Intracranial stenting for intracranial atherosclerotic disease: still much to learn
- Correspondence to Dr Michael J Alexander, Cedars-Sinai Medical Center, Department of Neurosurgery, 8631 West Third Street, Suite 800E, Los Angeles, CA 90048, USA;
- Accepted 10 January 2012
The recently published Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) study1 has provided seminal information on the treatment of symptomatic intracranial atherosclerotic disease (ICAD). However, with some perceived study design flaws and patient group exclusions, this study is only one of the first steps in understanding how best to manage patients with symptomatic ICAD medically and with endovascular therapy. To believe the editorial and media commentary that this is the definitive word on management of this complex problem would be naïve. As with nearly every new vascular device, the first-generation device involves a learning curve. Early coronary and carotid stents demonstrated poor clinical results,2 3 but now these are staples in our management of vascular disease. Doubtless, stenting for ICAD will be similar once the correct adjunctive medical regimen and patient selection criteria are established.
Heterogeneity of ICAD
ICAD is complex and may cause symptomatic stroke or transient ischemic attacks (TIA) in various ways. First, severe atherosclerotic disease may exhibit irregular or ruptured plaque which may lead to emboli distal to the stenosis. Second, severe ICAD in a relatively isolated vascular territory may lead to ischemic hypoperfusion in that territory. Finally, a feature that is distinct from coronary atherosclerotic disease, ICAD may lead to perforator strokes due to plaque occlusion of side perforator arteries. Based on these presentations, it would be reasonable to speculate that medical therapy may be best in some presentations and stenting better in others (in fact, stenting may be relatively contraindicated in the third group due to the possibility of the ‘snow plow’ effect worsening perforator occlusion). Unfortunately, all three of these patient groups were combined in the SAMMPRIS study, making analysis difficult.
Patients with the second type of presentation are often hemodynamically unstable with regard to cerebral blood flow, sometimes …