The effect of institutional case volume on post-operative outcomes after endarterectomy and stenting for symptomatic carotid stenosis.

OBJECTIVE: To investigate the effects of yearly institutional case volume for carotid endarterectomy (CEA) and stenting (CAS) among symptomatic carotid stenosis patients on the rates of postoperative stroke and inpatient mortality. MATERIALS AND METHODS: Patients with prior stroke ("symptomatic") undergoing CEA or CAS during an inpatient stay were identified from the National Inpatient Sample for years 2012-2015. The primary variable was volume of CEA or CAS performed annually by each institution. The primary outcome was a composite variable for in-hospital death or postoperative stroke. RESULTS: A total of 5,628 patients with symptomatic carotid stenosis underwent CEA, while 245 underwent CAS. In the symptomatic CEA population, 519 (9.2%) patients experienced postoperative stroke or mortality, and were more likely to be treated at centers with a lower yearly institutional volume (median 10 [IQR 5-15] versus 10 [7-20] cases, p<0.001). In the symptomatic CAS population, 32 (13.1%) patients experienced stroke or mortality, and these patients were also more likely to undergo treatment at hospitals with a lower yearly institutional volume (median 5 [IQR 5-7] versus 5 [5-10] cases, p=0.044). Thresholds for yearly institutional volume found differences in adverse outcome between 0-9, 10-29, and ≥30 cases/year (11.7% vs 8.4% vs 6.0%, p<0.001) for CEA, and differences in postoperative stroke between 0-9 and ≥10 cases/year for CAS (11.0% vs 1.4%, p=0.028). CONCLUSIONS: Hospitals performing higher volumes of CEA or CAS have fewer postoperative strokes. The threshold reported herein is ≥30 CEA procedures or ≥10 CAS procedures annually for appreciably improved outcomes.

Low diagnostic yield in follow-up MR imaging in patients with spontaneous intracerebral hemorrhage with a negative initial MRI.

PURPOSE: Follow-up MRI/MRA is historically obtained as outpatient when patients with a spontaneous intracerebral hemorrhage (ICH) have an initial MRI/MRA that is negative for an underlying structural lesion. However, the utility of repeating MR imaging in a delayed fashion remains uncertain. METHODS: We retrospectively reviewed 396 patients with spontaneous ICH admitted at our institution between 2015 and 2017 and selected those whose initial MRI/MRA was negative for an underlying structural lesion and those who underwent follow-up MR imaging in a delayed fashion. RESULTS: A total of 113 patients met the study criteria. The average age of those with negative follow-up MRI/MRA was 65.0 ± 12.6 (IQR: 55.0-74.0) years old. None of the 113 patients with a negative inpatient MRI/MRA had an underlying structural lesion on follow-up MRI/MRA (0%, 95% CI 0.0-0.032, p < 0.001). The mean time of the follow-up imaging from the initial study was 105.7 days (median: 62 days; IQR: 42.5-100.5). Of the 113, 83 (73.5%) underwent follow-up MRI with and without gadolinium, while 30 (26.5%) patients did not receive gadolinium. CONCLUSION: Delayed follow-up MRI in patients with a negative initial MRI/MRA for workup of spontaneous ICH was not diagnostic in any of the patients included in the study. Our study suggests that a routine follow-up MRI for this patient population is not necessary.

Adoption of the Transradial Approach for Neurointerventions: A National Survey of Current Practitioners.

OBJECTIVES: The transradial approach (TRA) is technically feasible for both diagnostic and therapeutic neurointerventions. It improves patient comfort and is not associated with increased procedural complications when compared to the transfemoral approach (TFA). To date, no studies have looked at barriers to adoption of TRA in the neurointerventionalist community. This study aims to obtain neurointerventionalist perspectives on their adoption of TRA. MATERIALS AND METHODS: Online survey distributed to neurointerventionalists. RESULTS: A total of 55 neurointerventionalists, 52 of whom utilized TRA, responded to our survey. Overall, participants were not concerned about TRA's technical feasibility for diagnostic or therapeutic neurointerventions or about procedural complications. Most of our cohort adopted TRA due to its increased patient comfort and to reduce access site complications. In-institution interventionalists were strongly perceived to be the most effective method of teaching TRA when compared to other methods. Catheters and equipment issues were reported by about 30% of our cohort as a barrier to TRA adoption. CONCLUSIONS: The neurointerventionalist community largely perceives TRA to be technically feasible and was not concerned about its procedural complications. In-person institutionalists are strongly perceived to be the most effective method of teaching the approach. A significant barrier to adoption seems to be related to catheters and equipment issues.

