The Recipient Venule in Supermicrosurgical Lymphaticovenular Anastomosis: Flow Dynamic Classification and Correlation with Surgical Outcomes

Background Venules have been usually neglected in the literature on lymphaticovenular anastomosis (LVA). The aim of this study was to analyze the flow dynamic of recipient venules in LVA and their impact on the surgical outcomes. Patients and Methods Data from 128 patients affected by extremity lymphedema, who underwent LVA, were collected in two institutions from August 2014 to May 2016. Recipient venules were classified according to their flow dynamic into backflow, slack, and outlet (BSO classification). Quantitative (lower extremity lymphedema/upper extremity lymphedema index) and qualitative outcomes (needing of compression garment and compression garment class) were evaluated. Chi-square test or Fisher's exact test was used for categorical variables and independent-samples t -test for continuous variables. The association between lymphatic collector degeneration status (normal, ectasis, contractile, sclerotic type [NECST]) and BSO classification with the outcomes was analyzed by the Mantel–Haenszel test. Results On a total of 128 patients, 37 suffered from upper and 91 from lower limb lymphedema. An average number of four LVA were performed for each patient (range: 2–8). A significant association was observed between NECST and BSO categories and the outcomes were evaluated. Patients with contractile and sclerotic collectors had 2.24 times the odd of having poor composite outcome compared with those with normal-to-ectasis collectors ( p < 0.05). Patients with backflow venules had 3.32 times the odd of having poor composite outcome compared with those without outlet or slack pattern ( p < 0.05). Conclusion The subtype of recipient venule flow dynamic has a significant impact on the surgical outcome of patients undergoing LVA for the treatment of lymphedema, regardless of the lymphatic collector degeneration status. Locating favorable venules in the preoperative mapping might enhance the surgical outcomes.