Transperineal ultrasound for anorectal malformation assessment at a tertiary hospital in Nairobi, Kenya

Abstract

Introduction: Imaging has a vital role in management of anorectal malformations (ARM) with the pressure colostogram and MRI being preferred to assess the perineal anatomy. The pressure colostogram is the widely-accepted ‘gold standard’ imaging tool for outlining fistulae and pouch to perineum (P-P) distance. assessing the pouch to perineum (P-P) distance.

Recent studies have shown that the transperineal ultrasound (TPUS), a non-invasive imaging technique, can be as effective as the pressure colostogram in the preoperative management. This study aims to compare the effectiveness of the transperineal ultrasound to the distal colostogram in the radiological management of ARM at the Kenyatta National Hospital (KNH).

Methods: This was a cross sectional analytic study carried out at the KNH pediatric surgical ward and clinic. Patients with ARM with no history of surgical intervention were recruited into the study and routine transperineal ultrasound performed with no prior preparation required. The findings were compared to distal pressure colostogram findings and in other cases correlated to surgical findings.

Results: In the period between September 2015 and January 2016, 20 patients were recruited and underwent transperineal ultrasound imaging for the assessment of the pouch to perineum distance and the presence of fistulae. The findings were compared to pressure colostogram and/or surgical findings. The mean P-P distance between TPUS and colostogram findings correlated well with a p value of 0.462 and a strong positive Spearman’s correlation of 0.98.

In comparison to surgical findings, the TPUS was found to have a sensitivity of 85% and 100% specificity.

Conclusions: This study shows that the TPUS can be an effective tool with comparable accuracy to pressure colostogram in the clinical work up of the pediatric patient with “ARM”.