Expansion of Wiktor stents by oversizing versus high-pressure dilatation: A randomized, intracoronary ultrasound-controlled study

Two strategies to achieve optimal expansion of Wiktor stents in coronary arteries, oversizing at normal balloon pressures (group 1) and high-pressure dilatation (group 2), were compared. We randomly assigned 20 symptomatic patients with de novo coronary artery stenoses of <15 mm length to one of the two treatment groups. Intracoronary ultrasound catheter pull-backs after stent im plantation showed incomplete stent attachment with one or two struts protruding into the vessel lumen in 3 of 10 patients in group 1 but in no patient after high-pressure dilatation in group 2 (p < 0.01). Recross and high-pressure dilatation of the 3 stents in group 1 achieved complete attachment of all stents. Minimal luminal diameter was comparable between the groups (2.61 +/- 0.34 mm in group 1 after stent delivery, and 2.68 +/- 0.45 mm in group 2 after high-pressure dilatation). Minimal luminal area (expressed as a percentage of the reference cross-sectional area) was slightly but insignificantly greater in the high-pressure group (91.1% +/- 25.6% vs 85.5% +/- 15.1%). We conclude that implantation of Wiktor stents at normal inflation pressures does not reliably result in complete attachment of all struts to the vessel wall.