Carotid Stump Pressure and Contralateral Internal Carotid Stenosis Ratio During Carotid Endarterectomies: 1D-0D Hemodynamic Simulation of Cerebral Perfusion

Sohei Matsuura; Toshio Takayama; Changyoung Yuhn; Marie Oshima; Takuro Shirasu; Takafumi Akai; Toshihiko Isaji; Katsuyuki Hoshina

doi:10.3400/avd.oa.20-00166

Carotid Stump Pressure and Contralateral Internal Carotid Stenosis Ratio During Carotid Endarterectomies: 1D-0D Hemodynamic Simulation of Cerebral Perfusion

Ann Vasc Dis. 2021 Mar 25;14(1):39-45. doi: 10.3400/avd.oa.20-00166.

Authors

Sohei Matsuura¹, Toshio Takayama¹, Changyoung Yuhn², Marie Oshima³, Takuro Shirasu¹, Takafumi Akai¹, Toshihiko Isaji¹, Katsuyuki Hoshina¹

Affiliations

¹ Division of Vascular Surgery, Department of Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
² Department of Mechanical Engineering, The University of Tokyo, Tokyo, Japan.
³ Interfaculty Initiative in Information Studies, The University of Tokyo, Tokyo, Japan.

Abstract

Objective: We selectively place carotid shunting when ipsilateral mean stump pressure is less than 40 mmHg during carotid endarterectomy (CEA). This study aimed to assess the validity of our selective shunting criterion by 1D-0D hemodynamic simulation technology. Materials and Methods: We retrospectively reviewed 88 patients (95 cases) of CEA and divided them into two groups based on the degree of contralateral internal carotid artery (ICA) stenosis ratio, which was determined as severe when the peak systolic velocity ratio of the ICA to the common carotid artery was ≥4 by carotid duplex ultrasonography. Patients with severe stenosis or occlusion in contralateral ICA were classified as hypoperfusion group, and those without such contralateral ICA obstruction were classified as control group. Results: Perioperatively, the mean carotid stump pressures were 33 mmHg in hypoperfusion group and 46 mmHg in the control group (P=0.006). We simulated changes in carotid stump pressure according to the changes in the contralateral ICA stenosis ratio. 1D-0D simulation indicated a sharp decline in carotid stump pressure when the contralateral stenosis ratio was >50%, while peripheral pressure of the middle cerebral arteries declined sharply at a ≥70% contralateral stenosis ratio. At this ratio, the direction of the ipsilateral cerebral arterial flow became inverted, the carotid stump pressure became dependent on the basilar artery circulation, and the ipsilateral middle cerebral artery became hypoperfused. Conclusion: Our clinical and computer-simulated results confirmed the validation of our carotid shunting criterion and suggested that contralateral ICA stenosis ratio over 70% is a safe indication of selective shunting during CEA.

Keywords: carotid endarterectomy; carotid stenosis; cerebral collateral circulation; circle of Willis.