Abstract:
A hollow plastic cannula with plunger having a funnel shape entrance at one side and a sharp slant cut on the other. A hollow polyethylene catheter is shaped to fit within the cannula once inserted in the abdomen. The present invention is a means of performing an error-free abdominal insufflation for Laparoscopic procedures.

Description:
RELATED APPLICATION  
       [0001]    This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 11/396,725, filed Apr. 3, 2006. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]    Laparoscopy is the operative procedure that allows the surgeon to view the abdominal cavity with a long rod-type scope (Laparoscope), to perform operations without the need of employing large incisions. The Laparoscope is inserted through a small incision around the navel. Before the Laparoscope can be inserted, the abdominal cavity has to be insufflated with CO 2  to allow the introduction of a large trocar (the Principal Trocar-Cannula Unit) which provides the portal for the introduction of the Laparoscope. To accomplish this initial phase of this procedure, to create a pneumo-peritoneum, the surgeon inserts in or around the navel a Veress needle. This is a rigid, metallic needle, of ten, twelve, fifteen or seventeen cm of length, and two mm in diameter. This needle is pushed through the anterior abdominal wall until it is several centimeters inside the abdominal cavity. If the needle is successfully placed into the free space of the abdominal cavity the process of insufflation proceeds uneventfully. 
         [0003]    In order to ascertain that the Veress needle is inside the abdominal cavity, surgeons “test” the position of the needle employing various maneuvers. There are several such tests. One is “manometer test”, which involves the connection of the Veress needle to the insufflating system and by pulling up the anterior abdominal wall with towel clips the operator observes if a negative pressure is registered in the system&#39;s manometer. Another maneuver is the “hanging drop test”, which consists of placing water at the upper end of the Veress needle and seeing if the drop of water is sucked inside the needle by the vacuum in the abdominal cavity. A third test is the “hissing sound test”, in which the operator turns the valve in the Veress needle to the off position and then opens it. He then lifts the anterior abdominal wall with towel clips to suck air from the needle into the abdominal cavity. He is supposed to hear the hissing sound of the air going inside the needle. Another test is injecting air inside the Veress needle with a syringe to see if it goes easy. An easy injection means the needle is in the abdominal cavity. Another test is the injection of a small amount of water. In this maneuver, the surgeon first aspirates the needle with a syringe. If no blood or bowel content is obtained, the surgeon then injects a small amount of sterile water and aspirates again. If the water is re-aspirated, it means that the operator is in an enclosed space, not the free space of the abdominal cavity. One more maneuver is the “double-click test”. In this test, the operator should hear two distinct clicks as the needle traverses critical layers of the anterior abdominal wall. If this double-click is heard, it is reassuring that the needle is in the abdominal cavity. The most sensitive of all tests seems to be the detection of a high insufflating pressure in the laparoscopy system. Modern equipment is good in detecting unusually high pressure when the needle is not in the right place but even this last test is not free of frequent errors. This high-pressure indicator is not reliable and the creation of subcutaneous emphysema or pnemo-omentum may still occur in spite of a seemingly low pressure in the system. 
         [0004]    Very often all of these testing maneuvers eventually fool the operator into believing that he or she is in the right place when, indeed, the needle is not in the free-space of the abdominal cavity but in the thickness of the anterior abdominal wall or hitting an intra-abdominal structure. None of these maneuvers guarantee successful access to the free space of the abdominal cavity. If insufflation is done when the Veress needle is within the thickness of the anterior abdominal wall, a subcutaneous emphysema is then created and, if not recognized immediately, it becomes of a significant size and subsequent attempts to inflate the abdominal cavity become increasingly more difficult. 
