Transanal rectal mucosectomy and partial internal anal sphincterectomy for Hirschsprung's disease

Hirschsprung-associated enterocolitis (HAEC) is a serious complication of Hirschsprung's disease (HD), with generalized sepsis and high mortality rate. Although the surgical correction of HD is mostly successful, challenges remain in the management of children with repeated episodes of enterocolitis. The authors describe a novel modification of transanal rectal mucosectomy and partial internal anal sphincterectomy (TRM-PIAS) for HD.

One hundred twenty-seven HD children aged from 8 days to 16 years who successfully underwent TRM-PIAS were reviewed. TRM-PIAS was carried out circumferentially along the anorectal line. Anterior dissection was conducted between the rectal submuscosal layer and the rectal muscular sleeve. The posterior dissection was performed along the plane between internal and external anal sphincters. Normal colon was pulled through and anastomosed to anal mucosa. Aganglionic segment, rectal mucosa, part of internal anal sphincter and posterior rectal muscular cuff were removed. Twenty-five age-matched children without defecation dysfunction were used as the control group in the study of anal resting pressure.

Patients were followed up for 6-12 years (median: 8.2 years). The median age at last follow-up was 12.2 years (7.2-20.1 years). The incidence of enterocolitis decreased from 33.9% (43/127) preoperatively to 1.6% (2/127) postoperatively (P<0.01). The incidence of constipation decreased from 100% (127/127) preoperatively to 2.4% (3/127) postoperatively (P<0.01). Soiling rate on postoperative 1 month was 32.3%. It gradually decreased to 1.6% 6 months later. Anorectal manometries showed that mean anal resting pressure was significantly reduced from 37.9±12.5 mm Hg preoperatively to 20.2±6.4 mm Hg on postoperative 1 month and 24.8±9.9 mm Hg on postoperative 6 months, which were similar to age-matched normal controls (27.9±9.6 mm Hg, P>0.05).

TRM-PIAS is effective in treatment of HD. It is associated with low postoperative HD-associated enterocolitis.