Intracranial Carotid Occlusions : ADAPT versus SAVE and the role of Balloon Guide Catheters

PURPOSE

Specific decisions made by neurointerventionists are often lost behind the data of large-scale trials, and many of these studies have taken place before the development of new techniques and devices. This study compares the stent-retriever assisted vacuum-locked extraction (SAVE) technique with a direct aspiration first pass (ADAPT), as well as the use of a balloon guide catheter (BGC), in intracranial internal carotid artery (IC-ICA) occlusions.

METHODS

Observational and retrospective study from an Italian hospital, including patients who underwent thrombectomy for IC-ICA occlusion between 1 January 2019 and 31 March 2021.

RESULTS

Out of 91 IC-ICA occlusions, the ADAPT was the first choice in 20 (22%) and the SAVE in 71 (78%). A BGC was used in 32 (35%) cases, always in conjunction with the SAVE technique. The use of SAVE technique without BGC was associated with the least risk of distal embolization (DE) in the territory occluded (44% vs. 75% when ADAPT technique was used; p = 0.03) and achieved first pass effect (FPE) more frequently (51% vs. 25%, p = 0.09). When the SAVE technique was used, BGC (BGC-SAVE) compared to no BGC (NoBGC-SAVE) was associated with a tendency for less DE (31% vs. 44%, p = 0.3), more FPE (63% vs. 51%, p = 0.5), the same median number of passes (1, p = 0.8) and similar groin-to-recanalization times (36.5 vs. 35.5 min, p = 0.5), none of which reached statistical significance.

CONCLUSION

Our findings support the use of SAVE technique for IC-ICA occlusions; the added benefit of BGC compared to long sheaths was not remarkable in this sample.

Stentrievers : An engineering review

The advent of endovascular therapy for acute large vessel occlusion has revolutionized stroke treatment. Timely access to endovascular therapy, and the ability to restore intracranial flow in a safe, efficient, and efficacious manner has been critical to the success of the thrombectomy procedure. The stentriever has been a mainstay of endovascular stroke therapy, and current guidelines recommend the usage of stentrievers in the treatment of large vessel occlusion stroke. Despite the success of existing stentrievers, there continues to be significant development in the field, with newer stentrievers attempting to improve on each of the three key aspects of the thrombectomy procedure. Here, we elucidate the technical requirements that a stentriever must fulfill. We then review the basic variables of stent design, including the raw material and its form, fabrication method, geometric configuration, and further additions. Lastly, a selection of stentrievers from successive generations are reviewed using these engineering parameters, and clinical data is presented. Further avenues of stentriever development and testing are also presented.

Mechanical Thrombectomy of Acutely Occluded Flow Diverters

BACKGROUND

Embolization of intracranial aneurysms with the pipeline embolization device (PED; Medtronic, Dublin, Ireland) is a widely used technique. Despite adequate dual antiplatelet therapy and intraprocedural anticoagulation, in-stent thrombosis has been described. There is limited evidence for best management of this complication.

OBJECTIVE

To describe in detail the technique used to perform thrombectomy of a recently placed PED with in-stent thrombosis. The aim of the procedure is to leave the PED in place and only perform thrombectomy of the luminal clot.

METHODS

We describe two cases of successful thrombectomy with a stentriever of acutely occluded PEDs. A total of 2 patients underwent PED embolization of 2 previously clipped aneurysms. Despite optimal deployment of the PEDs and excellent angiographic results, both patients developed symptoms of right hemispheric stroke within 1 h of the procedure. A thrombectomy was performed in each patient with the stentriever within the newly deployed PED. Thrombectomy was successful and there was no evidence of PED displacement of vascular injury.

RESULTS

Stentriever thrombectomy of intraluminal clot can be performed effectively when the entire stentriever device is deployed within the PED. We did not experience any PED displacement, vessel damage, spasm, or device malfunction using this technique.

CONCLUSION

We report the use of a stentriever to perform thrombectomy for in-stent thrombosis after PED placement as an additional treatment option of acute occlusion. This technique has not been previously described.

More than five stentriever passes: real benefit or futile recanalization?

BACKGROUND AND AIMS

Clot extraction is associated with favorable outcome in patients with large vessel occlusions (LVO) undergoing endovascular thrombectomy (EVT). However, whether revascularization becomes futile or harmful with an increasing number of passes remains unknown.

