WO1997006732A1

WO1997006732A1 - Device and method for laparoscopic inguinal hernia repair

Info

Publication number: WO1997006732A1
Application number: PCT/IB1996/000700
Authority: WO
Inventors: Salomon Benchetrit
Original assignee: Salomon Benchetrit
Priority date: 1995-08-17
Filing date: 1996-07-15
Publication date: 1997-02-27
Also published as: EP0845961A1; US5681342A; AU6314696A; ATE241318T1; DE69628437D1; ES2199292T3; DE69628437T2; EP0845961B1

Abstract

A laparoscopic surgical separating device (1) for creating a preperitoneal workspace, for use in preperitoneal laparoscopic inguinal hernia repair, comprising relatively rigid longitudinal element (2), a longitudinal axis (5), an interior wall (6) defining a throughbore (7), an inflatable element (8) fixedly attached to a point (9) along the length of an outer wall (10) of element (2), fluid insufflation means (11), connected to inflatable element (8), and to throughbore (7), and sealing means (12) capable of preventing fluid from escaping from element (2), wherein inflatable element (8) is of generally asymmetrical shape, having, on one side of said axis (5), a relatively large portion (13) of inflatable material, and on the other side of said axis (5) in the same plane, a relatively small portion (15) of inflatable material, the portions (13, 15) corresponding to the space available in the body after insertion and inflation of the device (1) via an incision (16) made at the antero-superior iliac crest (17).

Description

DEVICE AND METHOD FOR LAPAROSCOPIC INGUINAL HERNIA REPAIR

The present invention concerns a device used in laparoscopic surgery, in particular, laparoscopic inguinal hernia repair surgery, and a method of carrying out such surgical repair.

Laparoscopic or keyhole surgical interventions have recently taken on increasing importance as surgeons have realized the benefits, both in terms of cost and patient comfort, of minimal invasive surgical techniques. Accordingly, there has been a constant development in the techniques used in this type of surgery and the equipment necessary to successfully carry out such operations.

In the particular field of hernia repair, the application of preperitoneal laparoscopic techniques has enabled surgeons to obviate many of the dangers of traditional open bowel surgery, and even intraperitoneal laparoscopy, since the technique doeε not involve the risk of the surgeon damaging a sensitive organ with one of the inserted instruments. The basis for this technique lies in separating two layers of tissue, namely the peritoneum from the overlying abdominal wall, and creating a sufficiently large working preperitoneal space therebetween to enable the surgeon to carry out the hernia repair. At present, and for inguinal-hernia repair, the operative procedure is the following. Such a procedure is known from EP-A-0 573 273, the disclosure of which is hereby incorporated by reference for the teachings of such procedure therein. After anaesthetization and preparation of the patient, a first incision is made infra-umbilically in the skin below the navel or umbilicus, the fat layer is separated, and the incision continued through to the anterior surface of the posterior rectus sheath in the midline. A separating device is introduced laterally between the peritoneum and the rectus muscles, and tunnelled toward the symphysis pubis.

This device generally comprises at least one relatively rigid longitudinal element having distal and proximal ends, defining a longitudinal axis, the interior wall of which defines at least one throughbore, an symmetrical inflatable element fixedly attached to at least one point along the length of the outer wall of said longitudinal element, fluid insufflation means connecting with the inflatable element and capable of inflating said element, and via the at least one throughbore, enabling creation of a pneumoperitoneum in the preperitoneal cavity formed by the separation of said peritoneum and said overlying abdominal wall when fluid is insufflated therethrough, and sealing means capable of preventing the insufflated fluid from escaping via the proximal end of the relatively rigid longitudinal element.

