Abstract No. 39 Association Between Quantitative Perfusion Using Catheter-Directed Computed Tomography and Clinical Success in Patients with Critical Limb-Threatening Ischemia

This study aims to analyze the correlation between quantitative improvement in blood flow to the foot, calculated using catheter-directed foot computed tomography (CT) perfusion studies before and after angioplasty, and clinical success in 6 months for patients with critical limb-threatening ischemia (CLTI). The institutional review board approved this study. 18 patients with CLTI who received a catheter-directed foot perfusion CT before and after peripheral artery intervention using an Angio-CT scanner. Blood flow (BFD mL/100g/min), blood volume (BVD mL/100g), and mean transit time (MMTD seconds) were calculated in regions of interest (ROIs). Four ROIs were placed on the skin using the angiosome concept (medial plantar, lateral plantar, dorsal pedis, and heel areas) to assess skin perfusion. These four perfusion areas were classified into direct or indirect perfusion areas based on wound location in the angiosome. Additionally, the average value of all four areas was calculated as the value of whole foot perfusion. The percent change in these values between pre- and post-angioplasty was calculated as pre-post ratios, and it was compared with clinical success using the Mann–Whitney U test. Clinical success was defined as wound healing or improvement of ischemic pain without above-ankle amputation or major surgical intervention within 6 months. Clinical success was seen in 12 of 18. Significant differences were observed in the pre-post ratios of BFD and BVD in the indirect and whole foot areas between patients with and without clinical success. Comparison of pre-post ratios for patients with clinical success versus those without: BFD 84.62 vs. 2.82 (p = 0.007) and BVD 131.00 vs. 3.23 (p = 0.007) in the indirect areas; BFD 95.85 vs. 20.20 (p = 0.031) and BVD 98.41 vs. 15.34 (p = 0.015) in the whole foot area. Although an increase in BFD and BVD following angioplasty was observed in the direct areas, no significant association of increase in these ratios with clinical success was demonstrated. Significant differences were found in the increase ratio of BFD and BVD in the indirect and whole foot areas between patients with and without clinical success. There appears to be less immediate change in perfusion in the areas of wounds.