Individual features of hernias

Inguinal hernia

Surgical anatomy

The superficial inguinal ring is a triangular aperture in the aponeurosis of the external oblique and lies 1.25 cm above the pubic tubercle. The ring is bounded by a superomedial and an inferolateral crus joined by the criss-cross intercrural fibres. Normally, the ring will not admit the tip of the little finger.

The deep inguinal ring is a U-shaped condensation of the transversalis fascia and it lies 1.25 cm above the inguinal (Poupart’s) ligament, midway between the symphysis pubis and the anterior superior iliac spine. The transversalis fascia is the fascial envelope of the abdomen and the competency of the deep inguinal ring depends on the integrity of this fascia.

The inguinal canal. In infants the superficial and deep inguinal rings are almost superimposed and the obliquity of the canal is slight. In adults the inguinal canal, which is 3.75 cm long, is directed downwards and medially from the deep to the superficial inguinal ring. In the male the inguinal canal transmits the spermatic cord, the ilio-inguinal nerve and the genital branch of the genitofemoral nerve. In the female the round ligament replaces the spermatic cord.

Boundaries of the canal. Figure 62.4 illustrates the canal, viewing the structures from superficial to deep as is seen at operation. The anterior boundary comprises mainly the external oblique aponeurosis with the conjoined muscle laterally. The posterior boundary is formed by the fascia transversalis and the conjoined tendon (internal oblique and transversus abdominus medially). The inferior epigastric vessels lie posteriorly and medially to the deep inguinal ring. 

The superior boundary is formed by the conjoined muscles (internal oblique and transversus) and the inferior boundary is the inguinal ligament.

An indirect hernia travels down the canal on the outer (lateral and anterior) side of the spermatic cord. A direct hernia comes out directly forwards through the posterior wall of the inguinal canal. While the neck of the indirect hernia is lateral to the inferior epigastric vessels, the direct hernia usu­ally emerges medial to this except in the saddle-bag or pantaloon type, which has both a lateral and a medial component. An inguinal hernia can be differentiated from a femoral hernia by ascertaining the relation of the neck of the sac to the medial end of the inguinal ligament and the pubic tubercle, i.e.in the case of an inguinal hernia the neck is above and medial, while that of a femoral hernia is below and lateral (Fig. 62.4). Digital control of the internal ring may help in distinguishing between an indirect and a direct inguinal hernia, although some reports have found the preoperative diagnosis to be incorrect as often as correct.

Indirect (syn. oblique) inguinal hernia

This is the most common of all forms of hernia (see ‘Aetiology’). It is most common in the young, whereas a direct hernia is most common in the old. In the first decade of life inguinal hernia is more common on the right side in the male. This is no doubt associated with the later descent of the right testis and a higher incidence of failure of closure of the processus vaginalis. In adult males, 65 per cent of inguinal hernias are indirect and 55 per cent are right-sided. The hernia is bilateral in 12 per cent of cases.Three types of indirect inguinal hernia occur (Fig 62.5)

BubonoceleWhen the hernias limited to the inguinal canal

Funicular the processus vaginalis is closed just above the epididymis the content of the sac can be felt separately from the testis, which lies below the hernia

Complete (syn. scrotal) — a complete inguinal hernia is rarely present at birth but is commonly encountered in infancy. It also occurs in adolescence or adult life. The testis appears to lie within the lower part of the hernia.

Clinical features

Occurring at any age, males are 20 times more commonly affected than females. The patient complains of pain in the groin or pain referred to the testicle when performing heavy work or taking strenuous exercise. When asked to cough a small transient bulging may be seen and felt together with an expansile impulse. When the sac is still limited to the inguinal canal, the bulge may be better seen by observing the inguinal region from the side or even looking down the abdominal wall while standing behind the respective shoulder of the patient.

As an indirect inguinal hernia increases in size it becomes apparent when the patient coughs and persists until reduced (Fig. 62.6). As time goes on the hernia comes down as soon as the patient stands up. In large hernias there is a sensation of weight, and dragging on the mesentery may produce epigastric pain. If the contents of the sac are reducible, the inguinal canal will be found to be commodious.

In infants the swelling appears when the child cries. It can be translucent in infancy and early childhood, but never in an adult. In girls an ovary may prolapse into the sac.

Differential diagnosis in the male.

  A vaginal hydrocele (Fig. 62.7);

  an encysted hydrocele of the cord;

  spermatocele;

  a femoral hernia;

  an incompletely descended testis in the inguinal canal — an inguinal hernia is often associated with this condition;

a lipoma of the cord — this is often a difficult, but unimportant, diagnosis. It is usually not settled until the parts are displayed by operation.

NB. Examination using finger and thumb across the neck of the scrotum will help to distinguish between a swelling of inguinal origin and one which is entirely intrascrotal.

Differential diagnosis in the female.

      A hydrocele of the canal of Nuck is the commonest differential diagnostic problem;

  a femoral hernia.

Treatment of indirect inguinal hernia

Operative treatment. Operation is the treatment of choice. It must be remembered that patients who have a bad cough from chronic bronchitis should not be denied an operation, for these are the very people who are in danger of getting a strangulated hernia. In adults, local, epidural or spinal, as well as general, anaesthesia can be used.

Inguinal herniotomy. This is the basic operation which entails dissecting out and opening the hernial sac, reducing any contents, and then transfixing the neck of the sac and removing the remainder. It is employed either by itself or as the first step in a repair procedure (herniorrhaphy). By itself it is sufficient for the treatment of hernia in infants, adoles­cents and young adults. Any attempts at repair in such cases may, in fact, do more harm than good.

In infants it is not necessary to open the canal, as the internal and external rings are superimposed. Excellent results are obtained. The operation is usually now performed as a day case unless there are additional medical or social problems.

Herniotomy and repair (herniorrhaphy). This operation consists of: (1) excision of the hernial sac; plus (2) repair of the stretched internal inguinal ring and the transversalis fascia; and (3) further reinforcement of the posterior wall of the inguinal canal. (2) and (3) must be achieved without tension resulting in the wound and various techniques exist to achieve this, e.g. Shouldice operation, fascial flaps or polypropylene mesh implants.

