Carotid perivascular adipose tissue in CT before and after treatment for severe internal carotid artery stenosis

Purpose: The study aim is to assess how surgical or endovascular treatments can impact carotid perivascular inflammation in patients affected by severe carotid artery stenosis. Methods: Seventy consecutive patients with unilateral carotid stenosis from the BAROX trial were included in this study. CT angiography (CTA) exams were conducted on a dual-source CT system before and after the carotid endarterectomy (CEA) or stenting. Perivascular adipose tissue (PVAT) CT attenuation measurement in a 40 mm proximal segment of the internal carotid artery was measured as carotid PVAT (CPVAT). CT attenuation was calculated as the mean attenuation of all voxels in the range of -30 to -190 HU, thresholds used for identifying adipose tissue. Results: The median CPVAT measurements before and after both surgical and percutaneous procedures in the stenotic side was -60 (-66, -57) before and -61 (-66, -56) after procedure (p = 0.046). The median CPVAT measurements before and after the surgical procedures was -59 (-66, -57) before and -59 (-62, -54) after procedure (p = 0.006). As well as before- and after stent placement was -60 (-65, -55) before and -65 (-70, -60) after procedure (p = 0.103). A correlation analysis showed a positive correlation between post-procedure CPVAT and the occurrence of the procedure (ρ = 0.403, p = 0.003), as well as a positive correlation between pre- and post-procedure CPVAT on the untreated side and the degree of stenosis (pre-procedure: ρ = 0.328, p = 0.007; post-procedure: ρ = 0.271, p = 0.027). Conclusion: We found an increase in CPVAT following CEA, indicating that an inflammatory process occurs during treatment.