Out Most of Itslength to the Iliopectineal Line,Has an Outer

Home , Femoral canal, Femoral ring, Saphenous opening

FEMORAL HERNIA Lecture delivered at the Royal College of Surgeons of England on 12th October 1956 by W. J. Lytle, F.R.C.S. Lecturer in Surgery, University of Sheffield FOR A FEMORAL hernia to exist it must pass through two openings. The upper is the femoral or crural ring which normally is wide open and lies at the level of the iliopectineal line at the upper end of the femoral canal. The lower opening, which I shall name the femoral hernial orifice, is one of new formation where the hernia has broken through a barrier at the lower end of the femoral canal. These openings, the femoral ring and the femoral hernial orifice, are not one and the same opening but are distant from each other. The accepted teaching is that the curved edge of Gimbernat's ligament forms the inner boundary of the femoral ring and lies at the upper end of the femoral canal. This paper seeks to prove that the curved edge of Gimbernat's ligament lies at or near the lower end of the femoral canal and forms the inner boundary of the femoral hernial orifice. It will be shown that this ligament which has also been named the lacunar ligament and the pectineal part of the inguinal ligament, although attached through- out most of its length to the iliopectineal line, has an outer curved margin which is slung to the pectineal fascia well below this line. Another and separate ligament, the ligament of Henle, lies at the upper end of the femoral canal and it is the curved edge of this almost unknown ligament which bounds the inner margin of the femoral ring. Figure 1, which is a photograph of the femoral region after the hernial sac has been removed, shows the large oval saphenous opening or fossa ovalis, with the pectineal fascia forming its floor. The femoral hernial orifice is seen in the upper and outer corner of the saphenous opening, lying behind the superior cornu, with the curved edge of Gimbernat's ligament covered by the fascia of Scarpa on its inner side. The inguinal ligament and the femoral vein, usually shown in drawings of this region, are not in view. The barrier at the lower end of the femoral canal, through which a femoral hernia breaks to form the femoral hernial orifice, arises in the following manner: the fascial layers of the anterior abdominal wall, taking the external oblique aponeurosis as one of these layers, are con- tinued down in the same plane over the femoral vessels as the anterior wall of the femoral sheath. These layers are the fascia of Scarpa, the fascia lata which is the prolongation downwards of the external oblique aponeurosis, and the fascia transversalis. On the inner side of the femoral vein there lies a large triangular space between the inguinal ligament and 244 FEMORAL HERNIA the pectineal fascia. This space is sealed off by a backward turn of these three fascial layers which are attached posteriorly to the pectineal fascia and iliopectineal line (Fig. 7). This backward turn, which provides a partition or barrier on the inner side of the femoral sheath, takes place in such an unobtrusive way that its significance has been overlooked by surgeons and anatomists. It is at the outer side of this femoral partition,

Fig. 1. Photograph of the saphenous opening showing the femoral hernial orifice. where it joins the medial wall of the femoral sheath that the hernial sac breaks through to form the femoral hernial orifice. The fascia of Scarpa and the saphenous opening A wide exposure when operating for femoral hernia (Figs. 1 and 2) shows that the fascia of Scarpa, usually referred to as the membranous layer of the superficial*fascia of the abdomen, passes down over the inguinal ligament and continues on as the superficial layer of the femoral sheath. It is usually taught that the fascia of Scarpa ends just below the inguinal ligament by blending with the fascia lata, but in this paper the femoral sheathwill be described as having three layers in its wall: the fascia of Scarpa, the fascia lata and the transversalis fascia. The fascia of Scarpa and the fascia lata are usually closely fused together. The fascia of Scarpa thus lies as a blanket over the femoral region covering and concealing its familiar landmarks: the inguinal ligament, the pubic spine and the femoral vein. It should be stated that there is another or deeper layer of fascia on fie abdominal wall which lies beneath Scarpa's fascia in close contact with 245 W. J. LYTLE the external oblique aponeurosis. This layer, when divided and brushed aside, reveals the shining aponeurosis of the external oblique muscle with its intercolumnar fibres. This deep and rather thin layer, which has been given the unusual title, the innominate or unnamed fascia (Gallaudet, 1931), fuses below with the overlying fascia of Scarpa, where both layers are attached to the whole length of the inguinal ligament. The innominate fascia is probably incorporated with the fascia of Scarpa in the thigh. The folds and attachments of the fascia of Scarpa below the inguinal ligament give this region its distinctive appearance. The margins of an obliquely inverted U stand out prominently as the boundaries of the saphenous opening or fossa ovalis which enclose the oval-shaped floor of pectineal fascia (Figs. 1 and 2). To display the saphenous opening, which measures about 12l2in. long by 1 in. broad, it is necessary to make a long incision and to dissect the superficial fat and lymphatics from the femoral sheath and pectineal fascia. The saphenous opening, as seen in the living body, differs in some respects from that found in the dissecting room. The femoral sheath has three layers in its wall: the fascia of Scarpa, the fascia lata and the transversalis fascia (Fig, 3). In the living body the filled femoral vein has a lumen of about 15 cm. in diameter, several times the capacity of the

