Back to 2025 Abstracts
Utilizing MRI-histology To Identify Plaque Composition Features That Predict Percutaneous Vascular Interventional Crossing Failures In An Ex Vivo Model
Alexander Crichton, MBChB, MS, Judit Csore, MD, PhD, Bright Benfor, MD, Peter Osztrogonacz, MD, Christof Karmonik, PhD, Trisha Roy, MD, PhD.
Houston Methodist Research Institute, Houston, TX, USA.
OBJECTIVES:Not all peripheral artery disease (PAD) lesions are suitable for endovascular intervention, due to inability to cross the lesion. Conventional imaging often provides limited insight into plaque characteristics. However, state-of-the-art ultrashort echo time (UTE) MRI sequences have demonstrated the ability to detect impenetrable PAD lesions ex vivo by distinguishing between soft (loose fibrous tissue, thrombus, fat, microchannels) and hard (calcification, dense collagen) plaque structures. This study aimed to determine if MRI combined with histology can identify impenetrable plaques in ex vivo amputated leg models.
METHODS: 17 amputated legs from chronic limb-threatening ischemia (CLTI) patients were scanned ex vivo on a 3T MRI scanner. Lesions with >75% stenosis identified were targeted. Lesions were classified as ‘hard’ if > 50% of the lumen was occluded by calcium or dense collagen. The distribution of the hard component (eccentric, concentric central), lumen stenosis caused by hard and soft components, and collagen density component were recorded. Percutaneous interventions were then performed in a hybrid operating room. Vessel patency and lesion characteristics were evaluated using MRI, preoperative ultrasound, and digital subtraction angiography.
RESULTS:17 patients yielded 29 target lesions (2 TPT, 14 AT, 10 PT, 3 peroneal), with 76% (22/29) classified as ‘hard’ (figure 1) of which 45% of these lesions had a composition that was mainly collagen rather than calcific. 'Hard' lesions had a significantly higher rate of crossing failure compared to 'soft' lesions (95% vs. 14%, p<.001). MRI scoring of 'hard' lesions was significantly associated with immediate PVI crossing success (p < .001) outperforming TASC and GLASS scoring (p=.062 and p=.112, respectively), whereas the presence of total vessel occlusion was not predictive of failure (p=0.64). Most crossing failures (64%) occurred in ‘hard lesions with a ‘central’ distribution, but the association was not significant.
CONCLUSIONS:This novel MRI-histology based scoring system has identified that plaque composition is one of the most important factors in predicting PVI failure. A significant proportion of ‘hard’ lesions in this cohort are collagenous rather than calcific. This highlights the importance of MRI in the pre-operative assessment of patients with CLTI, further guiding pre-operative device selection and the development of new endovascular technologies.
Back to 2025 Abstracts