This device is advanced to preferably be disposed between the bladder and the symphysis pubis by tunnelling as mentioned previously. Once in position, the symmetrical inflatable element, which before deployment is in a rolled up configuration, is inflated with fluid. The inflatable element progressively unwraps equally from both sides of the longitudinal element and expands along a plane to cause progressive separation or dissection of tissue along its weakest points by application of forces generally perpendicular to the plane of the inflatable element, thereby creating a preperitoneal space. When complete inflation is achieved, the inflatable element is deflated, withdrawn and replaced by a conventional laparoscope. The dissected preperitoneal space is then insufflated with carbon dioxide via the insufflation means, and two additional trocars are inserted through the abdominal wall into the dissected preperitoneal workspace, one immediately above the symphysis pubis, and the other to the left or right side of the abdomen depending on the site of the hernia to be repaired. Subsequently, the hernial sac is dissected from the surrounding tissue, in particular, the spermatic duct and vessels, and a hernia repair prosthesis, generally in the form of a synthetic patch or graft, is placed across the inguinal ring and around said vessels and stapled to keep it in place. The preperitoneal workspace is then deflated, by release of the insufflated carbon dioxide, under laparoscopic observation, and the instruments withdrawn. At the same time, the abdominal wall and peritoneum return to their initial position, the original incisions necessitating only small sutures with consequently limited scarring.

The major disadvantage of the above method and device is related to the tunnelling step. Indeed, the traumatic character of the technique is dependent on the careful manipulation of the device by the surgeon during the tunnelling step. If this step is carried out hurriedly, it is likely that the device will puncture or tear through the underlying peritoneum, risking damage to an organ of the body, or at least traumatising the peritoneum. Consequently, an atraumatic tunnelling is necessarily very time consuming and fastidious.

Summary of the Invention It is an object of the present invention to overcome the disadvantages of the prior art by providing a device and surgical method enabling a relatively rapid atraumatic separation of the peritoneum from the overlying abdominal wall, without the need for the potentially dangerous tunnelling step, thereby facilitating the surgeon's task.

It is therefore an object of the invention to provide a laparoscopic surgical separating device adapted to separate the peritoneum from the overlying abdominal wall, thereby permitting access to a preperitoneal operative site, for use in preperitoneal laparoscopic inguinal hernia repair, comprising at least one relatively rigid longitudinal element having distal and proximal ends, defining a longitudinal axis, the interior wall of which defines at least one throughbore, an inflatable element tightly surrounding at least a distal part of the outer or interior walls of said at least one longitudinal element, inflating means communicating with the inflatable element and capable of inflating said element, wherein the inflatable element can adopt a first, flattened deflated configuration for its introduction, and a second, substantially planar inflated configuration along a median plane to provide a separating force perpendicular to said median plane when the inflatable element is inflated, thereby enabling the separation of the peritoneum and the overlying abdominal wall to create a preperitoneal workspace, the inflatable element being disposed around said longitudinal axis, and along said at least longitudinal element over a predetermined distance, wherein said inflatable element has a generally asymmetrical shape, which shape is defined by the element having, on one side of said axis, a relatively large and substantially flat surface area, and on the other side of said axis, a relatively small substantially flat surface area, whereby said surface areas correspond to the space available in the body after insertion of the device via an incision made at the antero-superior iliac crest.

It is a further object of the invention to provide a method for separating the peritoneum from an overlying abdominal wall and creating a preperitoneal workspace permitting access to a preperitoneal operative site, comprising:

(a) making a first traversing incision in the abdominal walls far as the anterior surface of the peritoneum, in the vicinity of an antero-superior iliac crest, homolateral to the hernia to be repaired ; (b) introducing a separating device horizontally into the incision thus made, thereby entering the preperitoneal region ; (c) causing the device to expand more towards the opposite facing side of the body than to the side of introduction, whereby separation of the peritoneum from the overlying abdominal wall is achieved by the effect of an expanding force acting perpendicular to a plane of separation between said peritoneum and said overlying abdominal wall, thereby creating a preperitoneal cavity ; (d) causing the device to contract, and insufflating the preperitoneal cavity with insufflating fluid to create a preperitoneal pneumoperitoneum, thereby creating an operative workspace.

Furthermore, it is another object of the present invention to provide a method for repairing inguinal hernias laparoscopically comprising carrying out previously described steps (a) to (d) , wherein the method further comprises :

(e) making a second traversing incision infra-umbilically, through the anterior rectus sheath, and retracting the rectus abdominis muscles ;

(f) introducing a trocar equipped with a laparoscope via said second incision into the preperitoneal workspace created ; (g) introducing a third trocar into the preperitoneal workspace above the symphisis pubis ; (h) dissecting and reducing the hernia, and placing a repairing prosthetic patch at the site thereof.

