Special Endovascular Treatment for Acute Large Artery Occlusion Resulting From Atherosclerotic Disease

Basilar artery stenting in hyperacute stroke: A systematic review of published cases

BACKGROUND AND PURPOSE

Basilar artery stenting is a rescue therapy in the management of hyperacute stroke. Published data on efficacy and safety are limited.

METHODS

A systematic review of published studies was performed in accordance with PRISMA guidelines. Inclusion criteria were adult patients with ischemic stroke with permanent basilar artery stent placement within 48 h of onset. Data were extracted by two independent reviewers. Additional cases from our institution were identified via a local stroke registry.

RESULTS

Of 212 screened articles, patient-level data was reported in 35 studies (87 individuals) and six additional patients were included from our registry. Patients (n = 93, 63 % male; median age 64) most often presented with mid-basilar occlusion (52 %) and 76 % received treatment within 12 hours of onset. Favorable angiographic results occurred in 67 %. The final modified Rankin Scale score (mRS) was 0-3 for 56 % of patients; mortality was 29 %. Those with complete flow post-procedure were more likely to have a final mRS of 0-3 (p = 0.05).

CONCLUSIONS

In 93 cases of basilar stenting in hyperacute stroke, favourable angiographic and functional outcomes were reported in 67 % and 56 % of patients, respectively. International multicenter registries are required to establish benefit and identify patient and technical factors that predict favorable outcomes.

"The microcatheter contrast injection technique": A novel technique to detect the proximal end of a thrombus in mechanical thrombectomy

Background: An aspiration catheter needs to attach to a thrombus in order to achieve first-pass recanalization by mechanical thrombectomy (MT) for acute ischemic stroke (AIS), particularly that using a direct aspiration first pass technique. The meniscus sign, which is defined as meniscoid contrast opacification indicating the proximal edge of a thrombus, has been suggested to contribute to successful recanalization. In some cases, the meniscus sign is not detected following an injection of contrast medium through a guiding catheter. To precisely identify the location of a thrombus, we use "the microcatheter contrast injection (MCI) technique," which accurately shows the proximal edge of a thrombus. We herein introduce this novel technique and discuss its efficacy in MT. Methods: In cases without the meniscus sign, a microcatheter was advanced to the distal end of contrast opacification, and contrast medium was injected through the microcatheter to detect the meniscus sign. An aspiration catheter was then advanced to the thrombus indicated by the meniscus sign and slowly withdrawn under aspiration. Results: 29 patients underwent MT for AIS using the MCI technique. Even in cases without the meniscus sign on initial angiography, the MCI technique accurately revealed the proximal edge of the thrombus. Moreover, middle cerebral artery occlusion due to atherosclerotic stenosis and displacement of the aspiration catheter and thrombus axis were detected using this technique. Conclusions: The MCI technique may effectively reveal the exact site of a thrombus and increase the success rate of first-pass recanalization.

Rescue therapy after thrombectomy for large vessel occlusion due to underlying atherosclerosis: review of literature

In this review article, we summarized the current advances in rescue management for reperfusion therapy of acute ischemic stroke from large vessel occlusion due to underlying intracranial atherosclerotic stenosis (ICAS). It is estimated that 24-47% of patients with acute vertebrobasilar artery occlusion have underlying ICAS and superimposed in situ thrombosis. These patients have been found to have longer procedure times, lower recanalization rates, higher rates of reocclusion and lower rates of favorable outcomes than patients with embolic occlusion. Here, we discuss the most recent literature regarding the use of glycoprotein IIb/IIIa inhibitors, angioplasty alone, or angioplasty with stenting for rescue therapy in the setting of failed recanalization or instant/imminent reocclusion during thrombectomy. We also present a case of rescue therapy post intravenous tPA and thrombectomy with intra-arterial tirofiban and balloon angioplasty followed by oral dual antiplatelet therapy in a patient with dominant vertebral artery occlusion due to ICAS. Based on the available literature data, we conclude that glycoprotein IIb/IIIa is a reasonably safe and effective rescue therapy for patients who have had a failed thrombectomy or have residual severe intracranial stenosis. Balloon angioplasty and/or stenting may be helpful as a rescue treatment for patients who have had a failed thrombectomy or are at risk of reocclusion. The effectiveness of immediate stenting for residual stenosis after successful thrombectomy is still uncertain. Rescue therapy does not appear to increase the risk of sICH. Randomized controlled trials are warranted to prove the efficacy of rescue therapy.