MEMBRANOUS LAYER OF. THE SUPERFICIAL FASCIA (SCARPA'S FASCl& COtN OF PEMORPALS :ePECTINIAL4|2 FEMORAL~~~~~~~~~~IGINAL~~~~~~~~~(IBERNAT'SLIGAMENTLIGAMENT) HERNIAL.. HERNIAL COVERED BY MEMBRANOUS - ORIPICE AYER. l l |OF THE SUPERFICIAL IA ISCARPAS PASCIA)

ANTERIOR WALL 0 FEMORAL SHEATH PUBIC SPINE

MEDIAL WALL OF FAScl FEMORAL SHEATHl PECTINEAt. (CRIBRIFqRM FASCIA

FALCIFOR1 MARGIN

Fig. 2. The saphenous opening: a drawing of Fig. 1. femoral artery. To accommodate this large filled vein, the sheath, instead of lying flat as it does on the collapsed vein of the cadaver, stands high above the pectineal fascia and presents an inner wall 112 to 2 cm. in depth in addition to its anterior wall. Between the inner and anterior surfaces of the femoral sheath lies a prominent border which corresponds to the falciform margin or process of the flat saphenous opening of traditional 246 FEMORAL HERNIA anatomy. Although the inner wall of the femoral sheath has three layers of fascia in its substance, it is much thinner than the anterior wall and corresponds to the forward looking cribriform fascia of the saphenous opening of the dissecting room. The inner wall or area covered by the cribriform fascia is often wrongly referred to as the saphenous opening itself. On the inner side of the femoral sheath, Scarpa's fascia turns at right angles over the inguinal ligament to form the outer covering of the triangular area between the inguinal ligament and pectineal fascia, and then fuses with the latter. Gimbernat's ligament lies beneath the fascia of Scarpa in this triangular area and its outer curved edge forms the inner boundary of the hernial orifice (Fig. 1). In front of this area the fascia of Scarpa, as it turns over the inguinal ligament, forms a fold which is the superior cornu of the saphenous opening. Still further towards the middle line of the body, the fascia of Scarpa runs downwards and inwards over the inner end of the inguinal ligament, pubic spine or tubercle, and the spermatic cord. Below these, the fascia of Scarpa fuses with the pectineal and adductor fascia along a junction line which runs downwards and inwards from the superior cornu of the saphenous opzning towards the perineum. This attachment limits extra- vasation of urine and prevents the cord from wandering into the thigh. The junction line of the fascia of Scarpa and the adductor and pectineal fascia is clearly visible, and when followed upwards and outwards joins the superior cornu of the saphenous opening and then turns down as the prominent edge of the femoral sheath (falciform margin or process). In this manner an obliquely inverted U is displayed whose margins form the boundaries of the saphenous opening or fossa ovalis. The inferior cornu of the saphenous opening lies on a deeper plane and its crescentic edge, composed of the fascia lata covering the ilio-psoas and pectineus muscle, lies under and is usually concealed by the saphenous vein which itself is covered by fascia and is not in view (Fig. 3). It is of interest also to note that a superficial layer of fascia branches off from Scarpa's fascia a centimetre or more above the inguinal ligament, to continue on as the deep layer of the superficial fascia of the thigh (Fig. 7). This superficial layer sends a septum of fascia backwards 112 in. below the inguinal ligament to join the femoral sheath and pectineal fascia along the line of the flexion skin crease of the groin (Holden's line). This septum, passing backwards, gives support to the superficial branches of the femoral vessels as they pass up to the genitals and superficial tissues of the abdominal wall. An oval or egg shaped box of fascia is thus formed between this superficial layer and the pectineal fascia, which can be demonstrated at operations. This oval space contains and directs upwards the enlarging sac of a femoral hernia. The swelling in the groin, due to a 247 W. J. LYTLE femoral hernia, lies between Holden's line or groin crease and the line of the inguinal ligament, and as it enlarges passes up over the latter. Femoral hernial orifice When the surgeon, operating through an incision in the groin, has removed the sac of a femoral hernia and replaced the stump within the abdomen, he sees a circular opening in the fascia of Scarpa. The edges of

LINE OF INGUINAL LIGAMENT MEMBRANOUS LAYER (POUPART S LIGAMENT) OF SUPERFICIAL FASCIA PECTINEAL PART OF THE (SCARPA'S FASCIA) INGUINAL LIGAMENT. _GIMBERNAT'5 LIGAMENT) COVERED BY SCARPA!S FASCIA TRANSVERSALIS FASCIA -- SUPERIOR CORNU

...---- PUBIC SPINE SCARPA'S FASCIA BLENDED WITH - FASCIA LATA MEDIAL WALL OF FEMORAL SHEATH

FASCIA OVER _ t ILIO-PSOAS M,i FASCIA

--INFERIOR CORNU

LONG SAPHENOUS'l '

