Towards MR-Guided Robotic Intracerebral Hemorrhage Evacuation: Aiming Device Design and ex vivo Ovine Head Trial.

Stereotactic neurosurgery is a well-established surgical technique for navigation and guidance during treatment of intracranial pathologies. Intracerebral hemorrhage (ICH) is an example of various neurosurgical conditions that can benefit from stereotactic neurosurgery. As a part of our ongoing work toward real-time MR-guided ICH evacuation, we aim to address an unmet clinical need for a skull-mounted frameless stereotactic aiming device that can be used with minimally invasive robotic systems for MR-guided interventions. In this paper, we present NICE-Aiming, a Neurosurgical, Interventional, Configurable device for Effective-Aiming in MR-guided robotic neurosurgical interventions. A kinematic model was developed and the system was used with a concentric tube robot (CTR) for ICH evacuation in (i) a skull phantom and (ii) in the first ever reported ex vivo CTR ICH evacuation using an ex vivo ovine head. The NICE-Aiming prototype provided a tip accuracy of 1.41±0.35 mm in free-space. In the MR-guided gel phantom experiment, the targeting accuracy was 2.07±0.42 mm and the residual hematoma volume was 12.87 mL (24.32% of the original volume). In the MR-guided ex vivo ovine head experiment, the targeting accuracy was 2.48±0.48 mm and the residual hematoma volume was 1.42 mL (25.08% of the original volume).

Optimal Concentric Tube Robot Design for Safe Intracerebral Hemorrhage Removal.

Purpose: The purpose of this paper is to investigate the geometrical design and path planning of Concentric tube robots (CTR) for intracerebral hemorrhage (ICH) evacuation, with a focus on minimizing the risk of damaging white matter tracts and cerebral arteries. Methods: To achieve our objective, we propose a parametrization method describing a general class of CTR geometric designs. We present mathematical models that describe the CTR design constraints and provide the calculation of a path risk value. We then use a genetic algorithm to determine the optimal tube geometry for targeting within the brain. Results: Our results show that a multi-tube CTR design can significantly reduce the risk of damaging critical brain structures compared to the conventional straight tube design. However, there is no significant relationship between the path risk value and the number and shape of the additional inner curved tubes. Conclusion: Considering the challenges of CTR hardware design, fabrication, and control, we conclude that the most practical geometry for a CTR path in ICH treatment is a straight outer tube followed by a planar curved inner tube. These findings have important implications for the development of safe and effective CTRs for ICH evacuation by enabling dexterous manipulation to minimize damage to critical brain structures.

Visual Morbidity in Patients With Ophthalmic Segment Aneurysms Treated With Flow Diverters: A Dual-Center Experience.

BACKGROUND AND OBJECTIVE: Flow diverter (FD) treatment for aneurysms of the ophthalmic segment of the internal carotid artery (ICA) may raise concerns about visual morbidity related to coverage of the ophthalmic artery by the device. Our objective was to evaluate clinical and angiographic outcomes associated with FD treatment of these aneurysms, with particular emphasis on visual morbidity. METHODS: We performed a retrospective analysis of the endovascular databases at 2 US centers to identify consecutive patients with aneurysms along the ophthalmic segment of the ICA that were treated with FDs between January 2010 and December 2022. Baseline demographics, aneurysm characteristics, and periprocedural and postprocedural data, including the occurrence of visual complications, were collected. RESULTS: One hundred and thirteen patients with 113 aneurysms were identified for inclusion in this study. The mean age of the patients was 59.5 ± 12.4 years, and 103 (91.2%) were women. The ophthalmic artery origin was involved in 40 (35.4%) aneurysms, consisting of a neck origin in 33 (29.2%) and a dome origin in 7 (6.2%). New transient visual morbidity during the hospital stay included impaired visual acuity or blurriness in 1 (0.9%) patient, diplopia in 1 (0.9%), and floaters in 1 (0.9%). New transient visual morbidity during follow-up included impaired visual acuity or blurriness in 5 patients (4.4%), diplopia in 3 (2.7%), ipsilateral visual field defect in 1 (0.9%), and floaters in 6 (5.3%). Permanent visual morbidity occurred in 1 patient (0.9%). Among the 101 patients who had angiographic follow-up, the Raymond-Roy occlusion classifications were I (complete aneurysm occlusion) in 85 (84.2%), II (residual neck) in 11 (10.9%), and III (residual aneurysm) in 5 (4.9%). CONCLUSION: In our experience, flow diversion for ICA ophthalmic segment aneurysms resulted in low rates of visual morbidity, which was mostly transient in occurrence.

