Technical and clinical success after venous sinus stenting for treatment of idiopathic intracranial hypertension using a novel guide catheter for access: Case series and initial multi-center experience.

INTRODUCTION: Venous sinus stenting is a well established alternative to cerebrospinal fluid diversion for the treatment of idiopathic intracranial hypertension (IIH) with associated venous sinus stenosis. During this procedure, distal guide catheter placement within the venous sinuses may be desirable to facilitate stent delivery. We report our initial experience using the TracStar LDP™ (Imperative Care, Campbell, USA, 0.088-inch inner diameter) as the guide catheter for intracranial access during venous sinus stenting. METHODS: A multi-institutional retrospective chart review of a prospectively maintained IRB-approved database was performed. Consecutive patients who underwent venous sinus stenting from 1/1/2020-9/6/2021 for IIH were included. Patient characteristics, procedural details, TracStar distal reach, outcomes, and complications were collected and analyzed. RESULTS: Fifty-eight patients were included. The mean age was 33.8 years and 93.1% of patients were female. Visual changes prompted evaluation in 86.2% of patients. Stent placement was successful in all patients. The TracStar LDP catheter was advanced to the location of stent placement in 97.9% of cases in which it was attempted. The large 0.088-inch inner diameter lumen enabled compatibility with all desired stent sizes ranging from six to 10 millimeters. Gradient pressure across transverse sinus stenosis dropped from an average of 19.5 mmHg pre-procedure to 1.7 mmHg post-stent placement (p < 0.001). Clinical improvement was achieved in 87.9% (51/58) of patients. There were no catheter-related complications. CONCLUSION: The TracStar LDP is a safe and effective access platform for reaching treatment locations in patients who present with idiopathic intracranial hypertension and who are candidates for venous sinus stent placement.

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.

Initial clinical experience with the ADAPT technique: A direct aspiration first pass technique for stroke thrombectomy.

BACKGROUND: The development of new revascularization devices has improved recanalization rates and time but not clinical outcomes. We report our initial results with a new technique utilizing a direct aspiration first pass technique with a large bore aspiration catheter as the primary method for vessel recanalization. METHODS: A retrospective evaluation of a prospectively captured database of 37 patients at six institutions was performed on patients where the ADAPT technique was utilized. The data represent the initial experience with this technique. RESULTS: The ADAPT technique alone was successful in 28 of 37 (75%) cases although six cases had large downstream emboli that required additional aspiration. Nine cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalization. The average time from groin puncture to at least Thrombolysis in Cerebral Ischemia (TICI) 2b recanalization was 28.1 min, and all cases were successfully revascularized. TICI 3 recanalization was achieved 65% of the time. On average, patients presented with an admitting National Institutes of Health Stroke Scale (NIHSS) score of 16.3 and improved to an NIHSS score of 4.2 by the time of hospital discharge. There was one procedural complication. DISCUSSION: This initial experience highlights the fact that the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple and effective approach to acute ischemic stroke thrombectomy. Utilizing the latest generation of large bore aspiration catheters in this fashion has allowed us to achieve excellent clinical and angiographic outcomes.

Treatment of blood blister aneurysms of the internal carotid artery with flow diversion.

BACKGROUND: Blood blister aneurysms (BBA) are a rare subset of intracranial aneurysms that represent a therapeutic challenge from both a surgical and endovascular perspective. OBJECTIVE: To report multicenter experience with flow diversion exclusively for BBA, located at non-branching segments along the anteromedial wall of the supraclinoidal internal carotid artery (ICA). METHODS: Consecutive cases of BBA located at non-branching segments along the anteromedial wall of the supraclinoidal ICA treated with flow diversion were included in the final analysis. RESULTS: 49 patients with 51 BBA of the ICA treated with devices to achieve the flow diversion effect were identified. 43 patients with 45 BBA of the ICA were treated with the pipeline embolization device and were included in the final analysis. Angiographic follow-up data were available for 30 patients (32 aneurysms in total); 87.5% of aneurysms (28/32) showed complete obliteration, 9.4% (3/32) showed reduced filling, and 3.1% (1/32) persistent filling. There was no difference between the size of aneurysm (≤2 mm vs >2 mm) or the use of adjunct coiling and complete occlusion of the aneurysm on follow-up (P=0.354 and P=0.865, respectively). Clinical follow-up data were available for 38 of 43 patients. 68% of patients (26/38) had a good clinical outcome (modified Rankin scale score of 0-2) at 3 months. There were 7 (16%) immediate procedural and 2 (5%) delayed complications, with 1 case of fatal delayed re-rupture after the initial treatment. CONCLUSIONS: Our data support the use of a flow diversion technique as a safe and effective therapeutic modality for BBA of the supraclinoid ICA.

