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Adult Groin Hernias: Acute and Elective
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the spermatic cord from the deep inguinal ring to the superficial inguinal ring along the inguinal canal. Inguinal hernias occur in this upper portion either as an ‘indirect’ or ‘direct’ hernia. The lower portion of the MPO allows the passage of the femoral vessels laterally and, in the case of herniation, a femoral hernia. As the embryological testicle descends towards the scrotum, an outpouching (‘sac’) of peritoneum extends downwards anteriorly: the processus vaginalis. This usually becomes obliterated at the deep inguinal ring with its remnant covering the testicle as the tunica vaginalis. If the process of obliteration is incomplete along this line of descent, a communication exists between the sac and the peritoneal cavity: a primary indirect inguinal hernia.
Adult Groin Hernias: Acute and Elective Michael Nelson Brian M Stephenson
In England and Wales, approximately 105,000 people develop inguinal hernias each year, with 10 elective repairs per 10,000 population carried in the UK. The number of inguinal hernia repairs performed in NHS hospitals in England and Wales in 1998/9 was 76,087, of which about 8% were for recurrence. The science of groin herniorrhaphy has evolved greatly over the last twenty years. Since Bassini’s pioneering work in 1887, there have been many developments by surgeons such as Halsted, McVay, Moloney and Shouldice. Their aim was to teach the principles of repair in the hope that the average surgeon might attain acceptable recurrence rates.
Why use prosthetic material in groin hernia repair? Since Bassini’s contribution to our understanding of the transversalis fascia, surgeons have sought to bridge the gap through which hernias occur. Over one hundred years ago, silver wire coils and filigrees were used, followed by stainless steel and tantalum meshes. In 1948, Maloney described the ‘darn’ using nylon suture material as a weave to create a tension-free lattice. More recently, polyester (Dacron/Mersilene) and polyethylene, preformed meshes have been used, but the most suitable nonabsorbable mesh is made of polypropylene. Since tension-free hernia repair is the ideal, the chosen synthetic material must have a number of requisite features. The mesh must be well tolerated, with little chance of rejection, and should be of a monofilament nature to avoid infection and sinus formation. In addition, the mesh must show a degree of fixity to the tissues following a prompt fibroblastic response. Subsequent host incorporation forms a strong fibrous wall. Both animal experiments and clinical evidence suggest that polypropylene mesh best meets these criteria.
Anatomical considerations The groin is one of the weakest points of the anterior abdominal wall and is the most common site for hernias. Prior to the widespread use of laparoscopy, some hernia specialists stated that the anatomy of the inguinal region was misunderstood, as many surgeons appreciated only the anatomy from an anterior view. The anatomy of the posterior aspect is now better understood with the detail afforded by laparoscopy. For more detailed information regarding anatomy of the groin, see Mahadevan, page 25. The anterior abdominal wall is formed by three flat muscles (external and internal obliques and the transversus abdominis) and their aponeuroses. The transversalis fascia covers the deepest surface of the transversus muscle, separating it from the underlying peritoneum. Between these two lies the preperitoneal (synonymous with properitoneal, see Mahadevan, page 25) space, which can be recognized by the glistening yellow fat that it contains. To allow the transmission from the abdominal cavity of the spermatic cord in men and the round ligament in women and the vessels of the lower limb, there must be a window for their passage. Inguinofemoral herniation occurs through such an aperture. The aperture is an oval-shaped portal—the myopectineal orifice (MPO)—in the lower anterior abdominal wall at its junction with the pelvis. The upper portion of the MPO allows the passage of
Anaesthesia for hernia repair All types of groin hernia can be repaired under general anaesthesia, but do we really need to subject all our patients to this approach? In some emergency cases a general anaesthetic will be necessary, especially if bowel resection is thought likely. In the elective situation, a spinal anaesthetic is an easy option but, as the anaesthetic is very intense, the incidence of urinary retention is relatively high, and a ‘spinal headache’ is an unwanted side-effect. With an epidural, the incidence of urinary retention is all but zero, and there is little in the way of the profound motor blockade of spinals. Given our increasing elderly population with their concurrent medical problems, surgeons should be able to offer a repair under a local anaesthetic. Its advantages include safety, simplicity, ontable assessment of the repair, earlier mobilization and a reduced hospital stay, although it may not be suitable in the obese. When repairing inguinal hernias under a local anaesthetic, the following points are important: • An appropriate solution is a mixture of 1% lignocaine (rapid onset) and 0.5% bupivacaine (long duration) with adrenaline (1:100,000). Draw-up two 20 ml syringes, each containing 10 ml of each. The average usage is 30–35 ml. • Mark line of proposed incision with medial end over pubic tubercle. • Administer both intracutaneous and subcutaneous injections along this line.
Michael Nelson quailified from the University Hospital of Wales, Cardiff, UK, and is undertaking the All Wales Training Scheme in General Surgery. His main interest is in colorectal surgery. Brian M Stephenson is a Consultant General and Colorectal Surgeon at the Royal Gwent Hospital, Newport, UK. He qualified from St Bartholomew’s Hospital, London, UK, and trained in general surgery in South Africa and Wales. He was a Research Fellow at the ICRF Colorectal Unit, Leeds, UK, and a Senior Registrar at St Mark’s Hospital, London, UK. His research interests include groin hernia and colorectal surgery.
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• Make deep vertical injections (1–2 ml) at right angles every 1–2 cm along the incision into the deeper subcutaneous tissues. • When the external oblique aponeurosis is exposed, inject a good volume (about 10 ml) deep to this, in order to flood and anaesthetize the 3 nerves contained within the canal. • Add more local solution when the patient complains of discomfort (e.g. when dissecting over the pubis or at the base of an indirect sac). • Splash any remaining local anaesthetic into the wound as you close. 1 A trimmed mesh is held in place with a continuous suture along the inguinal ligament and its lateral tails accommodate the spermatic cord. (The orange area represents the pubic tubercle).
Inguinal hernias and their repair Adult inguinal hernias appear as a lump in the groin and have a cough impulse unless they are irreducible. Indirect hernias can be asymptomatic, but usually cause some degree of discomfort. Direct hernias are rarely painful and patients may notice only a small swelling. The incidence of occult, bilateral (often direct) inguinal hernias may be 20–30%. The differential diagnosis includes inguinal lymphadenopathy (primary or secondary), a muscle haematoma and a lipoma or cystic hydrocele of the cord. A definitive diagnosis of these last two possibilities is often made only at operation. Pure ‘tissue’ repairs (Bassini, Shouldice, McVay, Maloney) give rise to tension along the suture lines. Whilst 'hernia specialists' obtained excellent results with these repairs, general surgeons did not. In recent years, the use of prosthetic mesh has gained in popularity and these repairs are described below.
the pubic tubercle and that the stitch bites into tissue over the pubic bone rather than the periosteum. The stitch is then continued laterally along the lower edge of the mesh and the inguinal ligament to just beyond the deep ring. At this stage the lateral end of the mesh is cut to create two tails and the larger upper one is pulled beneath the cord and then placed lateral to the cord. The upper portion of the mesh is then sutured to the internal oblique muscle with 3 or 4 loose absorbable sutures. Finally, the upper tail is sutured to the lower tail and to the inguinal ligament creating a ‘new’ deep ring for the spermatic cord. It is important to ensure that the mesh is applied loosely (rather than tight and ‘smooth-looking’) as this pulls when the patient strains, coughs or stands. Recurrent inguinal hernia repair is a challenging problem. In addition, even when the operative notes of the previous repair are available, the anatomy is often distorted. For recurrent inguinal hernias, two approaches are recommended by Lichtenstein et al. Fortunately the majority of recurrences (>80%) are small (<3 cm) direct hernias or an indirect recurrence (possibly missed at the earlier repair). In an attempt to minimize the chance of damage to the nerves and cord structures of the inguinal canal, the dissection is aimed directly at the hernial sac and defect. Once the margins of the defect are defined and the sac reduced, the defect is ‘plugged’ with a solid plug of mesh, anchored with several non-absorbable sutures to its edges. No further action is taken unless the defect is very large, when the repair progresses as for a primary inguinal hernioplasty.
