Concordance between preoperative imaging methods in patients with limb lymphedema undergoing supermicrosurgical lymphaticovenular anastomosis

Objective: Supermicrosurgical lymphaticovenular anastomosis (LVA) is increasingly being recognized as a first-line treatment for limb lymphedema because it is minimally invasive and highly effective. Lymphoscintigraphy and indocyanine green (ICG) lymphography are the two most commonly performed diagnostic imaging examinations to establish the indication and plan the procedure in patients affected by limb lymphedema. In a small group of patients, the information between these two imaging tools can be discordant, showing different anatomical drainage pathways or showing absence of drainage and dermal backflow in one examination, and valid drainage pathways in the other. The purpose of this study is to examine the types of possible discrepancies between lymphoscintigraphy of the superficial system and ICG lymphography, and to describe the surgical outcome after LVA in patients presenting such discrepancies. Methods: We retrospectively reviewed the data of all patients who underwent LVA for upper or lower limb lymphedema between July 2015 and July 2023. From this series, we identified a group of patients who had non-concordant imaging results from lymphoscintigraphy and ICG-L prior to lymphatic surgery. Non-concordant findings were described in terms of "pattern discordance" or "pathway discordance". Surgical outcome was measured by the change in mean circumference of the limb after surgery. The changes between preoperative and postoperative limbs' measures were analyzed by Student's t-test. P values<0.05 were considered significant. Results: A total of 28 patients with limb lymphedema exhibited inconsistencies between preoperative lymphoscintigraphy of the superficial system and ICG lymphography. Among these patients, 14 experienced "pattern discordance", while 13 had "pathway discordance", and 1 patient had both. After LVA, we observed a significant reduction in the average circumference of the affected limb in the analyzed group. Conclusions: The discrepancy of information between lymphoscintigraphy and ICG lymphography in the preoperative study of patients affected by limb lymphedema is rare but possible. This phenomenon is still not fully explained, but our results suggest that it does not correlate with the outcome of supermicrosurgical lymphovenous anastomoses.