Patchy innervation confirmed in pull-through bowel with normal conventional biopsy results in Hirschsprung's disease - the benefit of circumferential biopsying.

The effectiveness of pull-through for Hirschsprung's disease is dependent on accurate identification of normoganglionic bowel in intraoperative biopsy specimens. We report 2 cases of patchy innervation of pull-through bowel in children with Hirschsprung's disease only identified by circumferential biopsying. Case 1 was an 8-month-old boy. During laparoscopy-assisted transanal endorectal pull-through, extra biopsies of bowel were taken circumferentially, 2 cm proximal to the level of normoganglionosis confirmed by laparoscopic colon biopsies. Aganglionosis was found at 3 o'clock, suggesting that bowel innervation at this level was patchy. Circumferential biopsies were performed a further 2cm proximally, and all sites were normoganglionic. This level was used for pull-through with excellent outcome. Case 2 was a 27-day-old boy. Similarly, extra biopsies were taken circumferentially, 2cm proximal to the level of "normoganglionosis" as indicated by conventional biopsying. Normoganglionosis was found only at 3 o'clock, while all other sites were hypoganglionic. A further series of circumferential biopsies was performed 2 cm proximally and hypoganglionosis was still identified, but only at 6 o'clock. Circumferential biopsies were repeated another 2cm proximally, and all sites were normoganglionic. We recommend circumferential biopsies be performed routinely to prevent bowel with patchy innervation from being used for pull-through and possibly causing postoperative bowel dysmotility in a subgroup of Hirschsprung's disease patients.