The risk of endovascular thrombectomy in acute ischemic stroke patients with large vessel occlusions harboring unruptured intracranial aneurysms

Abstract

Background and purpose: Endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) with large vessel occlusions (LVO) has significantly improved over the past decade. Unruptured intracranial aneurysms (UIAs) can potentially increase the risk of hemorrhage during EVT procedures. Given that limited data exist on this topic, this study investigated the safety of EVT in AIS patients with LVO who also harbor UIAs.

Methods: We analyzed prospectively collected data on consecutive AIS patients treated with EVT at a comprehensive stroke center in Southeast China between 2016 and 2023. Digital subtraction angiography (DSA) was routinely performed on all patients as part of the diagnostic workup. Angiograms were reviewed to determine aneurysm characteristics. The primary outcome measure was in-hospital intracranial hemorrhage (ICH) attributable to UIA rupture after EVT according to the Heidelberg classification system. Secondary outcomes included any in-hospital ICH, in-hospital symptomatic ICH [defined by European Australian Cooperative Acute Stroke Study (ECASS-3) criteria, i.e., National Institute of Health Stroke Scale (NIHSS) score increase ≥ 4 points], and favorable outcome [modified Rankin Scale (mRS) score 0-2] at 3-month follow-up. Additionally, we compared outcomes between patients who received both EVT and intravenous thrombolysis (IVT) and those who received EVT alone.

Results: Among 718 AIS patients with LVO treated with EVT, we identified 36 cases (5.0%) harboring a total of 42 UIAs. The mean diameter of UIAs was 4.16 ± 1.72 mm (range 1.5-9 mm), with 97.6% located in the anterior circulation and 52.4% in the target vessel of ischemic stroke. One patient (2.8%) treated with both EVT and IVT experienced symptomatic ICH (Heidelberg 1 and 3c) caused by aneurysm rupture. Any ICH occurred in 19 (52.8%) of the 36 patients, with 4 (11.1%) developing symptomatic ICH. At 3-month follow-up, 19.4% of patients had a favorable outcome. The rate of any ICH was significantly higher (71.4% vs. 26.7%, P = 0.008, Chi-squared test), while the rate of favorable outcome was lower in patients who received both EVT and IVT compared to those who received EVT alone (4.8% vs. 40%, P = 0.008, Chi-squared test).

Conclusions: Our findings indicate that EVT is relatively safe for AIS patients with LVO who also have UIAs. However, interventional physicians should carefully consider the procedural strategy, particularly when using IVT before EVT in these patients.

Keywords: Aneurysm; Endovascular thrombectomy; Intravenous thrombolysis; Ischemic stroke; Large vessel occlusions.

Fig. 1

Case 5 A 75-year-old woman with a history of hypertension presented with severe left-sided hemiparesis and a NIHSS score of 14. CTA angiography revealed a right proximal M2 MCA occlusion (A). The patient received intravenous alteplase 120 min after stroke onset, followed by mechanical thrombectomy. DSA confirmed the M2 occlusion and identified an aneurysm in the C6 segment (ophthalmic segment) of the ICA (B). The aneurysm is clearly visible on the post-treatment DSA image (C), indicated by the yellow arrow. D shows the Catalyst 6 catheter positioned at the terminal ICA, and panel E shows the Trevo SR deployed within the M2 segment of the MCA. Despite thrombectomy attempts with aspiration and the SR, successful recanalization of the occluded artery was not achieved. Following withdrawal of the devices, control angiography (F) revealed extravasation of contrast agent, suggesting a ruptured aneurysm. Dyna-CT confirmed hemorrhagic transformation and SAH (G & H). The patient declined treatment of the aneurysm with coil embolization. At the 3-month follow-up, the patient’s mRS score was 5, indicating severe disability