Endovascular Parent Vessel Occlusion Versus Flow Diversion in the Treatment of Large and Giant Aneurysms: A Randomized Comparison.

OBJECTIVE: Parent vessel occlusion (PVO) is a time-honored treatment for unclippable or uncoilable intracranial aneurysms. Flow diversion (FD) is a recent endovascular alternative that can occlude the aneurysm and spare the parent blood vessel. Our aim was to compare outcomes of FD with endovascular PVO. METHODS: This is a prespecified treatment subgroup analysis of the Flow diversion in Intracranial Aneurysms trial (FIAT). FIAT was an investigator-led parallel-group all-inclusive pragmatic randomized trial. For each patient, clinicians had to prespecify an alternative management option to FD before stratified randomization. We report all patients for whom PVO was selected as the best alternative treatment to FD. The primary outcome was a composite of core-lab determined angiographic occlusion or near-occlusion at 3-12 months combined with an independent clinical outcome (mRS<3). Primary analyses were intent-to-treat. There was no blinding. RESULTS: There were 45 patients (16.2% of the 278 FIAT patients randomized between 2011 and 2020 in 3 centers): 22 were randomly allocated to FD and 23 to PVO. Aneurysms were mainly large or giant (mean 22 mm) anterior circulation (mainly carotid) aneurysms. A poor primary outcome was reached in 11/22 FD (50.0%) compared to 9/23 PVO patients (39.1%) (RR: 1.28, 95% CI [0.66-2.47]; P = 0.466). Morbidity (mRS >2) at 1 year occurred in 4/22 FD and 6/23 PVO patients. Angiographic results and serious adverse events were similar. CONCLUSIONS: The comparison between PVO and FD was inconclusive. More randomized trials are needed to better determine the role of FD in large aneurysms eligible for PVO.

Gaze Behaviors of Neurosurgeon in Performing Gross Movements under Microscope.

BACKGROUND: Frequent intermittent bleeding control and suction are often necessary during microneurosurgical procedures. We compared the visual searching strategy that guides these types of gross hand movements between expert surgeons and neurosurgical residents. METHODS: A total of 70 trials of a microsurgical task consisting of moving a cotton ball with bipolar forceps and a suction instrument under the microscope were recorded. Based on surgical videos, we extracted total task time, boarding time, gaze-tool time gap, number of fixations during the boarding time, and target-locked fixation duration. A comparison of these measures between experts and resident surgeons were performed. RESULTS: No significant difference was found for total task time, boarding time, and number of fixations during the boarding time between the 2 groups of surgeons. However, we found significant differences in the measure of gaze-tool time gap (P < 0.001, partial η2 = 0.54) and the target-locked fixation (P < 0.001, partial η2 = 0.24). Specifically, expert microsurgeons' eyes move to the target board earlier before their tools in hands move (1.01 ± 0.30 seconds) compared with resident microsurgeons (0.44 ± 0.17 seconds). The target-locked fixation duration was also longer among experts comparing to residents (experts: 1.16 ± 0.82 seconds, residents: 0.40 ± 0.30 seconds). CONCLUSIONS: Task time analysis for this basic microsurgical task is not sufficient to evaluate participants' level of expertise. Gaze behavior analysis helps to reveal hidden differences between experts and residents. This research provides more evidence that supports the use of gaze analysis for assessing surgeons' skills in microsurgery.

The Utility of Superselective Rotational Angiography for Frameless Stereotactic Navigation During Craniotomy for Micro-Arteriovenous Malformation.

