Direct Versus Indirect Revascularization for Moyamoya: a Large Multicenter Study.

BACKGROUND: Moyamoya is a chronic occlusive cerebrovascular disease of unknown etiology causing neovascularization of the lenticulostriate collaterals at the base of the brain. Although revascularization surgery is the most effective treatment for moyamoya, there is still no consensus on the best surgical treatment modality as different studies provide different outcomes. OBJECTIVE: In this large case series, we compare the outcomes of direct (DR) and indirect revascularisation (IR) and compare our results to the literature in order to reflect on the best revascularization modality for moyamoya. METHODS: We conducted a multicenter retrospective study in accordance with the Strengthening the Reporting of Observational studies in Epidemiology guidelines of moyamoya affected hemispheres treated with DR and IR surgeries across 13 academic institutions predominantly in North America. All patients who underwent surgical revascularization of their moyamoya-affected hemispheres were included in the study. The primary outcome of the study was the rate of symptomatic strokes. RESULTS: The rates of symptomatic strokes across 515 disease-affected hemispheres were comparable between the two cohorts (11.6% in the DR cohort vs 9.6% in the IR cohort, OR 1.238 (95% CI 0.651 to 2.354), p=0.514). The rate of total perioperative strokes was slightly higher in the DR cohort (6.1% for DR vs 2.0% for IR, OR 3.129 (95% CI 0.991 to 9.875), p=0.052). The rate of total follow-up strokes was slightly higher in the IR cohort (8.1% vs 6.6%, OR 0.799 (95% CI 0.374 to 1.709) p=0.563). CONCLUSION: Since both modalities showed comparable rates of overall total strokes, both modalities of revascularization can be performed depending on the patient's risk assessment.

Comparison of PED/PED Flex and PED Shield in the treatment of unruptured intracerebral aneurysms.

OBJECTIVE: The object of this study was to compare the efficacy and safety profile of the Pipeline embolization device (PED)/Pipeline Flex embolization device (PED Flex) with that of the Pipeline Flex embolization device with Shield Technology (PED Shield). After introducing the first-generation PED and the second-generation PED Flex with its updated delivery system, the PED Shield was launched with a synthetic layer of phosphorylcholine surface modification to reduce thrombogenicity. METHODS: This is a retrospective review of unruptured aneurysms treated with PED/PED Flex versus PED Shield between 2017 and 2022 at the authors' institution. Patients with ruptured aneurysms, adjunctive treatment, failed flow diverter deployment, and prior treatment of the target aneurysm were excluded. Baseline characteristics were collected for all patients, including age, sex, past medical history (hypertension, hyperlipidemia, diabetes mellitus), smoking status, aneurysm location, and aneurysm dimensions (neck, width, height) and morphology (saccular, nonsaccular). The primary outcome was procedural and periprocedural complication rates. RESULTS: The study cohort comprised 200 patients with 200 aneurysms, including 150 aneurysms treated with the PED/PED Flex and 50 treated with the PED Shield. With respect to intraprocedural and periprocedural complications, length of stay, length of follow-up, and functional outcome at discharge, there was no significant difference between the two cohorts. At the midterm follow-up, the rate of in-stent stenosis (PED/PED Flex: 14.2% vs PED Shield: 14.6%, p = 0.927), aneurysm occlusion (complete occlusion: 79.5% vs 80.5%, respectively; neck remnant: 4.7% vs 12.2%; dome remnant: 15.7% vs 7.3%; p = 0.119), and the need for retreatment (5.3% vs 0%, p = 0.097) were comparable between the two cohorts. CONCLUSIONS: This study suggests that, as compared to first- and second-generation PED and PED Flex, the third-generation PED Shield offers similar rates of complications, aneurysm occlusion, and in-stent stenosis at the midterm follow-up.

