Background: Flow-diverting stents (FDS) have revolutionized the endovascular management of unruptured, complex, wide-necked, and giant aneurysms. There is no consensus on management of complications associated with the placement of these devices. This review focuses on the management of complications of FDS for the treatment of intracranial aneurysms.
Summary: We performed a systematic, qualitative review using electronic databases MEDLINE and Google Scholar. Complications of FDS placement generally occur during the perioperative period.
Key message: Complications associated with FDS may be divided into periprocedural complications, immediate postprocedural complications, and delayed complications. We sought to review these complications and novel management strategies that have been reported in the literature.
Purpose: We assess the impact of retrievable stent (RS) compared to first-generation devices on in-hospital mortality and disability in patients with acute ischemic stroke (AIS).
Methods: Using the National Inpatient Sample, data were obtained for patients with a primary diagnosis of AIS who underwent mechanical thrombectomy (MT) and were admitted to US hospitals between 2010 and 2014. Two time periods were compared: 2010-2012 (pre-RS Food and Drug Administration [FDA] approval) and 2013-2014 (post-RS FDA approval). Disability level was used to classify outcomes as minimal disability, moderate to severe disability, or in-hospital mortality. Weighted, multivariable logistic regression was used to assess the association between MT device type and disability.
Results: A total of 2,443,713 weighted patients admitted with AIS were identified; 148,923 (4.9%) of these received intravenous tissue plasminogen activator; and 23,719 (0.8%) underwent MT. In multivariable logistic regression analysis, the odds of in-hospital mortality decreased (OR 0.69, 95% CI 0.59-0.82) in the post-RS time-period compared with pre-RS time. The odds of moderate-to-severe disability decreased (OR 0.88, 95% CI 0.73-1.06) compared with minimal disability. In-hospital mortality rates decreased successively over the 4 years in the MT-treated patients (p < 0.001).
Conclusions: The FDA approval of RS technology after 2012 was associated with decreased in-hospital mortality when compared with the 3-year interval prior. These findings provide an indication that the RCT data on the efficacy of RS technology are translating into improved real-world outcomes.
Background: Traditionally, patients undergoing acute ischemic strokes were candidates for mechanical thrombectomy if they were within the 6-h window from onset of symptoms. This timeframe would exclude many patient populations, such as wake-up strokes. However, the most recent clinical trials, DAWN and DEFUSE3, have expanded the window of endovascular treatment for acute ischemic stroke patients to within 24 h from symptom onset. This expanded window increases the number of potential candidates for endovascular intervention for emergent large vessel occlusions and raises the question of how to efficiently screen and triage this increase of patients.
Summary: Abbreviated pre-hospital stroke scales can be used to guide EMS personnel in quickly deciding if a patient is undergoing a stroke. Telestroke networks connect remote hospitals to stroke specialists to improve the transportation time of the patient to a comprehensive stroke center for the appropriate level of care. Mobile stroke units, mobile interventional units, and helistroke reverse the traditional hub-and-spoke model by bringing imaging, tPA, and expertise to the patient. Smartphone applications and social media aid in educating patients and the public regarding acute and long-term stroke care.
Key messages: The DAWN and DEFUSE3 trials have expanded the treatment window for certain acute ischemic stroke patients with mechanical thrombectomy and subsequently have increased the number of potential candidates for endovascular intervention. This expansion brings patient screening and triaging to greater importance, as reducing the time from symptom onset to decision-to-treat and groin puncture can better stroke patient outcomes. Several strategies have been employed to address this issue by reducing the time of symptom onset to decision-to-treat time.
Introduction: Tandem vertebral ostial disease with acute intracranial vertebrobasilar occlusion with contralateral vertebral occlusion or hypoplasia presents a unique challenge to the interventionalist.
Methods: The authors queried a prospectively maintained institutional endovascular database from August 2013 to June 2018 for cases of endovascularly treated acute tandem vertebrobasilar occlusions in the presence of contralateral vertebral occlusive disease or hypoplasia. Demographic and presentation data, the technique, results, and clinical outcome were extracted.
Results: Tandem recanalization was attempted and achieved in 5 patients with a thrombolysis in cerebral infarction (TICI) 3 result in 4 patients and a TICI 2c result in 1 patient. To facilitate effective manual aspiration thrombectomy for the tandem basilar occlusion, performed in all cases in 1 or 2 passes, the NeuronTM MAX sheath was advanced into the V2 after Dotter or balloon angioplasty of the diseased origin. In cases where the origin cannot be crossed/visualized, the Synchro Helper to Evaluate via Retrograde Passage an Arterial origin (SHERPA) technique, entailing the passage of a microwire retrograde via the hypoplastic contralateral vertebral artery was utilized to delineate the vertebral ostium (n = 2 cases). All but 1 patient had substantial improvement in the National Institutes of Health Stroke Scale score after the procedure.
