Wall shear stress and oscillatory shear index after carotid endarterectomy in the postoperative period

Objective. To evaluate changes in the shear stress of the internal carotid artery (ICA) wall after carotid endarterectomy (CEAE) in the remote postoperative period. Material and methods of the study. 26 patients (65±2.9 years old) with ICA pathology were examined before surgery, with an average degree of stenosis of 80.4±3.3% (64–95%). According to echogenicity, the distribution of plaques was as follows: predominantly hypoechoic – 12, hyperechoic – 10, and isoechoic – 4. After carotid endarterectomy (CEAE) in the hospital period, satisfactory echolocation allowed for the examination of 19 patients (61.6±2.7 years). In the long-term period, 12 patients (63.1±2.0 years) were examined 6–14 months later. The study was conducted using a Mindray Resona 7 ultrasound scanner (China) and a linear sensor (2.5–9 MHz) in V-flow mode. Systolic blood f low velocity (Vs), wall shear stress (WSS), and blood flow turbulence were assessed using vector analysis before and after stenosis. The change in the direction of the WSS vector during the cardiac cycle was described using the Oscillatory Shear Index (OSI). The intra-group correlation coefficient was calculated for the measurement of wall stress and shear. Results. Before surgery, ICA stenosis is characterized by changes in WSS in different parts of the artery and increased blood flow turbulence. The adequacy of the CAEA operation was assessed based on the dynamics of changes in blood flow velocity and the ratio of wall shear stress to the proximal and distal vessels. In the long-term postoperative period, the direction and velocity of the flow vectors approach normal values, which serves as one of the hemodynamic indicators of the adequacy of surgical correction of ICA stenosis. Conclusion. The criteria for adequate correction were the normalization of intravascular blood flow, wall shear stress, and oscillation index, as well as the reduction of blood flow turbulence. The registration of wall shear stress using V-flow in patients with cerebrovascular diseases represents a new approach for evaluating the results of surgical treatment.

1. Yiemeng Hoi, Bruce A Wasserman, Yuanyuan J Xie, et al. // Characterization of volumetric flow rate waveforms at the carotid bifurcations of older adults. Physiological Measurement, 31(3):291–302, March 2010. ISSN 0967-3334, 1361-6579. doi: 10.1088/0967-3334/31/3/002.

2. Qiu YJ, Cheng J, Zhang Q, Yang DH, Zuo D, Mao F, Liu LX, Dong Y, Cao SQ, Wang WP.Qiu YJ, et al. // Clinical Application of High-Frame-Rate Vector Flow Imaging in Evaluation of Carotid Atherosclerotic Stenosis. Diagnostics (Basel). 2023. 31 January; 13(3):519. doi: 10.3390/diagnostics13030519.PMID: 36766624.

3. Meiying Gao Haining Zheng Rui Zhao Rui Zhao. Wall shear stress and oscillatory shear index measured using ultrasound vector flow imaging in the femoro popliteal artery of adults without peripheral artery disease / Vascular Surgery Volume 12 – 2025. https://doi.org/10.3389/fsurg.2025.1597407.

4. Veronique Peiffer, Spencer J. Sherwin, and Peter D. Weinberg. // Does low and oscillatory wall shear stress correlate spatially with early atherosclerosis? A systematic review. Cardiovascular Research, 2013.99(2):242–250. ISSN1755-3245,0008-6363. doi:10.1093/cvr/cvt044. URL:https://academic.oup.com/cardiovascres/article-lookup/doi/10.1093/cvr/cvt044.

5. Lenard Z , Fulop D, Visontai Z, Jokkel G, Reneman R, Kollai M. // Static versus dynamic distensibility of the carotid artery in humans. J.Vasc.Res.2000:37(2):103–111.

6. Ayla Hoogendoorn, Annette M. Kok, Eline M. J. Hartman, et al. // Multidirectional wall shear stress promotes advanced coronary plaque development: comparing five shear stress metrics. Cardiovascular Research, 116(6):1136–1146, May 2020. ISSN 1755-3245. doi:10.1093/cvr/cvz212.

7. Reneman, R.S., T. Arts, and A.P.G. Hoeks. Wall shear stress – an important determinant of endothelial cell function and structure – in the arterial system in vivo: discrepancies with theory. J. Vasc. Res. 43(3):251–269, 2006. https://doi.org/10.1159/000091648.

8. Wong, E. Y., H. N. Nikolov, R.N. Rankin, D. W. Holdsworth, and T. L. Poepping. Evaluation of distal turbulence intensity for the detection of both plaque ulceration and stenosis grade in the carotid bifurcation using clinical Doppler ultrasound. https://doi.org/10.1007/s00330-012-2741.

9. Chen J, Zhang L, Gu S, Jia C, Wu R. Quantitative evaluation using carotid ultrasonography-based high-frame-rate vector flow imaging in patients with low carotid stenosis. Br J Radiol. 2024 Aug 1;97(1160):1476–1482. doi: 10.1093/bjr/tqae115.PMID: 38885374.

10. David E, Martinelli O, Pacini P, Di Serafino M, Huang P, Dolcetti V et.al. New Technologies in the Assessment of Carotid Stenosis: Beyond the Color-Doppler Ultrasound-High Frame Rate Vector-Flow and 3D Arterial Analysis Ultrasound.Diagnostics (Basel). 2023 Apr 19;13(8):1478. doi: 10.3390/diagnostics13081478.PMID: 37189578.

11. Zhang X, Ding H, Ji X, Chen L, Huang P, et.al. Predicting vulnerable carotid plaques by detecting wall shear stress based on ultrasonic vector flow imaging. Vasc Surg. 2024 Nov;80(5):1475-1486.e1. doi: 10.1016/j.jvs.2024.06.024. Epub 2024 Jun 24. PMID: 38925348.

12. Zhou M, Yu Y, Chen R, Liu X, Hu Y, Ma Z, et al. Wall shear stress and its role in atherosclerosis. Front Cardiovasc Med. (2023) 10:1083547. doi: 10.3389/fcvm.2023.1083547.