Post-operative weight loss in venous sinus stenting patients: A multi-center review, systematic review, and meta-analysis.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) can result in headaches, pulsatile tinnitus, papilledema, and other neurological symptoms. Weight loss can alleviate some symptoms of IIH. This study aims to investigate the effect of venous sinus stenting on post-operative weight and body mass index (BMI) changes among IIH patients. The secondary objective is to investigate the relationship between post-operative weight changes and papilledema resolution. METHODS: Patients with papilledema undergoing venous sinus stenting for IIH were retrospectively reviewed from two comprehensive North American cerebrovascular centers. Patient demographics, surgical course, post-operative outcomes, and weight were analyzed. A systematic review and meta-analysis of post-operative weight in stented IIH patients was conducted. RESULTS: Twenty-eight patients with a diagnosis of IIH and papilledema who underwent venous sinus stenting were identified across two institutions. Patients had a mean pre-operative weight of 103.2 kg, which decreased to 101.5 kg at 3-month follow up (p = 0.0757). Patients at 6-month follow-up saw a weight decrease to 97.4 kg (p = 0.0066). Patients who saw papilledema resolution saw a mean greater decrease in weight (-4.5%) at 6-month follow up than those whose papilledema did not resolve (-1.7%), although this was insignificant (p = 0.1091). A total of 41 patients were included in the meta-analysis. Patients had an average of 1.1 increase in BMI at 3-month follow up. CONCLUSIONS: This study shows that venous sinus stenting leads to modest weight reduction in IIH patients, and those with resolved papilledema experience slightly greater weight loss. Further research is necessary to determine the clinical significance of these findings.

Frameless Angiography-Based Gamma Knife Stereotactic Radiosurgery for Cerebral Arteriovenous Malformations: A Proof-of-Concept Study.

BACKGROUND: Traditional Gamma Knife radiosurgery (GKRS) of brain arteriovenous malformations (AVMs) using digital subtraction angiography (DSA) requires head immobilization using a stereotactic frame. OBJECTIVE: We describe our protocol of frameless GKRS using DSA while maintaining high spatial resolution for precision. METHODS: This study is a retrospective review of patients with unruptured AVMs who underwent frameless GKRS. Magnetic resonance imaging and 3-dimensional DSA were obtained without a stereotactic frame for all patients. The imaging studies were merged for contouring of the AVM nidus. During GKRS treatment, patients were immobilized using an individually molded thermoplastic mask. RESULTS: Thirty-one patients were included in the analysis. The median age is 45.0 years (interquartile range [IQR]: 28.0-55.0). The median nidus size is 3.0 cm (IQR: 2.0-3.4). One patient had a Spetzler-Martin grade I, 11 had a grade II, 11 had a grade III, 6 had a grade IV, and 2 had a grade V AVM. Eleven patients underwent preradiosurgical embolization, 3 patients had previous microsurgical resection and/or embolization, and 1 patient had prior radiosurgery. The median administered dose was 20 Gy (IQR: 18.0-21.0). All patients completed their treatment with the planned radiation dose without complications. CONCLUSION: This is the first study that integrates DSA in the treatment planning of brain AVMs using GKRS without utilizing a stereotactic head frame. Frameless GKRS provides numerous advantages over frame-based techniques including improved patient experience and the capability of fractionation and thus expanding the eligibility of more AVMs for radiosurgery, while maintaining high spatial resolution of the AVM using angiography data.

Woven EndoBridge versus stent-assisted coil embolization of cerebral bifurcation aneurysms.

OBJECTIVE: Stent-assisted coil (SAC) embolization has been the mainstay endovascular treatment for bifurcation aneurysms. The recent introduction of the Woven EndoBridge (WEB) device has presented an alternative endovascular treatment modality for these aneurysms. Direct comparisons of outcomes between these two modalities are limited in the literature. Here, the authors compared the outcomes of bifurcation aneurysms treated with SAC and WEB devices. METHODS: This retrospective single-center study comprised 148 bifurcation aneurysms that were treated endovascularly with SAC or WEB devices between 2011 and 2019. The primary outcome was complete occlusion of the aneurysm at 6 months on catheter angiography. RESULTS: The SAC and WEB cohorts comprised 85 and 63 aneurysms, respectively. The baseline characteristics were well balanced after inverse probability weight (IPW) adjustment, except for smoking status. The 6-month complete occlusion rate was higher in the WEB cohort than the SAC cohort (67.4% vs 40.6%; unadjusted OR [95% CI] 3.014 [1.385-6.563], p = 0.005). However, this difference in complete occlusion rates did not remain significant after IPW adjustment and multiple imputations. The neck remnant rate was lower in the WEB cohort than the SAC cohort (20% vs 50%; OR [95% CI] 0.250 [0.107-0.584], p = 0.001), and this difference remained significant after IPW adjustment (OR [95% CI] 0.304 [0.116-0.795], p = 0.015) and multiple imputations. CONCLUSIONS: Use of SAC and WEB demonstrated comparable 6-month complete occlusion rates for bifurcation aneurysms. WEB appeared to be associated with a lower rate of neck remnant at 6 and 12 months compared with SAC. WEB was also associated with fewer complications and decreased retreatment rates compared with SAC.

