For many high anal fistulas, lay open is still a good option

Optimal treatment for high/complex anal fistulas is uncertain. We have studied one surgeon's results over a ten-year period, concentrating on high fistulas.

Demographic, fistula anatomy and treatment data were recorded for all patients undergoing surgery for anal fistula. Outcome data were recorded for patients who had been followed up for a minimum of 4 weeks.

One hundred and eighty patients were studied. Outcome data were available for 52 low and 84 high fistulas. Fistulotomy was performed for 50 low and 48 high fistulas, with closure rates of 98 and 96%, respectively. There was fistula recurrence in two patients with high fistulas. Symptoms of sphincter disturbance were similar after lay open of low and high fistulas. Treatment of a high fistula by drainage seton had a lower rate of inadvertent passage of flatus but a similar rate of minor soiling compared with fistulotomy.

Lay open of low and high anal fistulas is effective and associated with a similar, predictable rate of minor sphincter disturbance, amounting to a third to one quarter of patients with mild leakage of flatus and mucus. Patients with high fistulas can be cured, but when a surgeon is in doubt, a second opinion at an expert centre should be sought before definitive intervention.