Silicone Particles in Breast Implant Capsules: A Prospective Unicentric Study Evaluation of Silicone Particle Bleeding

Goals/Purpose: The placement of breast implants is one of the most common surgical procedures in the field of plastic surgery. Although these medical devices are considered safe by the FDA, their use is not free of complications. One of these complications is silicone particle bleeding, or the migration of silicone particles from the breast implant into the peri-prosthetic capsule. These particles represent a potential source of chronic inflammation localized around breast implants. Little is known about the presence of these silicone particles and their long-term potential consequences on patient health. The primary objective of this study is to quantify the silicone particles present in the peri-prosthetic capsules of different types of breast implants. This data will preclude the study of risk factors for silicone bleeding and elucidate the silicone exposure levels patients undergo over time.

Methods/Technique: This study is a single-center prospective study, carried out at the Centre Hospitaller de l'Université de Montréal (CHUM) between May 2021 and June 2022. The patients included in this study were all adults undergoing surgical revision of their breast implants for reasons of asymmetry, breast ptosis, capsular contracture, or a personal desire to remove them from apprehension of developing breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). The patient demographic data were collected as well as the size and type of the implants (saline or silicone gel) and the duration for which they remained in place. During the revision surgery, several capsule samples were collected and sent to the pathology department of the CHUM to be processed and prepared on histological slides. These were then digitized with the NanoZoomer Digital Pathology scanner and then viewed using the NDP.view2 software. In each capsule sample, we: (1) manually counted each silicone particle, (2) measured the average particle size, (3) measured the surface area of the capsule and (4) estimated the particle density of silicone in each capsule sample. The average particle density of each samples allowed us to determine what was the approximate number of silicone particles in the entire peri-prosthetic capsule of the implant.

Results/Complications: A total of thirty peri-prosthetic capsules were retrieved and analyzed. Among them, twenty came from silicone implants and ten from saline implants. 85% of capsules analyzed from silicone gel implants contained silicone, with an average of 62 particles per mm³ of capsular tissue. These patients had approximately 1 million silicone particles per capsule. In contrast, none of the saline implant capsules contained silicone. Moreover, the capsular thickness of the silicone gel implants was significantly greater than that of the saline implants (540 µm vs 312 µm; p = 0.012).

Conclusion: In this small cohort of patients, the majority of the silicone gel implants presented with silicone particle bleeding into the peri-prosthetic capsule, totaling on average 1 million silicone particles per capsule. On the other hand, no silicone particle bleeding was observed with the use of saline breast implants. This data suggests that particle bleeding comes from the inner silicone gel, and not from the outer silicone shell. Additionally, capsular thickness of the silicone breast implants is significantly higher than that of the saline implants. Future and larger-scale studies are necessary to determine clinical significance.