Optimal balloon positioning to maximize the proximal optimization technique (POT)

Abstract

Proximal optimizing technique (POT) is largely recommended to improve the global malapposition and the side branch (SB) obstruction (SBO). It is classically recommended to position the POT balloon as obtain the distal radio opaque marker at the carina cut plan. However, the real impact of the balloon position is unknown. SynergyTM stents were implanted on left main fractal coronary bifurcation bench models. Initial POT were performed in 3 positioning ( n = 5 per group) as obtain the loose of the balloon parallelism 1 mm before the carina cut plan (proximal), at the carina (medium) and 1 mm after (distal). Final results were quantified on 2D- and 3D-OCT. Compared to the implantation alone, initial POT improved the malapposition in all position (proximal: 64.5 ± 1.4% vs. 5.1 ± 2.7%, medium: 60.2 ± 2.4% vs. 1.3 ± 0.6%, final: 60.5 ± 2.9% vs. 1.1 ± 1.8%, P < 0.05 for all). However the residual malapposition was higher in proximal position compared to the others ( P < 0.05). Proximal POT failed to improve also the final SBO like medium or distal POT ( P < 0.05). On the contrary, distal POT overstretched the proximal part of the main branch illustrated by a stent artery-ratio at 1.22 ± 0.04 vs. 1.11 ± 0.07 in medium POT ( P < 0.05) ( Table 1 ). More than the position of distal radio opaque marker, it seems that the loose of balloon parallelism positioning is essential to obtain the maximum of POT's benefit. A balloon positioning just at the carina cut plan obtain the optimal mechanical final result.