A Novel Endovascular Therapy Strategy for Acute Ischemic Stroke Due to Intracranial Atherosclerosis-Related Large Vessel Occlusion: Stent-Pass-Aspiration-resCuE-Micowire-Angioplasty (SPACEMAN) Technique

Abstract

Background: There is no clear consensus on the optimal endovascular treatment strategy for patients with ischemic stroke caused by ICAS-related large vessel occlusion (LVO). SPACEMAN, a novel thrombectomy technique that entails passing an aspiration catheter over the stent retriever and then retaining the microwire for angioplasty, has not been described. The aim of this prospective study was to evaluate our initial application of SPACEMAN and compare this technique with the Solumbra technique.

Methods: Forty-four consecutive patients with acute ischemic stroke resulting from ICAS-related LVO were randomly divided into two groups: Solumbra group (n = 22) and SPACEMAN group (n = 22). Demographic and clinical data were prospectively collected. Modified Rankin Scale (mRS) score of ≤ 2 of anterior circulation and mRS score ≤ 3 of posterior circulation at 3 months post-discharge was regarded as good prognosis.

Results: The SPACEMAN group showed reduced mean time from femoral access to recanalization compared with the Solumbra group (39.55 ± 10.63 min vs. 50.73 ± 9.89 min, P = 0.001). The overall recanalization rate in the entire cohort was 93.18% (41/44). At 3-month follow-up, the overall good prognosis rate was 47.73%; 13 patients (59.09%) in the SPACEMAN group and 8 (36.36%) in the Solumbra group showed good prognosis. One patient in the SPACEMAN group (4.55%) and two patients in the Solumbra group (9.09%) developed symptomatic intracranial hemorrhage. The overall mortality rate was 4.55% (2/44).

Conclusions: This study suggests that SPACEMAN exhibits a shorter operation revascularization time than the standard thrombectomy. Complications and prognosis were comparable between the two groups. The safety and efficacy of this novel technique need to be studied in larger patient series.

Keywords: SPACEMAN; Solumbra; endovascular therapy; intracranial atherosclerosis; large vessel occlusion.

Figure 1

Patient flow diagram.

Figure 2

➀-➅ Schematic illustration of the SPACEMAN technique. ➀ The stent is deployed and the aspiration catheter is placed to the thrombus. ➁ The aspiration catheter is placed through the thrombus over the distal tip of stent retriever. ➂ The stent retriever is removed under negative suction without changing the position of the aspiration catheter. ➃ A 300 cm microwire is steered through the occlusion lesion to the distal segment under the guidance of the aspiration catheter. ➅ Angiography performed after the aspiration catheter is withdrawn proximal to the occlusion. ➆ Angioplasty of balloon or stent is performed.

Figure 3

A 49-year-old man was admitted due to left limb numbness 12 h ago and left limb paralysis 6 h ago. NIHSS: 10.➀ Head DWI: watershed infarction of the right hemisphere; ➁ DSA: right MCA M1 initial part occlusion; ➂ SPACEMAN technique: (A) The aspiration catheter was placed near the occlusion segment and the stent retriever was released after verification of true vascular cavity by the microwire. (B) The aspiration catheter was placed through the thrombus over the stent retriever forming manual negative pressure. Once the aspiration catheter reached the end of the stent retriever (Figure 2➁), the stent retriever was then withdrawn under continuous negative pressure. (C) A 300 cm microwire was placed at MCA M2 distal segment under the guidance of the aspiration catheter. (D) Angiography was performed after the aspiration catheter was withdrawn proximal to the occlusion and showed severe M1 stenosis. (E) The balloon-expandable stent was delivered to the stenotic segment under the guidance of the aspiration catheter. (F) DSA performed after angioplasty showed complete recanalization.