LAUSR

Background: The lymph system plays important roles in maintaining fluid balances, the immune system, and lipid metabolism. After tissue replantation or transfer, some cases suffer long-lasting edema or lymphedema caused by interruption of main lymph flows; however, this mechanism has yet to be clarified. Methods: The medical charts of 38 patients who underwent indocyanine green lymphography after tissue replantation or free flap transfer were reviewed to obtain data regarding clinical demographics, intraoperative findings, and postoperative indocyanine green lymphographic findings. Postoperative lymph flow restoration based on indocyanine green lymphographic findings was evaluated according to intraoperative findings, including raw surface in lymph axiality and compatible lymph axiality. Results: Lymph flow restoration was observed in 24 cases (63 percent). There were significant differences in positive lymph flow restoration with regard to sex (male, 78 percent; female, 40 percent; p = 0.017), cause of defect (trauma, 83 percent; others, 33 percent; p = 0.002), type of operation (replantation, 94 percent; free flap, 41 percent; p = 0.001), and compatible lymph axiality (positive, 96 percent; negative, 0 percent; p < 0.001). Based on lymph axiality, the raw surface in lymph axiality–negative and compatible lymph axiality–positive condition was completely matched with lymph flow restoration positivity; 100 percent accuracy to predict postoperative lymph flow restoration was observed. Conclusions: Lymph flow can be restored after tissue replantation or free flap transfer without lymph node or supermicrosurgical lymphatic anastomosis. The raw surface in lymph axiality–negative and compatible lymph axiality–positive condition is considered a key for restoring lymph flows after surgery affecting the main lymph pathway. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.