Stefano Guandalini, Anil Dhawan and David Branski (eds.)Textbook of Pediatric Gastroenterology, Hepatology and Nutrition10.1007/978-3-319-17169-2_49

49. Meckel’s Diverticulum

Ashish P. Desai¹

(1)

Department of pediatric Surgery, King’s College Hospital, Denmark Hill, SE5 9RS London, UK

Ashish P. Desai

Email: ashishdesai@nhs.net

Keywords

Meckel’s diverticulumTrue diverticulumBleeding PRTechnetium scanIntussusceptionIntestinal obstruction

Introduction and History

Meckel’s diverticulum (MD) is one of the commonest diverticulum in human beings. It occurs in 2 % of the population. As Charles Mayo described—“Meckel’s diverticulum is frequently suspected, often looked for, and seldom found”.

Heladnus first described it in 1598 [1]. Ruysch and Levater described the diverticulum much before Meckel’s description [2]. However, Johann Friedrich Meckel described the diverticulum in detail in 1809 and is credited with the first detailed description [3].

In 1962, Harper et al. suggested that as 99mTc pertechnetate is concentrated by gastric mucosa, the MD containing the gastric mucosa should be identifiable scintigraphically using 99mTc pertechnetate [4]. However, most MD may be identified intra-operatively due to its varying presentation of intestinal obstruction caused by either band with volvulus or intussusception, umbilical discharge and diverticulitis.

Embryology

During the first few weeks of gestation, primitive yolk sac divides into primitive midgut and yolk sac. Omphalo-mesenteric duct or vitello-intestinal duct connects the two. This structure usually regresses between 5th and 7th week of intrauterine life. Failure of regression leads to various presentations of patent vitello-intestinal duct (VI duct). Persistence of the tube proximally causes MD .

Incidence

MD is usually described by rule of 2. Common dictum is that it is present in around 2 % of the population. It is 2 in. long and found around 2 ft from the Ileo-caecal (I/C) valve. It may contain two types of heterotopic mucosa—gastric or pancreatic.

However, these are more generalisations than fact. Incidence of symptomatic MD is thought to be around 4 % in the first 3 years of life. Following that, the incidence decreases. Prevalence of MD during postnatal autopsies is 1.23 % [5].

Associated Anomalies

MD is usually an isolated condition. However, patients with Hirschsprung’s disease , Down syndrome, oesophageal atresia, duodenal atresia, malrotation and congenital cardiac abnormalities show increased incidence [6].

Gross and Microscopic Anatomy

MD arises on the anti-mesenteric border of the ileum. Its distance from I/C valve is variable and is thought to be anywhere from 30 to 120 cm. Hence, during surgery, it is advisable to inspect at least 150 cm of terminal ileum. It has its own blood supply from persistent vitelline artery which is a branch of superior mesenteric artery.

On histology, it usually resembles the ileum. As it is a true diverticulum , it contains all layers of a normal intestine, that is, mucosa, submucosa, muscularis propria and serosa. However, it may contain heterotopic mucosa—either gastric or pancreatic tissue. Incidence of gastric mucosa occurs in around 9 % of the patients. Pancreatic mucosa is seen in 2.5 % of patients [7]. Various studies have also showed presence of carcinoid, lipoma, leiomyoma or enterolith.

Variations of Patent VI Duct Anomalies

VI duct anomalies occur due to variation of persistence of VI duct remnant and its attachment to the umbilicus.

Various anomalies are

MD—persistent proximal part of the VI duct

Isolated fibrous band—persistent remnant of whole VI duct

Omphalo-mesenteric fistula—presents as stoma at the umbilicus [8] or prolapse through the umbilicus [9]

Enterocyst—persistent middle part of the fistula.

Meckel’s diverticulum may also have attached fibrous band.

Clinical Features

Most MDs are asymptomatic throughout life. In symptomatic cases, presentation varies with age.

Neonatal

In neonates, the presentation is usually due to persistent VI duct presenting as either a discharging sinus at the umbilicus [8] or a prolapsing VI duct remnant [10, 11]. Other presentations may be due to a band with associated volvulus causing partial or complete obstruction. Perforation is rare.

Pediatric Age Group

In pediatric age group, presentation varies between gastrointestinal (GI) bleeding , Intestinal obstruction and inflammation.

GI Bleeding

GI bleeding is the commonest presentation in children below 2 years of age. It is usually the major lower GI bleed, which is painless or associated with minimal pain. The bleeding is associated with gastric heterotopia in majority of cases [12]. Bleeding is due to peptic ulcer in the surrounding normal ileal tissue.

In cases where the gastric mucosa is absent, bleeding is usually attributable to other causes like intussusception or gastritis.

Management of major GI bleed should include—assessment of hemodynamic stability, differentiation between upper and lower GI bleeding and then to determine the diagnosis and site of the bleeding.

In children suspected to have MD, after adequate fluid resuscitation, they should be started on H2 blockers like ranitidine or famotidine. Currently, proton pump inhibitors like omeprazole or lansoprazole are routinely used. Once bleeding is controlled, 99 m technetium-pertechnetate scan should be done to look for the diagnosis of MD. If diagnosed, they should be resected.

Diverticulitis

Inflammation of the MD may be the presenting sign in 10–20 % of children. Children are usually older. They are often mistaken as acute appendicitis. During surgery, inflamed MD is identified and should be excised.

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