Intestinal Duplications (also called Intestinal Tract Duplications, duplication cysts, foregut duplications, esophageal duplications, others)

Definition: An abnormal portion of intestine which is attached to or intrinsic with the normal bowel. The cyst or duplicated bowel is typically lined with intestinal mucosa, but heterotopic (tissue from other areas of the body) may be found within it.

History
1930s the term “duplication” was popularized by William Ladd.

Embryology
Multiple theories exist. No one theory can explain all types and their associated anomalies. Bentley proposed the “Split notochord theory” an embryologic error may result in abnormal diverticularization of the GI endoderm through the developing notochord during the fourth week of gestation

Location and Appearance
Located throughout the entire gastrointestinal tract. Duplications may vary widely in size and length. They may be spherical or tubular in appearance. The duplications must posses a well-developed layer of smooth muscle and a mucous membrane lining derived from some part of the GI tract.

Epidemiology
Exact incidence is unknown. Approximately two-thirds of all intestinal duplications are discovered within the first two years of life. One-third identified in the newborn period. 1961 Potter reported 2 cases in more than 9000 fetal and neonatal autopsies.

Clinical Presentation
Many are diagnosed incidentally or on prenatal ultrasound.
Symptoms
– Pain
– Obstructive Symptoms
– GI Bleeding
Symptoms may be the direct effect of distention of the duplication or result from compression of adjacent organs. Abrupt hemorrhage with hemodynamic instability may result from a cyst lined with gastric mucosa that ulcerates and eventually erodes into adjacent organs and/or vessels.

Radiographic Imaging
X-ray’s are generally nonspecific in intestinal duplication unless obstruction is seen. Ultrasound may often detect cystic duplications. CT scan may also be useful in identifying alimentary tract duplications, but may miss the lesion if the duplicated bowel is not distended. MRI may be necessary if neurologic symptoms of spinal cord compression exist and with evidence of bony spinal abnormalities on plain film or CT scan. Esophagram may show an extrinsic mass effect on the esophagus. Ultrasonography or CT may also be used as a screening tool to address the 10-20% incidence of multiple lesions. Prenatal ultrasonography is also identifying a large number of duplications. Non-cystic duplications may be missed by all modality. Meckel’s scanning may be helpful in bleeding duplications with ectopic mucosa.

Locations
-Oral and lingual
-Esophageal
-Thoracoabdominal
-Gastric
-Duodenal
-Small Bowel
-Colonic
-Rectal

Oral and Lingual

Oral and lingual duplications represent 1% of duplications. Often present as an asymptomatic mass in the oral region. They may contain ectopic gastric mucosa. Presence of an oral cyst or mass lesion is an indication for excision. Treatment of oral duplications
is excision with closure of remaining mucosa.

Esophageal duplications

Esophageal duplications make up 20% of all duplications
– 23% or in the cervical (neck) esophagus, 17% are in the middle esophagus and 40% are in the distal, also intraabdominal esophagus, spanning multiple areas.

Presentation
– Asymptomatic neck mass
– Upper airway obstruction
– Dysphagia

Differential Diagnosis
Cystic hygroma
Thyroglossal duct cyst
Branchial cleft cyst
Solid tumors

Diagnosis
CXR as a posterior mediastinal mass
CT scan (Better detail of lesion)
Esophagram may allow identify lesion or aid in evaluation of esophageal connection

Treatment is resection (removal)
– Thoracotomy or thoracoscopy
– Usually separates from esophagus
– Rarely will require repair of esophagus or esophagectomy

Complications if not treated
– Bleeding
– Perforation
– Airway compromise

Thoracoabdominal Duplications
-Represents 5% of all duplications.

These often presentation with respiratory distress, vomiting, GI bleeding, or occasionally meningitis. There is a high association of vertebral anomalies and neuroenteric connections.

Thoracic component
– Retropleural
– May extend to neck

Abdominal component
– May connect to stomach, pylorus, duodenum, pancreas, jejunum or ileum

Treatment
– Thoracotomy and laparotomy with resection
– Thoracoscopic and laparoscopic resection
– Joining of duplication and native intestine without resection
– Spinal component must be considered when planning resection

Complications
– Incomplete resection with recurrent cysts, meningitis, hemothorax and enteric fistulas. Leakage from anastomosis or staple lines.