‘Lichtenstein’ repair: Lichtenstein et al from Los Angeles, USA, were the first to popularize the use of mesh on the grounds that sutured repairs (Bassini and Shouldice) led to unavoidable tension on the suture line. An oblique 6–8 cm incision is deepened down to the external oblique aponeurosis (EOA) and this is opened in the direction of its fibres with care to expose and avoid injuring the underlying ilioinguinal nerve. The EOA is opened from the pubic tubercle to the deep inguinal ring as two leaves. The spermatic cord is gently freed, avoiding damage to the external spermatic or cremasteric vessels which are very friable. The upper leaf of the EOA is cleared from the underlying internal oblique muscle in an attempt to identify the iliohypogastric nerve. An indirect sac is identified by thinning the cremasteric muscle fibres at the lateral end of the cord. The sac should be separated from the cord structures and be replaced into the peritoneal cavity. The sac should not be ligated or excised, as this leads to further pain. When dealing with a sliding hernia, it is often better to avoid opening the sac at all, as the underlying bowel or bladder is liable to damage. In an inguinoscrotal hernia, the sac can be transected and the distal portion left in situ so as to minimize damage to the cord structures. When dealing with a direct hernia, especially if the defect is wide and occupies most of the posterior wall, it should be held reduced with a purse-string or inverting suture. As the mesh prosthesis is supplied as a flat piece (about 8 x 15 cm), it is necessary to prepare it by trimming and later creating lateral tails. The cord is retracted, allowing placement of the first non-absorbable suture above and medial to the pubic tubercle (Figure 1). One must ensure adequate mesh coverage medial to
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‘Plug and patch’ repair: the Lichtenstein hernia repair relies on the strength and proper placement of the prosthetic mesh. The hernial defect per se in primary hernias (indirect or direct) is not addressed as the underlying problem. However, when dealing with a recurrent hernia, the dissection could certainly be described as ‘minimalist’. This minimalist approach was further exploited by Rutkow in New Jersey, USA, who was the first to describe the plug and patch technique which, from an anatomical viewpoint, is a preperitoneal repair via an anterior incision. In this repair, the dissection is aimed directly at the hernial defect. In an indirect hernia, the sac is dissected free from the cord until preperitoneal fat is seen, indicating that a relatively high dissection has been achieved, and the sac can be replaced through the deep ring. This allows the edges of the defect to be defined and the aperture to be plugged with a preformed mesh plug that
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comes in four sizes. The periphery of the plug is sutured to the edges of the ring with 3 or 4 loose absorbable sutures. Generally, indirect hernias require a medium or large plug. In a direct hernia (Figure 2), the sac is separated from the cord, and the thin, attenuated transversalis fascia circumscribed just short of its base until the glistening preperitoneal fat is reached. A plug (usually large) is then located in the defect and held in place with absorbable sutures placed around its circumference. Thus, the defect of either an indirect or direct (or recurrent) hernia is addressed in a similar fashion. In addition to plugging the defect, an ‘onlay’ patch (about 4 x 9 cm) is placed (but not sutured) so as to cover the posterior wall of the canal. This onlay patch is not an integral part of the repair, but merely acts as a form of prophylaxis, and as such need not be sutured. It is intended solely to strengthen the posterior wall in an indirect repair and strengthen the area of the deep ring in a direct repair. The repair is completed with closure of the lateral tails over the cord. The dissection using this approach is technically simple and is certainly minimalist, leading to lower postoperative discomfort and complications. In addition, the plug can be used in femoral hernia repair (see below).
with an oval onlay (Figure 3) patch and comes in three sizes. The dissection for indirect inguinal hernias is as before, but the surgeon is encouraged to bluntly dissect in the preperitoneal plane at the level of the deep ring to enlarge this space so that the underlay patch can be positioned behind the posterior wall. In direct hernias, as for the plug and patch repair, the defect is circumscribed at its base to allow positioning of the underlay patch. In both types of hernia repair, the onlay patch is slit (either centrally or laterally) to accommodate the spermatic cord and then anchored at numerous points with sutures to ensure immobility. Although we have used this device, we feel that this approach involves a fair amount of dissection, much of it blunt. Whilst this technique probably has a niche in the management of large direct and recurrent inguinal hernias, the size of the connector (about 2 cm) makes it difficult to place in the smaller primary indirect hernias. The results of further reports with the PHS (a relatively new repair) are awaited. Closure: in all of the above repairs, the wound is closed in layers (continuous absorbable to EOA, interrupted to subcutaneous tissues); once the patient is comfortable and has passed urine, he can be discharged. The patient should be encouraged to take physical activity and return to work as soon as possible. Return to normality does not lead to recurrence, and the use of mesh per se does not guarantee a permanently secure repair. How the individual operation is performed is much more important.
‘Bilayer’ repair: Gilbert, from Miami, USA, believes that the inguinal canal deserves to be protected with mesh placed over both sides of the myopectineal orifice. The Prolene Hernia System® (PHS) comprises a circular underlay portion of mesh connected
Lararoscopic repairs: laparoscopic techniques allow groin hernia repair to be undertaken without opening the anterior abdominal wall, but they all require general anaesthesia. As with open repairs, a piece of mesh is used to cover the hernial defect in the preperitoneal plane after dealing with the sac and its contents. Laparoscopic hernia repair was first described in 1982, and there are two main approaches. The transabdominal preperitoneal (TAPP) repair involves entry into the abdominal cavity in the usual fashion, and the hernia reduced under direct vision. The neck of the hernial sac is then excised, allowing entry to the preperitoneal plane where further dissection creates a pocket in which the mesh will be placed. In indirect hernias, the internal (deep) ring is closed with sutures, and in a direct defect, the transversalis fascia is plicated with a continous suture. In both types, a large sheet of polypropylene mesh (about 11 x 11 cm) is used to cover the site of the hernia and the back wall of the inguinal canal. The mesh is either stapled or sutured in place, and then the overlying previously created peritoneal defect must be closed meticulously to avoid internal herniation, a complication which has probably relegated this repair to ‘second-best’ when compared to the totally extraperitoneal (TEP) technique. In the TEP approach, both insufflation, repair and mesh placement are performed in the preperitoneal plane, with or without the aid of a balloon dissection device (Figure 4). Whilst TEP repairs are technically much more challenging than TAPPs (especially when dealing with large indirect hernias) major complications are less frequent and small bowel obstruction most unlikely as the peritoneal cavity is not violated. Despite this hurdle, recent data suggest that TEP repairs are now more commonly performed than TAPP repairs.
a
b
c
The size of the direct hernia a is appreciated when the patient coughs b. The defect in the transversalis fascia has been plugged c.
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Femoral hernias and their repair Femoral hernias account for less than 10% of groin hernias, but may account for up to a third of strangulated hernias. Anatomical considerations and diagnosis: The borders of the femoral canal is about 2 cm in length and runs from the femoral ring to femoral orifice, and can be easily identified. As the peritoneal sac of a femoral hernia enlarges and pushes its way through the normally closed distal end of the canal, it becomes trapped. The canal is bound anteriorly by the inguinal liagament, with its lacunar extension forming the medial wall, and posteriorly is the pectineus muscle/fascia and superior ramus of the pubis. The lateral border of the canal is formed by the femoral vein itself. Rarely, instead of passing down the femoral canal, the hernia lies more laterally, either superficial (so-called prevascular) or deep to the vessels entering the leg. On clinical examination, a femoral hernia is below and lateral to the pubic tubercle and only rarely is there a cough impulse. In the elective situation, the differential diagnosis of femoral herniation includes a lymph node and saphena varix, but it must be emphasized that femoral hernias should be considered when one ponders the cause of a patient’s intestinal (small bowel) obstruction. There are several ways in which a femoral hernia can be repaired and each approach has its merits.