METHODS

We performed a retrospective analysis of 271 consecutive patients with LVO who underwent stentriever-based EVT as the primary recanalization strategy. Primary outcomes including favorable recanalization, survival, and favorable functional outcomes were compared according to a dichotomized number of stentriever passes utilized with a cutoff of 4.

RESULTS

In the entire cohort, 234 (86%) patients reached favorable recanalization and 46 (17%) patients had ≥ 5 passes (range 5-40). Patients that had ≤ 4 passes had significantly higher rates of favorable recanalization and favorable outcomes and a trend towards lower mortality rates compared with those that had ≥ 5 stentriever passes (92% vs. 61%; p < 0.001, 52% vs. 30%; p = 0.009 and 12% vs. 22%, p = 0.098). Among patients that received ≥ 5 stentriever passes, 30% reached favorable outcomes. Patients who achieved recanalization after ≥ 5 passes had higher rates of favorable outcome in comparison with those who did not (p = 0.009). Among patients that had ≥ 5 stentriever passes favorable recanalization (OR 97.3, 95%CI 2.8-3399.3) and admission NIHSS (OR 0.77, 95%CI 0.60-0.99) remained independent predictors of favorable outcome, whereas the number of passes did not.

CONCLUSIONS

A substantial proportion of patients reach favorable outcomes even when ≥ 5 stentriever passes are performed. Treatment choices should be individualized based on personal preferences and expertise as well as on patient and clot-specific characteristics.

Number of stentriever passes and outcome after thrombectomy in stroke

BACKGROUND AND PURPOSES

Stroke secondary to emergent large vessel occlusions (ELVO) involving the anterior circulation can be treated with intravenous tissue plasminogen activator (IV-tPA) or thrombectomy. Data regarding the influence of the number of stentriever passes needed for vessel recanalization on outcome is lacking.

PATIENTS AND METHODS

We prospectively accrued data on consecutive patients with ELVO that were treated with thrombectomy. Procedural details including the number of stentriever passes needed to achieve vessel recanalization and clot length were collected. Functional outcome was determined with the modified Rankin Scale (mRS) at 90 days post stroke with mRS ≤ 2 considered favorable outcome. Data on demographics, risk factors, stroke severity, survival, and occurrence of symptomatic intracranial hemorrhage (sICH) was also collected.

RESULTS

On univariate analysis more than one pass needed to achieve recanalization impacted survival and functional outcome after 90 days as did age, stroke severity and collateral and reperfusion status. On multivariate logistic regression the number of passes needed to achieve revascularization (OR: 10.0, 95% CI: 2.28-43.94, P = 0.002), age (OR: 0.90, 95% CI: 0.84-0.96, P = 0.001) and collateral status (OR: 7.90, 95% CI: 1.87-33.35, P = 0.005) remained significant modifiers for favorable outcome. On logistic regression the only variable associated with the need to perform more than a single stentriever pass was time from symptom onset to target vessel recanalization (OR: 1.007, 95% CI: 1.002-1.012).

CONCLUSIONS

The number of passes needed to achieve target vessel recanalization modifies outcome after thrombectomy and successful recanalization after a single pass is associated with favorable outcome.

Endovascular Retrieval of Dislodged Neurovascular Devices with a Stentriever: Case Series and Technical Review

PURPOSE

Endovascular treatment of neurovascular disorders is now well established as effective and safe; however, the nature of the intracranial vasculature poses unique challenges. The unintentional dislodgement or fracture of a device and its migration within cerebral vessels is a complication with serious potential morbidity that must be managed urgently. In this series, the authors describe 7 cases of a stentriever being used to remove foreign objects from within the cerebral vasculature.

METHODS

A retrospective search of all interventional neurovascular procedures performed in 2017 at a tertiary metropolitan hospital was performed to identify cases of dislodged devices.

RESULTS

Five dislodged endovascular coils, 1 microcatheter, and 1 fractured stentriever were technically successfully retrieved. In 6 of the cases, the foreign object was successfully removed with a stentriever alone, whereas 1 case used a J-tip wire and a "J-tip flick" to manipulate the coil and facilitate retrieval. Stentrievers, particularly when used alone, confer the advantages of speed, cost, as well as being tailor-made for cerebral vessels. They also allow continuous blood flow when deployed, a critical advantage when considering cerebral perfusion. Critical techniques include the gradual deployment of the stentriever alongside the foreign object to allow its entanglement and partial resheathing, so that the foreign object can become pinned within the microcatheter. Stentrievers do remain limited by vessel caliber and are less able to entangle larger, stiffer devices.

