Update on Neurointerventional Therapy for the Treatment of Acute Cerebral Ischemia.

Mechanical thrombectomy (MT) is a minimally invasive, fluoroscopically guided procedure to remove clots from the arteries in the head and neck. The procedure can be performed very quickly and effectively, with low complication rates, as techniques and technology have advanced in recent years. MT is among the most efficacious procedures performed today, with a very low number needed to treat (NNT) to impact outcomes. Expanded indications for MT include patients with large core infarcts, extended time windows from stroke onset, more distal occlusions, and milder symptoms. Trials have shown a significant benefit of MT in terms of reduced disability in nearly every patient population studied.

Improved catheter delivery for aspiration thrombectomy using Tenzing 7 ledge reducing catheter and FreeClimb 70.

PURPOSE: Previous comparative mechanical thrombectomy device trials reported a substantial crossover rate from first-line aspiration to stent-retriever thrombectomy. A specialized delivery catheter may help track large-bore aspiration catheters to target occlusions. We report our multicenter experience of aspiration thrombectomy of intracranial large vessel occlusions using the FreeClimbTM 70 and Tenzing® 7 delivery catheter (Route 92, San Mateo, CA). METHODS: After local Institutional Review Board approval, we retrospectively reviewed the clinical, procedural, and imaging data of patients who underwent mechanical thrombectomy with the FreeClimb 70 and Tenzing 7. RESULTS: FreeClimb 70 was successfully delivered using Tenzing 7 to target occlusion in 30/30 (100%) patients (18 M1, 6 M2, 4 ICA-terminus, and 2 basilar artery occlusions), without the use of a stent-retriever for anchoring. In 21/30 (70%) cases, a leading microwire was not needed to advance the Tenzing 7 to the target. Median (interquartile range) time from groin puncture to first pass was 12 (interquartile range 8-15) minutes. Overall first pass effect, or first pass effect (modified thrombolysis in cerebral ischemia 2C-3), was achieved 16/30 (53%). For M1 occlusions, first pass effect was 11/18 (61%). Successful reperfusion (modified thrombolysis in cerebral ischemia ≥ 2B) was achieved in 29/30 (97%) cases after a median of 1 pass (interquartile range 1-3). Median groin puncture to reperfusion time was 16 (interquartile range 12-26) minutes. There were no procedural complications or symptomatic intracranial hemorrhage. Average improvement in National Institutes of Health Stroke Scale at discharge was 6.6 ± 7.1. There were three patient deaths (renal failure, respiratory failure, and comfort care). CONCLUSIONS: Initial data support the use of Tenzing 7 with FreeClimb 70 catheter for reliable access to rapid, effective, and safe aspiration thrombectomy of large vessel occlusions.

The SMART Registry: Long-Term Results on the Utility of the Penumbra SMART COIL System for Treatment of Intracranial Aneurysms and Other Malformations.

Introduction: Penumbra SMART COIL® (SMART) System is a novel generation embolic coil with varying stiffness. The study purpose was to report real-world usage of the SMART System in patients with intracranial aneurysms (ICA) and non-aneurysm vascular lesions. Materials and Methods: The SMART Registry is a post-market, prospective, multicenter registry requiring ≥75% Penumbra Coils, including SMART, PC400, and/or POD coils. The primary efficacy endpoint was retreatment rate at 1-year and the primary safety endpoint was the procedural device-related serious adverse event rate. Results: Between June 2016 and August 2018, 995 patients (mean age 59.6 years, 72.1% female) were enrolled at 68 sites in the U.S. and Canada. Target lesions were intracranial aneurysms in 91.0% of patients; 63.5% were wide-neck and 31.8% were ruptured. Adjunctive devices were used in 55.2% of patients. Mean packing density was 32.3%. Procedural device-related serious adverse events occurred in 2.6% of patients. The rate of immediate post-procedure adequate occlusion was 97.1% in aneurysms and the rate of complete occlusion was 85.2% in non-aneurysms. At 1-year, the retreatment rate was 6.8%, Raymond Roy Occlusion Classification (RROC) I or II was 90.0% for aneurysms, and Modified Rankin Scale (mRS) 0-2 was achieved in 83.1% of all patients. Predictors of 1-year for RROC III or retreatment (incomplete occlusion) were rupture status (P < 0.0001), balloon-assisted coiling (P = 0.0354), aneurysm size (P = 0.0071), and RROC III immediate post-procedure (P = 0.0086) in a model that also included bifurcation aneurysm (P = 0.7788). Predictors of aneurysm retreatment at 1-year was rupture status (P < 0.0001). Conclusions: Lesions treated with SMART System coils achieved low long-term retreatment rates. Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier NCT02729740.