         [0005]    After the insertion of the Veress needle, the initiation of the insufflation is started. Surgeons usually begin to inflate with a low flow of CO 2 . After a wait of a few seconds the surgeon sees if the characteristic tympanic sound is heard on percussion of the abdomen, generally on all four quadrants of the anterior abdominal wall. During this waiting period he also perceives with his hand the typical drum-like resilience of the anterior abdominal wall on percussion when the cavity is filled with gas. The operator then proceeds to continue the insufflation at a high gas flow. The fact remains that before accurate abdominal insufflation is achieved, there is a good degree of anxiety created by the doubt, hesitancy, uncertainty and fear of failure that assails the surgeon because he is not absolutely sure that the tip of the needle is in the right place. This doubt prompts him to remove and re-insert the Veress needle until he is “reasonably” sure he is in the right space to cautiously let the insufflation begin. 
         [0006]    To this day, the creation of unwanted subcutaneous emphysema remains a problem in Laparoscopic procedures. The more obese the patient is, the greater the chances of its occurrence. Besides the above-mentioned drawbacks, there are other complications associated with the Veress needle. One is the creation of pneumo-omentum, which is the instillation of CO 2  into the thickness of the omental flaps. Another complication is the accidental puncture of intestines or the injury to blood vessels. Because the Veress needle has to be inserted several centimeters inside the abdominal wall, if the patient is thin, the risk of accidental puncture of a major blood vessel is greatly increased. All textbooks of laparoscopy warn surgeons about the exceedingly close proximity of the anterior abdominal wall to the major vessels in these thin patients, particularly at the level of the navel, the site of insertion of the Veress needle. 
         [0007]    In an effort to overcome these series of obstacles associated with the trans-abdominal insertion of the Veress needle, surgeons all over the world have tried other ways to access the abdominal cavity with the Veress needle. In obese patients they insert the Veress needle trans-vaginally to reach the cul-de-sac, or even directly through the fundus of the uterus. In some countries, the gas-less Laparoscopy has been introduced. 
         [0008]    Various modifications to the Veress needle have been invented. One is the Veress-Frangenheim needle, which is double-barreled to permit insufflation while at the same time measure the pressure around the needle. Another is the Foures-Kuss needle, which has lateral holes that permit insufflation even if the needle tip is hitting an obstacle. None of these varieties is now in use, and furthermore, they are subject to the same failure of creating subcutaneous emphysema or injury to internal organs as the original Veress needle. 
         [0009]    To avoid all the problems associated with the use of the Veress needle, Harrit Hasson in 1972 introduced the Open Laparoscopy. In this alternative, the Veress needle is entirely avoided and, instead, the abdominal cavity is entered in the traditional way via a small incision below the navel to allow the insertion of the trocar carrying the portal to the Laparoscope. Currently, however, the Veress needle is, by far, the preferred method being used but it is, unfortunately, not devoid of its attendant risk of failure due to misplacement of the needle in the thickness of the anterior abdominal wall or potential injury to internal structures. 
         [0010]    The present invention solves easily, safely, quickly, and error-free, all the problems associated with the use of the Veress needle for abdominal insufflation for Laparoscopy, namely, the creation of subcutaneous emphysema or pneumo-omentum, and the risk of injury to intra-abdominal structures. If a safe and effective pneumo-peritoneum can be created by the invention, there is no need for open Laparoscopies. 
         [0011]    Insertion of the large Principal Trocar-Cannula unit, once the abdomen is successfully inflated, is not devoid of difficulties and complications. These Principal Trocar-Cannula units have either sharp blades or sharp points at their tips. Insertion has to be done by forcibly pushing them through the anterior abdominal wall. It is literally a blind thrust of this unit well inside the abdominal cavity. Sometimes the insertion is difficult due to resistant abdominal walls, or it may go too fast inside the abdomen. It is a known fact that the force applied for the insertion has to be greater than the resistance of the inflated abdominal wall. Although complications with the insertion of the Principal Trocar-Cannula unit are significantly rare, when they occur they tend to be very serious. 
       SUMMARY OF THE INVENTION  
       [0012]    The invention is first directed to an abdominal insufflator, comprising an elongated, hollow cannula having an inclined tip at one end, an open opposite end, and a plunger shaped to be engaged in and co-extensive with the cannula, the plunger having an inclined tip at one end and an engagement end shaped to conform to the open opposite end of the cannula. A system is provided for aligning the plunger when engaged within the cannula. 
