[Preoperative computed tomographic angiography and perforator flaps: a standardization of the protocol]

Perforator flaps have an increasing role in reconstructive surgery. The preoperative analysis of perforator arteries enables the precise identification of their caliber and course, and so to select the optimal one(s), in order to improve the flap's design therefore reducing operating time. This study aims to propose a standardized protocol of computed tomographic angiography (CTA) before DIEAP flap, ALT flap, TAP flap and SGAP flap.

This study focuses on CTA before conducting a perforator flap. Together with radiologists, a CTA protocol has been developed. It specifies the patient's positioning, the intravenous contrast's concentration, flow rate, acquisition start and slice thickness as well as techniques used for mapping and 3D reconstruction.

Patient positioning must be the same as the operating positioning during acquisition. His skin should be free of any cloth, clothing or bandages. The intravenous contrast must have a concentration between 350 and 400mg/ml for a flow rate of 4 ml/sec and its injection followed by a rinçure with 30 ml of saline water. The region of interest (ROI) should be defined for each flap. Its definition makes it to follow the contrast's progression through it. Acquisition begins when the contrast bolus arrives at the ROI. Slice thickness should be of 0.625 mm.

CTA gives information on the caliber and the septal or intramuscular course of perforator as well as on its source vessel. By making a mapping of perforators, it prepares surgical procedure and dissection. The CTA protocol enhances reliability of perforator flaps.