Small bowel obstruction due to a persistent omphalomesenteric duct

JBR–BTR, 2005, 88: 175-177.

SM ALL BOWEL OBSTRUCTION DUE TO A PERSISTENT OM PHALOM ESENTERIC DUCT M . Herm an 1, S. Gryspeerdt 1, D. Kerckhove2, I. M atthijs3, Ph. Lefere1 We report a case of a M eckel diverticulum connected w ith the umbilicus through a fibrotic cord causing small bowel obstruction. On admission, the patient presented w ith an acute abdomen. A plain upright radiography of the abdomen, an ultrasonography of the abdomen, and an enema w ith gastrografin were performed, show ing a small bowel obstruction at the level of the pre-terminal ileum, w ithout revealing the cause. Urgent surgery followed, show ing a persistent omphalomesenteric duct connected to the abdominal wall through a fibrotic cord, w ith a secondary volvulus of the small bowel. The remnant was resected and the volvulus reduced. The post-operative course was uneventful. Because of the serious complications and even possible mortality due to ischemic disease of the affected small bowel the possibility of a complicated persistent omphalomesenteric duct should be kept in mind, even if the preoperative work-up does not reveal a M eckel diverticulum. Key-word: Intestines, stenosis or obstruction.

Anom alies of the om phalom esenteric duct occur in approxim ately 2% of the population and lead to sym ptom atic intra-abdom inal com plications in 20% (1). The m ost com m on anom aly is the M eckel diverticulum , w hich causes sym ptom s of painless rectal bleeding and intestinal obstruction (due to intussusception) in older infants. In new borns and younger children, how ever, om phalom esenteric duct rem nants m ost often cause intestinal obstruction due to volvulus of the sm all intestine around a fibrous duct rem nant. The sm all intestinal obstruction is usually of high grade, and bow el necrosis is com m on w hich can lead to m ortality (2-4). This article gives a review concerning the om phalom esenteric duct and its possible com plications. Know ledge of the (com plicated) om paholom esenteric duct condition is im portant to suggest the diagnosis to the pediatrician and surgeon. Case report A 3-year-old boy was adm itted to the hospital because of crying, vom iting, and absence of stools. The palpation of the abdom en w as painful. Laboratory tests w ere negative. Plain upright radiography of the abdom en, ultrasonography of the abdom en and an enem a w ith gastrografin w ere perform ed. Plain upright radiography show ed dilated sm all bow el loops w ith airfluid levels and an air-filled, norm al distended colon (Fig. 1), suggesting

Fig. 1. — Plain upright radiography of the abdom en show ing dilated sm all-bow el loops w ith air-fluid levels (arrow ) and an air-filled, norm al distended colon.

a distal sm all bow el obstruction. Ultrasonography show ed free fluid and an undefined m ass w ith fluid

From : Departm ent of 1. Radiology, 2. Surgery, 3. Pediatrics, Stedelijk Ziekenhuis Roeselare, Belgium . Address for correspondence: Dr S. Gryspeerdt, M .D., Departm ent of Radiology, Stedelijk Ziekenhuis Roeselare, Brugsesteenw eg 90, B-8800 Roeselare, Belgium .

filled sm all bow el loops, closely located to the abdom inal w all (Fig. 2). The target-sign or pseudokidney sign, typically found in case of intussusception, was not seen. An enem a w ith gastrografin was perform ed subsequently, and show ed a non-reducible obstruction at the term inal ileum w ith a norm al-sized

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Fig. 2. — Ultrasonography of the abdom en show ing free fluid (arrow s) and fluid filled sm all bow el loops, closely located to the abdom inal wall.

colon (Fig. 3). All these im aging findings are consistent w ith a distal sm all-bow el obstruction. Surgical exploration show ed a volvulus of the distal ileum around a persistent om phalom esenteric duct rem nant (Fig. 4). The rem nant consisted of a M eckel diverticulum affixed to the um bilicus by a fibrous cord. The rem nant was resected and the volvulus reduced. The post-operative course was uneventful and the patient was discharged on the sixth postoperative day. Discussion The om phalom esenteric or vitelline duct is the com m unication betw een the yolk sac and the prim itive m idgut. The duct starts closing during the eighth or ninth w eek of gestation and disappears soon after. If there is incom plete resorption, how ever various anom alies occur (1). Those anom alies occur in approxim ately 2% of the population. The m ale-to-fem ale ratio is 3:1. The persistence of an entirely open vitelline duct leads to an um bilicointestinal fistula. The vitelline duct m ay rem ain open only at its outer portion, resulting in an incom plete um bilical fistula, called um bilical

Fig. 3. — An enem a w ith gastrografin show ing a non-reducable obstruction at the term inal ileum (arrow and m agnified view ) w ith a norm al-sized colon.