The impact of mechanical thrombectomy on the blood-brain barrier in patients with acute ischemic stroke: A non-contrast MR imaging study using DP-pCASL and NODDI.

BACKGROUND AND PURPOSE: While mechanical thrombectomy (MT) achieves restoration of cerebral blood flow to the area at risk in patients with acute ischemic stroke (AIS), the influx of blood flow may exacerbate the blood-brain barrier (BBB) disruption and extravasation across the BBB, and it therefore remains unclear how reperfusion impacts the blood-brain barrier integrity. In this study, we use diffusion-prepared pseudocontinuous ASL (DP-pCASL) and Neurite Orientation Dispersion and Density Imaging (NODDI) sequence to measure the water exchange rate (kw) in patients who underwent either MT or medical management and determine its impact on the brain tissue microstructure in order to elucidate the impact of MT on BBB complex integrity. MATERIALS AND METHODS: We prospectively enrolled 21 patients with AIS treated at our institution from 10/2021 to 6/2023 who underwent MR imaging at a 3.0-Tesla scanner. Patients underwent DP-pCASl and NODDI imaging in addition to the standard stroke protocol which generated cerebral blood flow (CBF), arterial transit time (ATT), water exchange rate (kw), orientation dispersion index (ODI), intracellular volume fraction (ICVF), and free water fraction (FWF) parametric maps. RESULTS: Of the 21 patients, 11 underwent MT and 10 were treated non-operatively. The average age and NIHSS for the MT cohort and non-MT cohorts were 69.3 ± 16.6 years old and 15.0 (12.0-20.0), and 70.2 ± 10.7 (p = 0.882) and 6.0 (3.8-9.0, p = 0.003) respectively. The average CBF, ATT, and kw in the infarcted territory of the MT cohort were 38.2 (18.4-59.6), 1347.6 (1182.5-1842.3), and 107.8 (79.2-140.1) respectively. The average CBF, ATT, and kw in the stroke ROI were 16.0 (8.8-36.6, p = 0.036), 1090.8 (937.1-1258.9, p = 0.013), 89.7 (68.0-122.7, p = 0.314) respectively. Linear regression analysis showed increasing CBF (p = 0.008) and undergoing mechanical thrombectomy (p = 0.048) were significant predictors of increased kw. CONCLUSION: Using our multimodal non-contrast MRI protocol, we demonstrate that increased CBF and mechanical thrombectomy increased kw, suggesting a better functioning BBB complex. Higher kw suggests less disruption of the BBB complex in the MT cohort.

Quantifying blood-brain barrier permeability in patients with ischemic stroke using non-contrast MRI.

Increased blood-brain barrier permeability (BBBP) after ischemic stroke predisposes patients to hemorrhagic conversion. While altered BBBP can impact patient recovery, it is not routinely assessed during the workup of acute ischemic stroke (AIS). We study the effectiveness of the non-contrast MRI sequences diffusion-prepared pseudocontinuous arterial spin labeling (DP-pCASL) and Neurite Orientation Dispersion and Density Imaging (NODDI) in assessing BBBP and correlating to tissue microstructure after ischemic insult. Twelve patients with AIS were prospectively enrolled to undergo our multimodal MR imaging, which generated the DP-pCASL-derived cerebral blood flow (CBF), arterial transit time (ATT), and water exchange rate (kw) and the NODDI-derived b0, mean diffusivity (MD), orientation dispersion index (ODI), intracellular volume fraction (ICVF), and isotropic volume fraction (ISO) parametric maps. The mean age of the patients was 70.2 ± 14.8 with an average NIHSS of 13.0 (7.3-19.8). MR imaging was performed on average at 53.7 (27.8-93.3) hours from stroke symptom onset. The water exchange rate (kw) of the infarcted area and its contralateral territory were 89.7 min-1 (66.7-121.9) and 89.9 min-1 (65.9-106.0) respectively (p = 0.887). Multivariable linear regression analysis showed that b0, ODI, ISO and mechanical thrombectomy were significant predictors of kw. DP-pCASL and NODDI are promising non-contrast sequences for the routine assessment of BBBP.

