Author + information
- Duncan C. McNab, MB, BS, MPhil⁎ (, )
- John Ormiston, MB, ChB and
- Mark W.I. Webster, MB, ChB
- ↵⁎Auckland City Hospital, Cardiology, Park Road, Grafton, Auckland, 1005, New Zealand
We read with interest the study by Costa et al. (1) clarifying a number of important aspects of the treatment of bifurcation lesions by the crush technique. The investigators reported that “the majority of SB (side branch) lesions showed stent underexpansion with the smallest MSA (mean sent area) found at the SB ostium,” and that this underexpansion was not reliably detected by angiography. Given the potential implications of these findings on the development of both stent thrombosis and restenosis at the ostium of the SB, it would be interesting to know additional details on how the crush technique was performed in this study. Bench-testing has demonstrated procedural issues that maximize the likelihood of adequate dilation of the SB ostium, including ensuring that the SB postdilation balloon is the same diameter or larger than the deploying balloon (2).
In addition, Colombo (3) has described the importance of performing “before kissing, a high-pressure balloon inflation in the side-branch so as to be sure to expand the stent fully at the ostium.” Costa et al. (1) also found that “incomplete stent apposition in the crush area was common.” Some operators deliberately undersize the main vessel (MV) balloon during kissing inflation to avoid “oversizing” by the double balloons at the proximal end of the MV stent. We have previously shown that this leads to MV stent distortion (2,4) and incomplete crushing (2) and that these outcomes can be prevented or repaired by kissing with appropriately sized balloons in the MV and SB.
Finally, it is not clear whether Costa et al. (1): 1) performed a separate high-pressure inflation in the SB before kissing; 2) whether the MV and SB balloons were smaller, the same size, or larger than the deploying balloons (the reported stent and final balloon diameters are a mean of the study population); and 3) what pressures were achieved in the SB and MV balloons during kissing inflations. This information is particularly pertinent for those cases in which the MSA of the SB ostium was <4 mm2and when incomplete crushing was observed.
- American College of Cardiology Foundation