The goal of stent retriever–based thrombectomy is removal of embolic clots in patients with intracranial large artery occlusion. However, outcomes of stent retrieval may differ between acute arterial occlusions due to intracranial atherosclerotic disease (IAD) and those due to embolism. This case series describes the outcomes of stent retriever–based thrombectomy and rescue treatments in 9 patients with IAD-related occlusion.
Among patients who underwent endovascular treatment for acute intracranial large artery occlusion, those in whom stent retrieval was attempted as first-line treatment were included in this review. IAD was defined as significant fixed focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment.
Median number of stent retriever passes was 2 (range, 1-3), and temporary bypass was seen in all patients. Immediate partial recanalization (arterial occlusive lesion grade 2-3) was observed in 7 patients. Immediate modified thrombolysis in cerebral infarction grade 2b-3 was seen in 6 patients, but the lesions often required rescue treatment due to reocclusion or flow insufficiency. In terms of rescue treatments, angioplasty and intra-arterial tirofiban infusion seemed to be effective.
Our findings suggest that stent retrieval can effectively remove thrombi from stenotic lesions and achieve partial recanalization despite the tendency toward reocclusion in most patients with IAD-related occlusion. Further research into the use of rescue treatments, such as tirofiban infusion and angioplasty, is warranted.
Intravenous recombinant tissue plasminogen activator (rtPA) infusion was the first approved treatment for acute ischemic stroke [
Recently, randomized controlled studies of endovascular treatments for acute ischemic stroke due to intracranial large artery occlusion have demonstrated improved efficacy [
There are few reports of emergent thrombectomy using stent retrievers in patients with acute ischemic stroke and IAD-related occlusion [
Patients who underwent endovascular treatment for acute ischemic stroke due to intracranial large artery occlusion at a Korean university hospital between July 2013 and May 2015 were screened. Only those who underwent endovascular treatment with the Solitaire flow restoration (FR) revascularization device (Covidien, Irvine, CA, USA) as the first-line method were included. IAD was defined as significant fixed focal stenosis at the occlusion site, which was evident on final angiographic assessment or observed during endovascular treatment. Significant stenosis was defined as (1) degree of fixed stenosis >70%, or (2) any degree of fixed stenosis with either flow and perfusion impairment on angiography or an evident tendency toward reocclusion even after sufficient treatment with stent retrieval. When angioplasty or stent insertion achieved full recanalization of intracranial stenosis, the case was classified as IAD. Patients whose final angiographic assessment showed complete recanalization with arterial occlusive lesion (AOL) grade 3 were excluded from this study because their stroke etiology was proved to involve embolism. Patients with an arterial occlusion etiology of moyamoya disease, dissection, or vasculitis also were excluded. Cases with vessel injury accompanied by an interventional procedure, and those in which the occlusion site was never recanalized because the underlying IAD could not be evaluated also were excluded from this study.
Patient outcome was analyzed according to the immediate effects of stent retrieval as the primary treatment method. Modified thrombolysis in cerebral infarction grade was used to evaluate reperfusion status [
Among 53 patients who underwent endovascular treatment with the Solitaire FR device as the first-line method, IAD-related occlusion was observed in 9 (8 men, 1 woman; median age, 63 years; range, 57-77 years) (
Median number of stent retriever passes was 2 (range, 1-3). Temporary bypass was seen in all patients when the stent retriever was deployed. Following thrombectomy, immediate reperfusion (modified thrombolysis in cerebral infarction grade 2b-3) was seen in 7 patients, and immediate partial recanalization (AOL grade 2-3) was seen in 6. On angiography, the thrombi were somewhat removed in all patients; however, most removed clots were very small or not visible in the stent.
Both patients with IAD-related occlusion affecting the BA trunk had very poor outcomes. In both cases, the stenotic lengths were >10 mm. In patient No. 4, the lesion was repeatedly reoccluded despite several stent retrieval trials and partial recanalization after angioplasty. Computed tomography (CT) angiography showed that the BA was reoccluded 5 hours later, and a second emergent procedure was performed. The patient’s consciousness level improved, but he still demonstrated locked-in syndrome 3 months after presentation. In patient No. 5, the lesion was repeatedly reoccluded during stent retrieval trials, so successive angioplasty was performed. Despite those efforts, blood flow remained stagnant at the stenotic site. Thus, a Wingspan stent (Stryker, Kalamazoo, MI, USA) was deployed, and poststenting angioplasty was performed. Although the patient’s recanalization and reperfusion grades improved, as did his consciousness level, he remained locked-in at 3 months.
