Incidence and mechanism of post-carotid endarterectomy hypertension
J. L. Skydell, H. I. Machleder, J. D. Baker, R. W. Busuttil and W. S. Moore
Department of Surgery, UCLA Medical Center 90024.
Hypertension following carotid endarterectomy occurs frequently but is
poorly understood. Its occurrence has been correlated with an increased
incidence of neurologic complication. We identified those factors that
correlate with an increased incidence of post-carotid endarterectomy
hypertension. The records of 100 patients who underwent carotid
endarterectomy at UCLA Medical Center from November 1981 to September 1983
were examined. One hundred fifty variables were surveyed to determine those
factors associated with this problem. Fifty-eight percent of the study
patients developed post-carotid endarterectomy hypertension (an increase in
systolic blood pressure greater than 35 mm Hg over baseline, and/or blood
pressure requiring treatment with sodium nitroprusside). Of patients who
developed this problem, 93% had diabetes mellitus, 75% received isoflurane
anesthesia, 71% had peripheral vascular occlusive disease, 71% underwent
ipsilateral transient ischemic attacks, and 65% had high-grade ipsilateral
carotid stenosis. These variables have in common the loss of or
interference with cerebral autoregulation. Central dysautoregulation may
set the stage for a positive feedback mechanism that results in increased
blood pressure. Anesthetic agents that do not interfere with cerebral
autoregulation may reduce the incidence of this complication, and an
aggressive treatment program may prevent neurologic complications.
