By Ed Susman
NICE, France -- May 23, 2008 -- Surgery to remove blockages in the carotid arteries not only benefits symptomatic patients by removing the embolic source of strokes, but also appears to improve haemodynamics in brain blood flow, according to research presented here at the 17th European Stroke Conference (EuroStroke).
Reseachers using functional magnetic resonance imaging (MRI) found significant improvement in the ipsilateral blood flow compared with blood-flow measurements taken prior to endarterectomy procedures.
"Removal of the embolic source is accepted as the major benefit from carotid endarterectomy," said Stephen Goode, PhD, Research Fellow, Department of Vascular and Endovascular Surgery, Queen's Medical Center, Nottingham, England, United Kingdom. Most of the studies of other effects, however, have been performed using transcranial Doppler ultrasound. Dr. Goode said data regarding the impact of surgery on the middle cerebral artery (MCA) may be insufficient.
"The aim of our study was to assess the haemodynamic effects of carotid endarterectomy on cerebrovascular reperfusion using functional MRI," Dr. Goode explained in his poster presentation on May 17.
The research team enrolled 15 patients into the study, all of whom were diagnosed with symptomatic internal carotid-artery stenosis. The patients underwent MRI before surgery and then 4 to 8 weeks following surgery. The researchers assessed differences in perfusion, comparing side-to-side asymmetry in the brain. Those differences were calculated using the Hemispheric Asymmetry Index (HAI).
The imaging studies indicated a significant (P = .02) improvement in ipsilateral MCA-territory cerebrovascular reperfusion following carotid endarterectomy. "There was, however, no improvement in cerebrovascular reperfusion in the contralateral [MCA] territory," Dr. Goode reported.
The team also reported that there was a significant change in the HAI following surgery. Before surgery, the HAI was 2.42; after surgery the HAI was -1.72 (P = .025).
"These findings show that carotid endarterectomy benefits patients not only by removing the embolic source, but also by improving patients' cerebral haemodynamics," Dr. Goode concluded.
[Presentation title: Improvement of Patients Cerebrovascular Reserve Following Carotid Endarterectomy.]
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