In this study, we found that the effectiveness of stent retrievers for treating acute IAD-related occlusion was somewhat limited because of hidden stenosis. Despite this limited effectiveness,
The performance of stent retrievers for treating IAD-related occlusion, and even its frequency, has been rarely reported. In this study, we tried to describe the immediate effects of endovascular treatment in 9 patients. The proportion of IAD-related occlusion at our institution appears to be higher than that reported for non-Asian populations. Indeed, one Korean study showed that IAD-related occlusion accounted for 23% of acute ischemic stroke cases and endovascular treatment [
IAD-related occlusion may result from
Stent retrievers are also useful for planning rescue treatments (e.g., angioplasty or additional stenting) because IAD-related occlusions tend to reocclude. When a stent retriever is deployed and bypass flow is observed, interventionalists can measure the stenotic length and determine the curvature of the vessel. Different rescue treatments were not tested in the current study.
Angioplasty was effective in the distal MCA and intracranial vertebral arteries. Intracranial stenting, however, was not performed routinely due to concerns of hemorrhagic transformation, which cannot be treated with antithrombotics. In addition, angioplasty with or without stenting should be decided with caution when performed on a stenotic vessel near its branching small arteries. In one patient who had severe BA trunk occlusion, angioplasty was performed and a Wingspan stent was deployed following repeat stent retriever–based thrombectomy. The artery achieved complete recanalization and was patent on follow-up CT angiography. Unfortunately, although the patient’s level of consciousness recovered, he remained in a locked-in state due to a diffuse pontine lesion. If perforators exist near the stenotic lesion (e.g., anterior inferior cerebellar arteries in the BA trunk or striatocapsular arteries in the MCA trunk), angioplasty and intracranial stenting should be performed carefully, because ischemic complications have been reported to occur more often in the BA, according to a previous study regarding intracranial stenting for intracranial stenosis [
The effect of intra-arterial tirofiban infusion in this study is consistent with that reported in a previous study [
This study has some limitations. First, it was a retrospective study performed at one hospital. In addition to the rare disease entity, the small cohort requires caution when interpreting the results. Nevertheless, this is the first study to describe the performance of stent retriever–based thrombectomy for intracranial large artery occlusion due to IAD. Another limitation is the possibility of selection error. For example, we excluded patients whose vessels were never recanalized. Since IAD may be hidden in those cases, the recanalization power might have been overestimated. Consequently, we plan to perform a further prospective multicenter study.
IAD-related occlusion was observed in 17% of patients who underwent stent retriever–based thrombectomy. This method successfully removed
This research was partly supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2014R1A1A1008249).
The authors have no financial conflicts of interest.
A 56-year-old man (patient No. 3) presented with left hemispheric syndrome. Baseline magnetic resonance imaging (MRI) shows an acute left internal borderzone infarction on diffusion-weighted imaging, and a large perfusion defect on time-to-peak of perfusion-weighted imaging (A). Initial cerebral angiography shows occlusion of the distal M1 segment of the left middle cerebral artery (B). Temporary blood flow bypass is seen when the Solitaire FR stent is being deployed (C). Although some clots were removed at the occlusion site, occlusion is still seen at a more distal vessel (D). After 3 stent retrieval passes, partial recanalization was achieved, but flow still seems stagnated (E). After 2 angioplasties (F), complete reperfusion was fully achieved (G). Repeat MRI performed on the fifth day of admission shows similar infarct volume and complete recovery of the perfusion defect (H). The patient’s modified Rankin Scale score was 1 at 3 months and 0 at 1 year.
