Treatment of Complicated Anal Fistula by an Endofistular Polyurethane-Sponge Vacuum Therapy: A Pilot Study.

Background: Treatment of supra- and transsphincteric anal fistulas remains a clinical challenge because current treatment results are variable and potentially endanger sphincter function.

Objective: Based on positive results of endoluminal polyurethane-sponge vacuum therapy in the upper and lower GI tract, a new system for endofistular vacuum therapy was developed for anal fistulas to utilize vacuum therapy to remove the endofistular pseudoepithelium and to induce granulation in the fistula tract.

Design: This study is based on a prospective case series.

Patients: Seven patients with complicated anal fistulas (3 associated with Crohn's disease and 4 of cryptoglandular origin) longer than 4 cm were treated. Initially, the fistula was curettaged and the first endofistular vacuum therapy sponge was positioned in the fistula tract. The inner fistula opening was closed by suture. A 125 mm Hg constant vacuum was applied to the sponge, and the endofistular vacuum therapy sponge was changed a median of 3 (3-5) times after each 48 to 72 hours of constant vacuum therapy. After final removal, the fistulas were reevaluated every other week for 3 months.

Main Outcome Measure: The main outcome measured was the closure of the fistula.

Results: All patients tolerated the therapy well and no adverse events were observed. Fistula tract closure was demonstrated within 4 weeks after the termination of vacuum therapy. One patient with cryptoglandular fistula developed a recurrence within the follow-up of 3 months.

Limitations: This was an observational study that had no control arm.

Conclusion: In this pilot case series, the results are encouraging. Because endoluminal vacuum therapy would be a new and sphincter-sparing therapy, this concept warrants further investigation in controlled trials.