Prospective randomized trial of drainage alone vs drainage and fistulotomy for acute perianal abscesses with proven internal opening

PURPOSE: Incision and drainage (I & D) with concurrent or delayed fistulotomy is the usual treatment for abscess-fistula with a demonstrated internal opening. We compared incision and drainage alone vs. with concurrent fistulotomy for perianal abscesses with a demonstrated internal opening. METHODS: Consecutive patients with acute perianal abscesses and a demonstrated internal opening were prospectively randomized into either the I & D group or drainage with concurrent fistulotomy group. They were followed up at one month, three months, and one year. RESULTS: The I & D group had 21 patients, and the fistulotomy group had 24 patients. Thirteen patients had low intersphincteric abscess-fistula, and seven had low transsphincteric fistulas in the I & D group. The fistulotomy group had 9 intersphincteric abscess-fistula compared with 14 low transsphincteric ones. Median duration of surgery, hospital stay, and continence at final follow-up were the same in the two groups. Three had recurrent abscess-fistula in the I & D group compared with none in the fistulotomy group (P = 0.09). CONCLUSION: I & D alone for acute anal abscess-fistula with demonstrated internal opening showed a tendency to recurrence that did not reach a statistically significant difference compared with concurrent fistulotomy. I & D, therefore, puts only a few patients at risk for recurrence.