Hernia (2003) 7: 210–214 DOI 10.1007/s10029-003-0154-9

A PP L IE D AN A T OM Y

O. P. Sudrania Æ R. K. Agrawal Æ Samar Deb A. K. Khanna

Pubomyoaponeurotic foramen and posterior groin plait for groin hernia

Received: 8 July 2002 / Accepted: 23 April 2003 / Published online: 16 August 2003 Ó Springer-Verlag 2003

Abstract Sir Astley Paston Cooper stated in 1804 that a sound knowledge of proper anatomy of hernia is vital. But even in the succeeding two centuries, the confusion has only multiplied by varied and overly enthusiastic descriptions, some speculative and others real, by different workers. An attempt has been made to highlight the size of the controversies surrounding the anatomical structures forming the inguinal canal and groin. The inguinal and femoral hernias should be viewed collectively as one entity and together be called groin hernias. Therefore, the passage for their superficial emergence through the anterior abdominal wall is redefined and is called pubomyoaponeurotic foramen. It is uniformly accepted that the strong posterior wall of the groin area is the only preventive factor towards the emergence of hernia; it has been renamed as posterior groin plait. Therefore, proper understanding of its structure towards effective repair and reinforcement is the only safe method, whether the procedure is carried out by anterior or posterior route or laparoscopically. Hence, an attempt has been made to elucidate its true structure. In spite of so many descriptions, the exact anatomy of hernia is yet to be resolved.

O. P. Sudrania S3 BIMAS Research Academy, 201 Laxmi Building J. B. Nagar, 400 059 Mumbai, India R. K. Agrawal Sunrise Nursing Home, Siliguri, India S. Deb Department of Anatomy, Vice Principal NBMC & Hospital, Sushrutnagar, India A. K. Khanna (&) Department of Surgery, Institute of Medical Sciences Banaras Hindu University, 221005, Varanasi, India E-mail: [email protected] Tel.: +91 542 2318418 Fax: +91 542 2367568

Keywords Anatomy Æ Surgical Æ Laparoscopic Æ Repair Æ Inguinal Æ Femoral

Introduction An attempt is made to stimulate fresh interest in the conventional surgical anatomy of the groin area toward better understanding and execution of the desired surgical techniques for its repair, be it open or laparoscopic, as the outcome of hernia surgery is highly dependent on the surgeon [1] rather than on the individual technique or the kind of material used. This is important while considering the repairs of all the hernias in this area, which are a complex and a multifactorial problem, with the possible exception of congenital inguinal or simple femoral hernias. This discussion is not intended as an exhaustive review of the subtleties of the anatomical disposition and descriptions of the groin, which are so complex and have been a conjectural issue from times immemorial. A lot of terminologies are conventionally used and empirically stressed, e.g., conjoint tendon, lacunar ligament, fascia transversalis, and its so-called analogues, e.g., iliopubic tract, interfoveolar ligaments, the internal inguinal ring, and so on, whose existence has never been challenged nor appears to have been examined critically and analytically so far.

Brief scan of controversies As stated by Sir Astley Paston Cooper (1804), ‘‘No disease of the human body, belonging to the province of the surgeon, requires in its treatment a better combination of accurate anatomical knowledge with surgical skill than hernia in all its varieties’’. It is amazing that even after this statement by Cooper about two centuries ago, the mystery still exists, and controversy reigns supreme about the anatomical knowledge of the groin area. Seymour Schwartz (1994)