Survey of United States neurosurgeons on firearm injury prevention.

OBJECTIVE: Firearm-related injuries and deaths are an endemic problem in the US, posing a burden on the healthcare system with significant social and economic consequences. As front-line care providers for these patients, neurosurgeons are both knowledgeable about these injuries and credible messengers in the public discussion of ways to reduce firearm injuries. The purpose of this study was to explore US-based neurosurgeons' views and behaviors regarding firearms to understand and define a potential role for neurosurgical organizations in advocacy efforts to reduce firearm death and injuries. METHODS: The authors conducted an anonymous survey of US neurosurgeons using the American Association of Neurological Surgeons (AANS) member database from April to June 2023. The 22-question survey included questions related to firearm ownership, personal views on firearms, and support for both general and policy-specific advocacy efforts to reduce firearm deaths and injuries. RESULTS: The survey response rate was 20.7%, with 1568 of the 7587 members invited completing the survey. The survey completion rate was 93.4%, with 1465 of the 1568 surveys completed and included in this analysis. The majority of respondents were male (raw: 81.7%; weighted 81.1%), White (raw: 69.7%; weighted 70.2%), and older than 50 years (raw: 56.2%; weighted: 54%). Most respondents reported treating patients with firearm injuries (raw: 83.3%; weighted: 82%), 85.5% (weighted: 85.1%) had used a firearm, and 42.4% (weighted: 41.5%) reported owning a firearm. Overall, 78.8% (weighted: 78.7%) of respondents felt that organized neurosurgery should participate in advocacy efforts. When examining individual policies, those that restrict the acquisition of firearms garnered the support of at least 65% of respondents, while nonrestrictive policies were supported by more than 75% of respondents. Free-text responses provided insight into both motivations for and objections to organizational advocacy. CONCLUSIONS: The majority of US-based neurosurgeons support involvement in advocacy efforts to reduce firearm deaths and injuries. Themes expressed by members both supporting and objecting to advocacy provide insight into approaches that could ensure broad support. Neurosurgical organizations such as the AANS and Congress of Neurological Surgeons may use the results of this survey to make informed decisions regarding involvement in advocacy efforts on behalf of their membership to lessen the burden of firearm injury in the US.

Non-Metallic MR-Guided Concentric Tube Robot for Intracerebral Hemorrhage Evacuation.

OBJECTIVE: We aim to develop and evaluate an MR-conditional concentric tube robot for intracerebral hemorrhage (ICH) evacuation. METHODS: We fabricated the concentric tube robot hardware with plastic tubes and customized pneumatic motors. The robot kinematic model was developed using a discretized piece-wise constant curvature (D-PCC) approach to account for variable curvature along the tube shape, and tube mechanics model was used to compensate torsional deflection of the inner tube. The MR-safe pneumatic motors were controlled using a variable gain PID algorithm. The robot hardware was validated in a series of bench-top and MRI experiments, and the robot's evacuation efficacy was tested in MR-guided phantom trials. RESULTS: The pneumatic motor was able to achieve a rotational accuracy of 0.32°±0.30° with the proposed variable gain PID control algorithm. The kinematic model provided a positional accuracy of the tube tip of 1.39 ± 0.54 mm. The robot was able to evacuate an initial 38.36 mL clot, leaving a residual hematoma of 8.14 mL after 5 minutes, well below the 15 mL guideline suggesting good post-ICH evacuation clinical outcomes. CONCLUSION: This robotic platform provides an effective method for MR-guided ICH evacuation. SIGNIFICANCE: ICH evacuation is feasible under MRI guidance using a plastic concentric tube, indicating potential feasibility in future live animal studies.

Feasibility and Safety of Transradial Aneurysm Embolization: A Systematic Review and Meta-Analysis.

