Does rectal mucosal blood flow affect the outcome of transanal advancement flap repair?

Transanal advancement flap repair provides a useful tool for the treatment of high transsphincteric fistulas. Recent studies indicate that transanal advancement flap repair fails in one of every three patients. Until now no definite risk factors for failure have been identified. A previous pilot study, conducted in our own institution, revealed a significant decrease in rectal mucosal blood flow after creation of the advancement flap. We postulated that impaired blood flow might result in breakdown of the distal part of the flap. This study was designed to evaluate the effect of rectal mucosal blood flow on the outcome of transanal advancement flap repair.

Between August 2004 and June 2007 a series of 54 patients with a high transsphincteric fistula underwent transanal advancement flap repair. The present series comprised 34 males and 20 females. Median age at the time of repair was 45 (range, 25-68) years. Rectal mucosal blood flow was determined by laser Doppler flowmetry before and after creation of the flap. The flow was expressed in arbitrary units.

Transanal advancement flap repair was successful in 34 patients (63%). Median healing time was 2.2 months. Median mucosal blood flow before and after transanal advancement flap repair was 145 arbitrary units and 94 arbitrary units, respectively. This decrease was statistically significant. In a comparison of patients with and patients without a successful repair, no differences were found in mucosal blood flow before and after creation of the flap (146 vs. 138 arbitrary units and 83 vs. 104 arbitrary units).

Rectal mucosal blood flow does not affect the outcome of transanal advancement flap repair.