Abstract:
Air introduction device for anastomotic leak testing including an elastomeric body optimally configured for partial insertion into the rectum, occlusion of the anus and attachment to a commercially available insufflation bulb. The air introduction device may be dip molded in one piece to form a single use, disposable product. The body has a proximal portion insertable into an anus of a person to cause the anus to constrict around it and form a seal against the anal wall, a distal portion mating with the insufflation bulb to enable air to be directed therefrom into and through the body and an expanded portion which is larger than the proximal portion and interposed between the proximal portion and the distal portion. The expanded portion occludes the anus by engaging with the anal opening to limit insertion of the proximal portion into the anus and seal the body against the anal opening. Embodiments incorporating means to allow the insertion of an endoscope through the device for visual inspection of an anastomosis, and means to prevent over-inflation of the rectum are described.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a device for introducing air into the rectum of a patient during a surgical operation to remove the distal colon and part of the rectum in order to evaluate the integrity of an anastomosis, i.e., detect anastomotic leakage. The present invention also relates to methods for testing for anastomotic leakage and for visualization of a completed anastomosis.  
       BACKGROUND OF THE INVENTION  
       [0002]     Surgical operations to remove the distal colon and part of the rectum are common for illnesses such as neoplasia, diverticular disease and inflammatory bowel disease. When the continuity of the intestinal tract is to be preserved, the bowel must be reconnected by means of sutures, staples or a compression device. This connection is called an anastomosis.  
         [0003]     If there is a defect in the anastomosis, bowel content can leak out of the bowel and contaminate the normally sterile peritoneal cavity, causing peritonitis. Peritonitis (infection of the peritoneal cavity) can be lethal, and therefore measures must be taken during surgery to ensure that leaks in the anastomosis are not present. One such measure is to fill the pelvic portion of the abdominal cavity with saline or water to a level which immerses the completed anastomosis, then insufflate the rectum with air while occluding the bowel above the anastomosis. As the rectum distends, the pool of saline is observed for air bubbles which, if present, signal a defect in the anastomosis, i.e., a leak, which must then be repaired.  
         [0004]     One device currently used to insufflate air into the rectum is a proctoscope, i.e., a tubular instrument designed for looking into the rectum. The proctoscope has an insufflation bulb attached to it. With the lens gate of the proctoscope closed, air is introduced into the rectum by compressing the insufflation bulb.  
         [0005]     Use of a proctoscope for rectal insufflation to test for anastomotic leaks has advantages and disadvantages. The fact that proctoscopes are items usually stocked in an operating room is an advantage. Thus, an additional surgical instrument does not need be purchased or stocked in an operating room in order to test for anastomotic leaks. Moreover, it is advantageous that it is possible to visually inspect the anastomosis from inside the bowel using the proctoscope. This helps identify potentially harmful bleeding, which can then be stopped by suture ligation.  
         [0006]     On the other hand, a significant disadvantage of the use of a proctoscope results from the fact that a sterile proctoscope has to be contaminated to check for leaks and then repackaged and sterilized for future use. For example, if a proctoscope is used at the very start of surgery to examine a rectal tumor or cleanse the rectum, as is sometimes done, then it must either be kept in the operating room in a dirty state, or cleansed in a nearby utility room by a nurse, until such time as it is again needed to test the anastomosis. This not only clutters the operating room, but can potentially contaminate the operating room, and in any event, necessitates extra labor by a circulating nurse. The cost savings gained by using an instrument already in stock and accessible may be lost by the extra labor involved in maintaining the instrument in the operating room and repackaging and sterilizing the proctoscope after surgery.  
         [0007]     An additional disadvantage of using a proctoscope to insufflate the rectum is that the insufflated air tends to leak out through the anus around the proctoscope, which typically has an outer diameter of about 0.75 inches. It therefore requires some extra effort to distend the rectum to the desired amount to effectively test the anastomosis. It is also possible to over-distend the rectum with air insufflation and actually disrupt the anastomosis. It is not possible to accurately gauge the level of air pressure in the rectum because the proctoscope does not provide any mechanism to measure the air pressure in the rectum, and thus the air pressure can only be grossly evaluated by visual inspection of the distended bowel above the pool of saline, or by feeling the bowel.  