Operative procedures

1.     Excision of the hernial sac (adult herniotomy). An incision is made in the skin and subcutaneous tissue 1.25 cm above and parallel to the medial two-thirds of the inguinal ligament. In large irreducible hernias the incision may be extended laterally or into the upper part of the scrotum. After dividing the superficial fascia and securing haemostasis, the external oblique aponeurosis and the superficial inguinal ring are identified. The external oblique aponeurosis is incised in the line of its fibres and the structures beneath are carefully separated from its deep surface before completing the incision through the superficial inguinal ring. In this way, the ilio-inguinal nerve is safeguarded. With the inguinal canal thus opened, the upper leaf of the external oblique is separated from the internal oblique by blunt dissection. In the same way, the lower leaf is separated from the contents of the inguinal canal until the inner aspect of the inguinal ligament is seen. The cremasteric muscle fibres may he divided longitudinally to display the spermatic cord, but this is by no means essential.

Excision of the sac. The indirect sac may be distinguished as a pearly white structure lying on the outer side of the cord and, when the internal spermatic fascia has been incised longitudinally, it can usually be dissected out and then opened between haemostats.

Variations in dissection. If the sac is small, it can be freed in tutu. If it is of the lung funicular or scrotal type, or is extremely thickened and adherent, the fundus must not be sought, for in so doing the blood supply to the testis may be compromised. The sac is freed within the inguinal canal and divided circumferentially such that the fundus remains in the scrotum. Care must be taken to avoid damage to the vas and spermatic artery when freeing the sac posteriorly.

An adherent sac can be separated from the cord by first injecting saline under the posterior wall from within (hydrodissection). A similar tactic is employed when dissecting the gossamer sac of infants and children.

Reduction of contents. Intestine or omentum is returned to the peritoneal cavity. Omentum is often adherent to the neck or fundus of the sac: if to the neck, it is freed, and if to the fundus of a large sac. it may be transfixed, ligated and cut across at a suitable point. The distal part of the omentum, like the distal part of a large scrotal sac, can be left in situ (the fundus should, however, not be ligated).

Isolation and ligation of the neck of the sac. Whatever type of sac is encountered, it is necessary to free its neck by blunt dissection until the parietal peritoneum can be seen on all sides. The dissection is only considered complete when the extraperitoneal fat has been encountered and the inferior epigastric vessels are seen on the medial side. It used to be considered essential to open the sac to ensure that no bowel or omentum was adherent to the neck. If the sac is obviously empty, it is sufficient simply to reduce it, close the internal ring and perform a herniorrhaphy if required. If the sac is opened, all contents should be reduced and the neck transfixed as high as possible before excising the sac.

2.       Repair of the transversalis fascia and the internal ring. When the internal ring is weak and stretched, and the transversalis is bulging, the repair should include a technique of narrowing the deep ring, for example the Lyric method of narrowing the ring with lateral dis­placement of the curd (Fig. 62.8) or the Shouldice method, whereby the ring and fascia are incised and carefully separated from the deep inferior epigastric vessels and extraperitoneal far before an overlapping repair (‘double breasting’) of the lower flap behind the upper flap is performed. In the classic Shouldice operation, a third and fourth layer of tension free suturing, using monofilament materials, polypropylene, polyamide or wire, is placed between the internal oblique aponeurosis arch and the inguinal ligament (Fig. 62.9).

3.       Reinforcement of the posterior inguinal wall. This is achieved by suturing without tension between the tendinous apuneurotic arch of internal oblique to the under surface of the inguinal ligament and to the pubic tubercle (as described above in the Shouldice operation) or by reinforcing the posterior wall of the canal with a prosthetic mesh. Care is taken when suturing not to pick up the same tendinous bundle for each suture. Suturing of muscle bundles is of no value. The suturing method can include a rectus-relaxing incision (Halsred—Tanner). The Lichtenstein tension-free herniaplasty involves placement of an approximately 16 x 8 cm (tailored to the individual patient’s requirements) mesh as an extra lamina, anterior to the posterior wall and overlapping it generously in all directions, including medially over the pubic tubercle. Other historical techniques, which should now be abandoned because of poor results, include overlapping the external oblique behind the cord (making it lie subcutaneously). Special care was needed to avoid excessive narrowing of the new external ring which could jeopardise the vascular supply to and the venous return from the testis.

4.       Completion of operation. If desired, the cremasteric muscle can be reconstituted: the external oblique is directly sutured or overlapped leaving a new external ring which should accommodate the tip of a finger (Fig. 62.10).

A truss. A truss may be used when operation is contraindicated or when operation is refused. Its use should be mainly historical as there are very few contraindications to surgery with today’s variety of anaesthetic techniques. If a truss is to be worn, the hernia must be reducible. A rat tailed spring truss with a perineal band to prevent the truss slipping will, with due care and attention, control a small or moderate size inguinal hernia. A truss must be worn continuously during waking hours, kept clean and in proper repair, and renewed when it shows signs of wear. It must be applied before the patient gets up and while the hernia is reduced. A properly fitting truss must control the hernia when the patient stands, with his legs apart, stoops and coughs violently. If it does not it is a menace, for it increases the risk of strangulation. There is no place for trusses in the management of infant hernias. If an infant hernia becomes suddenly irreducible, urgent operative repair is indicated. Otherwise, the infant hernia can be left alone until the child is over 3 months old when routine day-case repair can be performed.

Direct inguinal hernia

In adult males, 35 per cent of inguinal hernias are direct. At presentation, 12 per cent of patients will have a contralateral hernia in addition and there is a four-fold increased risk of future development of contralateral hernia if one is not present at the original presentation.

