WO2005096959A1

WO2005096959A1 - Apparatus and method for determining suture integrity

Info

Publication number: WO2005096959A1
Application number: PCT/GB2005/000795
Authority: WO
Inventors: James Hewitt; Gareth Thomson
Original assignee: The University Of Dundee
Priority date: 2004-04-07
Filing date: 2005-03-03
Publication date: 2005-10-20
Also published as: GB0620670D0; GB0407857D0; GB2429165A

Abstract

An apparatus and method for determining suture integrity and in particular for determining the presence of leaks in an area where tissue has been joined. A clamp (7, 9) is used to press together tissue to form a substantially gas-tight seal around the area of tissue that has been joined by suture (3) such that the clamp and joined tissue form an enclosed space. A gas source (1) that can emit a detectable gas is placed within the enclosed space and a gas detector (15) is used to detect any gas that escapes from the enclosed space where the sutures have joined the tissue.

Description

Apparatus and Method for Determining Suture Integrity

The present invention relates to an apparatus and method for determining suture integrity and in particular for determining the presence of leaks in an area where tissue has been joined.

When a cancer or other disease is identified, often the only option is to remove the affected tissue. In practice, this will mean cutting through and remoΛ/ing a section of the affected area of tissue. The rema-ining healthy tissue will then be rejoined using staples or sutures. This approach is adopted in the surgical treatment of many types of cancers, for example, cancer of the colon, bladder and small intestine and ot? -er diseases.

It is extremely important to ensure the integrity of this join because where leakage from the join occurs, material can enter the area around the join and can cause infection. In the case of colon cancer, leakage from the join can cause faecal material to leak into the area around the colon and can cause the potentially fatal disease peritonitis .

In addition, detection of leaks post-operatively will occur when the patient complains of feeling unwell and will, in most cases, require additional surgery to repair the leak. Clearly this can have serious consequences for the patient and is expensive in terms of operating time and because less serious operations will have to be rescheduled to accommodate the required emergency surgery. In addition, where a leak has occurred and been corrected at a later stage, the longer term prognosis for the patient is significantly worse than if no leak had occurred. In the case of bowel surgery, leakage rates can be as high as 8% for anterior colon surgery, and 4% for surgery on the remainder of the colon.

A number of techniques have been developed to check the integrity of the joined tissue. For example, after suturing of the bowel during an operation to remove a cancerous lesion a leakage can be identified by using the following technique. Placing clamps across the bowel, botri above and below the suture point, then gently but firmly pressing the bowel with the fingers or a squeezing instrument and conducting a visual inspection of the joined tissue to determine whether any leakage of the bowel contents has occurred from the position of the tissue join. However, this approach specifically encourages leakage from the part of the bowel in question and relies on the surgeon being able to visually identify any leaks. In anot?tιer example saline solution is introduced into the open abdomen, then gas under low pressure is introduced into the rectum via the anus . Suture leakage is evidenced by the bubbling of gas through the saline solution from the suture stitching.

In anothier approach, the rectum is clamped above the suture and saline or methylene blue is introduced through the anus . The fluid is gravity fed from an elevated reservoir and the pressure of the liquid is monitored using a manometer. Leaks are found by checking for fluid seeping through the suture .

It is an object of the present invention to provide an apparatus to improve the detection of leaks in tissue.

In accordance with the first aspect of the present invention there is provided an apparatus for determining the presence of leaks in an area where tissue has been joined, the apparatus comprising: clamping means for pressing together tissue to form a substantially gas-tight seal around the area of the joined tissue, the clamping means and joined tissue forming an enclosed space; a gas source for emitting a detectable gas from within the enclosed space; and a gas detection means capable of detecting gas passing through the joined tissue.

Prefera??bly, the present invention is further provided with an enclosure having a gas-tight body shaped to extend around the area of joined tissue and having at least one conduit extending from the gas-tight body. Preferably, the enclosure is removably connectable to the clamping means.

Preferably, at least one conduit comprises a gas outlet conduit .

Preferably, at least one conduit comprises a gas inlet conduit and a gas outlet conduit, to allow a carrier gas to transport the detectable gas towards the gas detection means.

Optionally, the enclosure comprises a rigid material .

Optionally, the enclosure comprises a non-rigid material.

