A Simple Step Towards Better Stent Deployment
- Volume 14 - Issue 5 - May, 2002
- Posted on: 8/1/08
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See Johansson et al. in this issue on pages 221–226
One of the major limitations to obtain appropriate stent expansion is the presence of plaque behind the stent and occasionally the presence of calcium or fibrosis which impair distensibility of the vessel wall.12 Balloon catheters, traditionally used as a first choice, inflate and expand in an asymmetric and inequitable fashion, particularly in the presence of calcified plaques.13 The frequent impossibility to obtain the expected result has limited the usage of IVUS as a tool to optimize stent expansion. For practical reasons, the most frequently used approach is to perform final stent dilatation with the increase in the balloon size.
In this issue of the Journal, the article by Johansson et al.14 deals with this idea of a systematic alternative approach. Stents could be deployed using angiography only — as it is the case at the present time, but using a standardized stent “over-dilatation” this goal could be achieved by an increment of 0.25 mm in balloon size, and high balloon pressure (16.1 ± 1.7 atm) for final stent deployment. An IVUS evaluation in all 37 studied lesions was done as well to document the optimize results with this technique. Compared to a historical group of patients, the standardized over-dilation achieved a larger MLD (3.0 ± 0.4 mm versus 2.7 ± 0.4 mm; p = 0.03), more stents achieved a minimal lumen area (MLA) of > 9 mm2 (46% versus 11%; p = 0.02) and more patients fulfilled AVID (Angiography-directed Versus Ivus-Directed coronary stent placement) study criteria for stent expansion (70% versus 32%; p = 0.048). Although there were no acute complications, no stents achieved a nominal size in spite of over-dilatation, and no differences in clinical variables were seen at 1-year follow-up. Thus, what is the value of this study?