Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features

 So everything here was a failure, nobody got to 100% recovery! Damn it all, that is the only goal in stroke that survivors want! GET THERE!

Comparing Outcomes of Thrombectomy Versus Intravenous Thrombolysis Based on Middle Cerebral Artery M2 Occlusion Features

Huan Zhou,

Wansi Zhong,

Tingxia Zhang,

Chenghua Xu,

Genlong Zhong,

Guomin Xie,

Bing Zhang,

Hongfang Chen,

En Wang,

Dongjuan Xu,

Chaochan Cheng,

Jiansheng Yang,

Min Lou,

… See all authors

Originally published24 May 2024https://doi.org/10.1161/STROKEAHA.123.044986Stroke. 2024;55:1592–1600

Abstract

BACKGROUND:

Current evidence provides limited support for the superiority of endovascular thrombectomy (EVT) in patients with M2 segment middle cerebral artery occlusion. We aim to investigate whether imaging features of M2 segment occlusion impact the effectiveness of EVT.

METHODS:

We conducted a retrospective cohort study from January 2017 to January 2022, drawing data from the CASE II registry (Computer-Based Online Database of Acute Stroke Patients for Stroke Management Quality Evaluation), which specifically documented patients with acute ischemic stroke presenting with M2 segment occlusion undergoing reperfusion therapy. Patients were stratified into the intravenous thrombolysis (IVT) group (IVT alone) and EVT group (IVT plus EVT or EVT alone). The primary outcome was a modified Rankin Scale score 0 to 2 at 90 days. Secondary outcomes included additional thresholds and distribution of modified Rankin Scale scores, 24-hour recanalization, early neurological deterioration, and relevant complications during hospitalization. Safety outcomes encompassed intracranial hemorrhagic events at 24 hours and mortality at 90 days. Binary logistic regression analyses with propensity score matching were used. Subgroup analyses were performed based on the anatomic site of occlusion, including right versus left, proximal versus distal, dominant/co-dominant versus nondominant, single versus double/triple branch(es), and anterior versus central/posterior branch.

RESULTS:

Among 734 patients (43.3% were females; median age, 73 years) with M2 segment occlusion, 342 (46.6%) were in the EVT group. Propensity score matching analysis revealed no statistical difference in the primary outcome (odds ratio, 0.860 [95% CI, 0.611–1.209]; P=0.385) between the EVT group and IVT group. However, EVT was associated with a higher incidence of subarachnoid hemorrhage (odds ratio, 6.655 [95% CI, 1.487–29.788]; P=0.004) and pneumonia (odds ratio, 2.015 [95% CI, 1.364–2.977]; P<0.001). Subgroup analyses indicated that patients in the IVT group achieved better outcomes(NOT RECOVERY!) when presenting with right, distal, or nondominant branch occlusion (P_{all interaction}<0.05).

CONCLUSIONS:

Our study showed similar efficiency of EVT versus IVT alone in acute M2 segment middle cerebral artery occlusion. This suggested that only specific patient subpopulations might have a potentially higher benefit of EVT over IVT alone.

REGISTRATION:

URL: https://clinicaltrials.gov; Unique identifier: NCT04487340.

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Five randomized clinical trials issued in 2015 have confirmed the superiority of endovascular thrombectomy (EVT) over medical management in patients of acute ischemic stroke (AIS) with anterior large vessel occlusion.^1–5 However, patients with AIS enrolled in these trials mainly suffered from proximal large vessel occlusion, including internal carotid artery and M1 segment middle cerebral artery (MCA). In a meta-analysis of individual patient data from the above trials, only 95 patients were finally identified as M2 segment MCA occlusion,⁶ resulting in limited evidence for the efficacy of EVT in this subgroup.⁷

In previous post hoc studies, EVT was considered an effective measure that could improve(NOT GOOD ENOUGH!) clinical outcomes in acute M2 occlusion, when compared with the control group who received medical management, that is, intravenous thrombolysis (IVT) or antiplatelet therapy if IVT is not applicable.^8–10 However, patients with AIS with M2 occlusion who received EVT achieved similar functional outcomes when compared with those with IVT alone,¹¹ which might be due to a potentially beneficial treatment effect of IVT on more distal clot locations.¹²

Some M2 segment is the dominant artery supplying blood to a large portion of the MCA territory, presenting as severe neurological impairment and sizable infarction after occlusion, but is as easily accessible for EVT as the M1 segment.^13–15 Hence, patients with the clot situated in the dominant M2 artery or in close proximity to the furcation are likely to experience similar benefits from EVT. We hypothesized that imaging features of M2 segment MCA occlusions might affect the efficacy and safety of EVT, either with or without IVT. In the current study, we sought to investigate whether certain anatomic characteristics of M2 segment occlusions such as location, size, anatomy, and number of vessels occluded could help select patients who would benefit more from EVT than IVT alone.