OBJECTIVE: Use of the transradial access (TRA) approach for neuroendovascular procedures has been increasing in recent years. Our aim is to assess the feasibility, success rate, and complications associated with TRA for intracranial aneurysm embolization. METHODS: PubMed, Scopus, and Embase were systematically searched for studies using TRA for intracranial aneurysm embolization. Random-effects models were used to obtain pooled rates of procedural success and complications. RESULTS: Twenty-four studies comprising 1283 (85.9%) TRA and 122 (8.2%) distal TRA aneurysm embolization procedures were included. The pooled success rate of the 18 studies in the meta-analysis was 93.5% (95% confidence interval [CI], 91.1%-95.8%). The pooled thromboembolic complication rate was 0.5% (95% CI, 0.1%-0.9%), the hemorrhagic complication rate was 0.5% (95% CI, 0.1%-0.9%), and the access site complication rate was 0.8% (95% CI, 0.3%-1.3%). One study (4.3%) used exclusively a 7-French guide catheter, and most used a 6-French guide catheter (22 of 23 studies, 95.7%), which was further incorporated as part of a triaxial configuration through a sheathless 8-French system in 4 studies (17.4%), 7-French guide catheter in 2 studies (8.7%), and 8-French sheath in 1 study (4.3%). The embolization techniques used were flow diverter placement in 451 cases (39.1%), coiling in 376 (32.6%), stent-assisted coiling in 127 (11.0%), balloon-assisted coiling in 104 (9.0%), Woven EndoBridge system in 50 (4.3%), and flow diverter placement plus coiling in 42 (3.6%). CONCLUSIONS: Treating intracranial aneurysms using various embolization techniques through TRA is feasible and associated with low access site and intraoperative complications.

Minimally Invasive Intracerebral Hemorrhage Evacuation: A review.

Intracerebral hemorrhage is a leading cause of morbidity and mortality worldwide. To date, there is no specific treatment that clearly provides a benefit in functional outcome or mortality. Surgical treatment for hematoma evacuation has not yet shown clear benefit over medical management despite promising preclinical studies. Minimally invasive treatment options for hematoma evacuation are under investigation but remain in early-stage clinical trials. Robotics has the potential to improve treatment. In this paper, we review intracerebral hemorrhage pathology, currently available treatments, and potential robotic approaches to date. We also discuss the future role of robotics in stroke treatment.

Impact of Direct Admission Versus Interfacility Transfer on Endovascular Treatment Outcomes for Acute Ischemic Stroke: Systematic Review and Meta-Analysis.

BACKGROUND: Mechanical thrombectomy is a proven treatment for large-vessel ischemic stroke with improved functional outcomes compared with intravenous thrombolytics. Access to thrombectomy-capable sites varies greatly by geography, often necessitating interhospital transfer of patients who first present to hospitals unable to provide thrombectomy. The purpose of this meta-analysis was to examine the impact of interhospital transportation on patient outcomes to better inform recommendations for prehospital protocols. METHODS: A meta-analysis was performed following systematic literature searches. Outcomes of interest included successful reperfusion, symptomatic intracranial hemorrhage, 90-day modified Rankin Scale score 0-2, 90-day mortality, onset-to-puncture times, and door-to-puncture times. RESULTS: Pooled analysis comprised >27,000 patients. Door-to-puncture time was 35.6 minutes shorter among transferred patients; however, symptom onset-to-puncture time was 91.6 minutes longer. Rate of reperfusion or symptomatic intracranial hemorrhage as well as 90-day mortality did not differ significantly between transferred and directly admitted patients. While the proportion of patients achieving good functional outcome at 90 days with modified Rankin Scale score 0-2 did not differ by admission type, when modified Rankin Scale score was narrowed to 0-1, direct transport showed 20% greater probability of achieving excellent functional outcome (P < 0.001). CONCLUSIONS: This meta-analysis represents the largest pooled population examined to date to assess how interfacility transportation to thrombectomy-capable sites affects patient outcomes. Our results indicate that direct admission is a significant predictor of excellent functional outcome. The findings presented here can be used to better inform quality improvement projects to streamline access to facilities providing endovascular mechanical thrombectomy capabilities.

Trends in Endovascular Mechanical Thrombectomy in Treatment of Acute Ischemic Stroke in the United States.

