Meckel Diverticulum in Children
Meckel Diverticulum in Children
Meckel diverticulum is the most common congenital anomaly of the gastrointestinal tract, affecting approximately 2% of the population. It is a true diverticulum, containing all layers of the intestinal wall, and is a remnant of the omphalomesenteric duct.
Key Points:
- Often described by the "rule of 2s":
- Occurs in about 2% of the population
- Located within 2 feet of the ileocecal valve
- Often 2 inches in length
- Commonly presents before age 2
- Male to female ratio is 2:1
- Most cases are asymptomatic and discovered incidentally
- When symptomatic, it often presents with gastrointestinal bleeding, intestinal obstruction, or diverticulitis
- Treatment is typically surgical for symptomatic cases
Embryology and Pathophysiology
Meckel diverticulum results from incomplete obliteration of the omphalomesenteric (vitelline) duct during fetal development:
- The omphalomesenteric duct normally connects the midgut to the yolk sac during early fetal development
- It usually obliterates completely by the 7th week of gestation
- Failure of complete obliteration results in Meckel diverticulum
Histological Features:
- Contains all layers of the normal intestinal wall
- Often contains heterotopic tissue:
- Gastric mucosa (present in about 50% of cases)
- Pancreatic tissue (present in about 5% of cases)
- Rarely, colonic or duodenal mucosa
The presence of heterotopic gastric mucosa is clinically significant as it can secrete acid, leading to ulceration and bleeding.
Clinical Presentation
The majority of Meckel diverticula are asymptomatic. When symptomatic, the presentation can vary:
Gastrointestinal Bleeding:
- Most common symptomatic presentation in children
- Usually painless and may be massive
- Typically presents as maroon-colored or bright red stools
- Often due to ulceration from acid secretion by heterotopic gastric mucosa
Intestinal Obstruction:
- Second most common presentation
- May occur due to:
- Intussusception with the diverticulum as the lead point
- Volvulus around a fibrous band connecting the diverticulum to the umbilicus
- Internal hernia
- Presents with abdominal pain, vomiting, and constipation
Diverticulitis:
- Can mimic acute appendicitis
- Presents with right lower quadrant pain, fever, and vomiting
Other Presentations:
- Umbilical discharge (if patent omphalomesenteric duct persists)
- Perforation
- Rarely, neoplasms arising within the diverticulum
Diagnosis
Diagnosing Meckel diverticulum can be challenging due to its varied presentation. The following diagnostic approaches are often used:
Laboratory Studies:
- Complete blood count: May show anemia in cases of chronic bleeding
- Stool guaiac test: To detect occult blood
Imaging Studies:
- Technetium-99m pertechnetate scan (Meckel scan):
- Most sensitive and specific test for detecting Meckel diverticulum
- Detects heterotopic gastric mucosa
- Sensitivity of 85-90% in children
- Ultrasonography: May visualize the diverticulum or complications like intussusception
- CT scan: Can be helpful in cases of obstruction or inflammation
- Wireless capsule endoscopy: May be useful in cases of obscure gastrointestinal bleeding
Other Diagnostic Procedures:
- Double-balloon enteroscopy: Can directly visualize the diverticulum
- Laparoscopy: Both diagnostic and therapeutic
Differential diagnosis may include:
- Acute appendicitis
- Intussusception
- Inflammatory bowel disease
- Other causes of gastrointestinal bleeding (e.g., peptic ulcer disease, arteriovenous malformations)
Treatment
The management of Meckel diverticulum depends on whether it is symptomatic or asymptomatic:
Symptomatic Meckel Diverticulum:
- Surgical resection is the treatment of choice
- Diverticulectomy: Simple excision of the diverticulum
- Segmental resection: Removal of a segment of ileum containing the diverticulum
- Can be performed open or laparoscopically
- Any fibrous bands connecting to the umbilicus should be divided
Asymptomatic Meckel Diverticulum:
- Management is controversial
- Some surgeons advocate for prophylactic resection, especially in:
- Males (higher risk of becoming symptomatic)
- Patients younger than 50 years
- Diverticula with suspicious features (e.g., longer than 2 cm)
- Others recommend leaving asymptomatic diverticula in place due to low lifetime risk of complications
Preoperative Management:
- Fluid resuscitation and correction of electrolyte imbalances
- Blood transfusion if significant bleeding has occurred
- Antibiotic prophylaxis
Postoperative Care:
- Monitoring for postoperative complications
- Gradual reintroduction of oral intake
- Pain management
Complications
While many Meckel diverticula remain asymptomatic, potential complications include:
- Gastrointestinal bleeding: Can be life-threatening if massive
- Intestinal obstruction: May lead to bowel ischemia if not promptly addressed
- Diverticulitis: Can progress to perforation if left untreated
- Perforation: Can result in peritonitis
- Neoplasms: Rarely, tumors can develop within the diverticulum
Postoperative Complications:
- Wound infection
- Intra-abdominal abscess
- Anastomotic leak (if segmental resection was performed)
- Adhesive small bowel obstruction
Long-term prognosis after surgical treatment is generally excellent, with most patients experiencing complete resolution of symptoms and no recurrence.
