Mechanical thrombectomy with a balloon-guide catheter: sheathless transradial versus transfemoral approach

BACKGROUND

The transradial approach (TRA) for mechanical thrombectomy (MT) for acute ischemic stroke has been limited by the size of catheters usable in the radial artery, with the smaller access site precluding balloon-guide catheter (BGC) use. However, promising results have been reported for a TRA with a sheathless BGC (sTRA). We sought to perform a comparative study of MT with a BGC via the sTRA versus the transfemoral approach (TFA).

METHODS

A retrospective review of our MT database was conducted. Baseline, procedure-related, and outcome data were compared for patients aged ≥18 years with anterior circulation large vessel occlusion, Alberta Stroke Program Early CT Score ≥6, and prestroke modified Rankin Scale score ≤2 treated with either approach.

RESULTS

Ninety-three consecutive patients (34 sTRA and 59 TFA) were included. Both groups had similar demographics, comorbidities, stroke severity, intravenous alteplase use, and occlusion location. Mean time from puncture to final recanalization was faster in the sTRA group (29 vs 36 min, p=0.059) despite a higher access site crossover rate in the sTRA group (11.8% vs 0%, p=0.016). There were no differences between groups regarding last modified Thombolysis in Cerebral Infarction score; first-pass or modified first-pass effect; time from last known well to puncture; use of stent-retriever, aspiration, or combination first approach; number of passes; symptomatic intracranial hemorrhage; hospital stay; 90-day functional independence; and mortality. National Institutes of Health Scale score and modified first-pass effect were the only independent predictors of poor outcomes.

CONCLUSIONS

Comparable patients treated with MT via the sTRA or TFA had similar angiographic and clinical outcomes.

Rist Guide Catheter for Endovascular Procedures: Initial Case Series from a Single Center

BACKGROUND

The transradial approach (TRA) for endovascular procedures has become a frequent practice in neurointervention. Advantages of the TRA include less access-site complications, early ambulation, and less postprocedural pain. The Rist 079 radial access guide catheter (Medtronic) is the first device designed specifically for neurointerventions performed through the TRA. In this study, we report our initial experience with the Rist catheter in a variety of neurointerventional procedures, aiming to evaluate the performance of this device and discuss its limitations.

METHODS

A prospectively maintained database was retrospectively searched to identify patients who underwent procedures using the Rist catheter. Information on demographics, procedural details, and complications was recorded.

RESULTS

Seventy-eight patients were included in the study, with a mean age of 60.3 years (range, 25-92 years); 45 (57.7%) were men. The interventional or diagnostic procedure was successfully completed in 77 patients (98.7%). The radial artery was the primary access-site choice in 71 patients (91%). The most frequent type of procedures performed were coiling or stent-assisted coiling (16.7%) and angioplasty and stenting (16.7%), followed by middle meningeal artery embolization (14.1%). Crossover to femoral artery access while maintaining use of the Rist was done in 5 cases (6.4%). Reasons for access or procedural failure included anatomical anomaly of the target vessel, unfavorable geometry of the great vessels, and proximal tortuosity of the supra-aortic vessels.

CONCLUSION

We demonstrated a high success rate with use of the Rist catheter system for a variety of procedures.

Acute isolated posterior cerebral artery stroke treated with mechanical thrombectomy: A single-center experience and review of the literature

BACKGROUND

Acute isolated posterior cerebral artery (PCA) occlusions account for 5-10% of all ischemic events. Due to peculiar patient presentation, the potential benefit of mechanical thrombectomy (MT) remains controversial. We evaluated the safety, feasibility, and effectiveness of MT in our patients and compared our results with the literature review conducted.

METHODS

Charts were reviewed retrospectively for consecutive patients diagnosed with acute PCA stroke who underwent MT. Demographics, procedural, and follow-up details were noted. For the literature review, a systematic search of PubMed, MEDLINE, and EMBASE databases was conducted for the keywords "posterior cerebral artery" and "thrombectomy" for articles published between January 1, 2010 and June 30, 2021. Estimated rates for recanalization, favorable outcomes (modified Rankin Scale [mRS] score 0-2), symptomatic intracerebral hemorrhage (sICH), and mortality were extracted.