sinus. The m ore proxim al part in such case becom es transform ed into a fibrous cord. Som etim es the vitelline duct com pletely transform s into a fibrous cord, connecting the sm all intestine w ith the um bilicus. In som e cases the fibrous cord presents w ith an interm ediate cyst. M ost com m only the om phalom esenteric duct persist as a sacculation or pouch attached to the ileum and is know n as M eckel diverticulum . Occasionally, the M eckel diverticulum rem ains affixed to the um bilicus by a fibrous cord, as was the case in this patient (Fig. 5). A com plicated persistent om phalom esenteric duct is seen in 20% (24). 60% present w ithin the first tw o years of life. Intestinal bleeding and inflam m ation-perforation are the m ost frequent com plications in older children. Obstruction is a frequent com plication in younger children. Obstruction m ay be secondary to intusception, w ith a M eckel diverticulum as the lead point, or sec-

ondary to volvulus, torsion and strangulation and than is m ostly associated w ith a fibrous band. Other rare com plications are incarceration of the duct in a Littre’s hernia, a phytobezoar, an enterolith, or even RIP in the duct. The clinical presentation is nonspecific: crying, vom iting, rectal bleeding, absence of stools and peristalsis, painful abdom en. Laboratory tests m ostly show elevated inflam m atory levels. Radiological findings are usually non-specific (5). A plain upright radiography show s a distal sm allbow el obstruction w ith fluid levels w ith or w ithout air in a norm al colon. Abdom inal film s som etim es dem onstrate a soft tissue m ass, an enterolith or very rarely portal venous gas (caused by perforation), indicating sm all bow el necrosis. Ultrasonography m ostly gives nonspecific signs as free fluid and inflam m ation. In case of intussusception the typical target sign is

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Fig. 4. — Intra-operative photograph after reduction of the sm all bow el show ing dilated sm all bow el (arrow ), M eckel diverticulum (arrow head) and fibrous cord (w hite sm all arrow ) w hich was affixed to the um bilicus. The fibrous band was the focal point for the sm all bow el volvulus.

seen. An enem a w ith safe contrast m edia show s a norm al colon (differential diagnosis w ith Hirschsprung), a non-reducible obstruction, som etim es a beak sign and a m edial deviation of the caecum w ith volvulus. Antegrade barium contrast study in patients w ith acute sm all bow el obstruction is not usually indicated since it m ay delay surgical intervention. If bow el necrosis is present spillage of barium into the peritoneum at the point of perforation m ay occur. With interm ittent partial obstruction, an antegrade study w ith dilute barium or the new er nonionic contrast m aterial m ay be helpful in determ ing the site of obstruction and m ay also dem onstrate the obstucted loop. A scan w ith Te 99 m pertechnetaat can be done to dem onstrate the M eckel diverticulum (gastric m ucosa). An angiography is done w hen there is persistent bleeding. In case of acute abdom en surgery w ith resection of the duct is necessary (4). Pre-operative diagnosis of the om phalom esenteric duct as the cause of sm all-bow el obstruction is not always feasible and is usually confirm ed w ith surgery. Nevertheless every radiologist m ust be aware of this condition w hen a child presents w ith a sm allbow el obstruction. A resection is also advocated w hen the om phalom esenteric duct is an incidental finding.

Fig. 5. — Draw ing show ing the various anom alies of the om phalom esenteric duct. a. The persistance of an entirely open vitelline duct leads to an um bilico-intestinal fistula; b. The vitelline duct m ay rem ain open only at its outer portion, resulting in an incom plete um bilical fistula, called um bilical sinus. The m ore proxim al part in such case is transform ed into a fibrous cord, attached to the sinus distally and proxim ally to the ileum ; c. The vitelline duct m ay also com pletely transform into a fibrous cord, connecting the sm all intestine w ith the um bilicus; d. In som e cases the fibrous cord presents w ith an interm ediate cyst; e. M ost com m only the om phalom esenteric duct persist as a sacculation or pouch attached to the ileum and is know n as M eckel diverticulum ; f. Occasionally, the M eckel diverticulum rem ains affixed to the um bilicus by a fibrous cord, as was the case in this patient.

Conclusion Considering the high frequency of sm all-bow el obstruction as a com plication of persistent om phalom esenteric duct and the high incidence of bow el necrosis w hich can lead to m ortality, the radiologist m ust be aware of this condition and is in a good position to suggest this possibility to the surgeon. References 1.

Vane D.W., West K.W, Grosfeld J.L.: Vitelline ductanom alies. Experience w ith 217 childhood cases. Arch Surg , 1987, 122: 542-547. 2. Kleiner O., Cohen Z., Finaly R., M ordehai J., M ares A.J.: Unusual

presentation of om phalom esenteric duct rem nant: a variant of m esodiverticular band causing intestinal obstruction. J Peduatr Surg , 2000, 35: 1136-1137. 3. Van der Zee D.C., Pull ter Gunne A.J., Rovekam p M .H., Bax N.M .: Ziektebeelden bij een persisterende ductus om phalo-entericus of resten ervan zijn niet altijd onschuldig. Ned Tijdschr Geneeskd , 1990, 134: 985-986. 4. Gaisie G., Curnes J.T., Scatliff J.H., et al.: Neonatal intestinal obstruction from om pahalom esenteric duct rem nants. AJR Am J Roentgenol , 1985, 144: 109-112. 5. Fenton L.Z., Buonom o C., Share J.C., Chung T.: Sm all intestinal obstruction by rem nants of the om phalom esenteric duct: findings on contrast enem a. Pediatr Radiol , 2000, 30: 165-167.