Meckel Diverticulum in Children
- QUESTION: What is Meckel diverticulum?
ANSWER: Meckel diverticulum is a congenital anomaly of the small intestine, specifically a remnant of the omphalomesenteric duct, typically located on the antimesenteric border of the ileum. - QUESTION: What is the "rule of 2s" associated with Meckel diverticulum?
ANSWER: The "rule of 2s" states that Meckel diverticulum occurs in about 2% of the population, is often 2 inches long, is typically found within 2 feet of the ileocecal valve, often presents before age 2, and is 2 times more common in males. - QUESTION: What types of ectopic tissue are commonly found in Meckel diverticulum?
ANSWER: The most common ectopic tissues found in Meckel diverticulum are gastric mucosa (present in about 50% of cases) and pancreatic tissue (present in about 5% of cases). - QUESTION: What is the most common complication of Meckel diverticulum in children?
ANSWER: The most common complication of Meckel diverticulum in children is gastrointestinal bleeding, typically due to ulceration of the ileal mucosa adjacent to ectopic gastric tissue. - QUESTION: How does Meckel diverticulum typically present in young children?
ANSWER: In young children, Meckel diverticulum often presents with painless rectal bleeding, which may be bright red or maroon in color. - QUESTION: What other complications can arise from Meckel diverticulum?
ANSWER: Other complications include intestinal obstruction (due to intussusception or volvulus), diverticulitis, and perforation. - QUESTION: How is Meckel diverticulum diagnosed?
ANSWER: Diagnosis often involves technetium-99m pertechnetate scintigraphy (Meckel scan), which can detect ectopic gastric mucosa. Other methods include ultrasound, CT scan, and sometimes exploratory laparoscopy or laparotomy. - QUESTION: What is the sensitivity of the Meckel scan in diagnosing Meckel diverticulum?
ANSWER: The sensitivity of the Meckel scan is approximately 85-90% in children, but it can be lower in adults or if there is no ectopic gastric mucosa present. - QUESTION: How does the presentation of Meckel diverticulum differ in older children and adults?
ANSWER: In older children and adults, Meckel diverticulum is more likely to present with symptoms of intestinal obstruction or inflammation (diverticulitis) rather than bleeding. - QUESTION: What is the standard treatment for symptomatic Meckel diverticulum?
ANSWER: The standard treatment for symptomatic Meckel diverticulum is surgical resection, typically involving removal of the diverticulum and a small segment of adjacent ileum. - QUESTION: Should asymptomatic Meckel diverticulum be removed if found incidentally?
ANSWER: The management of incidentally discovered, asymptomatic Meckel diverticulum is controversial. Factors such as age, diverticulum length, and presence of ectopic tissue may influence the decision to remove it prophylactically. - QUESTION: How does Meckel diverticulum relate to umbilical abnormalities?
ANSWER: Meckel diverticulum can sometimes be associated with a patent omphalomesenteric duct, which can result in an umbilical fistula or sinus. - QUESTION: What is the role of laparoscopy in managing Meckel diverticulum?