Imaging of Central Nervous System Ischemia

OBJECTIVE

This article describes imaging modalities used in the evaluation of patients presenting with symptoms of acute ischemic stroke.

LATEST DEVELOPMENTS

The year 2015 marked the beginning of a new era in acute stroke care with the widespread adoption of mechanical thrombectomy. Subsequent randomized controlled trials in 2017 and 2018 brought the stroke community even further into this new territory with the expansion of the eligibility window for thrombectomy using imaging-based patient selection, which led to an increase in the use of perfusion imaging. Now, after several years of routine use, the debate is ongoing as to when this additional imaging is truly required and when it results in unnecessary delays in time-sensitive stroke care. At this time, more than ever, a robust understanding of neuroimaging techniques, applications, and interpretation is essential for the practicing neurologist.

ESSENTIAL POINTS

CT-based imaging is the first step in most centers for the evaluation of patients presenting with symptoms of acute stroke because of its wide availability, speed, and safety. Noncontrast head CT alone is sufficient for IV thrombolysis decision making. CT angiography is very sensitive for the detection of large-vessel occlusion and can be used reliably to make this determination. Advanced imaging including multiphase CT angiography, CT perfusion, MRI, and MR perfusion can provide additional information useful for therapeutic decision making in specific clinical scenarios. In all cases, it is essential that neuroimaging be performed and interpreted rapidly to allow for timely reperfusion therapy.

The relationship between vertebrobasilar artery calcification and intracranial atherosclerosis-related occlusion in thrombectomy

Background and purpose

Distinguishing between intracranial atherosclerosis-related occlusion (ICAS-O) and non-ICAS-O can benefit strategies of identifying the need for surgical plans prior to thrombectomy. We investigated the association between vertebrobasilar artery calcification (VBAC) and ICAS-O in acute ischemic stroke patients undergoing thrombectomy.

Methods

Patients were recruited from a prospective single-center registration study who had undergone thrombectomy between October 2017 and October 2021. The enrolled patients were divided into ICAS-O and non-ICAS-O, as determined by the intraarterial therapy process. The occurrences of VBAC were recorded on intracranial non-contrast computed tomography (NCCT) scans before thrombectomy. The association between VBAC and ICAS-O was assessed using binary logistic regression.

Results

A total of 2732 patients who had undergone digital subtraction angiography were reviewed, and 314 thrombectomy patients (mean age: 65.4 years, 36.6% female) with NCCT were enrolled in this study. VBAC was detected before thrombectomy in 113 (36%) out of 314 patients. Age, hypertension, and diabetes were associated with VBAC, and a higher frequency of VBAC was identified in patients presenting posterior circulation. ICAS-O accounts for 43% (135/314) in eligible patients. From multivariable analyses, VBAC was identified as an independent predictor of ICAS-O (adjusted odds ratio, 6.16 [95% CI, 2.673–14.217], P < 0.001). Meanwhile, the (VBAC[+] atrial fibrillation[-]) group displayed higher rates of ICAS-O than the (VBAC[-] atrial fibrillation [-]) group (P < 0.001).

Conclusions

We demonstrated that VBAC is an independent risk factor for ICAS-O in patients who underwent thrombectomy. Patients free of atrial fibrillation with VBAC have more trend to be ICAS-O.

Effect of Intravenous Tirofiban vs Placebo Before Endovascular Thrombectomy on Functional Outcomes in Large Vessel Occlusion Stroke: The RESCUE BT Randomized Clinical Trial

IMPORTANCE

Tirofiban is a highly selective nonpeptide antagonist of glycoprotein IIb/IIIa receptor, which reversibly inhibits platelet aggregation. It remains uncertain whether intravenous tirofiban is effective to improve functional outcomes for patients with large vessel occlusion ischemic stroke undergoing endovascular thrombectomy.

OBJECTIVE

To assess the efficacy and adverse events of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke secondary to large vessel occlusion.

DESIGN, SETTING, AND PARTICIPANTS

This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 55 hospitals in China, enrolling 948 patients with stroke and proximal intracranial large vessel occlusion presenting within 24 hours of time last known well. Recruitment took place between October 10, 2018, and October 31, 2021, with final follow-up on January 15, 2022.

INTERVENTIONS

Participants received intravenous tirofiban (n = 463) or placebo (n = 485) prior to endovascular thrombectomy.

MAIN OUTCOMES AND MEASURES

The primary outcome was disability level at 90 days as measured by overall distribution of the modified Rankin Scale scores from 0 (no symptoms) to 6 (death). The primary safety outcome was the incidence of symptomatic intracranial hemorrhage within 48 hours.

