Risk Factors for Anteroposterior Implant Malposition in Postmastectomy Patients with Cohesive Round Implants

Abstract

BACKGROUND: Round cohesive implants are increasingly popular due to their ability to maintain shape, higher fill volume, and projection. However, they have also been associated with a higher risk of implant flipping. The current literature on risk factors of anteroposterior implant malposition in patients with two-stage implant-based reconstruction (IBR) is scarce. We identified predisposing factors of implant anteroposterior malposition in postmastectomy patients with prepectoral round, cohesive, smooth implants. METHODS: A retrospective review of patients who underwent postmastectomy two-stage IBR with prepectoral Natrelle Inspira Cohesivity Level 3 implants, from 2013 to 2020 at our institution, was conducted. Inclusion criterion was patients 18 years or older who had a prepectoral tissue expander and prepectoral breast implant. Patients who had prior breast reconstruction or aesthetic surgeries were excluded. RESULTS: A total of 214 implants (84.9% bilateral) in 106 patients were included. The mean age at surgery was 51.1 ± 11.4 years, and the mean body mass index was 27.0 ± 4.8 kg/m2. In total, 22.35% had a history of radiation to the chest wall, and 46.3% had chemotherapy. Of all breasts, 79.4% had prior MX tissue expanders, the median implant volume was 485 cm3 (Q1-3: 385–580), and acellular dermal matrix was placed in 65.4% of breasts. Anteroposterior malposition was reported in 19 (8.9%) breasts, 50% of which underwent surgery to correct the flipping. The mean time to implant flipping was 6.1 months (Q1-3: 3.5–16.8), and the mean follow-up time was 12.2 months (5.0–17.5). On univariate analysis, SCX implants [OR= 3.4 (1.3–8.7), P = 0.01], implant volume > 400 cm3 [OR 8.9 (1.2–68.2), P = 0.011], older age at surgery (OR = 1.1 P = 0.022), and BMI (OR=1.1, P = 0.005) were correlated with a higher risk of anteroposterior malposition. CONCLUSIONS: Use of SCX implants, implants with a volume > 400 cm3, older age at surgery, and high BMI increase the risk of anteroposterior malposition in Natrelle Inspira Cohesivity Level 3 implants. These results can be useful for patient counseling, better surgical planning, and improving clinical practice.