Optionally, the enclosure is constructed from a sheet of non-rigid material, the opposite ends of the sheet being mutually connectable.

Preferably, the clamping means is provided with coupling means to allow connection with the enclosure.

Preferably, the clamping means is provided by a constricting clamp.

More preferably, the constricting clamp is provided by a draw-string contained within a channel such that the length of the channel can be reduced when the draw-string is pulled.

Preferably the clamping means is made from non-rigid material . Preferably, the gas source comprises a brea_kable capsule.

Preferably, the gas source comprises a soluble capsule .

Preferably, the breakable capsule is made ffrom a biodegradable material .

Preferably, the biodegradable material is gjelatine.

Preferably, the gas source is provided by ait least two chemical reactants which react to provide the gas source .

Optionally, the chemical reactants are contained within said capsule arid react to provide the detectable gas when the capsule is broken.

Preferably, the detectable gas is a non-reactive gas.

Preferably, the detectable gas is carbon dioxide , helium or nitrogen .

Preferably, the gas detection means is adapted to detect a gas emitted from the gas source .

More preferably, the gas detection means is capable of detecting trace quantities of the detectable gas .

Preferably, the gas detection means is provided with a semi-conductor gas detector.

Optionally, the gas detection means is pro"vided with an optical gas detector. Optionally, the optical gas detector is a laser spectroscopy gas detector.

More preferably, the laser spectroscopy gas detector is provided with a laser beam that can be modulated to detect the quantity of the detectable gas.

Preferably, the gas detection means is provided with means for releasing a carrier gas into the enclosure.

Preferably, the gas detection means is provided with pressure control means for controlling the pressure of the carrier gas.

Preferably, the gas detection means is provided with gas input means for introducing ancl removing from the enclosure a carrier gas.

Preferably, the carrier gas is chemically different from the detectable gas.

More preferably, the carrier gas is carbon dioxide, helium or nitrogen.

Preferably, the enclosure is provided with an actuator for releasing the detectable gas.

More preferably, the actuator is capable of breaking the breakable capsule.

Preferably, the clamping means is provided with coupling means to allow connection with the enclosure. In accordance with a second aspect of the present invention there is provided a method for determining the presence of leaks in an area where tissue has been joined, the method comprising the steps of: clamping together tissue to form a substantially gas- tight seal around the area of the joined tissue, to form an enclosed space; emitting a detectable gas from a gas source from within the enclosed space; and detecting the detectable gas passing through the joined tissue.

Preferably, the detectable gas is emitted into an enclosure having a gas-tight body shaped to extend around the area of joined tissue and having at least one conduit extending from the gas-tight body.

Preferably, the method further comprises the step of removably connecting the enclosure to the clamping means prior to emission of the detectable gas.

Preferably, a carrier gas is introduced into the enclosure via a gas inlet conduit and is used to transport the detectable gas by means of a gas outlet conduit towards the gas detection means .

Optionally, the enclosure is constructed from a rigid material.

Optionally, the enclosure is constructed from a non-rigid material. Preferat>ly, the clamping means is connectable to the enclosure.

Preferably, the step of clamping together tissue is undertakien by a constricting clamp placed around the tissue.

Preferably, a breakable capsule is used to emit a detectable gas from a gas source from within the enclosed space.

Preferably, a soluble capsule is used to emit a detectable gas from a gas source from within the enclosed space.

Preferably, a biodegradable capsule is used to emit a detectable gas from a gas source from within the enclosed space.

Preferably, the gas source is provided by at least two chemical reactants which react to provide the gas source.

Optionally, the chemical reactants are contained within said capsule and react to provide the detectable gas when the capsule is broken.

Preferably, the detectable gas is a non-reactive gas.

Preferably, the detectable gas is carbon dioxide, helium or nitrogen.

