Preclinical Direct Endoluminal Assessment of Endothelialization After Flow Diversion With Microangioscopy

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Vascular Surgery

Background:

• Direct endoluminal imaging, including microangioscopy, is an emerging tool for managing endovascular cerebral aneurysms.
• It allows high-resolution visualization of thrombi and neoepithelialization post-stent placement.

Purpose of the Study:

• To evaluate flow diversion in vivo using direct endoluminal imaging.
• To validate microangioscopy findings with histopathology.

Main Methods:

• A rabbit model was used, implanting shielded and non-shielded flow diverters (FDs) in carotid arteries.
• Animals were divided into three groups based on antiplatelet therapy: none, aspirin, or aspirin plus clopidogrel.
• Outcomes including FD thrombosis, stenosis, malapposition, and neoepithelialization were assessed via angiography and microangioscopy at 30 days.

Main Results:

• No significant differences in thrombosis, stenosis, malapposition, or neoepithelialization were observed between shielded and non-shielded FDs in treated groups.
• Group 1 (no antiplatelet therapy) showed significantly more thrombus formation.
• Microangioscopy measurements of neointimal thickness strongly correlated with histological findings (r=0.72, P=0.016).

Conclusions:

• Shielded and non-shielded flow diverters demonstrated comparable safety and efficacy in vivo.
• Microangioscopy is a valuable adjunct for assessing neointimal thickness and FD performance, correlating well with histopathology.