Pediatric Meckel Diverticulum 

Updated: Oct 20, 2017
Author: Simon S Rabinowitz, MD, PhD, FAAP; Chief Editor: Carmen Cuffari, MD 

Overview

Background

Meckel diverticulum (also referred to as Meckel's diverticulum) is the most common congenital abnormality of the small intestine; it is caused by an incomplete obliteration of the vitelline duct (ie, omphalomesenteric duct). Although originally described by Fabricius Hildanus in 1598, it is named after Johann Friedrich Meckel, who established its embryonic origin in 1809.[1]

Despite the availability of modern imaging techniques, diagnosis is challenging. Although Meckel diverticulum is usually asymptomatic, two types of complications can require clinical attention. One type involves ectopic mucosal tissue and most often leads to GI bleeding in younger children. In the second type, an obstruction, inflammation, or, rarely, perforation of the bowel is present.

Pathophysiology

The yolk sac is the first element to be formed within the gestational sac. It is involved in maternal-fetal transfer of nutrients in early gestation during the critical period of organogenesis. Early in embryonic life, the fetal midgut receives its nutrition from the yolk sac via the omphalomesenteric/vitelline duct. The duct then undergoes progressive narrowing and usually disappears by 7 weeks' gestation. When the duct fails to fully obliterate, different types of vitelline duct anomalies appear. Examples of such anomalies include (1) a persistent vitelline duct (appearing as a draining fistula at the umbilicus); (2) a fibrous band that connects the ileum to the inner surface of the umbilicus; (3) a patent vitelline sinus beneath the umbilicus; (4) an obliterated bowel portion; (5) a vitelline duct cyst; and, most commonly (97%) Meckel diverticulum, which is a blind-ending true diverticulum that contains all of the layers normally found in the ileum.[2] The tip of the diverticulum is free in 75% of cases and is attached to the anterior abdominal wall or another structure in the remainder of cases.

Enterocystomas, umbilical sinuses, and omphaloileal fistulas are among the other congenital anomalies associated with Meckel diverticulum.

The diverticulum is usually supplied by the omphalomesenteric artery (a remnant of the vitelline artery), which arises from the ileal branch of the superior mesenteric artery. Usually, the artery terminates in the diverticulum; however, it has been reported to continue up to the abdominal wall in some cases. Rarely, these blood vessels persist in the form of fibrous remnants that run between the Meckel diverticulum and the abdominal wall or small bowel mesentery.

A rare case of Meckel diverticulum reported was associated with other umbilical anomalies; a 4-year-old boy presented with abdominal pain, vomiting, and constipation.[3]  Upon surgical exploration, he was found to have a band arising from a Meckel diverticulum, causing obstruction of the terminal ileum. An urachal cyst at the umbilicus was attached to the Meckel diverticulum at one end and to the urinary bladder on the other end through a patent urachus.

Although Meckel diverticulum almost always occurs on the antimesenteric border of the ileum, case reports have described a mesenteric location. As per the rule of 2s, it is usually 2 feet (40-60 cm) proximal to the ileocecal valve, 2 cm wide (and is 3 cm long), found in 2% of the population,[4] often presents before age 2 years, is twice as likely to be symptomatic in boys, and contains ectopic mucosa about half the time. Meckel diverticulum is typically lined by ileal mucosa, but other tissue types are also found with varying frequency.

The heterotopic mucosa is most commonly gastric. This is important because peptic ulceration of this or adjacent mucosa can lead to painless bleeding, perforation, or both. In one study, heterotropic gastric mucosa was found in 62% of cases, pancreatic tissue was found in 6%, both pancreatic tissue and gastric mucosa were found in 5%, jejunal mucosa was found in 2%, Brunner tissue was found in 2% and both gastric and duodenal mucosa were found in 2%.[2] Rarely, colonic, rectal, endometrial, and hepatobiliary tissues have been noted.

Epidemiology

Frequency

United States

The prevalence of Meckel diverticulum is usually noted to be approximately 2% of the population,[4] but published series range from 0.2-4%.[5] Complications are only seen in about 5% of those with the anomaly. In a retrospective survey of 43 children's hospitals in the United States, 815 children had a Meckel diverticulectomy during a 2-year span. Slightly more than half (60%) were symptomatic and the remainder were incidental in children who had laparotomy for a different reason.[6]

International

Prevalence figures similar to those found in the United States have been reported in Europe and Asia.

