Postoperative Complications Following Neoadjuvant Therapy Across Different Oncoplastic Breast Surgery Techniques: A Retrospective Comparative Study in Breast Cancer Patients.

Background: Neoadjuvant therapy (NAT) is increasingly used in breast cancer to downstage tumors and expand eligibility for breast-conserving approaches. NAT may also influence tissue vascularity and wound healing capacity, potentially affecting postoperative morbidity. Oncoplastic breast surgery (OBS) improves cosmetic outcomes while maintaining oncological safety; however, the impact of specific OBS techniques on postoperative complications after NAT remains unclear. In this context, postoperative complications are clinically important as they may lead to delayed initiation of adjuvant therapy, increased hospital stay, higher morbidity, and impaired cosmetic and quality-of-life outcomes. This study aimed to evaluate the associations between different OBS techniques and postoperative complications in patients undergoing surgery after NAT. Methods: This retrospective study included patients who underwent level II OBS after NAT between 2019 and 2025. Patients were categorized into five groups according to the surgical technique: racquet; vertical; radial fusiform incision; batwing-donut-Grisotti; and J-, L-, or V-shaped mammoplasties. The primary endpoint was comparison of complication rates among techniques. Secondary endpoints included identification of factors associated with complications. Complications were graded using the Clavien-Dindo classification, and overall morbidity was assessed using the Comprehensive Complication Index (CCI). Results: A total of 556 patients were analyzed. Racquet and vertical mammoplasties were associated with significantly larger resection volumes than the other techniques. These two techniques demonstrated significantly higher rates of overall and major complications, as well as wound dehiscence, surgical site infection, and seroma (p<0.05). Clavien-Dindo grades and CCI scores were also significantly higher in the racquet and vertical mammoplasty groups. Despite these differences, reoperation rates did not differ significantly between techniques. Conclusion: Postoperative complication rates were significantly influenced by the OBS technique chosen following NAT. Racquet and vertical mammoplasties were associated with higher morbidity, likely due to larger resection volumes, altered tissue perfusion, and more extensive tissue dissection. Individualized technique selection based on tumor characteristics, breast anatomy, and patient risk factors is essential to minimize complications while preserving oncological safety and aesthetic outcomes.