ANSWER: Laparoscopy can be used for both diagnosis and treatment of Meckel diverticulum, offering a minimally invasive approach for resection in many cases. - QUESTION: How does Meckel diverticulum affect intestinal motility?
ANSWER: Meckel diverticulum itself doesn't typically affect intestinal motility unless it leads to complications like obstruction or intussusception. - QUESTION: What is the long-term prognosis for children who have had a Meckel diverticulum resected?
ANSWER: The long-term prognosis is generally excellent after resection of a symptomatic Meckel diverticulum, with most children experiencing no further related problems. - QUESTION: How does Meckel diverticulum differ from other types of small bowel diverticula?
ANSWER: Meckel diverticulum is a true diverticulum, containing all layers of the intestinal wall, whereas most other small bowel diverticula are acquired and false (lacking the muscular layer). - QUESTION: What is the significance of Meckel diverticulum in neonates?
ANSWER: In neonates, Meckel diverticulum can be associated with other congenital anomalies and may present as an omphalomesenteric duct remnant causing umbilical drainage. - QUESTION: How does Meckel diverticulum affect nutrient absorption?
ANSWER: Meckel diverticulum typically doesn't affect nutrient absorption unless it leads to complications like chronic inflammation or significant bleeding. - QUESTION: What is the role of capsule endoscopy in diagnosing Meckel diverticulum?
ANSWER: While not typically the first-line diagnostic tool, capsule endoscopy can sometimes identify Meckel diverticulum, particularly in cases of obscure gastrointestinal bleeding. - QUESTION: How does the presence of ectopic pancreatic tissue in Meckel diverticulum affect its presentation?
ANSWER: Ectopic pancreatic tissue in Meckel diverticulum can lead to symptoms mimicking pancreatitis or may cause intestinal obstruction due to inflammation or mass effect. - QUESTION: What is the relationship between Meckel diverticulum and Crohn's disease?
ANSWER: Meckel diverticulum can be involved in Crohn's disease, potentially leading to misdiagnosis or complications. Some studies suggest a higher incidence of Meckel diverticulum in patients with Crohn's disease. - QUESTION: How does Meckel diverticulum affect growth and development in children?
ANSWER: Meckel diverticulum typically doesn't affect growth and development unless it causes chronic blood loss leading to iron deficiency anemia, or if it results in chronic inflammation or malabsorption. - QUESTION: What is the role of H2 blockers or proton pump inhibitors in managing Meckel diverticulum?
ANSWER: H2 blockers or proton pump inhibitors may be used temporarily to reduce acid secretion from ectopic gastric mucosa, potentially helping to control bleeding while awaiting definitive treatment. - QUESTION: How does Meckel diverticulum affect the immune function of the intestine?
ANSWER: Meckel diverticulum itself doesn't typically affect intestinal immune function, but if it becomes inflamed or ulcerated, it can lead to local immune activation and inflammation. - QUESTION: What is the significance of a negative Meckel scan in a child with suspected Meckel diverticulum?
ANSWER: A negative Meckel scan doesn't definitively rule out Meckel diverticulum, as it may miss cases without ectopic gastric mucosa or with insufficient uptake. Further investigation may be warranted if clinical suspicion remains high. - QUESTION: How does Meckel diverticulum affect pregnancy and childbirth in females?
ANSWER: While usually asymptomatic, Meckel diverticulum can rarely cause complications during pregnancy or childbirth, such as obstruction or perforation, due to changes in abdominal pressure and intestinal displacement. - QUESTION: What is the role of genetic factors in the development of Meckel diverticulum?
ANSWER: While Meckel diverticulum is generally considered a sporadic condition, some studies suggest a possible genetic component, with a higher incidence observed in certain families and in patients with specific genetic syndromes. - QUESTION: How does the management of Meckel diverticulum differ in premature infants?
ANSWER: In premature infants, the management of Meckel diverticulum may be more conservative due to increased surgical risks. Close monitoring and medical management may be preferred unless complications arise.
