Impact of Suture Materials on Surgical Site Infection in Oral Oncological Surgery With Free-Flap Reconstruction: Analysis Using Propensity Scores.

Objective: The impact of suture materials on surgical site infections (SSIs) has been well documented in various surgical fields; however, it has not been thoroughly examined in oral oncological surgery with free-flap reconstruction. This study aimed to evaluate the incidence of oral SSIs associated with the use of monofilament and braided sutures for flap fixation.

Methods: A retrospective chart review of patients who underwent oral oncological resection with free-flap reconstruction was conducted between May 2020 and April 2024. Either monofilament (4-0 PDS® II or Monodiox®) or braided (3-0 Vicryl®) suture was used for flap suturing. The primary outcome was the incidence of oral SSIs, defined according to the guidelines of the United States Centers for Disease Control and Prevention. Multivariable logistic regression and inverse probability of treatment weighting based on propensity scores were used to estimate the risk differences.

Results: Of 209 eligible patients, 58 experienced oral SSIs, resulting in an incidence of 27.8%. Monofilament sutures were used in 174 patients and braided sutures in 35. The incidence of oral SSIs was higher in the braided suture group (42.9%) than in the monofilament suture group (24.7%). Analysis using propensity scores revealed a significantly higher risk of oral SSIs associated with braided sutures than with monofilament sutures, with a 18.5% risk difference (95% confidence interval, 2.1%-34.9%; P = 0.027).

Conclusions: Braided sutures may pose an increased risk of SSIs in oral oncological surgeries with free-flap reconstructions. Monofilament sutures are recommended for reconstructions, especially of the floor of the mouth.