Meckel diverticulum is the most commonly occurring congenital malformation of the gastrointestinal tract. However it is an uncommon cause of abdominal symptoms in adults. It is estimated to cause complications in approximately 4–7% of cases2–4
and of these 40% occur in children under the age of 10 years.5
It exists due to the persistence of the vitello-intestinal duct and is composed of all layers of the bowel. Therefore, it is a true diverticulum.6
Generally it is 1–12 cm in length and is found 45–90 cm from the ileocaecal valve. It is estimated to be present in approximately 2% of the population.1
The diverticulum itself is asymptomatic but clinical manifestations arise secondary to complications. Diverticulum longer than 2 cm in males under the age of 40 years are thought to give rise to the highest number of complications.7
Gastrointestinal haemorrhage is the most common complication in paediatric patients, occurring most often in male patients under the age of 2 years. It can manifest anywhere along a spectrum extending from chronic episodes of haematochezia to massive acute blood loss in a shocked patient.1
Gastrointestinal bleeding is less common amongst the adult population.6
In adults the most common complications seen are obstruction, inflammation and perforation.6,7
Obstruction may be secondary to a number of mechanisms. It may be secondary to inflammation, adhesions or the diverticulum may form the lead point of an intussusception.1,8
Less frequently a tumour, arising from the diverticulum, will obstruct the bowel lumen. The diverticulum rarely can become incarcerated within a hernia.1,8
Even more uncommonly, a volvulus may develop around a persistent vitello-intestinal duct extending between the umbilicus and a Meckel diverticulum.9
Meckel diverticulum, like other diverticulum, are vulnerable to inflammation potentially resulting in perforation. Those diverticulum with narrow necks are particularly vulnerable as they are more prone to become obstructed by enteroliths leading to stasis within the diverticulum and consequentially inflammation.1
Diverticulitis most commonly presents with abdominal pain, which often mimics appendicitis. A perforation will result in peritonitis.
The clinical challenge is differentiating a Meckel diverticulum from other more common conditions. As our case demonstrates, patients are often treated initially for other conditions, such as diverticulitis or appendicitis, with the correct diagnosis only being made at operation.
Plain abdominal films may demonstrate appearances typical of obstruction, perforation or may identify an enterolith but these findings are highly non-specific.10
CT is certainly of use in diagnosing small bowel obstruction. Generally, dilated small bowel loops are seen proximal to the point of obstruction with collapsed or normal bowel loops distal to the same site and CT has a high sensitivity and specificity for these signs.5,11
However, it is generally of little use in diagnosing a Meckel diverticulum as it is usually impossible to differentiate between the diverticulum and intestinal loops.12
Technetium scanning can be of use where ectopic gastric mucosa is present and angiography may be helpful in identifying bleeding originating from a Meckel diverticulum.5,12
- Meckel diverticulum is the most commonly occurring congenital malformation of the gastrointestinal tract; however, complications are uncommon but carry a high mortality and morbidity.
- Clinically, complications can present in a multitude of differing ways and often present in similar ways to other more common causes of abdominal symptoms.
- CT scanning is of value in diagnosing small bowel obstruction but is very unlikely to accurately diagnose a Meckel diverticulum.
- Current imaging modalities offer very little possibility of accurate pre-operative diagnosis.
- The possibility of a Meckel diverticulum should not be forgotten and physicians should consider it when assessing patients presenting with gastrointestinal bleeding, abdominal pain or small bowel obstruction.