Abstract TP22: Stent Retriever Diameter and Impact on Reperfusion Rates in Intracranial Carotid Occlusions

Background: The impact of oversized stent-retrievers in reperfusion rates during thrombectomy is unclear. Devices matching the vessel diameter may lead to proportionally larger cells and facilitate device-clot integration. We aim to evaluate if the device diameter may impact reperfusion rates in stroke thrombectomy. Methods: This is a retrospective analysis of a prospectively collected database from a single comprehensive stroke center. We included patients with intracranial carotid occlusions in which stent-retrievers (Trevo or Solitaire devices) were used as the first strategy, from September 2010-March 2017, and compared the 4mm vs 6mm diameter groups. 3mm devices and other retriever-like devices were excluded. Primary outcome was first pass reperfusion (modified TICI2b-3 with the first device pass). Results: Of the 1204 thrombectomies performed within the study period, 150 met inclusion criteria (Trevo: 64/Solitaire: 86/6mm device:67 /4mm: 83). Age, gender, comorbidities and the use of IV tPA were comparable between groups. NIHSS was similar between the 4mm vs 6mm devices (19[14-22] vs 18.5[14-22];p=0.64), as well as time from last normal to puncture (403[260-626] minutes vs 344 [209-816];p=0.54), and ASPECTS (7[6-9] vs 8[7-9];p=0.25), respectively. Patients with 4mm devices had less tandem disease (11% vs 28%,p=0.01). The use of local aspiration was similar between groups (7vs9%p=0.76) for the 4mm and 6mm devices. First-pass mTICI2b-3/mTICI3 reperfusion was achieved in similar proportion between the 4mm vs 6mm groups: 52%vs.56%;p=0.62 / 32%vs22%;p=0.20, respectively. Parenchymal hematomas (16% vs 9%;p=0.22) and subarachnoid hemorrhage (5% vs 7%;p=0.74) were similar between the 4mm and 6mm arms. Independent outcome at 3months was more common in the 4mm vs 6mm groups (28%vs50%;p=0.03). Multivariable analysis indicated mRS0-2 at 90-days independently associated with first-pass reperfusion and demonstrated no impact of device diameter on first-pass reperfusion. Conclusions: The use of 6mm stent retrievers for intracranial carotid occlusions had demonstrated benefit over 4mm devices for chances of first pass reperfusion.