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is reiterating the same rhetoric even now [2]. No wonder we have been still struggling to improve upon our results of the repair of hernias. As Nyhus and Bombeck [3] remarked, ‘‘The last chapter on the history of groin anatomy and operative repair of hernia defects has not been written’’. Condon [4] states, ‘‘The iliopubic tract is the lower border of the transversus abdominis layer of muscle and aponeurosis. The hernial defect, in both indirect and direct varieties of groin hernia, is found within the transversus abdominis layer. It is within this layer that repair of the hernial defect is constructed’’. He calls his technique the anterior iliopubic tract repair.’’ But the purists maintain that the iliopubic tract is a posterior structure, not accessible and visible from the anterior aspect. Griffith [5], in describing ‘‘The Marcy Repair of Indirect Inguinal Hernial 1870 to the Present’’, states to the contrary—the transversalis and iliac components of endoabdominal fascia in the groin exist alone and separate from their intrinsic muscles (the transversus abdominis and iliopsoas). But he also believes that the iliopubic tract exists, and he states further, ‘‘Transversalis fascia (the site of inguinal hernia) and iliac fascia (the site of femoral hernia) fuse to form the dense iliopubic tract. The fallacy expressed by some that the iliopubic tract does not exist stems from the fact that it lies hidden from view beneath the inguinal ligament and can be exposed only by retracting the ligament’’. The preceding statements by two noted herniorrhaphists are sufficiently contrary to each other regarding the origin of iliopubic tract, as well as the nature of the posterior inguinal wall. Raymond Read [6], having the experience of preperitoneal exposure of groin herniae, from both the anterior and posterior approach, has demonstrated a posterior lamina deep to the epigastric vasculature attached to the pubic ramus. Repair of the inguinal hernias should begin in the preperitoneal layer internal to the Astley Cooper’s bilaminar transversalis fascia and the epigastric vessels. Colborn and Skandalakis also have accepted the two-layer concepts of Cooper’s fascia transversalis. Even they talk of the third layer in the same paper. However, they also warn, ‘‘It can not yet be said that this mild debate is over, as to whether the transversalis fascia is bilaminar or whether the ‘posterior lamina’ is simply a significant regional condensation of extraperitoneal connective tissue’’ [7]. Bailey and Love [8], as well as Last [9], do not at all believe in the existence of the iliopubic tract and feel that the posterior wall of inguinal canal is formed only by fascia transversalis and conjoined tendon (medially). But again Condon [10] contests the existence of true conjoined tendon. He found it in only 3% of bodies in his dissections. He also doubts the existence of lacunar ligament (Gimbernat’s ligament). He found its true existence in only eight out of 185 bodies. He also states that the medial boundary of femoral ring was not formed by the edge of the lacunar ligament in the

majority. ‘‘In only eight out of 94 dissections did the most lateral part of the insertion of the lacunar ligament actually touch the medial border of the distended femoral canal; ... ’’ Nyhus [11] also observes, ‘‘The importance of the transversalis fascia and the internal abdominal ring in the repair of groin hernias has been recognised by many authors. The role of the iliopubic tract in these matters, however, is obscure’’. He also quotes Polya, ‘‘Polya made several interesting comments concerning this structure (the iliopubic tract): ‘The opinions are not unanimous whether this ligament is part of the transversalis fascia, Pouparts’ ligament, femoral sheath or the psoas fascia.’ As far as I am concerned, and most of the other authors agree, this ligament constitutes a part of the transversalis fascia’’. However, Nyhus himself states further about the posterior inguinal wall or the deep musculoaponeurotic lamina, as he calls it, composed of the transversalis fascia and its analogues. e.g.. iliopubic tract, crura, and sling of the internal ring, transversus abdominis aponeurosis, proximal femoral sheath, and Cooper’s ligament. The floor of the inguinal canal is primarily formed by the bony superior ramus of the pubis and its closely associated structures: the pectineus muscle, the pectineus fascia, and the more distal portion of the anterior femoral sheath. This description, although it appears rather bizarre, is interesting and intrepid. He is a proponent of the preperitoneal approach through anterior route and posterior iliopubic tract repair. These descriptions, however, are a gross deviation from the traditional belief that the floor of the inguinal canal has been described to be formed by the inguinal ligament irrefutably. At the same time, the inguinal ligament has been regarded as an undisputed borderline between the abdomen and thigh, as well as the inguinal and femoral compartments. Most interesting of all are the observations of Rutledge [12]. He is an advocate of the Cooper ligament repair of the groin hernias earlier popularized by Chester McVay in the early part of this century. He, while describing the ‘‘Anatomic Basis for a Cooper Ligament Repair’’ states, ‘‘A strong posterior inguinal wall is the best protection against a groin hernia in an adult. Normally, this is provided by the insertion of the transversus abdominis and the underlying transversalis fascia from the pubic tubercle to the medial margin of the femoral ring. There is a wide variation in the length of the insertion of the transversus abdominis on the Cooper’s ligament. In about 75% of McVay’s dissections, this was a long insertion with broad aponeurotic plate, giving a strong posterior wall. These people are unlikely to develop a direct hernia. In the remaining 25%, the insertion was short, and the continuity of the posterior wall was made up only of the transversalis fascia, making the wall potentially much weaker [13]. This weak area of the posterior wall that is protected only by the transversalis fascia has been called the myopectineal orifice by Fruchaud’’ [14].

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These observations of Rutledge are highly significant, which highlights both the controversies, as well as the crux, of the anatomy. He quotes both McVay as well as Fruchaud in the same breath, whose descriptions point towards the similar solution in a little different way on a closer analytical examination. But it has neither been fully grasped by the French nor by the English School of workers. One example is the description of visceral sac repair of Rene Stoppa, so well known as GPRVS, even as late as 1994 [15].

