BACKGROUND: Silicone leakage from breast implants is a concern with potential implications for patient health. This study aimed to quantify and model silicone leakage from implants to the breast implant capsule and to investigate whether silicone cohesiveness affected the silicone leakage rate.

METHODS: Silicone content in the breast implant capsule was quantified histologically by measuring the area of silicone deposits. This was used to model silicone leakage over time based on the time of implantation. The effect of cohesiveness on silicone leakage was investigated across all implant brands with declared cohesiveness and in a subanalysis comparing only Mentor cohesive I implants with cohesive II and III implants.

RESULTS: The study included 493 patients with 872 breasts and a median time of implantation of 13.0 years (range 0.4 to 51 years). The modeling of silicone leakage from intact implants showed that leakage and the acceleration of the leakage rate were significantly higher in low-cohesive implants than in highly cohesive implants (p<0.05). This was confirmed when analyzing only Mentor implants (p<0.05) and in the case of implant rupture (p<0.01) where low-cohesive implants also leaked significantly more than highly cohesive implants.

CONCLUSIONS: Our results suggest that highly cohesive implants are superior to low-cohesive implants in preventing silicone leakage. Due to the accelerating rate of silicone leakage especially found in low-cohesive implants, we propose that exchange of low-cohesive implants could be discussed with patients 10 to 15 years after implantation to minimize silicone leakage even in the absence of implant rupture.