         [0008]     Yet another drawback of the use of a proctoscope is that although the proctoscope can be used to visually inspect the stapled anastomosis inside the bowel, the view obtained via a standard proctoscope is relatively poor, is not sufficiently keen to allow the surgeon to spot small anastomotic defects and usually requires the surgeon to crouch in an awkward position and spend some time to achieve a satisfactory inspection.  
         [0009]     Furthermore, after performing an anastomosis and prior to testing for leaks, some surgeons prefer to cleanse the rectum with an antiseptic before they force air into the rectum and potentially into the sterile peritoneal cavity should there be an anastomotic leak. If a proctoscope which was used earlier, e.g., to cleanse the rectum, is reused without being resterilized, then they may insufflate the rectum with particles of fecal debris or airborne bacteria that remain within the scope or within the insufflation bulb or tubing which carries air from the insufflation bulb to the proctoscope. Such fecal debris or airborne bacteria could contribute to the development of postoperative peritonitis or wound infection.  
         [0010]     Thus, there are significant drawbacks to the use of a standard proctoscope to insufflate air into the rectum and to inspect an anastomosis and it would be desirable to provide alternative means to insufflate the rectum and inspect the anastomosis which avoid these drawbacks.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0011]     It is an object of the present invention to provide a simple, inexpensive and disposable device to be used during surgery for insufflation of the rectum with air to test for anastomotic leakage.  
         [0012]     It is another object of the present invention to provide new methods for testing for anastomotic leaks using a novel air introduction device.  
         [0013]     It is still another object of the present invention to provide an anastomotic leak tester including a novel air introduction device which is easier to use than a proctoscope for the purpose of testing an anastomosis for leaks.  
         [0014]     It is yet another object of the present invention to provide an air introduction device for testing for anastomotic leaks which is safer to use than a standard proctoscope.  
         [0015]     Another object of the present invention is to provide an inexpensive anastomotic leak tester that can lead to cost savings and more efficient use of operating room time and personnel.  
         [0016]     Another object of the present invention is to provide a new anastomotic leak tester which provides a signal when there is sufficient air pressure in the rectum.  
         [0017]     Still another object of the present invention is to provide a new and improved anastomotic leak tester which enables improved visualization of the anastomosis from within the bowel.  
         [0018]     In order to achieve these objects and others, an air introduction device for use in anastomotic leak testing in accordance with the invention comprises an elastomeric tube, optimally configured for partial insertion into the rectum, occlusion of the anus and attachment to a commercially available pumping device such as an insufflation bulb. The air introduction device may be dip molded in one piece so that it would be simple and inexpensive to manufacture and ideal for a single use, disposable product.  
         [0019]     More specifically, the air introduction device for use in anastomotic leak testing comprises a unitary, elastomeric body defining an interior space and having a proximal portion adapted to be inserted into an anus of a person to cause the anus to constrict around it and thereby form a seal against an anal wall, a distal portion adapted to mate with a pumping device, such as an insufflation bulb, to enable air to be directed from the pumping device into and through the body and an expanded portion having a larger size than the proximal portion and interposed between the proximal portion and the distal portion. The expanded portion occludes the anus by being adapted to engage with an anal opening to limit insertion of the proximal portion into the anus and seal the elastomeric body against the anal opening.  
         [0020]     In one embodiment, the distal portion includes only a single arm, i.e., a single tubular segment defining a lumen adapted to receive the insufflation bulb. In this case, the distal portion has an outer diameter smaller than the outer diameter of the proximal portion.  
         [0021]     In another embodiment, the distal portion has two arms, one arm defining a lumen adapted to receive a connector of the insufflation bulb and the other arm defining a lumen through which a visualization device or endoscope such as a laparoscope may be inserted when the distal end is changed from a closed form to an open form. Thus, one arm serves as an insufflation arm and the other serves as an endoscopic port.  
         [0022]     Instead of or in addition to an arm providing an endoscopic port, an arm can be provided to retain a pressure relief valve for releasing air when a specific air pressure in the rectum is reached. This prevents over-inflation of the rectum. A signal mechanism can be associated with the valve to provide a signal when air is released via the valve, e.g., an extension coupled to the arm and including vibrating flaps which vibrate and produce an audible sound when air is released via the valve. Alternatively, the functions of a pressure relief valve and signal mechanism can be incorporated into a single element, whose flaps will separate and vibrate only when a critical air pressure within the rectum is reached.  