Mortality/Morbidity

See Complications.

Race

One study investigated the Pediatric Hospital Information System (PHIS) database to identify demographics of patients with ICD-9 diagnoses of Meckel diverticulum and a procedure code for Meckel diverticulectomy. Data from a 9-year period (2004-2012) was analyzed for age, payer, ethnicity and symptoms. The database included patients admitted to 44 children’s hospitals in the United States. The ethnic distribution of symptomatic Meckel diverticulum was 63.4% white, 4.7% African-American, 16.4% Hispanic, 3.9% Asian, and 11.6% other.[7]

Sex

Although no sex-based difference was reported in studies that evaluated this condition as an incidental finding during operations or autopsies, males are as much as 3-4 times more prone to complications than females. In a large series of cases from 2007-2008, Meckel diverticulectomy was 2.3 times more common in boys and boys accounted for 74% of the primary cases.[6]

Age

The classic presentation in children is considered to be painless rectal bleeding in a toddler younger than 2 years. One large series found that 53% had surgery before their fourth birthday. However, the largest group (slightly more than 30%) were younger than one year.[6] Although most other pediatric cases occur in patients aged 2-8 years, many continue to present with hematochezia.

Although younger children have been reported to usually present with hematochezia and adults with obstruction, the same recent series of 815 pediatric (< 8 y) cases found that a primary diverticulectomy was performed more commonly (30%) for obstruction, than bleeding (27%) and that a substantial proportion (19%) had intussusception[6] About one quarter did not have a clear cut diagnosis.

A recent literature review of Meckel Diverticulum in the neonatal period found that the most common manifestations in this age were bowel obstruction (58.3%) and pneumoperitoneum (33.3%). In addition, in both term and preterm neonates, males were even more frequently affected than females, with a male-to-female ratio of 6.5:1. Other neonatal presentations include perforation, intussusception, segmental ileal dilation, ileal volvulus, and massive hematochezia.[6]

In adults, obstruction and inflammation are more common presentations than lower GI bleeding. Several population-based studies have reported a decreased incidence of complications with increasing age, although other studies have not. Therefore, the issue of incidental diverticulectomy in older patients remains controversial.

 

Presentation

History

Most patients live their entire lives without any symptoms. Meckel diverticulum is most frequently diagnosed as an incidental finding when a barium study or laparotomy is performed for other abdominal conditions.[2]

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 one 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.[8] Bleeding in adults is much less common.[9, 10]

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.[11]

Acute lower GI bleeding is secondary to hemorrhage from peptic ulceration. Such ulceration occurs when acid secreted by heterotopic gastric mucosa damages contiguous vulnerable tissue, often times 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.

Abdominal pain may be reported when the presentation is related to an obstruction or inflammation. Recent reports have brought into question the belief that intestinal obstruction in pediatrics secondary to Meckel's 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.[2]  Mechanisms include the following (none of these have clinical features that are pathognomonic, and the precise etiology is rarely known preoperatively):

  • Omphalomesenteric band (most frequent cause)

  • Internal hernia through vitelline duct remnants

  • Volvulus occurring around vitelline duct remnants

  • T-shaped prolapse of both efferent and afferent loops of intestine through a persistent vitelline duct fistula at the umbilicus in a neonate

  • 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 been seen 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 of Meckel diverticulum have also been reported. A rare cause of abdominal pain was inversion without intussusception.[12]  Another case report described a perforation as a result of blunt abdominal trauma. This report emphasized the importance of including perforation of Meckel diverticulum in the differential diagnosis of abdominal trauma.[13] . 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.[14] but others include sarcoma,[15]  carcinoid tumor,[16] adenocarcinomas, and Burkitt lymphoma, as well as additional rare lesions.[13]

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%).[17]

In a case report by Hussein et al, a phytobezoar caused obstruction of a Meckel diverticulum in a patient on high vegetarian diet. They 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.[18]