A direct inguinal hernia is always acquired. The sac passes through a weakness or defect of the transversalis fascia in the posterior wall of the inguinal canal. In some cases the defect is small and is represented by a discrete defect in the transversalis fascia, while in others there is a generalised bulge. Often the patient has poor lower abdominal musculature, as shown by the presence of elongated bulgings (Malgaigne’s bulges). Women practically never develop a direct inguinal hernia (Brown). Predisposing factors are smoking, and occu­pations that involve straining and heavy lifting. Damage to the ilio-inguinal nerve (previous appendicectomy) is another cause, due to resulting weakness of the conjoined tendon.

Direct hernias do not often attain a large size or descend into the scrotum (Fig. 62.11). In contrast to an indirect inguinal hernia, a direct inguinal hernia lies behind the spermatic cord. The sac is often smaller than the hernial mass would indicate, the protruding mass mainly consisting of extraperitoneal fat. As the neck of the sac is wide, direct inguinal hernias do not often strangulate.

Funicular direct inguinal hernia (syn. prevesical hernia). This is a narrow-necked hernia with prevesical fat and a portion of the bladder that protrudes through a small oval defect in the medial part of the conjoined muscle just above the pubic tubercle. It occurs principally in elderly males and occasionally becomes strangulated. Unless there are definite contraindications, operation should always be advised.

Dual (syn. saddle bag; pantaloon) hernia. This type of hernia consists of two sacs which straddle the inferior epigastric artery, one sac being medial and the other lateral to this vessel. The condition is not rare and is a cause of recurrence, one of the sacs having been overlooked at the time of operation.

Operation for direct hernia. The principles of repair of direct hernias are the same as those of an indirect hernia with the exception that the hernia sac can usually be simply inverted after the sac has been dissected free and the transversalis fascia reconstructed in front of it. This reconstruction of the posterior wall of the inguinal canal should be undertaken by the Shouldice repair or mesh implant using the Lichtenstein technique (Figs 62.9 and 62.10). The darn operation is no longer acceptable because of its high recurrence rate and slow rehabilitation.

Strangulated inguinal hernia

Pathological and clinical features are described earlier in this chapter. Strangulation of an inguinal hernia occurs at any time during life and in both sexes. Indirect inguinal hernias stran­gulate more commonly, the direct variety not so often owing to the wide neck of the sac. Sometimes a hernia strangulates on the first occasion that it descends; more often strangulation occurs in patients who have worn a truss for a long time, and in those with a partially reducible or irreducible hernia.

In order of frequency, the constricting agent is: (a) the neck of the sac; (b) the external inguinal ring in children; and (c), rarely, adhesions within the sac.

Contents

 Usually, the small intestine is involved in the strangulation; the next most frequent is the omentum; sometimes both are involved. It is rare for the large intestine to become strangulated in an inguinal hernia, even when the hernia is of the sliding variety.

Strangulation during infancy

The incidence of strangulation is 4 per cent (Gross) and the ratio of females to males is 5:1. More frequently the hernia is irreducible but not strangulated. In most cases of strangulated inguinal hernia occurring in female infants the content of the sac is an ovary or an ovary plus its fallopian tube.

Treatment of strangulated inguinal hernia

The treatment of strangulated hernia is by emergency operation (‘The danger is in the delay not in the operation’, Sir Astley Paston Cooper). Vigorous resuscitation with intrave­nous fluids, nasogastric aspiration and antibiotics is essential, although operation should not be unduly delayed in moribund patients. It is also advisable to empty the bladder, if necessary by catheterisation.  

Inguinal herniotomy for strangulation. An incision is made over the most prominent part of the swelling. The external oblique aponeurosis is exposed and the sac, with its coverings, is seen issuing from the superficial ring. In all but very large hernias, it is possible to deliver the body and fundus of the sac together with its coverings and (in the male) the testis on to the surface. Each layer covering the anterior surface of the body of the sac near the fundus is incised and, if possible, stripped off the sac. The sac is then incised and any fluid, which may be highly infective, drained effectively. The external oblique aponeurosis and the superficial inguinal ring are divided. A finger is then passed into the opening in the sac and, employing the finger as a guide, the sac is slit along its length. If the constriction lies at the superficial inguinal ring, or within the canal, it is readily divided by this procedure. When the constriction is at the deep ring, by applying haemostats to the cut edge of the neck of the sac and drawing them downwards, and at the same rime retracting the internal oblique upwards, it may be possible to continue slitting the sac over the finger towards the point of constriction. When the constriction is too tight to admit a finger, a grooved dissector is inserted and the neck of the sac is divided with a knife in an upward and inward direction, i.e. parallel to the inferior epigastric vessels, under vision. Once the constriction has been divided, the strangulated contents can be drawn down. Devitalised omentum is excised after being securely ligated. Viable intestine is returned to the peritoneal cavity. Doubtfully viable and gangrenous intestine is excised by localised resection. If the hernial sac is of moderate size and can be separated easily from its coverings, it is excised and closed by a purse-string suture. When the sac is large and adherent, much time is saved by cutting across the sac as described earlier. Having tied or sutured the neck of the sac, a repair can be made if the condition of the patient permits. In those circumstances where the incision has been soiled or gangrenous bowel resected, prosthetic mesh is best avoided, although some authorities have successfully unused polypropylene mesh with antibiotic cover.

Conservative measures. These are only indicated in infants. The child is given analgesias and placed in gallow’s traction (the judgement of Solomon position). In 75 per cent of cases reduction is effected and there

appears to be no danger of gangrenous intestine being reduced (Irvine Smith).

NB. Vigorous manipulation (taxis) has no place in modern surgery and is mentioned only to be condemned. Its dangers include:

contusion or rupture of the intestinal wall;

reduction-en-masse: ‘The sac together with its contents is pushed forcibly back into the abdomen; as the bowel will still be strangulated by the neck of the sac, the symptoms are in no way relieved’ (Treves);

reduction into a loculus of the sac;

the sac may rupture at its neck and the contents are reduced, not into the peritoneal cavity but extraperitoneally.

  Maydl’s hernia (syn. hernia-in-W). Maydl’s hernia is rare. The stran­gulated loop of the W lies within the abdomen, thus local tenderness over the hernia is not marked. At operation two comparatively normal-looking loops of intestine are present in the sac. After the obstruction has been relieved, the strangulated loop will become apparent if traction is exerted on the middle of the loops occupying the sac.