RESULTS

Among 948 patients randomized (mean age, 67 years; 391 [41.2%] women), 948 (100%) completed the trial. The median (IQR) 90-day modified Rankin Scale score in the tirofiban group vs placebo group was 3 (1-4) vs 3 (1-4). The adjusted common odds ratio for a lower level of disability with tirofiban vs placebo was 1.08 (95% CI, 0.86-1.36). Incidence of symptomatic intracranial hemorrhage was 9.7% in the tirofiban group vs 6.4% in the placebo group (difference, 3.3% [95% CI, -0.2% to 6.8%]).

CONCLUSIONS AND RELEVANCE

Among patients with large vessel occlusion acute ischemic stroke undergoing endovascular thrombectomy, treatment with intravenous tirofiban, compared with placebo, before endovascular therapy resulted in no significant difference in disability severity at 90 days. The findings do not support use of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR-IOR-17014167.

Endovascular Treatment of ICAS Patients: Targeting Reperfusion Rather than Residual Stenosis

Background and Purpose: Previous studies showed that acute reocclusion after endovascular therapy is related to residual stenosis. However, we observed that reperfusion status but not residual stenosis severity is related to acute reocclusion. This study aimed to assess which factor mention above is more likely to be associated with artery reocclusion after endovascular treatment. Methods: This study included 86 acute ischemic stroke patients who had middle cerebral artery (MCA) atherosclerotic occlusions and received endovascular treatment within 24 h of a stroke. The primary outcomes included intraprocedural reocclusion assessed during endovascular treatment and delayed reocclusion assessed through follow-up angiography. Results: Of the 86 patients, the intraprocedural reocclusion rate was 7.0% (6/86) and the delayed reocclusion rate was 2.3% (2/86). Regarding intraprocedural occlusion, for patients with severe residual stenosis, patients with successful thrombectomy reperfusion showed a significantly lower rate than unsuccessful thrombectomy reperfusion (0/30 vs. 6/31, p = 0.003); on the other hand, for patients with successful thrombectomy reperfusion, patients with severe residual stenosis showed no difference from those with mild to moderate residual stenosis in terms of intraprocedural occlusion (0/30 vs. 0/25, p = 1.00). In addition, after endovascular treatment, all patients achieved successful reperfusion. There was no significant difference in the delayed reocclusion rate between patients with severe residual stenosis and those with mild to moderate residual stenosis (2/25 vs. 0/61, p = 0.085). Conclusion: Reperfusion status rather than residual stenosis severity is associated with artery reocclusion after endovascular treatment. Once successful reperfusion was achieved, the reocclusion occurrence was fairly low in MCA atherosclerosis stroke patients, even with severe residual stenosis.

Combination of Rescue Stenting and Antiplatelet Infusion Improved Outcomes for Acute Intracranial Atherosclerosis-Related Large-Vessel Occlusion

Background and Purpose: Intracranial atherosclerosis-related large-vessel occlusion caused by in situ thrombo-occlusion (ICAS-LVO) has been regarded an important reason for refractoriness to mechanical thrombectomy (MT). To achieve better outcomes for ICAS-LVO, different endovascular strategies should be explored. We aimed to investigate an optimal endovascular strategy for ICAS-LVO.

Methods: We retrospectively reviewed three prospective registries of acute stroke underwent endovascular treatment. Among them, patients with ICAS-LVO were assigned to four groups based on their endovascular strategy: (1) MT alone, (2) rescue intracranial stenting after MT failure (MT-RS), (3) glycoprotein IIb/IIIa inhibitor infusion after MT failure (MT-GPI), and (4) a combination of MT-RS and MT-GPI (MT-RS+GPI). Baseline characteristics and outcomes were compared among the groups. To evaluate whether the endovascular strategy resulted in favorable outcome, multivariable analysis was also performed.

Results: A total of 184 patients with ICAS-LVO were included. Twenty-four patients (13.0%) were treated with MT alone, 25 (13.6%) with MT-RS, 84 (45.7%) with MT-GPI, and 51 (27.7%) with MT-RS+GPI. The MT-RS+GPI group showed the highest recanalization efficiency (98.0%). Frequency of patent arteries on follow-up (98.0%, p < 0.001) and favorable outcome (84.3%, p < 0.001) were higher in the MT-RS+GPI group than other groups. The MT-RS+GPI strategy remained an independent factor for favorable outcome (odds ratio, 20.4; 95% confidence interval, 1.97–211.4; p = 0.012).

