Antibiotic Treatment Has No Influence on Anal Fistula Formation and Recurrent Perianal Abscess After Incision and Drainage of Cryptogenic Perianal Abscess: A Randomized Single-Blind Prospective Study.

Abstract

Anal fistula commonly appears after incision and drainage of perianal abscess. Theoretically, fistula develops as a consequence of infection process. Antibiotic treatment was suggested to decrease the possibility of fistula development. We hypothesized that antibiotic treatment has no influence on development of anal fistula after surgical treatment of perianal abscess. A single blind randomized prospective study. Patients with primary cryptogenic abscess were eligible to participate. Patients were divided in two groups. Patients in Group I received amoxicillin 875mg/clavulanic acid 125mg during 7 days after surgery and Group II patients received no antibiotics. Study database included demographics, clinical and laboratory data. Patients were examined in our outpatient clinic 2 weeks, four months and 1 year after surgery and telephone questionnaire performed 6 month after surgery. Primary Outcome was formation of anal fistula. Secondary Outcome was recurrent perianal abscess. Overall 98 patients completed the study. Groups were not different on inclusion. Anal fistula was diagnosed in 16 (16.3%) patients in Group I (treatment group) and 10 (10.2%) patients in the Group II (control group) (p = 0.67). Nine patients (9.2%) developed recurrent perianal abscess, 4 in the treatment group, and 5 in the control group (p = 0.73). Relatively small number of patients treated in single Medical Center. Antibiotic therapy has no influence on anal fistula or recurrent perianal abscess formation after incision and drainage of perianal abscess. See Video Abstract.