Pubomyoaponeurotic foramen Therefore, a more composite and a definitive approach to the concept of the weakness in the groin area has been suggested in the name and shape of the pubomyoaponeurotic foramen (Fig. 1 and Fig. 2). The pubomyoaponeurotic foramen appears to be more scientific, appropriate, and exact with the specific tissues involved in the groin. It is the body and superior ramus of pubis bone involved as a whole, and a lot of the aponeurotic structures play an important role besides the muscles of the area. The word foramen seems more apropos anatomically and literally. Thus the name pubomyoaponeurotic foramen and its dimensions are as follows: 1. Medially: Rectus muscle and its tendon, the conjoined part of its anterior sheath, pubic tubercle, lacunar ligament, if it exists 2. Laterally: Iliopsoas muscles, the strong fascia covering it (fascia iliaca), the adjoining pelvic brim (part of

Fig. 2 Posterior view of pubomyoaponeurotic foramen. 1 Anterior Superior Iliac Spine; 2 Inguinal Ligament; 3 Ilio—Psoas muscle; 4 Lateral cutaneous N. Of thigh; 5 Genito—Femoral N.; 6 Cut Iliac bone; 7 Superior Ramus of Pubis; 8 Pubomyoaponeurotic Foramen; 9 Transversus abdominis muscle; 10 Deep inguinal ring with spermatic cord; 11 Linea Semilunaris; 12 Rectus Muscle; 13 Inferior epigastric Vessels; 14 Arcuate line of Douglas; 15 External Iliac vessels; 16 Obturator foremen; 17 Iliac part of pelvic brim; 18 Public tubercle and crest

3. 4. 5.

6.

Fig. 1 Anterior view of pubomyoaponeurotic foramen. 1 Anterior Superior Iliac Spine; 2 Inguinal Ligament; 3 Ilio-Psoas muscles; 4 Femoral nerve; 5 Pectineus Muscle & Fascia; 6 Pubomyoaponeurotic foramen; 7 Pubic Tubercle & crest; 8 Linea Semilunaris; 9 Rectus Muscle; 10 Internal Oblique Muscle; 11 Arch of Internal Oblique & transversus Abdominis muscle; 12 Acetabulum; 13 Obturator Foramen; 14 Conjoined area; 15 Superior Ramus of Pubis; 16 Deep Inguinal ring

iliac bone), genitofemoral nerve, lateral cutaneous nerve of thigh Superiorly: ‘‘Triple layer’’ arch formed by transversus abdominis muscle, internal oblique muscle, fascia transversalis Inferiorly: Superior ramus of pubis with its pectineal ridge and posterior surface, Cooper’s iliopectineal ligament, pectineus fascia and muscle Posteriorly: Posterior groin plait, internal (deep) inguinal ring, retroperitoneal areolar tissue, urachal fold/median umbilical ligament (urachus), umbilical fold/medial umbilical ligament (obliterated umbilical artery), inferior epigastric folds/lateral umbilical ligament (deep inferior epigastric vessels), peritoneum Anteriorly: Aponeurosis of external oblique muscle, external (superficial) inguinal ring, fascia of scarpa and camper, skin

The inguinal ligament may be seen as bisecting this foramen into the inguinal compartment above and femoral below. The inguinal compartment is traversed by the spermatic cord, ilioinguinal nerve, and genital branch of genitofemoral nerve. The femoral compartment is traversed by external iliac/femoral vessels, femoral branch of the genitofemoral nerve. The various neighbouring areas are of great surgical importance, especially during laparoscopic surgery. A very vivid and lucid description of the Triangles of Doom and Pain, as well as Bendavid’s Circle of Death, along with beautiful coloured plates are provided by Colborn and Skandalakis [7].

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Posterior groin plait It may be recalled that the fascia transversalis is a very thin filmy transparent membranous structure spread over most of the abdominal cavity, including the groin area. Hence, the fascia transversalis alone confers no immunity against the powerful offending forces favouring herniation. Therefore, the importance of the strong posterior wall of the groin is also stressed and to give sufficient importance and respect to it, a distinct name viz. posterior groin plait is suggested. The word plait denotes something interwined, interwoven, braided, or pleated, and it seems to be the most befitting expression of its true structure. It contains fibers from every tissue in its vicinity. The fact that fascia transversalis contributes very little to its formation nor to its strength, should also be fully appreciated. The posterior groin plait consists of contributions from the following structures: arch of the transversus abdominis, edge of the inguinal ligament, iliopubic tract, fascia transversalis, conjoined area/tendon, rectus sheath, interfoveolar ligament, ligament of Henle, falx inguinalis, Cooper’s ligament, periosteum of superior ramus of pubis, fascia of pectineus muscle, crura of deep inguinal ring, deep inguinal ring (situated in it at its lateral end). Its attachments are as follows: 1. Below: Inguinal ligament, iliopubic tract, Cooper’s ligament, superior ramus of pubis and its posterior surface 2. Above and laterally: Attached and firmly blended with triple layer arch 3. Medially: Attached to the structures forming the medial boundary of pubomyoaponeurotic foramen

