Abstract P6-14-07: The evolving role of pre-pectoral acellular dermal matrix -assisted approach in implant-based immediate breast reconstruction following conservative mastectomy: A prospective observational study
Authors: Tayeh Salim , Chehade Hiba El Hage , Manson Aisling , Mokbel Kefah 
Published: March 2020

Abstract
Background: The recent development of acellular dermal matrix (ADM) devices has enhanced implant-based breast reconstruction (IBR) surgery following nipple-sparing mastectomy (NSM) for therapeutic and risk-reducing purposes leading to improved aesthetics. In the traditional sub-pectoral approach, coverage of the implant is provided by the pectoral muscles superiorly and the ADM inferiorly. The need to eliminate breast animation, reduce post-operative dysfunctional pain and the risk of capsular contracture, have stimulated surgeons to investigate the feasibility of placing the implant over the pectoralis major muscle with complete coverage with ADM thus introducing a novel pre-pectoral approach. The aim of this study was to evaluate the short clinical outcomes and patients’ satisfaction after NSM combined with ADM-assisted immediate IBR.
Materials and Methods: Thirty consecutive patients underwent 40 pre-pectoral ADM-assisted IBR following NSM (61% therapeutic and 39% risk-reducing). A peri-areolar incision was used in all cases. A fixed volume microtextured (Mentor) or nanotextured (Sebbin) implant was used in 32 single stage procedures (80%) and a microtextured tissue expander was used in 2-stage reconstruction in 8(20%). A fenestrated ADM (SurgiMend) was used to provide full coverage of the implant. A drain and prophylactic antibiotics and anti-thromboembolism measures were used in all cases. All patients were followed up regularly in the outpatient department and were invited to complete a bespoke satisfaction questionnaire.
Results: A total of 9 (22.5%) patients had prior radiotherapy (RT) or post-mastectomy RT (PMRT). Seventeen patients (56.7%) received adjuvant or neoadjuvant chemotherapy. The median hospital stay was 2 days (range: 2-4 days). The final surgical margins and subareolar biopsy were clear in all cases. After a median follow up of 12 months (6-24 months), we observed no cases of local recurrence, or loss of implant or nipple. There was one wound complication (2.5%). None of the patients developed grade 3/4 capsular contracture, however a significant degree of rippling of the upper pole requiring autologous fat grafting was seen in 2 cases (5%). Twenty-three patients completed the questionnaire and reported a median satisfaction score of 9 out of 10 with the unclothed appearance, 10 out of 10 with the clothed appearance and 10 out of 10 with the overall body image.
Conclusions: Our study lends further support to the growing body of evidence that pre-pectoral ADM-assisted IBR following NSM is reliable and safe. It is associated with a low incidence of capsular contracture and high patient’s satisfaction. Neither prior RT nor PMRT represent contraindications to this approach.
Citation Format: Salim Tayeh, Hiba El Hage Chehade, Aisling Manson, Kefah Mokbel. The evolving role of pre-pectoral acellular dermal matrix -assisted approach in implant-based immediate breast reconstruction following conservative mastectomy: A prospective observational study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-14-07.