         [0013]    In accordance with the preferred form of this part of the invention, the open opposite end of the hollow cannula is funnel-shaped. Similarly, the engagement end of the plunger is funnel-shaped. The funnels are sized to fit within one another. 
         [0014]    The aligning system comprises a notch in the open opposite end of the hollow cannula and a protrusion in the insertion end of the plunger. The protrusion is shaped to fit within the notch. 
         [0015]    To facilitate utilization of the insufflator, a pair of grasping rings is located on opposite sides of the opened opposite end of the hollow cannula. A guide ring is formed at the engagement end of the plunger. 
         [0016]    In the preferred form of this part of the invention, the abdominal insufflator is part of a system which includes a catheter which is shaped to fit within the hollow cannula. The catheter has a length considerably greater than that of the hollow cannula, and includes a flow control for gas control through the catheter. 
         [0017]    The invention also includes an abdominal trocar, comprising an elongated, hollow cannula having an inclined tip at one end, an opposite end, and a plunger shaped to be engaged in and co-extensive with the cannula, the plunger having an inclined tip at one end and an engagement end shaped to conform to the opposite end of the cannula. A system is provided for aligning the plunger when engaged within the cannula. A valve system is provided at the opposite end. 
         [0018]    In this form of the invention, the valve system includes an inlet in alignment with and shaped to be engaged by the plunger. The inlet comprises a normally-closed valve, which comprises a plunger-accommodating tube and a hinged lid engaging a seat to sealingly close the tube, and a spring urging the lid against the seat. The valve system also includes a normally-closed outlet valve. 
         [0019]    In this form of the invention, the aligning system comprises a protrusion in the opposite end and a notch in the engagement end, with the protrusion being shaped to fit within the notch. 
         [0020]    In both forms of the invention, the cannula may have an exterior insertion thread. 
         [0021]    A system according to the invention comprises the combination of the abdominal insufflator and the abdominal trocar. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0022]      FIG. 1  is an oblique upper view of the hard plastic cannula of the invention. 
           [0023]      FIG. 2  is a panoramic view of the cannula&#39;s plunger. 
           [0024]      FIG. 3  is an enlarged view of the plastic cannula&#39;s funnel depicting the notch it bears in its outer edge. 
           [0025]      FIG. 4  is an enlarged view of the plunger&#39;s head showing the ring attached to its flat upper surface. 
           [0026]      FIG. 5  is a panoramic view of the elongated polyethylene catheter of the invention, coiled for purposes of illustration. 
           [0027]      FIG. 6  shows the surgeon&#39;s hands appropriately holding the cannula and plunger while the surgeon traverses the thickness of the anterior abdominal wall around the navel. 
           [0028]      FIG. 7  is an elevational view of the hard plastic cannula of a second form of the invention. 
           [0029]      FIG. 8  is a side view of the cannula of  FIG. 7 . 
           [0030]      FIG. 9  is a top plan view of the cannula of  FIG. 7 . 
           [0031]      FIG. 10  is an elevational view of the cannula&#39;s plunger. 
           [0032]      FIG. 11  is a side elevational view of the plunger of  FIG. 10 . 
           [0033]      FIG. 12  is a top plan view of the plunger of  FIG. 10 . 
           [0034]      FIG. 13  is a panoramic view of the elongated polyethylene catheter of the invention, essentially similar to that shown in  FIG. 5 . 
           [0035]      FIGS. 14 ,  15  and  16  are, respectively, front elevational, side elevational and top plan views of a plunger used with the cannula of  FIGS. 17-24 . 
           [0036]      FIG. 17  is an elevational view of a plastic cannula for a trocar. 
           [0037]      FIG. 18  is a side elevational view of the cannula of  FIG. 17 . 
           [0038]      FIG. 19  is a top plan view of the cannula of  FIG. 17 . 
           [0039]      FIG. 20  is an elevational view similar to  FIG. 17 , but being cut away to show detail of a portion of the valve system for the cannula. 
