Angiotensin-Converting Enzyme Inhibitor Reduces Radiation-Induced Periprosthetic Capsular Fibrosis

Area of Science:

• Biomedical Engineering
• Plastic Surgery
• Radiation Oncology

Background:

• Capsular contracture is a significant complication following radiotherapy in patients with implant-based reconstruction.
• Radiation exposure can lead to fibrosis around medical implants, negatively impacting outcomes.

Purpose of the Study:

• To evaluate the efficacy of ramipril in preventing radiation-induced fibrosis and capsular contracture around silicone implants.
• To assess ramipril's impact on key fibrotic markers and matrix metalloproteinase activity.

Main Methods:

• A Wistar rat model was used with silicone implants and radiation exposure.
• Ramipril treatment was administered pre- and post-surgery.
• Histological and immunohistochemical analyses assessed fibrosis, TGF-β1, MMP-2, and TIMP-2 expression.

Main Results:

• Radiation significantly increased capsular thickness, fibrosis, and TGF-β1 levels, while decreasing the MMP-2/TIMP-2 ratio.
• Ramipril treatment significantly reduced capsular thickness, fibrosis, and TGF-β1 positivity.
• Ramipril administration notably improved fibrotic markers in the radiation-exposed group.

Conclusions:

• Ramipril demonstrates efficacy in mitigating radiation-induced fibrosis and contracture around silicone implants.
• These findings support further clinical trials to investigate ramipril's therapeutic potential in humans for this complication.
• Ramipril presents a promising, cost-effective, and well-tolerated option for preventing post-radiation implant complications.