In vivo assessment of stent recoil in normal porcine arteries: Evaluation of contemporary stent designs

Acute stent recoil has been observed following balloon deflation in normal and diseased coronary arteries, and the magnitude varies by stent design. W e sought to evaluate acute stent recoil in five new stents, Twenty-five ste nts (four Crown, five Nir Conformer Royale, five Crossflex, five SupraG, an d six GFX) were implanted in six Yorkshire pigs, All stents were expanded u sing a noncompliant balloon (balloon:artery ratio 1.2:1.0), Continuous ultr asound imaging was performed during stepwise balloon inflation and deflatio n using a 0.018 " imaging core, Maximum cross-section areas (CSA) and minim al luminal diameter (MLD) were measured at 12 atm and immediately following balloon deflation. Maximum stent CSA matched expected balloon CSA, Area an d diameter recoil were calculated as 1 - (CSA(deflation)/CSA(max)) and 1 - (MLDdeflation/MLDmax, respectively, Upon deflation, all stents showed recoi l from maximal CSA. Area recoil was significantly lower for slotted-tube st ents than modular stents (12.6% +/- 1.6% vs, 23.2 +/- 3.5%; P < 0.05). In c ompliant, nonatherosclerotic porcine coronary arteries, acute stent recoil for the four slotted-tube designs ranged from 8.4% to 18.0% by area, The mo dular stent tested was associated with significantly greater acute recoil t han the slotted-tube stents. (C) 2001 Wiley-Liss, Inc.