Abstract P5-16-06: Prepectoral versus retropectoral implant-based breast reconstruction - The surgical and radiotherapeutical perspective
Authors: Deutschmann C , Gschwantler-Kaulich D , Dorffner G , Singer C , Leser C , Kauer-Dorner D 
Published: May 2019

Abstract
Background: Subpectoral implant positioning has been the standard of care in breast reconstruction despite involving disadvantages owing to the detachment of the pectoralis major muscle such as disruption of the muscle function, animation deformities and prolonged postoperative pain. Refined ablative techniques as well as dermal matrices and synthetic mesh products have led to the reintroduction of subcutaneous implant-based breast reconstruction possibly avoiding the negative sequelae of pectoralis disinsertion.
Objective: The primary objective of this study was to compare procedure-related complication rates following prepectoral versus retropectoral implant-based breast reconstruction. Furthermore the effect of the implant position on the quality of post-mastectomy radiation therapy (PMRT) was analysed.
Methods: All patients who underwent an implant-based breast reconstruction after mastectomy at the Department of Obstetrics and Gynecology of the University Clinic of Vienna within the years 1.1.2013 to 31.12.2017 were included in the study. A retrospective chart review of the patients was conducted assessing parameters regarding the mastectomy, the reconstruction, complications following the reconstructive procedure, patient-associated risk factors and radiation treatment plans. Complication rates were analysed one week, one month and one year after the implant-based reconstructive operation.
Results: In total 57 patients (94 breasts) were reconstructed following a prepectoral implant-placement approach, 95 patients (149 breasts) were reconstructed with implants in a retropectoral position. The two patient cohorts did not differ significantly in the occurrence of complications including the following dehiscence, infection, seroma, secondary bleeding, necrosis, fistula, capsular contracture and rippling. No significant differences regarding reinterventions and reoperations including seroma drainage, secondary suture and reoperation following secondary hemorrhage and necrosis could be detected between the two study populations. The two surgical procedures were not associated with a different rate of implant loss.
12 (2 in the cohort of patients with prepectorally placed implants and 10 in the subgroup of patients with subpectorally positioned implants) out of 152 patients needed PMRT for oncological safety. Prepectoral versus retropectoral implant positioning did not affect breast Dmean or D90, heart Dmax or V5 or lung V20 across treatment plans.
Conclusion: The study demonstrated no inferior outcome regarding the occurrence of complications, reinterventions, reoperations and implant loss of prepectoral implant-based breast reconstruction compared to retropectoral implant positioning. Therefore, subcutaneous implant placement permits reconstruction of the breast with comparable procedure-related complication rates while avoiding disadvantages associated with the detachment of the pectoral muscle.
Regarding the radiation perspective both prepectoral and retropectoral implant positioning allow for optimal coverage of the chest wall with acceptable doses to the heart and lung.
Citation Format: Deutschmann C, Gschwantler-Kaulich D, Dorffner G, Singer C, Leser C, Kauer-Dorner D. Prepectoral versus retropectoral implant-based breast reconstruction - The surgical and radiotherapeutical perspective [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-16-06.