RESULTS

Our cohort included 21 patients. Mean age was 71.2 years (standard deviation [SD] ± 10.2). Median National Institutes of Health Stroke Scale (NIHSS) presentation score was 9 (interquartile range [IQR] 5-15), with visual symptoms reported in 12(57.1%) patients. Overall, final modified thrombolysis in cerebral infarction (mTICI) 2b-3 was achieved in 17 patients (80.9%) with first-pass mTICI 2b-3 attained in 8 (38.1%). Postprocedure sICH occurred in 1 (4.8%) patient. Fifteen (71.4%) patients had a 0-2 mRS score at 90 days. Visual symptoms resolved in 10 of 12(83.3%) patients. Mortality occurred in 2 (9.5%) patients. For the systematic review, cohorts from 4 articles plus ours were included, totaling 222 patients. The estimated rate of successful recanalization was 85.25% (95% confidence interval[CI], 73.05%-97.45%), sICH was 3.60% (95% CI, 1.11%-6.09%), and mortality was 10.51% (95% CI, 5.88%-15.15%).

CONCLUSION

The results of our series and systematic review indicate MT as a potentially safe and effective treatment modality for acute PCA stroke. These results also indicate that patient selection and assessment may be the key in obtaining favorable outcomes.

An anatomic assessment of the intercavernous sinuses and review of the literature

Background As expanded endoscopic endonasal approaches are gaining popularity, a thorough understanding of the anatomy of the intercavernous sinuses is pertinent to avoid bleeding complications. There have been few studies reporting the presence and dimensions of the anterior (AIS), posterior (PIS), and inferior (IIS) intercavernous sinuses. We performed a cadaveric study to better understand these structures. Methods Colored latex was injected into the arterial and venous trees of seventeen cadaveric heads. Dissections assessed the presence and dimensions of the anterior, posterior, and inferior intercavernous sinuses. In an additional 3 specimens, the sellar contents were subjected to histologic analysis. Results In thirteen specimens (59%), all three sinuses were identified. In 5 specimens (33%), only the anterior and posterior intercavernous sinuses could be identified, and in one specimen, only an anterior and inferior sinus were identified. An AIS was identified in all 20 (100%) specimens, PIS in 17 (85%), and an IIS in 13 (66)%. In two specimens (10%), the AIS covered the entire face of the sella. Dimensions of the AIS averaged 1.7 x 11.7 x 2.8 mm, PIS averaged 1.5 x 10.8 x 1.7 mm, and IIS averaged 8.7 x 11.8 x 1.0 mm when present. Conclusion All examined specimens demonstrated the presence of an anterior intercavernous sinus, and most had a posterior intercavernous sinus. The presence of an inferior intercavernous sinus was more variable. Preoperative awareness of these sinuses is helpful in planning transphenoidal surgery in order to minimize the risk of bleeding.

The impact of brain atrophy on the outcomes of mechanical thrombectomy

Objective:

Pre-existing brain atrophy may affect the outcomes of patients treated with mechanical thrombectomy (MT) for large-vessel-occlusion because it is an indicator of low brain reserve. We performed a systematic literature review to assess the impact of brain atrophy on MT-related clinical outcomes.

Methods:

We conducted a systematic search of PubMed, MEDLINE, EMBASE, and Cochrane Library databases from inception to March 2021 using keywords with Boolean operators(“brain atrophy”; “atrophy”; “white matter”; and “thrombectomy”). Articles published in English that evaluated the impact of pre-existing brain atrophy on outcomes of MT-treated acute ischemic stroke were eligible for inclusion.

Results:

Four articles were included. Brain atrophy index was a predictor of mortality (odds ratio [OR]:1.81–1.87, 95% confidence interval [CI]:1.16–2.93) after adjustments for age and white matter lesions. Global cortical atrophy scale was an independent predictor of futile recanalization (OR 1.15, 95% CI 1.08–1.22) in multivariate-adjusted logistic regression. Automated measurement of CSF identified increasing volumes associated with reduced 3-month functional independence and higher modified Rankin scale scores. STandards for ReportIng Vascular changes on Neuroimaging criteria for brain atrophy were associated with unfavorable outcome in ordinal-shift analysis (OR 2.72, 95% CI 1.25–5.91).

