Hernia - PDF

Hernia By Dr. Haitham Nabeel Your Date Here Your Footer Here  Introduction Your Date Here Your Footer Here Hernia A hernia is the bulging of part of the contents of the abdominal cavity through a weakness in the abdominal wall....

Hernia By Dr. Haitham Nabeel Your Date Here Your Footer Here  Introduction Your Date Here Your Footer Here Hernia A hernia is the bulging of part of the contents of the abdominal cavity through a weakness in the abdominal wall. Your Date Here Your Footer Here 3 Anatomical causes of abdominal wall herniation Despite the complex design of the abdominal wall, the only natural weaknesses caused by inadequate muscular strength are the lumbar triangles and the posterior wall of the inguinal canal. Many structures pass into and out of the abdominal cavity creating weakness which can lead to hernia formation. The most common example is the inguinal canal in males, along which the testis descends from abdomen to scrotum at the time of birth. The testicular artery, veins and vas pass though this canal (the round ligament in females). The resultant weakness leads to an indirect or lateral-type inguinal hernia. The evolutionary advantage of testicular descent must outweigh the disadvantage of a high risk of herniation. Other examples are: oesophagus → hiatus hernia, femoral vessels → femoral hernia, obturator nerve → obturator hernia, sciatic nerve → sciatic hernia. Your Date Here Your Footer Here 4 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 5 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 6  In adult surgery, 80% of all hernia repairs are for inguinal hernia. Clinical pearl! Your Date Here Your Footer Here 7 Anatomical causes of abdominal wall herniation An inguinal hernia (indirect) also occurs through the developmental failure of the processus vaginalis to close. As the testis descends, it pulls a tube of peritoneum along with it. This tube should naturally fibrose and become obliterated but often it fails to fibrose and allows a hernia to form. Recent studies have shown that calcitonin gene-related peptide and hepatocyte growth factor influence the closure of the processus, raising the possibility of a hormonal cause of hernia development. Failure of normal development may lead to weakness of the abdominal wall. Examples are diaphragmatic, umbilical and epigastric hernias. Muscles which should unite during development fail to form strong unions with hernia development at birth or in later life. Herniation at the umbilicus has both components, i.e. weakness due to structures passing through the abdominal wall in fetal life and developmental failure of closure. The risk of inguinal hernia is related to the anatomical shape of the pelvis and is higher in patients having a wider and shorter pelvis. Your Date Here Your Footer Here 8 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 9 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 10 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 11 Anatomical causes of abdominal wall herniation Weakness of abdominal muscles may be the result of sharp trauma. Most commonly, this results from abdominal surgery but also occurs after stabbing. A surgical scar, even with perfect wound healing, has only 70% of the initial muscle strength. This loss of strength can result in herniation in at least 10% of surgical incisions. Smaller laparoscopic port-site incisions have a hernia rate of 1%. Increasing use of this surgical approach should lead to a fall in the incidence of incisional hernia. Muscle damage by blunt trauma or tearing of the abdominal muscles requires exceptional force and is rare. The sudden presence of a mass in the rectus muscle may be a rectus sheath haematoma, occasionally due to trauma but nowadays more often due to excessive anticoagulation therapy. Primary muscle pathology and neurological conditions can lead to muscle weakness and occasionally present to the surgeon as a ‘hernia’. Your Date Here Your Footer Here 12 Incisional hernia A bulging mass is visible in the epigastric region, with an overlying midline laparotomy scar. These features suggest an incisional hernia. Your Date Here Your Footer Here 13 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 14 Pathophysiology of hernia formation A normal abdominal wall has sufficient strength to resist high abdominal pressure and prevent herniation of content. Herniation has been attributed to high pressures from constipation, prostatic symptoms, excessive coughing in respiratory disease and obesity. However, it has been shown that hernia is no more common in Olympic weight lifters than the general population, suggesting that high pressure is not a major factor in causing a hernia. Many patients will first notice a hernia after excessive straining. Your Date Here Your Footer Here 15 Pathophysiology of hernia formation There is good evidence that hernia is a ‘collagen disease’ and due to an inherited imbalance in the types of collagen. This is supported by histological evidence and relationships between hernia and other diseases related to collagen, such as aortic aneurysm. Hernia development is more common in pregnancy due to hormonally induced laxity of pelvic ligaments. It is also more common in elderly people due to degenerative weakness of muscles and fibrous tissue. A recent Swedish report has shown that inguinal hernia is less common in obese patients, with hernia risk being negatively related to body mass index (BMI), contrary to widespread belief. Hernia is more common in smokers. Your Date Here Your Footer Here 16 Common principles in abdominal hernia An abdominal wall hernia has two essential components, a defect in the wall and content, i.e. tissue that has been forced outwards through the defect. The weakness may be entirely in muscle, such as an incisional hernia. It may also be in fascia, similar to an epigastric hernia through the linea alba. It may have a bony component, such as a femoral hernia. The weakness in the wall is usually the narrowest part of the hernia which expands into the subcutaneous fat outside the muscle. The defect varies in size and may be very small or indeed very large. The nature of the defect is important to understanding the risk of hernia complications. A small defect with rigid walls traps the content and prevents it from freely moving in and out of the defect, increasing the risk of complications. Your Date Here Your Footer Here 17 Common principles in abdominal hernia Your Date Here Your Footer Here 18 Common principles in abdominal hernia The content of the hernia may be tissue from the extraperitoneal space alone, such as fat within an epigastric hernia or urinary bladder in a direct inguinal hernia. However, if such a hernia enlarges then peritoneum may also be pulled into the hernia secondarily along with intraperitoneal structures such as bowel or omentum; a good example is a ‘sliding type’ of inguinal hernia. More commonly, when peritoneum is lying immediately deep to the abdominal wall weakness, pressure forces the peritoneum through the defect and into the subcutaneous tissues. This ‘sac’ of peritoneum allows bowel and omentum to pass through the defect. In most cases, the intraperitoneal organs can move freely in and out of the hernia, a ‘reducible’ hernia, but if adhesions form or the defect is small, bowel can become trapped and unable to return to the main peritoneal cavity, an ‘irreducible’ hernia, with high risk of further complications. The narrowest part of the sac, at the abdominal wall defect, is called the ‘neck of the sac’. Your Date Here Your Footer Here 19 Common principles in abdominal hernia When tissue is trapped inside a hernia it is in a confined space. The narrow neck acts as a constriction ring impeding