Does antibiotic therapy prevent fistula in-ano after incision and drainage of simple perianal abscess?

Does antibiotic therapy prevent fistula in-ano after incision and drainage of simple perianal abscess?

Can J Surg 2020;63(4):E362-E364 | PDF

Mantaj S. Brar, MD; Feza Remzi, MD; Janindra Warusavitarne, BMed, PhD*; Indraneel Datta, MD, MSc; for the Evidence Based Reviews in Surgery Group

Key points about the article

Background: The development of a perianal fistula following incision and drainage of a perianal abscess is common and leads to a significant burden of symptoms for patients and the need for further surgical intervention.

Study objective: To assess the role of postoperative antibiotics in the prevention of fistula in-ano after incision and drainage of perianal abscess.

Methods: The authors conducted a randomized single-blind clinical trial in which patients were assigned to either 7 days of oral metronidazole and ciprofloxacin in addition to standard care or to standard care alone without any antibiotics after discharge from the hospital.

Results: Patients in the antibiotics group (n = 155) had significantly lower rates of fistula formation than those in the group that received standard care alone (n = 144, p < 0.001). Both univariate and regression analyses indicated that postoperative antibiotics had a protective role against fistula formation.

Conclusion: The authors conclude that postoperative antibiotics play an important role in preventing fistula development and advise a 7- to 10-day course of postoperative antibiotics. Given the short-term follow-up in this study, it is unclear whether routine antibiotic administrations will decrease fistula formation in the long term.

*J. Warusavitarne is the external expert reviewer of this manuscript.

Accepted Mar. 17, 2020

Affiliations: From the Department of Surgery, St. Paul’s Hospital, Vancouver, BC (Raval, Morris); and the Department of Surgery, University of Rochester Medical Center, Rochester, New York (Temple).

Competing interests: None declared.

Contributors: All authors contributed substantially to the conception, writing and revision of this article and approved the final version for publication.

Members of the Evidence Based Reviews in Surgery Group: Chad G. Ball, Nancy N. Baxter, Mantaj Brar, Carl J. Brown, Prosanto K. Chaudhury, Indraneel Datta, Sandra de Montbrun, Justin Dimick, Elijah Dixon, G. William N. Fitzgerald, Samantha Hendren, Lillian S. Kao, Andrew Kirkpatrick, Steven Latosinsky, Robin S. McLeod, Arden M. Morris, Jason Park, Timothy M. Pawlik, Manoj Raval, Kjetil Soreide, Malin Sund, Larissa Temple, Bas Wijnhoven, Desmond Winter.

DOI: 10.1503/cjs.017119

Correspondence to: I. Datta, Department of Surgery and Oncology, Cumming School of Medicine, University of Calgary, 1004 8 Ave SE, Calgary AB T2G 0M4,