Congenital pouch colon associated with segmental dilatation of the colon

Congenital pouch colon associated with segmental dilatation of the colon

Congenital Pouch Colon Associated With Segmental Dilatation of the Colon By Rajiv Chadha, Sanjay Gupta, Ujjawal S. Tanwar, and J.K. Mahajan New Delhi,...

122KB Sizes 0 Downloads 104 Views

Congenital Pouch Colon Associated With Segmental Dilatation of the Colon By Rajiv Chadha, Sanjay Gupta, Ujjawal S. Tanwar, and J.K. Mahajan New Delhi, India

A 1-day-old boy who presented with an anorectal malformation (ARM) was found to have a segmental dilatation of the colon (SDC) associated with a typical congenital pouch colon (CPC) malformation. The distal colonic pouch terminated in a high colovesical fistula. The posterior portion of the perineal raphe´ was duplicated and ended in 2 anal dimples. Both dilated segments of the colon were excised. The similarity

between CPC and SDC is highlighted, and the possible embryogenesis of both conditions is discussed. J Pediatr Surg 36:1593-1595. Copyright © 2001 by W.B. Saunders Company.

C

fashioned in the right lower abdomen. Postoperative recovery was uneventful. Histologic examination of the resected segments showed normal colonic tissue with thinned-out musculature and normal ganglion cells. An abdominal ultrasonogram performed 1 month after surgery showed normal kidneys. The child currently is awaiting definitive surgery for the anorectal malformation.

ONGENITAL POUCH COLON (CPC) is an unusual condition in which a pouchlike dilatation of a shortened colon is associated with an anorectal malformation (ARM), usually of the high variety.1-4 Segmental dilatation of the colon (SDC) is another rare congenital malformation in which there is dilatation of a segment of colon of variable length, with the proximal and distal bowel being of normal caliber.5-9 In this report, we describe a 1-day-old boy in whom SDC was associated with a colonic pouch terminating in a high, colovesical fistula. To our knowledge, a similar case has not been reported earlier in the literature. CASE REPORT A 3.4-kg, 1-day-old boy, born after 38 weeks’ gestation presented with complaints of absence of the anal opening and abdominal distension. The mother was a healthy primigravida, and pregnancy had been uneventful. Examination showed a healthy, vigorous infant. There was moderate abdominal distension. Although the external genitalia were normal, just posterior to the scrotum, the median perineal raphe´ bifurcated to end in 2 anal dimples situated close together on each side of the midline (Fig 1). An invertogram showed a large globular air-fluid level on the left side of the abdomen with a similar, smaller shadow on the right side (Fig 2). The small bowel loops were displaced to the right side. The sacrum was normal. A diagnosis of CPC malformation was made, and the child underwent emergency surgery. At surgery, the terminal ileum was found to open into a large, globular colonic sac situated in the right lower abdomen and extending into the pelvis. A small stub of appendix was present on its surface (Fig 3). This dilated colonic segment was connected by a 2-cm length of normal colon to a larger colonic pouch on the left side that opened by a wide colovesical fistula into the middle of the posterior wall of the bladder. Both the dilated colonic segments were enormously distended with meconium and were thin walled. Tenia coli and haustrations were absent. The blood supply was from a large, marginal colonic artery coursing on the outer or lateral aspect. Owing to the complex nature of the anatomy, no attempt was made to preserve the colonic pouch. Both dilated segments were resected after division-ligation of the colovesical fistula. An end-ileostomy was Journal of Pediatric Surgery, Vol 36, No 10 (October), 2001: pp 1593-1595

INDEX WORDS: Pouch colon, congenital, colon, segmental dilatation, anorectal malformations.

DISCUSSION

Most large series describing CPC have been reported from centers in Northern India.1-4,10 CPC has been classified into 4 subtypes based on the length of normal colon proximal to the colonic pouch.3,10 In the more severe forms, there is either no normal proximal colon (type I) or only the cecum with a very short segment of normal colon (type II).3,10 These subtypes usually are associated with a high colovesical fistula in boys and a colovesical, colovaginal, or colocloacal fistula in girls.1-4,10 Frequently associated abnormalities include a Meckel’s diverticulum and appendiceal abnormalities such as absence of the appendix, a short stubby appendix, or appendiceal duplication.1-4,10 The less severe forms (types III and IV CPC) have a longer segment of normal proximal colon and usually a lower termination of the pouch and associated genitourinary fistula.10 The usual clinical presentation and radiologic findings in CPC malformations have been detailed in earlier reports.1-4 Preliminary surgery described for type I/II CPC includes excision of the pouch with a proximal enterostomy, a window colostomy of the pouch, or, subFrom the Department of Pediatric Surgery, Lady Hardinge Medical College and Kalawati Saran Children’s Hospital, New Delhi, India. Address reprint requests to Dr Rajiv Chadha, G-123, Vikaspuri, New Delhi-110018, India. Copyright © 2001 by W.B. Saunders Company 0022-3468/01/3610-0028$35.00/0 doi:10.1053/jpsu.2001.27066 1593

1594

CHADHA ET AL

Fig 1. Photograph of the perineum. Arrowheads point to the 2 anal dimples.