3 The bilayer Prolene Hernia System® (PHS).
The plane of dissection for TEP repairs Subcutaneous tissue
Rectus abdominis muscle
Peritoneal cavity
Peritoneum
How a TAPP approach converts an extraperitoneal operation into an intraperitoneal operation a TEP
Pubic symphysis
TAPP
Peritoneal cavity Umbilicus b
Peritoneum
Femoral hernia: the opened sac a and the defect defined b. 4 SURGERY
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Low approach: the hernial sac is exposed via a low 5 cm groin incision, cleared of the overlying preperitoneal fat, and opened (Figure 5a). The sac is opened to inspect the contents and, in the emergency situation, to check for blood-stained fluid which may indicate bowel ischaemia. The sac is then excised and transfixed and the edges of the defect further clarified (Figure 5b). Traditionally, the defect was closed by loosely approximating the undersurface of the inguinal ligament to Cooper’s ligament with a non-absorbable stitch in an ‘X’ or ‘N’ fashion to form a lattice. This repair can be further reinforced by mobilizing a strip of pectineus fascia, folding it upwards on itself, and stitching it to the inguinal ligament. Care must be taken to protect the femoral vein. Femoral hernias can also be plugged with mesh either as a solid plug or with a preformed mesh plug. These plugs are secured to the adjacent tissues with four or five interrupted nonabsorbable sutures. This approach is safe and quite satisfactory for the vast majority of femoral hernias, but if ischaemic bowel is encountered (e.g. Richter’s hernia) the exposure obtained makes the situation difficult to deal with.
was performed for strangulation. The diagnosis is rarely in doubt as the hernia is tender and there are local signs (e.g. inflammation) and there may be systemic upset (e.g. tachycardia). In an incarcerated inguinal hernia, gentle taxis may allow the hernia to be reduced. This should not be attempted in a femoral hernia as it may cause further damage to the bowel. There may be symptoms and signs of intestinal obstruction and careful attention needs to be paid to the resuscitation of the patient with intravenous fluids and antibiotics. Not all inguinal hernias are at equal risk of strangulation and, whilst irreducible hernias are at higher risk, only 10% of patients operated on for strangulation give a history of preceding herniation. In general, indirect hernias are 10 times more likely to strangulate than direct hernias. Overall, the annual probability of strangulation appears to be between 0.3% and 3%. Recurrent inguinal hernias are probably also at increased risk of strangulation, but the magnitude of the problem is much more difficult to quantify. The anatomy of the femoral canal, with its narrow neck and unyielding boundaries, accounts for the fact that the proportion of femoral hernias presenting with strangulation may be as high as 50%, although recent audits have reported much lower figures. The need for resection for irreversible bowel ischaemia is twice as high in strangulated femoral hernias as in inguinal hernias.
Transinguinal approach: the floor of the inguinal canal (transversalis fascia) can be opened to allow reduction of the sac of the femoral hernia. When the margins are clearly defined, Cooper’s ligament is then directly sutured to the iliopubic tract. Another technique is to obliterate the space with a portion of mesh that can then be continued as an inguinal hernioplasty. This technique has few merits and predisposes the patient to a later direct inguinal hernia.
Complications of groin hernia repair Wound problems: postoperative problems such as bruising and haematoma are not infrequent if repairs are carried out under local anaesthesia, and patients should be warned of this possibility. Careful attention to technique and meticulous haemostasis are important. Wound infection, which predisposes to recurrence, may occur in 1–2% of patients, and although there is no firm evidence for routine antibiotic prophylaxis, we give all adults a single dose of amoxicillin. The inplantation of mesh in hernia repairs leads to an inflammatory process and the development of a seroma which can be detected by ultrasound within a few days of the operation. This is usually a self-limiting process, but large seromas may need to be aspirated. When repeated aspirations are necessary, it is important to consider the possibility of underlying mesh sepsis, but this is an uncommon problem.
High/preperitoneal approach: bowel resection can be readily performed when the hernial sac is uncovered via the preperitoneal approach. The abdominal incision can be a midline (Henry), pararectus (McEvedy), Pfannenstiel or transverse suprainguinal muscle-splitting (Nyhus), but the sac is exposed only when the peritoneum is reflected from the posterior lower abdominal wall. If there is difficulty in reducing the hernia, the peritoneal cavity can be conveniently entered above the incarcerated hernia. The hernial defect can be repaired either with sutures, or a flat piece of mesh to cover the lower portions of the MPO as in a TEP repair. This approach, whilst giving good access, seems excessive in elective cases and we reserve it for the acute case in which we consider resection highly likely. An incarcerated hernia can be explored under local anaesthetic, and the operation later converted to a preperitoneal approach, with a general anaesthetic, if the operative findings so dictate.
Scrotal problems: penile and scrotal oedema is not uncommon and certainly more frequent after the repair of large or bilateral hernias. Ischaemic orchitis and testicular atrophy is said to occur in 0.5–3% of men, and is possibly due to venous congestion (from surgical trauma) rather than from primary arterial damage. Gentle dissection and cord mobilization can minimize its incidence. In addition, it is important to avoid the temptation to deliver the testicle into the wound when operating on an inguinoscrotal hernia. The formation of a hydrocele can also occur when the distal sac of a large hernia is left in situ. The accumulation of this fluid can be prevented by dividing the sac anteriorly along its length.
Laparoscopic approach: the repair of femoral hernias, both elective and acute, has been performed laparoscopically. The operation is similar to that for inguinal hernia repair in that either a TAPP or TEP approach is feasible. The TEP technique is preferred, but it is hard to justify the risk and expense when far less complex alternatives are readily available and can be performed under locoregional anaesthesia. The incarcerated/strangulated groin hernia The incidence of strangulation is an important issue given the accompanying postoperative mortality, especially in the elderly. The Confidential Enquiry into Perioperative Deaths (CEPOD) suggested an overall mortality of about 7% when emergency surgery
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Specific problems: there is a great deal of overlap in the cutaneous areas supplied by the iliohypogastric (L1) and ilioinguinal (L1) nerves and the sensory branches of the genitofemoral nerve (L2). Although patients may have a variable area of skin anaes-
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thesia after operation, it generally returns to normal within a few months and is of little functional consequence. This is in contrast to persistent postoperative pain that is an increasingly recognized problem. Causes include adductor strain, osteitis pubis and neuralgia, with or without neuroma formation. Such patients are best managed with a multidisciplinary approach including specialist pain teams. The femoral artery may be more superficial than imagined, and be at increased risk in thin patients. In femoral hernia repair, the vein may be damaged, but problems such as oedema and deep vein thrombosis may not be apparent for some time after operation, especially if a sutured repair was overly tight.
Guidelines for the urgency of groin hernia repair • Indirect and symptomatic direct inguinal hernias should be repaired to relieve symptoms and eliminate the small risk of strangulation • Small, easily reducible, direct inguinal hernias can be safely left alone as the risk of strangulation is very small • Irreducible hernias and those with a short history should be repaired sooner rather than later • All femoral hernias should be repaired urgently 6
Complications of laparoscopic hernioplasty: all the complications seen after open groin hernia repair are also seen after laparoscopic hernioplasty, but some are unique and specific to this approach. Apart from the complications from general anaesthesia, vascular, bowel and bladder injury may occur during the creation of the pneumoperitoneum, as required in TAPPs. Small bowel obstruction, due to entrapment in peritoneal defects (after TAPP) and trocar site herniation is seen in 1–2% of repairs. Whilst neural injuries can be seen after open repair, damage to the lateral femoral cutaneous nerve (L2, L3) is unique to laparoscopic repairs. Wound seromas can occur in up to 7% of preperitoneal (TEP) repairs, but most resolve within 6–8 weeks of surgery.