BACKGROUND: Micro-arteriovenous malformations (AVMs) can present challenges to neurosurgeons with respect to localization during resection. We sought to describe a novel method that merges super-selective 3-dimensional angiographic images with magnetic resonance imaging (MRI) sequences to facilitate frameless stereotaxic navigation during AVM surgery. METHODS: A retrospective analysis was performed comprising cases that employed merging of angiographic and MRI images for navigation purposes. Baseline clinical and imaging features were recorded. The technique and operative experiences were analyzed descriptively and presented alongside detailed illustrative cases. RESULTS: During the review period, 11 cases were identified where this technique was employed. Successful image acquisition and merging was possible in all cases. Complete obliteration of the target pathology was achieved in all cases. Precise localization of the micro-AVMs minimized dissection in eloquent cortex. CONCLUSIONS: Superselective 3-dimensional angiographic images merged to baseline MRI sequences facilitates planning and navigation during surgery for micro-AVMs.

Eye-Hand Coordination of Neurosurgeons: Evidence of Action-Related Fixation in Microsuturing.

OBJECTIVE: We examined performance differences between expert and novice neurosurgeons under a surgical microscope with the goal to evaluate surgical expertise. METHODS: The Tobii eye-tracker was used to record surgeons' eye movements while they performed a microsuturing task. A total of 19 expert and 18 novice trials were recorded under the microscope. Surgical videos were annotated to label subtasks and critical actions. Total suturing time and subtask times were also compared between novice and expert surgeons. At 3 critical and discrete surgical actions (needle piercing into tissue, exiting, and thread cutting) we examined eye fixation that was directly coupled to each of these actions. RESULTS: Compared with novices, expert surgeons completed the suture with shorter total time (258.52 ± 102.14 seconds vs. 330.02 ± 96.52 seconds, P = 0.038), penetration time (17.15 ± 3.50 seconds vs. 26.26 ± 18.58 seconds, P = 0.043), and knot-tying time (194.63 ± 94.55 seconds vs. 262.52 ± 79.05 seconds, P = 0.025). On average, experts displayed longer fixation (1.62 seconds) and preaction fixation time (1.3 seconds) than novices (fixation time = 1.24 seconds, P = 0.048; preaction fixation = 0.82 seconds, P = 0.005)). Experts maintained their visual engagement constantly over the 3 levels of subtasks while novices required a longer fixation time for the challenging piercing action than for the exiting and cutting action. CONCLUSIONS: The action-related fixation can be used to evaluate microsurgeons' level of expertise and in surgical education for gaze training.

Neurosurgical performance between experts and trainees: Evidence from drilling task.

BACKGROUND: Lumbar laminectomy is a common neurosurgery that requires precise manipulation of power drills. We examined the fine movement controls of novice neurosurgeons in drilling tasks and compared its accuracy to expert surgeons' performance. METHODS: Four experts and three novice neurosurgeons performed a lumbar laminectomy on a three-dimensional printed spine model. Scene video and surgeons' eye movements were recorded. Independent sample t-Tests were conducted on the number of jump, total fixation durations, pre-jump fixation durations, post-jump fixation durations and jump distances over novice and expert surgeons. RESULTS: No statistically significant differences were recorded in terms of total fixations and pre-jump fixation durations. However, novices had more jumping events, greater jump distances and longer post-jump fixation durations when compared to expert neurosurgeons. CONCLUSION: Differences in movement accuracy and eye measures were found between expert and novice neurosurgeons during a simulated microscopic lumbar laminectomy. A more comprehensive understanding of surgeon's fine movement control mechanism and eye-hand coordination in microsurgery is essential for us before building an enhanced training protocol for surgical residents in neurosurgery.

Surgical or Endovascular Management of Middle Cerebral Artery Aneurysms: A Randomized Comparison.

