Exposure to toluenediamines from polyurethane-covered breast implants

Area of Science:

• Biomaterials Science
• Toxicology
• Medical Device Research

Background:

• Polyurethane (PU) breast prostheses are widely used medical devices.
• Concerns exist regarding the potential degradation of PU materials and the release of constituent chemicals.
• Toluenediamines (TDA) are known degradation products of PU.

Purpose of the Study:

• To quantify TDA levels in biological samples following PU breast prosthesis implantation.
• To investigate the long-term release kinetics and binding of TDA in patients.
• To compare TDA exposure levels to those from occupational settings.

Main Methods:

• Monitoring TDA concentrations in blood (plasma), urine, and surgical drainage (redon drains).
• Utilizing acid hydrolysis to assess TDA binding to plasma proteins.
• Longitudinal sampling up to two years post-implantation.

Main Results:

• TDA levels in redon drainage showed an initial rapid decrease followed by a plateau, indicating continuous PU degradation.
• Urinary TDA metabolite levels remained elevated above baseline throughout the study.
• Plasma TDA levels exhibited a 20-30 day lag phase before rising significantly and persisting for up to two years, with TDA found to be covalently bound to plasma proteins.

Conclusions:

• Polyurethane breast prostheses can lead to sustained systemic exposure to Toluenediamines.
• The observed TDA levels in plasma and urine are comparable to those from occupational exposure to toluene diisocyanate.
• These findings highlight the importance of long-term monitoring for TDA exposure in patients with PU breast implants.