Avulsion of the puborectalis muscle is associated with asymmetry of the levator hiatus

Abstract

To determine the degree of levator hiatal asymmetry in women with unilateral avulsion of the puborectalis muscle in order to estimate the likely effect of successful reconstruction. We reviewed datasets of women seen between May 2005 and January 2009 in a tertiary urogynecological unit. Archived ultrasound volume datasets were analyzed for hiatal dimensions and puborectalis muscle trauma in patients with unilateral avulsion. From 929 eligible datasets we identified 71 patients with isolated complete unilateral tears. Unilateral avulsion was associated with a significant increase in hiatal area (P ≤ 0.002). Relative to a hypothetical normal hiatus (intact hemi-area × 2), avulsion was associated with a larger hiatus on Valsalva maneuver (+2.1 cm(2) or 7%). Unilateral puborectalis muscle avulsion results in an asymmetric increase in the size of the levator hiatus. This increase is relatively minor, accounting for < 10% of hiatal area. Surgical repair of an avulsion may have only limited effects on hiatal dimensions.