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 ED with complaints of acute onset of abdominal pain and bilious vomiting. Abdominal radiographs revealed evidence for obstruction with dilated small bowel with air fluid levels. A CT scan revealed foreign objects in the distal small bowel, with dilation of the proximal intestine and decompressed bowel distally. Exploratory laparotomy was performed, and a Meckel diverticulum was found containing multiple foreign objects.[19]

Most often, painless rectal bleeding (hematochezia) occurs suddenly and tends to be massive in younger patients.[20]  Bleeding occurs without prior warning and usually spontaneously subsides. The color of the stool often provides physicians 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.[21]

Prevalence of different types of bleeding has been described as follows:

  • Dark red (maroon) - 40%

  • Bright red - 35%

  • Bright red or dark red - 12%

  • Dark red or tarry - 6%

  • 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.

Physical

Although most patients are asymptomatic, patients can present with various clinical signs, including peritonitis or hypovolemic shock. The 3 most common symptomatic presentations are 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, distension, 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 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.[22]  Rarely, Meckel diverticulum has been reported to become incarcerated (Littre hernia) in the inguinal,[23] femoral, or obturator hernial sacs or even incisional defects.

Causes

Meckel diverticulum is caused by the failure of the omphalomesenteric duct to completely obliterate at 5-7 weeks' gestation, followed by one of the various complications listed above.

Complications

Complications are listed above but fall into the categories of bleeding, obstruction, or inflammation (diverticulitis), which could be related to foreign bodies and or tumors.

 

DDx

 

Workup

Approach Considerations

A rapid assessment of any child with significant bleeding or signs of small bowel obstruction, ischemia, or inflammation. Meckel diverticulum is a relatively uncommon etiology for any of these complications but must always be considered in the differential diagnosis.  

Laboratory Studies

Routine laboratory findings, including CBC, electrolyte levels, glucose, BUN, creatinine levels, and coagulation screen results, are not helpful in establishing the diagnosis of Meckel diverticulum but are necessary to manage a patient with GI bleeding along with a type and cross.

Hemoglobin and hematocrit levels are low in the setting of anemia or significant bleeding. In one series, 58% of children had average hemoglobin levels of less than 8.8 g/dL.

A prospective linear observational study of 73 children with a diagnosis of symptomatic Meckel diverticulum compared mean hemoglobin level before onset of symptoms and at presentation of rectal bleeding. The study demonstrated a correlation of 58% between Meckel diverticulum and hematochezia with a drop in hemoglobin of more than 2g/dL.[24]

Ongoing bleeding from a Meckel diverticulum can cause iron deficiency anemia. However, megaloblastic anemia can also be seen due to vitamin B12 or folate deficiency. These can occur secondary to small bowel overgrowth if chronic dilation and/or stasis related to the diverticulum is present. Low albumin and low ferritin levels may erroneously lead to a diagnosis of inflammatory bowel disease.

Imaging Studies

According to Mayo, "Meckel's Diverticulum is frequently suspected, often looked for, and seldom found." Preoperative diagnosis is difficult, especially if the presenting symptom is not GI bleeding. In one series, patients often had a correct preoperative diagnosis if the presenting symptom was GI bleeding, but only 11% of preoperative diagnoses were correct if other symptoms predominated.[25]

History and physical examination are of paramount importance for establishing a clinical diagnosis. Imaging studies are performed to confirm a clinical suspicion of Meckel diverticulum.

Plain radiography of the abdomen is of limited value. It may reveal evidence of nonbleeding complications, including enteroliths and signs of intestinal obstruction, such as air or air-fluid levels (see the image below), or perforation.

Anteroposterior view of abdominal radiograph showi Anteroposterior view of abdominal radiograph showing multiple dilated loops of a small bowel with air-fluid levels.

When a patient has GI bleeding suggestive of Meckel diverticulum, the diagnostic evaluation should focus on Meckel scanning, a technetium-99m pertechnetate scintiscan (0.2mCi/kg in children, up to the dosage used in adults, 10-20mCi in adults). The pertechnetate is taken up by heterotopic gastric mucosa. Because bleeding from the Meckel diverticulum is related to acid induced damage of mucosa adjacent to the parietal cell containing tissue, it is always included early in the work-up.[26]

After intravenous injection of the isotope, the gamma camera is used to scan the abdomen. This procedure usually lasts approximately 30 minutes. Gastric mucosa secretes the radioactive isotope; thus, if the diverticulum contains this ectopic tissue, it is recognized as a hot spot.

