The purpose of this monocentric retrospective study is to compare, in patients with acute distal vessel occlusion stroke, the early rates of successful recanalization in patients treated with Alteplase (ALT) versus Tenecteplase (TNK), based on a retrospective analysis of magnetic resonance imaging (MRI) performed early after IVT.

Early rates of successful recanalization (SR) of distal vessel occlusions (DVO) following intravenous thrombolysis (IVT) between alteplase (ALT) and tenecteplase (TNK) are poorly known.

From March 2016 to February 2020, consecutive stroke patients hospitalized in the stroke unit of the Sud-Francilien Hospital with DVO identified on baseline MRI and suitable for IVT but not for mechanical thrombectomy will be included. In our stroke unit, patients were treated with ALT, 0.9 mg/kg from March 2016 to February 2018 and then with TNK, 0.25 mg/kg from March 2018 to December 2023. MRI was controlled 1-2 hours within IVT (MRI-2). Early recanalization was assessed on an adapted Arterial Occlusion Lesion (AOL) scale, SR being defined as AOL 2/3 scores on MRI-2. The rate reduction of thrombus length (TL) when thrombus persisted, the IVT response threshold of TL and the infarct size evolution were also assessed. In the present study, the investigators sought to compare early rates of SR between the two lytics, based on a retrospective analysis of magnetic resonance imaging (MRI) performed early after IVT.

Inclusion Criteria:

• Age≥ 18 years.

• Acute ischemic stroke (visible on DWI, but not visible on FLAIR) on initial MRI associated with distal arterial occlusion as defined below:

  • A distal occlusion of the M2 segment of the middle cerebral artery (MCA)
  • Occlusion (regardless of location) of a non-dominant M2 branch of the MCA
  • Occlusion of the M3 segment of the MCA.
  • Occlusion of the A2 or A3 segment of the anterior cerebral artery (ACA)
  • Occlusion of the P2 or P3 branch of the posterior cerebral artery (PCA).
  • A proximal M2-MCA or proximal P1-PCA occlusion may also be included if not eligible for mechanical thrombectomy, especially if the initial NIHSS score is low (<5).
  • Distal arterial occlusion is identified by MRI either on the TOF (Time of Flight)-ARM sequence and/or on the presence of a thrombus (Susceptibility Vessel sign, SVS) on the SWAN sequence,

• IVT by ALT or TNK within 4H30 after onset of symptoms,

• Early brain MRI performed 1 to 2 hours after IVT (MRI n°2),

• Good quality MRI (absence of motion artifact interfering with interpretation) with availability of DWI, FLAIR, TOF-MRA and SWAN sequences.

Exclusion Criteria:

- Patients informed of the study who objected to the collection of their data.

This is a monocentric retrospective study (Sud-Francilien Hospital (SFH), Corbeil-Essonnes, France) based on a stroke registry prospectively gathered.

From March 2016 to February 2020, consecutive patients with acute ischemic stroke (AIS) assessed on brain MRI and treated with IVT alone who fulfilled the following criteria will be included: 18 years or older; evidence of an AIS on acute MRI (MRI-1) associated with a distal vessel occlusion as defined below; IVT within 4h30 of symptoms onset; availability of a post-IVT MRI within 1-2 hours (MRI-2); good quality of MRI sets including SWAN images.