Glossary Inguinal canal Passes obliquely through the anterior abdominal wall from the deep to the superficial ring. The posterior wall of the canal is the transversalis fascia. In the male it contains the structures which make up the spermatic cord: 3 arteries (testicular, cremasteric and to the vas), 3 nerves (ilioinguinal, genital branch of genitofemoral and sympathetics) and 3 other structures (vas deferens, pampiniform plexus of veins and remnants of the processus vaginalis).
Results of inguinal hernia repair in the modern era When considering recurrence, it is important that there is a long period of follow-up as 50% of recurrences do not appear for five or more years after the initial operation, and 20% may not be apparent for 15–25 years! Recurrence occurring in the first few years is probably due to technical failure (technique, tension, missed hernia, infection). Thereafter, tissue weakness/failure, and a later, acquired hernia are more likely causes for the ‘recurrence’. Thus, a follow-up of ten years would seem the minimum required in order to quote a repair’s ‘true’ recurrence rate. From the literature, it appears that ‘general’ surgeons may have recurrence rates of 5–10%, whilst more dedicated surgeons have rates of between 1 and 2%, and published hernia ‘zealots’ rates of <1%. Indeed, all the repairs described above have published series with recurrence rates of <1%. The real challenge now is for the general surgeon to attain rates of less than 1–2% and, with this in mind, the surgeon must choose the repair he/she is most comfortable with. Thus, when comparing recurrence rates, it is prudent to recall the thoughts of Kirk who, in 1983, wrote: ‘In my experience, outstanding and thoughtful surgeons who devise new techniques attribute their success to the method. They are too modest. Their colleagues know that it is not the particular method that brings success, but the enthusiasm for perfection and painstaking skill with which it is accomplished.’
Indirect inguinal hernia Passes through the deep inguinal ring and extends down the canal towards the scrotum. The sac is lateral to the inferior epigastric vessels. If it passes into the scrotum, it is described as inguinoscrotal. Indirect hernias are twice as common as ‘direct’ ones. Sliding hernia Occurs when a viscus (often sigmoid colon or caecum), or its mesentery forms one of the walls of the hernial sac. Occurs in about 5% of hernias and more common in the elderly. It is very rare for there to be a sliding component in direct or femoral hernias. Direct inguinal hernia Is one that is due to a weakened transversalis fascia in Hesselbach’s triangle. It is most unusual for the sac to pass into the scrotum. They are common in the obese and elderly and are often bilateral, but rarely incarcerate as the neck is wide. Femoral hernia Is one that comes through the femoral canal medial to the femoral vein. As its neck is narrow it is more likely to strangulate than an inguinal hernia. Incarcerated hernia If the contents of a hernial sac become entrapped, the hernia is said to be irreducible or incarcerated.
Open tension-free or laparoscopic groin hernia repair? Laparoscopic cholecystectomy has many advantages for the patient, hospital and employer when compared to the open procedure. However, is this true when comparing laparoscopic and open tension-free inguinal hernioplasty? Laparoscopic surgeons claim there is less postoperative pain and earlier return to full activity, but the overall picture is not that simple, as we know these end-points are quite subjective, irrespective of whether
Strangulated hernia If the blood flow to the viscus in an incarcerated hernia becomes compromised, the hernia is described as strangulated, and if not reduced/repaired, necrosis and perforation will follow. 7
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the patient is motivated or not. Furthermore, laparoscopic repair is certainly not suitable for all patients with a symptomatic hernia. In a recent MRC randomized trial, over 40% of identified patients were excluded because they were unfit, had large or difficult hernias, or had had previous abdominal surgery. In addition, laparoscopy incurs extra costs (theatre time, laparoscopic equipment), and it has been estimated that a laparoscopic repair has an additional UK NHS cost of about £300 per procedure. Furthermore, given the higher intraoperative risks (after TAPP), and probable higher rates of recurrence with longer follow-up, there seems little to recommend its widespread use. In addition, many experienced surgeons find the repair awkward and timeconsuming. If the difference in outcome was real, the last decade would have seen the numbers of laparoscopic repairs rising but, to date, less than 5–10% of repairs in the UK are performed in this manner. The UK NHS National Institute for Clinical Excellence (NICE) has recently appraised the role of laparoscopic surgery in inguinal hernia repair and has suggested the following tailored approach: • primary inguinal hernias should be repaired with an open mesh technique. • recurrent and bilateral hernias may be repaired laparoscopically (TEP approach) in units with appropriately trained teams who regularly undertake these procedures. Guidelines for the urgency of groin hernia repair and a glossary of terms are described in Figures 6 and 7 respectively. u
Inflammatory Bowel Disease Charles Maxwell-Armstrong Richard Cohen
The term ‘inflammatory bowel disease’ (IBD) includes ulcerative colitis (UC) and Crohn’s disease (CD), as well as cases of indeterminate colitis, where the patient may show features of both. UC is an inflammatory disorder affecting the colon, typically extending proximally from the rectum. The terminal ileum is not involved, except in cases of total colitis, where there may be a ‘backwash’ ileitis, where the ileum becomes inflamed due to an incompetent ileocaecal valve. CD affects any part of the bowel from mouth to anus, occasionally involving discontinuous discrete areas: ‘skip lesions’.
Epidemiology In the UK, the prevalence of IBD is 5.12/1000 at age 43 years, and 2.02–2.54/1000 by age 33 years. The figures for the incidence of UC vary between 2.6 and 15.1 cases per 100,000 people per annum, with corresponding figures of 0.7 to 6.6 for CD. Recent studies in children have found the incidence of IBD to be 5.2/ 100,000 children per year, substantially greater than the figure of 2.2 reported in the mid-1980s. It is important that figures suggesting an increase in IBD are interpreted with caution as there may be variations in data collection, reporting, and confusion with cases that were probably infective.
FURTHER READING Bay-Nielsen M, Kehlet H, Strand L et al. Quality assessment of 26,304 herniorrhaphies in Denmark: a prospective nationwide study. Lancet 2001; 358(9288): 1124–8. Guidance on the Use of Laparoscopic Surgery for Inguinal Hernia. London: NHS National Institute for Clinical Excellence (NICE), 2001. The MRC Laparoscopic Groin Hernia Trial Group. Laparoscopic versus open repair of groin hernia: a randomised comparison. Lancet 1999; 354 (9174): 185–90. Vrijland W W, van den Tol M P, Luijendijk R W et al. Randomized clinical trial of non-mesh versus mesh repair of primary inguinal hernia. Br J Surg 2002; 89(3): 293–7.
Pathology The macroscopic appearance of UC varies according to disease severity, ranging from mild serosal injection, to more severe inflammatory change (Figure 1), with colonic distension, and wall thinning (in cases of toxic megacolon). Healed, chronic colitis may also have a characteristic ‘scarred’ picture at colonoscopy (Figure 2). Microscopically, there is initially an acute inflammatory response, characterized by neutrophil, plasma cell and eosinophil infiltration. This is not transmural, and involves the lamina propria. More chronic changes include the formation of crypt abscesses, and disturbances in crypt architecture. CD macroscopically may be characterized by a number of features including, fistulas (Figure 3), from bowel to any or all of skin, bladder, vagina, and other areas of intestine. The bowel may be thickened, and strictured, with characteristic ‘fat wrapping’. Unlike UC, CD shows a transmucosal infiltrate and granulomas, usually containing giant cells.
Charles Maxwell-Armstrong is a Consultant Surgeon at University Hospital, Nottingham, UK. Richard Cohen is a Consultant Colorectal Surgeon at St Mark’s Hospital and Central Middlesex Hospital, London, UK.