Fig. 3. The femoral sheath. The anterior wall has been removed leaving the medial wall in situ. this opening fall together to form an oblique fascial slit, and in the photograph of this region these edges are held apart by a hidden glass tube (Fig. 1). This is the orifice or port of exit of a femoral hernia, and the opening of new formation is surrounded by three layers of fascia: the fascia of Scarpa, the fascia lata layer which includes Gimbernat's ligament, and the transversalis fascia (Fig. 7). The opening lies obliquely behind the superior cornu of the saphenous opening and faces downwards and inwards. The orifice is usually shown to be four sided and to have as its boundaries the inguinal ligament, Gimbernat's ligament, the femoral vein and the pectineal fascia; yet it is more accurate to say that it is a circular opening surrounded by the fascial layers of this region and placed within these four boundaries. The opening does, however, usually encroach on 248 FEMORAL HERNIA the pectineal fascia. The usual textbook drawing is misleading, for of the four boundaries commonly shown by the artist only one, the pectineal fascia, is visible; the other three: the inguinal ligament, Gimbernat's ligament and the femoral vein are covered by one or more of the femoral fascial layers. The opening is a gap or hiatus which the hernia makes as it breaks through the weak place where the stronger layers of the partition between the inguinal ligament and the pectineal fascia meet the weaker layers of the medial wall of the femoral sheath. The opening lies about 3 cm. lateral to the pubic spine and usually measures about 1 cm. in diameter. An opening of this size admits the glass catgut tube in common use and with this in place the edges which would otherwise fall together are kept apart for inspection. The opening is usually too small to admit the little finger for easy exploration. The four boundaries of the femoral hernial orifice are as follows: In front, the opening does not lie in contact with the inguinal ligament, being separated from it by the three femoral fascial layers, the middle one here being Gimbernat's ligament. This ligament which forms the inner boundary of the opening is also an anterior relation, for having already begun to arise from the inguinal ligament further laterally it is about a quarter of an inch in depth as it lies in front of the orifice. On the outer side, the orifice is separated from the femoral vein by the layers of the femoral sheath. Behind, the orifice abuts against the pectineal fascia. On the inner side of the opening lies the curved edge of Gimbernat's ligament. If the surgeon now explores the opening with an artery forceps or probe, or if large enough, with his little finger, he will find that the inner edge lies, not at the iliopectineal line, but usually a centimetre or more below. It is not possible to establish by inspection from below that the inner boundary of this opening is in fact Gimbernat's ligament, for this ligament is covered and concealed by the fascia of Scarpa. The surgeon can, however, satisfy himself that the femoral hernial orifice, which is now under observation, lies at the neck of the hernial sac when he withdraws the sac for ligature, and also that the orifice lies at the constriction marks on the bowel when he operates for strangulated hernia. He also realises that the opening is well below the iliopectineal line when he attempts, as a method of repair, to stitch the inguinal ligament to the pectineal (Cooper's) ligament, a task which is difficult or impossible when the orifice is of the usual small size. Gimbernat's ligament Gimbernat's ligament, also named the lacunar ligament and the pectineal part of the inguinal ligament, is a well-hidden structure, for it cannot be seen from below, being covered by the fascia of Scarpa. The ligament also fuses with the pectineal fascia, and this union hides its deep attachments. It is often stated that the ligament can be seen from within the 249 W. J. LYTLE abdomen but this is not so, for it is concealed by the posterior wall of the inguinal canal. Part of the ligament is in view when the inguinal canal is opened. This is the inner or superficial part with a straight outer edge lying some distance from the femoral vein. This is only part of Gimbernat's ligament although it is often referred to as the complete ligament. The deep outer part of the ligament is hidden beneath the inguinal canal. When operating on direct hernia where the posterior wall of the inguinal canal is defective, there is a good opportunity to study both parts of the ligament. The inner or superficial part, which presents in the inguinal canal, has thick tendinous fibres which are nearly parallel; while in the outer or deep part the fibres are thin and radiating (Fig. 4). The ligament in nearly its whole extent is attached to the iliopectineal line, but the outstanding feature, which can now be confirmed, is that the curved outer margin is fixed to the pectineal fascia 1 to 2 cm. below the iliopectineal line. The curved edge of Gimbernat's ligament is apparently placed below the iliopectineal line, because this point of attachment lies nearer the inguinal ligament and the curve on its outer margin can thus be narrowed to fit snugly around and give support to the femoral canal and femoral vein.

- -FEMORAL VEIN ILIOPECTINEAL LINE PECTINEAL PART OF INGUINAL LIGAMENT EXTERNA~L l l|_ (GIMBERNAT'Sl l l LIGAMENT) OBLIQUE M. l | _, DEEP PART SUPERFICIAL PART

FASCIA LATA (SCARPA'S FASCUBA REMOVED) INE

Fig. 4. Gimbernat's ligament. The posterior wall of the inguinal canal has been removed. The deep part of Gimbernat's ligament, although depending for its strength on radiating fibres from the inguinal ligament, is really part of the fascia lata and derived from it in a striking way. As the inguinal ligament passes medially over the femoral vein, it twists through 90 degs. on its way to its insertion into the pubic tubercle and iliopectineal line. The 250 FEMORAL HERNIA lower margin of the outer three-quarters of the inguinal ligament, which faces distally, now becomes the straight margin of the superficial or tendinous part of Gimbernat's ligament which faces backwards and outwards. The fascia lata, arising from the lower edge of the middle part of the inguinal ligament, passes down in the anterior wall of the femoral sheath. The fascia lata, attached to the edge of the superficial

