Practice Essentials
Gastrointestinal (GI) duplications are rare congenital malformations that may vary greatly in presentation, size, location, and symptoms. [1, 2]
In 1733, Calder published the first report of an intestinal duplication. In 1937, Ladd introduced the term duplication of the alimentary tract. This condition consists of a group of congenital anomalies with the following three characteristics:
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A well-developed coat of smooth muscle is present
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The epithelial lining represents some portion of the alimentary tract
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Duplications are frequently intimately attached to some portion of the GI tract
Alimentary tract duplications are uncommon and may present as solid or cystic tumors, intussusception, perforation, or GI bleeding. A high index of suspicion is required in such cases. Appropriate investigations, including imaging techniques, should be directed toward adequate and planned surgery.
Surgical resection is the preferred method of treatment for most GI duplications; however, for duodenal duplications, surgical resection is inadvisable because of the close proximity of these duplications to the biliary and pancreatic ductal system. Surgical management depends on the location, size, and shape of the duplication. Controversies and future management strategies are related to management of duplications, as well as the associated anomalies.
For patient education resources, see the Procedures Center, as well as Gastrointestinal Endoscopy.
Anatomy
GI duplications may be divided into the following types:
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Cervical duplications
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Thoracic and thoracoabdominal duplications
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Gastric duplications
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Duodenal duplications
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Other small-intestine duplications
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Colonic duplications
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Rectal duplications
Cervical duplications are generally duplications of the esophagus. Most esophageal duplications involve the distal esophagus. [3]
In as many as one third of thoracic and thoracoabdominal duplications, there is a second or third duplication cyst below the diaphragm; therefore, computed tomography (CT) should include the abdomen. Almost all patients with thoracic or thoracoabdominal duplications have vertebral anomalies, and the central nervous system (CNS) may be involved. The histologic similarity and anatomic proximity of bronchogenic cysts and intramural esophageal duplications support their common origin. [4]
Gastric duplications are generally cystic. They are generally located on the greater curvature and have no communication to the stomach.
Duodenal duplications generally do not communicate with the intestinal lumen. They can arise from the bile ducts or the pancreas.
Most small-intestine duplications are located in the ileum. Duplications may be cystic or tubular and are located on the mesenteric border, often sharing a common muscular wall and blood supply with the native intestine. Multiple small-intestine duplications may be present. [5]
Cystic colonic duplications may be isolated or may have an external fistula to the skin, urinary tract, or normal colon. Tubular colonic duplications can also occur with duplication or triplication of the colon. Tubular duplication of the colon is often associated with duplication of the anus, vagina, and penis. Multiple short-segment duplications of the colon may also be present. [6]
Rectal duplications occur in the retrorectal space.
Associated anomalies are common with certain duplications, and screening for these anomalies should be performed in appropriate patients. The following are examples:
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Thoracoabdominal duplications - Vertebral anomalies (approximately 75%)
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Enteric cystic duplications - Intestinal atresias
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Tubular hindgut duplications - Genitourinary malformations
Pathophysiology
GI duplications are most frequently single, tubular, or cystic and are most often located on the mesenteric side of the native alimentary tract structure. [7] Symptoms are often related to the location of the duplication; oral and esophageal lesions can create respiratory difficulties, whereas lower GI lesions may cause nausea, vomiting, [5] bleeding, perforation, or obstruction. [8]
Patients with cervical esophageal duplications or thoracic/thoracoabdominal duplications may present with respiratory distress that is caused by compression of the airway; this can be life-threatening.
The presence of heterotopic mucosa (eg, gastric mucosa) in a duplication can lead to peptic ulcerations, bleeding, and perforation with peritonitis.
Neoplastic changes have been reported in GI duplications.
Etiology
The true etiology of GI tract duplications is not known. [9] Several theories have been postulated.
The idea that the initial developmental abnormality occurs in the gastrulation stage and results in a split notochord has been proposed. During early embryogenesis, the notochord is open, and the endoderm of the yolk sac and the ectoderm of the notochord are fused; a tube called the neuroenteric canal connects the yolk sac and the amnion.
As part of the development of the split notochord, an endodermal-ectodermal adhesion between the cord has been proposed to result in the persistence of an endomesenchymal tract between the yolk sac and the amnion. The endomesenchymal tract formed is responsible for the anomalies of the entire GI system. However, not all duplications are compatible with this theory, and other etiologies have been proposed.
Some duplications of the foregut and hindgut may result from "partial twinning." These duplications may be associated with other paired structures, such as those found in the genital and urinary tract. Other duplications, especially those of the ileum, may occur as a result of persistent embryologic diverticula. Some portions of the intestinal tract have a solid stage during development; therefore, duplications of these structures may result from "aberrant luminal recanalization." Finally, intrauterine environmental factors, such as trauma or hypoxia during a vascular accident, may cause duplications at any level of the GI tract.
Epidemiology
GI duplications are observed in 1 of every 4500 autopsies, predominantly in white males. Synchronous GI duplications occur in as many as 15% of patients. Relative frequencies of the various types are as follows:
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Cervical duplications - Cervical esophageal duplication cysts are the most unusual GI duplication, with fewer than 20 cases reported
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Thoracic and thoracoabdominal duplications - These make up 4% of all GI duplications
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Gastric duplications - These account for 7% of all GI duplications
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Pyloric duplications - These are extremely rare; however, they are reported in the literature [10]
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Duodenal duplications - These account for 5% of all GI duplications
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Small-intestine duplications - The small intestine is the most frequent site of GI duplications, accounting for 44% of cases [5]
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Colonic duplications - These may be cystic or tubular; they represent 15% percent of duplications
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Rectal duplications - These represent up to 5% of GI duplications [11]
In a single-institution review of GI duplications in 72 children, Xiang et al found the ileocecal area to be the site most commonly involved, followed by the colon, jejunum, stomach, and duodenum. [12]
Prognosis
The outcome of surgical (or medical) management of GI duplications is favorable. Metaplastic changes that have been reported in untreated GI duplications can be prevented, depending on the location of the duplication, by appropriate surgical intervention.
The severity and types of malformations associated with GI duplications play a significant role in determining morbidity and mortality.
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Jejunal duplication in a newborn. Intraoperative image demonstrates a cystic structure found on the antimesenterial side of the jejunum. A segmental resection was performed and the jejunum anastomosed.
