Optimal Dual Antiplatelet Therapy Duration For Carotid Artery Stenting On the Basis of Angioscopic Findings

Dual antiplatelet therapy plays a crucial role in preventing thrombosis in the perioperative period of carotid artery stenting (CAS); however, it has been associated with a risk of hemorrhagic complications. A standard regimen for the duration and combination of antiplatelet therapy is yet to be established. Angioscopy enables direct visualization of neointimal coverage and might help determine the optimal duration of dual antiplatelet therapy through the assessment of post-CAS neointimal coverage.

This prospective study enrolled 20 patients who were scheduled to undergo CAS at the Osaka Police Hospital. A 2-month post-CAS period was chosen for angioscopic neointima evaluation on the basis of previous evidence of reliable neointimal coverage 2 months following coronary artety stenting. Furthermore, antiplatelet therapy was initiated 1 week before CAS and continued until angioscopic examination. Angioscopic evaluation categorized the degree of neointimal coverage and was supplemented with carotid ultrasonography and biplane angiography.

Coincidentally, a dual-layer stent was used in all cases. The stent lumen was observed in 19 of the 20 cases. One case was difficult to evaluate owing to poor visibility. Angioscopy showed complete neointimal coverage in 18 of 19 cases and partial coverage in 1 case. Ultrasonography could detect neointima in 9 of 20 cases, and angiography showed a radiolucent gap suggestive of neointima in all cases in which neointima was confirmed via angioscopy. No post-CAS or procedural complications occurred.

Angioscopy performed 2 months following CAS revealed large neointimal coverage, suggesting that a 2-month duration of dual antiplatelet therapy is generally sufficient. However, as a limitation, this study was performed using the same dual-layer stent; thus, additional studies with other stents are required.