/ILIOPECTINEAL LINE

/.|i ,FEMORAL CANAL

._HENLE'S LIGAMENT _ _ rS PECTINEAL PART OF INGUINAL LIGAMENT EXTERNAL.l _ '(GIMBERNAT'S LIGAMENT) OBLIQUE M.\ .,DEEP PART Nd ...__ _z,SUPERFICIAL PART

__ _ X~~~~~~~~~~~NSERTIONOF POSTERIOR WAkL TRANSVERSUS OF INGUINAL CANAL - * (CNJON TENDON)

FASCIA LATA _ (SCARPA'S FASCIA REMOVED)

Fig. 5. Gimbernat's ligament, the femoral ring and canal. The transversely cut posterior inguinal wall has been detached from the superficial part of Gimbernat's ligament and retracted upwards and backwards. or tendinous part of Gimbernat's ligament which has twisted to face backwards-and outwards, turns with the ligament and secures an attachment to the iliopectineal line and pectineal fascia. In this way a fascial extension outwards from the thick tendinous part of Gimbernat's ligament is provided, which brings the ligament close to the femoral vein. When the femoral canal is short, as in Figures 4 and 5, the curved edge of Gimbernat's ligament lies against the transversalis fascia covering the femoral vein. When the canal is longer its lower end separates the ligament from the vein. The curved edge of Gimbernat's ligament is normally not a free edge, for it joins at an angle the thinner fascia lata or middle layer of the inner surface of the femoral sheath (Fig. 4). This junction is torn through when the femoral sac pushes its way into the groin to form a femoral hernia. The curved edge of Gimbernat's ligament then becomes a free edge lying on the inner side of the neck of the sac. Gimbernat's ligament measures about 3 cm. in length from the pubic spine to the curved outer edge. The deep part of the ligament, as will be mentioned later, can be exposed by a special dissection which allows the surgeon to get beneath 251 W. J. LYTLE the inguinal canal. This exposure also enables him to confirm that the curved edge of Gimbernat's ligament lies at the neck of the sac and well below the iliopectineal line (Fig. 9). The crural or femoral ring At the upper end of the femoral canal, at the level of the iliopectineal line, lies the crural or femoral ring which is normally present and stands wide open. The peritoneum is free to bulge into this opening and to recede from it with changing conditions in the abdomen and variations in the position of the lower limb. Hamilton Russell (1906) found many pre- formed congenital sacs in childhood and appears to have based his " Saccular Theory of Hernia" on the view that bulging of the peritoneum through the femoral ring constitutes a hernia. The boundaries of this opening are the iliopectineal line, the external iliac vein, the trans-

ARCUATE LINE TRANSVERSUS M.

THOMPSON'S _ -is | ffi LlIGAM ENT * ---(THICKENED :: TRANSVERSALUS FASCIA)

- FEMORAL CANAL

, %. PECTINEAL LIGAMENT (COOPER'S LIGAMENT)