Results of operations for inguinal hernia — recurrence. Reported recurrence rates vary between 0.2 and 15 per cent depending on the technique employed. Only by using a meticulous technique, principally concentrating on reinforcement of the posterior wall of the inguinal canal, with the Shouldice technique or mesh hernioplasty, can a recurrence rate of less than 2 per cent be achieved. Only 50 per cent of recurrences will become apparent within 2 years. In a few cases ‘false’ recurrences occur, i.e. another type of hernia occurs — direct after indirect, femoral after inguinal. To the patient it is a recurrence!

The spermatic cord as a barrier to effective closure of the inguinal canal. Even in the elderly patient, removal of the testis and cord is very rarely required for effective repair even in cases of recurrent inguinal hernia. In operations for multiple recurrences or when previous surgery has been associated with infections or excessive scarring, the operation should be approached through virgin territory, i.e. the preperitoneal route, by an experienced surgeon.

Sliding hernia (syn. hernia-en-glissade) (Fig. 62.12)

As a result of slipping of the posterior parietal peritoneum on the underlying retroperitoneal structures, the posterior wall of the sac is not formed of peritoneum alone, but by the sigmoid colon and its mesentery on the left, the caecum on the right and, sometimes, on either side by a portion of the bladder. It should be clearly understood that the caecum, appendix or a portion of the colon wholly within a hernial sac does not constitute a sliding hernia. A small bowel sliding hernia occurs approximately once in 2000 cases; a sacless hernia once in 8000 cases.

Clinical features

A sliding hernia occurs almost exclusively in males. Five out of six sliding hernias are situated on the left side; bilateral sliding hernias are rare. The patient is nearly always over   40 years of age, the incidence rising with age. There are no clinical findings that are pathognomonic of a sliding hernia, but it should be suspected in a very large globular inguinal hernia descending well into the scrotum. Occasionally large intestine is strangulated in a sliding hernia; more often nonstrangulated large intestine is present behind the sac containing strangulated small intestine.

  Treatment

A sliding hernia is impossible to control with a truss, and as a rule the hernia is a cause of considerable discomfort. Con­sequently, operation is indicated and the results are very good.

Operation. It is unnecessary to remove any of the sliding hernial sac provided that it is freed completely from the cord and the abdominal wall, and that it is replaced deep to the repaired fascia transversalis. In many circumstances it is desirable to perform orchidectomy in order to effect a secure repair. No attempt should be made to dissect the caecum or colon free from the peritoneum under the impression that these are adhesions, in which case peritonitis or a faecal flstula resulting from necrosis of a devascularised portion of the bowel may occur. This is especially liable to occur on the left side, as vessels in the mesocolon may be injured.

Femoral hernia

Femoral hernia is the third most common type of primary hernia. It accounts for about 20 per cent of hernias in women and 5 per cent in men. The overriding importance of femoral hernia lies in the facts that it cannot be controlled by a truss and that of all hernias it is the most liable to become strangulated, mainly because of the narrowness of the neck of the sac and the rigidity of the femoral ring. Strangulation is the initial presentation of 40 per cent of femoral hernias.

Surgical anatomy. The femoral canal occupies the most medial compartment of the femoral sheath and it extends from the femoral ring

above to the saphenous opening below. It is 1.25 cm long and 1.25 cm wide at its base, which is directed upwards. The femoral canal contains fat, lymphatic vessels and the lymph node of Cloquet. It is closed above by the septum crurale, a condensation of extraperitoneal tissue pierced by lymphatic vessels, and below by the cribriform fascia.

The femoral ring is bounded:

anteriorly by the inguinal ligament;

posteriorly by Astley Cooper’s (ileopectineal) ligament, the pubic bone and the fascia over the pectineus muscle;

medially by the concave knife-like edge of Gimbernat’s (lacunar) ligament, which is also prolonged along the iliopectineal line as for Astley Cooper’s ligament;

laterally by a thin septum separating it from the femoral vein.

Sex incidence. The female to male ratio is about 2:1, but it is interesting that whereas the female patients are frequently elderly, the male patients are usually between 30 and 40 years of age. The condition is more prevalent in women who have borne children than in nulliparae.

Pathology. A hernia passing down the femoral canal descends vertically as far as the saphenous opening. While it is confined to the inelastic walls of the femoral canal the hernia is necessarily narrow but, once it escapes through the saphenous opening into the loose areolar tissue of the groin, it expands, sometimes considerably. A fully distended femoral hernia assumes the shape of a retort and its bulbous extremity may be above the inguinal ligament. By the time the contents have pursued so tortuous a path they are usually irreducible and apt to strangulate.

Clinical features. Femoral hernia is rare before puberty. Between 20 and 40 years of age the prevalence rises and continues to old age. The right side (Fig. 62.13) is affected twice as often as the left, and in 20 per cent of cases the condition is bilateral. The symptoms to which a femoral hernia gives rise are less pronounced than those of an inguinal hernia; indeed, a small femoral hernia may be unnoticed by the patient or disregarded for years, perhaps until the day it strangulates. Adherence of the greater omentum sometimes causes a dragging pain. Rarely, a large sac is present.

Differential diagnosis. A femoral hernia has to be distinguished from the following.

An inguinal hernia. The neck of the sac lies above and medial to the medial end of the inguinal ligament at its attachment to the pubic tuber­cle. The neck of the sac of a femoral hernia lies below this (Fig. 62.14). The fundus of an inguinal or a femoral hernia may follow the line of least resistance and occupy a variety of places, for instance, occasionally the fundus of a femoral hernia sac overlies the inguinal ligament.

A saphena varix. A saccular enlargement of the termination of the long saphenous vein, usually accompanied by other signs of varicose veins. The swelling disappears completely when the patient lies flat, while a femoral hernia sac is usually still palpable. In both, there is an impulse on coughing. A saphena varix will, however, impart a fluid thrill to the examining fingers when the patient coughs or when the saphenous vein below the varix is tapped with the fingers of the other hand. Sometimes a venous hum can be heard when a stethoscope is applied over a saphena varix.

