Impact of Number of Passes Before Rescue Therapy in Thrombectomy for Basilar Artery Strokes

When standard endovascular thrombectomy techniques fail to achieve a successful recanalization, it is often necessary to use rescue therapies (RTs). RTs are more commonly used in basilar artery occlusions and conventionally thought to represent "a last resort option." We sought to study the outcomes of basilar artery occlusion patients who received RT, and further hypothesize that the number of instrumental passes before initiation of RT may be associated with increased risk for poor clinical outcomes.

We performed a retrospective analysis of the ETIS ("Endovascular Treatment in Ischemic Stroke") registry. Our primary analysis included 277 patients who underwent thrombectomy for basilar artery occlusion, of whom 74 patients (26.7%) who received RT, defined as the use of intra-arterial drugs, angioplasty, or stenting. Primary outcome measures included successful or complete reperfusion (final modified thrombolysis in cerebral infarction ≥2b or 3), functional independence (modified Rankin scale of 0-2), and mortality at 3 months.

RT patients were more likely to have an atherosclerotic cause than non-RT patients (46/74 [62.2%] versus 38/203 [18.7%]), were more likely to die (42/74 [56.8%] versus 73/203 [36.0%]), and were less likely to achieve functional independence (12/74 [16.2%] versus 84/203 [41.4%]). In the RT cohort, 17 of 74 patients (23.0%) had 1 pass before RT initiation, and 8 of 17 (47.1%) achieved a modified Rankin scale score of 0 to 2 at 3 months, with a mortality rate of 23.5% (4/17). The chance of achieving good clinical outcome decreased with each additional pass, whereas mortality increased. The odds of mortality at 3 months were highest in the >3 passes group, with an odds ratio of 10.29 (95% CI, 2.42-43.81) compared with 1 pass. None of the 25 patients with >3 passes before RT achieved 3-month functional independence.

There is a significant correlation between the number of passes before initiation of RT and 3-month clinical outcomes in basilar artery occlusion patients.