Standardised Functional Assessment in Females With Low Anorectal Malformation to Determine Need for Surgery

The indications for surgical treatment in females with anterior anus remain controversial. We analysed the clinical outcomes in two groups: those who underwent surgery and those who received conservative treatment. We propose a standardized assessment, focusing on functional aspects, to determine the necessity of surgical intervention.

A retrospective chart review was conducted on 24 girls who underwent examination under anesthesia (EUA) for an abnormal anal opening between June 2008 and March 2022. All patients were treated by a single surgeon at a tertiary pediatric surgery center. The mean age at EUA was 8 months, with children requiring surgery being younger (mean age: 6.5 months) than those who did not need surgery (mean age: 12.5 months). The mean anal size, measured using a Hegar dilator, was significantly larger in non-surgical cases (mean Hegar size: 13, p = 0.002). The ability of the sphincter to close the anus was observed in 56 % of children who did not require surgery but was absent in all those who underwent surgery (p = 0.028). Surgical intervention was deemed unnecessary when the anal opening was appropriate for the child's body weight and the anus closed upon contraction. During long-term follow-up (mean duration: 59 months), no additional surgeries were required. Previous treatments and bowel function at the last follow-up were also documented.

None of the patients managed conservatively went on to need any further surgical input.

In our series, patients who underwent surgery had a significantly smaller anal orifice (relative to age) on calibration and were more likely to have an orifice that did not close upon sphincter stimulation. When the anal opening is functionally adequate in size and the sphincter can close it-regardless of its anatomical position within the sphincter-a conservative approach is recommended. Notably, none of the patients managed conservatively required surgery later. Families need to be councelled that constipation may happen in the operated as well as in the non operated group.