Predicting venous congestion before DIEP breast reconstruction by identifying atypical venous connections on preoperative CTA imaging.

Venous congestion is the principle cause of flap failure after microsurgical breast reconstruction. We aim to correlate preoperative computed tomography angiography (CTA) findings with postoperative venous congestion to predict patients at risk of congestion. All patients undergoing deep inferior epigastric perforator (DIEP) breast reconstruction between August 2009 and August 2013 underwent preoperative CTA and prospectively entered the study. Patients with postoperative venous congestion were matched with a similar cohort of complication-free patients. Preoperative CTAs were randomized and re-interpreted by a radiologist, blinded to the subsequent clinical outcome. Inter-group comparisons were performed. Two hundred and forty DIEP flaps were performed in 202 patients over the 4-year study. Venous congestion affected 15 flaps (6.3%). Preoperative CTA showed significantly more atypical venous connections between deep and superficial systems in congested flaps compared to controls (66.7% vs. 8%; P < .0001), with a positive predictive value of 83%. Atypical connections were narrow, tortuous, or incomplete. Patients with congestion-free flaps had more normal connections (80% vs. 26.7%; P < .001) and more cranial perforators (P = .02). Similar CTA findings between groups included perforator size and lateral position, superficial inferior epigastric vein size, crossing of midline, and absent connections (P > .05). Preoperative CTA identifies atypical venous connections between deep and superficial systems that increase the risk of postoperative DIEP congestion five-fold. Identifying atypical venous connections maximizes the chances of flap survival and minimizes complications for patients considering DIEP breast reconstruction.