Bifurcation lesion stenting remains an area for translational research focus, since provisional stenting, while commonly used, may be inadequate in many cases and currently available ‘bifurcation’ stents are limited.Methods
We have developed a novel side branch stent with a modifiable end through controlled longitudinal shortening, allowing adaptation to any bifurcation angle.Results
Design optimisation and computational finite element analysis resulted in good virtual bifurcation apposition. Safety testing data informed laser-cutting of cobalt chromium prototypes with appropriate tensile stress characteristics, and deployed in silicone bifurcation model -λ and Y shapes at 60o, 45o angles, MicroCT showed only 2.8% mal-apposed struts; mean wall distance 0.03±0.02 mm. Mechanical testing showed low recoil (4.01%±1.31%) and foreshortening (2.15%±0.68%) and good radial strength (malleable end 0.21±0.01 N/mm, regular part=0.24±0.01 N/mm). The optimally performing prototype (Iteration7) was deployed in 20 porcine coronary bifurcations, with initial MicroCT indicating minimal stent protrusion into main/side branch lumen and complete bifurcation angle coverage (figure 1).Conclusion
4 years of bench, in-vitro and in-vivo studies show proof-of-concept that an in-vivo modifiable stent can be used to stent coronary bifurcation side-branches. Work towards first-in-man studies is on-going.