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Anal agenesis associated with rectal atresia
Anal Agenesis Associated With Rectal Atresia By A.K. Sharma, V. Chaturvedi, and A. Wakhlu Jaipur, I n d i a • The authors report an unusual case of anal agenesis associated with rectal atresia. Such an anomaly has been reported only once before. Coincidentally, this patient also had a rarely encountered skeletal anomaly--unilateral cleft foot.
Copyright © 1995 by W.B. Saunders Company "I~ECTAL MEMBRANE
INDEX WORDS: Rectal atresia; imperforate anus.
CASE REPORT A full-term baby weighing 2 kg and having a high anorectal malformation (as suggested by the Wangensteen-Rice criteria on an invertogram) first presented to our department 1 year ago. Clinical examination showed associated anomalies of paraaxial skeleton, including the rare anomaly of unilateral cleft foot, described elsewhere. 1The sacrum was normal. No other abnormalities of gastrointestinal, genitourinary, or cardiovascular systems were present. A left transverse loop colostomy was performed. The patient was readmitted at 1 year of age for definitive surgery. A distal colostogram performed preoperatively suggested anorectal agenesis without fistula (Fig 1). During exploration via the posterior sagittal approach, a rare anoreetal malformation was noted (Fig 2). It was a case of membranous rectal atresia associated with anal agenesis (Fig 3). The blind intervening segment of the rectum,
-V-'SAGITTAL V/EW _~.. Fig 2. Line diagram shows the rectal atresia and anal agenesis.
between the atresia and the anal site, was 5 em long. Excision of the membranous septum was performed with electrocautery. The distal end was brought down easily to the proposed and site, without extensive dissection. Anal dilatation was begun on the 14th postoperative day. Histopathologic examination of the excised septum showed the muscle coats of the rectum (Fig 4). The child is awaiting colostomy closure.
DISCUSSION A n a l a g e n e s i s a s s o c i a t e d w i t h r e c t a l a t r e s i a is a r a r e a n o r e c t a ! m a l f o r m a t i o n r e p o r t e d o n l y o n c e previously. 2
Fig 3. Intraoperative photograph shows the membranous rectal septum at the top of the intervening segment.
Fig 1. Distal Ioopogram shows high termination of the bowel.
Journa/ of Pediatric Surgery, Vo130,No 1 (January),1995:pp 113-114
From the Department of Pediatric Surgery. S.M.S. Medical College &Associated S.P.M.C H.L, Jaipur, India. Address reprint requests to A.K. Sharma, MD, B-2, Doctor's Bungalows, Gangwal Park, Yaipur 302 004, India. Copyright © 1995 by W.B. Saunders Company 0022-3468/95/3001-0029503. O0/ 0 113
114
SHARMA, CHATURVEDI, AND WAKHLU
The lesion cannot be explained on the basis of a single embryological insult. Anal agenesis results from the absence of the anal pit, owing to developmental arrest at the 16-ram stage (6-week embryo); rectal atresia results from a vascular accident occuring much later, between the 65-ram and ll2-mm stages (13- to 14-week embryo).3 We believe that the intervening rectal segment should not be discarded because dissection to do so may damage the vas, seminal vesicles, and nervi ergenti. Pena observed that resection or exclusion of the rectum, as done in abdominoperineal procedures and endorectal dissections, results in an increased risk of postoperative diarrhea and hampers achievement of fecal continence.4 The blood supply of the blind segment would not be jeopardized if only a limited dissection, to achieve a comfortable anoplasty, is performed. The posterior sagittal approach was the most suitable for reconstructing this anomaly, which would have been missed even intraoperatively with another procedure. In the previous case, even magnetic resonance imaging was unsuccessful in diagnosing the condition,z REFERENCES 1. Sharma AK, Sarin YK: Congential cleft foot (lobster-claw): An unusual association of ano-rectal malformation. Ind Pediatr 29:1295-1297, 1992 Fig 4. Photomicrograph of the rectal septum shows the muscle coat of the rectum,
2. Martinez Frontanilla LA: Double atresia of the hindgut: J Pediatr Surg 26:811, 1991
We believe that the designation "double atresia of the hindgut," as proposed earlier, is inappropriate because it is anal agenesis--not a "second" rectal atresia--that occurs toward the distal end of the blind rectal segment.