Indeed, the approach used in the method for placing the device of the present invention is advantageous in that the separation of the peritoneum by the device from the overlying abdominal wall is easily commenced due to the relatively small thickness of the abdominal wall at the point of first incision, i.e. in the vicinity of the antero-superior iliac crest. Furthermore, the inflatable element of the device substantially corresponds to the anatomically available space in the preperitoneal region, and the intervention can be carried out reproducible and reliably with a significantly reduced number of manipulations, as only one device is involved, thereby reducing the risk of traumatising the peritoneum or the abdominal wall.

These and other objects and advantages of the present invention will be more clearly understood by the following detailed description, with reference to the following annexed drawings.

Description of the Figures Figure 1 represents a longitudinal cross section of a preferred device according to the present invention.

Figure 2 is a schematic representation of the lower thorax and abdomen of the human body, indicating the site of first incision in the method according to the present invention.

Figure 3 represents the same schematic view as Figure 2, after introduction, via the first incision, of the device depicted in Figure 1, and inflation of the inflatable element.

Figure 4 represents the same views as Figures 2 and 3, subsequent to deflation of the inflatable element, insufflation of the preperitoneal cavity, and the making of a second incision through which a second laparoscopic instrument is inserted into the created preperitoneal workspace.

Figure 5 schematically represents the positions of the surgical instruments, after insertion of another trocar into the preperitoneal workspace above the symphysis pubis.

Figure 6 represents a longitudinal cross section of a variant on the preferred device according to the present invention. Figure 7 represents a longitudinal cross-sectional view of yet another variant on the device according to the invention, similar to Figure 1.

Figure 8 represents a transverse cross-sectional 5 view of the device illustrated in Figure 7, along the line VIII-VIII. Preferred Embodiments of the Invention

The device of the invention, as introduced previously, is designed to be used in laparoscopic surgical interventions, and in particular in inguinal hernia repair via the preperitoneal approach, for separating the peritoneum from an overlying abdominal wall.

In a first preferred embodiment, and as shown schematically in the longitudinal cross section of Figure 1, the device comprises at least one rigid longitudinal element 2 of a suitable material, such as plastic, having distal 3 and proximal 4 ends and a throughbore 7, thereby defining a tube with inner 6 and outer 10 walls and a longitudinal axis 5. Preferably the device is provided with a second longitudinal element 2a, mounted inside the throughbore 7 of the first longitudinal element 2, which second longitudinal element 2a is also provided with a second throughbore 7a, inner 6a and outer 10a walls, and second distal 3a and proximal 4a ends, the second distal end 3a extending beyond the first distal end 3 of the first longitudinal element 2.

The preferred device of Figure 1 is also equipped with an inflatable element 8 which tightly surrounds at least a distal part of the outer or inner walls 6, 10 of the longitudinal element. The inflatable element 8 may be made of any suitable material, but preferably of a medical grade material, such as PVC, or rubber. The inflatable element can be made of semi-elastic material, as some stretch is considered desirable in permitting the inflatable element to conform to the space available in the body, or of inelastic material. In any event, the inflatable element should not stretch to the point that damage to the peritoneum or an underlying organ occurs. The inflatable element may be in sealing engagement with the outer or inner walls 6, 10 of the longitudinal element 2. In the case of enagement with the inner wall 6, the inflatable element can be wrapped around an end of the longitudinal element and affixed, such as by gluing, heat sealing, ultrasonic welding or the like, to the inner wall 6. In the particularly preferred embodiment represented in Figure 1, the inflatable element 8 tightly surrounds both the outer wall 10 of the first longitudinal element 2 at a proximal part 9 thereof, and the outer wall 10a of the second longitudinal element 2a at a distal part thereof 9a.

The inflatable element 8 haε subεtantially two configurations, the importance of which will become evident from the following description. As shown in Figure 1, it can adopt a first, flattened deflated configuration for its introduction, having the contour εhown in Figure 1. Thiε flattened configuration effectively allowε for the device to be introduced into a εmall inciεion, aε iε commonly carried out in laparoεcopic εurgery. To ease introduction and εubεequent inflation the inflatable element 8 may be rolled up on either εide of the longitudinal axiε 5, εuch that it unravels inεide the body when inflated with an inflating fluid εuch aε air.

