The impact of pre-existing venous pathology on lower limb free flap reconstruction and the role of preoperative screening: a systematic review.

Lower limb reconstruction is performed to replace like with like and achieve tissue durability. Free flaps are a method of reconstruction commonly used to manage cases of lower limb deficits. However, the failure rate is 8.5%, with venous thrombosis and congestion playing a significant role. Despite this, preoperative venous mapping of recipient site before free flap reconstruction is not routinely practiced, often resulting in pathologies remaining unidentified until the intraoperative stage. The aim of the review was to evaluate the existing literature on the topic of lower limb preoperative venous assessment, screening, and its effect on lower limb free flap survival. Five different databases were searched from their inception to August 2021. The search terms and included studies were independently reviewed by two investigators for their eligibility. Eleven articles were eligible for inclusion, with a combined patient population of 99, and 107 flaps were identified to have lower limb pathology at the donor or recipient vein. Venous pathology was detected preoperatively in 69 veins using ultrasound duplex scanning and computed tomography angiography; of them, 3 (4.34%) resulted in failure. In comparison, 38 veins were diagnosed with venous pathology intraoperatively; of them, 5 (13.85%) failed. The studies evaluated in this review demonstrated that preoperative screening for venous pathology showed a higher flap survival rate. It can therefore be inferred that developing a standardized preoperative process for identifying venous issues in lower limb free flap reconstruction may improve outcomes. This can be explored in future research, with a focus on assessing the validity and efficacy of such screening tools, and their role in the management of patients identified with venous pathology.