Fibrinogen and Vascular Smooth Muscle Cell Grafts Promote Healing of Experimental Aneurysms Treated by Embolization

Abstract
Background and Purpose—Residual necks and recurrences frequently occur after endovascular treatment of cerebral aneurysms. Addition of fibrinogen and vascular smooth muscle cells (VSMCs) to the embolic material may promote healing of embolized aneurysms by increasing neointima formation at the neck. Methods—Bilateral carotid aneurysms were constructed with venous pouches in 31 dogs. Aneurysms were packed intraoperatively with bare Gelfoam sponges, sponges treated with fibrinogen, or fibrinogen sponges seeded with the animal’s own VSMCs or peripheral blood mononuclear cells. Animals were killed after angiography at 3 weeks, and morphometric studies were performed to measure the thickness of the neointima at the neck of treated lesions. Angiographic results and mean thickness of neointimas were compared using ANOVA. In 8 animals, 1 aneurysm was embolized with sponge seeded with VSMCs transduced by adenoviral infection to express a fluorescent protein (green fluorescent protein), and gene expression was moni...