Videographic assessment of the embolic characteristics of three polymeric compounds: Ethylene vinyl alcohol, cellulose acetate, and liquid urethane

BACKGROUND AND PURPOSE: Aneurysms have been clinically and experimentally t reated with various surgical and endovascular methods, including endovascul ar polymer instillation, Additional tools may help to identify advantages a nd disadvantages of polymeric aneurysm treatment, We assessed the value of high-resolution videography to compare in vitro embolization characteristic s of ethylene vinyl alcohol copolymer (VIN), cellulose acetate polymer (ACE ), and urethane copolymer (UCO), METHODS: In a "neck-up" glass aneurysm model, solutions of 8% and 12% VIN, 8% and 12% ACE, and 8% UCO were introduced through a microcatheter into a x anthan gum solution at three flow rates: full physiological (62 cm/s), half physiological, and pow arrest, Each formulation was then introduced into a "neck-down" aneurysm model at flow arrest, for a total of 20 experiments. Results were tabulated for six different categories: outflow tail formation , inflow-zone polymer-mass deformation, inflow-zone migration, detachment t ail formation, adherent mass pullout, and conjectural net effect, RESULTS: Of the 20 experiments, nine had unacceptable results because of po tential clinical complications. The results were unacceptable in four of ei ght VIN experiments, four of eight ACE experiments, and one of four UCO exp eriments. VIN performance was more dependent on how arrest than the more vi scous ACE. The growth of the ACE solutions was most circumferential, with b alloonlike growth characteristics, little inflow-zone effects, and fewer ou tflow tails than seen with VIN, All compounds had the potential for partial catheter adhesion and catheter-adhesing tails. UCO had the highest percent age of favorable results and the lowest percentage of unfavorable results, CONCLUSION: Videographic analysis allows detailed assessment of the dynamic embolization characteristics of polymers, revealing potential advantages o f compounds such as UCO.