Endovascular Robotic Interventions.

After robotic systems were approved for peripheral vascular interventions, many centers adopted this technology in treating carotid diseases. Robotic systems provide several advantages by eliminating radiation exposure and decreasing the rate of musculoskeletal injuries among interventionalists. The main disadvantage this technology poses is the lack of haptic feedback. Based on the experience of our center and several others, robotic systems have proved to be efficient, feasible, and safe when treating carotid diseases. One of the main goals of robotic systems is their future potential in remotely treating stroke patients living in rural geographic areas.

Robot-assisted carotid artery stenting: outcomes, safety, and operational learning curve.

OBJECTIVE: Over the past 2 decades, robots have been increasingly used in surgeries to help overcome human limitations and perform precise and accurate tasks. Endovascular robots were pioneered in interventional cardiology, however, the CorPath GRX was recently approved by the FDA for peripheral vascular and extracranial interventions. The authors aimed to evaluate the operational learning curve for robot-assisted carotid artery stenting over a period of 19 months at a single institution. METHODS: A retrospective analysis of a prospectively maintained database was conducted, and 14 consecutive patients who underwent robot-assisted carotid artery stenting from December 2019 to June 2021 were identified. The metrics for proficiency were the total fluoroscopy and procedure times, contrast volume used, and radiation dose. To evaluate operator progress, the patients were divided into 3 groups of 5, 4, and 5 patients based on the study period. RESULTS: A total of 14 patients were included. All patients received balloon angioplasty and stent placement. The median degree of stenosis was 95%. Ten patients (71%) were treated via the transradial approach and 4 patients (29%) via the transfemoral approach, with no procedural complications. The median contrast volume used was 80 mL, and the median radiation dose was 38,978.5 mGy/cm2. The overall median fluoroscopy and procedure times were 24.6 minutes and 70.5 minutes, respectively. Subgroup analysis showed a significant decrease in these times, from 32 minutes and 86 minutes, respectively, in group 1 to 21.9 minutes and 62 minutes, respectively, in group 3 (p = 0.002 and p = 0.008, respectively). CONCLUSIONS: Robot-assisted carotid artery stenting was found to be safe and effective, and the learning curve for robotic procedures was overcome within a short period of time at a high-volume cerebrovascular center.

Preoperative Ultrasound-Guided Percutaneous Embolization of Orbital Lymphaticovenous Malformations Using Onyx.

The treatment of orbital lymphaticovenous malformations (OLVMs) has evolved from simple surgical resection to a multimodal approach consisting of sclerosing agents, embolization, and resection depending on the specific components that compose the lesion. Here we present a representative case series of 5 nonconsecutive patients who underwent percutaneous embolization of OLVMs with the Onyx Liquid Embolic System (Medtronic, Dublin, Ireland) before surgical resection between 2019 and 2021. OLVMs are rare, benign, congenital lesions that grow with age and can become symptomatic and disabling. Treatment can be conservative or invasive; depending on the clinical presentation and characteristics of the lesions, treatment modalities can vary. Preoperative percutaneous embolization of OLVMs with the Onyx system is a promising technique, as demonstrated in this case series.

Carotid Blowout Management in the Endovascular Era.

