Incidence and Risk Factors for Postoperative Complications in Patients Undergoing Extraoral Drainage for Maxillofacial Abscess: A Retrospective Cohort Study

Background: The standard treatment for maxillofacial abscesses is surgical drainage combined with antibiotics, a frequent procedure in maxillofacial surgery departments. However, postoperative complications following this surgery are poorly described in the literature. Identifying their incidence and risk factors could help improve patient outcomes and healthcare planning. Objectives: The primary aim was to identify postoperative complications within 30 days after maxillofacial abscess surgery; the secondary aim was to explore their associated risk factors. Methods: A monocentric retrospective cohort study included patients with maxillofacial abscesses who underwent extraoral incision and drainage under general anesthesia at the Department of Cranio-Maxillofacial and Oral Surgery at a tertiary hospital in Switzerland between January 2012 and August 2023. Postoperative complications within 30 days were recorded and classified according to the validated Dindo–Clavien classification system. Univariable and multivariable logistic regression analyses were conducted to identify risk factors for postoperative complications. Results: A total of 253 participants were analyzed. The overall complication rate was 24.1%, with 15.8% major complications (Dindo–Clavien grade ≥3). The most common minor complications (Dindo–Clavien grade <3) were hypokalemia and lower-extremity edema, with an incidence of 6.4%. The most common major complications were persistent and recurrent abscesses, with an incidence rate of 10.4%. These complications occurred in the early (median range 1–5 days) and delayed (median range 14–15 days) postoperative courses, respectively. Overall, the mortality rate was 0.4%. On multivariable analysis, an American Society of Anesthesiologists (ASA) score >2 was associated with overall and major postoperative complications (odds ratio [OR], 3.38; 95% CI 1.75–6.51; p < 0.001 and OR, 3.76; 95% CI 1.83–7.72; p < 0.001, respectively). Additionally, female sex (OR, 1.97; 95% CI 1.05–3.70; p = 0.036) and C-reactive protein level >50 mg/L (OR, 2.25; 95% CI 1.01–4.98; p = 0.046) were associated with overall postoperative complications. Conclusions: This study introduces a novel application of the Dindo–Clavien classification to maxillofacial abscess surgery, providing a standardized framework for assessing postoperative complication severity. Through this approach, we identified ASA score >2, female sex, and CRP level >50 mg/L as risk factors for postoperative complications. Our findings highlight the importance of close monitoring during the first five postoperative days to detect early complications, such as persistent abscesses, and recommend standardized outpatient follow-up for at least two weeks to identify delayed complications, like recurrence.