Abstract： Objective To compare the effects of different axillary lymph node surgical procedures on complications following immediate two-stage breast reconstruction after mastectomy.Methods A retrospective analysis was performed on 232 patients who underwent mas-tectomy with immediate two-stage breast reconstruction in the Department of Breast Surgery at the First Hospital of China Medical Uni-versity between January 2018 and December 2021.Patients were divided into two groups based on the type of axillary lymph node surgery performed:the sentinel lymph node biopsy group(SLNB group,n=84)and the axillary lymph node dissection group(ALND group,n=148).We compared baseline characteristics,surgical procedures,and postoperative complications between the two groups.Results The ALND group had a higher prevalence of advanced T and N stages,received neoadjuvant chemotherapy more frequently,and underwent chemotherapy and radiotherapy at a higher rate compared to the SLNB group.Additionally,the ALND group experienced greater drainage volume and a significantly higher complication rate(all P<0.05).Postoperative infection was the most common complication observed in the ALND group.Importantly,no significant differences were found in long-term outcomes(local/regional recurrence,distant metastasis,and disease-free survival)between the two groups(all P>0.05).Conclusion In patients undergoing immediate two-stage breast recon-struction after mastectomy,axillary lymph node dissection is associated with a higher rate of reconstruction complications compared to sentinel lymph node biopsy.