Guide wire thrombus formation during trans-femoral TAVI.

The Amplatz super-stiff (SS) guidewire (Boston Scientific, MA, USA) is commonly used and routinely modified in shape during TAVI. The intention is to form a ‘curvature’ at the 3.5 cm flexible tip to reduce the risk of left ventricular myocardial perforation during catheter manipulations and valve delivery. We report 2 cases of distal guide wire thrombus formation that occurred on areas of the wire that had been manipulated in shape (Figs. 1 and 2). Both were visualised by intraprocedure TOE and occurred despite an activated clotting time (ACT) greater than 300 seconds prior to wire placement, pre-treatment with dual anti-platelet therapy (aspirin and clopidogrel 75 mg daily) and regular aspiration/flushing of the 18 Fr introducer sheath. Both patients had extensive other co-morbidities, including significant left ventricular systolic dysfunction, and had both been declined surgical aortic valve replacement. The sequence of our trans-femoral TAVI is consistent -we introduce the18Fr sheath over the SSwire placed in the thoracic aorta, then remove the SSwire,flush the 18Fr sheath side arm and then cross the aortic valve with a catheter (usually AL1), exchange for a pigtail catheter and thenposition the SSwire through the pigtail catheter (with careful live TOE to check the wire position).