The inflatable element can also adopt a second εubεtantially planar inflated configuration along a median plane which substantially correspondε to the plane of εeparation that exists between the peritoneum and the overlying abdominal wall. The inflation of the inflatable element 8 from the deflated to the inflated state, when placed inεide the preperitoneal region according to the present invention, and aε will be deεcribed more thoroughly further on, provides a separating force perpendicular to and on both sides of the above-mentioned median plane, thereby causing the peritoneum to separate from the overlying abdominal wall, to create a preperitoneal workspace.

Accordingly with similar inflatable elements known from the prior art, the inflatable element 8 is disposed around the longitudinal axis 5, and along said at least longitudinal element 2 over a predetermined distance. However, the inflatable element 8 of the invention differs from those associated with the devices of the prior art in that it has a generally aεymmetrical shape or contour with respect to the general axis 5. This shape iε defined by the element having, on one side of the axis 5, a relatively large and substantially flat surface 13 area, and on the other side of said axis 5, a relatively small and substantially flat surface 15 area, whereby said surface areas 13, 15 correspond to the space available in the body after insertion of the device 1 via an incision 16 made at the anterosuperior iliac crest 17 (cf. Figure 2) . Indeed, the asymmetric shape of the inflatable element of the device according to the present invention enables the surgeon to create a preperitoneal workspace in essentially one separating step, thereby avoiding any need for tunnelling or a εeries of inflating and separating stepε aε known from prior art devices.

The inflatable element is typically 12cm long (along the longitudinal axis 5) , 15cm across and 7cm deep. Thus the inflatable element will generally be sized within the ranges of 8-15cm long, 10-2Ocm across and 5-10cm deep. The inflatable element typically has a relatively small surface area extending 1/5 of the total distance across and a relatively large surface area extending 4/5 of the total distance across, the inflatable element, with the longitudinal axis 5 thereinbetween. Broadly, this proportion of the distance acrosε the inflatable member can vary from 1/10 to 1/3 for the relatively εmall surface area and from 2/3 to 9/10 for the relatively large surface area. The inflatable member when inflated is arcuate in overhead profile, aε εhown in Figure 1. The εhape is roughly in the form of a kidney, or the shape could be described as generally triangular with rounded cornerε.

Inflation of the inflatable element 8 iε achieved by providing inflating meanε 11 which communicate therewith and may be integrated into the device or separate therefrom. The inflating means 11 may comprise any εuitable means which establishes a connection from an inflating fluid source to said inflatable element 8. In the presently preferred embodiment, the inflating meanε compriεeε first tap means 26 disposed in the vicinity of the proximal end 4 of said first longitudinal element 2, said tap means 26 communicating most preferably with the inflatable element 8 via the first throughbore 7. The tap means 26, as repreεented by Figure 1, and in accordance with the preferred embodiment of the invention, is provided with an entry port 27 and an exit port 28, between which is disposed a one way deformable membrane 29, which elastically deforms, under pressure from an external fluid source introduced via the entry port 27, in the direction of the exit port 28, thereby permitting inflating fluid to pasε into the firεt longitudinal element 2, εaid membrane 29 being non deformable in the reverεe direction, thereby preventing εaid insufflated fluid from escaping via the tap means 26.

