Use of the enterprise™ intracranial stent for revascularization of large vessel occlusions in acute stroke

Endovascular treatment of acute ischemic stroke

Endovascular treatment of acute ischemic stroke has become the first choice of treatment in large cerebral vessel occlusions, with a very high efficacy in terms of revascularization and reducing disability of affected patients. Revolutionizing acute therapy, it induced important paradigm shifts in the concepts of time and salvageable brain. In this review we focus on the current concepts of patient selection, imaging, techniques and perspectives of endovascular stroke treatment.

Intracranial Stenting after Failure of Thrombectomy with the emboTrap® Device

BACKGROUND

Approved alternatives in the guidelines for acute ischemic stroke patients who have failed intracranial thrombectomy are lacking. Primary permanent intracranial stenting was initially used in the era before thrombectomy and might still be a useful rescue treatment in acute stroke patients suffering from ongoing large vessel occlusion refractory to thrombectomy.

METHODS

The prospectively collected registry of patients with acute stroke caused by large vessel occlusions and treated with the emboTrap® device in Karolinska Hospital from October 2013 through March 2017 were retrospectively reviewed. Clinical outcome of non-recanalized patients with a thrombolysis in cerebral infarction (TICI) score of 0-1 after failed thrombectomy were compared with those who were treated with permanent intracranial stenting as rescue therapy. Favorable outcome was defined as modified Rankin scale 0-2.

RESULTS

The emboTrap® device was used in 201 patients. Persistent re-occlusions on withdrawal of the thrombectomy device were seen in 26 patients (13%) and of those, 12 individuals (46%) were treated with intracranial stenting. Baseline National Institutes of Health stroke scale (NIHSS), occlusion site, and onset-to-puncture time did not differ between the stenting group and the non-recanalized group. During the procedure half dose (5/12 patients) or full dose abciximab (6/12 patients), or aspirin (1/12 patient) was given intravenously immediately after stent placement. In 2 patients (17%) multiple stents were implanted. The stenting group had better functional outcomes at 3 months compared to the non-stenting group with 8/12 (66%) vs. 3/14 (21.4%, p < 0.05). Of the patients 5 (36%) in the non-stented group had died at 3 months follow-up, whereas mortality in the stenting cohort was 0% (p < 0.05) and no symptomatic intracranial hemorrhage (ICH) occurred in either group.

CONCLUSION

Intracranial stenting after failure of recanalization with thrombectomy led to a better rate of clinical outcome than leaving the patient non-recanalized. The required antiplatelet therapy, predominantly abciximab, did not lead to additional ICH.

Endovascular treatment in patients with carotid artery dissection and intracranial occlusion: a systematic review

Purpose

Recently, multiple randomised controlled trials showed efficacy of endovascular treatment over traditional care in patients with acute ischemic stroke due to an intracranial anterior circulation occlusion. Internal carotid artery (ICA) dissection with a concomitant intracranial occlusion is a rare but important cause of severe acute ischemic stroke. Although this subtype of acute ischemic stroke is mostly treated with endovascular treatment, treatment outcomes are still sparsely studied. This study assesses the clinical outcome and reperfusion rates by means of a systematic review.

Methods

Electronic databases of PubMed, EMBASE and Web of Science were searched up to October 1, 2016 for articles describing endovascular treatment in patients with intracranial artery occlusion and ICA dissection.

Results

Sixteen studies were included in the analysis. Most studies showed favourable outcome and successful reperfusion. However, most included studies had a high risk of bias.

Conclusion

In the reviewed studies, endovascular treatment in patients with ICA dissection and concomitant proximal intracranial occlusion was associated with favourable outcome. This could point in the direction of endovascular treatment being a beneficial treatment method for these patients. However, this review has only taken data of a limited group of patients into account. A pooled analysis of patients from recently published endovascular treatment trials and running registries is therefore recommended.

Electronic supplementary material

The online version of this article (doi:10.1007/s00234-017-1850-y) contains supplementary material, which is available to authorized users.

What is meant by "TICI"?

BACKGROUND

In 2003, Higashida et al proposed the Thrombolysis In Cerebral Infarction scale to evaluate angiographic intracranial flow. Our aim is to review how subsequently published studies define TICI.

MATERIALS AND METHODS

We used the ISI Web of Knowledge and SciVerse Scopus databases to search for "TICI" and "thrombolysis in cerebral infarction" and for articles that cited the original TICI paper from January 2004 through May 2012. Articles were categorized according to their definition of the TICI categories, typically grades 0-4, with grade 2 (partial reperfusion) subdivided into 2a and 2b, and rate of contrast entry to the perfused area. In addition, we catalogued the type of redefinitions of TICI subcategory 2 and additions of new categories.