Radial artery neuro guide catheter entrapment during mechanical thrombectomy for acute ischemic stroke: Rescue brachial plexus block.

To our knowledge, radial artery catheter entrapment during mechanical thrombectomy for acute ischemic stroke using an 8 F neuro guiding catheter (.088 in ID) and successful use of a brachial plexus block has not been described in the literature. In this technical note, we describe a patient that underwent rapid and successful radial access mechanical thrombectomy for an acute right middle cerebral artery occlusion, however, during withdrawal of the Balt Ballast 0.088 inch long sheath (Balt USA, Irvine, CA, USA), radial/brachial artery entrapment was encountered. We describe a modified step-wise approach to previously published online article by Pitta et al. from 2017 SCAI communication in the management of catheter entrapment and describe the technique for ultrasound guided brachial plexus block, which helped avoid need for surgical removal.

Basilar artery perforator aneurysms (BAPAs): review of the literature and classification.

Basilar artery perforator aneurysms (BAPAs) are an uncommon subtype of perforating artery aneurysms, with only 18 published cases since their initial description in 1996 by Ghogawala et al To date, there are only seven published cases of ruptured BAPAs treated using endovascular techniques. Given the rarity of these aneurysms, the natural history and ideal approach to treatment has not been established. We describe a new endovascular approach to treating these aneurysms using staged telescoping stents, summarize all published cases of BAPAs, and present a unique classification system to enable future papers to standardize descriptions.

Mechanical thrombectomy for pediatric acute ischemic stroke: review of the literature.

OBJECTIVE: Given recent strongly positive randomized controlled adult mechanical thrombectomy trials, we sought to perform a comprehensive review of available literature on IA pediatric stroke intervention, with a focus on modern mechanical devices. METHODS: PubMed search for pediatric patients undergoing IA treatment of acute ischemic stroke (AIS) using modern devices between 2008 and 2015. 29 patients were included in this analysis. RESULTS: Average age was 10.3 years, 74.1% male, middle cerebral and basilar arteries represented 89.6% of 36 occluded vessels, and average pediatric stroke scale score of 18.1. Average time from symptom onset to intervention was 8.8 hours and 13.8% of patients received IV tissue plasminogen activator prior to mechanical thrombectomy. Stent retrievers were used in 58.6% of cases, the Penumbra system in 34.5%, and the Merci device in 27.6%. Modified Thrombolysis In Cerebral Infarction 2b/3 recanalization was achieved in 75.9% of cases. There were no major adverse events related to the intervention, although one procedure was associated with device malfunction without a definite change in long-term outcome. The average modified Rankin Scale (mRS) score was <1 (0.86) at the longest available follow-up period, based on clinical description or provided mRS score. CONCLUSIONS: This study suggests that mechanical thrombectomy in pediatric patients presenting with high pediatric NIH Stroke Scale scores and proximal large vessel occlusion is associated with high recanalization rates and excellent clinical outcome, although this is a retrospective review and the sample size is too small to make any definitive conclusions. This study provides class IVC evidence that endovascular treatment of pediatric AIS increases the chance of a good clinical outcome.

Radial access for cerebrovascular procedures: Case report and technical note.

