Demonstrating patency of STA-MCA anastomosis with Tc-99m albumin microspheres

A patient with occlusion of the left internal carotid artery underwent an anastomosis between branches of the left superficial temporal and middle cerebral arteries (STA-MCA). A left carotid angiogram 9 days later showed extreme, tapered narrowing of the involved STA branch, with no filling of the MCA from the bypass. A year later, symptoms had improved slightly, and a minimally invasive study was made with Tc-99m human albumin microspheres. This showed patency of the bypass, with intracranial perfusion in the MCA field, findings later confirmed by a repeat left carotid angiogram. It appears that Tc-99m HAM scintigraphy will be useful in assessing the effectiveness of this and other bypass operations.