Meckel diverticulum is one of the most common congenital malformations of the gastrointestinal tract and occurs in the distal ileum. The majority of patients are asymptomatic, but symptoms may include rectal bleeding, abdominal pain, and vomiting. The diagnosis is made through imaging techniques, most commonly radionuclide scanning and surgical treatment is the method of choice for managing patients.
The majority of patients are asymptomatic and the diagnosis is often made incidentally. However, symptoms may be present, and most commonly include bleeding, abdominal pain, nausea, vomiting and cramping . Rectal bleeding is one of the most important signs and may range from minimal bleeding to significant hemorrhage that may lead the patient to anemia and possibly shock. Findings can include either fresh blood in stools or melena in some cases. Intestinal obstruction manifests with abdominal pain and constipation, while vomiting may also be reported. Inflammatory complications, such as acute diverticulitis, is of striking resemblance to appendicitis because symptoms that are reported include diarrhea, fever, abdominal pain and cramping, as well as tenderness in the periumbilical area. In very rare cases, an intestinal perforation may occur, leading to symptoms such as hypotension and severe pain. Because the clinical presentation of Meckel diverticulum includes nonspecific symptoms related to the gastrointestinal tract, a careful and detailed diagnostic workup should be conducted to identify this condition as the underlying cause, particularly in the pediatric population.
The diagnosis of Meckel diverticulum is often made after invasive surgical procedures are performed and presents a challenge for the physicians. History of rectal bleeding in the pediatric population should always include Meckel diverticulum in the differential diagnosis and the most common and most specific diagnostic method is radionuclide scanning with 99m technetium pertechnetate . This procedure has a very high diagnostic accuracy because the radioactive isotope binds to ectopic sites of gastric mucosa, most commonly in the Meckel diverticulum. Alternative methods include computed tomography (CT scan) with oral contrast since plain CT does not show hollow organs on regular scans. CT scans may reveal intussusception, volvulus, or neoplasms , but in the majority of cases, surgical exploration and laparoscopy are techniques that provide a definite diagnosis. Since the symptomatology is quite similar to acute appendicitis, explorative surgery is commonly performed. Additional diagnostic methods include abdominal X-rays, barium enema, and angiography.
In virtually all cases, surgical resection is the method of choice. Surgical procedures include diverticulectomy or bowel resection with anastomosis if the intestinal perforation is observed.
Because surgery is the main treatment strategy, its use in asymptomatic patients has been discussed extensively. Because the diverticulum can cause complications, prophylactic surgery has been established as a beneficial method of treatment  , especially in male patients, in whom complications are much more common .The symptomatic patients are always treated surgically.
In the case when diverticulitis is present, antibiotic therapy may be indicated. Agents of choice include trimethoprim-sulfamethoxazole double-strength tablet q12h or ciprofloxacin 750 mg q24h, or levofloxacin 750 mg q24h combined with metronidazole 500 mg q6h . All of these drugs are taken orally, and the duration of therapy is usually 7-10 days. Alternatives include moxifloxacin and amoxicillin-clavulanic acid, while patients with more severe diverticulitis may receive piperacillin-tazobactam, ertapenem or imipenem intravenously.
The prognosis for patients with Meckel diverticulum is generally good, as this congenital intestinal abnormality is often diagnosed incidentally, while a minority of patients develop symptoms. Both preoperative and postoperative complications may occur, most commonly development of adhesions that can cause bowel obstruction , but various malignant tumors have been identified in these patients, including carcinoid tumor, pancreatic adenomas, sarcoma and other. Fortunately, they are rare and occur in less than 5% of patients.
Meckel diverticulum develops during the early fetal development, as the foregut remains connected with the yolk sac through the vitelline or omphalomesenteric duct. Normally, the connection between the two structures is achieved during the 3rd week of gestation and is terminated between the 7th and the 9th week. But for unknown reasons, the connection persists and leads to the development of a true diverticulum . True diverticulum implies that all layers of the intestinal wall are present, while ectopic mucosal cells may be present, such as gastric parietal cells that secrete hydrochloric acid.
Meckel diverticulum is estimated to be the most common congenital intestinal malformation, being present in 1-3% of the population . The majority of patients are asymptomatic through life, and 4-6% of patients develop symptoms, which is usually during childhood, but symptoms may occur at any age . Although gender predilection has not been established, various studies indicate that male patients are much more prone to developing complications. No known risk factors are established so far.