CONCLUSION

The migration of foreign devices during neurointerventional procedures is a serious complication requiring urgent treatment. This case series highlights the efficacy and advantages of using a stentriever and suggests its consideration as a first-line technique in recovering dislodged foreign bodies in the cerebral vasculature.

Stent-Retriever Angioplasty for Recurrent Post-Subarachnoid Hemorrhagic Vasospasm - A Single Center Experience with Long-Term Follow-Up

PURPOSE

We report our experience of using stent-retrievers for recurrent cerebral vasospasm (CVS) secondary to aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

We performed a retrospective review of our prospectively maintained institutional database to identify all patients with recurrent CVS and treated with stent-retrievers between April 2011 and May 2017. All patients were initially treated with intra-arterial (IA) vasodilators and were subsequently re-treated with stent-retrievers if they developed recurrent vasospasm. Patients were categorized into two groups, those in which IA vasodilators were given again prior to the stent-retriever deployment (VD-first) and those in which the stent-retriever was deployed first and IA vasodilators were given subsequently (SR-first).

RESULTS

We identified 12 patients (7 females, mean age 54.9 years), 5 in the VD-first and 7 in the SR-first cohorts. Stent-retriever lumen dilatation was attempted in 53 segments (VD-first 14, SR-first 39). Stent-retriever deployment was technically feasible in all cases. Vasodilation occurred in 71.4% (10/14 segments) in the VD-first group and 82.1% (32/39 segments) in SR-first group. Additional treatment was required in 5 segments. There was no recurrent vasospasm in the SR-first group; however, 3 patients (60%) in the VD-first group showed recurrent vasospasm. No angiographical abnormality was found at long-term follow-up (7 patients, mean 29.1 months).

CONCLUSION

The use of stent-retrievers to treat cerebral vasospasm is technically feasible and can cause long-term vasodilatation; however, this effect is maximized if stent-retrievers are used prior to infusion of IA vasodilators.

Direct Thrombectomy versus Bridging for Patients with Emergent Large-Vessel Occlusions

Background and Aims

Patients with emergent large-vessel occlusion (ELVO) that present earlier than 4 h from onset are usually treated with bridging systemic thrombolysis followed by endovascular thrombectomy (EVT). Whether direct EVT (dEVT) could improve the chances of favorable outcome remains unknown.

Methods

Consecutively, prospectively enrolled patients with ELVO presenting within 4 h of onset were entered into a National Acute Stroke Registry of patients undergoing revascularization. Patients treated with bridging were compared to those treated with dEVT. Excellent outcome was defined as having a modified Rankin Scale score ≤1 at 90 days following stroke.

Results

Out of 392 patients that underwent thrombectomy, 270 (68%) presented within 4 h and were included. Of those, 159 (59%) underwent bridging and 111 (41%) underwent dEVT. Atrial fibrillation and congestive heart failure were more common in the dEVT group (43 vs. 30%, p = 0.04 and 20 vs. 8%, p = 0.009, respectively), but other risk factors, demographics, stroke severity and subtypes as well as baseline vessel patency state and time metrics did not differ. Excellent target vessel recanalization defined as TICI 3 (thrombolysis in cerebral infarction score) was more common in the dEVT group (75 vs. 61%, p = 0.03), but in-hospital mortality, discharge destinations, short- and long-term excellent outcome rates did not differ. On multivariate regression analysis, treatment modality did not significantly modify the chances of excellent outcome at discharge (OR 0.7; 95% CI 0.3-1.5) or at 3 months (OR 0.78 95% CI 0.4-1.4).

Conclusions

The chances of attaining excellent functional outcomes are similar in ELVO patients undergoing dEVT or bridging.

