PMC8446545_01
Endovascular treatment of V4 segment occlusion of the right vertebral artery. (A) Computed tomography angiography revealed occlusion of the V4 segment of the right vertebral artery without calcification of the occluded artery. (B) After balloon expansion of the occluded segment, an Enterprise stent was deployed at the occluded segment. (C,D) After deployment of the stent with the micro-guidewire still in the artery, the proximal and distal markers of the stent were spread out with patency of the stent. (D) is the local enlargement of (C) between the proximal and distal markers of the stent. Arrows indicate the proximal and distal markers of the stent.
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F1
MRI, MR angiography (MRA), and CT angiography (CTA) revealed occlusion of the right vertebral artery at the V4 segment (Figure 1A), which was confirmed by diagnostic digital subtraction angiography (DSA). An angioplasty balloon catheter (Gateway, Boston Scientific, Natick, Massachusetts, USA) was advanced over the microwire, centered across the lesion, and inflated slowly for angioplasty (2.0 x 13 mm balloon) before an Enterprise stent (4.5 x 28 mm) was deployed at the occluded segment after accurate positioning (Figures 1B-D). At the time of stent deployment, the vertebral artery was straightened and smooth (Figure 1C), and the proximal end of the stent was wide open with the proximal markers of the stent being spread out (Figure 1D).
Collapse of the stent proximal end and management. (A,B) Withdrawal of the micro-guidewire and microcatheter led to collapse of the stent proximal end with the stent proximal markers in close contact, and the blood flow was reduced through the proximal end. The longer arrow indicates the proximal markers and the shorter arrow the distal markers. (C) A 300-cm micro-guidewire was navigated into the stent lumen through the proximal lateral stent mesh rather than through the proximal stent end. The longer arrow indicates the collapsed proximal markers of the stent, whereas the double arrows indicate the micro-guidewire through the stent lateral mesh. (D,E) After the micro-guidewire was sent to the distal segment of the basilar artery, the proximal stent end was opened with the proximal markers being spread out [(E), shorter arrow]. The longer arrow indicates the distal stent markers. (E) is the local enlargement of (D) between the proximal and distal markers of stent. (F) A second 200-cm micro-guidewire was sent right through the opened proximal stent end into the stent lumen (double arrows).
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F2
Once the micro-guidewire and the conveying microcatheter were withdrawn, the stent proximal end was collapsed because of compression of the wall of the curved artery, which was exhibited by the closed proximal markers in close contact (Figures 2A,B). Then, the 300-cm micro-guidewire was navigated to the stent proximal end and passed through the proximal lateral mesh of the stent (Figure 2C). Once the micro-guidewire was sent to the distal segment of the basilar artery, the vertebral artery was straightened, and the stent proximal end was opened with the proximal markers being spread out again (Figures 2D,E). Then, a second 200-cm Synchro micro-guidewire was navigated right through the stent proximal end into the real lumen of the stent and sent to the distal segment of basilar artery (Figures 2F, 3A,B).
Hand sketch to show the deployment of two micro-guidewires. (A) The first micro-guidewire (longer arrow) was sent through the lateral stent mesh into the stent lumen after collapse of the stent proximal end. (B) After the artery was straightened by the first micro-guidewire with the stent proximal end being opened, the second micro-guidewire (double short arrows) was sent right through the opened proximal end for deployment of a supporting stent.
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F3
Then, a second 200-cm Synchro micro-guidewire was navigated right through the stent proximal end into the real lumen of the stent and sent to the distal segment of basilar artery (Figures 2F, 3A,B).
Rescue management of the collapsed stent end. (A) An Apollo stent (2.5 x 10 mm) was navigated along the 200-cm micro-guidewire to the proximal end of the Enterprise stent and expanded for deployment (arrow). (B) The Apollo stent was deployed to partially overlap with the Enterprise stent (arrow). (C) The arrow indicates the deployed Apollo stent. (D) DynaCT scan demonstrated partial overlap of the distal Enterprise stent with the proximal Apollo stent. (E,F) After stenting, both stents were well-patent with favorable forward flow.
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Apollo 2.5 x 10 mm balloon-expanded stent (MicroPort Medical, Shanghai, China) was navigated along the Synchro micro-guidewire to overlap partially with the proximal segment of the Enterprise stent and was expanded with 4 atm pressure to support the proximal end of the first stent (Figures 4A-C). Angiography revealed good apposition of the two stents against the arterial wall with unobstructed blood flow through the stents and improved blood flow in the distal segment. Postoperative vertebral angiography showed complete recanalization of the occluded arterial segment (Figures 4B,C), and the Thrombolysis in Cerebral Infarction blood flow was grade 3. DynaCT scan revealed partially overlapped stents (Figure 4D). After stenting, both stents were well-patent with favorable forward flow (Figures 4E,F).
Follow-up angiography at 6 months after stenting demonstrates unobstructed blood flow through the stented vertebral artery (A,B) with no stenosis.
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DSA demonstrated patent stents and unobstructed blood flow through the stents (Figure 5).