         [0023]     Another way to consider the air introduction device in accordance with the invention would be as a unitary body defining an interior space and having an insertion and sealing mechanism for enabling insertion of a part of the body into an anus of a person such that the anus constricts around the part and thereby seals the body against anal walls, an insertion-limiting mechanism for limiting insertion of the part of the body into the anus and occluding the opening of the anus, and a coupling mechanism for enabling coupling of the body to an insufflation bulb such that air is directable from the insufflation bulb through the coupling mechanism into the interior space in the elastomeric body. The insertion and sealing mechanism may be the proximal portion of the body discussed above. The insertion-limiting and anal occluding mechanism may be the expanded portion of the body discussed above. The coupling mechanism may be a lumen arranged on a distal portion of the body and adapted to receive a connector of the insufflation bulb.  
         [0024]     The distal portion can include, in addition to a lumen in an arm for receiving a connector of an insufflation bulb, an arm defining a lumen through which a visualization device or endoscope such as a laparoscope may be inserted and/or an arm having a pressure relief mechanism for releasing air when a specific air pressure in the rectum is reached, with or without a signal mechanism.  
         [0025]     An exemplifying method for anastomotic leak testing in accordance with the invention includes the steps of providing a unitary body defining an interior space and having a proximal portion, a distal portion and an expanded portion interposed between the proximal portion and the distal portion, coupling an insufflation bulb to the distal portion of the body, and inserting the proximal portion of the elastomeric body into the anus of a patient to cause the proximal portion to dilate the anus whereby the anus constricts around the proximal portion and a seal is formed between the proximal portion and the wall of the anus to prevent escape of air from the rectum, and the expanded portion presses against the opening of the anus also to prevent the escape of air from the rectum. The pelvis of the patient is filled with fluid, the insufflation bulb is repeatedly compressed to distend the rectum of the patient with air and a check for anastomotic leaks is performed based on the presence of air bubbles in the pelvic fluid once the rectum is sufficiently distended with air. The insufflation bulb may be detached from the body after checking for anastomotic leaks while the proximal portion of the body remains inserted in the anus thereby allowing air from the rectum to escape from the rectum and the rectum to deflate. The body is then removed from the anus.  
         [0026]     The body may include a second arm having a lumen through which a visualization device or endoscope such as a laparoscope may be inserted. Initially, the end of the second arm is closed but after the initial anastomotic leak check described above is performed, the body is removed from the anus and the closed end of the second arm is opened. An endoscope may then be inserted into the lumen so that the tip of the endoscope sits within a space of the elastomeric body. The proximal portion of the body is re-inserted into the anus and the insufflation bulb is again compressed to distend the rectum of the patient with air. The anastomosis is then visually inspected by advancing the tip of the endoscope from the space in the elastomeric body into the rectum until the anastomosis is viewable through the endoscope or on a video display to thereby enable the integrity of the anastomosis to be ascertained and to check for bleeding at the anastomosis. The endoscope is removed from the elastomeric body when the visual inspection is complete while the body is engaged with the anus and then the rectum is deflated and the body removed out of engagement with the anus.  
         [0027]     An air introduction device for anastomotic leak testing in accordance with the invention, and method for using the same, has several advantages over the prior art, notably the use of a standard proctoscope for the purpose of insufflating the rectum to test for anastomotic leakage. An anastomotic leak tester including the air introduction device is easier to use than a proctoscope because it is more compact and requires only one hand to operate, whereas a proctoscope is relatively unwieldy and requires two hands to use, one to position the proctoscope and the second to repetitively compress the insufflation bulb. The device in accordance with the invention is also easier to use than a proctoscope because it prevents air from escaping from the rectum around the device, resulting in fewer insufflation bulb compressions to achieve the same rectal distension.  
         [0028]     An anastomotic leak tester including the air introduction device in accordance with the invention is also safer to use than a standard proctoscope because the device is sterile until used to insufflate the rectum and therefore no potentially hazardous debris collects in the device nor is there a possibility of debris originating from the device contaminating the peritoneal cavity (as is the case when a contaminated proctoscope is used).  
         [0029]     The anastomotic leak tester is also designed to be an inexpensive alternative to a proctoscope and to be easier to open, use and dispose of than it would be to cleanse a proctoscope, transport it, repackage it and sterilize it again.  
         [0030]     One embodiment of the anastomotic leak tester also prevents the surgeon from inflating the rectum above a desired pressure by providing a pressure relief valve.  