BACKGROUND: Advantages of radial access over brachial/axillary or femoral access have been well described for several decades and include decreased cost, patient preference, and decreased major access site complications. Despite these advantages, radial access is rarely employed or even considered for neurointerventional procedures. This attitude should be reconsidered given several recent large, randomized, controlled trials from the cardiovascular literature proving that radial access is associated with statistically lower costs, decreased incidence of myocardial infarctions, strokes, and even decreased mortality. Radial access is now considered the standard of care for percutaneous coronary interventions in most US centers. Although radial access has been described for neurovascular procedures in the past, overall experience is limited. The two major challenges are the unique anatomy required to access the cerebral vasculature given very acute angles between the arm and craniocervical vessels and limitations in available technology. METHODS: We present a simplified approach to radial access for cerebrovascular procedures and provide a concise step-by-step approach for patient selection, ultrasound-guided single-wall access, recommended catheters/wires, and review of patent hemostasis. Additionally, we present a complex cerebrovascular intervention in which standard femoral access was unsuccessful, while radial access was quickly achieved to highlight the importance of familiarity with the radial approach for all neurointerventionalists. RESULTS: We have found that the learning curve is not too steep and that the radial access approach can be adopted smoothly for a large percentage of diagnostic and interventional neuroradiologic procedures. CONCLUSIONS: Radial access should be considered in all patients undergoing a cerebrovascular procedure.

Particle embolization of the bilateral superior and inferior alveolar arteries for life threatening dental socket hemorrhage.

Particle embolization for epistaxis and intra-oral hemorrhage are performed on an as needed basis by neurointerventionalists. A case is presented of massive oral hemorrhage associated with end stage liver disease coagulopathy after tooth extraction of bilateral maxillary and mandibular molars. A man in his fifties with end stage liver disease who presented for evaluation of a syncopal episode was determined to be in hemorrhagic shock from 2 days of persistent oral bleeding after elective tooth extractions. Conservative management with multiple blood transfusion products, packing and vasoconstrictive spray was ineffective. Microcatheter angiograms of the alveolar arteries demonstrated blood and contrast pooling within the sockets of the extracted teeth. Selection of the bilateral supplying alveolar and inferior alveolar artery branches was achieved followed by polyvinyl alcohol particle embolization (250-355 µm). Polyvinyl alcohol particle embolization of dental socket hemorrhages is technically feasible and effective.

Centenarian middle cerebral artery occlusion treated with intra-arterial mechanical embolectomy.

Advanced age, arbitrarily defined as over 80 years, has been an exclusion criterion in many clinical trials for the treatment of acute ischemic stroke. The oldest person, to our knowledge, treated for acute ischemic stroke with intra-arterial therapy is presented and, importantly, this patient was excluded from intravenous tissue plasminogen activator due to an advanced age of 100 years and arrival in our emergency department within the 3-4.5 h time window. Utilizing an MRI based protocol to assess the risk-benefit ratio, treatment by intra-arterial mechanical embolectomy was commenced resulting in middle cerebral artery recanalization at 6 h 30 min. The patient improved, and ultimately returned to a baseline modified Rankin Scale score of 3. With careful selection, elderly patients may benefit from acute stroke therapies and may be considered on a case by case basis.

Combined surgical and endovascular approach to a complex dural arteriovenous fistula involving the superior sagittal sinus and torcula.

A complex dural arteriovenous fistula (dAVF) may require complex treatment strategies to achieve successful obliteration. We describe a combined open surgical and endovascular approach to a dAVF involving the superior sagittal sinus (SS) and torcula. A 68-year-old male with Factor V Leiden mutation presented with altered mental status from venous hypertension secondary to a complex, high-flow Borden III dAVF with internal carotid and bilateral external carotid artery feeders draining into the SS and torcula. Because the venous channel to the recipient SS at the point of convergence of the AV shunting was not accessible transfemorally due to venous stenosis, a surgical strategy using a midline burrhole for direct catheterization of the SS was devised. A balloon was inflated in the sinus during arterial embolization. This technique was effective in achieving embolization of multiple arterial feeders via a single vessel injection. Covered Atrium iCasts were introduced in a telescoping fashion after angioplasty of the posterior SS-torcular junction in an attempt to functionally occlude further AV shunting. Postembolization angiography revealed greatly diminished AV shunting with improved intracranial transit time and retrograde cortical venous drainage. The patient was maintained on anticoagulation and made a complete recovery following the intervention; however, he subsequently deteriorated acutely, and died on postprocedure day 4. This case illustrates the difficulties associated with treating a complex AVF, describes a temporizing solution, and reports a potential complication from placing a covered stent in the SS.

Merci retrievers as access adjuncts for reperfusion catheters: the grappling hook technique.