Conclusion: Recanalization of tandem vertebrobasilar occlusions with contralateral occlusion or hypoplasia is feasible. Intracranial recanalization is facilitated by the passage of a long 6F sheath into V2, and retrograde delineation of an occluded vertebral origin with a microwire may serve as a crucial adjunct.
Background: Strict criteria for recombinant tissue plasminogen activator (rtPA) eligibility are stipulated on licences for use in ischaemic stroke; however, practitioners may also add non-standard rtPA criteria. We examined eligibility criteria variation in 3 English-speaking countries including use of non-standard criteria, in relation to rtPA treatment rates.
Methods: Surveys were mailed to 566 eligible hospitals in Australia (AUS), the UK, and the USA. Criteria were pre-classified as standard (approved indication and contraindications) or non-standard (approved warning or researcher "decoy"). Percentage for criterion selection was calculated/compared; linear regression was used to assess the association between use of non-standard criteria and rtPA treatment rates, and to identify factors associated with addition of non-standard criteria.
Results: Response rates were 74% AUS, 65% UK, and 68% USA; mean rtPA treatment rates were 8.7% AUS, 12.7% UK, and 8.7% USA. Median percentage of non-standard inclusions was 33% (all 3 countries) and included National Institutes of Health Stroke Scale (NIHSS) scores > 4, computed tomography (CT) angiography documented occlusion, and favourable CT perfusion. Median percentage of non-standard exclusions was 25% AUS, 28% UK, and 60% USA, and included depressed consciousness, NIHSS > 25, and use of antihypertensive infusions. No AUS or UK sites selected 100% of standard exclusions.
Conclusions: Non-standard criteria for rtPA eligibility were evident in all three countries and could, in part, explain comparably low use of rtPA. Differences in the use of standard criteria may signify practitioner intolerance for those derived from original efficacy studies that are no longer relevant.
Background/aims: Endovascular treatment improves the outcomes of patients presenting with acute large vessel occlusions. Isolated proximal carotid occlusions presenting with hemodynamic ischemic stroke may probably also benefit from endovascular treatment. We aimed to assess the clinical and radiological data findings on patients who underwent endovascular treatment for acute ischemic stroke related to an isolated cervical carotid artery occlusion.
Methods: Of a consecutive series of 223 patients who were admitted with acute ische-mic stroke and were treated by thrombectomy, we included 9 patients with isolated cervical internal carotid occlusions.
Results: The mean baseline National Institutes of Health Stroke Scale (NIHSS) score was 11.8. Complete carotid recanalization was achieved in 5 of the 9 patients (55.5%). In 2 patients, vertebral angioplasty was performed to improve the collateral flow. All patients had a modified Thrombolysis in Cerebral Infarction (mTICI) score of 3 at the end of the procedures. A good neurological outcome, defined as a modified Rankin Scale score ≤2 at the 3-month follow-up, was observed in 6 patients (66.7%). No symptomatic intracranial hemorrhages or deaths occurred during the 3 months of follow-up.
Conclusions: The endovascular recanalization of isolated cervical carotid occlusions presenting with acute ischemic stroke symptoms is feasible. Because isolated cervical carotid occlusions are associated with hemodynamic ischemic symptoms, if carotid recanalization cannot be achieved, stenting other cervical arteries' stenoses, with a focus on intracranial flow improvement, appears to be a reasonable strategy. Large controlled studies are necessary to assess the safety and efficacy of recanalization of acute isolated cervical carotid occlusions.
Background: "Remote aspiration," using suction from the proximal internal carotid artery (ICA) to open terminus occlusions, has been reported in small case series. However, it remains unclear whether remote aspiration is feasible for middle cerebral artery occlusions in the setting of potential inflow from communicating arteries. We performed an in vitro study to assess whether suction applied at various locations proximal to an occlusion could successfully aspirate the clot.
Methods: A glass model of 4 mm inner diameter (ID) with 1 mm distal narrowing and 2 mm side branch to simulate a communicating artery was constructed. A proximal side branch was placed to simulate inflow from the proximal ICA. The impact of three different-sized catheters (ID 0.088, 0.070, and 0.056 in) on histologically different (red blood cell-cell rich, fibrin-rich, and mixed) clot analogues was tested with the catheter tip placed remotely either distal or proximal to the collateral branch. Aspiration was attempted with (1) open system (flow in both the ICA and the collateral branch, (2) flow arrest with open collateral (no flow in the ICA, but flow in the collateral branch), and (3) closed system (no flow in either the ICA or the collateral branch). The outcome was success or failure of remote aspiration.