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the spermatic cord from the deep inguinal ring to the superficial inguinal ring along the inguinal canal. Inguinal hernias occur in this upper portion either as an ‘indirect’ or ‘direct’ hernia. The lower portion of the MPO allows the passage of the femoral vessels laterally and, in the case of herniation, a femoral hernia. As the embryological testicle descends towards the scrotum, an outpouching (‘sac’) of peritoneum extends downwards anteriorly: the processus vaginalis. This usually becomes obliterated at the deep inguinal ring with its remnant covering the testicle as the tunica vaginalis. If the process of obliteration is incomplete along this line of descent, a communication exists between the sac and the peritoneal cavity: a primary indirect inguinal hernia.
Adult Groin Hernias: Acute and Elective Michael Nelson Brian M Stephenson
In England and Wales, approximately 105,000 people develop inguinal hernias each year, with 10 elective repairs per 10,000 population carried in the UK. The number of inguinal hernia repairs performed in NHS hospitals in England and Wales in 1998/9 was 76,087, of which about 8% were for recurrence. The science of groin herniorrhaphy has evolved greatly over the last twenty years. Since Bassini’s pioneering work in 1887, there have been many developments by surgeons such as Halsted, McVay, Moloney and Shouldice. Their aim was to teach the principles of repair in the hope that the average surgeon might attain acceptable recurrence rates.
Why use prosthetic material in groin hernia repair? Since Bassini’s contribution to our understanding of the transversalis fascia, surgeons have sought to bridge the gap through which hernias occur. Over one hundred years ago, silver wire coils and filigrees were used, followed by stainless steel and tantalum meshes. In 1948, Maloney described the ‘darn’ using nylon suture material as a weave to create a tension-free lattice. More recently, polyester (Dacron/Mersilene) and polyethylene, preformed meshes have been used, but the most suitable nonabsorbable mesh is made of polypropylene. Since tension-free hernia repair is the ideal, the chosen synthetic material must have a number of requisite features. The mesh must be well tolerated, with little chance of rejection, and should be of a monofilament nature to avoid infection and sinus formation. In addition, the mesh must show a degree of fixity to the tissues following a prompt fibroblastic response. Subsequent host incorporation forms a strong fibrous wall. Both animal experiments and clinical evidence suggest that polypropylene mesh best meets these criteria.
Anatomical considerations The groin is one of the weakest points of the anterior abdominal wall and is the most common site for hernias. Prior to the widespread use of laparoscopy, some hernia specialists stated that the anatomy of the inguinal region was misunderstood, as many surgeons appreciated only the anatomy from an anterior view. The anatomy of the posterior aspect is now better understood with the detail afforded by laparoscopy. For more detailed information regarding anatomy of the groin, see Mahadevan, page 25. The anterior abdominal wall is formed by three flat muscles (external and internal obliques and the transversus abdominis) and their aponeuroses. The transversalis fascia covers the deepest surface of the transversus muscle, separating it from the underlying peritoneum. Between these two lies the preperitoneal (synonymous with properitoneal, see Mahadevan, page 25) space, which can be recognized by the glistening yellow fat that it contains. To allow the transmission from the abdominal cavity of the spermatic cord in men and the round ligament in women and the vessels of the lower limb, there must be a window for their passage. Inguinofemoral herniation occurs through such an aperture. The aperture is an oval-shaped portal—the myopectineal orifice (MPO)—in the lower anterior abdominal wall at its junction with the pelvis. The upper portion of the MPO allows the passage of
Anaesthesia for hernia repair All types of groin hernia can be repaired under general anaesthesia, but do we really need to subject all our patients to this approach? In some emergency cases a general anaesthetic will be necessary, especially if bowel resection is thought likely. In the elective situation, a spinal anaesthetic is an easy option but, as the anaesthetic is very intense, the incidence of urinary retention is relatively high, and a ‘spinal headache’ is an unwanted side-effect. With an epidural, the incidence of urinary retention is all but zero, and there is little in the way of the profound motor blockade of spinals. Given our increasing elderly population with their concurrent medical problems, surgeons should be able to offer a repair under a local anaesthetic. Its advantages include safety, simplicity, ontable assessment of the repair, earlier mobilization and a reduced hospital stay, although it may not be suitable in the obese. When repairing inguinal hernias under a local anaesthetic, the following points are important: • An appropriate solution is a mixture of 1% lignocaine (rapid onset) and 0.5% bupivacaine (long duration) with adrenaline (1:100,000). Draw-up two 20 ml syringes, each containing 10 ml of each. The average usage is 30–35 ml. • Mark line of proposed incision with medial end over pubic tubercle. • Administer both intracutaneous and subcutaneous injections along this line.
Michael Nelson quailified from the University Hospital of Wales, Cardiff, UK, and is undertaking the All Wales Training Scheme in General Surgery. His main interest is in colorectal surgery. Brian M Stephenson is a Consultant General and Colorectal Surgeon at the Royal Gwent Hospital, Newport, UK. He qualified from St Bartholomew’s Hospital, London, UK, and trained in general surgery in South Africa and Wales. He was a Research Fellow at the ICRF Colorectal Unit, Leeds, UK, and a Senior Registrar at St Mark’s Hospital, London, UK. His research interests include groin hernia and colorectal surgery.
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• Make deep vertical injections (1–2 ml) at right angles every 1–2 cm along the incision into the deeper subcutaneous tissues. • When the external oblique aponeurosis is exposed, inject a good volume (about 10 ml) deep to this, in order to flood and anaesthetize the 3 nerves contained within the canal. • Add more local solution when the patient complains of discomfort (e.g. when dissecting over the pubis or at the base of an indirect sac). • Splash any remaining local anaesthetic into the wound as you close. 1 A trimmed mesh is held in place with a continuous suture along the inguinal ligament and its lateral tails accommodate the spermatic cord. (The orange area represents the pubic tubercle).
Inguinal hernias and their repair Adult inguinal hernias appear as a lump in the groin and have a cough impulse unless they are irreducible. Indirect hernias can be asymptomatic, but usually cause some degree of discomfort. Direct hernias are rarely painful and patients may notice only a small swelling. The incidence of occult, bilateral (often direct) inguinal hernias may be 20–30%. The differential diagnosis includes inguinal lymphadenopathy (primary or secondary), a muscle haematoma and a lipoma or cystic hydrocele of the cord. A definitive diagnosis of these last two possibilities is often made only at operation. Pure ‘tissue’ repairs (Bassini, Shouldice, McVay, Maloney) give rise to tension along the suture lines. Whilst 'hernia specialists' obtained excellent results with these repairs, general surgeons did not. In recent years, the use of prosthetic mesh has gained in popularity and these repairs are described below.
the pubic tubercle and that the stitch bites into tissue over the pubic bone rather than the periosteum. The stitch is then continued laterally along the lower edge of the mesh and the inguinal ligament to just beyond the deep ring. At this stage the lateral end of the mesh is cut to create two tails and the larger upper one is pulled beneath the cord and then placed lateral to the cord. The upper portion of the mesh is then sutured to the internal oblique muscle with 3 or 4 loose absorbable sutures. Finally, the upper tail is sutured to the lower tail and to the inguinal ligament creating a ‘new’ deep ring for the spermatic cord. It is important to ensure that the mesh is applied loosely (rather than tight and ‘smooth-looking’) as this pulls when the patient strains, coughs or stands. Recurrent inguinal hernia repair is a challenging problem. In addition, even when the operative notes of the previous repair are available, the anatomy is often distorted. For recurrent inguinal hernias, two approaches are recommended by Lichtenstein et al. Fortunately the majority of recurrences (>80%) are small (<3 cm) direct hernias or an indirect recurrence (possibly missed at the earlier repair). In an attempt to minimize the chance of damage to the nerves and cord structures of the inguinal canal, the dissection is aimed directly at the hernial sac and defect. Once the margins of the defect are defined and the sac reduced, the defect is ‘plugged’ with a solid plug of mesh, anchored with several non-absorbable sutures to its edges. No further action is taken unless the defect is very large, when the repair progresses as for a primary inguinal hernioplasty.