         [0031]     Another embodiment provides a signal when a desired air pressure within the rectum is reached.  
         [0032]     Another embodiment of the anastomotic leak tester is designed for use in conjunction with a laparoscope or other image-obtaining device that can visualize the anastomosis from within the bowel to a degree of clarity which far surpasses the view that one can achieve with a rigid proctoscope. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0033]     The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals identify like elements.  
         [0034]      FIG. 1  is a perspective view of a first embodiment of an air introduction device for use in anastomotic leak testing in accordance with the invention.  
         [0035]      FIG. 2  is a cross-sectional view of the embodiment shown in  FIG. 1 .  
         [0036]      FIG. 3  is a perspective view of an insufflation bulb for use in combination with the air introduction device in accordance with the invention.  
         [0037]      FIG. 4  is a perspective view of the first embodiment of the air introduction device in accordance with the invention shown coupled to the insufflation bulb shown in  FIG. 3  to form an anastomotic leak tester in accordance with the invention.  
         [0038]      FIG. 5  is a diagram showing the use of the anastomotic leak tester of  FIG. 4  inserted into the anus of a patient for testing of an anastomosis.  
         [0039]      FIG. 6  is a perspective view of a second embodiment of an air introduction device for use in anastomotic leak testing in accordance with the invention.  
         [0040]      FIG. 7  is a cross-sectional view of the embodiment shown in  FIG. 6 .  
         [0041]      FIG. 8  is a perspective view of the second embodiment of the air introduction device in accordance with the invention shown coupled to the insufflation bulb shown in  FIG. 3  to form an anastomotic leak tester in accordance with the invention.  
         [0042]      FIG. 9  is a perspective view of the anastomotic leak tester of  FIG. 8  showing a laparoscope inserted through the endoscopic port.  
         [0043]      FIG. 10  is a diagram showing the use of the anastomotic leak tester of  FIG. 9  inserted into the anus of a patient for inspection of an anastomosis.  
         [0044]      FIG. 11  is a cross-sectional drawing of a third embodiment of an air introduction device in accordance with the invention.  
         [0045]      FIG. 12  is a cross-sectional drawing of a fourth embodiment of an air introduction device in accordance with the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0046]     Referring to the accompanying drawings wherein like reference numerals refer to the same or similar elements,  FIGS. 1 and 2  show a first embodiment of an air introduction device for anastomotic leak testing in accordance with the invention which is designated generally as  10 . The air introduction device  10  comprises a substantially tubular, unitary body  12  defining an interior space  12   a  and has a proximal segment or portion  14  and a distal segment or portion  16  separated from the proximal portion  14  by an expanded segment or portion  18 .  
         [0047]     The body  12  of the air introduction device  10  may be made of an elastomer compatible for contact with internal parts of the human body, namely the anal wall and anal opening as discussed below, and fabricated using a dip molding technique to obtain a soft, pliable form. Other plastic manufacturing methods can also be used.  
         [0048]     Proximal portion  14  has a substantially uniform inner and outer diameter with the exception that a tip  20  of the proximal portion  14  is rounded or tapered to aid insertion of proximal portion  14  into the anus of an anesthetized patient. The distal portion  16  has a substantially uniform inner and outer diameter smaller than those of the proximal portion  14 . Expanded portion  18  has an outer circumferential portion  18 a having the largest diameter of the entire body  12  and which is dimensioned to be larger than the opening of most human anuses when they are maximally dilated so that the body  12  can&#39;t be inserted into the anus farther than the outer circumferential portion  18   a . That is, the expanded portion  18  serves as insertion-limiting flange which serves to limit the amount of insertion of the proximal portion  14  of the body  12  into the anus. The expanded portion  18  includes two truncated conical surfaces  22   a ,  22   b , one surface  22   a  tapering from the outer circumferential portion  18   a  toward the rear edge of the proximal portion  14  and one surface  22   b  tapering from the outer circumferential portion  18   a  toward the front edge of the distal portion  16 .  
