Table 4:

Primary histopathologic findings after coil embolization of experimental aneurysms

Species, Aneurysm	Neck	Dome	Reaction Around and Inside Coils	Inflammation Reaction
Canine, lateral wall^7,41,52,57	Neointima in the obliterated and recanalized aneurysms (170.00 ± 42.43 μm)	Variably organized connective tissue	Neointima and connective tissue tightly adhering to the coils	Minimal inflammatory reaction
Canine, bifurcation^28,29,43,52	Very thin neointima (29.80 ± 24.35 μm); frequent endothelialized clefts	Little-to-no residual thrombus; organized vascularized fibrocellular tissue	Coils apparently bare or covered by a neointimal membrane of variable thickness	Minimal degree of inflammation
Swine, lateral wall^35,41,55,56	Thick fibrous neointimal membrane >1000 μm	Dense fibrotic tissue	Neointima and connective tissue tightly adhering to the coils	Attenuated inflammatory reaction
Rabbit, bifurcation^{8,15,18,30,31}	No endothelialization	No evidence of organized thrombus	Uncovered coils in the lumen and no fibrosis between the loops of coils	Severe chronic or no major inflammatory reaction
Rabbit, elastase^{10,44–46,72}	Partial or complete thin neointimal coverage	Loose hypocellular vascularized connective tissue; no contractile cells and no collagen deposition	No endothelial layer covering the coils close to the aneurysm neck	Marked-to-mild localized chronic inflammatory infiltration