Abstract
The omphalomesenteric or vitelline duct is a remnant of the embryonic yolk sac which connects the yolk sac to the gut in the developing embryo. Involution is the natural history however a number of anomalies are found due to persistence of partial or complete omphalomesenteric duct. Complete patency of omphalomesenteric duct with prolapse is a rare entity that requires early surgical correction to prevent complications. Here we report 2 newborns with prolapse of patent omphalomesenteric duct, one with life threatening complication like gangrene of prolapsed distal ileum, treated successfully.

Case Report

Fig. 1 : Prolapsed OM duct.

Fig. 2 Prolapse OM duct with gangrene of the distal loop.

Case 1
A 20 days old, full-term male newborn weighing 3 kg, presented with a shiny red rounded swelling protruding out from the umbilicus. The umbilical stump fell of f on 8th day and the mass appeared on 15th day of life. Mother has noticed that the baby has started passing stools from the ‘umbilical swelling’ since last two days. The swelling increased in size on crying and assumed ‘Y’ or ‘T’ shape. It showed two openings, opposite each other at the base (Fig. 1). Both the openingscould be canulated with a lubricated feeding tube. Baby was passing stools from one of the openings which obviously was proximal bowel loop. The haemogram, serum electrolytes, renal function tests were normal. The baby was operated via a circumferential infra-umbilical incision extended on right side. A short omphalomesenteric duct was found, connecting the ileum to the umbilicus. The omphalomesenteric duct with adjoining ileum was resected and end-to-end anastomosis was done. The circular defect in abdominal wall was closed with an intra-dermal purse-string like suture approximating the skin edges and tucking in down to rectus sheath. The baby tolerated the surgery well and was discharged on 10th postoperative day. The histological evaluation of the omphalomesenteric duct showed presence of all layers of small bowel without any ectopic tissue. Baby is thriving well and is on regular follow up.

Case 2
A 15 days old male newborn presented with a large umbilical mass. It had appeared on 8th day, 2 days after the umbilical stump has fallen off. Initially the mass was reducible and bright red in colour, but increased in size as baby cried and has become irreducible and blackish since last three days. Baby passed stools from an opening located at the base of the mass. On examination the baby was haemodynamically stable. There was an oblong, spiral shaped umbilical mass of size 6 x 15 cm lined with mucous membrane which was black to brown in colour (Fig. 2). There was fowl smelling discharge from the mass. An opening of proximal bowel could be identified at the base of the swelling through which stools were coming out. The distal intestinal opening was obscured because of oedema. Baby was kept nil by mouth and intravenous fluids were started. Intravenous Ceftriaxone, Gentamicin, and metronidazole were started. The swelling was covered with a normal saline and povidone-iodine soaked gauze while preparations were done for surgery next morning. Haemogram, renal function tests were normal. Urine output was adequate. Laparotomy was done with a circumferential infra-umbilical incision extended on right side. The proximal small bowel loop was easily identified and was found healthy. The prolapsed distal ileum was showing gangrenous changes. Hence the omphalomesenteric duct connecting umbilicus with ileum with 15 cm of prolapsed, unviable reconstruction was done as described above. The baby was kept in NICU postoperatively and required blood transfusion, fresh frozen plasma. The intravenous antibiotics were continued for 10 days. He was discharged on 14th postoperative day. The histology of the resected specimen showed gangrenous ileum and omphalmomesenteric duct. At the timing of writing the report, the baby is asymptomatic and thriving well.

Discussion

The omphalomesenteric (OMD) or vitellointestinal duct (VID) is a channel connecting the embryonic mid-gut with the yolk sac. The duct involutes by seventh to the ninth week of gestation as placenta takes over function of nutrition. Omphalomesenteric duct anomalies like umbilical adenoma, Meckel’s diverticulum or a patent omphalomesenteric duct occur in approximately 2 of newborns. In 6% of these a patent omphalomesenteric duct is found.1-3 The patent omphalomesenteric duct is a fistulous communication between the ileum and the umbilicus. It presents with the discharge of enteric contents which may be serous, bilious, or feculent via umbilicus.1 The duct and adjacent ileum occasionally intussuscept and from the umbilicus creating typical mucosa-covered “inverted T” shaped mass where openings of the proximal and distal ileum can be identified lying opposite to each other.2-6 It needs to be differentiated from umbilical adenoma and patent urachus. Umbilical adenoma is mucosa-lined remnant of the OM duct adjacent to abdominal wall. It gives rise to mucoid discharge and a sinogram will show a blind tract while contrast study through the lumen of patent OM duct will show communication with terminal ileum. In patent urachus the drainage is urinary in nature and a contrast study will confirm communication with urinary bladder.
With progressive prolapse and venous congestion there is a danger of vascular compromise of the prolapsed loop because of compression by umbilical ring over the blood vessels. It leads to gangrene of the prolapsed segment. This is a potentially lethal condition and should be identified earlier and a prompt surgical correction should be done.
The cases described here show two extremes of prolapse of patent omphalomesenteric duct. The first case presented earlier, had minimal prolapse and hence both the proximal and distal bowel loops were healthy. The other patient unfortunately had vascular compromise of prolapsed distal ileum leading to gangrene, which required resection. Resection of gangrenous bowel segment in a newborn is a major procedure involving high morbidity and mortality.3 The baby may require a long hospital stay in intensive care unit, which may increase the expenses of the family. If the baby is in septic shock due to gangrene, one may have to do an ileostomy and mucous fistula after resection of the gangrenous bowel as a life saving procedure first and establish bowel continuity at a later stage. In this approach the baby is likely to suffer from water and electrolyte losses via ileostomy and requires another major procedure later. Hence early diagnosis and surgical treatment of this classical clinical condition are necessary to prevent complications.1,4-9

References

1. Cilley RE, Krummel TM. Disorders of the umbilicus, In: O’Neill JA, Rowe MI, Grosfeld JL, Fonkalsrud EW, Coran AG (eds), Pediatric Surgery (5th ed). St. Louis: Mosby-Year Book, 1998;
   1029-43.
2. Yesim Zafer, Sule Yigit, Aydyn Turken, Gulsevin Tekinalp. Patent Omphalomesenteric duct. Turk J Med Sci 2000; 30 : 83-5.
3. Yamada T, Seiki Y, Ueda M, et al. Patent omphalomesenteric duct : a case report and review of Japanese literature. Asia Oceania J Obstet Gynaecol 1989; 15 (3) : 229-36.
4. Mustafa R. Double intussusception of the small bowel through a patent villointestinal duct. Br J Surg 1976; 63 : 452.
5. Storms P, Pexsters J, Vandekerkhof J. Small omphalocele with ileal prolapse through patent omphalomesenteric duct. A case report and review of literature. Acta Chir Belg 1988; 88 : 392-4.
6. Moore TC. Omphalomesenteric duct malformations. Sem Pediatr Surg 1996; 5 (2) : 116-23.
7. Lee WY, Lee SK, Kim HH. Patent Omphalomesenteric duct remnants: report of 4 cases. J Korean Assoc Pediatr Surg 1997; 3 (2) : 148-51.
8. O’Donnell KA, Glick PL, Caty MG. Pediatric umbilical problems. Pediatr Clin North Amer 1998; 45 : 791-9.
9. Vane DW, West KW, Grosfeld JL. Vitelline duct anomalies - experience with two hundred and seventeen childhood cases. Arch Surg 1987; 122 : 542-7.