Safety and effectiveness of large volume coils in the treatment of small aneurysms.

BACKGROUND AND PURPOSE: Large volume soft design coils facilitate quicker aneurysm filling and high packing density. Our purpose was to analyze the feasibility, safety, and effectiveness of the Penumbra Coil 400 (PC400) system in the treatment of small aneurysms. MATERIALS AND METHODS: A retrospective analysis of prospective data collected at three different centers was performed on consecutive aneurysms <10 mm treated with the PC400 system. A total of 92 aneurysms were included in the study. Feasibility, procedure safety, angiographic and clinical results, and follow-up results were evaluated. RESULTS: Mean aneurysm size was 5.8±2.0 mm. An average of 2.5±1.3 coils with a mean length of 18±16 cm per aneurysm was used, resulting in a mean packing density of 45.6±14.4%. The thromboembolic event rate was 3.3% and no procedural aneurysm rupture was observed. Immediate adequate occlusion was achieved in 66% of aneurysms. During a mean follow-up period of 7.4 months the number of adequate occlusions increased to 91%. CONCLUSIONS: Large volume PC 400 coils are safe and effective in the treatment of small aneurysms with a low thromboembolic complication rate and no hemorrhagic events. High packing densities are achieved with a low average number of coils used per aneurysm treated. The aneurysms demonstrated progressive occlusion over time, which probably suggests stability in the long term.

Proximal to distal approach in the treatment of tandem occlusions causing an acute stroke.

INTRODUCTION: A tandem occlusion is a rare presentation of acute stroke that involves an occlusion of the internal carotid artery at the bifurcation with an intracranial middle cerebral artery occlusion. This study describes the experience at our institution in treating tandem occlusions with a proximal to distal approach in the acute stroke setting. METHODS: A retrospective review of acute strokes caused by tandem occlusions requiring thrombectomy were performed. RESULTS: 16 cases were identified with a mean National Institutes of Health Stroke Scale score at presentation of 13.1 ± 3.9. The proximal occlusion was crossed initially with a microwire in all cases. All carotid occlusions were treated with stenting, and intracranial vessel thrombectomy was performed with a variety of devices. Procedure related complications occurred in two (12.5%) patients. Eight patients (50%) achieved a good outcome (modified Rankin Scale score of 0-2). CONCLUSIONS: A tandem occlusion of the carotid artery at the bifurcation with a concomitant intracranial occlusion is a relatively rare and complex presentation of acute stroke. We have found that addressing the proximal lesion first and covering it with a stent prior to performing distal thrombectomy appears to be a safe and effective option in the treatment algorithm.

Impact of the ASPECT scores and distribution on outcome among patients undergoing thrombectomy for acute ischemic stroke.

INTRODUCTION: This study investigates whether the Alberta Stroke Program Early CT Score (ASPECTS) quantification is associated with outcome following mechanical thrombectomy. OBJECTIVE: To determine whether preintervention non-perfect ASPECT scores involving cortical or subcortical regions and the side of the non-perfect ASPECT score affects outcomes. METHODS: A retrospective review of a prospectively maintained database of patients with acute ischemic stroke involving the anterior circulation who underwent thrombectomy between May 2008 and August 2012 at a single tertiary care center. The device for mechanical thrombectomy used was the penumbra aspiration system (Penumbra Inc, Alameda, California, USA) and the Solitaire stent retriever (ev3, Irvine, California, USA). A 'blinded' neuroradiologist obtained ASPECTS quantification and noted each region demonstrating early changes. RESULTS: 149 patients (51.7% female, mean age 66.1±15.1 years) were included with an average National Institutes of Health Stroke Scale of 16.2±6.7. Patients with non-perfect ASPECT scores on pretreatment imaging were more likely to have a hemorrhagic conversion (p=0.04) evident on post-procedure CT. However, functional outcomes were the same. Patients with both cortical and basal ganglia non-perfect ASPECT scores were more likely to be in a persistent vegetative state or expire. No differences were identified in outcome among patients with left- versus right-sided infarcts affecting the basal ganglia or cortical regions. CONCLUSIONS: These findings support a strategy of selecting candidacy for thrombectomy that does not exclude patients with non-perfect ASPECT scores involving either the basal ganglia or cortical regions. Outcomes were identical among patients with no non-perfect ASPECT scores and those with cortical or subcortical infarcts, despite a higher incidence of hemorrhagic conversion found among those with non-perfect ASPECT scores.