Baseline characteristics and immediate effects of stent retrieval
Case No. | Sex | Age (year) | Cardioembolic potential | NIHSS score on admission | Occlusion site on CTA | IV rtPA | No. of passes | Temporary bypass | Immediate mTICI grade | Immediate AOL grade | Thrombus removal |
---|---|---|---|---|---|---|---|---|---|---|---|
1 | M | 61 | None | 4 | VA | Yes | 2 | Yes | 0 | 0 | Yes |
2 | M | 73 | None | 18 | M1 of MCA | Yes | 1 | Yes | 3 | 2 | Yes |
3 | M | 56 | None | 9 | M1 of MCA | Yes | 3 | Yes | 3 | 2 | Yes |
4 | M | 57 | None | 30 | BA trunk | No | 3 | Yes | 2a | 1 | Yes |
5 | M | 57 | None | 28 | BA trunk | Yes | 2 | Yes | 3 | 2 | Yes |
6 | M | 63 | None | 18 | M1 of MCA | No | 2 | Yes | 2b | 2 | Yes |
7 | F | 83 | None | 17 | M1 of MCA | No | 1 | Yes | 3 | 2 | Yes |
8 | M | 81 | None | 16 | M1 of MCA | Yes | 1 | Yes | 3 | 1 | Yes |
9 | M | 68 | None | 9 | M1 of MCA | Yes | 2 | Yes | 3 | 2 | Yes |
New distal artery occlusion was seen after stent retrieval was attempted.
AOL, arterial occlusive lesion; BA, basilar artery; CTA, computed tomography angiography; IV, intravenous; MCA, middle cerebral artery; mTICI, modified thrombolysis in cerebral infarction; NIHSS, National Institutes of Health Stroke Scale; rtPA, recombinant tissue plasminogen activator; VA, vertebral artery.
Rescue treatments and procedure times
Case No. | Rescue therapy | Angioplasty | Stenting | Tirofiban | Onset to puncture (minute) | Puncture to 1st deployment (minute) | 1st deployment to recanalization (minute) |
---|---|---|---|---|---|---|---|
1 | Yes | Yes | - | - | 173 | 53 | 48 |
2 | Yes | Yes | - | - | 381 | 68 | 29 |
3 | Yes | Yes | - | - | 287 | 33 | 69 |
4 | Yes | Yes | - | - | 392 | 39 | 59 |
5 | Yes | Yes | Yes | - | 203 | 66 | 84 |
6 | No | - | - | - | 352 | 29 | 33 |
7 | Yes | - | - | Yes | 698 |
30 | 48 |
8 | Yes | - | - | Yes | 154 | 40 | 38 |
9 | No | - | - | - | 313 | 31 | 31 |
Patient had wake-up stroke; therefore, onset time was last normal time before sleep. Endovascular treatment was determined by institutional diffusion-perfusion mismatch criteria.
Procedural and clinical outcomes after endovascular treatment
Case No. | Final AOL grade | Final mTICI grade | ICH | SAH | Dissection | Stenotic degree on CTA within 10 days (%) | NIHSS score at discharge | mRS score at 3 months |
---|---|---|---|---|---|---|---|---|
1 | 2 | 2b | - | - | - | 40 | 0 | 0 |
2 | 2 | 2b | - | - | - | 20 | 16 | 5 |
3 | 2 | 3 | - | - | - | 80 | 3 | 1 |
4 | 2 | 2a | - | - | - | 100 | 30 | 5 |
5 | 2 | 2b | - | - | - | 0 | 28 | 5 |
6 | 2 | 2b | - | - | - | 70 | 10 | 4 |
7 | 2 | 3 | - | - | - | 90 | 1 | 1 |
8 | 2 | 3 | - | - | - | 90 | 8 | 1 |
9 | 2 | 3 | - | - | - | 100 |
6 | 1 |
Neurologic deterioration and reocclusion on repeat CTA were observed 5 hours after the emergent interventional procedure. The second immediate procedure including angioplasty was successful.
AOL, arterial occlusive lesion; CTA, computed tomography angiography; ICH, intracerebral hemorrhage; mRS, modified Rankin Scale; mTICI, modified thrombolysis in cerebral infarction; NIHSS, National Institutes of Health Stroke Scale; SAH, subarachnoid hemorrhage.