Components of carotid atherosclerotic plaque in spectral photon-counting CT with histopathologic comparison.

OBJECTIVES: This study aimed to demonstrate the effectiveness of spectral photon-counting CT (SPCCT) in quantifying fibrous cap (FC) thickness, FC area, and lipid-rich necrotic core (LRNC) area, in excised carotid atherosclerotic plaques by comparing it with histopathological measurements. METHODS: This is a single-center ex vivo cross-sectional observational study. Excised plaques of 20 patients (71 +/- 6 years; 13 men), obtained from carotid endarterectomy were scanned with SPCCT using standardized acquisition settings (120k Vp/19 µA; 7-18 keV, 18-30 keV, 30-45 keV, 45-75 keV, and 75-118 keV). FC thickness, FC area, and LRNC area were quantified and compared between high-resolution 3D multi-energy CT images and histopathology using the Wilcoxon signed-ranks test and Bland-Altman analysis. Images were interpreted twice by two radiologists separately, blinded to the histopathology; inter- and intra-rater reliability were assessed with the intra-class correlation coefficients (ICC). RESULTS: FC thickness and FC area did not show significant differences between the SPCCT-derived radiological measurements versus the histopathological measurements (p value range 0.15-0.51 for FC thickness and 0.053-0.30 for FC area). For the LRNC area, the p value was statistically non-significant for reader 1 (range 0.36-0.81). The Bland-Altman analysis showed mean difference and 95% confidence interval for FC thickness, FC area, and LRNC area, 0.04 (-0.36 to 0.12) square root mm, -0.18 (-0.34 to -0.02) log10 mm2 and 0.10 (-0.088. to 0.009) log10 mm2 respectively. CONCLUSION: The result demonstrated a viable technique for quantifying FC thickness, FC area, and LRNC area due to the combined effect of high spatial and energy resolution of SPCCT. KEY POINTS: • SPCCT can identify and quantify different components of carotid atherosclerotic plaque in ex vivo study. • Components of atherosclerotic plaque did not show significant differences between the SPCCT-derived radiological measurements versus the histopathological measurements.

Operative and 1-Year Outcomes of the Custom-Made Fenestrated Anaconda Aortic Stent Graft-A UK Multicenter Study.

BACKGROUND: Early and 1-year outcomes are presented for fenestrated endovascular aneurysm repair (FEVAR) of complex aortic aneurysmal disease with the custom-made Anaconda fenestrated stent graft in 101 patients. METHODS: Retrospective site-reported data from the first 101 elective cases (2010-2014) from 4 UK centers were studied to evaluate patient demographics, aneurysm morphology, clinical success, and 1-year outcomes in patients undergoing fenestrated aneurysm repair with the custom-made Anaconda device. RESULTS: 101 fenestrated grafts (median age 76, 85% male) were implanted with a total of 255 fenestrations (196 renal arteries, 48 superior mesenteric artery, and 11 celiac arteries) with 3% mortality, 98.4% target vessel patency (TVP) at 30 day follow-up. Although 15 type I or III endoleaks were demonstrated at completion angiography, all 10 type Ia endoleaks resolved spontaneously. Survival by Kaplan-Meier analysis was 97% and 91% at 1 month and 1 year, respectively; with 75.8% showing reduction in abdominal aortic aneurysm diameter and only 1 patient with sac expansion. Freedom from loss of TVP was 97.6%. CONCLUSIONS: Custom-made fenestrated Anaconda devices demonstrate low procedural mortality and a high rate of technical and clinical success at 30 days and 1 year.