Conclusions:

The few studies available highlight heterogeneity of neuroimaging methodologies for assessing brain atrophy and difficulty addressing the multiple confounders involved in clinical outcomes. More consistent, accurate investigation is needed before proposing brain atrophy as a possible parameter to improve patient selection for MT.

Advances in knowledge:

Brain atrophy is associated with many of the clinical confounders frequently present in patients with acute ischemic stroke. Heterogeneity in classification methodologies for brain atrophy and complexity analyzing multiple clinical confounders make it difficult to assess the true impact of this radiological finding on MT-related outcomes.

Mechanical thrombectomy versus intravenous alteplase alone in acute isolated posterior cerebral artery occlusion: a systematic review

BACKGROUND

Acute isolated posterior cerebral artery occlusions (aPCAOs) were excluded or under-represented in major randomized trials of mechanical thrombectomy (MT). The benefit of MT in comparison to intravenous tissue plasminogen activator (alteplase; IV-tPA) alone in these patients remains controversial and uncertain.

METHODS

We performed a systematic search of PubMed, MEDLINE, and EMBASE databases for articles comparing MT with or without bridging IV-tPA and IV-tPA alone for aPCAO using keywords ('posterior cerebral artery', 'thrombolysis' and 'thrombectomy') with Boolean operators. Extracted data from patients reported in the studies were pooled into groups (MT vs IV-tPA alone) for comparison. Estimated rates for favorable outcome (modified Rankin scale score 0-2), symptomatic intracranial hemorrhage (sICH), and mortality were extracted.

RESULTS

Seven articles (201 MT patients, 64 IV-tPA) were included, all retrospective. There was no statistically significant difference between pooled groups in median age, median presentation National Institutes of Health Stroke Scale (NIHSS) score, PCAO segment, and median time from symptom onset to puncture or needle. The recanalization rate was significantly higher in the MT group than the IV-tPA group (85.6% vs 53.1%, p<0.00001). Odds ratios for favorable outcome (OR 1.5, 95% CI 0.8 to 2.5), sICH (OR 1.1, 95% CI 0.2 to 5.5), and mortality (OR 1.4, 95% CI 0.5 to 3.6) did not significantly favor any modality.

CONCLUSIONS

We found no significant differences in odds of favorable outcome, sICH, and mortality in MT and IV-tPA in comparable aPCAO patients, despite superior MT recanalization rates. Equipoise remains regarding the optimal treatment modality for these patients.

Spontaneous resolution of nontraumatic bilateral Barrow Type D indirect carotid-cavernous fistulas: A case report

A Caucasian man in his 60s with a history of Cognard Type IIB dural arteriovenous fistula presented to the emergency room with right eye proptosis, chemosis, hyperemia, epiphora, diplopia, and blurred vision. Magnetic resonance imaging and magnetic resonance angiography revealed spontaneous, bilateral Barrow Type D carotid-cavernous fistulas (CCFs) that were later confirmed through cerebral angiography. The patient had no history of head or ocular trauma. Given the acute nature of presentation and worsening diplopia, the patient was scheduled for transvenous embolization. However, during the preprocedure angiogram, spontaneous resolution of the bilateral CCFs was observed. Complete resolution of all symptoms was noticed during follow-up. Given the rare nature of bilateral, indirect CCFs, our case stands out as the only reported instance whereby resolution of bilateral, indirect CCFs occurred spontaneously without any intervention.

Use of Walrus balloon-guide catheter through sheathless radial approach for mechanical thrombectomy of right middle cerebral artery occlusion