total resection of the pouch, tubularization of the remaining portion, and end-colostomy.1-4,10 The etiology of this condition is uncertain. In an earlier report,10 we had suggested that the primary abnormality is “defective organogenesis” or “primary dysplasia” of the distal-most segment of intestine, close to the descending urorectal fold. This defective segment could anchor the entire cloaca ventrally, prevent further descent of the urorectal septum, and interfere with the longitudinal growth of the hindgut (R. Spencer, personal communication, June 1997). During later development, the abnormal segment would dilate to form the colonic pouch.10 The similarity between CPC and SDC has been noted previously.11 Characteristic features of SDC include abrupt transition to normal proximal and distal bowel, hypomotility of the dilated segment, presence of ganglion cells, absence of tenia coli, and abundant serosal vascularization fed by a large, marginal colonic artery.5-9 All these features are seen in pouch colon malformations. Ectopic heteroplastic tissues have been found in the resected segment in some patients of segmental dilata-

Fig 2. Invertogram shows the high anorectal malformation with a large, globular air-fluid level on the left side and a smaller air-fluid level on the right side of the abdomen (arrowheads).

tion of the intestine,12,13 and ectopic pancreatic tissue was present in the colonic pouch in one patient with CPC.3 Appendiceal abnormalities also have been reported with SDC.14-16 These include absence of the appendix in a patient with segmental cecal dilatation16 and duplication of the appendix in 2 patients with SDC

Fig 3.

Diagrammatic representation of the operative findings.

POUCH COLON WITH SEGMENTAL COLONIC DILATATION

1595

involving the transverse or sigmoid colon, an ARM, and other abnormalities.14,15 “Impairment of intestinal organogenesis,”17 “primary dysplasia,”13 and “congenital damage to the myenteric plexus”18 have all been suggested as etiologic factors responsible for segmental dilatation of the intestine. The presence of a short segment of normal colon between the 2 dilated segments suggests the possibility that during early development (around fourth week of gestation), defective organogenesis may have occured at

2 sites in the terminal hindgut close to the primitive cloaca. The distal segment would dilate to form the colonic pouch with the colovesical fistula, while the proximal, abnormally developed portion would form the dilated segment of colon. The bifurcation of the perineal raphe´ posterior to the scrotum and the presence of 2 anal dimples is difficult to explain. It does, however, coincide with the presence of 2 distinct, although connected, dilated segments of the terminal hindgut lying side by side in the pelvis.

REFERENCES 1. Chadha R, Bagga D, Malhotra CJ, et al: The embryology and management of congenital pouch colon associated with anorectal agenesis. J Pediatr Surg 29:439-446, 1994 2. Kalani BP, Sogani KC: Short colon associated with anorectal agenesis: Treatment by colonorraphy. Ann Pediatr Surg 1:83-85, 1984 3. Narasimharao KL, Yadav K, Mitra SK, et al: Congenital short colon with imperforate anus (pouch colon syndrome). Pediatr Surg Int 5:124-126, 1990 4. Wakhlu AK, Wakhlu A, Pandey A, et al: Congenital short colon. World J Surg 20:107-114, 1996 5. Brawner J, Shafer D: Segmental dilatation of the colon. J Pediatr Surg 8:957-958, 1973 6. de Lorimier AA, Benzian SR, Gooding CA: Segmental dilatation of the colon. Am J Roentgenol 112:100-105, 1971 7. Helikson MA, Schapiro MB, Garfinkel DJ, et al: Congenital segmental dilatation of the colon. J Pediatr Surg 17:201-202, 1982 8. Swenson O, Rathauser F: Segmental dilatation of the colon. Am J Surg 97:734-739, 1959 9. Takehara H, Komi N, Hino M: Congenital segmental dilatation of the colon: Report of a case and review of the literature. Pediatr Surg Int 4:66-68, 1988 10. Chadha R, Bagga D, Mahajan JK, et al: Congenital pouch colon revisited. J Pediatr Surg 33:1510-1515, 1998

11. Sarin YK, Singh VP: Congenital segmental dilatation of the colon. Ind Pediatr 32:116-118, 1995 12. Aterman K, Abaci F: Heterotopic gastric and esophageal tissue in the colon. Am J Dis Child 113:552-559, 1967 13. Irving IM, Lister J: Segmental dilatation of the ileum. J Pediatr Surg 12:103-112, 1977 14. Narasimhan KL, Roychoudhuri S: Duplication of appendix with segmental dilatation of the colon and vesical exstrophy. Pediatr Surg Int 8:452, 1993 15. Rizalar R, Sarac A, Gork AS, et al: Duplication of appendix with segmental dilatation of the colon, myeloschisis and anal atresia. Eur J Pediatr Surg 6:112-113, 1996 16. Uroz-Tristan J, Poenaru D, Urgelles XG, et al: Segmental cecal dilatation with absent appendix: A case of failure of appendiceal regression. Eur J Pediatr Surg 6:373-374, 1996 17. Hemet J, Fouin-Fortunet H, Fessard J, et al: Dilatation segmentaire ne´onatale del’intestin greˆle. Ann Anat Pathol 24:161-170, 1979 18. Mathe´ JC, Khrairallah S, Phat Vuong N, et al: Dilatation segmentaire du greˆle a` re´ve´lation ne´onatale. E´tude par impre´gnation argentique des plexus myente´rique. La nouvelle Presse Med 11:265266, 1982