Preoperative enzymo-histochemical diagnosis of dysganglionoses associated with anorectal malformations (ARM) with recto-vestibular and recto-perineal fistula

The posterior sagittal anorectoplasty (PSARP) is widely recognized as the best technique available today for the surgical treatment of anorectal malformations (ARM). However, different retrospective studies on the functional results of PSARP in the treatment of ARM have shown different postoperative degrees of constipation. In particular, even in patients with normal sacrum, about 70 % of operated ARM with vestibular fistula and about 50 % with perineal fistula can be complicated by fecal constipation and pseudoincontinence. In order to identify preoperatively whether ARM patients present abnormal innervation patterns of rectal pouch and fistula (as reported by Holschneider et al [7]), we decided to study suction rectal biopsies performed by introducing SBT100 rectal suction biopsy tool into the fistula at 6, 4, 3 and 2 cm from the meatus. To date, this approach has been adopted in 22 ARM cases (15 females and 7 males, age range 7 days - 4 years), 6 of them with recto-vestibular fistula and 13 with recto-perineal fistula. Biopsies were frozen in isopentane at liquid nitrogen temperature and cryostatic sections were studied by acetylcholinesterase (ACHE), succinic- dehydrogenase (SDH) and alpha-naphthylesterase (ANE) enzymo-histochemical techniques. The results concerning the innervation-type of fistula and proximal rectal pouch were confirmed by the biopsies obtained during PSARP. Our overall incidence of rectal innervation intrinsic disorders was 81.82 %. In particular, all our cases of vestibular fistula presented associated dysganglionoses. The incidence of associated Hirschsprung's disease was high, corresponding to 18 % of cases. Our results suggest that the high frequency of constipation in low forms of ARMS depends on primary intestinal neuronal malformations and it cannot be ascribed to 4a denervation secondary to rectal dissection and to PSARP procedure. We propose the introduction of this type of preoperative enzymo-histochemical diagnosis in ARM cases because it can select those patients with severe associated dysganglionoses. In our opinion, if this diagnosis is available preoperatively, PSARP can be performed without using abnormally innervated structures and reducing postoperative functional complications.