History
Most patients with Meckel diverticulum live their entire lives without any symptoms. This condition is most frequently diagnosed as an incidental finding when a barium study or laparotomy is performed for other abdominal conditions. [3]
Symptomatic Meckel diverticulum is virtually synonymous with a complication. This is estimated to occur in as many as 4-16% of patients. Complications are the result of obstruction, ectopic tissue, or inflammation. In a study of 830 patients of all ages, complications included bowel obstruction (35%), hemorrhage (32%), diverticulitis (22%), umbilical fistula (10%), and other umbilical lesions (1%).
In children, most series have historically noted that hematochezia is the most common presenting sign. [14] Bleeding in adults is much less common. [15, 16]
In another study of 65 pediatric patients over a 12-year period, isolated gangrene of the Meckel diverticulum was reported in 10 cases with obstruction. [17]
Hemorrhage
Acute lower gastrointestinal (GI) bleeding is secondary to hemorrhage from peptic ulceration. Such ulceration occurs when acid secreted by heterotopic gastric mucosa damages contiguous vulnerable tissue, oftentimes resulting in direct erosion of a vessel. Clinically, hemorrhage is usually noted to be substantial painless rectal bleeding. However, some patients may present with pain preceding the onset of hematochezia. The pain can be quite significant and often delays the correct diagnosis.
Hematochezia
Most often, painless rectal bleeding (hematochezia) occurs suddenly and tends to be massive in younger patients. [18] Bleeding occurs without prior warning and usually spontaneously subsides. The color of the stool often provides clinicians with a clue to determine the site of bleeding. This has been well addressed in a classic description of the types of rectal bleeding associated with Meckel diverticulum. [19]
The prevalence of different types of bleeding has been described as follows:
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Dark red (maroon): 40%
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Bright red: 35%
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Bright red or dark red: 12%
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Dark red or tarry: 6%
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Tarry: 7%
When bleeding is rapid, stools are bright red or have an appearance like currant jelly. When slow bleeding occurs, the stools are black and tarry.
Obstruction
Abdominal pain may be reported when the presentation is related to an obstruction or inflammation. Relatively recent reports have brought into question the belief that intestinal obstruction in pediatrics secondary to Meckel diverticulum is not very prevalent, with some series reporting a prevalence of 25-40% of pediatric complications. Obstruction is the most common complication in adults. In children or adults, obstruction can be secondary to various mechanisms. [3] Mechanisms include the following (none of these have clinical features that are pathognomonic, and the precise etiology is rarely known preoperatively):
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Omphalomesenteric band (most frequent cause)
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Internal hernia through vitelline duct remnants
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Volvulus occurring around vitelline duct remnants
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T-shaped prolapse of both efferent and afferent loops of intestine through a persistent vitelline duct fistula at the umbilicus in a neonate
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Intussusception (when Meckel diverticulum itself acts as a lead point for an ileocolic or ileoileal intussusception)
Like other diverticula in the body, Meckel diverticulum can become inflamed. Diverticulitis is usually seen in older patients but has also been observed in children. Meckel diverticulum is less prone to inflammation than the appendix, because most diverticula have a wide mouth, have very little lymphoid tissue, and are self-emptying. The clinical presentation includes abdominal pain in the periumbilical area that radiates to the right lower quadrant. Persistence of periumbilical pain or a history of bleeding per rectum may be helpful in distinguishing this entity from appendicitis.
Unusual presentations
Unusual presentations of Meckel diverticulum have also been reported. A rare cause of abdominal pain was inversion without intussusception. [20] Another case report described a perforation as a result of blunt abdominal trauma. [21] This report emphasized the importance of including perforation of Meckel diverticulum in the differential diagnosis of abdominal trauma. [21] Another case report described a rare presentation of pyogenic liver abscess due to an infected Meckel diverticulum. Perforated Meckel diverticulum can rarely present as an abdominal abscess or as a pyogenic liver abscess. The authors conclude that that elective resection of a Meckel diverticulum should be considered in the presence of a pyogenic liver abscess if no other etiologies are identified, [22] but others include sarcoma, [23] carcinoid tumor, [24] adenocarcinomas, and Burkitt lymphoma, as well as additional rare lesions. [21]
Foreign bodies
Foreign bodies can become confined in Meckel diverticulum and lead to obstruction or perforation. The most common foreign body that causes perforation in Meckel diverticulum is ingested bone fragments (58%), followed by wood splinters (14%), food (12%), pin/needles (9%), and miscellaneous (7%). [25] One case report emphasized how chronic right lower quadrant abdominal pain could be related to a Meckel diverticulum: After years of intermittent nonspecific abdominal symptoms, an adolescent presented with signs of small bowel obstruction and was found to have a large enterolith in an inflamed Meckel diverticulum. [26] In a case report by Hussein et al, a phytobezoar caused obstruction of a Meckel diverticulum in a patient on high vegetarian diet. [27] The authors suggested that the intestinal dysmotility and poor coordination of the peristaltic waves at the site of the Meckel diverticulum could produce decreased ileal motility and slow intraluminal flow with impaction of foreign objects and stickiness of boluses of food. [27]
Ingestion of multiple foreign bodies is more commonly seen in individuals with psychiatric illness or intellectual disabilities. One case study described a child with autism spectrum disorder who presented to the emergency department with complaints of acute onset of abdominal pain and bilious vomiting. [28] Abdominal radiographs revealed evidence for obstruction with dilated small bowel with air-fluid levels. A computed tomography scan revealed foreign objects in the distal small bowel, with dilatation of the proximal intestine and decompressed bowel distally. During exploratory laparotomy, a Meckel diverticulum was found containing multiple foreign objects. [28]
Physical Examination
Most patients with Meckel diverticulum are asymptomatic. However, patients can present with various clinical signs, including peritonitis or hypovolemic shock. The three most common symptomatic presentations are gastrointestinal (GI) bleeding, intestinal obstruction, and acute inflammation of the diverticulum.
When a severe bleeding episode occurs, the patient can present in hemorrhagic shock. Tachycardia is an early clinical sign of hemorrhagic shock, but pale conjunctivae and orthostatic hypotension may actually precede this.
Most patients with intestinal obstruction present with abdominal pain, bilious vomiting, generalized abdominal tenderness, distention, hypoactive or hyperactive bowel sounds, peritoneal signs, and rebound tenderness upon examination. Patients may develop a palpable abdominal mass. Occasionally, when patients do not present early or if the diagnosis is missed, the obstruction can progress to intestinal ischemia or infarction; the latter manifests with acute peritoneal signs and lower GI bleeding.
Patients with diverticulitis present with either focal or diffuse abdominal tenderness. Usually, abdominal tenderness is more marked in the periumbilical region than that from the pain of appendicitis. Children may present with abdominal guarding and rebound tenderness, in addition to abdominal tenderness. Abdominal distention and hypoactive bowel sounds are late findings. Suppurative Meckel diverticulum can present in a child with abdominal pain and periumbilical cellulitis. [29] Rarely, Meckel diverticulum has been reported to become incarcerated (Littre hernia) in the inguinal, [30] femoral, or obturator hernial sacs or even incisional defects.
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Pediatric Meckel Diverticulum. Anteroposterior view of an abdominal radiograph showing multiple dilated loops of a small bowel with air-fluid levels.