Quantitative longitudinal evaluation of diaschisis-related cerebellar perfusion and diffusion parameters in patients with supratentorial hemispheric high-grade gliomas after surgery.

Decreased cerebral blood volume (CBV) in contralateral cerebellar gray matter (cGM) in conjunction with cerebellar white matter (cWM) damage, consistent with crossed cerebro-cerebellar diaschisis (cCCD) develop following supratentorial hemispheric stroke. In this study, we investigated the longitudinal evolution of diaschisis-related cerebellar perfusion and diffusion tensor-imaging (DTI) changes in patients after surgery for supratentorial brain tumors. Eight patients (M:F 5:3, age 8-22 years) who received surgery for supratentorial high-grade gliomas were evaluated. Initial MRI studies were performed 19-54 days postoperatively, with follow-ups at 2- to 3-month intervals. For each study, parametric maps of the cerebellum were generated and coregistered to T1-weighted images that had been previously segmented for cGM and cWM. Aggregate mean values of CBV, cerebral blood flow (CBF), and fractional anisotropy (FA) were obtained separately for cGM and cWM, and asymmetry indices (AIs) were calculated. Hemodynamic changes were more robust in cGM than in cWM. Seven patients showed decreased perfusion within cGM contralateral to the supratentorial lesion on the first postoperative study, and asymmetry was significant for both CBV (p = 0.008) and CBF (p < 0.01). For CBV, follow-up studies showed a significant trend towards recovery (p < 0.02). DTI changes were more pronounced in cWM. FA values suggested a "paradoxical" increase at initial follow-up, but steadily declined thereafter (p = 0.0003), without evidence of subsequent recovery. Diaschisis-related hemodynamic alterations within cGM appear on early postoperative studies, but CBV recovers over time. Conversely, cWM DTI changes are delayed and progressive. Although the clinical correlates of cCCD are yet to be elucidated, better understanding of longitudinal structural and hemodynamic changes within brain remote from the area of primary insult could have implications in research and clinical rehabilitative strategies.

Hounsfield unit value and clot length in the acutely occluded vessel and time required to achieve thrombectomy, complications and outcome.

INTRODUCTION: Intra-arterial therapy for acute ischemic stroke (AIS) now has an established role. We investigated if Hounsfield Units (HU) quantification on non-contrast CT is associated with ease and efficacy of mechanical thrombectomy and outcomes. METHODS: We retrospectively studied a prospectively maintained database of cases of AIS given intra-arterial therapy between May 2008 and August 2012. Functional outcome was assessed by 90-day follow-up modified Rankin Scale (mRS). Patients were dichotomized based on time to recanalization. HU were calculated on head CT and thrombus location and length were determined on CT angiography. Simple linear regression was used to analyze the association between clot length, average HU and other clinical variables. RESULTS: 141 patients were included. There was no difference in clot length or average HU among patients with good recanalization achieved within 1 h and those in which the procedures extended beyond 1 h. There was no relationship between clot length or density and recanalization. The thrombus length and density were not significantly different between patients with procedural complications and those without. Neither the presence of post-procedure intracranial hemorrhage nor the 90-day mRS was associated with thrombus length or density. CONCLUSIONS: We have not found any significant associations between either thrombus length or density and likelihood of recanalization, time to achieve recanalization, intraprocedural complications, postprocedural hemorrhage or functional outcome at 90 days. These results do not support a predictive value for thrombus quantification in the evaluation of AIS.

Initial clinical experience with the ADAPT technique: a direct aspiration first pass technique for stroke thrombectomy.

