Routine Preoperative CT Scanning of Patients with Anorectal Sepsis is not Useful. A Retrospective Cohort Study

Abstract Background: The use of preoperative imaging in anorectal abscesses (AA) is still debated. It is customary to treat AA based solely on clinical findings. Several short- and long-term sequelae of AA have been described such as abscess persistence, recurrence, and anal fistula formation. The current literature does not clarify whether additional preoperative imaging is beneficial. Objectives: This study aims to investigate whether performing a preoperative computed tomography (CT) scan influences the outcome after drainage and AA recurrence. Design: Retrospective cohort study. Settings: Patient files. Patients (Materials) and Methods: All consecutive patients undergoing AA drainage between January 2015 and January 2020 were studied retrospectively. The patients who underwent a preoperative computed tomography (preCTI) were compared to those without preoperative imaging (noCTI). Main Outcome Measures: Abscess persistence requiring re-intervention and AA recurrence. Sample size: Two-hundred and nineteen patients were included in this study. Results: Preoperative CT scans were performed in 93 patients. The median length of stay was 1 day. The overall median follow-up duration was 56 days. Male and obese patients were more likely to undergo preoperative CT scans. There was no difference in re-intervention for abscess persistence or recurrence. More drains were placed in the preCTI group ( P = .0001), and postoperative antibiotics were administered more often ( P = .0008) in this group. Conclusion: Routine preoperative CT imaging in acute anorectal sepsis has no benefit in terms of outcomes, namely abscess persistence or recurrence after 30 days. In the preCTI group, an additional drain was placed in a greater number of cases, and postoperative antibiotics were administered more frequently.