RESULTS

Of 236 articles screened, 74 were included. Eight (11%) explicitly followed the TICI scale as originally defined. Thirty-seven (50%) cited Higashida but did not define their scale. Fifteen (21%) used and explained modified scales. Thirteen (18%) used the term TICI, but did not define the scale and did not cite Higashida. Eighteen (24%) specified a 2a subcategory. Nine defined grade 2a as <67% filling, 6 defined it as <50%, and 3 did not offer a percentage. Two studies added a 2c subcategory. Fifty-two (70%) used a cutoff level to define "successful reperfusion." Of these, 65% used TICI ≥2, 33% used TICI ≥2b, and 2% used TICI = 3.

CONCLUSIONS

There is substantial variability in the definition and/or application of the TICI scale in the literature. This variability could considerably impact our understanding of results of revascularization studies.

Intracranial thrombectomy using the Solitaire stent: a historical vignette

Introduction

The endovascular treatment of acute ischemic stroke has been revolutionized in the past years by the introduction of new devices for mechanical thrombectomy. Several tools were already available in 2008. The majority allowed the recanalization of acutely occluded intracranial arteries with acceptable levels of safety and efficacy, and with occasional failures.

Case presentation

On 3 March 2008, a 67-year-old woman was treated 3.5 h after the clinical onset of a right hemispheric stroke due to an embolic middle cerebral artery (MCA) M1 occlusion. The National Institutes of Health Stroke Scale (NIHSS) score prior to treatment was 10. Mechanical thrombectomy with a microbrush yielded a significant amount of thrombotic material without recanalization. Given the urgency of the situation, the uncertain outcome in the case of a persistent occlusion of the right M1 segment and the fact that no other device was available, a Solitaire stent was deployed within the occluded right M1 segment. After several minutes of incubation, the expanded stent was slowly withdrawn under continuous aspiration with instantaneous removal of the entire thrombus and complete recanalization of the right MCA with reperfusion of the whole MCA supply territory. Digital subtraction angiography showed neither peripheral emboli nor vasospasm. The patient made a complete clinical recovery with an NIHSS score of 0 at the 30 day follow-up.

Conclusion

The Solitaire stent was initially developed for the endovascular treatment of wide necked intracranial aneurysms but has been demonstrated to be safe and efficacious for intracranial thrombectomy. This was the first successful human clinical use of a Solitaire stent for this purpose and the ignition spark for the development of a whole generation of new devices, now called stent retrievers.

Stent placement for flow restoration in acute ischemic stroke: a single-center experience with the Solitaire stent system

BACKGROUND AND PURPOSE

In acute thromboembolic stroke, mechanical recanalization with stents may result in immediate flow restoration. The Solitaire stent can be used both for flow restoration and thrombectomy. In this single-center experience, we report safety and efficacy data on the application of the Solitaire stent.

MATERIALS AND METHODS

Between March 2009 and July 2010, 18 patients were treated with the Solitaire stent. To evaluate perfusion of the occluded vessel segment before and after the intervention, the TICI score was used (0-3). Clinical outcome was assessed by using the mRS at discharge.

RESULTS

Overall, recanalization was successful in 16 of 18 patients (88.8%). There were no procedure-related complications. Mean TICI score after the intervention was 2.3 ± 0.8. In 5 patients, reocclusion of the treated vessel occurred immediately after retrieval of the temporarily opened stent, and permanent stent deployment was performed to maintain stable perfusion. In 3 patients, hemorrhage occurred after successful recanalization. Five patients died (infarction, n = 3; hemorrhage, n = 1; organ failure, n = 1). A good clinical outcome (mRS ≤2) was achieved in 33.3% of the patients, 5.5% had a moderate outcome (mRS, 3/4), and 61.2% had a poor outcome or died (mRS, 5/6).

CONCLUSIONS

Application of the Solitaire stent in acute stroke results in a high recanalization rate (88.8%) without procedural complications and with a good outcome in one-third of patients. These results encourage further evaluation of the stent in larger patient populations.

Recanalization and reperfusion in acute ischemic stroke

Revascularization remains the most intuitive strategy to reverse ischemic injury associated with arterial occlusion in acute stroke. Revascularization may lead to opening of an occluded artery, or recanalization, yet restoration of downstream flow, or reperfusion, may not ensue. Revascularization strategies and novel devices continue to broaden options for the treatment of acute stroke, but it is increasingly apparent that selection criteria to identify ideal cases are needed to refine triage and minimize adverse events. The results of recent work on reperfusion may rapidly alter routine clinical practice for evolving ischemia in the brain.