3. Stephens FD, Smith ED: Anorectal Malformations in Children. Chicago, IL, Year Book Medical, 1971, pp 98, 126 4. Pena A: Current management of anorectal anomalies. Surg Clin North Am 72:1403-1416, 1992
Copyright © 1995 by W.B. Saunders Company "I~ECTAL MEMBRANE
INDEX WORDS: Rectal atresia; imperforate anus.
CASE REPORT A full-term baby weighing 2 kg and having a high anorectal malformation (as suggested by the Wangensteen-Rice criteria on an invertogram) first presented to our department 1 year ago. Clinical examination showed associated anomalies of paraaxial skeleton, including the rare anomaly of unilateral cleft foot, described elsewhere. 1The sacrum was normal. No other abnormalities of gastrointestinal, genitourinary, or cardiovascular systems were present. A left transverse loop colostomy was performed. The patient was readmitted at 1 year of age for definitive surgery. A distal colostogram performed preoperatively suggested anorectal agenesis without fistula (Fig 1). During exploration via the posterior sagittal approach, a rare anoreetal malformation was noted (Fig 2). It was a case of membranous rectal atresia associated with anal agenesis (Fig 3). The blind intervening segment of the rectum,
-V-'SAGITTAL V/EW _~.. Fig 2. Line diagram shows the rectal atresia and anal agenesis.
between the atresia and the anal site, was 5 em long. Excision of the membranous septum was performed with electrocautery. The distal end was brought down easily to the proposed and site, without extensive dissection. Anal dilatation was begun on the 14th postoperative day. Histopathologic examination of the excised septum showed the muscle coats of the rectum (Fig 4). The child is awaiting colostomy closure.
DISCUSSION A n a l a g e n e s i s a s s o c i a t e d w i t h r e c t a l a t r e s i a is a r a r e a n o r e c t a ! m a l f o r m a t i o n r e p o r t e d o n l y o n c e previously. 2
Fig 3. Intraoperative photograph shows the membranous rectal septum at the top of the intervening segment.
Fig 1. Distal Ioopogram shows high termination of the bowel.
Journa/ of Pediatric Surgery, Vo130,No 1 (January),1995:pp 113-114
From the Department of Pediatric Surgery. S.M.S. Medical College &Associated S.P.M.C H.L, Jaipur, India. Address reprint requests to A.K. Sharma, MD, B-2, Doctor's Bungalows, Gangwal Park, Yaipur 302 004, India. Copyright © 1995 by W.B. Saunders Company 0022-3468/95/3001-0029503. O0/ 0 113
114
SHARMA, CHATURVEDI, AND WAKHLU
The lesion cannot be explained on the basis of a single embryological insult. Anal agenesis results from the absence of the anal pit, owing to developmental arrest at the 16-ram stage (6-week embryo); rectal atresia results from a vascular accident occuring much later, between the 65-ram and ll2-mm stages (13- to 14-week embryo).3 We believe that the intervening rectal segment should not be discarded because dissection to do so may damage the vas, seminal vesicles, and nervi ergenti. Pena observed that resection or exclusion of the rectum, as done in abdominoperineal procedures and endorectal dissections, results in an increased risk of postoperative diarrhea and hampers achievement of fecal continence.4 The blood supply of the blind segment would not be jeopardized if only a limited dissection, to achieve a comfortable anoplasty, is performed. The posterior sagittal approach was the most suitable for reconstructing this anomaly, which would have been missed even intraoperatively with another procedure. In the previous case, even magnetic resonance imaging was unsuccessful in diagnosing the condition,z REFERENCES 1. Sharma AK, Sarin YK: Congential cleft foot (lobster-claw): An unusual association of ano-rectal malformation. Ind Pediatr 29:1295-1297, 1992 Fig 4. Photomicrograph of the rectal septum shows the muscle coat of the rectum,
2. Martinez Frontanilla LA: Double atresia of the hindgut: J Pediatr Surg 26:811, 1991
We believe that the designation "double atresia of the hindgut," as proposed earlier, is inappropriate because it is anal agenesis--not a "second" rectal atresia--that occurs toward the distal end of the blind rectal segment.
3. Stephens FD, Smith ED: Anorectal Malformations in Children. Chicago, IL, Year Book Medical, 1971, pp 98, 126 4. Pena A: Current management of anorectal anomalies. Surg Clin North Am 72:1403-1416, 1992