COMPARATIVE EFFECTIVENESS OF INTRAVASCULAR STENTS IN RESISTING ARTERIAL VASOCONSTRICTION - EVALUATION WITH USE OF INTACT ELASTIC (RABBIT AORTA) AND MUSCULAR (DOG CAROTID) ARTERIES IN AN EX-VIVO MODEL

PURPOSE: The ability of three different intravascular stents (Gianturc o-Roubin, Palmaz-Schatz, and CV Rad), and two different metals (stainl ess steel and tantalum) to resist vasoconstriction was evaluated in an intact artery ex vivo model. MATERIALS AND METHODS: Stents were deplo yed in 21 rabbit thoracic aortae and five dog carotid arteries, which were constricted with phenylephrine and serotonin, respectively, Vasoc onstriction was measured with the use of high-frequency ultrasonic ima ging. RESULTS: The maximal vasoconstriction of the control segment was 37.7% +/- 2.6 with rabbit aortae and 36.3% +/- 4.1 with dog carotid a rteries, while the average maximal constriction for all segments in wh ich stents were placed was 5.7% +/- 1.1 (P < .01). The maximal constri ction of the Gianturco-Roubin stainless steel stent was 9.4% +/- 2.7 v ersus 7.9% +/- 1.6 with the tantalum version (P = .65). Both designs s howed somewhat greater constriction compared with either the Palmaz-Sc hatz (3.3% +/- 0.9) or the CV Rad (1.4% +/- 1.1) stents. CONCLUSIONS: Although all of the stents tested substantially resist arterial vasoco nstrictive forces, the Palmaz-Schatz and CV Rad stents resist vasocons triction to a greater degree than the Gianturco-Roubin stents. Tantalu m and stainless steel stents of the same design (Gianturco-Roubin) app ear similar in their ability to resist vasoconstrictive forces.