Adjustment of Stent Retriever Length to Clot Extent Affects First-Pass Reperfusion in Endovascular Treatment of Acute Ischemic Stroke

Abstract

Background: Stent retriever technology has evolved, and significantly longer devices have become available for mechanical thrombectomy (MT) of large cerebral vessel occlusions in ischemic stroke. We hypothesized that increased stent retriever length may improve the rate of complete angiographic reperfusion and decrease the respective number of attempts, resulting in a better clinical outcome. Methods: Retrospective analysis of patients with large vessel occlusion in the anterior and posterior circulation treated with stent retriever MT. The study group was dichotomized into short (20 mm) and long (>20 mm) retrievers using propensity matching. In the anterior circulation, the clot burden score was evaluated. Primary end points were first-pass modified thrombolysis in cerebral infarction (mTICI) 3 reperfusion and first-pass mTICI ≥ 2b reperfusion, and the secondary end point was functional independence (defined as modified Rankin Scale score 0-2) at discharge and 90 days. Results: Overall, 394 patients were included in the analysis. In the anterior circulation, short stent retrievers had a significantly higher rate of first-pass reperfusion in cases with low clot burden (mTICI 3: 27% vs. 17%; p = 0.009; mTICI ≥ 2b: 42 vs. 30%; p = 0.005) and in middle cerebral artery occlusions (mTICI ≥ 2b: 51 vs. 41%; p = 0.024). Higher rates of favorable outcome at discharge and 90 days were observed for the short stent retriever group (p < 0.001). Conclusion: Stent retriever length should be adjusted to clot burden score and vessel occlusion site.

First-Pass Reperfusion by Mechanical Thrombectomy in Acute M1 Occlusion: The Size of Retriever Matters

“…On the contrary, comparing lengths of stents (short: 4 × 20 mm and long >20 mm: 4 × 40, 6 × 30, or 4 × 30), Styczen et al (17) found comparable FP TICI 3 for both short and long stent retrievers in MCA (50.8 vs. 40.7%) occlusions with higher mFP in short vs. long stent retrievers (50.8 vs. 40.7%, p = 0.024). But long retrievers achieved a higher rate of successful reperfusion (TICI ≥2b) with higher rate of SAH.…”

“…In vitro , it was reported that longer stent retrievers (6 × 40 vs. 6 × 30) achieve higher FP in fibrin-rich clots ( 15 ). On the contrary, one study comparing diameter (4 vs. 6 mm) found no difference in reperfusion rate of ICA, MCA, and anterior cerebral artery (ACA) occlusions ( 16 ), and others found higher rates of modified FP (mFP) (TICI ≥2b) in the MCA with short stent retrievers (20 mm vs. others) ( 17 ).…”

Evaluation of effectiveness and safety of the large-format pRESET 6-50 thrombectomy stent-retriever in the endovascular treatment of ischemic stroke: real-world experiences from two tertiary comprehensive stroke centers

“…Thus, in LVO, the largest possible stent-retriever should be chosen for the first thrombectomy attempt (25,27).…”

Enhancing the First-Pass Effect in Acute Stroke: The Impact of Stent Retriever Characteristics

“…Angiographic revascularization was assessed using the modified thrombolysis in cerebral infarction (TICI) score in the final run of the angiography, measuring reperfusion in the downstream territory of the specific arterial occlusion, as follows: grade 0 = no reperfusion; grade 1 = antegrade reperfusion past the initial occlusion, but with limited distal branch filling and little or slow distal reperfusion; grade 2a = antegrade reperfusion of less than half of the occluded target artery previously ischemic of the downstream territory; grade 2b = antegrade reperfusion of more than half, but <90% complete antegrade reperfusion; grade 2c = near-complete reperfusion (90–99%) except for slow flow in a few distal cortical vessels or the presence of small distal cortical emboli; and grade 3 = complete antegrade reperfusion with the absence of visible occlusion in all distal branches [ 14 , 18 , 23 , 24 , 25 , 26 ].…”