‘Lichtenstein’ repair: Lichtenstein et al from Los Angeles, USA, were the first to popularize the use of mesh on the grounds that sutured repairs (Bassini and Shouldice) led to unavoidable tension on the suture line. An oblique 6–8 cm incision is deepened down to the external oblique aponeurosis (EOA) and this is opened in the direction of its fibres with care to expose and avoid injuring the underlying ilioinguinal nerve. The EOA is opened from the pubic tubercle to the deep inguinal ring as two leaves. The spermatic cord is gently freed, avoiding damage to the external spermatic or cremasteric vessels which are very friable. The upper leaf of the EOA is cleared from the underlying internal oblique muscle in an attempt to identify the iliohypogastric nerve. An indirect sac is identified by thinning the cremasteric muscle fibres at the lateral end of the cord. The sac should be separated from the cord structures and be replaced into the peritoneal cavity. The sac should not be ligated or excised, as this leads to further pain. When dealing with a sliding hernia, it is often better to avoid opening the sac at all, as the underlying bowel or bladder is liable to damage. In an inguinoscrotal hernia, the sac can be transected and the distal portion left in situ so as to minimize damage to the cord structures. When dealing with a direct hernia, especially if the defect is wide and occupies most of the posterior wall, it should be held reduced with a purse-string or inverting suture. As the mesh prosthesis is supplied as a flat piece (about 8 x 15 cm), it is necessary to prepare it by trimming and later creating lateral tails. The cord is retracted, allowing placement of the first non-absorbable suture above and medial to the pubic tubercle (Figure 1). One must ensure adequate mesh coverage medial to
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‘Plug and patch’ repair: the Lichtenstein hernia repair relies on the strength and proper placement of the prosthetic mesh. The hernial defect per se in primary hernias (indirect or direct) is not addressed as the underlying problem. However, when dealing with a recurrent hernia, the dissection could certainly be described as ‘minimalist’. This minimalist approach was further exploited by Rutkow in New Jersey, USA, who was the first to describe the plug and patch technique which, from an anatomical viewpoint, is a preperitoneal repair via an anterior incision. In this repair, the dissection is aimed directly at the hernial defect. In an indirect hernia, the sac is dissected free from the cord until preperitoneal fat is seen, indicating that a relatively high dissection has been achieved, and the sac can be replaced through the deep ring. This allows the edges of the defect to be defined and the aperture to be plugged with a preformed mesh plug that
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comes in four sizes. The periphery of the plug is sutured to the edges of the ring with 3 or 4 loose absorbable sutures. Generally, indirect hernias require a medium or large plug. In a direct hernia (Figure 2), the sac is separated from the cord, and the thin, attenuated transversalis fascia circumscribed just short of its base until the glistening preperitoneal fat is reached. A plug (usually large) is then located in the defect and held in place with absorbable sutures placed around its circumference. Thus, the defect of either an indirect or direct (or recurrent) hernia is addressed in a similar fashion. In addition to plugging the defect, an ‘onlay’ patch (about 4 x 9 cm) is placed (but not sutured) so as to cover the posterior wall of the canal. This onlay patch is not an integral part of the repair, but merely acts as a form of prophylaxis, and as such need not be sutured. It is intended solely to strengthen the posterior wall in an indirect repair and strengthen the area of the deep ring in a direct repair. The repair is completed with closure of the lateral tails over the cord. The dissection using this approach is technically simple and is certainly minimalist, leading to lower postoperative discomfort and complications. In addition, the plug can be used in femoral hernia repair (see below).
with an oval onlay (Figure 3) patch and comes in three sizes. The dissection for indirect inguinal hernias is as before, but the surgeon is encouraged to bluntly dissect in the preperitoneal plane at the level of the deep ring to enlarge this space so that the underlay patch can be positioned behind the posterior wall. In direct hernias, as for the plug and patch repair, the defect is circumscribed at its base to allow positioning of the underlay patch. In both types of hernia repair, the onlay patch is slit (either centrally or laterally) to accommodate the spermatic cord and then anchored at numerous points with sutures to ensure immobility. Although we have used this device, we feel that this approach involves a fair amount of dissection, much of it blunt. Whilst this technique probably has a niche in the management of large direct and recurrent inguinal hernias, the size of the connector (about 2 cm) makes it difficult to place in the smaller primary indirect hernias. The results of further reports with the PHS (a relatively new repair) are awaited. Closure: in all of the above repairs, the wound is closed in layers (continuous absorbable to EOA, interrupted to subcutaneous tissues); once the patient is comfortable and has passed urine, he can be discharged. The patient should be encouraged to take physical activity and return to work as soon as possible. Return to normality does not lead to recurrence, and the use of mesh per se does not guarantee a permanently secure repair. How the individual operation is performed is much more important.
‘Bilayer’ repair: Gilbert, from Miami, USA, believes that the inguinal canal deserves to be protected with mesh placed over both sides of the myopectineal orifice. The Prolene Hernia System® (PHS) comprises a circular underlay portion of mesh connected
Lararoscopic repairs: laparoscopic techniques allow groin hernia repair to be undertaken without opening the anterior abdominal wall, but they all require general anaesthesia. As with open repairs, a piece of mesh is used to cover the hernial defect in the preperitoneal plane after dealing with the sac and its contents. Laparoscopic hernia repair was first described in 1982, and there are two main approaches. The transabdominal preperitoneal (TAPP) repair involves entry into the abdominal cavity in the usual fashion, and the hernia reduced under direct vision. The neck of the hernial sac is then excised, allowing entry to the preperitoneal plane where further dissection creates a pocket in which the mesh will be placed. In indirect hernias, the internal (deep) ring is closed with sutures, and in a direct defect, the transversalis fascia is plicated with a continous suture. In both types, a large sheet of polypropylene mesh (about 11 x 11 cm) is used to cover the site of the hernia and the back wall of the inguinal canal. The mesh is either stapled or sutured in place, and then the overlying previously created peritoneal defect must be closed meticulously to avoid internal herniation, a complication which has probably relegated this repair to ‘second-best’ when compared to the totally extraperitoneal (TEP) technique. In the TEP approach, both insufflation, repair and mesh placement are performed in the preperitoneal plane, with or without the aid of a balloon dissection device (Figure 4). Whilst TEP repairs are technically much more challenging than TAPPs (especially when dealing with large indirect hernias) major complications are less frequent and small bowel obstruction most unlikely as the peritoneal cavity is not violated. Despite this hurdle, recent data suggest that TEP repairs are now more commonly performed than TAPP repairs.
a
b
c
The size of the direct hernia a is appreciated when the patient coughs b. The defect in the transversalis fascia has been plugged c.
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Femoral hernias and their repair Femoral hernias account for less than 10% of groin hernias, but may account for up to a third of strangulated hernias. Anatomical considerations and diagnosis: The borders of the femoral canal is about 2 cm in length and runs from the femoral ring to femoral orifice, and can be easily identified. As the peritoneal sac of a femoral hernia enlarges and pushes its way through the normally closed distal end of the canal, it becomes trapped. The canal is bound anteriorly by the inguinal liagament, with its lacunar extension forming the medial wall, and posteriorly is the pectineus muscle/fascia and superior ramus of the pubis. The lateral border of the canal is formed by the femoral vein itself. Rarely, instead of passing down the femoral canal, the hernia lies more laterally, either superficial (so-called prevascular) or deep to the vessels entering the leg. On clinical examination, a femoral hernia is below and lateral to the pubic tubercle and only rarely is there a cough impulse. In the elective situation, the differential diagnosis of femoral herniation includes a lymph node and saphena varix, but it must be emphasized that femoral hernias should be considered when one ponders the cause of a patient’s intestinal (small bowel) obstruction. There are several ways in which a femoral hernia can be repaired and each approach has its merits.
