Lymphovenous Coupler-Assisted Bypass (CAB) for Immediate Lymphatic Reconstruction.

BACKGROUND: Breast cancer-related lymphedema is the most common cause of lymphedema in the United States and occurs in up to 50% of individuals receiving axillary lymph node dissection (ALND). Lymphovenous bypass (LVB) at the time of ALND may prevent lymphedema, but long-term results and anastomotic patency are unclear. This study evaluates the feasibility and outcomes of performing immediate lymphatic reconstruction via coupler-assisted bypass (CAB).

METHODS: This is a retrospective review of all patients undergoing prophylactic LVB following ALND at two tertiary care centers between 2018-2022. Patients were divided into cohorts based on whether they received the 'standard' end-to-end (E-E) suturing or CAB technique. The primary outcome of interest was development of lymphedema. Quantitative and qualitative assessments for lymphedema were performed preoperatively and at 3, 6, 12, and 24 months postoperatively.

RESULTS: Overall, 63 lymphovenous bypasses were performed, of which 24 lymphatics underwent immediate reconstruction via "CAB" and 39 lymphatics via "standard" end-to-end suture. Patient characteristics, including BMI, and treatment characteristics, including radiation therapy, did not significantly differ between groups. CAB was associated with a greater mean number of lymphatics bypassed per vein (standard 1.7 vs. CAB 2.6 p=0.0001) and bypass to larger veins (standard 1.2 vs. CAB 2.2 mm, p<0.0001). At a median follow-up of 14.7 months, 9.1% (1/11) of individuals receiving CAB developed lymphedema. These rates were similar to those seen following standard bypass at 4.8% (1/21), although within a significantly shorter follow-up duration (standard 7.8 vs. CAB 14.7 months, p=0.0170).

CONCLUSION: The CAB technique is a viable, effective technical alternative to the standard LVB technique. This comparative study of techniques in prophylactic LVB suggests that coupler-assisted bypasses maintain long-term patency, possibly due to the ease of anastomosing several lymphatics to single large caliber veins while reducing the technical demands of the procedure.