Preferably, the pressure of the carrier gas is controllable. The present invention will now be described by way of example only with reference to the accompanying drawings in which :

Figure 1 shows a length of colon joined by sutures;

Figure 2 illustrates a length of colon which is clamped and to which a gas source is to be added;

Figure 3 illustrates an embodiment of the present invention in which a detector is positioned adjacent to tlie joined tissue;

Figure 4 shows an enclosure of the present invention w iich extends around the joined tissue;

Figure 5 shows an enclosure of the present invention formed in two halves, the first halve being fixedly attached to a clamp;

Figure 6 shows an embodiment of the present invention having an enclosure gas detection means and a gas carrier s ource ;

F igure 7 shows an enclosure of the present invention in wliich the enclosure has a non-rigid structure ; and

F igure 8a is a perspective view of a further embodiment o f the present invention comprising a sheet of flexible material and Figure 8b is a further perspective view of tlie embodiment of Figure 8a in use on a section of colon . With reference to Figure 1, this shows a section of colon 1 and the position of the joined tissue 3, which in this case has been sutured. The integrity of the sutures or other means for joining the tissue is of crucial importance and leakage from this join can have potentially fatal consequences for the patient.

Figure 2 shows a section of colon 1 and a pair of clamps 7 and 9 located at either side of a section of colon which is in the process of being joined. An opening in the colon is apparent at reference numeral 5. In addition, a line of suture thread 13 is shown in this diagram.

The gas source or capsule 11 as used in the present invention is also shown in this figure. The capsule 11 is constructed from a brea? able material such as gelatine in this example so that a minimum amount of force is required in order to break the capsule and to release he gas. The capsule is constructed such that it remains intact prior to its introduction through the opening 5 in the section of colon. Once the capsule 5 has been introduced into the section of colon, the process of suturing together the colon tissue beside the opening can be completed.

Figure 3 shows an embodiment of the present invention having a detector 15 in proximity to the joined tissue 3 -. The joined tissue is clamped at either end using clamps 1 and 9 in order to form an enclosed space which is substantially gas-tight. Once the apparatus is ready four use, the capsule 11 can be broken in order to release he detectable gas. If there is a leakage in the suture joint, gas will pass through the leak and be detected by the detector. The capsule 11 may be broken simply by manual pressure or through the use of a minimum access surgery probe or other similar instrument.

In this example, the detector 15 is constructed from a semi-conductor sensor which detects gas passing over an exposed semi-conductor element. The gas is detected by means of a change in the electrical properties in the semi-conductor elements. The detector may be incorporated into an existing surgical instrument.

Advantageously, the arrangement provided in this embodiment will allow the user to identify the location of the leak.

Figure 4 shows an embodiment of the invention with a chamber 17 which has rigid walls, a gas inlet 19 and a gas outlet 21. The chaiabier is constructed in two halves, each of which are separa-tely connectable to the clamps 7 and 9 to provide the complete enclosure. In this example, a simple mechanical coupling is used to connect the two halves of the cbi-amber 17 to the clamps 7 and 9.

In use, the position at which the tissue is to be joined is identified and suturing of the tissue is commenced to a point where an opening" is left in the colon (as shown in figure 2) . At this point, the clamps 7 and 9 are introduced and connected at either side of the suture point. These clamps 7 and 9 are secured in position to provide a substantially gas tight seal at either side of the suture point. Once this has been complete, the capsule 11 is introduced into the section of colon and the suturing 3 is completed. Thereafter, the chamber 17 is connected to the clamps.

Figure 5 shows an alternative arrangement in which the lower part 17a of the enclosure is fixedly connected to the clamps 27 and 29. In this example, the upper section of the chamber 17b is connectable once the capsule has been added and the suturing has been completed.

Figure 6, shows an embodiment of the present invention, with a chamber 17 similar to that shown in Figure 4. Figure 6 also shows the gas detection means 15 along with a gas carrier source 31. The gas carrier source 31 is attached to a valve 33 which is provided with pressure sensing means (not sho~wn) to allow a user to control the pressure of carrier gas and the flow of carrier gas through the chamber 17.

In use, the carrier gas is passed to the chamber via carrier gas conduit 37 and enters the chamber 17 at gas inlet 19. A gas outlet 21 is provided on the chamber and this is coupled to a detector conduit 39. The detector 15 is also provided with an exhaust port 35 for the removal of carrier gas and any detectable gas after use.

In use, a carrier gas is passed from its source 31 through conduit 37 ancl into the chamber 17. The carrier gas is used to provide a flow of gas through the chamber in order to help remove any detectable gas which has leaked from the joineci tissue 3. In this example, the detector 15 uses laser spectroscopy to identify the detectable gas. This technique uses a low powered laser beam which is partly absorbable by the gas. The level of light absorption being a function of the gas type and the wavelength of the laser light. In addition, modulation of the laser beam allows detection of the presence and the levels of the detectable gas. The detectable gas and the carrier gas therefore have different chemical constituents to allow tb-em to be distinguishable by the detectors whether tliey are laser detectors or semiconductor detectors.