The literature demonstrates a favorable first pass effect with balloon-guide catheter (BGC) for mechanical thrombectomy. An 8F BGC is routinely used with femoral access. We present the first video report of 8F BGC advanced through the radial artery using a sheathless technique (video 1). An approximately 70-year-old patient presented with left-sided hemiplegia, neglect, and dysarthria. A CT angiogram demonstrated right M1 occlusion, and the patient underwent urgent mechanical thrombectomy. Radial approach was preferred owing to patient history of anticoagulation. A 6F Sim Select intermediate catheter was used to minimize the step off as the 8F BGC was advanced into the radial artery over an 035 exchange-length Advantage Glidewire. A skin nick over the Glidewire Advantage facilitated the introduction of the 8F BGC into the radial artery. Standard mechanical thrombectomy using a combination of stent retriever and aspiration catheter (Solumbra technique) was performed, and thrombolysis in cerebral infarction 3 recanalization was achieved after a single pass. The National Institutes of Health Scale score improved from 12 to 4, with mild left facial droop, dysarthria, and decreased speech fluency. The patient was discharged from the hospital on postoperative day 2. Ultrasound should be used for immediate assessment of radial artery size and conversion to femoral access without delay if the radial artery is less than 2.5 mm.neurintsurg;neurintsurg-2021-017985v1/V1F1V1Video 1.

Use of a sheathless 8-French balloon guide catheter (Walrus) through the radial artery for mechanical thrombectomy: technique and case series

BACKGROUND

The effectiveness of transradial stroke thrombectomy has been limited by guide catheter size and lack of good balloon options. In this study we describe our technique for the use of a sheathless 8-French balloon guide catheter (Walrus) through radial access and present our initial clinical experience.

METHODS

This was a retrospective case series of consecutive patients who underwent mechanical thrombectomy for large vessel occlusion using the sheathless catheter over a period of 3 months. Clinical characteristics, procedural details, reperfusion success (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3 grade), first-pass effect (FPE; mTICI reperfusion grade 2c or 3 with a single pass), access site complications and clinical improvement at discharge were recorded. A descriptive analysis was performed.

RESULTS

Among the 10 patients in the series, median age was 77 years (IQR 75-79) and three were women. All patients had a baseline modified Rankin Scale score ≤2. Median admission National Institutes of Health Stroke Scale (NIHSS) score was 12.5 (IQR 9-16). Four patients received intravenous alteplase before mechanical thrombectomy. Eight patients had M1 occlusion and two had proximal M2 occlusion. The median radial artery diameter was 2.5 mm (IQR 2.5-2.7). Successful reperfusion was achieved in all patients. FPE was achieved in six patients. No access site-related complications or post-procedural intracranial hemorrhages occurred. All patients had improvement in NIHSS score at discharge.

CONCLUSIONS

The use of this sheathless catheter for transradial access was safe and feasible. The technique can potentially improve the outcomes of transradial access for stroke intervention.

Intracranial Stenting: Angioplasty Basic Technique, Indications, and Sizing: 2-Dimensional Operative Video

Intracranial atherosclerotic disease (ICAD) is a common cause of stroke. Antiplatelet therapy is the mainstay for symptomatic ICAD treatment. Endovascular management with submaximal angioplasty and/or intracranial stenting is reserved for patients with repeated ischemic events despite optimal medical therapy. We demonstrate intracranial angioplasty and stenting technique, technique indications, and sizing of stent and target vessel diameter. Stenting and angioplasty have been described in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis and Wingspan Stent System Post Market Surveillance trials.1,2 Submaximal angioplasty has also been described.3 This patient, who had been on dual antiplatelet therapy for several months, initially presented with occlusion of the left middle cerebral artery M2 inferior division and underwent mechanical thrombectomy with successful reperfusion. Postoperatively, the patient's symptoms did not improve. Medical management was optimized with heparin infusion. However, repeat stroke study demonstrated M2 inferior division reocclusion. A decision was made to proceed with intracranial angioplasty and stenting. P2Y12 levels were therapeutic. Under moderate conscious sedation, submaximal angioplasty of up to 80% of the normal M2 caliber was attempted. However, we observed persistent high-grade stenosis of the M2 inferior division. The major risk of crossing the lesion for angioplasty is vessel perforation. To safely perform this maneuver, we used a J-configured Synchro-2 microwire (Stryker). Because of the patient's recent thrombectomy, we also had prior tactile feedback about how much resistance was encountered while crossing the occlusion. We then deployed a balloon-mounted intracranial stent for optimal radial force across the stenotic area to restore perfusion. Postoperative computed tomography perfusion showed resolution of the previously noticed perfusion deficit. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, September 2020. With permission.

