Anal fistula height: is the proportion of sphincteric muscle involved really useful?

We read with interest the paper by Kolodziejczack on the accuracy of three dimensional endoanal ultrasound in determining the height of anal fistula compared to the intraoperative finding. High fistulas (> 30% involvement of sphincter lenght) were identified by ultrasound with high accuracy (92%)(1).In the literature nearly all studies assess the height of the fistula as the proportion of involved sphincter complex. Fistulas involving >30% of the sphincter lenght are usually classified as high(2). Several authors reported different rate cut-off of involved sphincter (25%-50%-66%-75%) to identify the amount of sphincter muscle that can be divided without continence impairement (2,3). This article is protected by copyright. All rights reserved