Fistulotomy with end-to-end primary sphincteroplasty for anal fistula: results from a prospective study.

BACKGROUND

Fistulotomy plus primary sphincteroplasty for complex anal fistulas is regarded with scepticism, mainly because of the risk of postoperative incontinence.

OBJECTIVES

The aim of this study was to evaluate safety and effectiveness of this technique in medium-term follow up and to identify potential predictive factors of success and postoperative continence impairment.

DESIGN AND

SETTING

This was a prospective observational study conducted at a tertiary care university hospital in Italy.

PATIENTS: A total of 72 patients with complex anal fistula of cryptoglandular origin underwent fistulotomy and end-to-end primary sphincteroplasty; patients were followed up at 1 week, 1 and 3 months, 1 year, and were invited to participate in a recent follow-up session.

MAIN OUTCOME MEASURES: Success regarding healing of the fistula was assessed with 3-dimensional endoanal ultrasound and clinical evaluation. Continence status was evaluated using the Cleveland Clinic fecal incontinence score and by patient report of post-defecation soiling.

RESULTS

Of the 72 patients, 12 (16.7%) had recurrent fistulas and 29 patients (40.3%) had undergone seton drainage before definitive surgery. At a mean follow-up of 29.4 (SD, 23.7; range, 6-91 months, the success rate of treatment was 95.8% (69 patients). Fistula recurrence was observed in 3 patients at a mean of 17.3 (SD, 10.3; range, 6-26) months of follow-up. Cleveland Clinic fecal incontinence score did not change significantly (p = 0.16). Eight patients (11.6% of those with no baseline incontinence) reported de novo postdefecation soiling. None of the investigated factors was a significant predictor of success. Patients with recurrent fistula after previous fistula surgery had a 5-fold increased probability of having impaired continence (relative risk = 5.00, 95% CI, 1.45-17.27, p = 0.02).

LIMITATIONS: The study was limited by potential single-institution bias, lack of anorectal manometry, and lack of quality of life assessment.

CONCLUSIONS

Fistulotomy with end-to-end primary sphincteroplasty can be considered to be an effective therapeutic option for the treatment of complex anal fistulas, with low morbidity, a high rate of success even at long-term follow-up, and a very low rate of postoperative major fecal incontinence, although minor impairment of continence (postdefecation soiling) may occur. Caution should be used in selecting patients with a history of recurrent fistula and fecal incontinence.