Importance of surgical anatomy in laparoscopic procedures Surgical anatomy in Transabdoiminal preperitoneal repair (TAPP) There is an ill-defined midline fold raised by the urachus. Some call it median umbilical ligament, and others call it medial umbilical ligament. It may be called urachal fold to avoid confusion. Some call another fold raised by the obliterated umbilical arteries medial umbilical ligament, whereas others call it lateral umbilical ligament. This may be simply termed umbilical fold to avoid confusion. A third lateral most peritoneal fold raised by the inferior epigastric vessels is called lateral umbilical ligament by some, while others call it inguinal or epigastric fold. It is suggested to call it inferior epigastric fold. Most of the time, it is poorly raised and difficult to recognize. Lateral to the inferior epigastric fold lies the internal ring—site of indirect inguinal hernia—whereas direct inguinal hernias occur between this and the umbilical fold usually. One can also see the pulsations of the external

iliac vessels in the vicinity, and just medial to and in the same plane lies the femoral ring—the site for femoral herniation. In the event of difficulty or confusion, the external iliac vessels can also serve as a good landmark to start to build the anatomical landmarks of the area. The important thing here to remember is that in TAPP repair, we incise and reflect a fold of peritoneum alone, and the preperitoneal fat along with the fascia transversalis is left behind with the anterior abdominal wall or the posterior aspect of the groin. This is in contrast to the dissection in total extraperitoneal repair (TEP) in which all these three layers will be dissected away from the anterior parities on the posterior aspect of the posterior aspect of the groin. Total extraperitoneal repair (TEP) It is important here to recollect the exact anatomy of the anterior abdominal wall from umbilicus down to the groin areas. The two recti muscles lie closely, edge to edge, with each other except for a centimeter or two, just below the umbilicus. The posterior rectus sheaths on either side are absent from midway between umbilicus and pubic symphysis. The transition line is called the semicircular fold of Douglas. The semicircular fold of Douglas may be a sharp transition, or, more often, the transition of posterior sheath anteriorly may not be sharp and smooth. This results in several semicircular lines, and it may create difficulty during dissection and development of various tissue planes in the early stages when the procedure is mostly blind. The inferior epigastric vessels may lie between the fascia transversalis and the transversus abdominis muscle, or it may lie in the preperitoneal plane. In a later event, it pierces the fascia transversalis at a variable level below the semicircular fold to enter the rectus sheath. This fact should also be borne in mind while developing the space to avoid any mishap. It may be difficult to locate the landmarks in the tissue planes. In such events, external pressure with a finger over or nearby some defined spots, e.g., pubic tubercle, above the femoral vessels; medial to anterior superior iliac spine may help tremendously. After the skin, subcutaneous tissues, and anterior rectus sheath are incised, the muscle bundles of recti muscles are separated by blunt dissection to approach the plane between the posterior rectus sheath and the rectus muscle till the level of the semicircular fold. Distal to that, the fascia transversalis along with the peritoneum and the peritoneal fatty tissue are lifted away from the transversus abdominis muscle.

Inadvertent attempts at the repair of pubomyoaponeurotic foramen This is positively exemplified by the surgeons and herniorrhaphists who practice Cooper’s ligament repair technique. One finds, on closer examination, that repair of Cooper’s ligament technique is, in essence, repair of the pubomyoaponeurotic foramen. We reproduce briefly

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from the descriptions of Chester McVay [16] himself: ‘‘After making the relaxing incision, the strong cut edge of the transversus abdominis aponeurosis is sutured to Cooper’s ligament from the pubic tubercle to within a few millimeters of the external iliac vein. This maneuver not only reconstructs the posterior inguinal, but it reestablishes a normally broad insertion into Cooper’s ligament and thus obviates the possibility of a femoral hernia’’.

Conclusion Results of hernia surgery in particular, are highly surgeon-dependent, irrespective of the technique or material used. A good knowledge of the surgical anatomy forms an integral part of the repair. It is universally and uniformly accepted that a strong posterior wall viz. posterior groin plait is the only way of preventing the occurrence of all the hernias in the groin—be it inguinal or femoral. Hence, they could be called more conveniently and collectively as groin hernias together and should be viewed as one single entity emerging out through the pubomyoaponeurotic foramen. It is now being increasingly recognized that failure to appreciate this fundamental factor has led to some earlier disappointments in the repair of this area in the past and, more recently, in laparoscopic repair, which is now practiced more and more frequently. We have attempted to define clearly the structure of posterior groin plait and also the boundaries of the pubomyoaponeurotic foramen. Therefore, it is stressed that appreciation of this vital anatomical detail is highly important, and a need for a strong awareness is recommended.

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