Related Experiment Video
Updated: Aug 11, 2026
Integrated Compensatory Responses in a Human Model of Hemorrhage
Published on: November 20, 2016
The collateral hemispheric systolic pressure
Insights
This study found that collateral hemispheric systolic pressure during carotid endarterectomy depends on the opposite carotid artery's condition and central blood pressure. Formulas were derived to ensure adequate pressure for brain integrity.
Area of Science:
- Neurosurgery
- Vascular Surgery
- Neurology
Background:
- Carotid endarterectomy is a common procedure to prevent stroke.
- Maintaining adequate cerebral blood flow during surgery is crucial for preventing neurological deficits.
- Assessing collateral circulation is vital for patient safety during carotid interventions.
Purpose of the Study:
- To develop predictive formulas for collateral hemispheric systolic pressure.
- To determine the relationship between central blood pressure, contralateral carotid artery status, and collateral pressure.
- To establish criteria for adequate collateral pressure to ensure hemispheric integrity during and after carotid occlusion.
Main Methods:
- Obtained calibrated blood pressure tracings during 385 carotid endarterectomies.
- Measured pressures from the distal common carotid artery with external carotid artery occlusion.
- Recorded continuous pressures with and without proximal common carotid clamp occlusion.
Main Results:
- Developed distinct formulas for patients with severe contralateral carotid stenosis/occlusion (n=101) and those without (n=284).
- Demonstrated that collateral hemispheric systolic pressure is influenced by the contralateral carotid artery's condition and central blood pressure.
- Established a method to demarcate the lowest adequate collateral hemispheric systolic pressure.
Conclusions:
- Collateral hemispheric pressure is significantly influenced by the contralateral carotid artery's status.
- Derived formulas provide a basis for assessing the adequacy of collateral circulation during carotid surgery.
- These findings aid in optimizing patient management to prevent perioperative stroke.
Abstract:
Satisfactory calibrated BP tracings were obtained during 385 (85%) of 455 carotid endarterectomies. The pressures were measured from the distal common carotid arteries while the external carotid arteries were clamp occluded. Continuous recordings were made with and without proximal common carotid clamp occlusion. The two systolic pressures resulting in each patient were plotted as a single point on a graph, with the direct carotid systolic pressure on the abscissa and the back carotid systolic pressure on the ordinate. Formulae of the mean values in 101 of the 385 procedures, in which the opposite carotid systems contained severe stenoses or total occlusions, and the other 284 procedures, in which the opposite carotid systems had no notable lesions, demonstrate that the collateral hemispheric systolic pressure depends on the status of the opposite carotid artery and on the central BP. We derived formulae for these two groups of patients to demarcate the lowest collateral hemispheric systolic pressure adequate for hemispheric integrity during and following prolonged operative carotid occlusion or following permanent interruption of carotid blood flow as a result of thrombosis, ligation, or resection without graft replacement.
Related Concept Videos
01:21Sites for measuring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
01:28Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
01:24Blood Pressure
01:17Measurement of Blood Pressure
01:14Increased Intracranial Pressure l: Introduction
01:29Increased Intracranial Pressure ll: Pathophysiology