venous return and increasing pressure within the hernia. Resulting tension leads to pain and tenderness. If the hernia contains bowel then it may become ‘obstructed’, partially or totally. If the pressure rises sufficiently, arterial blood is not able to enter the hernia and the contents become ischaemic and may infarct. The hernia is then said to have ‘strangulated’. The wall of the bowel perforates, releasing infected, toxic bowel content into the tissues and ultimately back into the peritoneal cavity. The risk of strangulation is highest in hernias that have a small neck of rigid tissue, leading first to irreducibility and on to strangulation. The term ‘incarcerated’ is not clearly defined and used to imply a hernia that is irreducible and developing towards strangulation. Your Date Here Your Footer Here 20 Common principles in abdominal hernia Your Date Here Your Footer Here 21 Common principles in abdominal hernia Your Date Here Your Footer Here 22 Common principles in abdominal hernia In a special circumstance (Richter’s hernia) only part of the bowel wall enters the hernia. It may be small and difficult or even impossible to detect clinically. Bowel obstruction may not be present but the bowel wall may still become necrotic and perforate with life-threatening consequences. Femoral hernia may present in this way often with diagnostic delay and high risk to the patient. An interstitial hernia occurs when the hernia extends between the layers of muscle and not directly through them. This is typical of a spigelian hernia An internal hernia is a term used when adhesions form within the peritoneal cavity. leading to abnormal pockets into which bowel can enter and become trapped. As there is no defect within the abdominal wall, the term ‘hernia’ is confusing. Your Date Here Your Footer Here 23 Femoral hernia Diagrammatic representation of gangrenous Richter’s hernia from a case of strangulated femoral hernia. Your Date Here Your Footer Here 24 Spigelian hernia Herniation of intraabdominal contents through the semilunar line; commonly adjacent to the arcuate line (typically below the umbilicus) The semilunar line is the lateral border of the rectus abdominis. The arcuate line is the inferior border of the posterior rectus sheath. The lack of posterior rectus sheath below the arcuate line is assumed to predispose this region to hernia formation. Your Date Here Your Footer Here 25 Clinical history and diagnosis in hernia cases Patients are usually aware of a lump on the abdominal wall under the skin. Self- diagnosis is common. The hernia is usually painless but patients may complain of an aching or heavy feeling. Sharp, intermittent pains suggest pinching of tissue. Severe pain should alert the surgeon to a high risk of strangulation. One should determine whether the hernia reduces spontaneously or needs to be helped. The patient should be asked about symptoms that might suggest bowel obstruction. It is important to know if this is a primary hernia or whether it is a recurrence after previous surgery. Recurrent hernia is more difficult to treat and may require a different surgical approach. Your Date Here Your Footer Here 26 Inguinal hernia Your Date Here Your Footer Here 27 Clinical history and diagnosis in hernia cases General questions about the cardiac and respiratory systems are necessary to assess a patient’s anaesthetic risk. In a man with a groin hernia, history of prostatic symptoms indicates a high risk of postoperative urinary retention. Intake of anticoagulants such as warfarin is important because this impacts on future surgery. Many hernia operations can be performed as a day case or single overnight stay, so that suitability for such treatment needs to be assessed, including home support, distance from the hospital, mobility levels, etc. Your Date Here Your Footer Here 28 Examination for hernia The patient should be examined lying down initially and then standing as this will usually increase hernia size. In some cases no hernia will be apparent with the patient lying. The patient is asked to cough, when an occult hernia may appear. Divarification is best seen by asking a supine patient to simply lift his head off the pillow. The overlying skin is usually of normal colour. If bruising is present this may suggest venous engorgement of the content. If there is overlying cellulitis then hernia content is strangulating and the case should be treated as an emergency. In most cases a cough impulse is felt. Gentle pressure is applied to the lump and the patient is asked to cough. If an impulse is felt this is due to increased abdominal pressure being transmitted into the hernia. In cases where the neck is tight and the hernia irreducible there may be no cough impulse. This can lead to failure of diagnosis and is typical of femoral hernia where lack of an impulse leads the clinician to misdiagnose a lymph node Your Date Here Your Footer Here 29 Strangulated inguinal hernia An ill-defined swelling with erythema of the overlying skin can be seen in the right inguinal region. This is the typical appearance of a strangulated inguinal hernia, which should be differentiated from other causes of erythematous inguinal swellings (e.g., inguinal lymphadenitis, abscess, hematoma) with imaging. Your Date Here Your Footer Here 30 Examination for hernia Cough impulse can also occur in a saphena varix, which may be referred to a surgeon as a suspected inguinal hernia. It is not unusual for a patient to describe an intermittent swelling but the surgeon finds nothing on examination. This is due to muscle tightening in an anxious patient. If, on lying, the hernia does not reduce spontaneously, the surgeon asks the patient to attempt reduction because he may be well practised in this task although the surgeon might cause unnecessary discomfort. If neither the patient nor the surgeon can reduce the hernia then treatment is more urgent. An irreducible hernia may influence the decision between open and laparoscopic surgery. With the hernia reduced, the surgeon assesses the size, rigidity and number of defects. Multiple defects may be present in incisional hernia. Your Date Here Your Footer Here 31 Examination for hernia Your Date Here Your Footer Here 32 Investigations for hernia For most hernias, no specific investigation is required, the diagnosis being made on clinical examination. However, the patient may have symptoms suggesting a hernia, but no hernia is found, or have a swelling suggestive of hernia but with clinical uncertainty. It is important to be certain that any symptoms described are due to a hernia and not to coexisting pathology. There may also be a requirement for more detailed information than can be found by examination alone. A plain radiograph of the abdomen is of little value although a hiatus hernia and diaphragmatic hernia may be seen on a chest radiograph. An ultrasound scan may be helpful in cases of irreducible hernia, where the differential diagnosis includes a mass or fluid collection, or when the nature of the hernia content is in doubt. Your Date Here Your Footer Here 33 Investigations for hernia Ultrasonography is very useful in the early postoperative period when a haematoma or seroma may develop, and be difficult to distinguish from an early recurrence. Ultrasonography is non-invasive and low cost but operator dependent. Computed tomography is helpful in complex incisional hernia, determining the number and size of muscle defects, identifying the content, giving some indication of presence of adhesions and excluding other intra-abdominal pathology such as ascites, occult malignancy and portal hypertension. Contrast barium radiology is occasionally useful in the absence of CT. Contrast may also be injected directly into the