Stent Deployment Pressure Defines the Stent/Vessel Wall Relationship and has Important Implications for Early and Late Outcome.

: OBJECTIVE: This study evaluates the effect of stent deployment pressure on stent deployment, coronary vessel injury, subacute reclosure and foreign body reaction in a porcine coronary model. METHODS: Stainless steel coil stents were deployed in the right coronary artery of 30 pigs either using a deployment pressure of 4 atm (group I), 8 atm (group II), or 14 atm (group III). Serial quantitative angiographic studies together with morphometric analysis of the stented vessels were performed. RESULTS: Three pigs died within 48 hours due to subacute thrombosis (group I: n = 1, group II: n = 0, group III: n = 2). Another 4 stents were found occluded at day 7 (group I: n = 3, group II: n = 0, group III: n = 1). Imperfect stent alignment was found in 8 coronary arteries (group I: n = 7, group II: n = 1, group III: n = 0). Deep protrusion of stent filaments was found in 7 coronary arteries (group I: n = 0, group II: n = 1, group III: n = 6). Area stenosis at 6 weeks of the patent vessels was as follows: 75.7 +/- 15.2% in group I, 31.8 +/- 12.3% in group II, and 66.9 +/- 21.4% in group III, p < 0.001). CONCLUSION: In a porcine coronary model, stent deployment pressure resulting in an optimal alignment and a minimal coronary vessel injury leads to minimal neointimal hyperplasia.