Efferent Lymphaticovenular Anastomosis for Pelvic and Lower Extremity Lymphedema after Gynecologic Cancer Treatment: Indication and Timing Criteria Based on Nodal Function

Efferent lymphaticovenular anastomosis (ELVA) uses efferent lymphatic vessels from inguinal lymph nodes, which receive multiple afferent inputs from the lower extremity, to drain substantial lymphatic fluid. However, nodal degeneration during disease progression may impair function and affect ELVA efficacy. This study evaluated ELVA outcomes for lower extremity and pelvic lymphedema based on the presence or absence of nodal degeneration.This retrospective study included 30 patients who underwent LVA using the ELVA technique for pelvic and lower extremity lymphedema (LEL) following gynecological cancer treatment. Preoperative ultrasonography was performed to assess the vascularity of the inguinal lymph nodes. Patients with preserved nodal vascularity were classified into the primary ELVA group and underwent ELVA as the initial treatment. Those without detectable vascular flow were initially treated with leg LVA; ELVA was subsequently performed once the vascularity of the inguinal nodes improved. Treatment efficacy was evaluated based on changes in pelvic and leg volume indices.Based on preoperative ultrasonography, seven patients were classified into the primary ELVA group and 23 into the secondary ELVA group. Preoperative ICG lymphography revealed significantly lower severity in the primary group (<i>p</i> < 0.01). The mean postoperative follow-up period was 31.5 months. Significant volume reductions were observed in leg and pelvic regions, with LEL index reduced from 275.1 ± 33.8 to 247.8 ± 28.2 (<i>p</i> < 0.01), and pelvic lymphedema index from 1,053.2 ± 81.2 to 972.7 ± 76.5 (<i>p</i> < 0.01). No significant differences in volume reduction were found between the two groups.ELVA may be effective for both pelvic and LEL, even in advanced cases when performed after nodal function recovery.