Time-dependent factors in DIEP flap breast reconstruction

Background: The process of harvesting and performing microsurgical anastomosis may lengthen deep inferior epigastric artery perforator (DIEP) flap breast reconstruction affecting results and patient safety. The aim of the study was to investigate the associations between predictors and operative time (OT). METHODS: Between 2004 and 2016, 336 immediate and 68 delayed unilateral reconstructions were performed in 404 patients. Age, weight, height, body mass index (BMI), nulliparity, or pluriparity condition were collected to determine the impact of patient characteristics on OT. Flap weight, mastectomy type, flap zone, perforator number, venous anastomoses, recipient vessels selection, reconstruction timing, contralateral symmetrization, and a dedicated anesthesiologist were analyzed as possible predictors. RESULTS: Mean OT was 289 min (range, 150-550 min). Using univariate analysis, for each increment of BMI value and patient weight OT increased, respectively, 3.5- and 1.4 min (97.5% CI: 1.768-5.145, 97.5% CI: 0.739-1.949; P < 0.001). Skin-sparing mastectomy (SSM) (97.5% CI: 2.487-36.637; P = 0.025), perforator number, and venous anastomoses (97.5% CI: 24.468-43.690, 97.5% CI: 24.843-50.492; P < 0.001) negatively influenced OT while nipple-sparing mastectomy (NSM) reduced OT of 22.7-min (97.5% CI: -40.333 to -5.098; P = 0.012). The use of circumflex scapular vessels as recipients reduced OT of 75.4-min while internal mammary vessels (IMV) increased OT of 55.8-min (97.5% CI: -88.631 to -62.209, 97.5% CI: 22.918-88.642; P < 0.001). A dedicated anesthesiologist and the learning curve (LC) reduced OT, respectively, of 39.63-min and of 13-min for every year (97.5% CI: -57.119 to -22.137, 97.5% CI: -14.666 to -11.898; P < 0.001). Using multivariate regression, LC was a negative predictor while SSM, perforators number, superficial epigastric vein, IMV, and flap weight were positive predictors (P < 0.001). CONCLUSIONS: The increase of flap weight, related perforators number, and venous drainage negatively influence OT. LC meaning systematic approach for surgery can optimize DIEP flap surgery efficiency.