         [0049]     The air introduction device  10  is designed for use with a pumping device such as an insufflation bulb  24  shown in  FIG. 3 . The insufflation bulb  24  has a central tubular portion  24   a  defining an interior space receivable of air and is coupled to the distal portion  16  of the body  12  (see  FIG. 4 ). More specifically, the insufflation bulb  24  includes a connector  26  which is insertable into a lumen  28  defined by the distal portion  16  of the air introduction device  10 . The insufflation bulb  24  also includes a valve  30  at a proximal end  32  (housed within the connector  26  of the insufflation bulb  24  as shown in  FIG. 5 ) and a valve  34  at a distal end  36  (housed within the insufflation bulb  24 ). The valves  30 , 34  permit movement of air in one direction only, specifically in a direction from the distal end  36  to the proximal end  32 .  
         [0050]     A central portion  24   a  of the insufflation bulb  24  between the valves  30 , 34  is compressible and when compressed, forces air from a space  38  defined in the interior of the insufflation bulb  24  through the valve  30  at the proximal end  32  and through the connector  26  (and into the air introduction device  10  when coupled to the insufflation bulb  24 ). When the compressing force on the central portion  24   a  of the insufflation bulb  24  is released, air flows into the space  38  through the valve  34  at the distal end  36 . Upon the next compression of the central portion  24   a  of the insufflation bulb  24 , this air is then directed through the connector  26  into the air introduction device  10 . As such, a pumping action is obtained upon repeated compressions and releases of the central portion  24   a  of the insufflation bulb  24 .  
         [0051]     Referring now to  FIG. 5 , in one exemplifying use to test whether an anastomosis  48  is leak-proof, the insufflation bulb  24  is coupled to the air introduction device  10  by inserting connector  26  into the lumen  28  of the distal portion  16  of the air introduction device  10  to thereby form the anastomotic leak tester  50  shown in  FIG. 4 . The proximal portion  14  of the air introduction device  10  is then inserted into the anus  40  of an anesthetized patient (see  FIG. 5 ). The pelvis is filled with fluid and the bowel above the anastomosis is occluded with a clamp  49 . Repeatedly compressing the insufflation bulb  24  distends the rectum  42  with air. Air cannot escape from the anus  40  because the proximal portion  14  is dimensioned such that its walls dilate the anus  40  whereby the elastic anus constricts around the proximal portion  14  of the air introduction device  10  to form a seal between the walls of the proximal portion  14  and the walls of the anus  40 . Thus, air cannot pass between the outer wall of the air introduction device  10  and the wall of the anus  40 .  
         [0052]     Furthermore, as the rectum  42  is being insufflated by the repeated compression of the insufflation bulb  24 , the air introduction device  10  is pushed inward until the conical surface  22   a  of the expanded portion  18  presses against the anal verge or opening  44 , adding a further seal to prevent the escape of air from the rectum  42 . When the rectum  42  is sufficiently distended with air, and no air bubbles are seen in the pelvic fluid, it can be considered that the anastomosis  48  is air tight.  
         [0053]     The insufflation bulb  24  is then detached from the air introduction device  10  while the proximal portion  14  thereof remains in the anus  40 , which allows air from the rectum  42  to escape, and allows the rectum  42  to deflate. The air introduction device  10  is then removed out of engagement with the anus  40 .  
         [0054]     In one exemplifying embodiment, the outer diameter of the walls defining the proximal portion  14  is approximately 1.062 inches, which has been determined to be suitable to allow it to be inserted into the anal canal of an anesthetized patient with ease and at the same time prevent the escape of air from the rectum  42  by passing between the wall of the air introduction device  10  and wall of the anus  40 . The largest diameter of the expanded portion  18 , i.e., the outer circumferential portion  18   a , has an approximate outer diameter of 1.75 inches which is too large to enter the anal canal (without applying excessive force) and which thus abuts and occludes the anal opening  44  when the proximal portion  14  is inserted completely into the anus  40 . The expanded portion  18  thus serves to both limit the extent to which the air introduction device  10  is inserted into the rectum  42  and occlude the anal opening  44  to prevent leakage of air around the air introduction device  10 . The distal portion  16  has an inner diameter of approximately 0.375 inches, which joins easily with an inexpensive disposable insufflation bulb  24 , which is commercially available, by means of the tubing connector  26  of the insufflation bulb  24 .  
         [0055]     These dimensions, while allowing for optimal performance, also permit the air introduction device to be formed by a dip molding process, which is less expensive than other molding processes (e.g. injection molding). If the proximal portion  14  were appreciably thinner, or if the maximum diameter  18   a  of the expanded portion  18  were appreciably larger, the mandrel, around which the elastomeric device is molded, could not be readily removed from the device (unless the walls of the device were made thinner, which would render the device too flimsy for use.)  