The Meckel scan is the preferred procedure because it is noninvasive, involves less radiation exposure, and is more accurate than an upper GI and small-bowel follow-through study.

Based on a retrospective review of Meckel scans performed from 1993-2011, the Meckel scan has a reported sensitivity of 94% and a specificity of 97% in children.

In adults, in whom GI bleeding is a much less common presentation, the scan has a lower sensitivity (62.5%), a much lower specificity (9%), and a lower accuracy (46%)[27]

Because the Meckel scan is specific for gastric mucosa (ie, in the stomach or ectopic) and not specifically diagnostic of Meckel diverticulum, false positive results occur whenever ectopic gastric mucosa is present. Duodenal ulcer, small intestinal obstruction, some intestinal duplications, ureteric obstruction, aneurysm, and angiomas of the small intestine have yielded positive results. False negative results can occur when gastric mucosa is very slight or absent in the diverticulum, if necrosis of the diverticulum has occurred, or if the Meckel is superimposed on the bladder.[28]

Accuracy of the scan may be enhanced with administration of cimetidine, glucagon, and pentagastrin. Cimetidine enhances the uptake and blocks the secretion of technetium-99m pertechnetate from ectopic gastric mucosa.[29]  This helps to improve the lesion to background ratio in enhancing a Meckel scan. Pentagastrin also enhances uptake of the isotope but also increases peristalsis, attenuating its value. Glucagon is used to decrease peristalsis, thus allowing the signal to be taken up during a longer exposure time. One strategy uses both pentagastrin and glucagon. With newer imaging technology, false-positive and false-negative rates have declined.

Barium studies have largely been replaced by other imaging techniques; however, if a barium study is indicated, it should never precede the technetium-99m scan because barium may obscure the hot spot.

A bleeding scan can be performed to identify the source if the patient is bleeding at 0.1ml/min or more. This scan involves removing and labeling some of the patient's own RBCs with technetium-99m, reinjecting them into the patient, and then scanning the abdomen for hot spots.[30, 31]

A retrospective study demonstrated that a repeat Meckel scan can be diagnostic in patients with an equivocal or negative finding who continue to have bleeding and a high clinical suspicion for Meckel diverticulum. Following an equivocal scan, 58% of the repeat scans were found to be positive, and 85% of these had a Meckel diverticulum. For patients with a negative first scan who remained with a high suspicion for Meckel diverticulum, 14% were positive on repeat study, and 86% remained negative. A repeat scan can also be helpful to differentiate a false-positive result from a true Meckel diverticulum.[32]

Selective arteriography may be helpful in patients in whom the results from scintigraphy and barium studies are negative. Usually, this occurs if the bleeding is either intermittent or has completely resolved.

When the rate of bleeding is greater than 1 mL/min, a superior mesenteric arteriogram can be helpful, but interpretation may be difficult due to overlying blood vessels. In these cases, selective catheterization of the distal ileal arteries may be needed.

Demonstration of abnormal arterial branches, dense capillary staining, or extravasation of the contrast medium confirms the presence of a Meckel diverticulum. However, a well-developed arterial supply may not always be present in the Meckel diverticulum; thus, these arteriographic signs are not very reliable.

Traditional small-bowel series using barium have been unreliable in the detection of Meckel diverticulum. However, in patients who require barium study to primarily look for other conditions, enteroclysis is more sensitive in detecting Meckel diverticulum. Enteroclysis involves using a continuous infusion of barium with adequate compression of the ileal loops and intermittent fluoroscopy to detect Meckel diverticulum. If the barium mixture is too dense and the fold pattern cannot be visualized, carboxymethylcellulose sodium can be used as the contrast medium. On barium studies, Meckel diverticulum may appear as a blind-ending pouch on the antimesenteric side of the distal ileum. If filling defects are visualized, the diverticulum may contain a tumor. Characteristic radiologic signs for Meckel diverticulum include demonstration of a triradiate fold pattern or a mucosal triangular plateau. Occasionally, a gastric rugal pattern may also be found within the Meckel diverticulum. A barium enema can be performed if intussusception is suspected. Some people have tried hydrostatic therapy to reduce intussusception, but this has not been found to be useful.