BACKGROUND: Numerous randomized controlled trials have shown that endovascular mechanical thrombectomy (MT) is an effective treatment for large vessel ischemic stroke. This study examines variation in rates of MT across the United States by geographic region and urban-rural areas to identify utilization disparities. METHODS: Data from the Global Burden of Disease Collaborative Network were used to determine acute ischemic stroke (AIS) incidence by state for 2016. The 2016 National Inpatient Sample was accessed to identify patients who underwent MT and patients who were diagnosed with cerebral infarct due to thrombosis or embolism of anterior circulation arteries representing the AIS population of interest. National Inpatient Sample data were used to create national weighted estimates of the size of subject populations, age at admission, length of stay, and discharge status. RESULTS: In the United States, approximately 13,010 mechanical thrombectomies were performed in 2016, representing 3.1% of the AIS population. Proportions of patients undergoing MT were highest in large central metropolitan areas and lowest in rural settings when compared with the national estimate. East North Central and West South Central regions had significantly lower proportions of patients treated with MT. Discharge destinations, a proxy for clinical outcome, differed significantly by region and urban-rural designation. CONCLUSIONS: The number of MTs performed in 2016 increased approximately 1.3 times from 2015. Considering that 10%-17% of patients with AIS may be MT-eligible, current rates of MT are low across all regions, but the most pronounced disparities and poorer clinical outcomes occur in rural areas, particularly in the Northeast/Southwest regions of the Midwest.

Fixed Dose IV rt-PA and Clinical Outcome in Ischemic Stroke Patients With Body Weight >100 kg: Pooled Data From 3 Randomized Clinical Trials.

BACKGROUND AND PURPOSE: The ASA/AHA guidelines recommend a fixed dose of 90 mg of intravenous (IV) recombinant tissue plasminogen activator (rt-PA) for acute stroke patients weighing more than 100 kg. We aimed to determine if body weight >100 kg (and receiving <0.9 mg/kg dose) independently influence patient clinical outcomes following IV rt-PA treatment. METHODS: We pooled data from IV rt-PA treatment arms from 3 randomized controlled clinical trials; NINDS IV rt-PA study, Interventional Management of Stroke 3 and ALIAS (part 1 and 2). Baseline characteristic, hospital course and 90-day mRS were compared between patients >100 kg and those ≤100 kg body weight. Multivariate logistic regression model was used to identify the independent effect of >100 kg body weight on favorable 90-day outcome (defined as mRS 0-2), the rate of symptomatic intracranial hemorrhage, and poor 90-day outcome (mRS 4-6). RESULTS: Among 873 patients treated with IV rt-PA, a total of 105 (12%) subjects had body weight >100 kg. Compared with patients having ≤100 kg body weight, the rate of favorable outcome at 90 days was not significantly different among patients with >100 kg body weight (OR: 0.99; 95% CI: 0.91-1.01; p=0.91) , after adjusting for potential confounders. The ordinal analysis did not show any significant shift in the distribution of 90-day mRS score in patients with >100 kg body weight (OR, 0.93; 95% CI, 0.64-1.37; P = 0.74) CONCLUSIONS: There was no reduction in the rate of favorable outcome in patients with acute ischemic stroke with body weight >100 kg who received <0.9 mg/kg dose of IV rt-PA. Our results support the current recommendations in the ASA/AHA guidelines.

Early Outcomes after Carotid Endarterectomy and Carotid Artery Stenting for Carotid Stenosis in the ACS-NSQIP Database.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are both viable treatment options for carotid artery stenosis. We sought to compare perioperative outcomes after CEA and CAS for the management of carotid stenosis using a "real-world" sample. METHODS: We conducted a retrospective observational study using the National Surgical Quality Improvement Program database to compare 30-day (periprocedural) outcomes in patients with carotid stenosis undergoing CEA versus CAS from 2005 to 2012. Baseline characteristics and periprocedural outcomes including stroke, myocardial infarction, mortality and combined outcome (composite of any stroke, myocardial infarction, or death) were compared. RESULTS: A total of 54,640 patients were identified who underwent CEA and 488 who underwent CAS. Patients undergoing CEA were more likely to be older and have symptomatic stenosis, and less likely to be white, have congestive heart failure, and have chronic obstructive pulmonary disease. There were no significant differences between CEA and CAS in periprocedural mortality (0.9% vs. 1.2%, p = 0.33), stroke (1.6% vs. 1.6 p = 0.93), myocardial infarction (0.9% vs. 1.6%, p = 0.08), or combined outcome (3.0% vs. 4.9%, p = 0.09). The interaction between symptomatic status and procedure type was not significant, indicating the association of symptomatic status with 30-day mortality (p = 0.29) or the combined periprocedural outcome (p = 0.57) were similar in cases receiving CEA and CAS. CONCLUSION: Early outcomes after CEA and CAS for carotid artery stenosis appear to be similar in a "real-world" sample and comparable to clinical trials. Patients undergoing CAS were more likely to be younger and surgically have higher risk based on baseline characteristics likely reflecting clinical practice case selection.