         [0056]     Referring now to  FIGS. 6-10 , a second embodiment of an air introduction device in accordance with the invention is designated generally as  52  and comprises a unitary body  54  defining an interior space  54   a  and having a proximal segment or portion  56  and a distal segment or portion  58  separated from the proximal portion  56  by an expanded segment or portion  60 . The body  54  of the air introduction device  52  may be made of an elastomer compatible for contact with internal parts of the human body and fabricated using a dip molding technique to obtain a soft, pliable form. Other plastic manufacturing methods can also be used.  
         [0057]     The proximal portion  56  has a substantially uniform inner and outer diameter with the exception that a tip  62  is rounded or tapered to aid insertion of proximal portion  56  into the anus of an anesthetized patient. The distal portion  58  has two arms  64 , 66  extending from the expanded portion  60 . Expanded portion  60  has an outer circumferential portion  60   a  having the largest diameter thereof and which is dimensioned to be larger than the opening of most human anuses when they are maximally dilated so that the air introduction device  52  cannot be inserted into the anus farther than the circumferential portion  60   a . The expanded portion  60  includes two truncated conical surfaces  68   a ,  68   b , one surface  68   a  tapering from the outer circumferential portion  60   a  toward the rear edge of the proximal portion  56  and one surface  68   b  tapering from the outer circumferential portion  60   a  toward the front edge of the distal portion  58 .  
         [0058]     The first arm  64  on the distal portion  58  constitutes an insulation side arm defining an insufflation port whereas the second arm  66  constitutes an endoscopic side arm defining an endoscopic port. More specifically, the first arm  64  has a distal end  70  and lumen  72  which is designed to receive the connector  26  of the insufflation bulb  24  (the same as shown in  FIG. 3 ) and communicates with the interior space  54   a  of the body  54 . The second arm  66  defines a lumen  74  between the interior space  54   a  and a closed end  76 . The lumen  74  is separated from the interior space  54   a  by a constriction  78 , which may be approximately 10 mm in diameter. In the non-limiting illustrated embodiment, a longitudinal axis of the second arm  66  (designated L 1 ) is parallel to a longitudinal axis of the proximal portion  56  and the expanded portion  60  (designated L 2 ), but offset therefrom.  
         [0059]     The air introduction device  52  may include the same features as the air introduction device  10  described above, to the extent possible.  
         [0060]     In one exemplifying use to test whether an anastomosis  48  is leak-proof, the air introduction device  52  is coupled to the insufflation bulb  24  by inserting connector  26  of the insufflation bulb  24  into lumen  72  of the distal portion  58  of the air introduction device  52  to thereby form the anastomotic leak tester  80  shown in  FIG. 8 . The proximal portion  56  of the air introduction device  52  is then inserted into the anus  40  of an anesthetized patient (see  FIG. 10 ). The pelvis is filled with fluid and the bowel above the anastomosis is occluded with clamp  49 . The insufflation bulb  24  is compressed several times, distending the rectum  42  with air. As explained above, air cannot escape from the anus  40  because of the seals formed by the proximal portion  56  of the air introduction device  52  against the anal wall and the expanded portion  60  of the air introduction device  52  against the anal opening  44 . When the rectum  42  is sufficiently distended with air, and no air bubbles are seen in the pelvic fluid, it is can be considered that the anastomosis  48  is air tight and leak-proof. The air introduction device  52  is then removed from the anus.  
         [0061]     A second way to evaluate the anastomosis involves a visual inspection of the internal aspect of the anastomosis  48 . To this end, the closed end  76  of the second arm  66  is severed off, for example, with a scissors at point  82  between the closed end  76  and a location where the second arm  66  joins the first arm  64 .  
         [0062]     A laparoscope  84  is then inserted into lumen  74  so that the tip or proximal end  86  of the laparoscope  84  sits within space  54 a of the body  54 . The laparoscope  84  is attached to a fiberoptic cable  88  which is connected to a light source (not shown). Laparoscope  84  may be attached to a camera  90  which is connected to an image processor (not shown) and video display (not shown). The proximal portion  56  of the air introduction device  52  (attached to the insufflation bulb  24 ) is then inserted into the anus  40  so that the expanded portion  60  abuts against the anal verge  44 . The insufflation bulb  24  is compressed several times, distending the rectum  42  with air. The tip  86  of the laparoscope  84  is then advanced from the position in the space  54   a  in the elastomeric body  54  into the rectum  42  while viewing the advancing progress directly through the lense of the laparoscope or on a video display to a point that permits a clear picture of the anastomosis  48  (see  FIG. 10 ).  