IL 'HENLE'S LIGAMENT '.ADMIMNCULUM LlINEAE ALBAE

Fig. 6. The femoral canal viewed from within the abdominal cavity. versalis of the posterior wall of the inguinal canal, where there may be a thickening known as Thompson's ligament, and the curved edge of Henle's ligament (Fig. 6). Henle's ligament, a thickened part of the transversalis fascia and triangular in shape, is attached medially to the outer margin of the lower end of the rectus muscle and below to the iliopectineal line. It has a projecting outer curved edge which forms the inner boundary of the femoral ring. The ligament of Henle is only seen from within the 252 FEMORAL HERNIA abdomen and much confusion has arisen because its outer curved edge is generally mistaken for the similarly shaped edge of Gimbernat's ligament. Antonia de Gimbernat's original account of the ligament may have given rise to this confusion, for according to Cloquet, as quoted by Astley Cooper (1844), his ligament is described as a composite structure which included both Henle's and Gimbernat's ligaments as we know them to-day. The common attachment of the two ligaments to the iliopectineal line was the probable reason why Gimbernat described them as one ligament, although they lie in quite different planes. The bulge of the peritoneum through the femoral ring and down the canal is not a hernia and does not become one until it has burst through the lower end of the femoral canal. This view is opposed to the orthodox teaching, for Leigh Watson (1948), in his book on hernia, gives the generally accepted definition-"A femoral hernia is a protrusion of abdominal or pelvic viscera through the femoral ring into the femoral canal or beyond it." The curved edge of Henle's ligament lies 1 to 2 cm. above and about 1 cm. medial to the curved edge of Gimbernat's ligament (Fig. 5). Henle's ligament sends from its edge a thinner layer of transversalis fascia downwards and inwards to join the fascia on the inner surface of the femoral vein, forming in this way the inner wall of the femoral canal and the upper layer of the femoral partition which lies between the inguinal ligament and the pectineal fascia. The funnel shaped femoral canal, lined by transversalis fascia, has as its upper opening the femoral ring. Below, the canal, which may vary between 1 to 3 cm. in length, ends blindly at or just below the curved edge of Gimbernat's ligament. The inguino-femoral backward turn In the past there has been a tendency to look upon the femoral region as having no depth, for the gap through which a femoral hernia passed was thought to lead directly into the abdominal cavity and to lie at the level of the iliopectineal line, with Gimbernat's ligament as its inner boundary. It has been explained that the femoral sac must pass through two openings before it can claim to be a hernia. These two openings are set widely apart, the upper or femoral ring at the entrance to the femoral canal has Henle's ligament as its inner boundary; while the lower, the femoral hernial orifice of new formation, lies at or near the lower end of the femoral canal and has Gimbernat's ligament on its inner edge. The femoral region therefore has depth and solidity and presents a three dimensional problem not easily understood. The design of this region is set around two main scaffolds: the inguinal ligament and the iliopectineal line. These two supports meet at the pubic spine or tubercle, at two angles in different planes. In relation to the inguinal ligament, the iliopectineal line, on which lies the pectineal (Cooper's) ligament, passes backwards or dorsalwards at an angle of 30 degs. and at the same time about 20 degs. upwards or cephalwards to 253 W. J. LYTLE reach the sacral promontory. The 20 degs. upwards angle is clearly in view from the front when the surgeon opens the inguinal canal, but the backwards angle is difficult to appreciate from this position. From below, the 30 degs. backward angle is obvious in the skeleton with the ligaments in place, but in the living body it is screened from view by the union of Scarpa's fascia and Gimbernat's ligament to the pectineal fascia. It is necessary to keep these two angles in mind when considering the complex anatomy of the femoral region. The anterior abdominal wall, in the form of three fascial or ligamentous -layers, turns back on the inner side of the femoral vein to close the triangular gap caused by the 30 degs. backward deviation of the iliopectineal line from the inguinal ligament. The three layers which take part in the backward turn are the fascia of Scarpa, Gimbernat's ligament which is a continuation backwards of the external oblique aponeurosis, and the transversalis fascia (Fig. 7). These layers form what might be named the

*MEMBRANOUS LAYER OF SUPERFICIAL FASCrA (SCARPAS FASCIA) / :INNOMINATE FASCIA , AEXTERNAL OBLIQUE M. INTERNAL OBLIQUE M.

)'POUPART'S LIGAMENT) PECTINEAL PART OF I1NGUINAL LIGAMENT IMBERNAT'S LIGAMENT) FEMORAL HERNIAL SAC

TRANSVERSUS ME TRANSVERSALIS FASCI PERITONEUM 2- *~~~~~~~~~~-FASCIA PECTINEUS*M.

U PECTINEAL LIGAMENT; SPPO RAFvIUSAU OF PUBIS (COOPER S LIGAMENT)

Fig. 7. Sagittal section of the inguino-femoral region on the medial side of the femoral vein. femoral partition which lies as a barrier between the abdominal cavity and the thigh. Not only do the layers turn back, but they do so at different levels and thus give depth to the femoral region. Indeed, each layer separately finds different levels of attachment to the iliopectineal line, and to the platform of pectineal fascia made wide by the 20 degs. upward deviation of the iliopectineal line in relation to the inguinal ligament. - 254 FEMORAL HERNIA The superficial leaf of the partition is the fascia of Scarpa. The fascia in its outer half turns abruptly over the inguinal ligament and is attached directly behind to the pectineal fascia well below the iliopectineal line. Here it covers Gimbernat's ligament and surrounds the femoral hernial orifice. The inner half of the fascia of Scarpa in this region runs downwards and inwards concealing the inguinal ligament, the pubic spine and the spermatic cord, and fuses with the pectineal fascia and further on with the fascia over the adductor muscles.

POSTERIOR WALL OF INGUINAL CANAL DEEP FEMORAL ARCH -ATTACHMENT OF CREMASTER M. BACKWARD TURN OF TRANEVERSALUS FASCIA TRANSVER5US M.