Experience With Ventriculoperitoneal and Lumboperitoneal Shunting for the Treatment of Idiopathic Intracranial Hypertension: A Single Institution Series.

BACKGROUND: CSF shunting is among the most widely utilized interventions in patients with idiopathic intracranial hypertension (IIH). Ventriculoperitoneal shunting (VPS) and lumboperitoneal shunting (LPS) are 2 possible treatment modalities. OBJECTIVE: To evaluate and compare complications, malfunction, infection, and revision rates associated with VPS compared to LPS. METHODS: Electronic medical records were reviewed to identify baseline and treatment characteristics for patients diagnosed with IIH treated with VPS or LPS. RESULTS: A total of 163 patients treated with either VPS (74.2%) or LPS (25.8%) were identified. The mean follow-up was 35 mo. Shunt revision was required in 40.9% of patients. There was a nonsignificant higher rate of revision with LPS (52.4%) than VPS (36.4%, P = .07). In multivariate analysis, increasing patient age was associated with higher odds of shunt revision (P = .04). LPS had higher odds of shunt revision, yet this association was not significant (P = .06). Shunt malfunction was the main indication for revision occurring in 32.7%, with a significantly higher rate with LPS than VPS (P = .03). In total, 15 patients had shunt infection (9.4% VPS vs 12.2% LPS P = .50). The only significant predictor of procedural infection was the increasing number of revisions (P = .02). CONCLUSION: The incidence of shunt revision was 40.9%, with increasing patient age as the sole predictor of shunt revision. The incidence of shunt malfunction was significantly higher in patients undergoing LPS, while there was no significant difference in the incidence of shunt infection between the 2 modalities.

Intra-arterial chemotherapy for retinoblastoma via the transradial route: Technique, feasibility, and case series.

OBJECTIVES: Intra-arterial chemotherapy (IAC) has become one of the most important pillars in retinoblastoma (Rb) management. It allows for targeted delivery of chemotherapy by superselective catheterization of the ophthalmic artery, thus, reducing systemic toxicity. As in most neurovascular procedures, IAC has traditionally been performed through a transfemoral access. However, recent publications have spurred the use of the transradial route for neuroendovascular procedures due to its lower complication rates and higher patient satisfaction. Here, we present the first case series in the literature on the technique, safety, and feasibility of IAC via the transradial route in the pediatric population. PATIENTS AND METHODS: We retrospectively analyzed our prospectively maintained database and present our technique and initial experience from 5 consecutive pediatric patients aged between 3 and 15 years who underwent 10 transradial IAC treatments. RESULTS: All IACs were performed successfully. Two patients had repeat IACs through the same wrist. There were no thromboembolic events or access site complications, such as hand ischemia or hematoma. All patients were discharged home the same day of the procedure. CONCLUSION: Our case series demonstrates the safety and feasibility of transradial IAC in pediatric patients with Rb. As more experience is gained with the transradial route for neurovascular procedures in adults, it may become the preferred route in some pediatric patients as well.

Initial Experience with Transradial Intraoperative Angiography in Aneurysm Clipping: Technique, Feasibility, and Case Series.

BACKGROUND: The transradial approach has slowly been gaining momentum in neuroendovascular procedures. We sought to assess its feasibility and safety and present a case series of transradial intraoperative angiography (IOA) during microsurgical clip ligation of intracranial aneurysms. METHODS: The setup and technique for transradial intraoperative angiography are described. Data on 10 consecutive patients undergoing IOA through the radial artery are presented. RESULTS: All target vessels were successfully catheterized transradially, and conversion to the transfemoral access was not required in any of the cases. There was no access-site complication, such as hand ischemia, hematoma, or radial artery spasm. There were also no thromboembolic events causing a stroke. The average time for the IOA was 9.3 minutes. CONCLUSIONS: Our initial experience shows the transradial approach for IOA in clip ligation of aneurysms to be feasible and safe, with potential advantages over transfemoral IOA.

Effect of Shunting on Visual Outcomes and Headache in Patients with Idiopathic Intracranial Hypertension.