OBJECTIVE: There are few randomized data comparing clipping and coiling for middle cerebral artery (MCA) aneurysms. We analyzed results from patients with MCA aneurysms enrolled in the CURES (Collaborative UnRuptured Endovascular vs. Surgery) and ISAT-2 (International Subarachnoid Aneurysm Trial II) randomized trials. METHODS: Both trials are investigator-led parallel-group 1:1 randomized studies. CURES includes patients with 3-mm to 25-mm unruptured intracranial aneurysms (UIAs), and ISAT-2 includes patients with ruptured aneurysms (RA) for whom uncertainty remains after ISAT. The primary outcome measure of CURES is treatment failure: 1) failure to treat the aneurysm, 2) intracranial hemorrhage during follow-up, or 3) residual aneurysm at 1 year. The primary outcome of ISAT-2 is death or dependency (modified Rankin Scale score >2) at 1 year. One-year angiographic outcomes are systematically recorded. RESULTS: There were 100 unruptured and 71 ruptured MCA aneurysms. In CURES, 90 patients with UIA have been treated and 10 await treatment. Surgical and endovascular management of unruptured MCA aneurysms led to treatment failure in 3/42 (7%; 95% confidence interval [CI], 0.02-0.19) for clipping and 13/48 (27%; 95% CI, 0.17-0.41) for coiling (P = 0.025). All 71 patients with RA have been treated. In ISAT-2, patients with ruptured MCA aneurysms managed surgically had died or were dependent (modified Rankin Scale score >2) in 7/38 (18%; 95% CI, 0.09-0.33) cases, and 8/33 (24%; 95% CI, 0.13-0.41) for endovascular. One-year imaging results were available in 80 patients with UIA and 62 with RA. Complete aneurysm occlusion was found in 30/40 (75%; 95% CI, 0.60-0.86) patients with UIA allocated clipping, and 14/40 (35%; 95% CI, 0.22-0.50) patients with UIA allocated coiling. Complete aneurysm occlusion was found in 24/34 (71%; 95% CI, 0.54-0.83) patients with RA allocated clipping, and 15/28 (54%; 95% CI, 0.36-0.70) patients with RA allocated coiling. CONCLUSIONS: Randomized data from 2 trials show that better efficacy may be obtained with surgical management of patients with MCA aneurysms.

Canadian stroke best practice recommendations: Management of Spontaneous Intracerebral Hemorrhage, 7th Edition Update 2020.

Spontaneous intracerebral hemorrhage is a particularly devastating type of stroke with greater morbidity and mortality compared with ischemic stroke and can account for half or more of all deaths from stroke. The seventh update of the Canadian Stroke Best Practice Recommendations includes a new stand-alone module on intracerebral hemorrhage, with a focus on elements of care that are unique or affect persons disproportionately relative to ischemic stroke. Prior to this edition, intracerebral hemorrhage was included in the Acute Stroke Management module and was limited to its management during the first 12 h. With the growing evidence on intracerebral hemorrhage, a separate module focused on this topic across the care continuum was added. In addition to topics related to initial clinical management, neuroimaging, blood pressure management, and surgical management, new sections have been introduced addressing topics surrounding inpatient complications such as venous thromboembolism, seizure management, and increased intracranial pressure, rehabilitation as well as issues related to secondary management including lifestyle management, maintaining a normal blood pressure and antithrombotic therapy, are addressed. The Canadian Stroke Best Practice Recommendations (CSBPR) are intended to provide up-to-date evidence-based guidelines for the prevention and management of stroke and to promote optimal recovery and reintegration for people who have experienced stroke, including patients, families, and informal caregivers.

The second-generation eCLIPs Endovascular Clip System: initial experience.