peritoneum, a herniagram, to identify an occult sac, especially in occult inguinal hernia. Your Date Here Your Footer Here 34 Investigations for hernia Magnetic resonance imaging (MRI) can help in the diagnosis of sportsman’s groin where pain is the presenting feature and the surgeon needs to distinguish an occult hernia from an orthopaedic injury. Laparoscopy itself may be used. In incisional hernia, initial laparoscopy may determine that a laparoscopic approach is feasible or not depending on the extent of adhesions. In inguinal hernia repair by the transabdominal route, initial laparoscopy can determine the presence of an occult contralateral hernia which has been described in up to 20% of patients. Your Date Here Your Footer Here 35 Investigations for hernia Your Date Here Your Footer Here 36 Management principles An abdominal wall hernia does not necessarily require repair. A patient may request surgery for relief of symptoms of discomfort, for cosmesis or to establish the diagnosis when in doubt. The surgeon should recommend repair when complications are likely, the most worrying being strangulation with bowel obstruction and bowel infarction. All cases of femoral hernia, with high risk of strangulation, should be repaired surgically. Any case of irreducible hernia, especially where there is pain and tenderness, should be offered repair unless coexisting medical factors place the patient at very high risk from surgery or anaesthesia. Increasing difficulty in reduction and increasing size are indications for surgery. Surgery should be offered to younger adult patients as symptoms and complications are likely over time. Your Date Here Your Footer Here 37 Management principles In reality, most patients with a hernia should be offered repair. In elderly people, if the hernia is asymptomatic, small in size, can be reduced easily and is not causing anxiety, then observation alone should be sufficient. This policy, called ‘watchful waiting’, has been studied in asymptomatic inguinal hernia. One study reported such a policy to be safe but a second study was abandoned when a small number of patients developed strangulation. A truss can be used to control a hernia but few surgeons would recommend this approach. Small paraumbilical hernias are often seen. They cause few symptoms and usually contain fat or omentum with a very low risk of complications. Your Date Here Your Footer Here 38 Management principles Large incisional hernias, particularly recurrent, present a major problem. Surgical repair is a complex procedure with significant risk of complications and later recurrence. When the neck is wide, the risk of strangulation is low. In obese and elderly patients, these risks may outweigh the benefits of surgery and it is common for surgeons to adopt a conservative approach. Any patient who presents with acute pain in a hernia, particularly if it is irreducible, should be offered surgery. Often, in a patient with an irreducible hernia, after admission to hospital and adequate analgesia, the hernia will reduce due to muscle relaxation. The likelihood of similar episodes is very high and surgery should be recommended at this admission or soon after. Your Date Here Your Footer Here 39 Management principles Your Date Here Your Footer Here 40 Surgical approaches to hernia All surgical repairs follow the same basic principles: 1 reduction of the hernia content into the abdominal cavity with removal of any non-viable tissue and bowel repair if necessary 2 excision and closure of a peritoneal sac if present or replacing it deep to the muscles 3 reapproximation of the walls of the neck of the hernia if possible 4 permanent reinforcement of the abdominal wall defect with sutures or mesh. Your Date Here Your Footer Here 41  Inguinal hernia Your Date Here Your Footer Here Inguinal hernia The inguinal hernia, often referred to as a ‘rupture’ by patients, is the most common hernia in men and women but much more common in men. There are two basic types that are fundamentally different in anatomy, causation and complications. However, they are anatomically very close to each other, surgical repair techniques are very similar and ultimate reinforcement of the weakened anatomy is identical, so they are often referred to together as inguinal hernia. The congenital inguinal hernia is known as indirect, oblique or lateral whereas the acquired hernia is called direct or medial. There is a third ‘sliding’ hernia that is acquired but is lateral in position Your Date Here Your Footer Here 43 Anatomical causes of abdominal wall herniation Your Date Here Your Footer Here 44 Basic anatomy of the inguinal canal As the testis descends from the abdominal cavity to the scrotum in males it firsts passes through a defect called the deep inguinal ring in the transversalis fascia, just deep to the abdominal muscles. This ring lies midway between the anterior superior iliac spine and the pubic tubercle, approximately 2–3 cm above the femoral artery pulse in the groin. The inferior epigastric vessels lie just medial to the deep inguinal ring, passing from the iliac vessels to rectus abdominis. Muscle fibres of the innermost two layers of the lateral abdominal wall, the transversus muscle and the internal oblique muscle, arch over the deep inguinal ring from lateral to medial before descending to become attached to the pubic tubercle. These two muscles fuse and become tendinous, hence this arch is referred to as the conjoint tendon. Below this arch there is no muscle but only transversalis fascia and external oblique aponeurosis, resulting in weakness Your Date Here Your Footer Here 45 Basic anatomy of the inguinal canal Your Date Here Your Footer Here 46 Inguinal hernia Your Date Here Your Footer Here 47 Basic anatomy of the inguinal canal The testis proceeds medially and downwards along the inguinal canal. Anterior to the canal is the aponeurosis of the external oblique muscle, the fibres of which run downwards and medially. The testis finally emerges through a V-shaped defect in the aponeurosis, the superficial inguinal ring, and descends into the scrotum. The inguinal canal is roofed by the conjoint tendon, its posterior wall is transversalis fascia, an anterior wall is the external oblique aponeurosis and a floor, which is also the external oblique, that rolls inwards at its lower margin and thickens to become the inguinal (Poupart’s) ligament. The inguinal canal in males contains the testicular artery, veins, lymphatics and the vas deferens. In females, the round ligament descends through the canal to end in the vulva. Three important nerves, the ilioinguinal, the iliohypogastric and the genital branch of the genitofemoral nerve, also pass through the canal. Your Date Here Your Footer Here 48 Inguinal hernia Your Date Here Your Footer Here 49 Basic anatomy of the inguinal canal As the testis descends, a tube of peritoneum is pulled with the testis and wraps around it ultimately to form the tunica vaginalis. This peritoneal tube should obliterate, possibly under hormonal control, but it commonly fails to fuse either in part or totally. As a result, bowel within the peritoneal cavity is able to pass inside the tube down towards the scrotum. Inguinal hernia in neonates and young children is always of this congenital type. However, in other patients, the muscles around the deep inguinal ring can prevent a hernia from developing until later in life, when, under the constant positive abdominal pressure, the deep inguinal ring and muscles are stretched and a hernia becomes apparent. As the hernia increases in size, the contents are directed down into the scrotum. These hernias can become massive and may be referred to as a scrotal hernia Your Date Here Your Footer Here 50 Anatomy of