An enlarged femoral lymph node. There may be other enlarged lymph nodes to aid the diagnosis. If Cloquet’s lymph node alone is affected, it may be impossible to distinguish from a femoral hernia sac unless there are other clues, such as an infected wound or abrasion on the corresponding limb or on the perineum.

Lipoma.

A femoral aneurysm. See Chapter 15.

A psoas abscess. There is often a fluctuating swelling — an iliac abscess

— which communicates with the swelling in question. If suspected, an examination of the spine and an X-ray will confirm the diagnosis.

A distended psoas bursa. The swelling diminishes when the hip is flexed and osteoarthritis of the hip is present.

Rupture of the adductor longus. Rupture of the adductor longus with haematoma formation — suspected on clinical history.

Hydrocele of a femoral hernial sac. The neck of the sac becomes plugged with omentum or by adhesions, and a hydrocele of the sac results.

Laugier’s femoral hernia. This is a hernia through a gap in the lacunar (Gimbernat’s) ligament. The diagnosis is based on unusual medial position of a small femoral hernia sac. The hernia has nearly always strangulated.

Narath’s femoral hernia. This occurs only in patients with congenital dislocation of the hip and is due to lateral displacement of the psoas muscle. The hernia lies hidden behind the femoral vessels.

Cloquet’s hernia. Cloquet’s hernia is one in which the sac lies under the fascia covering the pectineus muscle. Strangulation is likely. The sac may coexist with the usual type of femoral hernia sac.

Strangulated femoral hernia

A femoral hernia strangulates frequently and gangrene rapidly develops. This is explained by the narrow, unyielding femoral ring. In 40 per cent of cases the obstructing agent is not the lacunar ligament but the neck of the femoral sac itself. A Richter’s hernia is a frequent occurrence (see above).

Treatment of a femoral hernia. The constant risk of stran­gulation is sufficient reason to recommend operation, which should be carried out soon after the diagnosis has been made. A truss is contraindicated because of this risk.

Operative treatment. Several approaches to the femoral hernia have been advocated including the low operation (Lockwood), the high operation (McEvedy) and the inguinal operation (Lotheissen). In all cases the bladder must be emptied by catheterisation immediately before commencing surgery.

(The low operation (Lockwood). The sac is dissected out below the inguinal ligament via a groin-crease incision. It is essential to peel off the anatomical layers which cover the sac. These are often thick and fatty. After dealing with the contents (e.g. freeing adherent omentum) the neck of the sac is pulled down, ligated as high as possible and allowed to retract through the femoral canal. The canal may be closed by suturing the inguinal ligament to the iliopectineal line using three nonabsorbable sutures. An alternative method of closure is to roll a sheet of poly­propylene mesh into a cylinder and anchor the cylinder in the canal with nonabsorbable sutures placed medially, superiorly and inferiorly.

The high (McEvedy) operation. Classically, a vertical incision is made over the femoral canal and continued upwards above the inguinal ligament. An acceptable alternative that heals well and with less pain is to use a ‘unilateral’ Pfannenstiel incision, which can be extended to form a complete Pfannenstiel incision if formal Laparotomy is required. This incision provides good access to the preperitoneal space. Through the lower part of the incision the sac is dissected Out. The upper part of the incision exposes the inguinal ligament and the rectus sheath. The superficial inguinal ring is identified and an incision 2.5 cm above the ring and parallel to the outer border of the rectus muscle is deepened until the extraperitoneal space is identified. By gauze dissection in this space the hernial sac entering the femoral canal can be easily identified. Should the sac be empty and small, it may be drawn upwards; if it is large, the fundus is opened below and its contents, if any, dealt with appropriately before delivering the sac upwards from its canal. The sac is then freed from the extraperitoneal tissue and its neck ligated. An excellent view of the ilio­pectineal ligament is obtained and the conjoined tendon is sutured to it with nonabsorbable sutures. An alternative repair, particularly suitable for recurrent femoral hernias, is to suture a sheet of polypropylene mesh over the femoral canal orifice, anchoring the mesh inferiorly to the ilio­pectineal ligament and medially to the rectus sheath.

An advantage of this approach is that if resection of intestine is required, ample room can be obtained by opening the peritoneum. The disadvantage of this approach is that if infection occurs, an incisional hernia may develop.

Lotheissen’s operation. The inguinal canal is opened as for inguinal herniorrhaphy. The transversalis fascia is incised to the medial side of the epigastric vessels and the opening is enlarged. The peritoneum is now in view; one must be certain that it is the peritoneum and not the bladder or a diverticulum thereof. The peritoneum is picked up with dissecting forceps and incised. It is now possible to ascertain whether any intraperitoneal structure is entering the femoral sac. Should the sac be empty, haemostats are placed upon the edges of the opening into the peritoneum and, by gauze dissection, the sac is withdrawn from the femoral canal. An empty sac can be delivered easily. If strangulation is suspected, as soon as the external oblique has been exposed, the inferior margin of the wound is retracted, thereby displaying the swelling. The coverings of the sac are incised and peeled off, until the sac, dark from contained blood stained fluid, is apparent. The sac is incised and the fluid that escapes is mopped up with care. The retractor is removed and the operation is continued above the inguinal ligament as described above. Once the peritoneum has been opened above the inguinal ligament, one can see exactly what is entering the sac. Should the obstruction lie in a narrow neck of the sac, the neck of the sac may be gently stretched by insertion of a haemostat. (An abnormal obturator artery is present either on the medial or the lateral side of the neck of the sac in 28 per cent of cases.) The contents of the sac are delivered and dealt with appropriately. Sometimes, in order to facilitate reduction of the hernial contents, it becomes necessary to divide or digitally dilate part of the lacunar (Gimbernat’s) ligament.

