Original title: Duration of Balloon Inflation for Optimal Stent Deployment: Five Seconds Is Not Enough. Reference: Thomas Hovasse et al. Catheterization and Cardiovascular Interventions 81:446–453 (2013).

Adequate stent expansion and apposition to the vessel wall is essential to optimize the results of percutaneous transluminal coronary angioplasty (PTCA).

If the above is not adequate, it increases the risk of thrombosis and restenosis for both conventional stents and DES. Currently there are no recommendations on how much time is required for balloon inflation and correct stent implantation. Intravascular ultrasound (IVUS) is the technique of choice to determine the correct stent implantation but nevertheless, is not yet possible to use it in order to determine the effect of inflation on the length of stent expansion. 

The StentBoost, (Philips Medical Systems, Best, the Netherlands), correlates well with IVUS and is superior to conventional angiography. The objective of this study was to assess the relationship between the length of the balloon inflation and stent deployment expansion, using the same StentBoost. We included 104 consecutive patients which underwent PTCA in de novo lesions with stent expansion measured at 5, 15 and 25 seconds using StentBoost. Cypher stents (54%), Xience V (30.6%) and Taxus Liberté (15.3%) were used.

The duration of the insufflation significantly influenced stent expansion. After 5 seconds the minimum diameter was 2.6 ± 0.51 mm, increasing to 2.76 ± 0.51 at 15 sec (p <0.0001) and reaching 2.82 ± 0.52 mm at 25 sec (p <0.0001). Although there is 29.3% still required post dilation. Applying MUSIC, (Multicenter Ultrasound Stenting in Coronaries) criteria, the proportion of under expansion stents gradually decreased from 31.3% at 5 sec distension to 3.3% at 15 seconds and finally 2% at 25 seconds (p <0.0001).

Conclusion: 

Balloon inflation time during stent release had a significant impact on stent expansion. The authors recommend blowing for at least 25 seconds in daily practice.

Editorial Comment: 

Although no IVUS was performed, which is the gold standard for assessing the proper expansion and apposition of a stent, there is evidence that the assessment with StentBoost has an acceptable correlation. These technologies are often available in the catheterization room and yet are underutilized because of the time needed. We must regain a bit of the patience we show at the time of balloon angioplasty for better expansion and apposition of the stent at this time.

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