TRANSVERSALIl (FEMORAL SHEATH) CUT EDGE OF MEMBRANDUS _ LAYEROf SUPERFICiALFA_ClM (SCARPA'S FASCIA)E AND FASCIA LATA

CTINEAL PART OF INGUINAL LIGAMENT FALCIFOR MAR LIGAMENT) OF SAPHENOUS O *GIMBERNAT'S PECTINEAL FASCIA LONG SAPHENOUSW

Fig. 8. The inguino-femoral region. The inguinal ligament has been divided 3cm. from the pubic spine and the cut edges pulled apart. The middle and strong layer of the backward turn is Gimbernat's ligament. The inner or tendinous part is attached high up to the iliopectineal line and lies in the inguinal canal. The outer or fascial part has a double anchorage, for after turning back from the inguinal ligament, it has a first attachment to the pectineal fascia before it proceeds to its terminus at the iliopectineal line. The outer extremity of the ligament has, however, its sole attachment to the pectineal fascia (Figs. 4 and 7), and here its curved edge provides the anterior and inner boundaries of the femoral hernial orifice. The upper or transversalis fascia layer is the most complex of the three strata. The inner or ligamentous part is the ligament of Henle which lies in the posterior inguinal wall behind and also to the lateral side of the insertion of the transversus aponeurosis (conjoint tendon). The ligament is attached high up to the iliopectineal line (Figs. 5 and 6) and has an 255 21 W. J. LYTLE outer curved edge at this level which forms the inner boundary of the crural or femoral ring. The outer or fascial part of this layer turns back at a much lower level. The backward turn of this section of the transversalis fascia is little known, for it is hidden beneath the inguinal canal and seems to have escaped the notice of both surgeons and anatomists. The curve back of the transversalis fascia on the inner side of the femoral vein can, however, be seen in section (Fig. 7), or in a special dissection where the inguinal ligament is cut across on the inner side of the femoral vein and both edges pulled apart to show the anatomy behind the inguinal ligament (Fig. 8). The artist can also show it when, as in Figure 5, he draws the posterior inguinal wall giving a view of both its front and back aspects. The transversalis fascia which extends down from the posterior inguinal wall which lies in front of the femoral vessels passes straight on over them as the deep layer of the femoral sheath. It is on the inner side of the femoral vein where the turn back occurs. This section of the posterior inguinal wall is fixed to the posterior margin of the superficial or tendinous part of Gimbernat's ligament, and beyond this the transversalis fascia curves back on the upper surface of the deep or outer part of Gimbernat's ligament. The transversalis fascia finally reaches the pectineal fascia, and the iliopectineal line which is receding backwards from the inguinal ligament at an angle of 30 degs. and also upwards at an angle of 20 degs. (Fig. 8). The transversalis fascia, where it bends back, forms the medial wall of the femoral canal; and together with the deep outer part of Gimbernat's ligament and the fascia of Scarpa makes up the partition which separates the abdominal cavity from the thigh. At the outer edge of this partition, where it joins the inner wall of the femoral sheath, lies the orifice of a femoral hernia. A view of the femoral canal, the deep part of Gimbernat's ligament and the hernial orifice can be obtained by a special dissection when operating for femoral hernia (Fig. 9). The approach is as follows: After the sac is isolated by the low exposure, the external or superficial inguinal ring is cut outwards for two inches to open the inguinal canal. Instead of cutting through the cremaster muscle as in inguinal hernia operations or in Lotheissen's repair for femoral hernia, the surgeon dissects downwards between the cremaster layer and the external oblique aponeurosis. After separating the posterior wall of the inguinal canal from the back of the superficial part of Gimbernat's ligament, he finds a plane of cleavage between the deep part of Gimbernat's below and the transversalis fascia above. In this exposure the backward turn of the transversalis fascia which forms the outer wall of the femoral canal is seen above, while the deep outer part of Gimbernat's ligament lies below. The neck of the femoral sac lies at the outer curved edge of Gimbernat's ligament where it pene- trates the transversalis fascia at the lower end of the femoral canal. When the sac has been removed it can be verified that the curved edge of Gimbernat's ligament lies well below the level of the iliopectineal line. I 256 FEMORAL HERNIA have used this approach, which I have named the " inter-partition operation," to repair femoral herniae, but I find it is too cramped and difficult to be satisfactory. The backward curve of the inguino-femoral region has a bearing on the operative treatment of both inguinal and femoral herniae. Two operations are commonly used, one for inguinal and the other for femoral hernia, in which the posterior wall of the inguinal canal is divided above the inguinal ligament and the upper cut edge stitched directly to the pectineal (Cooper's) ligament on the iliopectineal line. The former is often referred to as Cooper's ligament operation, while the latter is named the Lotheissen operation. On the inner side of the femoral vein the posterior wall of the inguinal canal, as we have seen, passes downwards to the inguinal ligament, and from there its extension backwards reaches the iliopectineal line.

INTERNAL OBLIQUE MW"

TRANSVERSALIS FASCIA ,.,TURNING BACK CREMASTER M. iI_)"

NECK OF SAC v\\SUPERFICIAL AND 'DEEP PARTS OF PECTINEAL PART OF INGUINAL LIGAMENT FEMORAL SAC' (GIMBERNAT'S LIGAMENT)