Conclusion: Endovascular strategy was significantly associated with procedural and clinical outcomes in acute stroke by ICAS-LVO. A combination of RS and GPI infusion might be an optimal rescue modality when frontline MT fails.

Angiographic And Clinical Response Of Intracranial Atherosclerotic Disease Large Vessel Occlusion Stroke Undergoing Mechanical Thrombectomy

OBJECTIVES

To identify whether intracranial atherosclerotic disease large vessel occlusion strokes differ compared to embolic large vessel occlusion strokes in angiographic response to mechanical thrombectomy and clinical course.

METHODS

Retrospective analysis of acute ischemic stroke patients with large vessel occlusion, due to intracranial atherosclerotic disease or embolic etiology, who underwent mechanical thrombectomy in a primary stroke center from 11/2015 to 4/2018. We categorized patients into intracranial atherosclerotic disease or embolic large vessel occlusion based on the procedural findings. We compared pretreatment, procedural variables, and post-procedural outcomes.

RESULTS

Ninety-five patients were included, 13 with intracranial atherosclerotic disease large vessel occlusion strokes and 82 with embolic large vessel occlusion strokes. Between the two groups, there was no statistically significant difference in angiographic success (100% for intracranial atherosclerotic disease and 89% for embolic large vessel occlusion strokes); first pass success (38% for intracranial atherosclerotic disease and 34% for embolic large vessel occlusion strokes); puncture-to-first-pass time; puncture-to-recanalization time (68 minutes for intracranial atherosclerotic disease and 62 minutes for embolic large vessel occlusion strokes); number of passes; or clinical outcomes. Intracranial angioplasty was performed in 6 (46%) of intracranial atherosclerotic disease large vessel occlusion patients, and in 5 (6%) of embolic large vessel occlusion patients (p < 0.0001).

CONCLUSIONS

Similar angiographic success and procedural time metrics are achievable with intracranial atherosclerotic disease large vessel occlusion and embolic large vessel occlusion therapy. This occurred with more frequent intracranial angioplasty for intracranial atherosclerotic disease large vessel occlusion strokes.

Endovascular Treatment of Acute Ischemic Stroke Due to Intracranial Atherosclerotic Large Vessel Occlusion : A Systematic Review

OBJECTIVE

To evaluate the efficacy and safety of endovascular treatment (ET) of acute ischemic stroke (AIS) caused by intracranial atherosclerotic large vessel occlusion (ICAS-LVO).

METHODS

A systemic review and meta-analysis were conducted on studies published between July 2005 and October 2018 on the outcomes of ET in patients with AIS due to ICAS-LVO. The outcomes of the ICAS-LVO and embolic LVO groups were also compared.

RESULTS

A total of 17 studies including 1315 subjects with ICAS-LVO were included. In the single-arm meta-analysis, the pooled estimates of successful recanalization rate, favorable outcomes, symptomatic intracranial hemorrhage and mortality were 88% (95% CI (95% confidence interval), 84-92%), 52% (95% CI, 47-56%), 5% (95% CI, 3-7%) and 15% (95% CI, 12-19%) respectively. The preferred primary treatment was stent-retriever thrombectomy (84.1%) and the preferred rescue treatment was stent implantation with or without percutaneous transluminal angioplasty (PTA, 32.7%). In the double-arm meta-analysis, the incidence of symptomatic intracranial hemorrhage was lower in the ICAS-LVO compared to the embolic-LVO group (OR (odds ratio) = 0.60, 95% CI, 0.46-0.77, p < 0.01), whereas the implementation of rescue treatment (OR = 5.94, 95% CI, 3.15-11.19, p < 0.01) and stenting rate (OR = 10.06, 95%CI, 4.43-22.85, p < 0.01) were higher in the ICAS-LVO group. Other parameters were similar in both groups.

CONCLUSION

The use of ET is a safe and effective therapeutic option for AIS due to ICAS-LVO. Stent-retriever thrombectomy and stent-implement are the preferred primary and rescue therapies respectively for ICAS-LVO. Less symptomatic intracranial hemorrhage and higher stenting were observed in the ICAS-LVO compared to the embolic-LVO group.

