Novel aspiration catheter design for acute stroke thrombectomy.

BACKGROUND: Navigable, large diameter aspiration catheters demonstrate markedly improved recanalization rates over smaller lumen devices in suction embolectomy. We evaluated the performance of a novel aspiration catheter system designed to maximize lumen size, and compare it to other commercially available aspiration catheters. METHODS: The 6F R4Q aspiration catheter system comprises a proximal pusher wire of 117 cm length connected to a distal catheter of 25 cm length. When placed through standard guide catheters and into the cerebral circulation, the proximal catheter makes a tight seal between its outer surface and the guide catheter's inner surface. During aspiration, in vitro flow rates and tip suction force under gentle retraction were compared among 10 commercially available aspiration catheters and the R4Q system. RESULTS: The R4Q 6F, 5F, 4F, and 3F catheters achieved flow rates at least 21.9%, 24.7%, 61.9%, and 244.7% greater than the other catheters tested respectively and the R4Q 6F produced a 140.2% higher tip force than a catheter of similar size. Fluid flow rate in the R4Q 6F increased on retraction into the guide catheter, delivering a 58.2% increase from fully extended to fully retracted. CONCLUSION: The R4Q design demonstrates a substantial increase in aspirated flow rate and suction force due to an increased effective diameter than standard tubular catheter designs tested. The prominent increase in the aspiration parameters measured in vitro supports the potential for improved clinical results during stroke thrombectomy procedures.

Drug-eluting tibial stents: objective patency determination.

PURPOSE: Endovascular management of limb-threatening ischemia often requires treatment of tibial occlusive disease. This study was preformed to examine the patency of drug-eluting tibial stents. MATERIALS AND METHODS: The medical records of all patients undergoing drug-eluting tibial stent placement for limb-threatening ischemia from June 2004 to June 2008 were retrospectively reviewed. Postprocedural antiplatelet therapy included clopidogrel and aspirin. Patients were followed with serial arterial duplex ultrasonography and had selective subsequent angiographic evaluation based on noninvasive findings. Primary patency of the target lesion, limb salvage, and survival rates were reported. RESULTS: A total of 240 patients underwent 283 tibial angioplasty procedures to treat limb-threatening ischemia during the 4-year period. Fifty-two patients (22%) had a suboptimal balloon result and were treated with a drug-eluting tibial stent. Balloon-expandable paclitaxel-eluting stents were used in all patients (1.2 stents per patient; range, 1-3; median diameter, 2.75 mm; range, 2.5-3.5 mm; median length, 24 mm; range, 20-32 mm). Forty-eight of those 52 patients (92%) had simultaneous endovascular treatment of proximal lesions. Mean follow-up was 14.3 months (range, 1-48 months). Target lesion patency of the drug-eluting tibial stent was 73% at 24 months (SE < 10%). Limb salvage rate in patients treated with drug-eluting tibial stents was 86% at 26 months (SE < 10%), and the survival rate was 65% at 24 months (SE < 10%). CONCLUSIONS: Drug-eluting tibial stents are a viable option for the endovascular management of limb-threatening ischemia and have acceptable patency rates. The majority of patients require multilevel endovascular treatment, and close surveillance is required for limb salvage.