Social Media Use Among Neurosurgery Trainees: A Survey of North American Training Programs

BACKGROUND

Social media have revolutionized access to educational content. Given the extensive presence of social media, these platforms have the potential to influence neurosurgical training and education of residents and fellows. We explored the attitudes of neurosurgical trainees (postgraduate years 1-9) toward social media and their perceived influence on training and education.

METHODS

This study was a survey of trainees at North American neurosurgery residency programs. A 22-item survey, including 2 free-text questions, was distributed through the Congress of Neurological Surgeons listserv. The survey consisted of questions regarding demographics, social media platform use, and trainee views on social media; their perceived impact on education and job performance was gauged using a 5-point Likert scale. Descriptive analysis was performed.

RESULTS

The survey was disseminated to 1160 neurosurgery trainees, with a response rate of 15.3%. Of 178 respondents, 132 (74.2%) were men; 142 (79.8%) were 25-34 years old. All respondents used social media. The most commonly used platforms were Facebook (87.1%), followed by YouTube (84.3%), Instagram (81.5%), and Twitter (74.7%). The most common reasons for social media use were personal social (89.8%), networking (65.5%), and academic resources (65.0%); 113 respondents (63.5%) reported spending <25% of their time on social media for academics. The Neurosurgical Atlas (63.3%), Congress of Neurological Surgeons (11.2%), and American Association of Neurological Surgeons (10.1%) social media accounts were the most commonly used academic platforms.

CONCLUSIONS

Social media use was ubiquitous among trainees. Although most used social media for personal social communication, most also used it for academic purposes.

Treatment of ruptured intracranial aneurysms with the Woven EndoBridge device: a systematic review

The Woven EndoBridge (WEB) device is a barrel-shaped nitinol mesh deployed within the aneurysmal sac. The absence of metallic mesh in the aneurysm's parent vessel lumen obviates the need for potent antiplatelet therapy, making this device appealing for acutely ruptured aneurysms not amenable to clipping or coiling. To assess the literature regarding WEB treatment of these aneurysms, we performed a comprehensive systematic search of PubMed, MEDLINE, and EMBASE databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Keywords were combined with Boolean operators to increase search sensitivity and specificity ('woven endobridge device' AND 'ruptured'). Nine studies comprising 377 acutely ruptured aneurysms were included. Overall, 82.7% were wide-necked, 85.9% were located in the anterior circulation, and 26.9% of patients presented with poor subarachnoid hemorrhage grade. Intraprocedure and postprocedure complications occurred in 8.4% (95% CI 3.6% to 13.3%) and 1% (95% CI 0% to 2%), respectively. The post-treatment rebleeding rate was 0%. Rates of adequate occlusion (complete occlusion to neck remnant) and retreatment at last follow-up were 84.8% (95% CI 73% to 96.6%) and 4.5% (95% CI 2.2% to 6.8%), respectively. The favorable outcome rate (modified Rankin Scale score 0-2) was 62.2% (95% CI 53% to 71.4%); mortality was 13.6% (95% CI 9.7% to 17.6%). WEB treatment of acutely ruptured aneurysms results in high adequate occlusion rates, low perioperative complication rates, no rebleeding, and low recurrence requiring retreatment. This device is promising for acutely ruptured aneurysms not amenable to clipping or coiling, considering the lower need for antiplatelet regimens during the procedure or follow-up.

Comparison of effectiveness and outcomes among different thrombectomy techniques in acute basilar artery occlusion: a dual-center experience

OBJECTIVE

Acute basilar artery occlusion (BAO) is a rare large-vessel occlusion associated with high morbidity and mortality. Modern thrombectomy with stent retrievers and large-bore aspiration catheters is highly effective in achieving recanalization, but a direct comparison of different techniques for acute BAO has not been performed. Therefore, the authors sought to compare the technical effectiveness and clinical outcomes of stent retriever-assisted aspiration (SRA), aspiration alone (AA), and a stent retriever with or without manual aspiration (SR) for treatment of patients presenting with acute BAO and to evaluate predictors of clinical outcome in their cohort.