3 The bilayer Prolene Hernia System® (PHS).
The plane of dissection for TEP repairs Subcutaneous tissue
Rectus abdominis muscle
Peritoneal cavity
Peritoneum
How a TAPP approach converts an extraperitoneal operation into an intraperitoneal operation a TEP
Pubic symphysis
TAPP
Peritoneal cavity Umbilicus b
Peritoneum
Femoral hernia: the opened sac a and the defect defined b. 4 SURGERY
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Low approach: the hernial sac is exposed via a low 5 cm groin incision, cleared of the overlying preperitoneal fat, and opened (Figure 5a). The sac is opened to inspect the contents and, in the emergency situation, to check for blood-stained fluid which may indicate bowel ischaemia. The sac is then excised and transfixed and the edges of the defect further clarified (Figure 5b). Traditionally, the defect was closed by loosely approximating the undersurface of the inguinal ligament to Cooper’s ligament with a non-absorbable stitch in an ‘X’ or ‘N’ fashion to form a lattice. This repair can be further reinforced by mobilizing a strip of pectineus fascia, folding it upwards on itself, and stitching it to the inguinal ligament. Care must be taken to protect the femoral vein. Femoral hernias can also be plugged with mesh either as a solid plug or with a preformed mesh plug. These plugs are secured to the adjacent tissues with four or five interrupted nonabsorbable sutures. This approach is safe and quite satisfactory for the vast majority of femoral hernias, but if ischaemic bowel is encountered (e.g. Richter’s hernia) the exposure obtained makes the situation difficult to deal with.
was performed for strangulation. The diagnosis is rarely in doubt as the hernia is tender and there are local signs (e.g. inflammation) and there may be systemic upset (e.g. tachycardia). In an incarcerated inguinal hernia, gentle taxis may allow the hernia to be reduced. This should not be attempted in a femoral hernia as it may cause further damage to the bowel. There may be symptoms and signs of intestinal obstruction and careful attention needs to be paid to the resuscitation of the patient with intravenous fluids and antibiotics. Not all inguinal hernias are at equal risk of strangulation and, whilst irreducible hernias are at higher risk, only 10% of patients operated on for strangulation give a history of preceding herniation. In general, indirect hernias are 10 times more likely to strangulate than direct hernias. Overall, the annual probability of strangulation appears to be between 0.3% and 3%. Recurrent inguinal hernias are probably also at increased risk of strangulation, but the magnitude of the problem is much more difficult to quantify. The anatomy of the femoral canal, with its narrow neck and unyielding boundaries, accounts for the fact that the proportion of femoral hernias presenting with strangulation may be as high as 50%, although recent audits have reported much lower figures. The need for resection for irreversible bowel ischaemia is twice as high in strangulated femoral hernias as in inguinal hernias.
Transinguinal approach: the floor of the inguinal canal (transversalis fascia) can be opened to allow reduction of the sac of the femoral hernia. When the margins are clearly defined, Cooper’s ligament is then directly sutured to the iliopubic tract. Another technique is to obliterate the space with a portion of mesh that can then be continued as an inguinal hernioplasty. This technique has few merits and predisposes the patient to a later direct inguinal hernia.
Complications of groin hernia repair Wound problems: postoperative problems such as bruising and haematoma are not infrequent if repairs are carried out under local anaesthesia, and patients should be warned of this possibility. Careful attention to technique and meticulous haemostasis are important. Wound infection, which predisposes to recurrence, may occur in 1–2% of patients, and although there is no firm evidence for routine antibiotic prophylaxis, we give all adults a single dose of amoxicillin. The inplantation of mesh in hernia repairs leads to an inflammatory process and the development of a seroma which can be detected by ultrasound within a few days of the operation. This is usually a self-limiting process, but large seromas may need to be aspirated. When repeated aspirations are necessary, it is important to consider the possibility of underlying mesh sepsis, but this is an uncommon problem.
High/preperitoneal approach: bowel resection can be readily performed when the hernial sac is uncovered via the preperitoneal approach. The abdominal incision can be a midline (Henry), pararectus (McEvedy), Pfannenstiel or transverse suprainguinal muscle-splitting (Nyhus), but the sac is exposed only when the peritoneum is reflected from the posterior lower abdominal wall. If there is difficulty in reducing the hernia, the peritoneal cavity can be conveniently entered above the incarcerated hernia. The hernial defect can be repaired either with sutures, or a flat piece of mesh to cover the lower portions of the MPO as in a TEP repair. This approach, whilst giving good access, seems excessive in elective cases and we reserve it for the acute case in which we consider resection highly likely. An incarcerated hernia can be explored under local anaesthetic, and the operation later converted to a preperitoneal approach, with a general anaesthetic, if the operative findings so dictate.
Scrotal problems: penile and scrotal oedema is not uncommon and certainly more frequent after the repair of large or bilateral hernias. Ischaemic orchitis and testicular atrophy is said to occur in 0.5–3% of men, and is possibly due to venous congestion (from surgical trauma) rather than from primary arterial damage. Gentle dissection and cord mobilization can minimize its incidence. In addition, it is important to avoid the temptation to deliver the testicle into the wound when operating on an inguinoscrotal hernia. The formation of a hydrocele can also occur when the distal sac of a large hernia is left in situ. The accumulation of this fluid can be prevented by dividing the sac anteriorly along its length.
Laparoscopic approach: the repair of femoral hernias, both elective and acute, has been performed laparoscopically. The operation is similar to that for inguinal hernia repair in that either a TAPP or TEP approach is feasible. The TEP technique is preferred, but it is hard to justify the risk and expense when far less complex alternatives are readily available and can be performed under locoregional anaesthesia. The incarcerated/strangulated groin hernia The incidence of strangulation is an important issue given the accompanying postoperative mortality, especially in the elderly. The Confidential Enquiry into Perioperative Deaths (CEPOD) suggested an overall mortality of about 7% when emergency surgery
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Specific problems: there is a great deal of overlap in the cutaneous areas supplied by the iliohypogastric (L1) and ilioinguinal (L1) nerves and the sensory branches of the genitofemoral nerve (L2). Although patients may have a variable area of skin anaes-
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thesia after operation, it generally returns to normal within a few months and is of little functional consequence. This is in contrast to persistent postoperative pain that is an increasingly recognized problem. Causes include adductor strain, osteitis pubis and neuralgia, with or without neuroma formation. Such patients are best managed with a multidisciplinary approach including specialist pain teams. The femoral artery may be more superficial than imagined, and be at increased risk in thin patients. In femoral hernia repair, the vein may be damaged, but problems such as oedema and deep vein thrombosis may not be apparent for some time after operation, especially if a sutured repair was overly tight.
Guidelines for the urgency of groin hernia repair • Indirect and symptomatic direct inguinal hernias should be repaired to relieve symptoms and eliminate the small risk of strangulation • Small, easily reducible, direct inguinal hernias can be safely left alone as the risk of strangulation is very small • Irreducible hernias and those with a short history should be repaired sooner rather than later • All femoral hernias should be repaired urgently 6
Complications of laparoscopic hernioplasty: all the complications seen after open groin hernia repair are also seen after laparoscopic hernioplasty, but some are unique and specific to this approach. Apart from the complications from general anaesthesia, vascular, bowel and bladder injury may occur during the creation of the pneumoperitoneum, as required in TAPPs. Small bowel obstruction, due to entrapment in peritoneal defects (after TAPP) and trocar site herniation is seen in 1–2% of repairs. Whilst neural injuries can be seen after open repair, damage to the lateral femoral cutaneous nerve (L2, L3) is unique to laparoscopic repairs. Wound seromas can occur in up to 7% of preperitoneal (TEP) repairs, but most resolve within 6–8 weeks of surgery.