Figure 7 shows a further embodiment of the present invention in which the chamber 41 is constructed from a non-rigid material .

Advantageously, the use of a non-rigid chamber allows the capsule 11 to be broken open from outside the chamber 41 either manually or by using an instrument. As with other examples of the present invention, the chamber is connected to a detection means and a carrier gas can be used to assist with the throughput of gas in the system.

The embodiment of the present invention in Figures 8a and 8b shows a layer of flexible material or membrane 42 having a pair of nozzles 46 attached to the circumference of apertures in the membrane 42. This embodiment is further provided with attachment means 44, 48 which allow the ends of the device to be connected together. In this example, the flap 44 can be folded under the opposite end of the device 48. Draw strings 43 are provided in channels 50. Figure 8b shows this embodiment of the present invention in use. As can be seen, the flexible material or membrane 42 has been wra-pped around the section of colon 1 and the flap 44 ffolded under opposite end 48. The draw strings, when pulled, act as a clamp that constricts around the colon. -This happened by reducing the length of the channels that are enclosing the draw-strings thereby reducing the length of the channels.

As with previous examples a gas sourrce is placed in the section of colon prior to application of the device and the nozzles 46 may be connected to a gas detector and a carrier gas source. As this embodiment of the invention uses a non-rigid clamp, it may be particularly useful in keyhole surgery.

In addition, embodiments of the present invention may be provided with an actuation means situated inside the chamber which can impinge upon the capsule and cause it to break open, thereby releasing the gas.

The present invention has the following practical advantages over the prior art that -arise from being able to identify leaks in joined tissue.

• Patients will have a lower risk of complications resulting from surgery - such as peritonitis • Surgeons will have greater confidence in completing operations as they will be able to easily check the integrity of the sutures. • There will be a reduction in the number of emergency operations required to repair tissue and close leaks in the tissue. Consequently, the cost of care for each patient will be reduced. The above embodiments describe the use of the invention for the detection of leaks in a suture joint in surgery for treatment of colon cancer. In addition, it is envisaged that the present invention could be used for the detection of leaks in a suture joint in other surgical procedures including, but not limited to, surgery for cancer of the colon, bladder ancl small intestine or other diseases where surgery is required.

Improvements and modifications may be incorporated herein without deviating from the scope of the invention.

Claims

1. An apparatus for determining the presence o f leaks in an area where tissue has been joined, the apparatus comprising: clamping means for pressing together tissue to orm a substantially gas-tight seal around the area of the joined tissue, the clamping means and joined tissue forming an enclosed space; a gas source for emitting a detectable gas from within the enclosed space; and a gas detection means capable of detecting gas passing through the joined tissue.

2. An apparatus as claimed in claim 1, further- provided with an enclosure having a gas-tight body shapecl to extend around the area of joined tissue and having at least one conduit extending from the gas-tight body.

3. An apparatus as claimed in claim 2 wherein, the enclosure is removably connectable to the clamping means.

4. An apparatus as claimed in claim 2 or claim 3 wherein the at least one conduit comprises a gas outlet conduit.

5. An apparatus as claimed in claim 2 or claim 3 wherein the at least one conduit comprises a gas inlet conduit and a gas outlet conduit, to allow a cairrier gas to transport the detectable gas towards the gas detection means.

6. An apparatus as claimed in any of c lai s 2 to 5 wherein, the enclosure comprises a rigid- material.

7. An apparatus as claimed in any of claims 2 to 5 wherein, the enclosure comprises a non-r^~igid material.

8. An apparatus as claimed in claim 7 wherein, the enclosure is constructed from a sheet off non-rigid material, the opposite ends of the sheet being mutually connectable.

9. An apparatus as claimed in any preceding claim wherein, the clamping means is provided with coupling means to allow connection with the enclosure.

10. An apparatus as claimed in any preceding claim wherein, the clamping means is provided by a constricting clamp.

11. An apparatus as claimed in claim lO wherein, the constricting clamp is provided by a draw-string contained within a channel such that the length of: the channel can be reduced when the draw-string is pulled.

