Early experience using optical coherence tomography for intraluminal evaluation of vascular healing associated with endovascular treatment of intracranial aneurysms

OBJECTIVE The aim of the study was to observe the intraluminal characteristics of flow diverter devices and neurovascular stents immediately after placement using optical coherence tomography (OCT), with a focus on the presence of intrastent thrombosis and device apposition to the vascular wall. Additionally, the authors describe the postimplantation evolution, particularly vascular remodeling (neoendothelialization), aneurysm closure, and patency of the side branches. METHODS Intravascular OCT evaluations were performed 9 different times in 5 aneurysms treated via endovascular techniques in 5 female patients (median age 32.8 years). All patients were randomly selected and were on a daily regimen of dual antiplatelet therapy (acetylsalicylic acid at 100 mg and clopidogrel at 75 mg). Key findings included apposition, intrastent thrombus, neointima formation (neoendothelialization), aneurysm neck closure, and patency of the side branches. RESULTS OCT assessments were successfully completed in all cases. The cohort included 1 patient with a posterior circulation aneurysm treated with a stent and coils and 4 patients with anterior circulation aneurysms treated with flow diverters. No procedure-related complications were observed, and all cases showed proper device apposition without evidence of intrastent thrombosis. However, intrasaccular thrombosis occurred in 3 patients, with fibrin mesh and thrombus formation identified on the surface of the stent or flow diverter. Successful closure was achieved for all aneurysms, with satisfactory neointima formation and preserved patency of the side branches. CONCLUSIONS Intravascular OCT was a feasible method to visualize the vascular remodeling process during treatment of intracranial aneurysms. It also provides a valuable decision-making tool by clearly highlighting potential complications, such as malapposition, intrastent thrombosis, or excessive endothelialization leading to stenosis. This study represents the second reported series using intravascular OCT in patients with intracranial aneurysms, and it includes the largest cohort to date. Further studies are needed to validate the utility of OCT in the neurovascular field, and development of dedicated OCT devices for intracranial navigation is essential.