the inguinal canal Sagittal plane of the male inguinal area showing the walls of the inguinal canal: Roof (superior): internal oblique (1) and transversus abdominis (2) muscles; Anterior wall: external oblique aponeurosis (3) and internal oblique muscle laterally (not shown) Posterior wall: transversalis fascia (4), conjoint tendon medially (not shown), parietal peritoneum (5), and peritoneal cavity (6); Floor (inferior): inguinal ligament (7), lacunar ligament (8), and superior pubic ramus (9). Your Date Here Your Footer Here 51 Basic anatomy of the inguinal canal An indirect hernia is lateral because its origin is lateral to the inferior epigastric vessels. It is also oblique as the hernia passes obliquely from lateral to medial through the abdominal muscle layers. The second type of inguinal hernia, referred to as direct or medial, is acquired. It is a result of stretching and weakening of the abdominal wall just medial to the inferior epigastric (IE) vessels. Looked at from within the abdominal cavity, there is a triangle referred to as Hasselbach’s triangle, the three sides of which are the IE vessels laterally, the lateral edge of rectus abdominis medially and the pubic bone below (the iliopubic tract) This area is weak because the abdominal wall here consists of only transversalis fascia covered by the external oblique aponeurosis. A direct, medial hernia is more likely in elderly patients. It is broadly based and therefore unlikely to strangulate. The medially placed bladder can be pulled into a direct hernia Your Date Here Your Footer Here 52 Inguinal hernia Your Date Here Your Footer Here 53 Inguinal hernia Laparoscopic view of the posterior inguinal region with hernia defects highlighted: yellow, medial inguinal; blue, lateral inguinal; green, femoral. Your Date Here Your Footer Here 54  "The DIRECT path leads through the MiDdle, the INDIRECT path goes beLow." (DIRECT hernias lie MeDial and INDIRECT hernias lie Lateral to the inferior epigastric vessels) Clinical pearl! Your Date Here Your Footer Here 55 Basic anatomy of the inguinal canal The third type of inguinal hernia is referred to as a sliding hernia. This is also an acquired hernia due to weakening of the abdominal wall, but occurs at the deep inguinal ring lateral to the IE vessels. Retroperitoneal fatty tissue is pushed downwards along the inguinal canal. As more tissue enters the hernia, peritoneum is pulled with it, thus creating a sac. However, the sac has formed secondarily, distinguishing it from a classic indirect hernia. On the left side, sigmoid colon may be pulled into a sliding hernia and on the right side the caecum. Surgeons need extra caution during repair because the wall of the large bowel may not be covered by peritoneum and can be damaged. Occasionally, both lateral and medial hernias are present in the same patient (pantaloon hernia). Your Date Here Your Footer Here 56 Basic anatomy of the inguinal canal Your Date Here Your Footer Here 57 Classification Many surgeons over the past 100 years have attempted to classify inguinal (and femoral) hernias, including Casten, Halverson and McVay, Zollinger, Ponka, Gilbert and Nyhus. The European Hernia Society has recently suggested a simplified system of: primary or recurrent (P or R); lateral, medial or femoral (L, M or F); defect size in fingerbreadths assumed to be 1.5 cm. A primary, indirect, inguinal hernia with a 3-cm defect size would be PL2. Your Date Here Your Footer Here 58 Diagnosis of an inguinal hernia In most cases, the diagnosis of an inguinal hernia is simple and patients often know their diagnosis because they are so common. Usually these hernias are reducible presenting as intermittent swellings, lying above and lateral to the pubic tubercle, with an associated cough impulse. Often the hernia will reduce on lying and reappear on standing. With the patient lying down, the patient is asked to reduce the hernia if it has not spontaneously reduced. If the patient cannot then the surgeon gently attempts to reduce the hernia. Once reduced, the surgeon identifies the bony landmarks of the anterosuperior iliac spine and pubic tubercle to landmark the deep inguinal ring at the mid-inguinal point. Gentle pressure is applied at this point and the patient asked to cough. If the hernia is controlled with pressure on the deep inguinal ring then it is likely to be indirect/lateral and if the hernia appears medial to this point then it is direct/medial. Other examination techniques have been suggested but even experienced surgeons find it difficult to distinguish lateral and medial hernias with certainty Your Date Here Your Footer Here 59 Inguinal hernia Your Date Here Your Footer Here 60 Palpation of the inguinal canal in a male patient 1. Ask the patient to stand up. 2. Palpate from the scrotal skin towards the superficial external inguinal ring. 3. Ask the patient to cough or strain and bear down. The increase in intraabdominal pressure leads to bulging of an existing inguinal hernia, which can then be felt with the tip of the finger. An indirect inguinal hernia can be palpated from the lateral direction, while a direct inguinal hernia can be palpated cranially. Your Date Here Your Footer Here 61 Inguinal hernia A huge scrotal hernia that has descended into the scrotum. The overlying skin has become gangrenous and sloughed away Your Date Here Your Footer Here 62 Diagnostic difficulties Confirmation of the diagnosis may not be possible when the patient describes an intermittent swelling but nothing is found on examination. Surgeons will often accept the diagnosis on history alone but re-examination at a later date or investigation by ultrasound scan may be requested. If an inguinal hernia becomes irreducible and tense there may be no cough impulse. Differential diagnosis would include a lymph node, groin mass or an abdominal mass. Such cases require urgent investigation by either ultrasonography or CT. Large scrotal hernias may be misdiagnosed as a hydrocele or other testicular swelling. The surgeon should be able to identify the upper limit of a scrotal swelling but a large scrotal hernia has no upper limit because it extends back along the inguinal canal to the peritoneal cavity. Your Date Here Your Footer Here 63  In cases of doubt, ultrasonography should establish the diagnosis. Clinical pearl! Your Date Here Your Footer Here 64 Malignant mass of nodes Your Date Here Your Footer Here 65 Diagnostic difficulties As inguinal hernia is so common, less-experienced clinicians might suggest this diagnosis when referring cases of femoral hernia or spigelian hernia. Also patients with a saphena varix may present with a swelling that increases in size on standing and with a definite cough impulse and be misdiagnosed as a hernia. The same can be true for a varicocele. It is essential to examine the scrotal contents to exclude other pathologies and to check that the patient has two testes. It is important to examine the opposite side because contralateral hernia is common. Even if the contralateral side is weak, then bilateral repair should be recommended because the risk of contralateral recurrence is high. Of all patients 10% will present with bilateral inguinal hernias and up to 20% more will have an occult contralateral hernia on laparoscopic evaluation. A patient with a single hernia has a lifetime 33% risk of developing a hernia on the other side. Some surgeons have suggested that all patients should be offered bilateral repair, especially if laparoscopic surgery is planned, but this is not widespread practice at present. Your Date Here Your Footer Here 66  To avoid missing inguinal hernias, routinely examine the inguinal canal in patients with unexplained acute abdominal pain and/or clinical features of