Gastric Duplications
-Approximately 7% of total

Location of gastric duplications
67%greater curvature
8%-lesser curvature
4%-anterior wall
10%-posterior wall
2%-pylorus

Presenting symptoms of gastric duplications
Commonly presents in first year of life
More common in girls (2:1)
Nonbilious vomiting
GI bleeding
Perforation
Fistula to spleen or lung
Palpable abdominal mass

Differential Diagnosis
– Pancreatic pseudocyst
– other intestinal duplications
– Pyloric stenosis

Treatment is surgical
– Excision of cyst with part of common wall and closure of serosal defect
– Untreated gastric cysts may undergo malignant degeneration
– May be associated with pancreatitis (Nearly 100% of these have a connection to the normal pancreatic duct of Wirsung or an aberrant pancreatic lobe. ERCP may be helpful)

Duodenal Duplications
3% of all intestinal duplications
Occur in the first and second portions of duodenum
Commonly cystic (does not connect to duodenum)
May contain duodenal or gastric mucosa

Presentation
– Vomiting
– GI bleeding
– Palpable mass
– Obstructive jaundice
– ERCP may be helpful adjunct in diagnosis

Treatment
– Resection
– Trans-duodenal window between duodenum and cyst thereby opening of the cyst into the GI tract
– Care must be taken to avoid common bile duct
– Drainage with Roux-en-Y cysto-jejunostomy has been reported for cysts intimately associated with biliary system or vascular structures

Small Bowel Duplications
45% of intestinal duplications
Two forms: Tubular and Cystic

Tubular
-Usually occur on mesenteric side
-Share a blood supply with the intestine
-Gastric mucosa in 80%

Cystic
-Most commonly found at the ileocecal junction
-cysts shares a common blood supply and wall with ileum
-Gastric mucosa found within 20%

Presentation
75% present in first 2 years of life
80% present with bowel obstruction
Other presenting signs include melena, abdominal mass and perforation
Diagnosis is most often made at laparotomy

Treatment
Treatment is operative resection if feasible
– Cystic and short tubular duplicationare ideal candidates for resection which usually involves resection of the duplication and juxtaposed small bowel, but resection of cyst alone can compromise blood supply.

Long tubular duplications present a special problem
– Resection not an option due to length of small bowel involved
– Wrenn method: Separation of mucosa from muscular cuff. This may cause ischemia of adjacent bowel
– Other options: resection of connection between ileum and duplication

Colonic Duplications
– 14% of duplications
– Three types: Cystic, Tubular Appendiceal (duplications of the appendix)

Presentation
– Vomiting
– Abdominal pain
– Abdominal mass
– Urinary retention
– Volvulus
– Perforation

Diagnosis
– CT scan
– Barium enema
– Ultrasound
– Laparotomy

Treatment
Cystic: Surgical resection of cyst and adjacent normal bowel with anastomosis
Appendix Duplications: Appendectomies
Tubular: May not require or be amenable to treatment in all cases. Treatment must be individualized based on anatomic situation. May have two perineal ani with normal anal sphincters. Some are asymptomatic. Symptomatic duplications can be resected.

Duplication in females with fistulae
Rectovaginal or rectoperineal fistula
Constipation or obstruction of duplicated colon

Duplication in males with fistulae
Rectourinary fistula and functioning perineal anus
May have bifid scrotum or double penis
Duplication without fistulae with imperforate anus
May have two anal dimples or one functioning anus and second anal dimple

Duplications with other anomalies
Tubular duplications have the highest incidence of skeletal and urinary anomalies
– Almost all have intestinal obstruction
– Single perineal anus with communicating duplication
– Suspected in those with urethral or bladder duplication
– May be asymptomatic

Treatment options
– Distal part of duplicated colon can be joined with normal colon
– Distal part of duplication can be resected
– Fistulas to urinary system or genitalia should be excised appropriately

Rectal Duplications
4% of duplications
Present at median age of 17 months
More common in females

Presentation
– Asymptomatic mass
– Constipation
– Rectal bleeding
– Rectal prolapse
– Tenesmus

Characteristics

20-40% have a fistula to the rectum or skin
Occur in the posterior midline as a cone-shaped dimple just above or below anal verge
Gastric mucosa occurs in 10%

Treatment
– Resection of entire lesion
– Resection of mucosa
– May undergo malignant degeneration

Conclusion
Intestinal duplications may occur anywhere from mouth to anus.
Small bowel duplications are the most common.
Duplications are often associated with gastric mucosa and can lead to complications such as perforation, bleeding or malignant degeneration.
Treatment of choice is the resection of duplications unless associated with normal GI tract. These may require special consideration.