During early fetal life, the foregut and the yolk sac become connected via the vitelline duct at the 3 rd week of gestation. For reasons that are still not understood, the vitelline duct does not close during the 8th week of gestation when it should, which results in permanent connection of the yolk sac and the foregut. Eventually, the part of the sac that is connected transforms into intestinal tissue, with all cellular layers - a true diverticulum. In addition to intestinal cells, the heterotropic mucosa may be present , most commonly gastric parietal cells. Pancreatic, duodenal, endometrial mucosa have been described in the diverticulum as well. It is established that the secretion of acid leads to intestinal injury, which is assumed to be responsible for intestinal bleeding, which is one of the most common manifestations of this syndrome, but for other symptoms as well .
Intestinal obstruction commonly occurs in patients with Meckel diverticulum, mainly due to intussusception, but other mechanisms are described as well, including hernial incarceration (also known as Littre's hernia), volvulus, and tumors in rare cases.
Meckel diverticulum may also result in the development of acute diverticulitis, which may lead to abscess formation and significant inflammatory changes and it is seen predominantly in younger patients.
The majority of patients with Meckel diverticulum are asymptomatic and the diagnosis is often incidental. Preventive measures should be oriented toward identifying the presence of this congenital anomaly while it does not cause any symptoms and treat accordingly. Although lifetime complications and risk of developing symptoms are small, prophylactic surgical resection is recommended by the majority of studies, for the reason of preventing potential complications.
Meckel diverticulum is estimated to be prevalent in up to 3% of the population, making this congenital malformation of the intestine the most common gastrointestinal anomaly around the world. It has been described more than 200 years ago , and the cause is the incomplete closure of the vitelline duct that connects the foregut and the yolk sac during early fetal life. As a result, the part of the yolk sac becomes intestinal tissue with all mucosal and submucosal layers, which illustrates that this is a "true" diverticulum . In addition, it may contain heterotrophic cells, most commonly the parietal cells of the gastric mucosa, which secrete hydrochloric acid and damage the surrounding intestinal mucosa, thus producing intestinal injury. This syndrome equally affects both genders, but for unknown reasons, complications are more frequently observed among males. Characteristic symptoms of rectal bleeding and abdominal pain are most commonly reported. Although the majority of patients are asymptomatic and less than 10% of patients exhibit symptoms. Complications are rare and may include intestinal perforation, severe obstruction, acute diverticulitis, and development of tumors, which is why it is very important to establish the diagnosis in its asymptomatic stages. Imaging techniques are initial diagnostic methods, and the most commonly used is radionuclide scanning with technetium 99m pertechnetate scan, which comprises isotope binding to the ectopic gastric mucosa. However, because acute symptoms of the abdomen indicate exploratory surgery, this method usually confirms the diagnosis. Treatment includes diverticulectomy, and in cases of intestinal perforation, bowel resection, and anastomosis. Surgery is indicated in both symptomatic and asymptomatic patients, primarily to reduce the risk of developing further complications.
Meckel diverticulum is a malformation of the intestine that occurs during early fetal life, and it is the most common congenital intestinal anomaly encountered in medical practice. It is present in approximately 2-3% of the population, and the majority of patients are asymptomatic. During early development of the fetus, the yolk sac is connected with the foregut through a duct during the 3rd week of life, and this connection should be terminated around the 8th week. However, for unknown reasons, this connection persists, and the part of the yolk sac together with the vitelline duct is transformed into intestinal tissue, known as Meckel diverticulum. This disorder is equally diagnosed in both genders, but for some reason, male patients much more commonly develop complications. The diagnosis is often made incidentally because it rarely causes complaints, but symptoms that occur in patients are a consequence of intestinal injury in this segment. Injury occurs because cells of the gastric mucosa may be present in the diverticulum, and acid production leads to the damage. Symptoms that are most commonly reported include rectal bleeding, abdominal pain, cramping, nausea, vomiting, and fever. The diagnosis can be made using imaging studies, most notably through the use of a radionuclide scan (known as the technetium 99m pertechnetate scan). The principle includes the introduction of an isotope that will bind to the cells of the gastric mucosa outside the stomach and can identify their presence in the diverticulum. However, the clinical presentation can be strikingly similar to appendicitis, and because significant complications, such as intestinal perforation and severe bleeding may occur, surgery is often the main diagnostic method, but it is also the principal form of treatment. The diverticulum is often removed, or if severe damage to the segments of the intestine that are close, a bowel resection may be performed. Patients with Meckel diverticulum have a good prognosis, the majority of patients do not develop any complications during their lifetime. However, in some patients, intestinal perforation, and severe bleeding may occur and pose significant risks, which is why a diagnosis of this congenital anomaly almost always indicates surgery.