Illustration with most common locations of alimentary duplications . From Puri P, Mortell A. Duplications of the Alimentary Tract. In: Pediatric Surgery: Diagnosis and Management. Puri P, Hollwarth ME, eds. New York: Springer, 2009. 423–434. Reprinted with permission.
Jejunum/ileum 50 %
Esophagus 19 %
Stomach 9 %
Colonic 7 %,
Rectum 5 %,
Duodenal 4 %,
Thoracoabdominal 4 %,
The underlying pathophysiology is unknown, and theories as to the development of duplication cysts are varied. These include formation as a result of persistent embryonic diverticulum, a defect in recanalization, partial twinning, or secondary to a split notochord and fetal hypoxia [1, 2, 8]. Importantly, intestinal duplications share the muscular wall and blood supply with the adjacent intestine and, therefore, often reside within the leaves of mesentery . The lining of the duplication is often the same as the adjacent native tissue, but it can also have ectopic mucosa. The most common ectopic tissue found is gastric tissue, but there have been documented cases of exocrine and endocrine pancreatic tissue. Ectopic tissue is more commonly found in cystic duplications than tubular duplications [1, 2, 8].
Ectopic gastric tissue can cause symptoms when the local anatomy is not able to handle the produced acid, which can result in bleeding or perforation. Infections of a duplication cyst can cause rapid enlargement, with complications including airway compromise or even meningitis in cases where there is a connection with the CNS.
The history and clinical presentation is dependent upon the size, location, and tissue content of the duplication. Patients can present with obstructive symptoms, respiratory compromise, an asymptomatic but palpable mass, or with intussusception, bleeding, or perforation with peritonitis.
Esophageal: can present with dysphagia or respiratory symptoms. Lesions are usually cystic and located in the posterior mediastinum.
Gastric: can present with symptoms of peptic ulcer disease, if the cyst communicates with stomach.
Duodenal: may present with jaundice, if obstructive.
Intestinal: often present with symptoms of small bowel obstruction or intussusception.
Colonic: can present with vague abdominal pain.
Rectal: often present with a fistula or perineal mucosal swelling.
Like clinical presentation, physical exam is dependent upon the location and clinical presentation of the duplication.
Basic preoperative labs are recommended prior to surgery, including a complete blood count and a comprehensive metabolic panel.
Gold standard initial imaging for a cystic intestinal duplication is an abdominal ultrasound. Ultrasound will show an inner hyperechoic rim of mucosa–submucosa and an outer hypoechoic muscular layer.
For suspected tubular duplications, a contrast enhanced CT scan is recommended to evaluate the extent of the duplication.
A Technetium scan is recommended for tubular structures not amenable to resection for evaluation of ectopic gastric tissue.
For thoracoabominal cases, a preoperative MRI is recommended to evaluate for vertebral abnormalities and to exclude a communication with spinal structures.
For esophageal duplications, it is recommended to place the patient in the lateral decubitus position with the affected side facing upward . Often, cysts are more posterior than lateral, thus the patient is almost prone. For lesions in the right upper quadrant, it is recommend the patient lies in the supine position, at the end of the bed (frog-legged if patient is small, stirrups if they are larger) with the surgeon positioned between the legs [3, 8]. For pelvic/rectal lesions, consideration should be given to positioning the patient at the end of the bed, with the surgeon standing above the patient’s head (or to the patient’s left side), so the target area is as shown in Fig. 27.2 . The rectum may need to be irrigated with betadine if a combined transanal procedure is being considered.
Depiction of general laparoscopic technique, taken from SAGES manual . From Meehan J. Pediatric Minimally Invasive Surgery: General Considerations. In: The SAGES Manual: Basic Laparoscopy and Endoscopy. 3rd edition. Soper N, Scott-Connor CEH, eds. New York: Springer, 2012. 443–447. Reprinted with permission.
Rarely, the cyst can be enucleated and does not require a segmental resection. If no segmental resection is required, then all ports can be 3–5 mm. If segmental resection is required, then a 10 or 12 mm port may need to be used (typically as a camera port initially) to insert a stapler or exteriorize the bowel. Common instruments used include hook cautery, an energy device such as harmonic scalpel or Ligasure, blunt bowel graspers, and Maryland dissector. A newly developed 5 mm laparoscopic stapler may have some utility in these cases for smaller pediatric patients.