BACKGROUND: Expeditious, stable access in acute ischemic stroke is foundational for mechanical revascularization. Proximal vascular tortuosity and unfavorable anatomy may impede the access necessary for revascularization, particularly when large-caliber catheters are used. We describe an approach using the Merci retriever to gain stable catheter access for aspiration. OBJECTIVE: To assess the technical feasibility of using the Merci retriever system as an access adjunct in acute ischemic stroke and tortuous ophthalmic segment anatomy. METHODS: The acute ischemic stroke database was queried, and 3 patients presenting with acute ischemic stroke and tortuous proximal anatomy who were treated with mechanical thrombectomy and the Merci retriever as an access adjunct were identified. Patient charts and procedure reports were reviewed. RESULTS: In each of the patients, the ophthalmic segment of the internal carotid artery proved difficult to navigate. An appropriately sized Merci retriever was deployed in the M1 segment. Gentle tension on the retriever was applied, altering the angle at which the aspiration catheter navigated the ophthalmic segment, affording rapid access past the ophthalmic artery origin and into the target vessel. The 18 L microcatheter and retriever were withdrawn, followed by aspiration and clot maceration with the Penumbra aspiration system. CONCLUSION: Tortuous proximal anatomy may impede access to an occluded vessel. Use of tension on a deployed Merci retriever straightens the course of the wire, changing the angle that the aspiration catheter makes with the vessel. In the setting of unfavorable anatomy, this technique may be used to advance an aspiration catheter to the target lesion.

Balloon-augmented carotid artery sacrifice with Onyx: a proof of concept study in a swine model.

INTRODUCTION: Carotid sacrifice remains a valuable tool in the treatment of select vascular lesions. Neurointerventionalists have relied on coil embolization as their primary means of carotid sacrifice, a procedure that can be lengthy and expensive with long fluoroscopy times. We investigated a novel technique for carotid sacrifice in a swine model using temporary balloon occlusion to achieve proximal flow arrest in the carotid artery while embolizing the vessel with a liquid embolic agent. METHODS: A total of 10 common carotid artery sacrifices were performed in pigs under fluoroscopic guidance. Various balloons were employed to achieve near total proximal flow arrest to allow an Onyx cast to accumulate in the target vessel. RESULTS: The technique for sacrifice was modified during the experiment with the final procedures yielding successful sacrifice using Onyx through a dimethylsulfoxide-tolerant catheter (Echelon 14) with the assistance of two fibered coils and a 5 mm × 30 mm Hyperglide balloon resulting in a 2.5 cm long cast. CONCLUSION: Carotid artery sacrifice using commercially available non-adhesive liquid embolic agents is feasible with balloon assistance, allowing for reduced radiation and material costs. Coils may be beneficial in providing an anchor point for liquid embolic deposition, as well as reducing the volume of liquid embolysate required to achieve vessel occlusion.

Embolic protection devices and the Penumbra 054 catheter: utility in tandem occlusions in acute ischemic stroke.

BACKGROUND: Tandem proximal and distal occlusions in the setting of an acute stroke are therapeutic challenges. Treating either lesion first has its respective shortcomings. An approach is described which may lessen the probability of distal embolic events during emergency carotid angioplasty and stenting during an acute stroke, and simplify access to both a distal and proximal lesion. CLINICAL PRESENTATION: A 58-year-old man presented with waxing and waning neurological examination with an NIH Stroke Scale varying from 4 to 21. CT angiography demonstrated a left internal carotid artery occlusion at its origin and a left middle cerebral artery occlusion. The CT scan failed to demonstrate significant ischemic changes so the patient was brought to angiography for treatment under conscious sedation. INTERVENTION: Triaxial access into the distal middle cerebral artery was achieved followed by brief aspiration and clot maceration by opening the vessel completely. An embolic protection device was deployed through the intermediate catheter which was subsequently removed. Stenting and angioplasty were then performed, followed by removal of the embolic protection device which had visibly trapped debris. CONCLUSION: Embolic protection devices may have a role in the emergency treatment of proximal occlusions in the setting of an acute ischemic stroke. Safe deployment through an occluded vessel may be assisted by use of an intermediate catheter. The Penumbra 054 catheter may be used both to aspirate the distal thrombus and to house the embolic protection device as it is advanced past a proximal occlusion.