bowel obstruction, especially in those with verbal impairment. Clinical pearl! Your Date Here Your Footer Here 67 Investigations for inguinal hernia Most cases require no diagnostic tests but ultrasonography, CT and MRI are occasionally used. A herniogram involves the injection of contrast into the peritoneal cavity followed by screening which shows the presence of a sac or asymmetrical bulging of the inguinal anatomy. Your Date Here Your Footer Here 68 Cystogram This cystogram shows the urinary bladder, part of which has descended into a left direct inguinal hernia Your Date Here Your Footer Here 69 Management of inguinal hernia It is safe to recommend no active treatment in cases of asymptomatic, direct hernia, particularly in elderly patients who do not wish for surgical intervention. These patients should be warned to seek early advice if the hernia increases in size or becomes symptomatic. Surgical trusses are not recommended but may be required for occasional patients who refuse any form of surgical intervention. Elective surgery for inguinal hernia is a common and simple operation. It can be undertaken under local, regional or general anaesthesia with minimal risk, even in high-risk patients. Herniotomy In children who have lateral hernias with a persistent processus, it is sufficient just to remove and close the sac. This is called a herniotomy. In adult surgery, herniotomy alone has a high recurrence rate and some form of muscle strengthening is added (herniorrhaphy). Your Date Here Your Footer Here 70 Management of inguinal hernia Your Date Here Your Footer Here 71 Management of inguinal hernia Your Date Here Your Footer Here 72 Shouldice repair Illustration of the inguinal area in a male patient (sagittal view, medial to the epigastric blood vessels) The Shouldice technique is a procedure for a tension-free open inguinal hernia repair without placement of a synthetic mesh. After resecting or repositioning the hernial sac in the peritoneal cavity, the surgeon closes the parietal peritoneum. The incised transversalis fascia is positioned so that the upper and lower flap overlap each other, and the flaps are sutured together cranially and anchored to the inguinal ligament caudally. For ventral stabilization, both the abdominal internal oblique muscle and transverse muscle are sutured to the inguinal ligament. Closure of the aponeurosis of the external abdominal oblique muscle positions the spermatic cord between this aponeurosis and abdominal internal oblique muscle. Your Date Here Your Footer Here 73 Lichtenstein repair Illustration depicting the inguinal area in a male patient (sagittal view, medial to the epigastric blood vessels) The Lichtenstein technique is a procedure for tension-free open inguinal hernia repair by implanting a synthetic mesh. After resecting or repositioning the hernial sac, the surgeon closes the parietal peritoneum. A synthetic mesh (gray) is then placed in between the abdominal internal oblique muscle and the external oblique aponeurosis and sutured to both. Closure of the aponeurosis of the external abdominal oblique muscle positions the spermatic cord between this aponeurosis and the mesh. Your Date Here Your Footer Here 74 Transabdominal preperitoneal repair (TAPP) Schematic representation of male inguinal area in sagittal plane, medial to the epigastric blood vessels The TAPP technique allows for the laparoscopic repair of inguinal hernia. The hernial sac is repositioned into the peritoneal cavity. Next, the parietal peritoneum is opened from the abdominal cavity (white arrow). The surgeon then places a synthetic mesh (gray) between the parietal peritoneum and the transverse fascia and closes the parietal peritoneum again, e.g., using suture. The intra-abdominal pressure and the counter-pressure of the abdominal muscles stabilize the mesh, which may also be anchored using absorbable clips or fibrin glue. Your Date Here Your Footer Here 75 Total extraperitoneal repair (TEP) Schematic representation of a male inguinal area in sagittal plane, medial to epigastric blood vessels The TEP technique allows for laparoscopic, extraperitoneal repair of inguinal hernia using a synthetic mesh. Following the repositioning of the hernial sac in the peritoneal cavity, the mesh (gray) is placed between the parietal peritoneum and the transverse fascia. Access is minimally invasive and remains preperitoneal, between the parietal peritoneum and transverse fascia (light arrow). The intra-abdominal pressure and the counter-pressure of the abdominal muscles stabilize the mesh, which may also be anchored using absorbable clips or fibrin glue. Your Date Here Your Footer Here 76 Emergency inguinal hernia surgery Of inguinal hernia patients 95% present at clinics and only 5% as an emergency with a painful irreducible hernia that may progress to strangulation and possible bowel infarction. The morbidity and mortality of emergency inguinal hernia surgery are high and surgery needs to be performed rapidly in a well-resuscitated patient with adequate postoperative high dependency or intensive care if necessary. The principles of surgery are the same as in an elective setting. Open surgery is preferred when a hernia is irreducible or if there is any risk of bowel resection. Infection may complicate these cases but most surgeons would still use a lightweight, synthetic mesh repair covered by appropriate antibiotics. Your Date Here Your Footer Here 77  Manual reduction of an inguinal hernia should not be attempted if there are any signs of strangulation! Clinical pearl! Your Date Here Your Footer Here 78 Complications of inguinal hernia surgery Despite this being a common procedure and technically straightforward, postoperative complications are common. Immediate complications include bleeding (which may be due to accidental damage to the inferior epigastric or iliac vessels) and urinary retention that may require catheterisation. Occasional over-enthusiastic infusion of local anaesthetic may lead to femoral nerve blockade, the patient being unable to move a leg. This usually resolves over 12 hours but is alarming. Over the next week, seroma formation and wound infection may occur. Seroma is due to an excessive inflammatory response to sutures or mesh and cannot be prevented. In most cases the fluid resolves spontaneously but may require aspiration. After laparoscopic surgery, a seroma may be misdiagnosed as an early recurrence. Wound infection is not uncommon. Many surgeons use routine prophylactic antibiotics but recent studies suggest little benefit even when mesh is used. Your Date Here Your Footer Here 79 Complications of inguinal hernia surgery In the longer term, hernia recurrence and chronic pain are the main concerns. No operation can be guaranteed to be recurrence free. Evidence shows that mesh repairs have lower recurrence rates than suture repairs, but there is no difference between the various mesh repairs and no difference between open and laparoscopic surgery. There is very strong evidence that specialist hernia surgeons will have lower recurrence rates whatever technique they use. Chronic pain, defined as pain present 3 months after surgery, is common after all forms of surgery. It is less common and less severe after laparoscopic surgery. Different types of pain have been described but the most severe is neuralgic pain due to nerve irritation. This may be the result of nerve injury at the time of operation or chronic irritation of nerves by suture material or mesh. Careful identification and protection of all three nerves passing along the inguinal canal reduces the incidence of neuralgic pain. This type of pain is also very uncommon after laparoscopic surgery that is performed at a deeper level away from the nerves. Some