Previously, abdominal CT scanning was not considered helpful because differentiating Meckel diverticulum from the small-bowel loops is difficult. However, a blind-ending fluid-filled and/or gas-filled structure in continuity with small bowel may be visualized. CT scanning may also reveal an enterolith, intussusception, or diverticulitis. CT enterography advancements have increased the sensitivity in the diagnosis of Meckel diverticulum.[26]

A retrospective study was performed to determine the frequency of detecting symptomatic and asymptomatic Meckel diverticulum in patients known to have the lesion. A total of 85 CT examinations (23 on 14 symptomatic patients and 62 on 26 asymptomatic patients) were retrospectively reviewed after surgical resection of Meckel diverticulum. Among all 85 CT examinations, a Meckel diverticulum was detected in 34.1% of patients. In symptomatic patients, Meckel diverticulum could be seen in 57.1% on at least 1 CT examination and in 56.5% of total CT examinations. Among the 14 symptomatic patients with negative studies, 6 were children with little peritoneal fat, which likely related to the failure to see the diverticulum. In asymptomatic patients, Meckel diverticulum was detected in 42.3% patients on at least one CT examination and 25.8% of total CT examinations. The authors concluded that CT scan was able to detect Meckel diverticulum in 47.5% of all patients. The highest rates of success were found in symptomatic patients and in those with adequate peritoneal fat.[33]

Ultrasonography has been used in some cases of Meckel diverticulum. Ultrasonography tends to be helpful if the patient presents with anatomic rather than mucosal complications. A retrospective study analyzed ultrasound characteristics of pathologically proven Meckel diverticulum. The study concluded that Meckel diverticulum is difficult to detect by ultrasound (detection rate of 15.5%). However, the presence of complications such as intussusception (24%), intestinal obstruction (24%), and diverticulitis (15.5%) increased the rate of detection.[34]

Wireless capsule endoscopy has been successfully used to identify Meckel diverticulum in young children.[35]  In adults, this same technique has been used to identify an inverted Meckel diverticulum that presented as GI bleeding.[36]

Newer imaging modalities have been used to diagnose Meckel diverticulum. Magnetic resonance (MR) enterography was able to visualize a Meckel diverticulum in an adult who presented with GI bleeding after numerous other modalities had failed to reveal the source of bleeding. MRI of another case revealed a cystlike structure of the small intestine in the iliac fossa with high signal intensity. This cystlike structure had a tear drop shape in the non-enhanced T1-weighted spin-echo coronal image, suggesting that it was a blood-filled body. MRI can be used to detect inflamed Meckel diverticulum, especially attractive for pediatric patients due to lack of ionizing radiation.[37]

A multidetector-row CT (MDCT) was used to study a series of patients prior to surgery for small bowel obstruction. The images were retrospectively reviewed, and evaluated for visualization of Meckel diverticulum, complication type of Meckel diverticulum, location and grade of small bowel obstruction, and the identification of a normal appendix.[38]  The authors found that when the Meckel diverticulum is visualized on preoperative MDCT, it can be considered the likely source of the obstruction. If the obstructive process is seen in the midline location, at the terminal branch of SMA, then the Meckel diverticulum is possibly the cause of the obstruction. However, the preoperative diagnosis of Meckel cannot be made if it is not noted in MDCT. This is frequently the situation in children as the diverticulum is not as developed. Two children with obstruction, were noted to have congenital bands between the mesentery and Meckel diverticulum.[38]

Ambiguous results of a Meckel scan have recently been clarified with a hybrid single photon emission tomography/CT (SPECT/CT), enabling a direct correlation of anatomical and functional information. A child was diagnosed with Meckel diverticulum at age 3 years by planar scintigraphy; due to resolution of symptoms and concomitant congenital heart disease, surgery was not performed at the time. She presented 7 years later with massive hematochezia, and a repeat planar scintigraphy showed an uptake in the area of the kidney. Whether this was due to physiologic uptake by the kidney or by ectopic gastric mucosa is unclear. A SPECT/CT done was able to confirm that the Meckel diverticulum was the exact anatomic site of the focal concentration.[39]

