Predicting venous insufficiency in flaps raised on the deep inferior epigastric system using computed tomography (CT) angiography.

Computed Tomography Angiogram (CTA) has become a routine part of pre-operative assessment of vascular anatomy and design in perforator flaps. We conducted a retrospective cohort study of flap raised on the deep inferior epigastric system (DIES) at our institution in order to identify CTA signs that might predict venous congestion in these flaps. 98 consecutive patients who had 124 DIES flaps raised from 2008 to 2012 were studied. Of these 124 flaps, four (3.2%) developed venous congestion. Our results showed that a Superficial Inferior Epigastric Vein (SIEV) that is larger than the DIEV at origin is highly predictive of congestion (5.2 vs 3.5 mm, p = 0.007). The findings of an axial non-arborising superficial system (96.7% vs 0, p < 0.001), without connection to deep system perforators (38.1 vs 88.8%, p < 0.001) and a type I pedicle were also predictive (75 vs 64.2%, p = 0.22). These results show the importance of CTAs as a pre-operative study for the identification of risk factors for venous compromise, and their use should prompt a robust discussion of the risk of flap failure with patients, and contingency planning to augment venous drainage with the superficial system if required.