If a vessel is 100% blocked (not 90 or 95%), it is very hard to do anything with a stent to it, and due to risk of
sending some of
the blockage further into the brain, the risk of stroke
is very high and likely not of benefit. Surgery (Carotid Endarterectomy, or CEA) can be done to open the artery and scrape the plaque out and restore flow through the vessel, but bleeding is a risk.