Limitations of Computed Tomography Angiography in Preoperative Planning of Peroneus Brevis Rotational Flap

Background: The distally based peroneus brevis (PB) rotational flap has been shown to be a reliable method of coverage of distal third tibial wounds. The flap is perfused via retrograde flow from distal PB perforators located within 8 cm of the lateral malleolus. The ability to assess patency of these vessels preoperatively facilitates surgical planning, and computed tomography angiography (CTA) has been used for perforator assessment of other lower extremity flaps. The purpose of the present study is to establish the potential utility of standard CTA for locating distal PB perforators by examining uninjured lower extremities. Methods: Twenty-five patients who underwent bilateral lower extremity CTAs using standard lower extremity protocol were retrospectively identified. Axial two-dimensional images were scanned craniocaudally using our institution's standard CT image viewing software, Merge Radsuite (Merge Healthcare, Hartland, Wis.). Results: The average location of distal-most PB perforators identified on CT angiogram was 13.1 ± 5.1 cm proximal to the distal fibula, or 34.5% ± 13.5% of total fibular length. Standard CTA was only able to locate a pedicle within 8 cm of the lateral malleolus (20.9% of fibular length) in three of 25 patients (12%). Conclusions: Previous studies have described a reliable pedicle within 8 cm of the distal fibular tip upon which to design a distally based PB rotational flap. The absence of such perforators in the CT angiogram suggests that standard CT angiogram is not a reliable technique for identifying the patency of such perforators when evaluating the utility of a distally based PB flap.