contribution to chronic pain may be due to the mesh, which can become embedded in a dense collagenous reaction with shrinkage. This causes tissue tension and rigidity. Rarely, damage to the testicular artery can lead to testicular infarction, perhaps the most serious complication of inguinal hernia surgery. There is no good evidence that hernia surgery has an effect on male fertility despite extensive study in this area. Your Date Here Your Footer Here 80 Complications of inguinal hernia surgery Your Date Here Your Footer Here 81  Femoral hernia Your Date Here Your Footer Here Basic anatomy The iliac artery and vein pass below the inguinal ligament to become the femoral vessels in the leg. The vein lies medially and the artery just lateral to the artery with the femoral nerve lateral to the artery. They are enclosed in a fibrous sheath. Just medial to the vein is a small space containing fat and some lymphatic tissue (node of Cloquet). It is this space which is exploited by a femoral hernia. The walls of a femoral hernia are the femoral vein laterally, the inguinal ligament anteriorly, the pelvic bone covered by the iliopectineal ligament (Astley Cooper’s) posteriorly and the lacunar ligament (Gimbernat’s) medially. This is a strong curved ligament with a sharp unyielding edge which impedes reduction of a femoral hernia. The female pelvis has a different shape to the male, increasing the size of the femoral canal and the risk of hernia. In old age, the femoral defect increases and femoral hernia is commonly seen in low-weight, elderly women. There is a substantial risk of developing a femoral hernia after a sutured inguinal hernia repair (Denmark Hernia Registry). Your Date Here Your Footer Here 83 Basic anatomy Your Date Here Your Footer Here 84 Femoral canal Topographic anatomy of the femoral canal region and surrounding regions. The femoral ring (yellow outline) forms the base of the femoral canal and is bounded by the inguinal ligament (anteriorly), lacunar ligament (medially), pectineal ligament (posteriorly), and fibrous septum of the femoral vein (laterally). The canal is wider in women. The cribriform fascia is not depicted in order to better visualize the saphenous opening. Your Date Here Your Footer Here 85  To remember the femoral triangle contents, think LaMe NAVEL: (from lateral to medial) femoral Nerve, Artery, Vein, Empty space (femoral canal → femoral hernia), Lymphatics Clinical pearl! Your Date Here Your Footer Here 86 Basic anatomy Your Date Here Your Footer Here 87 Femoral hernia Sagittal view of the male inguinal region at the level of the superior pubic ramus, medial to the epigastric vessels There is a protruding hernial sac (comprised of the transversalis fascia and parietal peritoneum) below the inguinal ligament but above the pubic bone, which, in the example shown, contains intestine. Your Date Here Your Footer Here 88 Diagnosis of femoral hernia Diagnostic error is common and often leads to delay in diagnosis and treatment. The hernia appears below and lateral to the pubic tubercle and lies in the upper leg rather than in the lower abdomen. Inadequate exposure of this area during routine examination leads to failure to detect the hernia. The hernia often rapidly becomes irreducible and loses any cough impulse due to the tightness of the neck. It may only be 1–2 cm in size and can easily be mistaken for a lymph node. As it increases in size, it is reflected superiorly and becomes difficult to distinguish from a medial direct hernia, which arises only a few centimetres above the femoral canal. A direct inguinal hernia leaves the abdominal cavity just above the inguinal ligament and a femoral hernia just below Your Date Here Your Footer Here 89  Although femoral hernias account for only about 5% of all hernias, they account for about 40% of all complicated hernias! Clinical pearl! Your Date Here Your Footer Here 90 Femoral hernia The patient has a left femoral and a right inguinal hernia. Your Date Here Your Footer Here 91 Diagnosis of femoral hernia Your Date Here Your Footer Here 92 Investigations In routine cases, no specific investigations are required. However, if there is uncertainly then ultrasonography or CT should be requested. In the emergency patient, bowel obstruction usually occurs and a plain radiograph is likely to show small bowel obstruction. All patients with unexplained small bowel obstruction should undergo careful examination for a femoral hernia. It is now common to perform CT scanning in cases of bowel obstruction primarily to exclude malignancy, but it can identify an obstructing femoral hernia missed by clinicians. Your Date Here Your Footer Here 93  There is no alternative to surgery for femoral hernia and it is wise to treat such cases with some urgency Clinical pearl! Your Date Here Your Footer Here 94  Ventral hernia Your Date Here Your Footer Here Ventral hernia This term refers to hernias of the anterior abdominal wall. Inguinal and femoral hernias are not included even though they are ventral. Lumbar hernia is included despite being dorsolateral. The European Hernia Society classification (2009) distinguished primary ventral from incisional hernia but did not include parastomal hernia. We have included parastomal hernia and traumatic hernia. Your Date Here Your Footer Here 96 Ventral hernia Your Date Here Your Footer Here 97 Ventral hernia Your Date Here Your Footer Here 98  Umbilical hernia Your Date Here Your Footer Here Umbilical hernia The umbilical defect is present at birth but closes as the stump of the umbilical cord heals, usually within a week of birth. This process may be delayed, leading to the development of herniation in the neonatal period. The umbilical ring may also stretch and reopen in adult life. This common condition occurs in up to 10% of infants, with a higher incidence in premature babies. The hernia appears within a few weeks of birth and is often symptomless, but increases in size on crying and assumes a classic conical shape. Your Date Here Your Footer Here 100 Congenital umbilical hernia Anterior abdominal wall of a newborn There is a mass ∼2 cm in diameter protruding through the umbilical orifice. This is the typical appearance of a congenital umbilical hernia, which characteristically increases in size on crying or coughing. Your Date Here Your Footer Here 101 Umbilical hernia in children Sexes are equally affected but the incidence in black infants is up to eight times higher than in white. Obstruction and/ or strangulation is extremely uncommon below the age of 3 years. Treatment Conservative treatment is indicated under the age of 2 years when the hernia is symptomless. Parental reassurance is all that is necessary. Of hernias 95% will resolve spontaneously. If the hernia persists beyond the age of 2 years it is unlikely to resolve and surgical repair is indicated. Your Date Here Your Footer Here 102 Umbilical hernia in children Your Date Here Your Footer Here 103 Umbilical hernia in adults Conditions that cause stretching and thinning of the midline raphe (linea alba), such as pregnancy, obesity and liver disease with cirrhosis, predispose to reopening of the umbilical defect. In adults, the defect in the median raphe is immediately adjacent to (most often above) the true umbilicus, although at operation this is indistinguishable. The term ‘paraumbilical hernia’ is commonly used. The defect is rounded with a well- defined fibrous margin. Small umbilical hernias often contain extraperitoneal fat or omentum. Larger hernias can contain small or large bowel but, even when very large, the neck of the sac is narrow compared with the volume of its contents. As a result, in adults, umbilical hernias that include bowel are prone to become irreducible, obstructed