Fig. 9. " The inter-partition operation." The posterior inguinal wall is separated from the back of the superficial part of Gimbernat's ligament to expose the neck of the sac lying between the transversalis fascia above and the deep part of Gimbernat's ligament below. Direct suture to the pectineal (Cooper's) ligament drags back the posterior inguinal wall out of its normal plane and the new barrier stands out by itself, under tension and without support from in front. Variation in the position and size of the hernial orifice In the common type offemoral hernia the opening lies obliquely between the inner wall of the femoral sheath and the curved edge of Gimbernat's 257 22 W. J. LYTLE ligament, and faces downwards and inwards. The orifice may be placed further out in the anterior wall of the femoral sheath, a variety known as prevascular hernia. The hernia may also present more medially where it passes through the outer part of Gimbernat's ligament. Other and still rarer varieties have been described. The hernial orifice usually measures about 1 cm. in diameter but in long standing cases the opening may enlarge to admit one or more fingers. As the opening increases in size the inguinal ligament and the femoral vein are encroached upon. The outer curved edge of Gimbernat's ligament, which is slung to the pectineal fascia below the iliopectineal line, is pushed upwards, and the neck of the sac abuts against the fibres of the ligament which a little further medially are attached to the iliopectineal line. As the femoral orifice enlarges, its inner edge is pushed upwards and comes to lie with Henle's ligament at the iliopectineal line, and the femoral canal has then ceased to exist. The outer edge in a large opening is pushed downwards to lie more distally on the inner surface of the femoral sheath. The femoral canal may also be absent in those rare cases where Gimbernat's ligament fails to gain an attachment to the pectineal fascia and passes directly to the iliopectineal line, leaving a crevice or interspace which extends up to this line between the pectineal fascia and Gimbernat's ligament. Here the outer edge of Gimbernat's ligament and the femoral hernial orifice lie at or near the femoral ring. Aetiology of femoral hernia The commonly accepted theory is that the hernia is acquired and is due to intra-abdominal pressure forcing the abdominal contents, covered by the hernial sac, through the femoral ring. The other, the congenital or saccular theory of Hamilton Russell (1906), claims that where a femoral hernia exists there was always present at birth a peritoneal diverticulum or sac in the femoral canal. Finally there is Buckley's theory which relates femoral hernia and fatty hernia of the linea alba (epigastric hernia) to the same cause. Buckley states his views as follows (1924): " Man has an acknowledged weakness in the abdominal parietes at the crural ring. I have formed the opinion that under the influence of intra-abdominal pressure the properitoneal fat is herniated under Poupart's ligament between the femoral vein and Gimbernat's ligament into the thigh, carrying with it a small peritoneal diverticulum." In all these theories the femoral or crural ring is accepted as the site of the defect in femoral hernia. I favour Buckley's theory but suggest that the weakness lies in the femoral partition at the lower end of the femoral canal. The cause of such weakness may be some defect in the sealing off by the transversalis fascia on the front and inner side of the femoral vein, or by poor develop- 258 FEMORAL HERNIA ment of Gimbernat's ligament, or by a femoral canal which leaves a large space between Gimbernat's ligament and the femoral vein, or by perforation of the femoral partition by lymphatics passing from the thigh into the abdomen. In this theory the properitoneal fat is held to be the vanguard of the hernial sac as in fatty hernia of the linea alba. In support of Buckley's opinion is the finding of protrusions of extra-peritoneal fat through the femoral partition, without hernial sacs or with small sacs. One difficulty however is that his theory does not explain the development of a hernia free from extra-peritoneal fat. OPERATIONS Operations for the cure of femoral hernia after the sac has been removed can be divided into two main groups: the high operations which aim to close or erect a barrier at the upper end of the femoral canal at the femoral ring, and the low operations where the repair takes place at the femoral hernial orifice at the lower end of the canal. High operations The femoral ring can be approached by an extra-peritoneal exposure in which the recti muscles are separated in the middle line. Cheatle (1921) and Henry (1936) used this approach. Various methods have been used to close the femoral ring. The anterior and posterior boundaries can be approximated by sutures, or a flap of pectineal fascia, or periosteum raised to form a barrier at the ring. It should be remembered that it is not the inguinal ligament which forms the anterior boundary of the femoral ring, but the posterior wall of the inguinal canal which lies behind the ligament. McEvedy (1950) used an approach through the lower and outer part of the rectus sheath and stitched the posterior wall of the inguinal canal (conjoint tendon) to Cooper's ligament. The operation in common use to-day is Lotheissen's where the approach is through the inguinal canal. The posterior wall is cut transversely and the upper cut edge is sutured directly to the pectineal (Cooper's) ligament on the iliopectineal line. The iliopectineal line is the normal attachment of the posterior inguinal wall on the inner side of the femoral vein, but this wall having reached the inguinal ligament, its further extension makes a detour backwards on the upper surface of the deep part of Gimbernat's ligament before it reaches its insertion into the iliopectineal line. In this operation the divided posterior wall is pulled backwards out of its normal plane and lies taut and deprived of the support of the inguinal and Gimbernat's ligaments. It is reasonable to do a repair at the upper end of the femoral canal but it should be realised that this is well above the point where the hernia has broken through the defences of the femoral region. While flap or darn operations of the femoral ring may be successful, it is more uncertain that 259 22-2 W. J. LYTLE approximation of the anterior and posterior boundaries of the ring, which normally lie far apart, will give a firm and permanent closure. Even if the repair tears away in these operations, it can be said in their favour that they give the orifice of the femoral hernia, whose edges fall together naturally, time to heal without disturbance. A point of equal or greater importance is whether the avenue of approach in the repair of a femoral hernia by the high operations can give rise to weakness of the abdominal wall. When the recti muscles are separated in Cheatle's or Henry's operation little damage is done to the abdominal musculature. In McEvedy's operation the transversalis fascia of the anterior abdominal wall, here represented by Henle's ligament, is detached from the outer border of the lower end of the rectus abdominis muscle. An area of weakness may thus be left in the posterior wall of the inguinal canal at the outer border of the rectus muscle, which might lead to a direct inguinal hernia. In Lotheissen's operation the posterior wall of the inguinal canal is deliberately cut across and the upper cut edge is turned backwards out of its normal plane and sutured to Cooper's ligament on the iliopectineal line. If this repair which lies unsupported and under tension tears away, a direct inguinal hernia is likely to result. Wakeley (1940), who followed up a large personal series of operations, 610 in all, for femoral hernia by the inguinal or Lotheissen's method and by the low or femoral route, states: " I am sure that in my figures the high or inguinal route for femoral hernia was responsible for most of the recurrences and not only so, but in a large percentage of cases a direct inguinal hernia followed the high operation." Low operations The sac is exposed in the thigh preferably by an oblique incision parallel to and above the groin crease (Holden's line) and after ligature of the neck the stump is replaced within the abdomen. The femoral hernial orifice which lies at the neck of the sac is now closed. This circular opening is the hole in the three layered femoral partition at the lower end of the femoral canal which has been breached by the hernia. The opening has strong and unyielding walls as is realised in cases of strangulated hernia, the front and inner margins being reinforced by Gimbernat's ligament. Marcy (1892), a pioneer in hernia repair, used a purse-string suture to close the orifice, and the method recommended is based on his work. The edges of the hernial orifice tend to fall together after the sac has been removed, and to keep them apart and ready for suture the insertion of a glass catgut tube is useful. For the usual opening, measuring 1 cm. in diameter, a four point suture is used which picks up Gimbernat's ligament above and on the inner side, the pectineal fascia behind and the femoral sheath laterally. For large openings five or six insertions of the needle are necessary. In this type of suture Gimbernat's ligament is fixed to its normal attachment to the inner wall of the femoral sheath, and the edges 260 FEMORAL HERNIA of the circular opening are brought together with minimum tension and distortion. An unabsorbable suture is preferred to catgut (Fig. 10). The common repair by the femoral route is suture of the inguinal ligament to the pectineal fascia. This operation is not favoured for it displaces the inguinal ligament backwards and neglects the direct repair of Gimbernat's ligament. It is sometimes advised that the hernial orifice be enlarged sufficiently to allow suture of the inguinal ligament to Cooper's ligament. This operation not only damages the femoral partition but also causes marked displacement of the inguinal ligament and attempts from below to close the femoral ring which normally lies open.

