Anal dilations following posterior sagittal anorectoplasty: Are they necessary in all patients?

Anal dilations (AD) following posterior sagittal anorectoplasty (PSARP) can have a psychological impact on patients and caregivers. We present our long-term results after changing the postoperative AD protocol to improve patient selection and avoid unnecessary ADs.

A retrospective study of patients undergoing PSARP in our institution from 2018 to 2023 was carried out. Demographic variables, ARM types, intraoperative Hegar (IH) and postoperative Hegar (PH) size after 3 weeks, need for dilations, and follow-up were reviewed. Protocol change includes outpatient measurement on postoperative week 3. If the caliber is lower than IH or than the normal caliber based on patient age, ADs are indicated.

36 patients (24 males) aged 8.2 ± 5.8 months at PSARP were included. The most frequent types of anorectal malformation (ARM) were rectoperineal (10), rectovestibular (10), and rectobulbar (10). IH size was 12 ± 1.2 mm. 3 weeks later, the caliber decreased in 29 patients (80.6%), with ADs being initiated in all of them. In 6 patients (16.7%), there were no differences in terms of size, which means ADs were not indicated. After a 40-month (range: 16-49) follow-up period, 6 (16%) patients had mucosal prolapse, with only 2 (5%) requiring surgical repair. None of the patients developed neoanal stricture.

The need for ADs following PSARP can be established based on outpatient neoanal measurement, by comparing neoanal size with IH size. Most patients require dilations, but there is a small group where the latter can be avoided without increasing the risk of stricture.