In addition to the inflation means 11 represented in Figure 1, the device also comprises insufflation meanε Ila, which enable a preperitoneal pneumoperitoneum to be created after the inflatable element 8 has been deflated, by injection of insufflating fluid 20 into the preperitoneal cavity formed thereby. In the preferred embodiment of Figure 1, the insufflation means Ila is also dispoεed in the vicinity of the proximal end 4, 4a of the longitudinal elementε 2, 2a and comprises second tap means 26a, also equipped with entry 27a and exit portε 28a and a one way deformable membrane 29a, as for the inflation means 11. In particular, the insufflation means Ila communicates with the second throughbore 7a of the second longitudinal element 2a, that is to say, the inner of the two longitudinal elements 2, 2a. A preferred variant on the above embodiment may alεo be uεed in accordance with the preεent invention and iε represented by Figure 6. This second preferred embodiment is comprised by the device 1 as esεentially deεcribed above, with the difference that the inflatable element 8 tightly εurrounds the outer wall 10 of only one longitudinal element 2, at distal and proximal parts 9, 9a thereof. The longitudinal element 2 is formed of cylindrical tubing with a hollow interior between its inner and outer walls 6, 10, forming an inflating pasεageway 34, and communicating with the inflatable element 8 via exit means 25, for example through holes or ports, formed in the outer wall 10. The device according to thiε preferred embodiment alεo compriεes introducing means 14 , surrounding the at least one longitudinal element 2, and equipped with insufflation means Ila. It is to be noted that the details concerning the inflation and insufflation means 11, Ila have been omitted in Figure 6 for the sake of clarity, but may be substantially the same as those described for the first preferred embodiment. Figures 7 and 8 schematically represent yet another preferred 20 embodiment of the device according to the present invention. In Figure 7, the device is substantially the same as that in Figure 1, and will therefore only be described in relation to the differences between the two enbodiments. In this embodiment the longitudinal element 2 iε provided with a groove 32 (not shown in Figure 7) on the inner wall 6 extending substantially from the distal end 3 towards the proximal end 4 of the element 2, which groove 32 is designed to fit and retain a corresponding longitudinal rib 33 (not shown) provided on the outer wall 10a of the second longitudinal element 2a, the groove 32 and the rib 33 preventing rotation of the two longitudinal elements 2, 2a when the latter engageε the former. Figure 8 showε a cross-sectional view of Figure 7 along the line VIII-VIII, wherein the groove 32 and rib 33 are clearly visible. The advantage of this particular arrangement is that the surgeon doeε not have to maneuver the inflatable element 8 into the correct poεition, as the outer longitudinal element 2 is prevented from rotating by the cooperation of the groove 32 and the rib 33. Furthermore, the outer longitudinal element 2 comprising the inflatable element 8 can be manufactured so as to be dispoεable, for example by extruεion moulding, while the inner longitudinal element 2a can be a trocar made of metal, and be reεteriliεed. Thiε enableε a εignificant reduction in the complexities and cost of manufacturing of the device, since only one mould iε necessary. It is to be understood that other meanε could be employed to obtain the same end result and are recognisable to the skilled person without further description.

The device according to the present invention may also be provided with other technical features in order to increaεe its usability and field of application. For example, the device may be provided with an opening 23 for the insertion of laparoscopic instruments at the proximal end 4 of the at least one longitudinal element 2 , said opening defining a housing 31 which is cloεed by εealing meanε 12 compriεing a moveable seal 30 dispoεed in the vicinity of the opening 23. The method of uεe of the device, for the creation of a preperitoneal workεpace in inguinal hernia repair 10 will now be explained with reference to Figureε 2 to 5. A device aε previouεly deεcribed is fitted with a laparoscope 19. The longitudinal elements 2, 2a are in the form of a trocar, and the inflatable element 8 in the form of a balloon affixed to the central part of the trocar tube. A first incision 16 is made at the anterosuperior iliac spine 17, homolateral to the hernial site. The preperitoneal region is directly engaged and separation commenced by insertion of the surgeon's finger. The device is inεerted horizontally, the trocar oriented εo as to ensure that the inflatable element will expand more in the direction of the opposite facing iliac spine, i.e. the larger surface area part 13 of the balloon is placed facing towardε the umbilicus 18. The separation of the peritoneum is carried out with the aid of the laparoεcope 19, by inflation of the inflatable element 8, which is deployed towardε said umbilicus and the epigastric vesεelε (cf. Figure 3) . The inflatable element or balloon 8 iε thereafter deflated and can be left in place. The space thus formed is maintained artificially by insufflation of carbon dioxide gaε. A second horizontal incision 20 is then made two centimeters underneath the umbilicus 18, the anterior εheath of the rectus muscleε incised transversely, and retracted laterally. A second trocar 21 is inserted in this incision 20 and the laparoscope 19 inserted therein (cf. Figure 4) . Following that, a third trocar iε introduced at about 4 to 5 centimetres above the pubis enabling nearer acceεε to the hernial site and permitting the insertion of other instruments (cf. Figure 5) . The hernial repair is thereafter carried out by known procedure, usually involving the placing and stapling of a prosthetic patch at the hernial site after diεεection and reduction of the hernial sac.

