Longer stent retrievers were found independently associated with higher rates of first-pass reperfusion and should be favoured over their shorter counterparts in light of their safety profile. Diogo Haussen presented these findings at the International Stroke Conference (ISC; 24–26 January 2018, Los Angeles, USA). The study also showed that despite the additional cost, local thromboaspiration as adjunct to combined balloon guide catheter and stent retriever thrombectomy improved thrombectomy performance.
Stent retrievers have revolutionised stroke treatment since their introduction and refinements in the technology and techniques are a very importance facet of thrombectomy research. Longer stent retrievers have become available more recently and they have theoretically advantages over their shorter devices, such as higher area of device-thrombus interaction, lower chance of missing the target site, and an improved ability to drag the clot out if clot-device integration fails.
The group from Emory University School of Medicine and The Marcus Stroke and Neuroscience Center (Atlanta, USA), including Diogo Haussen and Raul Nogueira, set out to evaluate if and how device length impacts reperfusion rates in stroke thrombectomy. They carried out a retrospective analysis of prospectively collected single institution data from June 2011 until March 2017. To be included, an 4 mm diameter stent retriever had to be used as the first line strategy in conjunction with balloon guided catheter to treat intracranial internal carotid artery, middle cerebral artery main stem (M1) and middle cerebral artery M2 occlusions. Laser-cut, closed cell nitinol stent retrievers (Solitaire [Medtronic neurovascular, Minneapolis, USA], Trevo [Stryker neurovascular, Fremont, USA]) were used.
The population was split into two groups. The first was treated with long (Trevo 4x30mm / Solitaire 4x40mm) stent retrievers and the second was treated with short retrievers (Trevo 4x20mm / Solitaire 4x20mm). The primary outcome was first pass reperfusion (modified TICI 2b–3 after first pass).
There were 1126 thrombectomies within the study period and 420 of them were included in the study. Of those, 221 (53%) were treated with long stent retrievers and 199 (47%) were treated with short stent retrievers. First pass reperfusion was achieved in 138 (62%) of patients in the long retriever arm compared to 50% (178) of patients in the short retriever group. The results remained markedly significant after adjustment for potential confounders (OR 2.21; 95% CI 1.36-3.60; p=0.001).