Endovascular Retrieval of Migrated Coil within the Distal Middle Cerebral Artery Using Stentriever Device

BACKGROUND

Displacement of endovascular coils during endovascular embolization of an intracranial aneurysm is a potentially life-threatening complication. Several methods for coil retrieval have been described, including the use of microsnares and microforceps retrieval devices. With the recent surge of stentriever implementation in the treatment of ischemic stroke, some operators are now using such devices in the retrieval of migrated coils. We present a case of a balloon-assisted coil embolization of a communicating segment internal carotid artery aneurysm, complicated by coil migration far distally into the middle cerebral artery, which was retrieved successfully with a stentriever. To the best of our knowledge, this is the furthest migration of a coil to be successfully retrieved with a stentriever. We review conservative and invasive management of displaced coils and the technical advantages of stentrievers over retrieval devices.

METHODS

The patient's medical records were retrospectively reviewed, including clinical and radiographic information. This study received institutional review board approval.

RESULTS

The patient was treated with balloon-assisted coil embolization of the internal carotid artery aneurysm. The migrated coil was retrieved successfully using a novel application of a stentriever.

CONCLUSIONS

In certain situations, a stentriever does not mandate complete ensnaring of the target to be retrieved and thus need not always be deployed distal to a migrated coil mass to be successful. Due to the mechanical advantage of strut-engagement, stentrievers can afford to be positioned in relatively suboptimal positions, and this is especially useful in cases involving tortuous and small distal vessels (<2 mm diameter).

Dwell Time of Stentriever Influences Complete Revascularization and First-Pass TICI 3 Revascularization in Acute Large Vessel Occlusive Stroke

OBJECTIVE

In acute ischemic stroke with large vessel occlusion, the interaction between the clot retriever and the stent is critical for achieving successful recanalization. The ideal time of stent deployment (dwell time [DT]) to improve revascularization is currently unknown. We systematically analyzed the effect of different DT on final angiographic and clinical outcomes of patients who underwent mechanical thrombectomy.

METHODS

The DT was progressively increased from 3 minutes to 5 minutes and then 8 minutes during the study period. The effect of DT on recanalization attempts, successful angiographic outcome (thrombolysis in cerebral ischemia [TICI] 2b or TICI 3), total revascularization time, and immediate and 3-month clinical outcomes were evaluated. The DT of 3 minutes and 5 minutes (DT3-5) was compared against DT of 8 minutes (DT8).

RESULTS

Forty patients were included in the analysis. Good angiographic outcome was observed in 94.1% of patients in the DT8 cohort with an average attempt of 1.2 compared with 78.3% with average attempts of 2.0 in other group. Single-pass good recanalization (TICI 2b or 3) and single-pass complete revascularization (TICI3) was significantly higher in the DT group compared with the DT3-5 group (82.4% vs. 43.5% [P = 0.013] and 42.9% vs. 8.7% [P = 0.003], respectively). A favorable trend toward a reduced overall procedural time (34.59 vs. 55.59 minutes) was observed, but was not statistically significant (P = 0.15).

CONCLUSIONS

Mild prolongation of DT to 8 minutes improves revascularization outcome with fewer attempts, possibly because of better clot-stent interaction.

Stroke: Basic and Clinical

Tissue plasminogen activator (tPA) was first approved in the USA 25 years ago for those who had experienced a recent occlusion (<3 h) of a cerebral vessel. Now, advances in clot retrieval (stentriever), in concert with tPA, heralds new optimism for ischemic stroke victims, but adds more pressure to identify therapies that will minimize hypoxic damage, protect compromised cells, and promote rehabilitation. In the past preclinical investigations have been poor at predicting potential clinical therapy, but they have contributed enormously to understanding post-stroke pathology. Current clinical trials ( www.strokecenter.org/trials ) anticipate a broad range of approaches: from hypothermia, to cell therapy, to neuroprotection.

Evolution of Endovascular Therapy in Acute Stroke: Implications of Device Development

Intravenous thrombolysis is an effective treatment for acute ischaemic stroke. However, vascular recanalization rates remain poor especially in the setting of large artery occlusion. On the other hand, endovascular intra-arterial therapy addresses this issue with superior recanalization rates compared with intravenous thrombolysis. Although previous randomized controlled studies of intra-arterial therapy failed to demonstrate superiority, the failings may be attributed to a combination of inferior intra-arterial devices and suboptimal selection criteria. The recent results of several randomized controlled trials have demonstrated significantly improved outcomes, underpinning the advantage of newer intra-arterial devices and superior recanalization rates, leading to renewed interest in establishing intra-arterial therapy as the gold standard for acute ischaemic stroke. The aim of this review is to outline the history and development of different intra-arterial devices and future directions in research.