Stenting of a symptomatic long-segment extracranial vertebral artery occlusion.

We present a 56-year-old man who presented with bilateral vertebral artery occlusions and recurrent transient ischemic attacks and strokes despite maximal medical therapy. A long-segment extracranial right vertebral occlusion was noted and successfully reconstructed with four drug-eluting stents. The patient has been symptom free for 3 months and does not exhibit restenosis on follow-up angiography. Stenting and angioplasty of a long-segment vertebral artery occlusion is technically feasible in select cases.

An analysis of inflation times during balloon-assisted aneurysm coil embolization and ischemic complications.

BACKGROUND AND PURPOSE: The introduction of balloon remodeling has revolutionized the approach to coiling of wide-neck aneurysms. We studied the effects of balloon inflation during coil embolization on ischemic complications. METHODS: A retrospective review was undertaken of the most recent 147 patients undergoing balloon remodeling for unruptured intracranial aneurysm coil embolization at a single institution (81 balloon, 66 unassisted). All underwent postprocedural MRI. RESULTS: Among patients in the "balloon" group, the mean total inflation time was 18 minutes (range, 1-43), a mean number of inflations of 4 (range, 1-9), a mean maximum single inflation time of 7 minutes (range, 1-19), a mean reperfusion time of 2.2 minutes between inflations, and an average procedure time of 2 hours and 10 minutes. Asymptomatic diffusion-weighted imaging abnormalities were detected on postprocedural MRI in 21.5% of patients and symptomatic lesions were identified in 3.8%. Both silent and symptomatic ischemic rates were similar in the internal control group. Patients with ischemic findings were older and more likely have diabetes; no differences were found with respect to total balloon inflation time, number of inflations, maximum inflation time, or reperfusion times. CONCLUSIONS: We found no significant relationship between balloon inflation practices and ischemic events. Older and diabetic patients were more likely to have ischemic events develop.

The versatile distal access catheter: the Cleveland Clinic experience.

BACKGROUND: Vascular access is fundamental to any endovascular intervention. Concentric Medical has developed the Outreach Distal Access Catheter (DAC), which affords stable access at the target vessel modulating the forces at play within the thrombectomy device complex. The DAC is a device with novel access characteristics useful in a host of other types of clinical scenarios. OBJECTIVE: To review our experience with the DAC family of devices, the theory, and method of use. METHODS: A retrospective review of all cases in which the DAC was used during the period 2008 to 2010 was conducted and the cases classified by indication. Catheter-related complications were recorded. The use of the DAC in a variety of settings including intracranial stenting, aneurysm coil embolization, and arteriovenous malformation embolization is described. RESULTS: The DAC was used in 103 procedures performed in 93 patients between August 2008 and February 2010. Indications included acute stroke, treatment of intracranial atherosclerosis, vasospasm therapy, arteriovenous malformation embolization, and aneurysm embolization. In those procedures, 113 catheters were used. No complications directly attributable to DAC use were identified. CONCLUSION: The DAC is useful for gaining access to the cerebral vasculature, especially in patients with significant tortuosity or when re-access of distal vasculature is required multiple times.

Initial experience with angioplasty of symptomatic M2 MCA atheromatous lesions.

BACKGROUND AND PURPOSE: Symptomatic intracranial atherosclerosis has been associated with a high rate of recurrent stroke. The safety of treatment of more distal atheromatous lesions with angioplasty has not been systematically reported. METHODS: We retrospectively reviewed our institutional database for all patients treated with intracranial angioplasty and stenting from January 2008 to July 2009. A total of 108 patients were treated and five patients were treated with angioplasty for a symptomatic M2 middle cerebral artery stenosis with fluctuating neurological examinations. We report our experience with these patients. RESULTS: All five patients underwent technically successful treatment with a reduction of the stenosis to <50%. There were no periprocedural complications and all patients had cessation of their clinical fluctuations. Two patients were found to have symptomatic restenosis with one patient suffering a disabling stroke at 5 months and the second patient a transient ischemic attack at 4 months who was subsequently successfully re-treated with angioplasty and stent placement. CONCLUSIONS: Angioplasty of M2 MCA lesions is technically feasible in our cohort of neurologically unstable patients, but the durability of this treatment will require more extensive study.