The Lotheissen repair is effected by suturing the conjoined tendon to the iliopectineal line to form a shutter. While protecting the external iliac/femoral vein with the forefinger, nonabsorbable sutures are passed through the periosteum and Cooper’s ligament overlying the ilio­pectineal line. The retractor is removed and the long ends of the sutures are passed from within, outwards, through the conjoined tendon and tied, thus approximating the conjoined tendon to the iliopectineal line. If there is any tension, a Tanner’s slide will facilitate this step. The incised external oblique is sutured.

An alternative repair is to buttress the femoral canal with a sheet of polypropylene mesh. Once the sac has been dealt with, a sheet of mesh is inserted into the preperitoneal space and anchored inferiorly to the iliopectineal line, inferomedially to Cooper’s ligament and superomedially to the rectus sheath. The transversalis fascia may then be approximated in front of the mesh and the incised external oblique repaired. It should be noted that the peritoneum must be closed before placement of the mesh.

NB. Throughout operations for the repair of a femoral hernia, on the lateral side, the external iliac/femoral vein must be protected, and on the medial side, great care must be taken not to injure the bladder, particularly as a portion of the bladder may form part of the wall of the sac (a sliding femoral hernia).

Umbilical hernia

Exomphalos (syn. omphalocele) occurs once in every 6000 births; it is due to failure of all or part of the midgut to return to the coelom during early foetal life. There is some debate as to whether gastroschisis represents a separate entity or is simply an exomphalos with ruptured membranes, but the debate has little practical importance because the principles of treatment are similar. When the sac remains unruptured, it is semitranslucent (Fig. 62.15) and, although very thin, it consists of two layers — an outer layer of amniotic membrane and an inner layer of peritoneum. Omphaloceles may be divided into those with a fascial defect of less than or greater than 4 cm. The former are termed herniation of the umbilical cord. In smaller defects, a single loop of intestine may not be obvious and ligation of what was thought to be a normal umbilical cord will result in transection of the intestine, leaving the embarrassing problem of an umbilico-enteric fistula.

In large defects the liver, spleen, stomach, pancreas, colon or bladder may be seen through the membrane. The intestine lies freely mobile within the intact sac without evidence of adhesions or inflammation. In contrast, the liver has dense adhesions to the sac, a fact which must be remembered during surgical repair.

Treatment

  Small defects may be closed primarily soon after birth as there is usually no difficulty with disproportion between the size of the abdominal cavity and the volume of the sac contents.

Large defects present a more substantial problem and four techniques have been described: nonoperative therapy, skin flap closure, staged closure, and primary closure

Nonoperative therapy. This is appropriate for premature infants with

a gigantic intact sac or those in whom associated anomalies make survival of a major operation unlikely. The intact sac is painted daily with a desiccating antiseptic solution and, if successful, an eschar forms over  the sac. Eventually granulisation grows in from the periphery and the subsequent ventral hernia can be repaired later.

Skin flap closure. The sac is gently trimmed away enabling inspection of the abdominal contents. The skin is freed from the fascial edges and undermined laterally. The umbilical vessels are ligated or one artery is cannulated for monitoring. The skin flaps are approximated in the midline with simple sutures and the ventral hernia is then closed at a later date (months to years later).

Staged closure. The sac is gently trimmed away from the skin edge and the skin further freed from the fascial attachments. The prosthetic material [polypropylene mesh or expanded polytetrafluoroethylene (PTFE)] is sutured with interrupted nonabsorbable sutures circumferentially to the full thickness of the musculofascial abdominal wall to form a silo. The top of the silo is gathered and tied with umbilical tape. At daily intervals, the silo is opened under strict aseptic conditions and the contents are examined for infection or dehiscence. The viscera are pushed gently back in to the abdominal cavity and the infant is observed for signs of raised intra-abdominal pressure. The silo is then tied at a reduced level and the cycle repeated until the sac is flush with the abdominal wall. At this stage, the fascia may be closed with interrupted sutures and skin closed over the top.

Primary closure. The sac is gently dissected away from the skin edge and the underlying fascia. The intestine is then evacuated completely of meconium and fluid distally and proximally through a nasogastric tube. The abdominal wall is stretched gradually and repeatedly in quadrants, usually achieving a doubling of volume. The viscera are then replaced and the fascial layer is closed primarily, usually under moderate tension. Intragastric pressure monitoring is helpful to prevent undue vena caval compression.

Congenital umbilical hernia. Rarely, a fully developed umbilical herniais present at birth, presumably due to intrauterine epithelialisation of a small exomphalos.

Umbilical hernia of infants and children

This is a hernia through a weak umbilicus which may partial­ly result from failure of the round ligament (obliterated umbilical vein) to cross the umbilical ring and partially from absence of the Richet fascia. Both sexes seem to be equally affected, although there are significant racial differences, with the incidence in black infants reported as up to eight times higher than in white infants. The hernia is often symptomless but increases in size on crying and assumes a classical conical shape (Fig. 62.16). Obstruction or strangulation below the age of 3 years is extremely uncommon.

Treatment. Conservative treatment is indicated under the age of 2 years. When the hernia is symptomless, reassurance of the parents is all that is necessary and 95 per cent of hernias will disappear spontaneously. If the hernia persists at 2 years of age or older, it is unlikely to resolve and herniorrhaphy is indicated. Operation. A small curved incision is made immediately below the umbilicus. The skin cicatrix is dissected upwards and the neck of the sac isolated. After ensuring that the sac is empty of contents, it is either inverted into the abdomen or ligated by transfixion and excised. The defect in the linea alba is closed with interrupted absorbable sutures.

Paraumbilical hernia (syn. supraumbilical or

infraumbilical hernia)

In adults the hernia does not occur through the umbilical scar. It is a protrusion through the linea alba just above or sometimes just below the umbilicus (Fig. 62.17). As it enlarges it becomes rounded or oval in shape, with a tendency to sag downwards. Paraumbilical hernias can become very large. The neck of the sac is often remarkably narrow compared with the size of the sac and the volume of its contents, which usually consist of greater omentum often accompanied by small intestine and, alternatively or in addition, a portion of transverse colon. In long-standing cases the sac sometimes becomes loculated owing to adherence of omentum to its fundus.

