Fig. 1

The first procedure. a-b On Sep 2, 2020, emergent head NCCT revealed new infarctions in the right internal watershed area. (a. red arrows), head CTP showed an ischemic penumbra of 100.3 mL in the bilateral ICAs (green area). c-h Emergent EVT on Sep 3, 2020: Preprocedural angiogram showed long stenosis with a double lumen sign, distal to the right carotid bulb (c. red arrows indicated a flow-limiting segment), string-like stenosis distal to the left carotid bulb (d. red arrows indicated a flow-limiting segment) with an opening into left PCom A (e. red arrow); The microcatheter was in the true lumen, which was confirmed by post-lesion angiography (f. red arrow); A 6 × 30 mm Solitaire FR stent was temporarily deployed in the key flow-limiting segment through a microcatheter (g. red arrows indicated the distal and proximal markers of the stent); After the stent release, angiogram showed that the stenosis of the lesion was reduced, the double-lumen sign disappeared, the anterior blood flow was significantly improved, and a small amount of compensation was made to the left anterior circulation through ACom A (h). i-j On Sep 4, 2020, repeated head NCCT revealed more pronounced infarctions than the pre-procedure status (red arrows), head CTP showed that the perfusion of the blood supply area of the right ICA was recovered, and the penumbra of the blood supply area of left ICA was enlarged to 114.2 mL, compared with that before the procedure (green area)