OBJECTIVE Treatment of wide-necked intracranial aneurysms is associated with higher recanalization and complication rates; however, the most commonly used methods are not specifically designed to work in bifurcation lesions. To address these issues, the authors describe the evolution in the design and use of the eCLIPs (Endovascular Clip System) device, a novel hybrid stent-like assist device with flow diverter properties that was first described in 2008. METHODS A registry was established covering 13 international centers at which patients were treated with the second-generation eCLIPs device. Aneurysm morphology and rupture status, device neck coverage, coil retention, and procedural and late morbidity and mortality were recorded. For those patients who had undergone successful implantation more than 6 months earlier, the final imaging and clinical follow-up results and need for re-treatment were recorded. RESULTS Thirty-three patients were treated between June 2013 and September 2015. Twenty-five (76%) patients had successful placement of an eCLIPs device; 23 (92%) of these 25 patients had complete data. Eight cases of nondeployment occurred during the 1st year of use, consistent with a learning curve; no failures of deployment occurred thereafter. Two periprocedural transient ischemic attacks and 2 asymptomatic thrombotic events occurred. Twenty-one (91%) of 23 patients underwent follow-up at an average of 8 months (range 3-18 months); 9 (42.9%) of these 21 patients demonstrated an improvement in Raymond grade at follow-up; no cases of worsening Raymond grade were recorded, and 17 (81.0%) patients sustained a modified Raymond-Roy Classification class of I or II angiographic result at follow-up. Two delayed ruptures were recorded, both in previously coiled, symptomatic giant aneurysms where the device was used as a part of a salvage strategy. CONCLUSIONS The second-generation eCLIPs device is a viable treatment option for bifurcation aneurysms. The aneurysm occlusion rates in this initial clinical series are comparable to the initial experience with other bifurcation support devices.

Surgical clipping or endovascular coiling for unruptured intracranial aneurysms: a pragmatic randomised trial.

BACKGROUND: Unruptured intracranial aneurysms (UIAs) are increasingly diagnosed and are commonly treated using endovascular treatment or microsurgical clipping. The safety and efficacy of treatments have not been compared in a randomised trial. How to treat patients with UIAs suitable for both options remains unknown. METHODS: We randomly allocated clipping or coiling to patients with one or more 3-25 mm UIAs judged treatable both ways. The primary outcome was treatment failure, defined as: initial failure of aneurysm treatment, intracranial haemorrhage or residual aneurysm on 1-year imaging. Secondary outcomes included neurological deficits following treatment, hospitalisation >5 days, overall morbidity and mortality and angiographic results at 1 year. RESULTS: The trial was designed to include 260 patients. An analysis was performed for slow accrual: 136 patients were enrolled from 2010 through 2016 and 134 patients were treated. The 1-year primary outcome, available for 104 patients, was reached in 5/48 (10.4% (4.5%-22.2%)) patients allocated surgical clipping, and 10/56 (17.9% (10.0%-29.8%)) patients allocated endovascular coiling (OR: 0.54 (0.13-1.90), p=0.40). Morbidity and mortality (modified Rankin Scale>2) at 1 year occurred in 2/48 (4.2% (1.2%-14.0%)) and 2/56 (3.6% (1.0%-12.1%)) patients allocated clipping and coiling, respectively. New neurological deficits (15/65 vs 6/69; OR: 3.12 (1.05-10.57), p=0.031), and hospitalisations beyond 5 days (30/65 vs 6/69; OR: 8.85 (3.22-28.59), p=0.0001) were more frequent after clipping. CONCLUSION: Surgical clipping or endovascular coiling of UIAs did not show differences in morbidity at 1 year. Trial continuation and additional randomised evidence will be necessary to establish the supposed superior efficacy of clipping.

Mannitol dosing error during interfacility transfer for intracranial emergencies.

OBJECT: Mannitol is commonly used to treat elevated intracranial pressure (ICP). The authors analyzed mannitol dosing errors at peripheral hospitals prior to or during transport to tertiary care facilities for intracranial emergencies. They also investigated the appropriateness of mannitol use based on the 2007 Brain Trauma Foundation guidelines for severe traumatic brain injury. METHODS: The authors conducted a retrospective review of the Shock Trauma Air Rescue Society (STARS) electronic patient database of helicopter medical evacuations in Alberta, Canada, between 2004 and 2012, limited to patients receiving mannitol before transfer. They extracted data on mannitol administration and patient characteristics, including diagnosis, mechanism, Glasgow Coma Scale score, weight, age, and pupil status. RESULTS: A total of 120 patients with an intracranial emergency received a mannitol infusion initiated at a peripheral hospital (median Glasgow Coma Scale score 6; range 3-13). Overall, there was a 22% dosing error rate, which comprised an underdosing rate (<0.25 g/kg) of 8.3% (10 of 120 patients), an overdosing rate (>1.5 g/kg) of 7.5% (9 of 120), and a nonbolus administration rate (>1 hour) of 6.7% (8 of 120). Overall, 72% of patients had a clear indication to receive mannitol as defined by meeting at least one of the following criteria based on Brain Trauma Foundation guidelines: neurological deterioration (11%), severe traumatic brain injury (69%), or pupillary abnormality (25%). CONCLUSIONS: Mannitol administration at peripheral hospitals is prone to dosing error. Strategies such as a pretransport checklist may mitigate this risk.

