The Deciding Factors of Flow Direction in Lymphovenous Anastomosis for Extremity Lymphedema.

BACKGROUND: While using lymphovenous anastomosis (LVA) to treat extremity lymphedema, an antegrade lymphatic-to-venous flow is usually considered to indicate a functional and effective anastomosis. The authors analyzed the characteristics of lymphovenous anastomoses in patients with extremity lymphedema to look for the deciding factors of the flow direction. METHODS: A total of 45 patients (15 arms and 42 legs) undergoing LVA for extremity lymphedema were reviewed. Only the anastomoses with intraoperatively confirmed patent flow or clear visualization of vessel lumens during anastomosis were included for analysis. Multivariate logistic regression was used to identify the contributing factors of intraoperative washout phenomenon or venous reflux. RESULTS: A total of 105 eligible LVAs were included for analysis. Anastomosis with a more sclerotic lymphatic duct is statistically significantly associated with more venous reflux (OR, 2.82; P = 0.003). Larger diameter difference between lymphatic duct and recipient vein (OR, 12.8; P = 0.02) and less sclerotic lymphatic duct (OR, 0.47; P = 0.03) are statistically significantly associated with more washout phenomena. CONCLUSIONS: The deciding factors of flow direction in LVA are difference of diameters between lymphatic duct and recipient vein, and the severity of lymphosclerosis. To obtain favorable antegrade lymph-to-vein flow, a less sclerotic lymphatic duct with larger diameter and a recipient vein with smaller diameter should be chosen for anastomosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.