Prolonged operative time is a risk factor for adverse postoperative outcomes in the unilateral deep inferior epigastric perforator (DIEP) flap surgery: A retrospective cohort study

Abstract

Currently, one published study documented operative time (OT) as a predictor for postoperative outcomes in bilateral deep inferior epigastric perforator (DIEP) flap breast reconstructions. No literature has investigated this in unilateral DIEP flaps. We aimed to determine the relationship between unilateral OT, postoperative complications, unplanned reoperations (UR), and extended length-of-stay (eLOS). Patients who underwent elective unilateral DIEP reconstruction from 2018 to 2023 at a tertiary centre in London, United Kingdom, were retrospectively analysed. Patients were divided into four groups depending on OT quartiles to define a critical cut-off period. Data on extensive covariates, including procedural complexity, was recorded and used in univariable and multivariable regression models. The final cohort contained 173 patients. After risk-adjustment, ≥421-minute operations led to a significantly higher overall complication rate (HR: 2.14, 95% CI: 1.26, 3.64, p=0.005) relative to <421min. Significantly higher odds of eLOS were observed in the ≥460-minute group (OR: 2.07, 95% CI: 1.07, 3.99, p=0.03) compared to <460min. There was no significant effect on the rate of postoperative UR across any OT group. We confirmed OT was an independent predictor for postoperative outcomes in the DIEP flap, and demonstrated this in unilateral reconstructions. A clinical maximum threshold of 7h was derived based on this cohort to help guide future surgical practice. Efficiency can be achieved by meticulous preoperative planning and process standardisation, multiple senior surgeons working per flap, and smooth teamwork between specialities and intraoperative staff.