and strangulated. Your Date Here Your Footer Here 104 Paraumbilical hernia Anterior abdominal wall of an adult There is a protruding mass adjacent to the right lateral wall of the umbilical orifice. The right lateral wall and cavity of the umbilical orifice are obliterated by the mass, resulting in a crescent-shaped umbilicus. This is the typical appearance of a paraumbilical hernia. Your Date Here Your Footer Here 105 Umbilical hernia in adults Clinical features Patients are commonly overweight with a thinned and attenuated midline raphe. The bulge is typically slightly to one side of the umbilical depression, creating a crescent- shaped appearance to the umbilicus. Women are affected more than men. Most patients complain of pain due to tissue tension or symptoms of intermittent bowel obstruction. In large hernias, the overlying skin may become thinned, stretched and develop dermatitis. Treatment As a result of the high risk of strangulation, surgery should be advised in cases where the hernia contains bowel. Small hernias may be left alone if they are asymptomatic, but they may enlarge and require surgery at a later date. Surgery may be performed open or laparoscopically. Your Date Here Your Footer Here 106 Paraumbilical hernia Anterior abdominal wall of an adult There is a protruding mass adjacent to the superior wall of the umbilical orifice. The cavity of the umbilical orifice is obliterated by the mass, resulting in a crescent-shaped umbilicus. This is the typical appearance of a paraumbilical hernia. Your Date Here Your Footer Here 107 Umbilical hernia in adults Emergency repair of umbilical hernia Incarceration, bowel obstruction and strangulation are frequent because of the narrow neck and the fibrous edge of the defect in the midline raphe. Delay to surgery can lead to gangrene of the omentum or bowel. Large hernias are often multiloculated and there may be strangulated bowel in one component when other areas are clinically soft and a non-tender hernia. Your Date Here Your Footer Here 108  Epigastric hernia Your Date Here Your Footer Here Epigastric hernia These hernias arise through the midline raphe (linea alba) any where between the xiphoid process and the umbilicus, usually midway. When close to the umbilicus they are called supraumbilical hernias. Epigastric hernias begin with a transverse split in the midline raphe so, in contrast to umbilical hernias, the defect is elliptical. It has been hypothesised that the defect occurs at the site where small blood vessels pierce the linea alba or, more likely, that it arises at weaknesses due to abnormal decussation of aponeurotic fibres related to heavy physical activity. Epigastric hernia defects are usually less than 1 cm in maximum diameter and commonly contain only extraperitoneal fat, which gradually enlarges, spreading in the subcutaneous plane to resemble the shape of a mushroom. When very large they may contain a peritoneal sac but rarely any bowel. More than one hernia may be present. Your Date Here Your Footer Here 110 Epigastric hernia Herniation of intraabdominal contents through the linea alba, between the xiphoid process and the umbilicus. Your Date Here Your Footer Here 111 Epigastric hernia Clinical features The patients are often fit, healthy men aged between 25 and 40 years. These hernias can be very painful even when the swelling is the size of a pea, due to the fatty contents becoming nipped sufficiently to produce partial strangulation. The pain may mimic that of a peptic ulcer but symptoms should not be ascribed to the hernia until gastrointestinal pathology has been excluded. A soft midline swelling can often be felt more easily than seen. It may be locally tender. It is unlikely to be reducible because of the narrow neck. It may resemble a lipoma. A cough impulse may or may not be felt. Treatment Very small epigastric hernias have been known to disappear spontaneously, probably due to infarction of the fat. Small to- moderate-sized hernias without a peritoneal sac are not inherently dangerous and surgery should be offered only if the hernia is sufficiently symptomatic. Your Date Here Your Footer Here 112 Epigastric hernia Photograph of the abdomen of a female patient (lateral view) The epigastric region of the abdomen is bulging ventrally. This appearance is suggestive of an epigastric hernia. Your Date Here Your Footer Here 113  The most common cause of ‘recurrence’ is failure to identify a second defect at the time of original repair. Clinical pearl! Your Date Here Your Footer Here 114  Incisional hernia Your Date Here Your Footer Here Incisional hernia These arise through a defect in the musculofascial layers of the abdominal wall in the region of a postoperative scar. Thus they may appear anywhere on the abdominal surface. Incidence and aetiology Incisional hernias have been reported in 10–50% of laparotomy incisions and 1–5% of laparoscopic port-site incisions. Factors predisposing to their development are patient factors (obesity, general poor healing due to malnutrition, immunosuppression or steroid therapy, chronic cough, cancer), wound factors (poor quality tissues, wound infection) and surgical factors (inappropriate suture material, incorrect suture placement). An incisional hernia usually starts as disruption of the musculofascial layers of a wound in the early postoperative period. Often the event passes unnoticed if the overlying skin wound has healed securely. The classic sign of wound disruption is a serosanguineous discharge. Your Date Here Your Footer Here 116 Incisional hernia A bulging mass with an overlying midline laparotomy scar is visible in the epigastric region. These features suggest an incisional hernia. Your Date Here Your Footer Here 117  Many incisional hernias may be preventable with the use of good surgical technique. Clinical pearl! Your Date Here Your Footer Here 118 Incisional hernia Clinical features These hernias commonly appear as a localised swelling involving a small portion of the scar but may present as a diffuse bulging of the whole length of the incision. There may be several discrete hernias along the length of the incision and unsuspected defects are often found at surgery. Incisional hernias tend to increase steadily in size with time. The skin overlying large hernias may become thin and atrophic so that peristalsis may be seen in the underlying intestine. Vascular damage to skin may lead to dermatitis. Attacks of partial intestinal obstruction are common because there are usually coexisting internal adhesions. Strangulation is less frequent and most likely to occur when the fibrous defect is small and the sac is large. Most incisional hernias are broad-necked and carry a low risk of strangulation. Treatment Asymptomatic incisional hernias may not require treatment at all. The wearing of an abdominal binder or belt may prevent the hernia from increasing in size. Your Date Here Your Footer Here 119 Incisional hernia A bulging mass is visible in the epigastric region, with an overlying midline laparotomy scar. These features suggest an incisional hernia. Your Date Here Your Footer Here 120 Incisional hernia Your Date Here Your Footer Here 121 Incisional hernia Reducing the risk of incisional hernia The incidence of incisional hernia may be reduced by improving the patient’s general condition preoperatively where possible, e.g. weight loss for obesity or improving nutritional state for malnutrition. Closing the fascial layers with non-absorbable, or very slowly absorbable, sutures of adequate gauge is important. Traditional teaching was that sutures should be 1 cm deep and 1 cm apart. Recent work has shown that lower incisional hernia rates and reduced infection rates are gained when smaller and closer