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

BACKGROUND: Fistulotomy plus primary sphincteroplasty for complex anal fistulas\r\nis regarded with scepticism, mainly because of the risk of postoperative\r\nincontinence.\r\nOBJECTIVES: The aim of this study was to evaluate safety and effectiveness of\r\nthis technique in medium-term follow up and to identify potential predictive\r\nfactors of success and postoperative continence impairment.\r\nDESIGN AND SETTING: This was a prospective observational study conducted at a\r\ntertiary care university hospital in Italy.\r\nPATIENTS: A total of 72 patients with complex anal fistula of cryptoglandular\r\norigin underwent fistulotomy and end-to-end primary sphincteroplasty; patients\r\nwere followed up at 1 week, 1 and 3 months, 1 year, and were invited to\r\nparticipate in a recent follow-up session.\r\nMAIN OUTCOME MEASURES: Success regarding healing of the fistula was assessed with\r\n3-dimensional endoanal ultrasound and clinical evaluation. Continence status was \r\nevaluated using the Cleveland Clinic fecal incontinence score and by patient\r\nreport of post-defecation soiling.\r\nRESULTS: Of the 72 patients, 12 (16.7%) had recurrent fistulas and 29 patients\r\n(40.3%) had undergone seton drainage before definitive surgery. At a mean\r\nfollow-up of 29.4 (SD, 23.7; range, 6-91 months, the success rate of treatment\r\nwas 95.8% (69 patients). Fistula recurrence was observed in 3 patients at a mean \r\nof 17.3 (SD, 10.3; range, 6-26) months of follow-up. Cleveland Clinic fecal\r\nincontinence score did not change significantly (p = 0.16). Eight patients (11.6%\r\nof those with no baseline incontinence) reported de novo postdefecation soiling. \r\nNone of the investigated factors was a significant predictor of success. Patients\r\nwith recurrent fistula after previous fistula surgery had a 5-fold increased\r\nprobability of having impaired continence (relative risk = 5.00, 95% CI,\r\n1.45-17.27, p = 0.02).\r\nLIMITATIONS: The study was limited by potential single-institution bias, lack of \r\nanorectal manometry, and lack of quality of life assessment.\r\nCONCLUSIONS: Fistulotomy with end-to-end primary sphincteroplasty can be\r\nconsidered to be an effective therapeutic option for the treatment of complex\r\nanal fistulas, with low morbidity, a high rate of success even at long-term\r\nfollow-up, and a very low rate of postoperative major fecal incontinence,\r\nalthough minor impairment of continence (postdefecation soiling) may occur.\r\nCaution should be used in selecting patients with a history of recurrent fistula \r\nand fecal incontinence.