Proximal balloon occlusion protects brain during CAS
MedWire News: Proximal balloon occlusion provides greater cerebral protection than use of a distal filter during carotid artery stenting (CAS), in what the researchers say is the first randomized comparison of the two techniques.
The study, which appears in the Journal of the American College of Cardiology, included 62 patients (76.4% men) aged an average of 71.7 years. The same experienced operator performed all CAS procedures, using the same type of stent and balloon or filter for all patients.
The patients underwent diffusion-weighted magnetic resonance imaging (DW-MRI) after stenting. This revealed new cerebral ischemic lesions in 45.2% of patients randomly assigned to use of distal filters versus 87.1% in those assigned to proximal balloon occlusion, which was a statistically significant between-group difference.
There were an average of 3.6 versus 1.0 new cerebral ischemic lesions in the distal filter versus the balloon occlusion group, and the average volume was also reduced, at 0.59 versus 0.16 cm3.
The reduction in new cerebral lesions was apparent for symptomatic and asymptomatic patients and for those older than 80 years, although the reduction for octogenarians was not statistically significant.
Balloon intolerance has been raised as a potential drawback to the procedure, note Joachim Schofer (Hamburg University Cardiovascular Center, Germany) and colleagues. The team screened all patients with magnetic resonance angiography and excluded those with probable contraindications, such as contralateral occlusion and an incomplete circle of Willis. Yet three of the 31 patients in the balloon occlusion group displayed neurologic symptoms on balloon inflation that disappeared on deflation.
However, the researchers note that all procedures were completed under cerebral protection, despite intolerance.
"Although the DW-MRI findings were mostly clinically unapparent, they are the tip of the iceberg of what is happening to the brain during CAS," say Schofer et al.
"In the present study, proximal balloon protection reduced the incidence of new ischemic lesions by a factor of 1.9. Whether the findings of the present study translate to a lower stroke rate remains to be shown in a randomized trial with clinical endpoints."
MedWire (http://www.medwire-news.md/) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Eleanor McDermid