D5. Differentiating Transient Fluid Retention from True Lymphedema: A Novel Perspective after LYMPHA with Axillary Surgery in Breast Cancer Survivors

PURPOSE: Lymphedema is concerning post-axillary surgery. Temporary immobility causes reversible bioimpedance spectroscopy (BIS) changes within six months, distinct from permanent lymphedema. We introduce "Transient fluid retention," which resolves within a year. METHODS: Retrospective study with breast cancer patients undergoing axillary dissection with LYMPHA (Lymphatic Microsurgical Preventing Healing Approach) (February 2021- June 2022). L-DEX(BIS) outside the normal range (±10 L-DEX unit) or ≥10 L-DEX unit increase above the baseline was abnormal. RESULTS: 46 patients; mean age 51.4 years, mean BMI 27.57 kg/m2. Of 7 patients with an abnormal L-DEX within first 6 months, 5 (71.4%) had normal L-DEX at 12 months. Of 16 patients with abnormal L-DEX at any time, 14 (87.5%) resolved after 12 months. Patients with abnormal L-DEX within 3 months were twice more likely to resolve by 12 months. 92.85% of patients with abnormal L-DEX received radiation. Patients with lymphedema had higher number of nodes resected. CONCLUSION: Most (71.4%) increases in L-DEX in first 6 postoperative months resolved. Developing an increased L-DEX earlier in the postoperative period increases the likelihood of resolution.