Clinical features. Women are affected five times more frequently than men. The patient is usually overweight, and between the ages of 35 and 50 years. Increasing obesity, with flabbiness of the abdominal muscles, and repeated pregnancy are important aetiological factors. These hernias may become irreducible owing to the formation of omental adhesions within the sac. Symptomatically, a large umbilical hernia causes a dragging pain by its weight. Gastrointestinal symptoms are common and are probably due to traction on the stomach or transverse colon. Often there are transient attacks of intestinal colic due to partial intestinal obstruction. In long­standing cases Intertrigo of the adjacent surfaces of skin and trophic ulcers of the fundus are troublesome complications.

Treatment. Untreated, the hernia increases in size and more and more of its contents become irreducible. Eventually, strangulation may occur. Therefore operation should be advised in nearly all cases. If the patient is obese and the hernia is symptomless, operation can be postponed until the patient has lost weight.

Epigastric herniorrhaphy. If the defect is small, a primary herniorrhaphy can be performed. If the defect is large, the repair is best performed with prosthetic buttressing of the abdominal wall. The classic primary repair is that described by Mayo. A transverse elliptical incision is made around the umbilicus and the subcutaneous tissues are dissected off the rectus sheath to expose the neck of the sac. The neck is incised to expose the contents. Intestine is returned to the abdomen and any adherent omentum freed. Excess adherent omentum can be removed with the sac if necessary. The sac is then removed and the peritoneum closed with an absorbable suture. The aponeurosis on both sides of the umbilical ring is mobilised from underlying tissue sufficiently to allow an overlap of 5 or 7.5 cm. Interrupted mattress sutures are then inserted into the aponeurosis, as shown in Fig. 62.18. When this row of mattress sutures has been tied, the overlapping upper margin is stitched to the sheath of the rectus abdominis and the midline aponeurosis. A suction drain should be placed in the wound in fat patients, who ooze blood and liquid fat. The subcutaneous fat and skin are then approximated with deep sutures.

Paraumbilical hernioplasty. In the case of very large primary para­umbilical hernias (fascial defect > 4 cm) or for recurrent paraumbilical hernias, the use of prosthetic material (polypropylene mesh) is recommended.

Additional lipectomy. In patients with a paraumbilical hernia associated with a large, pendulous, fat-laden abdominal wall the operation can, with great advantage, be combined with panniculectomy by fashioning the incisions to embrace a larger area of the fat-laden superficial layers of the abdominal wall.

Strangulation is a frequent complication of a large paraumbilical hernia in adults. Owing to the narrow neck and the fibrous edge of the linea alba, gangrene is liable to supervene unless early operation is carried out. It should also be remembered that in large hernias the presence of loculi may result in a strangulated knuckle of the bowel in one part of an otherwise soft and nontender hernia.

Operation. In early cases, the operation does not differ from that for nonstrangulated cases. Gangrenous contents are dealt with as in other situations. If a portion of the transverse colon is gangrenous, it should be exteriorised by the Paul—Mikulicz method and the gangrenous portion excised. If the ring is large enough to transmit the colon unhampered, it is left alone; otherwise it is enlarged. It is important that the small intestine be thoroughly scrutinised as a small loop may have been trapped and slipped back when the constriction was relieved. If nonviable gut is overlooked, peritonitis quickly supervenes and the symptoms are ascribed to postoperative discomfort. The condition of the patient steadily deteriorates until they succumb after a few days.

Epigastric hernia (syn. fatty hernia of the linea alba)

An epigastric hernia occurs through the linea alba anywhere between the xiphoid process and the umbilicus, usually midway between these structures. Such a hernia commences as a protrusion of extraperitoneal fat through the linea alba, and it was hypothesised that this protrusion occurs at the site where small blood vessels pierced the linea alba. However, only a minority of epigastric hernias is accompanied by blood vessels, and it is more likely that the defect occurs as a result of a weakened linea alba due to abnormal decussation of the fibres of the aponeurosis. More than one hernia may be present and the commonest cause of ‘recurrence’ is failure to identify a second defect at the time of original repair.

A swelling the size of a pea consists of a protrusion of extraperitoneal fat only (fatty hernia of the linea alba). If the protrusion enlarges, it drags a pouch of peritoneum after it and so becomes a true epigastric hernia. The mouth of the hernia is rarely large enough to permit a portion of hollow viscus to enter it; consequently, either the sac is empty or it contains a small portion of greater omentum.

It is probable that an epigastric hernia is the direct result of

a sudden strain tearing the interlacing fibres of the linea alba.

The patients are often manual workers between 30 and 45 years of age.

Clinical features

      Symptomless — a small fatty hernia of the linea alba can be felt better than it can be seen and may be symptomless, being discovered only in the course of routine abdominal palpation.

  Painful — sometimes such a hernia gives rise to attacks of local pain, worse on physical exertion, and tenderness to touch and light clothing. This may be because the fatty contents become nipped sufficiently to produce partial strangulation.

  Referred pain — it is not uncommon to find that the patient, who may not have noticed the hernia, complains of pain suggestive of a peptic ulcer. However, as the majority of these hernias is asymptomatic, symptoms should not be ascribed to the hernia until any gastrointestinal pathology has been excluded.

Treatment

If the hernia is giving rise to symptoms, operation should be undertaken. Operation. An adequate vertical or transverse incision us made over the swelling, exposing the linea alba. The protruding extraperitoneal fat is cleared from the hernial orifice by gauze dissection. If the pedicle passing through the linea alba is slender, it is separated on all sides of the opening by blunt dissection. After ligating the pedicle, the small opening in the linea alba is closed by nonabsorbable sutures in adults and with absorbable sutures in children. When a hernial sac is present, it is opened and any contents are reduced, after which the sac neck is transfixed and the sac excised before repairing the linea alba. If smaller protrusions of fat are found above or below the hernia, these should also be dealt with. If the hernia is large (defect greater than 4 cm in diameter), the repair should be reinforced with polypropylene mesh positioned in the retromuscular plane.