           [0040]      FIGS. 21-24  illustrate, in greater detail, the valve system shown in  FIG. 20 , and the parts thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0041]    The present invention is shown generally in the drawing figures, and that portion illustrated in  FIGS. 1-6  consists of three separate parts: 
         [0042]    The first part is a hollow, hard plastic cannula  10  with a small funnel  12  at its upper end, and an inclined or a sharp-pointed slant tip  14  at its low end. At the upper end of the plastic cannula, next to the small funnel, are two diametrically positioned rings  16  and  18  for better grasping, like holes of a scissors. The edge of the free border of the funnel  12  has one small notch  20  placed at mid-point between the two lateral rings  16  and  18 . 
         [0043]    The second part is a plastic plunger  22  whose shape mimics the configuration of the hollow inner-space of the cannula  10  and fits perfectly inside it, culminating in an inclined or a sharp tip  23  shaped to conform to the tip  14 . It has a ring  24  at its upper engagement end, made of the same plastic material, attached and continuous with the flat upper surface  26  of the plunger  22 . The flat surface  26  of the plunger  22  has a small protrusion  28  on the edge of the surface. This protrusion  28  fits perfectly in the notch  20  provided in the upper edge of the funnel  12 , the notch  20  and protrusion  28  providing an alignment system. 
         [0044]    The third part of this form of the invention is a long hollow polyethylene catheter  30  which ends freely at one end with a soft, smooth rounded tip  32 . At the other end of the catheter, it is continuous with a female-type syringe connector  34 , preceded by a flow control in the form of a stop-cock valve  36 . This end of the catheter  30  is to be connected to the insufflating system of the Laparoscopy equipment (not illustrated, but conventional). 
         [0045]    To perform an easy, safe quick and error-free abdominal insufflation, the surgeon has to first assess the thickness of the anterior abdominal wall by grasping its paniculus on both sides of the navel with the fingers and have a rough idea of its size. He then makes a longitudinal incision of approximately  6  mm, two centimeters above or below the navel, according to the nature of the Laparoscopic procedure. If the Laparoscopic procedure is in the upper abdomen, like a Cholecystectomy, the incision should be two centimeters below the navel, and vice versa. If the operation is in the lower abdomen, the incision for the cannula is done two cm above the navel. 
         [0046]    The surgeon then asks his assistant to elevate as much as possible the umbilical area of the anterior abdominal wall with two towel clips placed two centimeters lateral to the incision. As shown in  FIG. 6 , he then holds the upper third of the cannula&#39;s stem with his left hand and inserts his middle finger inside one of the cannula&#39;s rings  18 , and the thumb of the same hand inside the opposite ring  16 . His index finger enters the guide ring  24  on top of the plunger  22  and presses it down to keep it in its position inside the cannula  10 . When the plunger fits completely inside the cannula  10  it provides solidity to it, and in this way it prevents tissue or any other material from entering the cannula. 
         [0047]    The surgeon then inserts vertically and slowly the plastic cannula  10  with its plunger  20  in place into the abdominal wall in a fashion similar to that employed for the insertion of the Veress needle. When the surgeon calculates that he has traversed approximately eighty percent of the anterior abdominal wall, he proceeds to advance the cannula-plunger unit by thrusting it, centimeter by centimeter, through the remainder twenty percent of the anterior abdominal wall&#39;s thickness. After every thrust, he removes the plunger  20  and inserts the polyethylene catheter  30  inside the cannula  10  and taps the bottom of the cannula  10  in a knocking fashion to see if it enters the abdominal cavity. If the catheter  30  doesn&#39;t go inside the abdominal cavity, he then removes the polyethylene catheter  30  and re-inserts the plunger  20 . He thrusts down the cannula-plunger unit again one more centimeter and repeats the previously described knocking maneuver with the catheter  30  until it finds no resistance and freely enters the abdominal cavity. 
