PURPOSE: Implant malposition is a common reason for revisionary surgery in prosthetic breast reconstruction. A multitude of techniques has been described for correction of implant malposition, but few studies have examined risk factors for malposition and no studies to date have directly compared the use of acellular dermal matrix (ADM) and synthetic mesh for correction of implant malposition. We endeavored to identify risk factors for malposition location and compare outcomes by repair technique.
METHODS: Retrospective review of a single surgeon series of implant reconstruction was performed. Variables of interest included age, body mass index (BMI), radiation history, implant size, implant malposition with need for capsulorrhaphy procedure, location of malposition (inferior or lateral), and technique (suture, ADM, or mesh). Binary logistic regression analysis was performed to identify risk factors for implant malposition. Analysis of variance testing was performed to compare success rates by capsulorrhaphy location and technique.
RESULTS: Of 836 breasts, 82 (9.8%) exhibited implant malposition. Risk factors for any malposition were older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.02–1.07), BMI <25 (OR, 1.64; 95% CI, 1.00–2.70), and bilateral reconstruction (OR, 13.41; 95% CI, 8.50–21.16). Risk factors for inferior malposition were similarly older age (OR, 1.04; 95% CI, 1.01–1.06), BMI <25 (OR, 3.43; 95% CI, 1.88–6.26), and bilateral reconstructions (OR, 11.50; 95% CI, 6.79–19.49), whereas risk factors for lateral malposition were only older age (OR, 1.05; 95% CI, 1.02–1.08) and bilateral reconstructions (OR, 7.08; 95% CI, 4.09–12.26). Postmastectomy radiation was protective against lateral malposition (OR, 0.30; 95% CI, 0.10–0.88). Implant malposition rates were highest at the extremes of implant volume to BMI ratios (both high implant volume to BMI and low implant volume to BMI). A zone of intermediate implant volume to BMI ratios was identified with significantly lower risk of malposition (1.3% versus 11.2%; P = 0.007). Fifty-eight breasts underwent capsulorrhaphy with ADM (n = 28) or synthetic mesh (n = 35). Sixteen breasts (27.9%) required redo capsulorrhaphy. Capsulorrhaphy failure was more common in ADM compared to mesh repairs (50.0% versus 5.7%; P < 0.001). Older age and ADM use were risk factors for capsulorrhaphy failure (OR, 1.21; 95% CI, 1.03–1.43; and OR, 62.2; 95% CI, 3.24–1,193.84, respectively).
CONCLUSION: This study identifies risk factors for implant malposition after prosthetic breast reconstruction and represents the first direct comparison of ADM versus synthetic mesh for capsulorrhaphy. Risk factors for implant malposition vary by malposition location. Lower BMI increases risk for inferior malposition while radiation is protective against lateral malposition. Regarding repair technique, ADM has higher failure rates compared to synthetic mesh when used for correction of implant malposition in prosthetic breast reconstruction.