BACKGROUND: The development of new revascularization devices has improved recanalization rates and time but not clinical outcomes. We report our initial results with a new technique utilizing a direct aspiration first pass technique with a large bore aspiration catheter as the primary method for vessel recanalization. METHODS: A retrospective evaluation of a prospectively captured database of 37 patients at six institutions was performed on patients where the ADAPT technique was utilized. The data represent the initial experience with this technique. RESULTS: The ADAPT technique alone was successful in 28 of 37 (75%) cases although six cases had large downstream emboli that required additional aspiration. Nine cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalization. The average time from groin puncture to at least Thrombolysis in Cerebral Ischemia (TICI) 2b recanalization was 28.1 min, and all cases were successfully revascularized. TICI 3 recanalization was achieved 65% of the time. On average, patients presented with an admitting National Institutes of Health Stroke Scale (NIHSS) score of 16.3 and improved to an NIHSS score of 4.2 by the time of hospital discharge. There was one procedural complication. DISCUSSION: This initial experience highlights the fact that the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple and effective approach to acute ischemic stroke thrombectomy. Utilizing the latest generation of large bore aspiration catheters in this fashion has allowed us to achieve excellent clinical and angiographic outcomes.

Transfemoral venous approach for Onyx embolization of anterior fossa dural arteriovenous fistulae.

BACKGROUND: Dural arteriovenous fistulae (dAVF) of the anterior fossa have a malignant course since they exclusively drain into cortical frontal veins and warrant aggressive treatment. Classically, these lesions have been treated with microsurgical clipping of the fistulous connection. We describe a transvenous approach for Onyx embolization of these lesions that relies on distal venous access using a flexible new-generation guide catheter. METHODS: A retrospective review was performed of all patients with an anterior fossa dAVF treated at the Medical University of South Carolina since 2010. Charts, procedural records, angiographic images and follow-up were reviewed. Three patients were identified. RESULTS: Transfemoral venous access and distal transvenous sinus access was obtained in a retrograde fashion to at least the level of the right transverse sinus. Once a distal guide catheter position was obtained within the venous sinus system, a microcatheter was advanced into the predominant draining anterior frontal cortical vein in preparation for embolization. Onyx 34 embolization was then initiated from this position with the objective of achieving penetration across the vascular shunt. CONCLUSIONS: Our experience demonstrates that transvenous Onyx embolization offers an effective and safe alternative to the classic neurosurgical treatment of anterior fossa dAVF.

Balloon remodeling for aneurysm coil embolization with the coaxial lumen Scepter C balloon catheter: initial experience at a high volume center.

INTRODUCTION: The use of balloon remodeling allows for the treatment of aneurysms that were previously considered to be poor candidates for coil embolization. The Scepter C (Microvention, Tustin, California, USA) is a novel temporary occlusion balloon system with a dual coaxial lumen catheter. The design accommodates a more steerable 0.014 inch guidewire with improved control for delivery to the target lesion. We describe our initial experience with the use of this device for balloon remodeling to assist during aneurysm coil embolization. METHODS: All aneurysms that were treated with balloon remodeling employing the Scepter C balloon at a single institution (Medical University of South Carolina) from the time it was available in October 2011 to July 2012 were evaluated. Patient demographics, aneurysm characteristics, procedural success, and adverse events were assessed. RESULTS: 52 aneurysms were treated in 48 patients (45 women, three men) with a mean age of 59.3 ± 11 years (mean ± SD). Mean aneurysm height was 5.9 ± 3 mm, width 4.4 ± 2 mm with a 3.1 ± 2 mm broad neck. A variety of aneurysms were treated. The most commonly utilized size was the 4 mm × 10 mm (n=33) balloon. A Raymond 1 (complete occlusion) was achieved in the majority (n=44; 84.6%) of aneurysms, Raymond 2 (residual neck) in five, and Raymond 3 (residual aneurysm) in five. There was one complication (1.9%) attributed directly to balloon use. CONCLUSIONS: Our initial experience with the dual coaxial lumen Scepter C occlusion balloon catheter demonstrates its feasibility for use in balloon remodeling for aneurysm coil embolization. A variety of aneurysms at different locations were treated with satisfactory initial angiographic results and adverse event rates.

Expression of human proteins at the Southeast Collaboratory for Structural Genomics.

The human protein production group at the Southeast Collaboratory for Structural Genomics is charged with producing human proteins for both X-ray crystallography and NMR structural studies. Eukaryotic, and human proteins in particular, are notoriously difficult to express in bacterial systems. For various reasons, T7-based expression often results in protein expressed in an insoluble form. Overcoming this requires either introduction of a step to screen expression conditions or inclusion of a troublesome refolding step during purification. Our laboratory uses a trc-based expression vector that addresses many of the difficulties of the commonly used T7-based expression systems. Proteins expressed under the trc promoter, a weak promoter compared to the strong T7 promoter, are produced in a soluble form and include necessary cofactors. The details of this system will be discussed.