METHODS

A retrospective analysis of databases of large-vessel occlusion treated with endovascular intervention at two US endovascular neurosurgery centers was conducted. Patients ≥ 18 years of age with acute BAO treated between January 2013 and December 2020 with stent retrievers or large-bore aspiration catheters were included in the study. Demographic information, procedural details, angiographic results, and clinical outcomes were extracted for analysis.

RESULTS

Eighty-three patients (median age 67 years [IQR 58-76 years]) were included in the study; 33 patients (39.8%) were female. The median admission National Institutes of Health Stroke Scale (NIHSS) score was 16 (IQR 10-21). Intravenous alteplase was administered to 26 patients (31.3%). The median time from symptom onset to groin or wrist puncture was 256 minutes (IQR 157.5-363.0 minutes). Overall, successful recanalization was achieved in 74 patients (89.2%). The SRA technique had a significantly higher rate of modified first-pass effect (mFPE; 55% vs 31.8%, p = 0.032) but not true first-pass effect (FPE; 45% vs 34.9%, p = 0.346) than non-SRA techniques. Good outcome (modified Rankin Scale [mRS] score 0-2) was not significantly different among the three techniques. Poor outcome (mRS score 3-6) was associated with a higher median admission NIHSS score (12.5 vs 19, p = 0.007), a higher rate of adjunctive therapy usage (9% vs 0%, p < 0.001), and a higher rate of intraprocedural complications (10.7% vs 14.5%, p = 0.006). The admission NIHSS score significantly predicted good outcome (OR 0.98, 95% CI 0.97-0.099; p = 0.032). Incomplete recanalization after thrombectomy significantly predicted mortality (OR 1.68, 95% CI 1.18-2.39; p = 0.005).

CONCLUSIONS

The evaluated techniques resulted in high recanalization rates. The SRA technique was associated with a higher rate of mFPE than AA and SR, but the clinical outcomes were similar. A lower admission NIHSS score predicted a better prognosis for patients, whereas incomplete recanalization after thrombectomy predicted mortality.

Mechanical thrombectomy versus intravenous thrombolysis for distal large-vessel occlusion: a systematic review and meta-analysis of observational studies

OBJECTIVE

While several studies have compared the feasibility and safety of mechanical thrombectomy (MT) for distal large-vessel occlusion (LVO) strokes in patients, few studies have compared MT with intravenous thrombolysis (IVT) alone. The purpose of this systematic review was to compare the effectiveness and safety between MT and standard medical management with IVT alone for patients with distal LVOs.

METHODS

PubMed, Google Scholar, Embase, Scopus, Web of Science, Ovid Medline, and Cochrane Library were searched in order to identify studies that directly compared MT with IVT for distal LVOs (anterior cerebral artery A2, middle cerebral artery M3-4, and posterior cerebral artery P2-4). Primary outcomes of interest included a modified Rankin Scale (mRS) score of 0 to 2 at 90 days posttreatment, occurrence of symptomatic intracerebral hemorrhage (sICH), and all-cause mortality at 90 days posttreatment.

RESULTS

Four studies representing a total of 381 patients were included in this meta-analysis. The pooled results indicated that the proportion of patients with an mRS score of 0 to 2 at 90 days (OR 1.16, 95% CI 0.23-5.93; p = 0.861), the occurrence of sICH (OR 2.45, 95% CI 0.75-8.03; p = 0.140), and the mortality rate at 90 days (OR 1.73, 95% CI 0.66-4.55; p = 0.263) did not differ between patients who underwent MT and those who received IVT alone.

CONCLUSIONS

The meta-analysis did not demonstrate a significant difference between MT and standard medical management with regard to favorable outcome, occurrence of sICH, or 90-day mortality. Prospective clinical trials are needed to further compare the efficacy of MT with IVT alone for distal vessel occlusion.

Flow redirection endoluminal device (FRED) for treatment of intracranial aneurysms: A systematic review

INTRODUCTION

The Flow Redirection Endoluminal Device (FRED; MicroVention) is a dual-layered flow diverter used for the treatment of intracranial aneurysms. The objective of this systematic review was to compile device-related safety and effectiveness data.

