Predictive role of lymphoscintigraphy undergoing lymphovenous anastomosis in patients with lower extremity lymphedema: a preliminary study

BACKGROUND: We investigated whether preoperative lymphoscintigraphy could predict the treatment response of unilateral lymphovenous anastomosis (LVA) in patients with lower extremity lymphedema. MATERIALS AND METHODS: A total of 17 patients undergoing lymphoscintigraphy subsequent to LVA was included. As qualitative lymphoscintigraphic indicators, ilioinguinal lymph node uptake, main lymphatic vessel, collateral vessel, and four types of dermal backflow patterns (absent; distal only; proximal only; whole lower limb) were evaluated. Lymph node uptake ratio, extremity uptake ratio, and injection site clearance ratio were obtained as quantitative lymphoscintigraphic indicators at 1 and 2-h after injection. To evaluate therapy response, the volume difference ratio of the whole lower limb at 3 months (early response) and 1 year (late response) was measured. Volume difference ratios (continuous variable and binary variable with a cut-off value of zero) were compared according to the lymphoscintigraphic variables. RESULTS: The group with whole lower limb dermal backflow had a greater volume change than the other groups (p = 0.047). The group with dermal backflow in the whole lower limb OR only in the distal part had a higher rate of volume reduction than the group with dermal backflow only in the proximal part OR absent (p = 0.050). The 2-h extremity uptake ratio was the only indicator that positively correlated with early and late volume difference ratio (p = 0.016, p = 0.001). The rate of volume decrease at 1 year was high in patients with high 2-h extremity uptake ratio (p = 0.027). As the amount of dermal backflow increases, the postoperative therapeutic effect increases (p = 0.040). CONCLUSIONS: Preoperative lymphoscintigraphy is useful to predict both early and late therapy response in patients with lower extremity lymphedema undergoing LVA. Both dermal backflow pattern and extremity uptake ratio may be predictive lymphoscintigraphic indicators.