UC Irvine

Background

Although interest in sphincter-sparing treatments for anal fistulas is increasing, few large prospective studies of these approaches have been conducted.

Objective

The study assessed outcomes after implantation of a synthetic bioabsorbable anal fistula plug.

Design

A prospective, multicenter investigation was performed.

Setting

The study was conducted at 11 colon and rectal centers.

Patients

Ninety-three patients (71 men; mean age, 47 years) with complex cryptoglandular transsphincteric anal fistulas were enrolled. Exclusion criteria included Crohn's disease, an active infection, a multitract fistula, and an immunocompromised status.

Intervention

Draining setons were used at the surgeon's discretion. Patients had follow-up evaluations at 1, 3, 6, and 12 months postoperatively.

Main outcome measures

The primary end point was healing of the fistula, defined as drainage cessation plus closure of the external opening, at 6 and 12 months. Secondary end points were fecal continence, duration of drainage from the fistula, pain, and adverse events during follow-up.

Results

Thirteen patients were lost to follow-up and 21 were withdrawn, primarily to undergo an alternative treatment. The fistula healing rates at 6 and 12 months were 41% (95% CI, 30%-52%; total n = 74) and 49% (95% CI, 38%-61%; total n = 73). Half the patients in whom a previous treatment failed had healing. By 6 months, the mean Wexner score had improved significantly (p = 0.0003). By 12 months, 93% of patients had no or minimal pain. Adverse events included 11 infections/abscesses, 2 new fistulas, and 8 total and 5 partial plug extrusions. The fistula healed in 3 patients with a partial extrusion.

Limitations

The study was nonrandomized and had relatively high rates of loss to follow-up.

Conclusion

Implantation of a synthetic bioabsorbable fistula plug is a reasonably efficacious treatment for complex transsphincteric anal fistulas, especially given the simplicity and low morbidity of the procedure.