Claims

1. A laparoεcopic surgical separating device (1) for separating the peritoneum from the overlying abdominal wall to permit accesε to a preperitoneal operative εite for uεe in preperitoneal laparoscopic inguinal hernia repair, said device comprising at least one relatively rigid longitudinal element (2) having first distal (3) and proximal (4) endε, a longitudinal axiε (5) , an exterior wall (10) and an interior wall (6) defining at leaεt one throughbore (7) ; an inflatable element (8) in sealing engagement with at least a distal part of the exterior (10) or interior (6) wall of the at leaεt one longitudinal element (2) ; inflating means (11) communicating with the inflatable element (8) for inflating the inflatable element ; the inflatable (8) element having a first, flattened deflated configuration suitable for insertion into the preperitoneal region, and a second, subεtantially planar inflated configuration along a median plane for providing a εeparating force perpendicular to the median plane when the inflatable element iε inflated in the preperitoneal region to εeparate the peritoneum and the overlying abdominal wall to create a preperitoneal workspace, characterized in that the inflatable element (8) is disposed around a portion of the longitudinal axis (5) and along said at least one longitudinal element (2) over a predetermined diεtance, and haε a generally asymmetrical shape such that the inflatable element (8) has a relatively large and subεtantially flat εurface (13) area on one εide of the longitudinal axiε (5) and a relatively εmall εubεtantially flat εurface area (15) on the other εide of the longitudinal axis (5) , the said surface areas (13,15) correspond to the εpace available in the body after insertion of the device (1) through an incision made at the antero-superior iliac crest (17) .

2. The device (1) of claim 1, wherein a second relatively rigid longitudinal element (2a) is mounted inside the throughbore (7) of the first longitudinal element (2) , the second longitudinal element (2a) having second diεtal (3a) and proximal (4a) ends and interior and outer (10a) walls, the interior wall (6a) defining a second throughbore (7a) , the second distal (3a) end extending beyond the firεt distal end (3) of the first longitudinal element (2) , the inflatable element (8) being in sealing engagement with a proximal part (9) of the outer (9a) wall (10) of the first longitudinal element (2) and a distal part (9a) of the outer wall (10a) of the second longitudinal element (2a) .

3. The device (1) of claim 2, further including insufflation means (Ila) for passing an insufflating fluid through a throughbore, the inflating means (11) and the insufflating means (Ila) being disposed in the vicinity of the proximal (4) end of the first longitudinal element (2) , the inflating means (11) comprising a first tap meanε (26) and the inεufflation meanε comprising a second tap means (26a) .

4. The device (1) of claim 2, wherein the inflating means (11) communicates with the inflatable element (8) via the first throughbore (7) , and the insufflation means (Ila) communicates with the second throughbore (7a) .

5. The device (1) of claim 4, wherein the firεt (26) and second (26a) tap meanε each include an entry port (27,27a) and an exit port (28,28a) between which a one way deformable membrane (29,29a) is dispoεed, said membrane elastically deforming, under presεure from an external fluid source introduced via the entry port (27,27a), in the direction of the exit port (28,28a) to permit inflating and insufflating fluid reεpectively to paεε into the reεpective firεt (2) and second (2a) longitudinal elementε, εaid membraneε (29,29a) being non deformable in the reverse direction to prevent the insufflating fluid from escaping via the tap devices.

6. The device (1) of claim 1, wherein the inflatable element (8) iε in sealing engagement with the outer wall (10) of the longitudinal element (2) at diεtal (9) and proximate (9a) partε thereof.

7. The device (1) of claim 1, wherein the at leaεt one longitudinal element (2) iε formed of a cylindrical tube having a hollow interior forming an inflating paεsageway (34) between itε exterior (10) and interior (6) wallε, the inflating pasεageway (34) communicating with the inflating element (8) via exit means (25) formed in the exterior wall.

