or inadequate closure following a medical procedure, in an at least partially hollow organ or mutually fluidly connected hollow organs.

6. System according to anyone of claims 1 to 3, wherein the measurement unit or means (4), possibly together with computational means (5’) and / or sensory feedback means (5”), are contained in a specific or dedicated housing (2’), separate and distinct from the handheld body or part (2).

7. System according to anyone of claims 1 to 6, wherein the tube forming the gas intake probe (3) comprises a single channel (8) leading to the opening at the free end tip (3’) having an atraumatic shape.

8. System according to anyone of claims 1 to 6, wherein the tube forming the gas intake probe (3) comprises at least two separate channels (8) leading to the opening at the free end tip (3’) having an atraumatic shape.

9. System according to claim 8, wherein the tube forming the gas intake probe (3) comprises four channels (8) dividing said tube internally along its length, each channel being connected to a different sensor means (5).

10. Method for locating a leak in an organ, such as an incomplete organ closure, an organ wall defect or the origin of a anastomotic / suture line leak, during or after surgery, in a positive pressurized body cavity, i.e. with a substantially extended body cavity and organ lumen insufflation, said method mainly consisting in providing a system (1) according to anyone of claims 1 to 9, and using said system (1) to locate leaks by inserting the rigid or semi-rigid long hollow probe of the gas intake or delivery line (3) into the body or abdominal cavity (BC) containing the concerned organ (HO), moving said probe around in the cavity and along the organ wall, and exploiting the measurement signal delivered by said system (1), either directly or as a sensory feedback signal to locate a leak.

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