Lymphedema refers to edema caused by insufficient drainage of interstitial fluid through the lymphatic circulation system. It occurs mainly in the upper and lower extremities and causes chronic inflammation, and finally fibrous adipose tissue is replaced. In this study, the'LYMPHA' (Lymphatic microsurgical preventing healing approach) procedure, which connects lymphatic vessels drained from the arm to the side branches of the axillary vein, contributes to the prevention of lymphedema in patients undergoing axillary lymph node dissection for breast cancer. Investigator aim to help patients' quality of life by prospectively analyzing the effects and applying them to clinical practice, reducing the incidence of lymphedema.

Patients in the LYMPHA group undergo Axillary reverse mapping before the start of surgery, and after axillary lymph node resection, LYMPHA procedure is performed in which the lymphatic vessels drained from the arm and the axillary vein are micro-bonded to the side branches.

Inclusion Criteria:

1. Age over 19 years old
2. Patients who are expected to undergo surgery under the diagnosis of breast cancer, and are determined to undergo axillary lymph node dissection before surgery.

Exclusion Criteria:

1. Patients with vascular and lymph-related diseases
2. Patients with a history of surgical treatment or trauma to both arms and axillary
3. Patients with a history of receiving radiation treatment in both arms, chest, and axilla
4. Patients with confirmed systemic metastasis with stage 4 breast cancer
5. Pregnant and lactating patients

Female patient