Forward and back aspiration during ST-elevation myocardial infarction: a feasibility study

Aims: The inability to optimise stent expansion fully whilst simultaneously preventing distal embolisation during ST-elevation myocardial infarction (STEMI) remains a clinical conundrum. We aimed to describe a newly devised angiographic strategy of "forward" and "back" aspiration that leads to more complete thrombus removal and prevention of distal embolisation, to allow high-pressure post-dilatation of the implanted stent to be performed. Methods and results: Forward aspiration was conducted with a conventional aspiration thrombectomy catheter, with bail-out aspiration thrombectomy for angiographically persistent thrombus utilising the larger bore 6 Fr (0.056 '') guide catheter extension system (GuideLiner (R); Vascular Solutions, Inc., Minneapolis, MN, USA). Back aspiration was undertaken with a deeply intubated GuideLiner or guide catheter with a vacuum induced within, extending to the inflated angioplasty balloon, to allow for proximal embolic protection during balloon deflation during all stages of the PCI procedure, including high-pressure postdilatation of the stent to the visually estimated reference vessel diameter (RVD). Over a six-month period 30 consecutive cases were undertaken during working hours. Bail-out GuideLiner-assisted aspiration thrombectomy was performed in 9/30 cases because of inadequate thrombus removal with a conventional aspiration thrombectomy catheter. Back aspiration was performed in all cases. In 27/30 cases high-pressure post-dilatation of the stent was performed. The mean maximum post-dilatation balloon size and mean proximal reference vessel diameter did not significantly differ (3.60 +/- 0.41 mm vs. 3.65 +/- 0.45 mm, p=0.68). In all cases, implantation +/- post-dilatation of the stent to the visually estimated RVD was achievable without any deterioration in TIMI blood flow or myocardial blush grade. Conclusions: The strategy of forward and back aspiration to facilitate stent implantation and high-pressure post-dilatation during STEMI appears to be safe and effective. Randomised controlled trials are required to confirm the safety and efficacy of this newly devised angiographic strategy.