Lauren Peruski, DO

Maros ME, Brekenfeld C, Broocks G, Leischner H, McDonough R, Deb-Chatterji M, Alegiani A, Thomalla G, Fiehler J, Flottmann F, for the GSR Investigators. Number of Retrieval Attempts Rather Than Procedure Time Is Associated With Risk of Symptomatic Intracranial Hemorrhage. Stroke. 2021;52:1580–1588.

Endovascular therapies used to treat acute ischemic stroke are becoming increasingly common and effective. As more of these procedures are being conducted, we are becoming aware of the potential risks and complications associated with such treatments. Established adverse events include vessel dissection and/or perforation, cerebral vasospasm, clot migration with distal ischemia, and symptomatic intracerebral hemorrhage (sICH), among others. Of these, sICH in particular has been associated with poor outcomes and high mortality rates. Prior studies have concluded that >3 device passes correlates to increased sICH risk; however, procedure time was not properly adjusted for. Therefore, the data previously presented was confounded by time. This study was designed around the hypothesis that the number of retrieval attempts is positively associated with sICH regardless of procedure time.

The cohort described in this paper was collected from the German Stroke Registry – Endovascular Treatment (GSR-ET); this registry was created between 2015 and 2018. The adult patients included were required to have undergone endovascular therapy to treat an acute ischemic stroke caused by a large vessel occlusion of the anterior circulation. Those selected needed to have pre-specified data points within their chart (for example, Alberta Stroke Program Early CT Score, NIH Stroke Scale, Thrombolysis in Cerebral Infarction [TICI] score, 90-day Modified Rankin Scale [mRS], etc.). Patients were not included if they had an occlusion of the extracranial internal carotid artery (ICA), or an ICA occlusion proximal to the carotid terminus. Patients were also excluded if they required stent placement at the time of endovascular therapy, or if they experienced spontaneous recanalization at the time of angiography.

The main outcome examined was the occurrence of sICH. In this study, they used the ECASS II definition of sICH: Blood at any site in the brain on the CT scan (as assessed by the CT reading panel, independently of the investigator), documentation by the investigator of clinical deterioration, or adverse events indicating clinical worsening (e.g., drowsiness, increase of hemiparesis), or causing a decrease in the NIHSS score of 4 or more points. A secondary outcome was the occurrence of asymptomatic ICH confirmed by follow-up imaging within 24 hours of the procedure. The data was adjusted for baseline NIHSS, ASPECTS, TICI reperfusion, intravenous thrombolysis, and time to reperfusion.

In total, 593 patients met the criteria for this cohort. The patients that were included had a mean age of 72 years and were equally distributed with respect to gender. A majority had a history of hypertension, and nearly half had history of atrial fibrillation. The most common stroke etiology was cardioembolic. The median NIHSS on presentation was 15, and the median ASPECTS was 9. Intravenous thrombolysis was utilized in two-thirds. The median number of device passes was 2, with over 90% achieving TICI 2b/3 reperfusion.

The main finding of this study was that the risk of sICH increased in the setting of >3 retrieval attempts during endovascular thrombectomy; this was significant even when adjusted for procedure time. With respect to number of device passes, there was no significant correlation between asymptomatic intracerebral hemorrhages at 24 hours, however. Additionally, an ASPECTS score of 8 to 10 (as compared to ASPECTS scores < 8) was significantly protective against sICH. In clinical practice, the interventionalist should be aware of these risks and incorporate this knowledge into the decision to continue or terminate a procedure, especially in patients with large baseline core infarctions.