Contact Aspiration Combined with a Stent Retriever versus Contact Aspiration Alone in Mechanical Thrombectomy for Acute Ischemic Strokes: A Nationwide Analysis Using the Diagnosis Procedure Combination Database

Saki Nakashima; Shuhei Egashira; Shotaro Aso; Hideo Yasunaga; Kenichiro Sato; Yoshiki Niimi; Toshiaki Isogai; Hiroki Matsui; Yuichiro Shirota; Masashi Hamada; Kiyohide Fushimi; Tatsushi Toda; Satoshi Kodama

doi:10.5797/jnet.oa.2025-0105

Contact Aspiration Combined with a Stent Retriever versus Contact Aspiration Alone in Mechanical Thrombectomy for Acute Ischemic Strokes: A Nationwide Analysis Using the Diagnosis Procedure Combination Database

J Neuroendovasc Ther. 2025;19(1):2025-0105. doi: 10.5797/jnet.oa.2025-0105. Epub 2025 Oct 15.

Authors

Saki Nakashima¹, Shuhei Egashira², Shotaro Aso³, Hideo Yasunaga⁴, Kenichiro Sato^{5

6}, Yoshiki Niimi^{5

6}, Toshiaki Isogai^{3

7}, Hiroki Matsui⁴, Yuichiro Shirota^{1

8}, Masashi Hamada¹, Kiyohide Fushimi⁹, Tatsushi Toda¹, Satoshi Kodama¹⁰

Affiliations

¹ Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
² Department of Neurology, Toranomon Hospital, Tokyo, Japan.
³ Department of Health Services Research, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
⁴ Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
⁵ Unit for Early and Exploratory Clinical Development, The University of Tokyo Hospital, Tokyo, Japan.
⁶ Dementia Inclusion and Therapeutics, The University of Tokyo Hospital, Tokyo, Japan.
⁷ Department of Cardiology, Tokyo Metropolitan Tama Medical Center, Tokyo, Japan.
⁸ Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
⁹ Department of Health Policy and Informatics, Institute of Science Tokyo Graduate School, Tokyo, Japan.
¹⁰ Department of Neurology, The University of Iowa Hospitals and Clinics, Iowa, IA, USA.

Abstract

Objective: The technique combining a stent retriever (SR) and contact aspiration (CA) has been widely used in mechanical thrombectomy for acute ischemic stroke. However, advancements in large-bore aspiration catheters suggest that CA alone may achieve comparable therapeutic outcomes, while streamlining the procedure. Nevertheless, real-world evidence directly comparing these approaches is limited.

Methods: We identified patients hospitalized for ischemic stroke who underwent mechanical thrombectomy between April 2020 and March 2023 from the Japanese national inpatient Diagnosis Procedure Combination database. Patients treated with CA or CA combined with SR (CA + SR) were enrolled. Propensity score overlap weighting was performed to adjust for confounders. The outcomes were intracranial hemorrhage (ICH), functional independence at discharge, in-hospital mortality, and total hospitalization cost.

Results: Among 17589 eligible patients, 14892 underwent CA + SR and 2697 received CA. The adjusted proportions of ICH were comparable between the groups (1.4% vs. 1.3%; adjusted risk difference [aRD], 0.1%; 95% confidence interval [CI], -0.5% to 0.5%). The CA + SR group had a lower proportion of functional independence at discharge (28.7% vs. 36.2%; aRD, -7.5%; 95% CI, -9.5% to -5.4%) and higher in-hospital mortality (11.4% vs. 9.2%; aRD, 2.2%; 95% CI, 1.0%-3.5%). The total hospitalization costs (USD) were higher in the CA + SR group than in the CA group (21687 vs. 18317; difference, 3370; 95% CI, 2976-3764).

Conclusions: The proportion of patients with ICH did not differ significantly between the CA + SR group and CA groups. CA + SR was associated with worse functional outcomes, higher in-hospital mortality, and higher costs.

Keywords: acute ischemic stroke; combined techniques; contact aspiration; direct aspiration; thrombectomy.