Objective: Endarterectomy represents a therapeutical option for patients with advanced coronary artery disease. The mid-term results are compromised by restenosis due to neointima formation. The aim of this study was to evaluate a new treatment concept - endarterectomy with consecutive gamma-irradiation - in a rat model. Methods: Male Sprague-Dawley rats underwent left carotid endarterectomy with removal of intima: control (n = 10) or were irradiated with 15 Gray (Gy) (n = 13) or 20 Gy (n = 10) postoperatively and compared with sham-operated rats (n = 10). After 3 weeks, carotid arteries were perfusion-fixed and vessel compartment areas were measured. Transmission electron microscopy and immunohistochemical staining were used to confirm neointima formation. Results: Three weeks after endarterectomy, neointimal hyperplasia was found in the control group (0.07 ± 0.04 mm2). After irradiation, a dose-dependent reduction of neointima was observed (0.003 mm2 at 15 Gy and 0.0007 mm2 at 20 Gy, P < 0.0001). However, immunohistochemical staining revealed that thin re-endothelialization after irradiation was not inhibited. Conclusions: Gamma-irradiation significantly suppressed neointimal hyperplasia in a rat model of surgical endarterectomy. Despite inhibition of intimal hyperplasia, re-endothelialization after adjuvant brachytherapy was present. Adjuvant brachytherapy may be therefore a new concept to prevent restenosis after endarterectomy in patients.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Cardiology and Cardiovascular Medicine