BackgroundAxillary lymph node dissection (ALND) in breast cancer patients is infamous for its accompanying morbidity. Selective preservation of upper extremity lymphatic drainage and accompanying lymph nodes crossing the axillary basin - currently resected during a standard ALND - has been proposed as a valuable surgical refinement. MethodsPeroperative Axillary Reversed Mapping (ARM) was used for selective preservation of upper extremity lymphatic drainage. A multicentre patient- and assessor-blinded randomized study was performed in clinical node negative, sentinel node positive early breast cancer patients. Patients were randomized to undergo either standard-ALND or ARM-ALND. Primary outcome was the presence of surgery-related lymphedema at six, 12 and 24 months post-operatively. Secondary outcomes included patient reported and objective signs and symptoms of lymphedema, pain, paraesthesia, numbness, loss of shoulder mobility, quality of life and axillary recurrence risk. ResultsNo significant differences were found between both groups using the water displacement method with respect to measured lymphedema. ARM-ALND resulted in less reported complaints of lymphedema at six, 12 and 24 months postoperatively (p < 0.05). No axillary recurrence was found in both groups. ConclusionsIn contrast to results of volumetric measurement, patient reported outcomes support selective sparing of the upper extremity lymphatic drainage using ARM as valuable surgical refinement in case of ALND in clinically node negative, sentinel node positive early breast cancer. If completion ALND in clinically node negative, sentinel node positive early breast cancer is considered, selective sparing of upper extremity axillary lymphatics by implementing ARM should be carried out in order to reduce morbidity.