METHODS

The literature from January 1, 2013 to April 30, 2021 was searched for studies describing use of the FRED for intracranial aneurysm treatment irrespective of aneurysm location and morphology. The review included anterior and posterior circulation ruptured and unruptured saccular, fusiform or dissection, and blister aneurysms. MeSH terms related to "flow re-direction endoluminal device" and "FRED for aneurysms" were used. Data related to indication, complications, and rates of aneurysm occlusion were retrieved and analyzed.

RESULTS

Twenty-two studies with 1729 intracranial aneurysms were included in this review. Overall reported morbidity was 3.9% (range 0-20%). Overall procedure-related mortality was 1.4% (range 0-6%). Complication rates fell into 5 categories: technical (3.6%), ischemic (3.8%), thrombotic or stenotic (6%), hemorrhagic (1.5%), and non-neurological (0.8%). The aneurysm occlusion rate between 0 and 3 months (reported in 11 studies) was 47.8%. The occlusion rate between 4 and 6 months (reported in 14 studies) was 73.8%. Occlusion rates continued to increase to 75.1% at 7-12 months (reported in 10 studies) and 86.6% for follow-up beyond 1 year (reported in 10 studies).

CONCLUSION

This review indicated that the FRED is a safe and effective for the treatment of intracranial aneurysms. Future studies should directly compare the FRED with other flow diverters for a better understanding of comparative safety and effectiveness among the different devices.

Ulnar Artery Access: A Nontraditional Access Site for Diagnostic Cerebral Angiography and Neurointervention: 2-Dimensional Operative Video

Transfemoral access has long been the main access site for cerebral angiography and neurointerventional procedures. Radial access is accepted as an alternative to the traditional transfemoral approach. Ulnar access may be undertaken if the radial artery is occluded or small caliber, or when radial artery preservation is needed. The safety and feasibility of ulnar access for neuroangiographic procedures has been demonstrated.1-3 In this operative video, we demonstrate ulnar artery access in a patient in whom radial artery preservation was desired. We further elaborate on the technical nuances of this access. This nontraditional access site offers the same advantages as radial access, avoiding the need to switch to femoral artery access. A preoperative Allen's test is not necessary. Ultrasound imaging is used to aid in the identification and successful puncture of the ulnar artery. A medial to lateral approach for ulnar artery puncture is advised to avoid injury to the ulnar nerve. Careful application of wrist closure bands avoids hematoma accumulation.  The patient gave informed consent for the procedure and video recording. Institutional review board approval was deemed unnecessary.  Video. © University at Buffalo, May 2021. Used with permission.

Diminishing returns with successive device passes in mechanical thrombectomy for stroke

BACKGROUND

Multiple device passes are associated with complications and poor functional outcomes following mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO).

OBJECTIVE

To characterize the relationship between number of device passes, complications, angiographic outcomes, and clinical outcomes in MT for ELVO.

METHODS

This is a single-center, retrospective cohort study. Individual device passes for MT were evaluated for any change in Thrombolysis in Cerebral Infarction (TICI) score, successful revascularization (TICI 2b or 3), and complications. Outcomes were compared among groups requiring multiple passes with various cut-off points. Risk factors for unfavorable clinical outcome [90 day modified Rankin Scale > 2] were assessed using multivariate analysis.

RESULTS

Successful revascularization was achieved in 75% of 163 patients and 36% required only one device pass. After the second pass, the likelihood of angiographic improvement significantly decreased (p < 0.001). Using multiple cut-off points, higher post-procedural NIHSS scores, mortality rates, and unfavorable 90-day outcomes were associated with a greater number of passes. Multivariate analysis revealed ICA thrombus (comparison: M2, OR: 25, 95% CI 2-275, p = 0.01) and failed revascularization (OR: 68, 95% CI 3.12-1489, p = 0.01) as the only significant predictors of unfavorable clinical outcome. Nonetheless, the likelihood of favorable clinical outcome was higher in patients with an ICA occlusion who were revascularized in < 2 vs. ≥ 2 (44 vs 4%, p = 0.01) or < 3 vs. ≥ 3 (32 vs. 0%, p = 0.02) passes.

CONCLUSION

The likelihood of angiographic improvement in patients with ELVO significantly decreases after the second pass. A greater number of passes is associated with worsened clinical outcomes.

