Normal Anal Sensibility in Patients Born With Anorectal Malformations

Objectives
Anal sensibility is crucial for fecal continence. We aim to investigate anal sensibility in patients diagnosed with different types of ARM, after various types of treatments, and according to the sacral ratio.

Methods
Retrospectively, we included 68 ARM patients (7 treated non-surgically and 61 surgically). All underwent anorectal function tests. We measured anal sensibility, the existence of a functional internal anal sphincter (IAS), and sacral ratio.

Results
The mean anal sensibility was 7.2 (SD 5.2). Normal anal sensibility was present in 40/60 patients, irrespective of the malformation type. Patients diagnosed with minor types had better anal sensibility than those with major types (5.1 vs. 8.4 mA, respectively, p = 0.007) and those treated non-surgically vs. surgically (2.7 vs. 7.7 mA, respectively, p = < 0.001). Anal sensibility was significantly better in patients who possessed an IAS than in patients without an IAS (6.4 and 9.2 mA, p = 0.038). Multivariable regression analysis demonstrated a relationship between anal sensibility and the existence of a functional IAS. Anal sensibility was not associated with the sacral ratio.

Conclusions
Normal anal sensibility can be present in ARM patients diagnosed with all types of ARM after they have been treated with corrective surgery. Anal sensibility was better in those with a functional IAS. This means that the IAS, present in the distal end of the fistula, should be spared as much as possible to preserve anal sensibility. In this way, aiming to maintain the best possible fecal continence.