Histologic Findings

In one study, heterotropic gastric mucosa was found in 62% of cases, pancreatic tissue was found in 6%, both pancreatic tissue and gastric mucosa were found in 5%, jejunal mucosa was found in 2%, Brunner tissue was found in 2%, and both gastric and duodenal mucosa were found in 2%.[2]

Although some reports have associated Helicobacter pylori with ectopic gastric mucosa in Meckel diverticulum, a small series of 21 consecutive patients from Turkey using polymerase chain reaction (PCR) failed to identify 23S ribosomal RNA sequences from the organism even in the 12 surgical specimens with heterotopic gastric mucosa.[40]

A retrospective case study showed Meckel diverticulum with gastric heterotopia has an increased frequency of abdominal pain, vomiting/nausea, and rectal bleeding compared with Meckel diverticulum with pancreatic heterotopia or no heterotrophic tissue.[41]

Carcinoid and gastrointestinal stromal tumors (GIST) have been found in resected specimen of perforated or symptomatic Meckel diverticulum. A case report described a case of perforated Meckel diverticulum in which histological findings revealed a GIST within the Meckel diverticulum. GISts can coexist along with other tumors. The study concluded that segmental resection of small bowel should be considered in cases of perforation due to chances of a tumor within the diverticulum.[42]

In another case report, an inverted Meckel diverticulum contained several aberrant smooth muscle bundles. They proposed that these muscle bundles may have produced abnormal peristaltic movement acting as a lead point for the inversion and ileoileal intussusception. [43]

Procedures

See Treatment for newer applications of advanced endoscopy for detecting and treating Meckel diverticulum.

 

Treatment

Medical Care

The emergency department evaluation and treatment of patients depends on the clinical presentation of Meckel diverticulum.

Because most symptomatic patients are acutely ill, establish an intravenous line immediately, start crystalloid fluids, and keep the patient on nothing by mouth (NPO) status. Obtain the blood investigations suggested above with a type and cross match. If significant bleeding occurs, perform a transfusion of packed red cells.

A patient who presents with intestinal obstruction usually requires nasogastric (NG) decompression. After passing the NG tube, perform plain radiography of the abdomen.

When a child presents with bleeding, specifically a dark tarry stool, perform a gastric lavage to rule out upper GI bleeding. If the gastric lavage is negative for bleeding, consider an upper endoscopy and flexible sigmoidoscopy.

Meckel scan results may be negative despite a high clinical suspicion of Meckel diverticulum. The surgery team should be consulted to discuss the possible need for laparoscopy and/or laparotomy, even without a nuclear medicine diagnosis.

Surgical Care

If the patient is bleeding but is hemodynamically stable, a Meckel scan is warranted. On the other hand, the presence of peritoneal signs or hemodynamic instability demands urgent surgical intervention. Signs of small bowel obstruction also require surgical intervention.[44]

A stationary foreign body within the right lower quadrant on imaging proximal to the ileocecal valve should raise suspicion for a Meckel diverticulum and prompt early surgical intervention. In a case report, a 6-year-old boy presented after having ingested a coin 2 days prior; serial abdominal radiographs demonstrated persistence of the coin in the right lower quadrant without a change in position over a 72-hour interval. The coin led to both obstruction and perforation of a Meckel diverticulum.[45]

Definitive treatment of a complication, such as a bleeding Meckel diverticulum, is the excision of the diverticulum along with the adjacent ileal segment. Excision is carried out by performing a wedge resection of adjacent ileum and anastomosis, with the use of a stapling device. Adjacent ileum is included in the resection because ulcers frequently develop in the adjacent part of the ileum.[46]  In those rare instances when the diverticulum is located on the mesenteric border, resection and anastomosis is preferred instead of a wedge resection.

Successful resection of a Meckel diverticulum, even in children and infants, can also be accomplished through laparoscopy, using an endoscopically designed autostapling device.[47, 48, 49] A large series of national trends in the surgical management of Meckel diverticulum found that one fourth of cases are now treated laparoscopically. This group was older (6.4 y ± 5.1 y vs 5.1 y ± 5.3 y) and had shorter length of stay and trended toward lower total hospital charges.[6]

In some cases of Meckel diverticulum, a primitive persistent right vitelline artery originating from the mesentery has been found during operation. When present, the artery is found to supply the Meckel diverticulum; therefore, it must be identified and ligated during the operation.

