Abstract 346: Mri Guided Experimental Study To Determine The Mechanistic Performance Of Vessel Prep V. Poba In Infrapopliteal Lesions

Abstract

Objective: To present initial results of an ongoing ex-vivo experimental study to compare vessel preparation with intravascular lithotripsy (IVL) or orbital atherectomy (OA) versus plain old balloon angioplasty (POBA) in tibial arteries. Method: We will study amputated limbs that have concentric calcification, in three arms, 1. POBA, 2. IVL, and 3. OA. Amputated limbs are first scanned on 7T MRI using UTE (Ultra-short echo time) and T2 weighted sequences to characterize target lesions with concentric calcium at high resolution. The diameter of balloon is sized based on diameter of the vessel proximal and distal to target lesion and confirmed with intravascular ultrasound (IVUS). A through-and-through wire is placed and angiography and IVUS are performed. POBA, IVL or OA is performed. In lesions with vessel prep, angioplasty is performed. All angioplasties are performed at minimum pressure required for the balloon to reach profile diameter. Finally, the ex-vivo harvested specimens are imaged in 9.4T MRI for 3-D plaque analysis prior to histologic sectioning and staining. Results: We have 7 experiments, 3 BKA and 4 AKA. Balloon angioplasty without vessel prep was performed in 3/7, OA in 2/7 and IVL in 2/7. Lesions angioplastied without vessel prep required higher than burst pressure to reach profile. Lesions treated with OA and IVL required pressures between nominal and burst to reach profile. POBA samples demonstrated plaque disruption and dissections with more luminal gain compared with lesions that underwent vessel prep prior to angioplasty. Conclusion: This study elucidates the mechanism of vessel prep and how it assists POBA in protecting the vessel wall. Vessel prep did not “debulk” or improve luminal gain substantially but required lower inflation pressures and had less uncontrolled dissections and disruptions of the vessel wall. Initial results demonstrate a compelling indication for vessel preparation in select tibial lesions with 360-degree concentric calcium.