An epigastric hernia is a protrusion of preperitoneal fat through a gap in the decussating fibres of the supraumbilical portion of the linea alba. The defect usually occurs where the linea alba is pierced by a blood vessel. A peritoneal sac may accompany fat through the defect and may contain omentum but only rarely bowel. This hernia may present at any age but is most common in adult males under the age of 40. An epigastric hernia is present in 5 per cent of individuals at autopsy; 25 per cent of individuals have multiple hernias.

The majority of epigastric hernias are asymptomatic. Vague upper abdominal pain and nausea associated with epigastric tenderness may be present. These symptoms tend to be more severe when the patient is lying down, owing to traction on the hernial contents. A lump, which may be tender, is usually palpable in non-obese subjects. Gangrene of the contents of the hernia occasionally occurs, producing severe epigastric tenderness and localized muscular rigidity. These features may mimic those of an intra-abdominal catastrophe.

The presence of a non-tender epigastric hernia should never be considered to be an adequate explanation for dyspepsia or epigastric pain except following extensive investigation of the upper gastrointestinal tract. Conversely, in obese patients with chronic upper abdominal symptoms an epigastric hernia may remain undiagnosed for years because it is often not palpable.

Symptomatic hernias and those greater than 2 cm in diameter are best repaired. The procedure entails mobilization and reduction of the protruding fat or peritoneal sac followed by closure of the defect in the linea alba with interrupted non-absorbable sutures.

Three distinct types of hernia occur around the umbilicus: congenital (omphalocele or exomphalos), infantile umbilical hernia, and adult paraumbilical hernia.

During intrauterine development the amniotic sac contains the embryological midgut. At 10 weeks of gestation the gut normally returns to the abdominal cavity. When this fails to occur normal rotation and fixation of the intestine is prevented. At birth the umbilicus is absent and a broad funnel-shaped defect in the abdominal wall is present through which viscera protrude into the umbilical cord. Peritoneum, but not skin, covers the protruding viscera. The peritoneal sac may rupture during, or shortly after birth. Defects less than 5 cm in diameter usually contain gut only (exomphalos minor) whereas defects greater than 5 cm usually contain liver and other viscera (exomphalos major). This condition occurs in 1 in 5000 births and is associated with other serious congenital abnormalities in 60 per cent of cases.

Urgent surgical repair should be performed before rupture of the sac occurs or infection supervenes. If the peritoneal sac has ruptured it is important to keep the bowel moist and protected with saline-soaked packs until prompt surgical repair can be performed. In exomphalos minor the viscera can usually be returned to the abdominal cavity with closure of the abdominal wall and skin defects. In exomphalos major the abdominal cavity is usually too small to allow return of the viscera and primary closure (attempts to achieve this usually resulting in respiratory embarrassment, obstruction of venous return, or intestinal obstruction). Initial treatment usually aims to cover the peritoneal sac with an artificial material such as a silastic bag which is sutured to the edges of the defect. This is followed by reduction of the contents as a staged procedure with eventual skin closure. Inevitably an incisional hernia results, which can be repaired in later childhood. Following such a staged closure it may be weeks or even months before normal intestinal function occurs and prolonged intravenous feeding may be necessary.

At birth, following division of the umbilical cord the stump heals by granulation and scarring to fuse with the umbilical ring of the abdominal wall. Failure of fusion allows a peritoneal sac to protrude, usually at the superior margin of the ring. The infantile hernia, as opposed to the congenital type, is always covered with skin. This hernia is present in 10 per cent of caucasian infants (male:female ratio = 2:1) and 90 per cent of black infants. It is most common in premature babies.

This hernia is usually symptomless and presents as an easily reducible lump which becomes more prominent during crying and coughing. It rarely enlarges over time and will disappear in 93 per cent of children by the age of 2 years. The hernial contents usually remain virtually unchanged in size until just before final closure. Tapes, binders, and trusses to reduce the hernial contents are no longer generally advocated as they may lead to skin infection or necrosis.

Incarceration or strangulation of this hernia is extremely rare. Surgical repair is indicated if this occurs or if the hernia persists beyond the age of 2 years. Repair entails mobilization and reduction of the hernial sac followed by closure of the defect with one or two layers of interrupted non-absorbable sutures.

This is an acquired hernia which occurs following disruption of the linea alba above, or much less commonly below, the umbilical cicatrix. Stretching of the abdominal wall due to obesity, multiple pregnancy, and ascites favour the development of this hernia. Deposition of fat in the abdominal wall in the obese may also be an aetiological factor. The condition usually occurs after the age of 35 and is five times more common in females.

This hernia tends to enlarge progressively over time and may produce localized dragging pain (Fig. 1) 1440. Gastrointestinal symptoms commonly occur due to traction between the hernial contents and the stomach and transverse colon. When the hernial sac contains bowel, colic due to intermittent intestinal obstruction is common. Intertrigo and necrosis of the skin may occur in patients with larger hernias.

The paraumbilical hernia usually has a small neck. Incarceration and strangulation are therefore common. Early operation is advisable. Repair comprises mobilization and excision of the sac following reduction of its contents. This is usually followed by the construction of flaps of rectus sheath and linea alba above and below the defect. The lower flap is then sutured under the upper flap. Finally, the upper flap is sutured anteriorly to produce a double-breasted repair (the Mayo repair).

Nyhus LM, Condon RE, eds. Hernia. 2nd edn. Philadelphia: JB Lippincott, 1978.