Diagnostic laparoscopy is now being used more commonly in cases where Meckel diverticulum is the cause of intestinal perforation, which is a less common presentation in young children. A case report described the use of laparoscopy in a neonate with pneumoperitoneum to diagnose and surgically resect the perforated Meckel diverticulum. Using a multiuse single-site port in the umbilicus potentially reduces the preoperative and postoperative phases, allowing for earlier resumption of enteral nutrition, which is beneficial outcome in newborns.[50]

A new technique using double-balloon enteroscopy (DBE) to diagnose a bleeding Meckel diverticulum and to assist in a minimally invasive standard surgical resection has been described. Previously, DBE has been used as a diagnostic tool followed by laparoscopic treatment of Meckel diverticulum. Twenty one patients with melena and or/maroon-colored stools had retrograde transanal DBE as the initial diagnostic method once they were stabilized. The enteroscope was passed from the cecum into the terminal ileum and then advanced until a lesion was identified. The light source was then manipulated to bring the lesion close to the umbilicus. An incision was made at the umbilicus. The diverticulum was then removed, resected, and, after an intestinal anastomosis, the bowel was placed back in abdominal cavity. This approach revealed Meckel diverticulum in 14 patient, who were all successfully treated. Five had a negative DBE study, and 2 had a lesion that prevented insertion of the enteroscope.

A clear advantage of this technique is direct visualization of the distal small bowel lumen permits easy identification of the bleeding source. Noninvasive diagnostic methods such as ultrasonography, scintigraphy, and CT scanning often yield false positive or false negative results, which may delay laparoscopy and treatment in pediatric patients. One potential significant limitation of this technique is that the upper small bowel is not examined. Thus, DBE should not be routinely used as the first investigation to diagnose gastrointestinal bleeding presenting with a large quantity of melena and/or maroon-colored stools.[51]

A study by Mizutani et al determined the specific characteristics of hemorrhagic Meckel diverticulum and incidental Meckel diverticulum at DBE.[52]  Findings during the procedure were classified into either major (ectopic gastric mucosa and/or open ulcer) or minor (ringlike scar). Hemorrhagic Meckel diverticulum correlated more with these findings. Specificity of major findings was 100%, and specificity of major and/or minor findings was 96%. This allowed identification of asymptomatic Meckel diverticulum, thus avoiding unnecessary laparotomy/laparoscopy and diverticulectomy. 

The most common postoperative complication after Meckel’s diverticulectomy is adhesive intestinal obstruction. This usually presents with gastrointestinal bleeding, and most commonly been reported in patients with an ischemic and congested intestine.[53]

Management of Meckel diverticulum in asymptomatic patients is controversial. In the past, if a Meckel diverticulum was encountered in a patient undergoing abdominal surgery for some other intra-abdominal condition, many surgeons recommended its removal.

This practice was questioned when a large series described an overall 4.2% likelihood of complications in Meckel diverticulum and a decreasing risk with increasing age. These authors concluded that assuming a 6% mortality rate from Meckel diverticulum complications, 400 asymptomatic diverticula would have to be excised to save one patient.[54]

Another faction favors prophylactic removal of a diverticulum, which is a simple operation. This view is supported by data that demonstrate that managing a complication of Meckel diverticulum is associated with high morbidity and mortality rates. Others feel the only exception to universal excision is if the diverticulum is so broad based or so short that stapled excision cannot be performed technically. Fortunately, patients are less likely to develop complications in both of these situations.

