The Utility of Preoperative Venous Testing for Lower Extremity Flap Planning in Patients with Lower Extremity Wounds

Background: Although venous thrombosis is a leading cause of flap failure, the majority of lower extremity free flap planning is centered on arterial system evaluation. Preoperative identification of relevant abnormality in lower extremity venous systems by means of duplex ultrasound may aid in the diagnosis of clinically important abnormality that could affect lower extremity flap outcomes. Methods: Between November of 2014 and August of 2017, 57 patients underwent preoperative lower extremity venous duplex imaging and free tissue transfer for lower extremity wounds. A retrospective review was performed to describe lower extremity venous pathologic findings, relevant patient demographic data, comorbid conditions, and outcomes. Discovery of venous abnormality helped guide recipient vein selection. Results: Fifty-seven consecutive patients underwent 59 free flap operations to treat chronic lower extremity wounds. Venous duplex ultrasonography detected venous insufficiency (defined as >0.5 second of reflux) in 23 patients (39.0 percent), including 16 (27.2 percent) with deep thigh reflux, six (10.2 percent) with superficial calf reflux, and four (6.78 percent) with deep calf reflux. Deep venous thrombosis was found in four patients (6.78 percent) and treated with anticoagulation. The flap success rate was 98.3 percent. Five patients (8.47 percent) progressed to amputation. At a mean follow-up time of 15.1 ± 9.51 months (range, 1.67 to 35.2 months), 53 patients (89.8 percent) were able to continue community ambulation. Conclusions: Lower extremity venous duplex testing before free tissue transfer may be useful for optimizing flap recipient vessel selection and for detecting potentially unknown venous abnormality. Development of free flap planning protocols incorporating preoperative vascular imaging is important to achieving good functional outcomes in this comorbid patient population. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.