         [0048]    The surgeon then proceeds to pass the polyethylene catheter 15 or 20 cm beyond the anterior abdominal wall. At this time the surgeon pulls back the plastic cannula  10  while he holds firmly with the other hand the polyethylene catheter  30  inside the abdomen. Next, his assistant releases the pull on the towel clips to allow the anterior abdominal wall to return to its resting position. 
         [0049]    Successful insufflation of the abdomen can now be absolutely assured because the tip of the polyethylene catheter  30  lies freely and safely deep inside the abdominal cavity, more than fifteen centimeters beyond the formerly troublesome area, the anterior abdominal wall. Additionally, the soft, smooth, rounded end  32  of the polyethylene tube, combined with its slow, small-increments insertion through the anterior abdominal wall is devoid of the risk of injury to any internal organs as well as being incapable of creating pneumo-omentum. 
         [0050]    In this form of the present invention, if the technique of insertion is followed as described, the sharp tip  14  of the cannula  10  should not reach more than one cm beyond the inner surface of the anterior abdominal wall and, consequently, could never injure anything inside the abdomen. The exception to this rule is the possibility of a bowel firmly attached to the anterior abdominal wall at the site of insertion of the cannula  10 . This exceptional situation is easily avoided by not using a previous scar as the site for insertion of the cannula  10 . The hesitancy, doubt, uncertainty and fear of failure that assail the surgeon are totally eliminated by the invention. Likewise, the trial and error associated with the insertion and re-insertion of the Veress needle through the abdominal wall until the surgeon thinks he is inside the free space of the abdominal cavity, is also eliminated. Once the abdominal wall has been sufficiently inflated, the polyethylene catheter  10  remains inside the abdomen while the subsequent steps of the operations go on. 
         [0051]    Another advantage of the present invention over the Veress needle is as follows. When the abdominal cavity has been successfully inflated with the Veress needle, this needle is then totally removed from the abdomen. The same incision used for the Veress needle is then made larger to allow the insertion of the large Laparoscopic trocar. Once the Veress needle is out, the gas starts to decrease either by diffusion or by escape through the orifice left by the Veress needle. If the insertion of the large trocar is not successful the first time and the surgeon tries to re-insert it, the time involved in this process may allow the abdomen to deflate even more, making the subsequent attempts to insert the trocar significantly riskier. Contrary to the employment of the Veress needle, the site of insertion of the large trocar is far away from the one used by the polyethylene catheter  30  which lies safely inside the abdomen providing continuous abdominal insufflation. In case that the insertion of the large trocar is not successful, the abdominal cavity will never deflate. No matter how many times the surgeon tries to re-insert the trocar an additional advantage of the invention is that it can create a safe and effective pneumo-peritoneum without the need to do open Laparoscopies. 
         [0052]    A second form for the invention is illustrated in  FIGS. 7-13 . This form of the invention is quite similar to that of  FIGS. 1-6 , with exceptions that will become apparent in the following description. 
         [0053]    This form of the invention also consists of three parts, the first part being a hollow, hard plastic cannula  40  with a small funnel  42  at its upper end and an inclined tip  44  at its lower end. Similar to the first form of the invention, two diametrically opposed rings  46  and  48  are provided for better grasping. One of the rings has an extension  50  adjacent the edge of the funnel  42 , as illustrated. 
         [0054]    The cannula  40  has a helical external thread  52  having spaces  54  between thread convolutions. For determining depth of insertion, the cannula  40  can include numbers or other marking to represent depth, as illustrated in  FIG. 7 . 
         [0055]    The funnel  42  has an internal cylindrical bore  56  extending the length thereof, from the tip  44  to the top of the funnel  42 . 
         [0056]    The plunger  58  is essentially identical to the plunger  22  of the first form of the invention, and fits in the bore  56 . The plunger  58  has a tip  60  which is shaped to conform to the tip  44 . The plunger has a head  62  which is essentially rectangular with a notch  64  in one of its sides corresponding to the protrusion  50 . Wings  66  and  68  may be provided for manipulation of the plunger  58 . 
         [0057]      FIG. 13  illustrate the catheter used in combination with the cannula  40 . The catheter is identical to the catheter  30  of  FIG. 5 , and is therefore not described in greater detail. 