8. The device (1) of claim 1, further including an opening for the insertion of laparoscopic instrumentε, εaid opening (23) located at the proximal end (4) of the at leaεt one longitudinal element (2) , the opening (23) defining a houεing (31) , and moveable seal means dispoεed in the vicinity of the opening for εealing the houεing.

9. The device (1) of claim 1, further including passage (34) means surrounding a portion of the at least one longitudinal element (2,2a) for passing insufflation fluid therethrough, said passage means (34) being operatively associated with the insufflation means (11) .

10. The device (1) of claim 2, wherein the relatively rigid longitudinal element (2) has a longitudinal throughbore (7) , an inflatable element (8) in sealing engagement with the outer wall (10) of the longitudinal element (2) at both a distal (9) and proximate (9a) part thereof, the longitudinal element (2) being provided with a longitudinal groove (32) on its inner wall (6) , said groove (32) extending substantially from the distal end (3) towards the proximal end (4) of the longitudinal element (2) , a mating longitudinal rib (33) provided on the outer wall (10a) of the second longitudinal element (2a) , the groove (32) and the rib (33) cooperating to prevent relative rotation of the first (2) and second longitudinal (2a) elements when the rib (33) engages the groove (32) .

11. A laparoscopic surgical separating device (1) for separating the peritoneum from the overlying abdominal wall to permit accesε to a preperitoneal operative εite for uεe in preperitoneal laparoεcopic inguinal hernia repair, εaid device (1) compriεing at least one relatively rigid longitudinal element (2) having first distal (3) and proximal (4) ends, a longitudinal axis (5) , an exterior wall (10) and an interior (6) wall defining at least one throughbore (7) ; inflatable element (8) means dispoεed around the longitudinal axis (5) and along the at least one longitudinal element (2) over a predetermined distance for changing in shape from a first, flattened deflated configuration, which permits the insertion of the device (1) through an incision to enter the preperitoneal region, to a second, subεtantially planar inflated configuration having a medial plane to provide a separating force perpendicular to the medial plane during inflation to cause separation of the peritoneum and the overlying abdominal wall to create a preperitoneal operating workspace, the inflatable element means (8) having a generally asymmetrical shape with a relatively large and substantially flat surface area (13) means on one side of the axis and a relatively small substantially flat surface area (15) means on the opposite side of the axis, said surface area (13,15) means for εubstantially filling the space available in the body of a patient after insertion of the device (1) through an incision made at the antero-superior iliac crest (17) and for exerting said separating force to εeparate the peritoneum and the overlying abdominal wall ; and inflating meanε (11) communicating with the inflatable element (8) for inflating the inflatable element (8) .

12. A method for εeparating the peritoneum from an overlying abdominal wall of a patient to create a preperitoneal workεpace permitting acceεε to a preperitoneal operative εite, compriεing ; a) making a first traversing incision in the abdominal wall of the patient as far as the anterior surface of the peritoneum, in the vicinity of an antero-superior iliac creεt, homolateral to the hernia to be repaired ; b) introducing a εeparating device generally horizontally into the inciεion to enter the preperitoneal region ; c) expanding the introduced separating device, with the expansion being greater towards the opposite facing side of the body than toward the side of the introduction, to εeparate the peritoneum from the overlying abdominal wall by the effect of an expanding force acting perpendicular to a plane of εeparation between the peritoneum and the overlying abdominal wall, to create a preperitoneal cavity ; contracting the introduced εeparating device, and insufflating the preperitoneal cavity with insufflating fluid to create a preperitoneal pneumoperitoneum, thereby creating an operative workspace.

13. Method of claim 12, wherein the method is a method of laparoscopically repairing an inguinal hernia, the method further compriεing the εteps e) making a second traversing incision infraumbilically, through the anterior rectus sheath, and retracting the rectus abdominis muεcles ; f) introducing a trocar equipped with a laparoscope through the second incision into the preperitoneal operative workspace ; g) introducing a third trocar into the preperitoneal operative workεpace above the symphysis pubis; and h) dissecting and reducing the hernia, and placing a repairing prosthetic patch at the hernia site.