Rare external hernias

Interparietal hernia (syn. interstitial hernia). An interparietal hernia has a hernial sac which passes between the layers of the anterior abdominal wall. The sac may be associated with, or communicate with, the sac of a concomitant inguinal or femoral hernia. Lack of knowledge of this condition is the cause of misdiagnosis and mismanagement.

Other varieties.

 Preperitoneal (20 per cent) — usually the sac takes the form of a diverticulum from a femoral or inguinal hernia.

 Intermuscular (60 per cent) — the sac passes between the muscular layers of the anterior abdominal wall, usually between the external oblique and internal oblique muscles. The sac is nearly always bilocular and is associated with an inguinal hernia.

 Inguinosuperficial (20 per cent) — the sac expands beneath the superficial fascia of the abdominal wall or the thigh. This type is commonly associated with an incompletely descended testis.

Clinical features. The patients (mostly male) present with intestinal obstruction, due to obstruction or strangulation of the hernia. In the preperitoneal variety, as no swelling is likely to be apparent, delays in diagnosis occur and consequently the mortality in this variety is high.

Treatment. Operation is imperative because of intestinal obstruction.

Spigelian hernia. This is a variety of interparietal hernia occurring at the level of the arcuate line. It is very rare with only 1000 cases reported in the literature. The fundus of the sac, clothed by extraperitoneal fat, may lie beneath the internal oblique muscle where it is virtually impalpable. More often it advances through that muscle and spreads out like a mushroom between the internal and external oblique muscles, and gives rise to a more evident swelling. The patient is often corpulent and usually over 50 years of age, men and women being equally affected. Typically, a soft, reducible mass will be encountered lateral to the rectus muscle and below the umbilicus. Diagnosis is confirmed by computerised tomography (CT) or ultrasound scanning, the latter having the advantage of being able to stand the patient upright if no defect is visible in the reclining position. Owing to the rigid fascia surrounding the neck, strangulation may occur.

Treatment. Operation. If a defect is palpable, a muscle-splitting approach is used. After isolating the sac, dealing with any contents, and ligating and excising it, the transversus, internal oblique and external oblique muscles are repaired by direct apposition. If no sac is palpable, a paramedian approach is used and the sac sought in the extraperitoneal space. The repair then proceeds as described above.

Lumbar hernia. Most primary lumbar hernias occur through the inferior lumbar triangle of Petit (Fig. 62.19), bounded below by the crest of the ilium, laterally by the external oblique and medially by the latissimus dorsi. Less commonly, the sac comes through the superior lumbar triangle which is bounded by the twelfth rib above, medially by the sacrospinalis and laterally by the posterior border of the internal oblique. Primary lumbar hernias are very rare with only 300 cases reported. More commonly lumbar hernias are secondary to renal operations, when extensive incisional sacs may be present.

Differential diagnosis. A lumbar hernia must be distinguished from

lipoma;

  • a cold abscess pointing to this position;

  • phantom hernia due to local muscular paralysis. Lumbar phantom hernia can result from any interference with the nerve supply of the affected muscles (e.g. poliomyelitis).

Treatment. A primary lumbar hernia, being small, is easily repaired. As the natural history is for these hernias to increase in size with time, any primary lumbar hernia should be repaired at presentation. Incisional lumbar hernias may be large and the defect is impossible to repair unless fascial flaps are used. The repair can be reinforced with a sheet of polypropylene mesh.

Perineal hernia. This type of hernia is very rare. Varieties include:

 postoperative hernia through a perineal scar may occur after excision of the rectum;

median sliding perineal hernia is a complete prolapse of the rectum (Chapter 60);

 anterolateral perineal hernia occurs in women and presents as a swelling of the labum majus;

  posterolateral perineal hernia, which passes through the levator ani to enter the ischiorectal fossa.

Treatment. A combined operation is generally the most satisfactory for the last two types of hernia. The hernia is exposed by an incision directly over it. The sac is opened and its contents are reduced. The sac is cleared from surrounding structures and the wound closed. With the patients in semi-Trendelenburg position, the abdomen is opened and the mouth of the sac is exposed. The sac is inverted, ligated and excised and the pelvic floor repaired by muscle apposition and, if indicated, buttressing of the repair with prosthetic mesh.

Obturator hernia. The hernia, which passes through the obturator canal, occurs six times more frequently in women than in men. Most of the patients are over 60 years of age. The swelling is liable to be overlooked because it is covered by the pectineus. It seldom causes a definite swelling in Scarpa’s triangle, but if the limb is flexed, abducted and rotated outwards, sometimes the hernia becomes more apparent. The leg is usually kept in a semiflexed position and movement increases the pain. In more than 50 per cent of cases of strangulated obturator hernia, pain is referred along the obturator nerve by its geniculate branch to the knee. On vaginal or rectal examination the hernia sometimes can be felt as a tender swelling in the region of the obturator foramen.

Cases of obturator hernia which present themselves have usually undergone strangulation, which is frequently of the Richter type.

Treatment. Treatment consists of the following:

perform lower laparotomy (on the side of the lesion, if known). Confirm the diagnosis and then adopt full Trendelenburg’s position;

the constricting agent is the obturator fascia. Taking every precaution to avoid spilling infected fluid from the hernial sac into the peritoneal cavity, this fascia can be stretched to allow reduction by inserting suitable forceps through the gap in the fascia and opening the blades with care. If incision of the fascia is required, it should be made parallel to the obturator vessels and nerve;

the contents of the sac are dealt with;

the broad ligament is stitched over the opening to prevent recurrence.

Gluteal and sciatic hernias. A gluteal hernia passes through the greater sciatic foramen, either above or below the piriformis. A sciatic hernia passes through the lesser sciatic foramen. Differential diagnosis must be made between these conditions and:

a lipoma or fibrosarcoma beneath the gluteus maximus;

a tuberculous abscess;

a gluteal aneurysm.

All doubtful swellings in this situation should be explored by operation.