Angiographical Identification of Intracranial, Atherosclerosis-Related, Large Vessel Occlusion in Endovascular Treatment

Identification of intracranial, atherosclerosis-related, large vessel occlusion (ICAS-LVO) is important to set up an optimal endovascular treatment strategy, as most ICAS-LVOs require specific endovascular modalities for efficient recanalization. However, there is currently no decisive way to identify ICAS-LVO for endovascular treatment. Instead of the few, non-specific, clinical and imaging findings that operators have depended on, this review focused on the occlusion type, one of angiographical methods to identify the ICAS-LVO. Occlusion type was originally devised for predicting procedural details and endovascular outcomes of ICAS-LVO. Among occlusion types, truncal-type occlusion is regarded as a surrogate marker for ICAS-LVO. Although rare, false positives or negatives in truncal-type occlusion are possible. Nonetheless, occlusion type was easy to apply and reliably predictive of procedural outcomes. Furthermore, occlusion type can be determined prior to the procedure, which could allow it to be more helpful in setting up an optimal strategy before starting endovascular treatment.

Stent Expansion and In-Stent Thrombus Sign in the Trevo Stent Retriever Predict Recanalization and Possible Etiology During Mechanical Thrombectomy: A Case Series of 50 Patients with Acute Middle Cerebral Artery Occlusion

BACKGROUND

Interaction between the stent retriever and clot is a key factor for recanalization during mechanical thrombectomy. The aim of this study was to evaluate the association between radiographically apparent features during thrombectomy and angiographic outcomes using the Trevo stent retriever with a fully radiopaque strut.

METHODS

We retrospectively reviewed 50 patients with acute middle cerebral artery occlusion who were treated with the Trevo. Patients were divided into groups that achieved (first-pass recanalization group, n = 21) or did not achieve (non-first-pass recanalization group, n = 29) a modified Thrombolysis in Cerebral Ischemia score of 2b or 3 with the first-pass procedure. Patients were also divided into a thromboembolic (n = 39) and atherosclerotic (n = 11) group by occlusion etiology. We evaluated radiographic findings of the Trevo's strut (e.g., degree of stent expansion and filling defect of the thrombus in the strut [in-stent thrombus sign]) during the first-pass procedure.

RESULTS

Median stent expansion was significantly greater in the first-pass recanalization group than in the non-first-pass recanalization group (60% vs. 34%; P < 0.01) and in the thromboembolic group than in the atherosclerotic group (45% vs. 31%; P < 0.01). The receiver operator characteristic curve showed moderate capacity for prediction of recanalization and etiology, with an area under the curve of 0.83 and 0.73, respectively. In-stent thrombus sign was significantly more common in the thromboembolic group than in the atherosclerotic group (86% vs. 10%; P < 0.01).

CONCLUSIONS

Greater stent expansion was associated with recanalization after thrombectomy. The in-stent thrombus sign may be useful for etiology prediction. These radiographic findings could provide useful real-time feedback during procedures, reflecting clot-stent interaction.

Another Endovascular Therapy Strategy for Acute Tandem Occlusion: Protect-Expand-Aspiration-Revascularization-Stent (PEARS) Technique

OBJECTIVE

Initial stenotic occlusion of the internal carotid artery with intracranial artery occlusion in acute ischemic stroke is associated with high morbidity and can benefit from endovascular therapy. However, the optimal endovascular strategy is unclear. This study aimed to evaluate the feasibility of the "half" anterograde approach and clinical outcome of treated patients. Revascularization validity of the 2 "half" anterograde approach with (Protect-Expand-Aspiration-Revascularization-Stent [PEARS] technique) or without (plain technique) using an embolic prevention device and aspiration was also compared.

METHODS

Data on initial stenotic occlusion of the internal carotid artery with intracranial artery occlusion in our prospective stroke registry database between January 2015 and February 2017 were collected. Clinical and angiographic data were retrospectively analyzed. Clinical outcome was evaluated at 3 months, defined as a modified Rankin scale ≤2 as a good clinical outcome.

RESULTS

Overall, 26 patients with tandem occlusion were included; 96.3% of patients had successful recanalization. The rate of a good clinical outcome was 61.8%, symptomatic parenchymal hemorrhage was 7.7%, and mortality was 15.4%. The PEARS technique took less time (56 ± 14 vs. 97 ± 31 minutes; P = 0.002) and had less embolic events (0 vs. 30.8%; P = 0.012) compared with the plain technique. Use of the PEARS technique was an independent predictor for shortening revascularization time (β = -0.651, P = 0.001).

CONCLUSIONS

The half anterograde approach technique is feasible and safe for treating tandem occlusion. Furthermore, the PEARS technique is associated with a shorter reperfusion time and less embolic events than the plain technique, and should be recommended in tandem occlusion.