One small series suggested that only patients younger than 50 years clearly benefitted from removal if discovered unintentionally.[55]

Another study examined whether the appearance of the Meckel diverticulum was able to predict the need for resection based on the potential for complications. The patients were evaluated according to age, sex, clinical features, laboratory data, perioperative findings (diverticulum length, diameter, depth, thickening, height-to-diameter ratio [HDR]), pathology, and postoperative follow up.[56]  The authors found a correlation between the age of the patient and the size (length, diameter, and depth) of the Meckel diverticulum. With increasing age, Meckel diverticulum reaches larger sizes. The macroscopic appearance of the Meckel diverticulum did not predict the presence of heterotopic gastric mucosa and could not be used to guide subsequent surgery. Specifically, a thickened diverticulum had the same (68%) chance of containing heterotopic gastric mucosa as one without this finding (63%). The authors concluded regardless of appearance, Meckel diverticulum should be removed, except in certain situations unrelated to complications, such as peritonitis due to appendicitis or bowel perforation. The limitations of this study were that it had a small sample size (50 children) and that macroscopic thickening is a subjective criterion, which differs among clinicians. The study also found that resection of incidental Meckel diverticulum is not associated with higher operative morbidity or mortality than resection of symptomatic Meckel diverticulum, and thus all Meckel diverticulum should be removed.[56]

Consultations

Consultations with the following may be appropriate:

  • Radiologist

  • Surgeon

  • Gastroenterologist

 

Guidelines

Guidelines Summary

Although numerous retrospective studies have described trends in the diagnosis and treatment of Meckel Diverticulum, the amount of cases is insufficient to warrant official guidelines. 

 

Medication

Medication Summary

In addition to the definitive therapy, urgently administer a regimen of antibiotics (eg, ampicillin, gentamicin, and clindamycin or cefotetan) whenever acute Meckel diverticulitis, strangulation, perforation, or signs of small bowel obstruction or sepsis are present.

Antibiotics

Class Summary

Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the clinical setting.

Ampicillin (Omnipen, Marcillin)

Interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms.

Clindamycin (Cleocin, Cleocin Pediatric, ClindaMax Vaginal)

Useful treatment for serious skin and soft tissue infections caused by most staphylococci strains. Also effective against entericaerobic and anaerobic flora, except enterococci. Inhibits bacterial protein synthesis by inhibiting peptide chain initiation at the bacterial ribosome, where it preferentially binds to the 50S ribosomal subunit, causing bacterial replication inhibition.

Gentamicin (Gentacidin, Garamycin)

If used in combination with an antianaerobic agent, such as clindamycin or metronidazole, provides broad gram-negative and anaerobic coverage. Dosing regimens are numerous and adjusted on the basis of creatinine clearance and changes in distribution volume.

Cefotetan (Cefotan)

Second-generation cephalosporin used as single-drug therapy to provide broad gram-negative coverage and anaerobic coverage. Half-life is 3.5 h. Inhibits bacterial cell wall synthesis by binding to ≥ 1 of the penicillin-binding proteins; inhibits final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death.

Antibiotics have proven effective in decreasing rate of postoperative wound infection and improving outcome in patients with intraperitoneal infection and septicemia.

 

Follow-up

Complications

Because the diagnosis of Meckel diverticulum can be quite elusive, a high index of suspicion is warranted to correctly and expeditiously diagnose this condition. Complicated Meckel diverticulum can lead to significant morbidity and mortality, most often because of a delay in diagnosis. For example, a higher frequency of intestinal infarction has been encountered in patients who present with complete intestinal obstruction. Causes of mortality include strangulation, perforation, and exsanguination because of delay in resuscitation.

Once a complication arises and surgery is required, the operative mortality and morbidity rates have both been estimated at 12%. The cumulative long-term risk of postoperative complications in this cohort was found to be 7%. If the Meckel diverticulum is removed as an incidental finding, the risk of mortality and morbidity and long-term complications are much less (1%, 2%, and 2%, respectively).

A case study described a case of internal herniation and intestinal obstruction due to Meckel diverticulum. This rare presentation was due to internal herniation of bowel loops into a sac formed by mesentery of Meckel diverticulum and adhesion band.[57]

As many as 5% of complicated Meckel diverticulum contain malignant tissue.

Neuroendocrine tumors arising from Meckel diverticulum are very rare. A recent case report described Cushing syndrome due to ectopic adrenocorticotropic hormone (ACTH) secretion from a Meckel diverticulum. A somatostatin analogue scintigraphy was used to allow localization of the ectopic ACTH tumor source. Pathological analysis of the resected submucosal tumor of Meckel diverticulum confirmed a neuro-endocrine tumor with immunohistochemistry positive for ACTH. Surgical resection lead to complete resolution of symptoms.[58]