Since umbilical hernias only account for 5% of all hernias, they are far less common than inguinal and incisional hernias and therefore arouse less surgical interest.
The incidence of umbilical hernia in preterm and small-for-date newborns weighing less than 1,500 grams is high. Since after obliteration of the umbilical vessels infants will develop a stable umbilical plate by the end of their second year, surgical treatment before this time is hardly ever needed.
In adults umbilical hernia will develop because of a number of risk factors: Obesity, pregnancy, metabolic connective tissue disorders due to genetic and exogenous factors (steroids, smoking), cirrhosis of the liver, cancer, and in old age weakening of the abdominal wall with diastasis recti abdominis. Spontaneous healing in hernias is rare, except for umbilical hernias in pregnancy.
The European Hernia Society classifies umbilical hernias according to the size of their fascial defect: small – fascial defect ≦ 2cm; moderate– fascial defect 2-4cm; large– fascial defect ≥ 4cm
Reliable assessment of the umbilical defect by physical examination and ultrasonography allows preoperative selection of the proper surgical method.
At present there are no guidelines on umbilical hernia repair. However, the available evidence allows the following recommendation to be made:
Small hernias
With a fascial defect of ≤ 0.5cm and the patient asymptomatic, watchful waiting rather than surgery is justified because of the very small risk of incarceration. However, if the patient reports recurrent complaints, surgery is indicated even in such a small finding. Gold standard in such a case, as well as in all fascial defects ≦ 2cm, is the Spitzy repair which closes the defect with a nonabsorbable suture (0 or 2/0).
Moderate hernias
For hernias with a diameter of 2–4 cm, buttressing the abdominal wall with a mesh is recommended. Various procedures are available: Open preperitoneal umbilical mesh plasty (PUMP) and the intraperitoneal onlay technique, which can be performed either as open (open IPOM) or laparoscopic (lap-IPOM).procedure.
Large hernias
If the fascial defect is bigger than 4cm, mesh repair is mandatory. Options are open or laparoscopic IPOM and retromuscular mesh repair similar to incisional hernia reparation.
Umbilical hernia in liver cirrhosis
Compared with healthy adults over 40% of all patients with decompensated liver cirrhosis have umbilical hernia, the repair of which is associated with increased mortality (8%) and morbidity (16-30%) as well as a high recurrence rate (up to 50%). Causes include:
- Impaired collagen synthesis due to liver failure
- Increased intraabdominal pressure or overstretching of the abdominal wall due to ascites
- In patients with liver failure general susceptibility to infection with risk of spontaneous bacterial peritonitis
- Problematic conditions of the herniated skin (maceration, ulceration)
- Regression of the abdominal strap muscles due to cirrhosis
- Risk of hernia rupture
- Ascites fistula
- Increased risk of incarceration
Unless there is an emergency situation (e.g., incarceration), elective hernia repair in cirrhotic patients with umbilical hernia should first be preceded by medical treatment (stabilization of liver function, medication to control ascites). In refractory ascites the indication for liver transplantation should be assessed, in which case the umbilical hernia would be repaired during the transplant procedure. If liver transplant is not indicated, measures for postoperative ascites control are required before hernia repair:
- Peritoneovenous shunt,
- CAPD catheter ("continuous ambulatory peritoneal dialysis") or
- Temporary ascites drainage through separate stab incision.
Two Robinson drains, introduced through separate bilateral stab wounds in the abdominal wall lateral to the surgical field, are sufficient for temporary perioperative ascites drainage. They should remain until wound healing is definitely complete (14 days).
Regarding mesh indication, patients with liver cirrhosis or ascites have to meet the same criteria as in uncomplicated umbilical hernias. There is no significant increase in wound healing disorders.