         [0063]     The constriction  78  serves to provide a seal against the laparoscope  84  to prevent air and fluid in the interior space  54   a  from being released from the body  54  via the lumen  74 .  
         [0064]     A laparoscope with an angled tip may be used, and the laparoscope may be rotated to obtain an excellent view of the inner aspect of the bowel anastomosis  48  on the video display. Bleeding from the anastomosis  48  can be easily identified and anastomotic defects visualized. Corrective surgical action can then be taken.  
         [0065]     When the visual inspection is complete, the laparoscope  84  is removed with the leak tester  80  remaining in place. The rectum  42  is deflated and then the leak tester  80  removed out of engagement with the patient.  
         [0066]     Referring now to  FIG. 11 , a third embodiment of an air introduction device in accordance with the invention is designated generally as  92  and comprises a unitary body  94  defining an interior space  94   a  and having a proximal segment or portion  96  and a distal segment or portion  98  separated from the proximal portion  96  by an expanded segment or portion  100 . The body  94  of the air introduction device  92  may be made of an elastomer compatible for contact with internal parts of the human body and fabricated using a dip molding technique to obtain a soft, pliable form. Other plastic manufacturing methods can also be used.  
         [0067]     The proximal portion  96  has a substantially uniform inner and outer diameter with the exception that a tip  102  is rounded or tapered to aid insertion of proximal portion  96  into the anus of an anesthetized patient. The distal portion  98  has two arms  104 ,  106  extending from the expanded portion  100 . Expanded portion  100  has an outer circumferential portion  100   a  having the largest diameter thereof and which is dimensioned to be larger than the opening of most human anuses when they are maximally dilated so that the air introduction device  92  cannot be inserted into the anus farther than the circumferential portion  100   a . The expanded portion  100  includes two truncated conical surfaces  108   a ,  108   b , one surface  108   a  tapering from the outer circumferential portion  100   a  toward the rear edge of the proximal portion  96  and one surface  108   b  tapering from the outer circumferential portion  100   a  toward the front edge of the distal portion  98 .  
         [0068]     The first arm  104  on the distal portion  98  constitutes an insufflation side arm defining an insufflation port whereas the second arm  106  includes a pressure relief valve  110  arranged in a lumen  118 . The first arm  104  has a distal end  112  and a lumen  114  which is designed to receive the connector  26  of the insufflation bulb  24  (the same as shown in  FIG. 3 ) and communicates with the interior space  94   a  of the body  94 .  
         [0069]     Valve  110  is a pressure relief valve which allows air to escape from the rectum  42  when a specific air pressure within the rectum  42  is reached. This prevents over-inflation of and damage to the rectum  42 . A bill-shaped extension  115  is attached to a distal end  116  of the second arm  106  and may be separately formed from an elastic material such as rubber and fixed to the distal end  116  of the second arm  106  by an adhesive or other comparable attachment mechanism.  
         [0070]     When air escapes the rectum  42  through the second arm  106 , i.e., through valve  110 , it passes through extension  115  causing upper and/or lower flaps  117  of the extension  115  to vibrate. This produces an audible signal which alerts the surgeon to the fact that the desired air pressure within the rectum  42  has been reached. Other mechanisms for causing an audible (e.g. a whistle) or visual indication when air is released via pressure relief valve  110  can be used instead of the flaps  117 .  
         [0071]     Alternatively, the extension  115  may be designed to permit passage of air between the flaps  117  only when a specific air pressure is reached in the rectum. That is, the extension  115  may function both as a pressure release valve and a mechanism to produce an audible signal. In this case, a separate pressure relief valve  110  is not necessary and not provided, as shown in  FIG. 12 .  
         [0072]     The air introduction device  92  may include the same features as the air introduction devices  10 ,  52  described above, to the extent possible.  
         [0073]     In another embodiment of the invention, the distal portion of the body may include three arms, an insufflation port on one arm (for mating with an insufflation bulb or other pumping device), an endoscopic port on another arm (for enabling passage of an endoscope therethrough) and a third arm containing a pressure relief valve and signal producing extension.  
         [0074]     While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.