         [0058]      FIGS. 14-24  depict the abdominal trocar, also known as the principal trocar-cannula of the invention.  FIGS. 14-16  illustrate the plunger for this form of the invention,  FIGS. 17-19  illustrate the cannula for this form of the invention, and  FIGS. 21-24  illustrate the one way valve for the cannula. 
         [0059]    The plunger  70  is composed of two parts, a head  72  and a stem  74 . The stem, opposite the head  72 , terminates at a slanted tip  76  as illustrated. The head  72  includes a notch  78  on one side. 
         [0060]    The cannula  80  of  FIGS. 17-19  includes a tube  82  having an internal bore  84  shaped to accommodate insertion of the plunger  70 . As illustrated, the tube  82  terminates, at its lower end, at a tip  86  shaped so that when the plunger  70  is inserted, the tip  76  of the plunger  70  and the tip  86  of the cannula  80  form a single, inclined tip. 
         [0061]    The tube  82  has a helical thread  88  on its outer wall. The helical thread  88  is similar in form and function to the thread  52  of the cannula  40 . And the helical thread  88  extend from proximate the tip  86  to a square collar  90 . 
         [0062]    Above the collar  90 , a chamber  92 , having extended wings  94  and  96 , is located. The chamber  92  has a roof  98  with a central aperture  100 . A sealing ring is embedded in the aperture  100 . 
         [0063]    As best illustrated in  FIG. 20 , with parts illustrated in  FIGS. 21-24 , a one way valve  104  extends beneath the aperture  100 . The valve  104  include a tube  106  with a slanted lower end  108  with a sealing ring  110  embedded in the lower end  108 . A door  112 , biased by a spring  114 , closes against the slanted end  108 , sealed by the ring  110 . The door  112  includes a transverse rod  116 , as best illustrated in  FIG. 23 , which fits beneath a bracket  118  on the underside of the roof  98 . The spring  114  biases the door  112  in the closed position shown in  FIG. 20 . 
         [0064]    The cannula  80  also includes a conventional on/off valve  120  communicating with the bore  84 . The valve  120  can be turned on or off in a known manner in order to allow air to be expelled from the cannula  80 . 
         [0065]    The cannula  40  is used in a manner identical to that of the cannula  10  of  FIGS. 1-6 . However, its installation is slightly different. Once a patient is under anesthesia, an appropriate incision is made in the abdomen. The cannula  40 , with the plunger  58  therewithin, is inserted in the incision, and the practitioner, using the helical thread  52 , screws the cannula clockwise toward the abdominal cavity. The insertion is therefore by small increments, until the abdominal cavity is entered. By virtue of this gradual insertion, the operator is sure that the tip  44  will never be inserted beyond the inner surface of the abdominal wall. Thus, nothing inside the abdominal cavity can be injured. Once insertion has been completed, the plunger  58  is removed and the catheter  30  is inserted, as described above. 
         [0066]    The cannula  80  is then installed. Abdomen has been distended through use of the catheter  30 , an incision is made below the navel, and the cannula  80 , with plunger  70  in place, is inserted inside the incision. Then, similar to installation of the cannula  40 , the cannula  80 , due to its helical thread, is screwed downwardly, until the surgeon determines that it has traversed about  80  percent of the thickness of the abdominal wall. The surgeon then proceeds to open the valve to see if gas escapes. If not, the surgeon continues to screw gradually further downwardly in small increments, opening the valve  120  after each interval. Once gas comes out the valve  120 , the cannula  80  has been properly installed in the abdominal cavity. By advancing gradually in small increments, the surgeon is sure that the tip  86  will never be inserted too far beyond the inner surface of the abdominal wall. Thus, no intra-abdominal organs will be injured. Once the cannula  80  is in place, the plunger  70  is removed and any instrument to be used in the surgical procedure (not illustrated) can be passed through the port  84  to be used in a conventional fashion. 
         [0067]    Various changes can be made to the invention which don&#39;t depart from the spirit thereof or scope of the following claims.