An unusual cause of intestinal obstruction: Intramural cystic duplication of gut at Ileocecal Junction

Acute intestinal obstruction is a common surgical emergency in children. Bands, adhesions, intussusceptions, volvulus etc are the usual causes. Duplication of gut is rare . Pre-operative diagnosis is difficult. Ultrasound scan is recommended. Out of 676 cases of pain abdomen in children one was diagnosed as duplication of gut by ultrasound study . Correct preoperative diagnosis by means of imaging techniques is rare.


Introduction
Acute intestinal obstruction is a common surgical emergency in children. Bands, adhesions, intussusceptions, volvulus etc are the usual causes. Duplication of gut is rare 1 . Pre-operative diagnosis is difficult. Ultrasound scan is recommended. Out of 676 cases of pain abdomen in children one was diagnosed as duplication of gut by ultrasound study 2 . Correct preoperative diagnosis by means of imaging techniques is rare 1 .

Case report
A 1 year 4 month old female child of consanguineous marriage with delayed milestone presented with complaints of intermittent distension of abdomen associated with vomiting for 7 days. Past history of recurrent distension of abdomen and occasional vomiting were present.
On examination she was anemic. Abdomen was distended and tender with increased bowel sounds. There was no localization of tenderness.

Investigations:
Haemoglobin was 7 gm%. X-ray abdomen showed multiple fluid levels with distended small intestine. Ultrasound study confirmed the diagnosis of acute intestinal obstruction but failed to detect any cyst separately from the fluid filled intestine.

Surgery:
On exploration site of obstruction was located at ileocecal region. There was no intussusception and mass was felt in the terminal ileum causing intestinal obstruction. (Figure 1)

Discussion
Duplication of gut is cystic or tubular structures that are in intimate with portion of intestine 3 . The tubular duplication usually communicates with the adjacent intestines, whereas the cystic duplication tends to be completely separate. The mucosal lining is always representative of some part of the alimentary tract. The presence of gastric mucosa has the risk of peptic ulceration with the possible complication of haemorrhage or perforation. Cystic duplication is endothelium lined structure enclosed in a common muscular wall with its adjacent segment of the bowel. Triplication of gutembryogenesis of tubular and cystic small intestine duplication has been reported 4 . Rarely cyst can attain huge size 5 .
There is no unified embryologic explanation for all duplications 3,4 . Lewis and Thyng in 1907 postulated the remnants of the outpouching of the developing fetal intestine between sixth and eight weeks of intrauterine life between the leaves of mesentery. Bremer in 1944 suggested error of recanalization of epithelial plug. This theory is based on the hypothesis that various portion of the alimentary tract become completely occluded by epithelial plug. Failure of canalisation by coalescence of vacuoles could conceivably result in the formation of duplication cysts. There is no convincing evidence to support the occlusion theory, and it fails to explain why duplications are restricted to the mesenteric aspect of the intestine. In 1954 Fallon et al proposed that duplication may result from failure of normal separation during the fourth week of development of the gut endoderm and the neural tube. Should complete separation of these two germ cell layers fail to occur, a cord of cells from the dorsal aspect of the developing gut will be pulled backward towards the developing vertebral column. This results into duplication of gut and explains the association of vertebral anomaly 6 . Rare association of tubular duplication of colon with subglottic stenosis is also reported 7 . In this case sequestration of intestinal mucosa is likely cause.
Resection and anastomosis is the choice of operation. This procedure is not applicable in situation in which excision will endanger structures like duodenum, where marsupialisation is carried out 6 .