Export aspiration catheter

Potential strategies to treat the lesions due to stent failure were decided by the operators. Manual aspiration thrombectomy (Export aspiration catheter; Medtronic, Santa Rosa, CA, USA) before OCT imaging in patients with a sizable occlusive thrombus or TIMI flow grade <2 was allowed. Stent failure included ISR and stent thrombosis. ISR was either ≥50% luminal narrowing at follow-up angiography with symptoms or signs of ischemia (at rest or with stress) or ≥70% luminal narrowing at follow-up angiography without clinical symptoms or signs. Definite stent thrombosis was defined according to the Academic Research Consortium criteria.^{10 (link)}Coronary angiography at the time of stent failure was performed using guiding catheters after intracoronary injection of 100–200 μg of nitroglycerin. Angiographic images were analyzed using CAAS 5.10.1 software (Pie Medical Imaging BV, Maastricht, the Netherlands) at the intravascular imaging and physiology core lab in the Second Affiliated Hospital of Harbin Medical University. Lesions’ location and length, minimal lumen diameter (MLD), diameter stenosis (DS), and initial and post-procedure TIMI flow were measured by an independent investigator (T.C.) who was blinded to clinical and OCT data. Detailed analytical methods were mainly referred to previous studies.^{11 (link),12 (link)}

After OFDI, an Export aspiration catheter (Medtronic) was guided using a 0.014-inch guidewire, and an angioscopic catheter was inserted into its aspiration lumen and guided distal to the stent. The vascular lumen was examined while keeping the intra-stent lumen blood free by continuous and manual infusion of saline. The accumulated images were stored on a hard disc. An off-line qualitative analysis regarding the mobility of protruded plaques was performed (grade 1: no mobility, grade 2: blood flow-related mobility, and grade 3: marked mobility/rupture). Grade 3 patients were regarded as having significantly mobile plaque protrusion.

The use of platelet inhibitors or anticoagulants was left to the discretion of the treating physician. After the restoration of antegrade flow, administration of intracoronary nitrates was encouraged. Stenting was encouraged with optional postdilatation. For patients randomized to thrombus aspiration, guidewire placement was followed by thrombus aspiration with a manual aspiration catheter. In lesions that could not be passed through, predilating was permitted with the smallest possible angioplasty balloon to a nominal diameter size of 2.0 mm. Thrombus aspiration catheters were required to be 6-F compatible, low profile in design, and intended for manual aspiration. The following catheters were recommended but other catheters fulfilling the criteria were allowed: Eliminate (Terumo; crossing profile, 0.068 in.), Export Aspiration Catheter (Medtronic; 0.067 in.), and Pronto extraction catheter (Vascular Solutions; 0.070 in.).14 (link) Direct stenting, stent type, postdilatation, and duration of P2Y12 inhibitor treatment was at physician discretion, while lifelong acetylsalicylic acid was recommended.