Results: For the 0.088-in catheter, remote aspiration was successful in all conditions. For the 0.070-in catheter, remote aspiration was unsuccessful without proximal flow arrest, but was successful in all other scenarios. For the 0.056-in catheter, remote aspiration was successful only with complete flow arrest.
Conclusions: In a noncollapsible system, remote aspiration can be successfully achieved even in the setting of prominent branch arteries by using relatively large aspiration catheters. Proximal flow arrest may facilitate successful remote aspiration for some catheter sizes.
Background: Successful reperfusion after endovascular thrombectomy (EVT) correlates with good outcome. However, radiographic reperfusion does not always translate into good clinical outcomes even if the reperfusion occurs early after the stroke onset. Reasons for neurological worsening (NW) are thought to be many, such as progression of the stroke, hemorrhagic conversion post tissue plasminogen activator and/or EVT, and procedural complications such as vessel dissection or perforation, distal emboli, and re-occlusion. Data on patients worsening in the acute phase after EVT are limited.
Objective: We studied the factors associated with acute NW and also identified the predictors of NW after EVT and its association with poor outcome at discharge.
Methods: A retrospective cohort from a single comprehensive stroke center includes patients with acute ischemic stroke and large vessel occlusion in anterior and posterior circulation who presented between December 2014 and May 2017 and received EVT were reviewed. Primary outcome was defined as acute NW defined as change in NIHSS ≥4 from baseline in the first 24 h after EVT. Secondary outcome were modified Rankin scale (mRS) 0-2 at discharge and final infarct volume. Univariate and multivariate analyses were performed to evaluate clinical and radiographic variables independently correlating with NW after EVT. Receiver operating curve analysis was also performed to identify predictors.
Results: 178 patients were included in the analysis, 26 (14.7%) met the criteria for acute NW. For these 178 patients, the median age was 63 (IQR 53-74, range 26-89), baseline median NIHSS was 19 (IQR 14-24, range 5-37), ASPECTS was 8 (IQR 7-9, range 4-10), admission median systolic blood pressure (SBP) was 150 (IQR 131-170, range 94-287), and initial median blood glucose (BG) was 123 (IQR 106-157, range 69-433). The most common reasons for worsening were progression of the stroke (42.3%) and reperfusion injury PH-2 (26.9%) (p < 0.0001). Univariate logistic analysis showed that race, ASPECTS, collateral score, diabetes mellitus, admission SBP, and admission BG were associated with acute NW. In multivariate analysis, only admission BG (OR 1.00, CI 1.00-1.01, p = 0.04) was found to have a significant association with acute NW. We ran a prediction analysis for variables and found the area under the curve to be 0.75. Finally, there was strong association between NW and poor outcome at discharge (MRS 3-6, p < 0.01) by Fisher's exact test. About 46.1% in the NW group died during hospitalization compared to 10% in the non-NW group (p < 0.0001).
Conclusion: Our single-center retrospective cohort result is limited by small sample size. It showed that high admission BG is an independent predictor of NW after EVT and ultimately leads to poor outcome.
Background: Recent reports have raised various concerns about the risk of vessel wall injury while withdrawing current laser-cut stent retrievers during active strut apposition to the vessel walls. The development of braided thrombectomy assist devices in conjunction with aspiration systems may be gentler on the fragile brain vessels and more optimized with regard to the radial force (RF) for vessel diameters of proximal (M1) and distal (M2) large vessel occlusions (LVOs).
Methods: Mechanical bench testing of the RF was performed using a radial compression station mounted on a tensile testing machine. The total RF in newtons (N) generated in vessels with diameters ranging from 2.25 to 3 mm as seen in proximal LVOs (∼M1), and in vessel diameters ranging from 1.5 to 2.24 mm as seen in distal LVOs (∼M2), was measured. The outer diameter of each stent was recorded, and an RF ≤1 N was grouped as "low," while an RF >1 N was grouped as "high" for this analysis.
Results: The total RFs of all laser-cut stent retrievers were all higher in the simulated M2 vessels (>1 N) than in the M1 vessels (<1 N), whereas the total RFs of the braided thrombectomy assist devices were uniformly low in both the simulated M1 and the simulated M2 vessels.
Conclusions: Novel braided thrombectomy assist devices in conjunction with aspiration systems have lower RFs than existing laser-cut stent retrievers in M1 and M2 vessel diameters. Further in vivo studies are needed to delineate the impact of lowering the RF on vessel wall integrity.