Spontaneous perforation of the colon and rectum complicating anorectal malformations in neonates.
Background: Spontaneous perforation of the colon is a rare complication in neonates with anorectal malformations (ARMs). There are no detailed studies concerning this complication.
Methods: A retrospective review of hospital records between 1994 and 2010 revealed 8 cases of bowel perforation among 136 cases of ARM. Eighteen additional cases were culled from the literature by searching Pubmed, Indmed, Embase, and Google Scholar.
Results: Perforations occurred more commonly in males with ARM (85%). Low and high anomalies were equally affected. The median age at diagnosis was 48 hours. Pneumoscrotum and abdominal wall erythema were occasionally suggestive of perforation. In addition to the Rigler sign and collapsed bowel on plain radiographs, a newly described "rectal-tail sign" was useful in recognizing pneumoperitoneum in the lateral view invertogram. A lower midline incision offered optimal surgical access. Two distinct patterns of perforation were identified: type 1 (88%) occurred before surgical decompression of the obstructed colon, whereas type 2 (12%) occurred postoperatively. Type 1 cases were subdivided into cecal (type 1a, 16%), transverse colon (type 1b, 8%), rectosigmoid (type 1c, 60%), and miscellaneous (type 1d, 4%) perforations. Type 1a is best treated with cecostomy and distal colostomy; type 1b, with exteriorization of the perforation; and types 1c and 1d, with closure of the perforation and proximal colostomy. Dense fibrous adhesions caused by extravasated meconium posed technical difficulty during the definitive pull-through operation and was responsible for considerable morbidity. The overall mortality was 19%.
Conclusions: Colorectal perforation is associated with considerable morbidity and mortality in neonates with ARM. Radiographs rather than clinical examination should be relied on for diagnosis of bowel perforation in ARM. Treatment options are chosen according to the subtype of perforation. Because most perforations occurred more than 24 hours after birth, early referral and surgical decompression of the colon may avoid this complication.