最終健常確認から6時間以上経過した急性期脳梗塞に対する脳血栓回収療法の検討

抄録

Thrombectomy is currently recommended for eligible patients with acute stroke who are treated within 6 hours of onset. However, wake-up stroke or stroke with an unclear onset of symptoms is known to occur in approximately 25% of all patients diagnosed with ischemic stroke. Acute stroke with unknown time of onset or onset more than 6 hours prior to detection is not considered for thrombectomy because the effectiveness is uncertain. However, recent trials of endovascular treatment for acute ischemic stroke more than 6 hours after onset have been successful due to the use of accurate perfusion imaging of the penumbral region of tissue, calculated using an automated image post-processing system. In this study, we determined the efficacy and safety of endovascular treatment in patients with acute ischemic stroke onset of more than 6 hours, in whom the indications for thrombectomy had been determined by the mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR).

We reviewed the clinical records of 29 consecutive patients who underwent thrombectomy for acute ischemic stroke between January 2016 and December 2017. Of the 29 patients, 9 had presented more than 6 hours after stroke onset, and 20 had presented within 6 hours. The indication for thrombectomy was decided using DWI-FLAIR mismatch, which was defined as a new hyperintense lesion on DWI without any hyperintense signal change on FLAIR. The rates of favorable outcome and mortality at discharge, recanalization rate, and symptomatic intracranial hemorrhage did not differ significantly between the two groups.

In conclusion, with the use of DWI-FLAIR mismatch, thrombectomy for acute strokes detected more than 6 hours after onset appears to be as safe and efficient as thrombectomy for strokes detected within 6 hours of onset.