Glossary Inguinal canal Passes obliquely through the anterior abdominal wall from the deep to the superficial ring. The posterior wall of the canal is the transversalis fascia. In the male it contains the structures which make up the spermatic cord: 3 arteries (testicular, cremasteric and to the vas), 3 nerves (ilioinguinal, genital branch of genitofemoral and sympathetics) and 3 other structures (vas deferens, pampiniform plexus of veins and remnants of the processus vaginalis).
Results of inguinal hernia repair in the modern era When considering recurrence, it is important that there is a long period of follow-up as 50% of recurrences do not appear for five or more years after the initial operation, and 20% may not be apparent for 15–25 years! Recurrence occurring in the first few years is probably due to technical failure (technique, tension, missed hernia, infection). Thereafter, tissue weakness/failure, and a later, acquired hernia are more likely causes for the ‘recurrence’. Thus, a follow-up of ten years would seem the minimum required in order to quote a repair’s ‘true’ recurrence rate. From the literature, it appears that ‘general’ surgeons may have recurrence rates of 5–10%, whilst more dedicated surgeons have rates of between 1 and 2%, and published hernia ‘zealots’ rates of <1%. Indeed, all the repairs described above have published series with recurrence rates of <1%. The real challenge now is for the general surgeon to attain rates of less than 1–2% and, with this in mind, the surgeon must choose the repair he/she is most comfortable with. Thus, when comparing recurrence rates, it is prudent to recall the thoughts of Kirk who, in 1983, wrote: ‘In my experience, outstanding and thoughtful surgeons who devise new techniques attribute their success to the method. They are too modest. Their colleagues know that it is not the particular method that brings success, but the enthusiasm for perfection and painstaking skill with which it is accomplished.’
Indirect inguinal hernia Passes through the deep inguinal ring and extends down the canal towards the scrotum. The sac is lateral to the inferior epigastric vessels. If it passes into the scrotum, it is described as inguinoscrotal. Indirect hernias are twice as common as ‘direct’ ones. Sliding hernia Occurs when a viscus (often sigmoid colon or caecum), or its mesentery forms one of the walls of the hernial sac. Occurs in about 5% of hernias and more common in the elderly. It is very rare for there to be a sliding component in direct or femoral hernias. Direct inguinal hernia Is one that is due to a weakened transversalis fascia in Hesselbach’s triangle. It is most unusual for the sac to pass into the scrotum. They are common in the obese and elderly and are often bilateral, but rarely incarcerate as the neck is wide. Femoral hernia Is one that comes through the femoral canal medial to the femoral vein. As its neck is narrow it is more likely to strangulate than an inguinal hernia. Incarcerated hernia If the contents of a hernial sac become entrapped, the hernia is said to be irreducible or incarcerated.
Open tension-free or laparoscopic groin hernia repair? Laparoscopic cholecystectomy has many advantages for the patient, hospital and employer when compared to the open procedure. However, is this true when comparing laparoscopic and open tension-free inguinal hernioplasty? Laparoscopic surgeons claim there is less postoperative pain and earlier return to full activity, but the overall picture is not that simple, as we know these end-points are quite subjective, irrespective of whether
Strangulated hernia If the blood flow to the viscus in an incarcerated hernia becomes compromised, the hernia is described as strangulated, and if not reduced/repaired, necrosis and perforation will follow. 7
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the patient is motivated or not. Furthermore, laparoscopic repair is certainly not suitable for all patients with a symptomatic hernia. In a recent MRC randomized trial, over 40% of identified patients were excluded because they were unfit, had large or difficult hernias, or had had previous abdominal surgery. In addition, laparoscopy incurs extra costs (theatre time, laparoscopic equipment), and it has been estimated that a laparoscopic repair has an additional UK NHS cost of about £300 per procedure. Furthermore, given the higher intraoperative risks (after TAPP), and probable higher rates of recurrence with longer follow-up, there seems little to recommend its widespread use. In addition, many experienced surgeons find the repair awkward and timeconsuming. If the difference in outcome was real, the last decade would have seen the numbers of laparoscopic repairs rising but, to date, less than 5–10% of repairs in the UK are performed in this manner. The UK NHS National Institute for Clinical Excellence (NICE) has recently appraised the role of laparoscopic surgery in inguinal hernia repair and has suggested the following tailored approach: • primary inguinal hernias should be repaired with an open mesh technique. • recurrent and bilateral hernias may be repaired laparoscopically (TEP approach) in units with appropriately trained teams who regularly undertake these procedures. Guidelines for the urgency of groin hernia repair and a glossary of terms are described in Figures 6 and 7 respectively. u
Inflammatory Bowel Disease Charles Maxwell-Armstrong Richard Cohen
The term ‘inflammatory bowel disease’ (IBD) includes ulcerative colitis (UC) and Crohn’s disease (CD), as well as cases of indeterminate colitis, where the patient may show features of both. UC is an inflammatory disorder affecting the colon, typically extending proximally from the rectum. The terminal ileum is not involved, except in cases of total colitis, where there may be a ‘backwash’ ileitis, where the ileum becomes inflamed due to an incompetent ileocaecal valve. CD affects any part of the bowel from mouth to anus, occasionally involving discontinuous discrete areas: ‘skip lesions’.
Epidemiology In the UK, the prevalence of IBD is 5.12/1000 at age 43 years, and 2.02–2.54/1000 by age 33 years. The figures for the incidence of UC vary between 2.6 and 15.1 cases per 100,000 people per annum, with corresponding figures of 0.7 to 6.6 for CD. Recent studies in children have found the incidence of IBD to be 5.2/ 100,000 children per year, substantially greater than the figure of 2.2 reported in the mid-1980s. It is important that figures suggesting an increase in IBD are interpreted with caution as there may be variations in data collection, reporting, and confusion with cases that were probably infective.
FURTHER READING Bay-Nielsen M, Kehlet H, Strand L et al. Quality assessment of 26,304 herniorrhaphies in Denmark: a prospective nationwide study. Lancet 2001; 358(9288): 1124–8. Guidance on the Use of Laparoscopic Surgery for Inguinal Hernia. London: NHS National Institute for Clinical Excellence (NICE), 2001. The MRC Laparoscopic Groin Hernia Trial Group. Laparoscopic versus open repair of groin hernia: a randomised comparison. Lancet 1999; 354 (9174): 185–90. Vrijland W W, van den Tol M P, Luijendijk R W et al. Randomized clinical trial of non-mesh versus mesh repair of primary inguinal hernia. Br J Surg 2002; 89(3): 293–7.
Pathology The macroscopic appearance of UC varies according to disease severity, ranging from mild serosal injection, to more severe inflammatory change (Figure 1), with colonic distension, and wall thinning (in cases of toxic megacolon). Healed, chronic colitis may also have a characteristic ‘scarred’ picture at colonoscopy (Figure 2). Microscopically, there is initially an acute inflammatory response, characterized by neutrophil, plasma cell and eosinophil infiltration. This is not transmural, and involves the lamina propria. More chronic changes include the formation of crypt abscesses, and disturbances in crypt architecture. CD macroscopically may be characterized by a number of features including, fistulas (Figure 3), from bowel to any or all of skin, bladder, vagina, and other areas of intestine. The bowel may be thickened, and strictured, with characteristic ‘fat wrapping’. Unlike UC, CD shows a transmucosal infiltrate and granulomas, usually containing giant cells.
Charles Maxwell-Armstrong is a Consultant Surgeon at University Hospital, Nottingham, UK. Richard Cohen is a Consultant Colorectal Surgeon at St Mark’s Hospital and Central Middlesex Hospital, London, UK.
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