Implant-based breast reconstruction—a systematic review and meta-analysis of prepectoral versus submuscular implant placement

This is the authors' abstract. We don't add key points for this paper.

Background: Implant based breast reconstruction began in the 1970s. Over the ensuing decades, the placement of silicone breast implants has varied from underneath a muscular chest wall coverage to a subcutaneous location. With the advent of the incorporation of dermal matrix as a component of breast reconstruction, along with more cohesive gel implants, there has been renewed enthusiasm for pre-pectoral (subcutaneous) implant placement. Pre-pectoral reconstruction has the advantage of not detaching the pectoralis muscle from the sternum and ribs, thereby using the same plane of dissection as the mastectomy for reconstruction. In this fashion, there is considerably less pain and many of the procedures, including immediate reconstruction, can be performed on an outpatient basis. The purpose of this research was to perform a meta-analysis of the literature comparing the two planes of reconstruction for risks of complications and outcomes. Methods: A comprehensive literature review was completed on PubMed, Ovid, and MEDLINE databases using the key search “prepectoral OR pre pectoral AND submuscular OR dual plane OR subpectoral OR sub pectoral AND breast reconstruction”. The search was completed on the seventeenth of July in 2024. Cochrane’s Collaboration tool for assessing risk-of-bias was also conducted on the included studies. Results: Out of the total of 824 studies that resulted from this search, 47 studies met criteria of directly comparing outcomes between pre-pectoral and sub-pectoral (total or partial) implant-based breast reconstruction and were included in this study. Pre-pectoral cohort had statistically higher rates of seroma than the sub-pectoral counterpart [odds ratio (OR): 1.41, 95% confidence interval (CI): 1.08–1.85]. Rippling was seen at higher rates in the pre-pectoral group (OR: 2.21, 95% CI: 1.52–3.21). The submuscular group was found to have higher rates of animation deformity (OR: 0.09, 95% CI: 0.03–0.25). There was no significant difference in hematoma, infection, wound healing, flap/nipple necrosis, implant exposure, explantation, capsular contracture, implant malposition or readmission rates. Conclusions: Pre-pectoral implant-based reconstruction has a similar risk profile to sub-pectoral reconstruction, especially in the setting of acellular dermal matrices. Surgeons can confidently utilize either reconstructive plane to best fit the patient and mastectomy flap needs. However, there is a higher expected rate of rippling and seroma formation with prepectoral implants, while there is a higher rate of animation deformity with submuscular implantation. Therefore, the choice of location of the implant may depend on these findings, as well as other factors that could not be determined from this study, such as, thickness of skin flaps, size of implant, number of stages for reconstruction and surgeon experience.