Arteriovenous fistula and pseudoaneurysm of the anterior spinal artery caused by an epidural needle in a 5-year-old patient.

Authors present the case of a 5-year-old patient with a spinal arteriovenous fistula (AVF) and pseudoaneurysm of the anterior spinal artery (ASA) caused by a traumatic epidural needle stick injury. A discussion and relevant review of the literature follow. The boy had a remote history of a liver transplant and required neuraxial blockade for an unrelated abdominal surgical procedure. Initial insertion of the epidural needle at the T9-10 interspace yielded blood. A second attempt at T10-11 was successful. Delayed left leg weakness developed on postoperative Day 8, with an MR image showing a track injury through the cord and a ventral subarachnoid hematoma. Laminectomies from T-9 to T-11were performed emergently to decompress the spinal cord. The dura mater was opened, the ventral hematoma was evacuated, and brisk venous bleeding was controlled with cauterization. Postoperative spinal angiography demonstrated an AVF and pseudoaneurysm of the ASA. Repeat angiography at postoperative Week 4 demonstrated complete resolution of the AVF and pseudoaneurysm, probably due to intraoperative cauterization of the draining vein. The patient underwent a short course of rehabilitation and had no clinical or electrophysiological evidence of spinal cord damage at the 20-month follow-up. One should be cognizant of the possibility of a cord injury in a patient with new-onset neurological deficits following an interventional spine procedure. Neuroimaging is essential for prompt diagnosis and treatment.

Proximity to the treating centre and outcomes following subarachnoid hemorrhage.

BACKGROUND: In the management of subarachnoid hemorrhage (SAH), the potential for early complications and the centralization of limited resources often challenge the delivery of timely neurosurgical care. We sought to determine the impact of proximity to the accepting neurosurgical centre on outcomes following aneurysmal SAH. METHODS: Using administrative data, we analyzed patients undergoing treatment for aneurysmal subarachnoid hemorrhage at neurosurgical centres in Ontario between 1995 and 2004. We compared mortality for patients receiving treatment at a centre in their county (in-county) versus those treated from outside counties (out-of-county). We also examined the impact of distance from the patient's residence to the treating centre. RESULTS: The mortality rates were significantly lower for in-county versus out-of-county patients (23.5% vs. 27.6%, p=0.009). This advantage remained significant after adjusting for potential confounders (HR=0.84, p=0.01). The relationship between distance from the treating centre and mortality was biphasic. Under 300 km, mortality increased with increasing distance. Over 300 km, a survival benefit was observed. CONCLUSIONS: Proximity to the treating neurosurgical centre impacts survival after aneurysmal SAH. These results have significant implications for the triage of these critically ill patients.

Carotid revascularization: an update.

Symptomatic extracranial internal carotid artery stenosis poses a high short-time risk of ischemic cerebral stroke, as high as 20% to 30% in the first three months. Timely performed carotid endarterectomy (CEA) has been shown to be highly effective in reducing this risk although, in recent years, there has been great interest in replacing this procedure with less invasive carotid angioplasty and stenting (CAS). In this update we review recent studies and provide recommendations regarding the indications, methods and timing of surgical intervention as well as the anaesthetic management of CEA, and we report on recently published randomized controlled trials comparing CEA to CAS. We also provide recommendations regarding the sometime neglected but important medical management of patients undergoing carotid intervention, including antithrombotic and antihypertension therapy, lipid lowering agents, assistance with smoking cessation, and diabetes control.