BACKGROUND: Visual dysfunction and headache are major symptoms in patients with idiopathic intracranial hypertension (IIH). We aimed to evaluate the improvement of these symptoms in patients who underwent ventriculoperitoneal (VPS) and lumboperitoneal (LPS) shunting. METHODS: Electronic medical records were reviewed to identify baseline and treatment characteristics for patients diagnosed with IIH over 10 years. Visual outcomes and headache were evaluated at the latest follow-up post shunting. RESULTS: We included 163 patients with a mean age of 32.6 years. Most patients (74.2%) underwent VPS versus 25.8% of patients who received LPS. After a mean follow-up duration of 35 months, there was a 58.3% decrease in patients reporting headache (P = 0.006), an 87.7% decrease in papilledema (P = 0.1), a 100% resolution of diplopia with VPS or LPS, and an 88.5% decrease in transient visual obscurations (P = 1). In the worse eye, improved visual acuity (VA) occurred in 53.7% of eyes (P = 1), was stable in 16.4%, and worsened in 29.8%. The mean LogMAR VA was improved by 0.06 LogMAR (20/68) in the worse eye (P = 0.97) and 0.08 LogMAR (20/31) in the better eye (P = 0.7). The visual function that impairs daily activity was decreased by 55.4% (P = 0.08). Patients shunted within 1 month of presentation had a significantly higher rate of headache (P = 0.04) and VA improvement (P < 0.001). CONCLUSIONS: VPS and LPS are effective in improving visual symptoms and headache in patients with IIH.

Bilateral Mechanical Thrombectomies for Simultaneous MCA Occlusions.

BACKGROUND: Bilateral hemispheric dysfunction is devastating to consciousness. We present a unique case of a patient who developed bilateral middle cerebral artery infarcts with significant neurological improvement post bilateral thrombolysis in cerebral infarction (TICI) 3 thrombectomies. CASE DESCRIPTION: The patient is a 64-year-old woman who presented 3 hours after her husband was awakened and found her with left hemiplegia. She had a history of atrial fibrillation and had her apixaban held for 5 days before the coronary angiogram that she received the day before arrival. Upon presentation, she was antigravity on the right side and withdrawing on the left side. Computed tomography angiogram showed a right M1 occlusion and an left M2 occlusion. Computed tomography perfusion revealed a mismatch with large penumbra, and she was taken for mechanical thrombectomy. Mechanical thrombectomy was performed using a combination of stent retriever and aspiration catheter with a TICI 3 revascularization. By the following morning, the patient was full strength on the right and antigravity on the left with a left facial droop. The patient recovered her speech and was fully oriented before leaving for rehabilitation on postoperative day 3. CONCLUSIONS: The transient hypercoagulable state that was created with the withdrawal of apixaban likely increased our patient's risk of stroke. The literature supports continuing oral anticoagulants for endovascular procedures. The devastating consequences of thromboembolic events, whether stroke or pulmonary embolism, can be catastrophic, but luckily, mechanical thrombectomy provides the means to minimize the morbidity and mortality from bilateral infarctions.

Transradial Access for Newly Food and Drug Administration-Approved Devices for Endovascular Treatment of Cerebral Aneurysms: A Technical Note.

BACKGROUND: Despite the recent increase of transradial access among neurointerventionalists, there is still a paucity of evidence in the neurosurgical literature. There are 3 newly Food and Drug Administration-approved devices-Woven EndoBridge (WEB), Surpass, and PulseRider-that significantly expand the options available for endovascular treatment of cerebral aneurysms. Our work reports the safety and feasibility of radial artery catheterization for the deployment of these new devices. METHODS: We performed a review of the first 10 patients with an unruptured cerebral aneurysm treated via a transradial cerebral angiogram. Seven patients underwent embolization with the WEB device, 1 patient underwent embolization with the PulseRider, and 2 patients underwent embolization with the Surpass device. We describe in detail our workflow and the devices used for transradial access. RESULTS: The aneurysms treated include internal carotid artery bifurcation, middle cerebral artery, anterior communicating artery, basilar tip, and posterior communicating artery. All patients underwent radial artery catheterization, and none of them had to be converted to femoral artery access. Of the 10 patients, 9 required a single attempt for accurate device deployment. One patient had unsuccessful placement of the WEB device and required coiling of the aneurysm because of device herniation into the parent vessel. None of the patients had any postoperative complications and were discharged the following day with the same modified Rankin scale score as preoperatively. CONCLUSIONS: Our experience with 10 patients revealed no limitations during catheterization and deployment of these devices. One patient had to be converted to coil embolization, which was feasible through the same vascular access. None of the patients had vascular complications postoperatively with minimal wrist discomfort.