Cohesive Round Implants and the Risk of Implant Flipping

BACKGROUND: Fifth-generation, round, form-stable implants have a higher cohesive gel, a higher fill volume, and distinct anterior and posterior profiles. Due to these implant features, anterior-posterior (AP) flipping of round, form-stable implants is discernible, but little is known of this complication of implant reconstruction. METHODS: Patients who underwent skin- or nipple-sparing mastectomy followed by direct-to-implant reconstruction with round, cohesive, smooth implants were included in this retrospective study. Implants were placed submuscularly or prepectorally. Incidence of flipping was retrieved from patient records. Patients were stratified by presence or absence of flipping; data on patient demographic characteristics, neoadjuvant/adjuvant treatment, mastectomy characteristics, and acellular dermal matrix (ADM) type (AlloDerm or FlexHD) and coverage technique (inferior pole, tenting, or wrapping) were compared between the groups to identify risk factors associated with flipping. RESULTS: A total of 117 patients (230 breasts) were evaluated. Sixteen cases of implant flipping were documented for a flip rate of 7.0%, all occurring in patients with prepectoral implants. On univariate analysis, prepectoral implant placement, highly cohesive implants, use of AlloDerm, and ADM wrapping/tenting were found to be significantly associated with AP flipping. On logistic regression analyses, ADM type and ADM coverage technique were no longer significant predictors of AP flipping. CONCLUSIONS: Patients who undergo prepectoral implant reconstruction with highly cohesive round implants appear to be at an increased risk of AP flipping. Subpectoral reconstruction is not associated with AP flipping.