12. An apparatus as claimed in any preceding claim wherein, the clamping means is made from non-rigid material.

13. An apparatus as claimed in any preceding claim wherein, the gas source comprises a breakable capsule.

14. An apparatus as claimed in any preceding claim wherein, the gas source comprises a solxuble capsule.

15. An apparatus as claimed in claim 13 wfherein, the breakable capsule is made from a biodegradable material.

16. An apparatus as claimed in claim 15 wherein, the biodegradable material is gelatine.

17. An apparatus as claimed in any preceding claim wherein, the gas source is provided by at least two chemical reactants which react to provide the gas source.

18. An apparatus as claimed in claim 17 wherein, the chemical reactants are contained within said capsule and react to provide the detectable gas when the capsule is broken.

19. An apparatus as claimed in any preceding claim wherein, the detectable gas is a non-reactive gas.

20. An apparatus as claimed in any preceding claim wherein, the detectable gas is carbon dioxide, helium or nitrogen.

21. An apparatus as claimed in any preceding claim wherein, the gas detection means is adapted! to detect a gas emitted from the gas source.

22. An apparatus as claimed in any preceding claim wherein, the gas detection means is capable of detecting trace quantities of the detectable gas.

23. An apparatus as claimed in any preceding claim wherein, the gas detection means is provided with a semi- conductor gas detector.

24. An apparatus as claimed in any preceding claim wherein, the gas detection means is provided with an optical gas detector.

25. An apparatus as claimed in claim 24 wherein, the optical gas detector is a laser spectroscopy gas detector.

26. An apparatus as claimed in claim 25 wherein, the laser spectroscopy gas detector is provided! with a laser beam that can be modulated to detect the quαantity of the detectable gas.

27. An apparatus as claimed in any preceding claim, the gas detection means is provided with means for releasing a carrier gas into the enclosure.

28. An apparatus as claimed in any preceding claim wherein, the gas detection means is provided with pressure control means for controlling the pressure of the carrier gas.

29. An apparatus as claimed in any preceding claim wherein, the gas detection means is provided with gas input means for introducing and removing from the enclosure a carrier gas.

30. An apparatus as claimed in claim 29 wherein, the carrier gas is chemically different from the detectable gas .

31. An apparatus as claimed in claim 29 or 30 wherein, the carrier gas is carbon dioxide, helium or nitrogen.

32. An apparatus as claimed in any of claims 2 to 31 wherein, the enclosure is provided with an actuator for releasing the detectable gas.

33. An apparatus as claimed in claim 32 wherein, the actuator is capable of breaking the breakable capsule.

34. An apparatus as claimed in any preceding claim wherein, the clamping means is provided with coupling means to allow connection with the enclosure.

35. A method for determining the presence of leaks in an area where tissue has been joined, the method comprising the steps of: clamping together tissue to form a substantially gas- tight seal around the area of the joined tissue, to form an enclosed space; emitting a detectable gas from a gas source from within the enclosed space; and detecting the detectable gas passing th-rough the joined tissue.

36. A method as claimed in claim 35 wh-erein, the detectable gas is emitted into an enclosure having a gas- tight body shaped to extend around the area of joined tissue and having at least one conduit extending from the gas-tight body.

37. A method as claimed in claim 35 or claim 36 wherein, the method further comprises the step of removably connecting the enclosure to the clamping means prior to emission of the detectable gas.

38. A method as claimed in claims 35 to 37 wherein, a carrier gas is introduced into the enclosure via a gas inlet conduit and is used to transport the detectable gas by means of a gas outlet conduit towards the gas detection means .

39. A method as claimed in claims 35 to 38 wherein, the step of clamping together tissue is undertaken by a constricting clamp placed around the tiss ie.

40. A method as claimed in claims 35 to 39 wherein, a breakable capsule is used to emit a detectable gas from a gas source from within the enclosed space .

41. A method as claimed in claims 35 to 39 wherein, a soluble capsule is used to emit a detectaffole gas from a gas source from within the enclosed space .

42. A method as claimed in claims 35 to 39 wherein, the gas source is provided by at least two chemical reactants which react to provide the gas source.

43. A method as claimed in claim 42 wherein, the chemical reactants are contained within said capsule and react to provide the detectable gas wfhen the capsule is broken.