BACKGROUND: Carotid blowout syndrome (CBS) is a potential complication of head and neck cancer, and its therapy is associated with high morbidity and mortality. Recent advances in endovascular techniques have improved patient outcomes. In this study, we report outcomes of emergent endovascular intervention for CBS. METHODS: We conducted a retrospective analysis of a prospectively maintained neurovascular database and identified 38 consecutive endovascular procedures for CBS from 2008-2019 at our institution. Data collection was performed on patient demographics, type of cancer, previous cancer treatments, type of CBS, location of bleed, diagnostic workup, endovascular treatment, and procedural outcomes and complications. RESULTS: A total of 38 consecutive endovascular procedures for CBS were performed from 2008-2019 at our single academic institution. Technical success was achieved in 100% of endovascular procedures. Procedural stroke occurred in 1 (2.6%) procedure, procedural mortality occurred in 1 (2.6%) procedure, recurrent CBS occurred in 4 (10.5%) procedures, and fatal rehemorrhage occurred in 1 (2.6%) procedure. Regarding secondary outcomes, delayed stroke/transient ischemic attack occurred in 1 (2.6%) procedure, whereas there were no cases of delayed infectious complications. CONCLUSIONS: The endovascular treatment of CBS is safe and effective with relatively low rates of morbidity and mortality compared with other currently available treatment modalities. However, the overall rate of complications demands attention and sheds light on the need for further improvement in management.

Predictors of ventriculostomy infection in a large single-center cohort.

OBJECTIVE: External ventricular drain (EVD) placement is a common neurosurgical procedure. While this procedure is simple and effective, infection is a major limiting factor. Factors predictive of infection reported in the literature are not conclusive. The aim of this retrospective, single-center large series was to assess the rate and independent predictors of ventriculostomy-associated infection (VAI). METHODS: The authors performed a retrospective chart review of consecutive patients who underwent EVD placement between January 2012 and January 2018. RESULTS: A total of 389 patients were included in the study. The infection rate was 3.1% (n = 12). Variables that were significantly associated with VAI were EVD replacement (OR 10, p = 0.001), bilateral EVDs (OR 9.2, p = 0.009), duration of EVD placement (OR 1.1, p = 0.011), increased CSF output/day (OR 1.0, p = 0.001), CSF leak (OR 12.9, p = 0.001), and increased length of hospital stay (OR 1.1, p = 0.002). Using multivariate logistic regression, independent predictors of VAI were female sex (OR 7.1, 95% CI 1.1-47.4; p = 0.043), EVD replacement (OR 8.5, 95% CI 1.44-50.72; p = 0.027), increased CSF output/day (OR 1.01, 95% CI 1.0-1.02; p = 0.023), and CSF leak (OR 15.1, 95% CI 2.6-87.1; p = 0.003). CONCLUSIONS: The rate of VAI was 3.1%. Routine CSF collection (every other day or every 3 days) and CSF collection when needed were not associated with VAI. The authors recommend CSF collection when clinically needed rather than routinely.

Endovascular robotic: feasibility and proof of principle for diagnostic cerebral angiography and carotid artery stenting.

BACKGROUND: Robots in surgery aid in performing delicate, precise maneuvers that humans, with inherent physical abilities, may be limited to perform. The CorPath 200 system is FDA approved and is being implemented in the US for interventional cardiology procedures. CorPath GRX robotic-assisted platform is the next-generation successor of CorPath 200. OBJECTIVE: To discuss the feasibility and early experience with the use of the CorPath GRX robotic-assisted platform for neuroendovascular procedures, including transradial diagnostic cerebral angiograms and transradial carotid artery stenting. METHODS: The cases of 10 consecutive patients who underwent neuroendovascular robotic-assisted procedures between December 1, 2019 and December 30, 2019, are presented. RESULTS: Seven patients underwent elective diagnostic cerebral angiography, and three patients underwent carotid artery angioplasty and stenting using the CorPath GRX robotic-assisted platform. All procedures were performed successfully, and no complications were encountered. Conversion to manual control occurred in three diagnostic cases because of a bovine arch that was previously not known. The fluoroscopy time and the procedure time continued to improve with subsequent procedures as we streamlined the workflow. CONCLUSION: This series demonstrates the early use of this technology. It could potentially be used in the near future for acute stroke interventions in remote geographic locations and in places where a neurointerventionalist is not available.