Reassessment of non-acute occlusion in intracranial flow diverter implantation: an animal experimental study based on optical coherence tomography, intravascular ultrasound, and pathological correlation
10.3760/cma.j.cn113694-20240813-00551
- VernacularTitle:颅内血流导向装置非急性闭塞再认识：一项基于光学相干断层扫描、血管内超声和病理对照的动物实验研究
- Author:
Zhuangzhuang WEI
1
;
Qi TIAN
;
Shuailong SHI
;
Jie YANG
;
Ji MA
;
Zhen LI
;
Haiqiang SANG
;
Yi TANG
;
Yuncai RAN
;
Yong ZHANG
;
Baohong WEN
;
Shanshan XIE
;
Jinjuan CHEN
;
Enjie LIU
;
Xinwei HAN
;
Tengfei LI
Author Information
1. 郑州大学第一附属医院放射介入科 郑州大学介入治疗研究所，郑州450052
- Publication Type:Journal Article
- Keywords:
Swine;
Carotid artery, internal;
Graft occlusion, vascular;
Tomography, optical coherence;
Ultrasonography, interventional;
Models, animal
- From:
Chinese Journal of Neurology
2025;58(6):607-614
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate and summarize the imaging and pathological features of non-acute occlusion following flow diverter (FD) implantation in animal models.Methods:Four experimental pigs (experimental group) that experienced non-acute occlusion (occlusion time exceeding 24 hours) within the FD stent implanted in the common carotid artery, and 19 pigs (control group) that did not experience stent occlusion during the same period were involved. Using an interventional approach under digital subtraction angiography (DSA), the 4 occluded FD lumens were mechanically opened. Optical coherence tomography (OCT), intravascular ultrasound (IVUS) and histopathological examinations were performed to evaluate the intraluminal composition and characteristics of the occlusive tissues. These findings were compared with non-occluded FD stents to summarize the imaging and pathological changes within the occluded FD lumen.Results:The occlusion times of the FD stents in the 4 experimental pigs were 16 weeks, 20 weeks, 20 weeks, and 24 weeks postoperatively. All occluded stents were successfully recanalized under DSA, with a technical success rate of 4/4. Among the 19 non-occluded FD stents, OCT and IVUS revealed uniform (16 stents) or non-uniform (3 stents) neointimal coverage of the stent struts, presenting as homogeneous high/slightly high signal intensity or medium echogenicity. Histopathological examination indicated that the neointima was primarily composed of smooth muscle cells and a small amount of fibrous connective tissues. In contrast, the 4 occluded FD stents demonstrated excessive neointimal proliferation and plaque formation, leading to luminal loss, as shown by OCT and IVUS. The occlusion tissues predominantly presented as homogeneous high signal intensity with weak attenuation (fibrous plaques) on OCT, with some regions showing blurred low signal intensity and strong attenuation (lipid plaques). IVUS presented homogeneous echogenicity (fibrous plaques) and hypoechogenic zones (lipid plaques). Histopathological examination showed that the occlusion tissues mainly consisted of smooth muscle cells, fibrous connective tissues, and lipids, accompanied by numerous foam cells and a minor presence of inflammatory cells.Conclusions:Histopathological examinations confirm that non-acute occlusion of FD is mainly caused by excessive hyperplasia of intima along with the formation of fibrous plaques and lipid plaques. OCT and IVUS have typical finding in imaging that can assist in determining the cause of stent occlusion as well as the lesion's nature, thereby providing crucial guidance for subsequent clinical treatment and drug selection.