Topical vancomycin to reduce surgical-site infections in neurosurgery: Study protocol for a multi-center, randomized controlled trial.

Surgical-site infections (SSIs) account for 20% of all healthcare-associated infections, are the most common nosocomial infection among surgical patients, and are a focus of quality improvement initiatives. Despite implementation of many quality care measures (e.g. prophylactic antibiotics), SSIs remain a significant cause of morbidity, mortality, and economic burden, particularly in the field of neurosurgery. Topical vancomycin is increasingly utilized in instrumented spinal and cardiothoracic procedures, where it has been shown to reduce the risk of SSIs. However, a randomized controlled trial assessing its efficacy in the general neurosurgical population has yet to be done. The principle aim of "Topical Vancomycin for Neurosurgery Wound Prophylaxis" (NCT02284126) is to determine whether prophylactic, topical vancomycin reduces the risk of SSIs in the adult neurosurgical population. This prospective, multicenter, patient-blinded, randomized controlled trial will enroll patients to receive the standard of care plus topical vancomycin, or the standard of care alone. The primary endpoint of this study is a SSI by postoperative day (POD) 30. Patients must be over 18years of age. Patients are excluded for renal insufficiency, vancomycin allergy, and some ineligible procedures. Univariate analysis and logistic regression will determine the effect of topical vancomycin on SSIs at 30days. A randomized controlled trial is needed to determine the efficacy of this treatment. Results of this trial are expected to directly influence the standard of care and prevention of SSIs in neurosurgical patients.

Numerous Fusiform and Saccular Cerebral Aneurysms in Central Nervous System Lupus Presenting with Ischemic Stroke.

Central nervous system (CNS) involvement occurs in up to 50% of patients with systemic lupus erythematosus (SLE). Cerebral aneurysm formation is a rare complication of CNS lupus. The majority of these patients present with subarachnoid hemorrhage. We report a patient with an active SLE flare who presented with a recurrent ischemic stroke and was found to have numerous unruptured fusiform and saccular aneurysms in multiple vascular territories. He was treated with high-dose steroid and rituximab along with aspirin and blood pressure control for stroke prevention.

Transoral C2 biopsy and vertebroplasty.

Pathologic fractures involving the C2 vertebral body and odontoid process pose a unique dilemma, as the surgical approach for direct odontoid process screw fixation has several limitations. There have been a small number of transoral approach C2 vertebroplasty or kyphoplasty reported in the literature. Previous attempts were performed utilizing fluoroscopy or CT guidance. We report a case of a fluoroscopically guided transor-al approach vertebroplasty in a patient with a lytic lesion involving the C2 vertebral body, extending into the odontoid process with an underlying pathologic fracture. This case is unique as two separate punctures were required in order to adequately stabilize the pathologic fracture, CTA was performed preoperatively to better evaluate regional vasculature, and a post-procedure rotational flat panel CT was performed to assess cement placement.

Endoscopic endonasal transclival approach to a ventral pontine pediatric ependymoma.

The authors report a case of a recurrent pediatric ventral pontine ependymoma that they resected through an endonasal endoscopic transclival approach. Regarding the options for a surgical approach to ventral pontine tumors, traditional far-lateral approaches are associated with considerable morbidity due to the required muscle mobilization, brain retraction, and in-line obstruction of cranial nerves before reaching the target. The endoscopic endonasal transclival approach was made appealing by eliminating all of these concerns. The patient's fully pneumatized sphenoid sinus, laterally displaced basilar artery, and the direct ventral location of the bulky disease all further supported this unconventional choice of surgical corridor to achieve a palliative brainstem decompression of an incurable recurrence.