Abstract 65: Immediate Lymphatic Reconstruction After Axillary Lymphadenectomy Makes A Difference: A Two Year Comparative Analysis

Abstract

Purpose: Axillary lymph node dissection (ALND) in the treatment of breast cancer increases the risk of iatrogenic lymphedema. Current rates after ALND range from 11-30%. We hypothesize that our lymphedema prevention surgical (LPS) paradigm, ALND with axillary reverse mapping (ARM) and lymphatico-venous bypass (LVB), lowers the risk of lymphedema. Here, we present findings from a case control study from patients undergoing this procedure. Methods: A review of our prospectively maintained lymphedema surgical registry was performed. Ninety-six consecutive patients with complete ALND underwent LPS at our institution from 9/2016-10/2019. A control group was selected consisting of 92 patients who underwent ALND without LPS in a concurrent time interval from 9/2016-11/2017 to prevent surgical technique or learning curve bias. Patients were followed for both signs and symptoms of lymphedema throughout the post treatment interval and underwent serial assessments for lymphedema via standardized arm circumference measurements by a certified lymphedema therapist. Lymphedema was defined as more than a 10% difference in volume between upper limbs in conjunction with characteristic symptoms and signs. Demographic, procedural and oncologic data was compared between groups. Results: Lymphedema occurrence rates were significantly different between control and treatment groups during the followup period (16.3% non-LPS vs. 5.3% LPS, p=0.006). Of the 15 non-LPS patients who developed lymphedema, 14 received PMRT and 5 had neoadjuvant chemotherapy. Five LPS patients acquired lymphedema, two had PMRT and all five underwent neoadjuvant chemotherapy. Clinical staging differed with a higher proportion of advanced nodal stage in LPS patient group. The mean lymph nodes removed per case was slightly higher in the LPS group (14.4 vs. 11.2). Rates of post mastectomy radiation therapy (PMRT) were similar (77% to 89%, respectively), but neoadjuvant chemotherapy rates were lower in non-LPS patients (43% vs 74%). The follow-up time was 15.3 months for the LPS group and 31.3 months for the non-LPS group. Following reverse mapping in LPS, an average of 2.1 blue transected lymphatics were identified per case. An average of 0.1 blue lymphatic vessels was left in continuity per case and 1.6 vessel anastomoses performed per case with intussusception being performed more frequently than end to end technique (55% vs 44%). Conclusion: In one of the largest controlled studies in this topic to date, our findings support that optimizing lymphatic preservation and restoring antegrade lymphatic flow with LPS significantly decreases short term lymphedema rates in patients undergoing axillary lymphadenectomy for breast cancer.