Fig. 10. Purse-string suture of the femoral hernial orifice. To avoid any displacement of tissues a barrier can be raised against the hernial orifice, either by a flap of pectineal fascia turned up, or by one turned down from the external oblique aponeurosis. This method does not appear to provide as strong a repair as the purse-string suture. In strangulated hernia the low operation appears to be the one ofchoice, for the femoral hernial orifice which lies at the point of constriction is directly before the surgeon and division of its inner edge, where Gimbernat's ligament lies, is easily carried out. There should be no fear of injuring an abnormal obturator artery which if present lies higher up 261 W. J. LYTLE at the femoral ring. The low operation may give insufficient room when resection of gut is necessary and it is inadvisable for this purpose to enlarge the hernial orifice. It seems preferable to resect the bowel after delivering the damaged gut into the abdomen through a mid-line supra- pubic incision, rather than risk weakness in the inguinal canal which might result when the inguinal approach of Lotheissen is used. Butters (1948), in a careful review of 120 cases treated by the low operation and personally examined by him, found the recurrence rate to be 3.3 per cent. These figures included cases of strangulation and the period of follow up after operation varied from two to six years. CONCLUSIONS The femoral or crural ring and the femoral hernial orifice are openings which lie half an inch or more apart, the former at the upper end of the femoral canal at the level of the iliopectineal line has Henle's ligament as its inner boundary, while the latter at the lower end of the canal is related to Gimbernat's ligament. The high operations, which are usually difficult, seek to close the femoral ring which normally lies open and leave untouched the essential defect lower down. The low operation by a purse-string suture gives a strong repair ofthe femoral hernial orifice which is the gap in the femoral defences breached by the hernia. REFERENCES BUCKLEY, J. P. (1924) Brit. J. Surg. 12, 60. BUTTERS, A. G. (1948) Brit. med. J. 2, 743. CHEATLE, L. (1921) Brit. med. J. 2, 1025. COOPER, Sir A. (1844) The anatomy and surgical treatment of abdominal hernia. Philadelphia. Lea and Blanchard. GALLAUDET, B. B. (1931) A Description of the Planes of Fascia of the Human Body. New York. Columbia University Press. HENRY, A. K. (1936) Lancet 1, 531. MCEVEDY, P. G. (1950) Ann. Roy. Coll. Surg. Engl. 7, 484. MARCY, H. 0. (1892) The Anatomy and Surgical Treatment of Hernia. New York. Appleton. RUSSELL, R. H. (1906) Lancet 2, 1197. WAKELEY, C. P. G. (1940) Lancet 1, 822. WATSON, L. F. (1948) Hernia, 3rd ed. London; Henry Kimpton.

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