The impact of therapeutic modality on outcomes following repair of ruptured intracranial aneurysms: an administrative data analysis. Clinical article.

OBJECT: Enrolling a selected sample of ruptured intracranial aneurysms, the International Subarachnoid Aneurysm Trial (ISAT) found endovascular coiling to be superior to microsurgical clipping. The performance of coiling in a more general population of ruptured aneurysms has not been adequately studied. METHODS: Using provincial administrative data from Ontario, the authors conducted a retrospective cohort study of adult patients with subarachnoid hemorrhage (SAH) who underwent aneurysm repair. The exposure was defined as endovascular versus surgical aneurysm repair. The prespecified primary outcome was time to death or readmission for SAH. Data from the entire cohort were analyzed using a multivariable adjusted Cox proportional hazards model. Propensity scores were used to compare a matched subgroup of patients with aneurysms who had similar baseline characteristics. The potential impact of unmeasured confounding was assessed using sensitivity analysis. RESULTS: Between 1995 and 2004, 2342 aneurysms were clipped and 778 were coiled in Ontario. The proportion of aneurysms treated by coiling increased steadily over time. In the adjusted analysis of the entire cohort, endovascular coiling was associated with a significantly increased hazard of death or SAH readmission (hazard ratio 1.25 [95% CI 1.00­1.55], p = 0.04). Similar results were obtained from the propensity score matched analysis (hazard ratio 1.25 [95% CI 1.04­1.50], p = 0.02). Measures of procedural morbidity and mortality were not significantly different between groups. CONCLUSIONS: The results of the current analysis call into question the generalizability of the ISAT to all ruptured aneurysms. Given the limitations inherent in this form of analysis, further clinical studies­rigorously assessing the performance of endovascular therapy in patients with non-ISAT-like aneurysms­are indicated.

Shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage: incidence, predictors, and revision rates. Clinical article.

OBJECT: Chronic shunt-dependent hydrocephalus is a recognized complication of aneurysmal subarachnoid hemorrhage. While its incidence and risk factors have been well described, the long-term performance of shunts in this setting has not been not widely reported. METHODS: Using administrative databases, the authors derived a retrospective cohort of patients undergoing treatment of a ruptured aneurysm in Ontario, Canada, between 1995 and 2005. The authors determined the incidence of shunt-dependent hydrocephalus and analyzed putative risk factors. Mortality rates and indicators of morbidity were recorded. Patients were followed up for the occurrence of shunt failure over time. RESULTS: Of 3120 patients in the cohort, 585 (18.75%) developed shunt-dependent hydrocephalus. On multivariate analysis, age, acute hydrocephalus, ventilation on admission, aneurysms in the posterior circulation and giant aneurysms were all significant predictors of shunt-dependent hydrocephalus. The mortality rate was not increased in patients with chronic hydrocephalus (hazard ratio 1.04, p = 0.63); however, indicators of morbidity were increased in these patients. Of the 585 patients with shunt-dependent hydrocephalus, only 173 (29.6%) underwent a subsequent revision procedure. Ninety-eight percent of these revisions were completed within 6 months. Subsequent revisions occurred more frequently. On multivariate analysis, significant predictors of shunt revision included aneurysm location in the posterior circulation and endovascular treatment of the initial ruptured aneurysm. CONCLUSIONS: Shunt-dependent hydrocephalus affects a significant proportion of subarachnoid hemorrhage survivors, contributing to additional morbidity among these patients. Shunt failures occur less frequently in patients who underwent treatment for a ruptured aneurysm than with other forms of hydrocephalus. Most failures occur within 6 months, suggesting that shunt dependency may be transient in the majority of patients.