The double-kissing nano-crush for bifurcation lesions : development, bioengineering, fluid dynamics and initial clinical testing

Background

When possible, a single stent technique to treat coronary bifurcation disease is preferable. However, when two stents are required, there is scope to improve upon existing techniques. The crush technique has already been improved with the introduction of double kissing (DK) and mini-crush. We sought to refine and simplify the mini-crush technique, retaining its advantages whilst avoiding its disadvantages, by developing a DK nano-crush technique.

Methods

The DK nano-crush method allows complete lesion coverage of a bifurcation lesion without excessive metal layers. This is achieved by positioning the SB stent with minimal protrusion into the main branch (MB), implantation of the SB stent with an undeployed balloon in the MB, immediate kissing balloon inflation with formation of a minimal neocarina, stenting the MB, re-crossing the proximal part of the SB without crossing double metal layer, and final kissing. We demonstrate this technique with benchtop implantation, micro computed tomography reconstruction, computational fluid dynamics (CFD) modelling and clinically with angiographic and intravascular imaging.

Results

The DK nano-crush was practically feasible and resulted in full ostial coverage. CFD analysis demonstrated minimally disturbed blood flow. The technique was successfully utilised in nine patients with bifurcation lesions with excellent angiographic outcomes and no adverse events over twelve months.

Conclusions

The DK nano-crush technique may represent the ultimate refinement of the original ‘crush’ with a number of practical and theoretical advantages. It remains to be tested against other bifurcation techniques in prospective trials.