Differences in rotational positioning and subsequent distal main branch rewiring of the Tryton stent: An optical coherence tomography and computational study

OBJECTIVES: To evaluate the occurrence of rewiring through one of the panels of the Tryton stent (instead of the assumed re-wiring in-between the panels) and the influence on stent geometry and mechanics.

BACKGROUND: Tryton is a side branch stent used in combination with a main branch device. It is placed without the need of rotational orientation. However, it is unknown whether main branch re-wiring accidentally may occur through a panel, instead of in-between the panels.

METHODS: We used three-dimensional optical coherence tomography to evaluate the location of distal main branch re-wiring through Tryton. Furthermore, we used computer simulations to evaluate the influence on stent geometry and mechanics.

RESULTS: Rewiring through a panel (instead of in-between two panels) occurred in 45% of the cases. By using virtual stent deployment, we found minimal differences in ostial side branch stenoses (44.8% in-between the panels and 39.0% through a panel). There were no differences in minimum stent areas of the distal main branch (6.38 mm2 vs. 6.39 mm2 ). In both scenarios, the re-wired Tryton cell was large enough for main branch stenting (expressed as the diameter of the largest possible circle that fits within the cells): 3.40 mm (in-between the panels) vs. 3.02 mm (through a panel).

CONCLUSIONS: In 45% of the Tryton implantations, distal main branch rewiring (and subsequent main branch stenting) was performed through one Tryton panel, instead of the assumed rewiring in-between the panels. However, this did not result in unfavorable stent geometries or mechanics, as evaluated with computer simulations.