bites are used with a 2/0 suture rather than traditional heavier materials. There is no evidence that interrupted sutures are better or worse than continuous. However, if continuous suturing is used, the tissue bites must not be too near the fascial edge or pulled too tight because they may cut out. It has also been confirmed that the optimal ratio of suture length to wound length is 4:1 (Jenkins’ rule). If less length than this is used, the suture bites are too far apart or too tight and the converse applies if more length than this is used. Drains should be brought out through separate incisions and not through the wound itself because this leads to hernia formation. Recent reports have suggested that placement of a prophylactic mesh in patients at high risk of hernia formation will substantially reduce that risk. This has been reported in obese patients undergoing bariatric surgery and also to prevent parastomal herniation, which occurs in up to 50% of patients. Your Date Here Your Footer Here 122 Jenkin’s rule Your Date Here Your Footer Here 123  High risk of obstruction, low risk of strangulation! Clinical pearl! Your Date Here Your Footer Here 124  Spigelian hernia Your Date Here Your Footer Here Spigelian hernia These hernias are uncommon although are probably underdiagnosed. They affect men and women equally and can occur at any age, but are most common in elderly people. They arise through a defect in the spigelian fascia, which is the aponeurosis of transversus abdominis. Often these hernias advance through the internal oblique as well and spread out deep to the external oblique aponeurosis. The spigelian fascia extends between the transversus muscle and the lateral border of the rectus sheath from the costal margin to the groin, where it blends into the conjoint tendon. Most Spigelian hernias appear below the level of the umbilicus near the edge of the rectus sheath, but they can be found anywhere along the spigelian line There is a common misconception that they protrude below the arcuate line as a result of deficiency of the posterior rectus sheath at that level, but in fact the defect is almost always above the arcuate line. Your Date Here Your Footer Here 126 Spigelian hernia Herniation of intraabdominal contents through the semilunar line; commonly adjacent to the arcuate line (typically below the umbilicus) The semilunar line is the lateral border of the rectus abdominis. The arcuate line is the inferior border of the posterior rectus sheath. The lack of posterior rectus sheath below the arcuate line is assumed to predispose this region to hernia formation. Your Date Here Your Footer Here 127 Spigelian hernia Your Date Here Your Footer Here 128 Spigelian hernia In young patients they usually contain extraperitoneal fat only but in older patients there is often a peritoneal sac and they can become very large indeed. They have also been described in infants and may be congenital, reflecting incomplete differentiation of the mesenchymal layers within the abdominal wall. Clinical features Young patients usually present with intermittent pain, due to pinching of the fat, similar to an epigastric hernia. A lump may or may not be palpable because the fatty hernia is small and the overlying external oblique is intact. Older patients generally present with a reducible swelling at the edge of the rectus sheath and may have symptoms of intermittent obstruction. The diagnosis should be suspected because of the location of the symptoms and is confirmed by CT. Ultrasonography has the advantage that it can be performed in the upright patient because no defect may be visible with the patient lying down. Treatment Surgery is recommended because the narrow and fibrous neck predisposes to strangulation. Surgery can be open or laparoscopic. Your Date Here Your Footer Here 129 Spigelian hernia Photograph of the anterior abdominal wall of a female patient An ill-defined swelling is visible just lateral to the left rectus abdominis muscle (i.e., along the semilunar line). Examination of the mass showed a positive cough impulse. This is the typical appearance of a Spigelian hernia, an uncommon ventral hernia. Your Date Here Your Footer Here 130 Spigelian hernia Your Date Here Your Footer Here 131  Lumbar hernia Your Date Here Your Footer Here Lumbar hernia Most primary lumbar hernias occur through the inferior lumbar triangle of Petit bounded below by the crest of the ilium, laterally by the external oblique muscle and medially by latissimus dorsi. Less commonly, the sac comes through the superior lumbar triangle, which is bounded by the twelfth rib above, medially by sacrospinalis and laterally by the posterior border of the internal oblique muscle. Primary lumbar hernias are rare, but may be mimicked by incisional hernias arising through flank incisions for renal operations, or through incisions for bone grafts harvested from the iliac crest. Your Date Here Your Footer Here 133 Lumbar hernias Superior lumbar hernia (Grynfeltt hernia): herniation of intraabdominal contents through the superior lumbar triangle, the boundaries of which are the 12th rib, the erector spinae muscle, and the internal oblique muscle Inferior lumbar hernia (Petit hernia): herniation of intraabdominal contents through the inferior lumbar triangle, the boundaries of which are the iliac crest, the latissimus dorsi, and the external oblique muscle Your Date Here Your Footer Here 134 Lumbar hernia Your Date Here Your Footer Here 135 Lumbar hernia Differential diagnosis A lumbar hernia must be distinguished from: a lipoma; a cold (tuberculous) abscess pointing to this position; a pseudo-hernia due to local muscular paralysis. Lumbar pseudo-hernia can result from any interference with the nerve supply of the affected muscles, the most common cause being injury to the subcostal nerve during a kidney operation. Treatment The natural history is for these hernias to increase in size and surgery is recommended. Your Date Here Your Footer Here 136  Parastomal hernia Your Date Here Your Footer Here Parastomal hernia When surgeons create a stoma, such as a colostomy or ileostomy, they are effectively creating a hernia by bringing bowel out through the abdominal wall. The muscle defect created tends to increase in size over time and can ultimately lead to massive herniation around the stoma. The rate of parastomal hernia is over 50%. For patients, it is very difficult to manage a stoma that is lying adjacent to or atop a large hernia. Stoma appliance bags fit poorly leading to leakage. The ideal surgical solution for the patient is to rejoin the bowel and remove the stoma altogether, but this is not always possible. The stoma may be re-sited but further recurrence is likely. Your Date Here Your Footer Here 138 Parastomal hernia Abdominal wall of a patient with a stoma The abdomen is noticeably distended in the area around the stoma. This finding is a possible manifestation of a parastomal hernia. Your Date Here Your Footer Here 139 Parastomal hernia Various open suture and mesh techniques have been described to repair parastomal hernia but failure rates are high. Meshes are best placed in the retromuscular space. Laparoscopic repair is also possible using a large mesh with a central hole. It can be positioned around the bowel onto the parietal peritoneum. Recent reports (Millbourne et al.) have described the use of prophylactic mesh insertion at the time of formation of the stoma. A lightweight, polypropylene mesh is inserted in the retromuscular space so that the bowel passes through a hole in the mesh centre. Using this technique, parastomal hernia rates have been reduced significantly. Your Date Here Your Footer Here 140 THANK YOU! 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