Dual Microcatheter Technique for Coiling of Intracranial Aneurysms: 2-Dimensional Operative Video

Primary coiling of large intracranial aneurysms with complex morphology, such as multiple lobes and a wide neck, is challenging. In these aneurysms, achieving adequate intra-aneurysmal packing density while preventing coil herniation into the parent vessel may be difficult with traditional coiling technique. In the setting of acute aneurysm rupture, alternative treatment options such as stent-assisted coiling or flow diversion may not be feasible due to the need for dual antiplatelets. In this video, we demonstrate the use of a dual microcatheter technique to achieve adequate packing density within a wide-necked, bilobed saccular aneurysm. The patient presented with a ruptured posterior communicating artery aneurysm with Hunt and Hess grade 2 and Fisher grade 4 subarachnoid hemorrhage. A biaxial catheter system was used for primary coiling of the aneurysm. Two .017-inch microcatheters were strategically positioned in the aneurysm lobes. The first coil was deployed through the distal catheter, which created a basket for the second coil to be deployed through the proximal microcatheter. Subsequent simultaneously deployed coils were weaved into each other to form a stable coil mass that prevented coil herniation into the parent vessel. Complete obliteration of the aneurysm was achieved. The patient gave informed consent for the procedures and video recording. Institutional review board approval was deemed unnecessary. Video. ©University at Buffalo Neurosurgery, Inc., January 2020. With permission. 10.1093/ons/opab074 VIDEO 1 Dual Microcatheter Technique for Coiling of Intracranial Aneurysms: 2-Dimensional Operative Video opab074Media1 6236960343001.

Use of N-butyl 2-cyanoacrylate (nBCA) for preoperative tumor embolization

N-butyl 2-cyanoacrylate (nBCA) is a fast-acting liquid adhesive that polymerizes when it comes in contact with blood anions. We present the principles of nBCA preparation and delivery for tumor embolization of a right convexity meningioma in a patient who presented with a 6-month history of word-finding difficulty and memory loss video 1 Angiography of the middle meningeal artery showed a hairpin turn that was not negotiable with a number of different microwires, including the Synchro-2, Chikai 014 and Balt hybrid 008 wire. Due to the tortuous hairpin turn, the microcatheter position was distal to the tumor blush for the convexity meningioma. Given the distal microcatheter position, we opted for nBCA as the liquid embolic of choice for tumor embolization. The time of polymerization for nBCA may be delayed using glacial acetic acid, which makes nBCA ideal when the microcatheter is in a distal position relative to the target location for embolization. The patient underwent successful embolization using nBCA and was taken for a right frontal craniotomy for resection of the meningioma the next day. The intraoperative blood loss was 100 mL and the postoperative MRI showed gross total resection. The patient had an uncomplicated hospital course and was discharged home on post-procedure day 3.neurintsurg;neurintsurg-2021-017400v1/V1F1V1Video 1.

Learning curves for transradial access versus transfemoral access in diagnostic cerebral angiography: a case series

BACKGROUND

The perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications.

OBJECTIVE

To compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator.

METHODS

The first 100-150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1-25, 26-50, 51-75).

RESULTS

We identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25-50 transradial angiograms; and the two other fellows, in <25 transradial angiograms. The two fellows with previous experience had flattened learning curves for both access types. Two patients experienced transient neurologic symptoms postprocedure. Transradial angiograms were associated with significantly fewer access-site complications (3/607, 0.5% vs 22/635, 3.5%, p<0.01). Radial-to-femoral conversion occurred in 1.2% (7/607); femoral-to-radial conversion occurred in 0.3% (2/635). Over time, the proportion of transradial angiographic procedures increased.

CONCLUSION

Technical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.

Walrus Balloon Guide Catheter for Stroke Intervention: Technical Considerations and Clinical Outcomes

BACKGROUND

The use of balloon guide catheters (BGCs) for proximal flow arrest during neurointerventional procedures has been limited owing to the incompatibility of BGCs with large-bore aspiration catheters and difficulty in device navigation. The objective of our study was to describe the use of the Walrus catheter (Q'Apel Medical, Fremont, California, USA), a new 8F BGC, with a variety of aspiration catheters and procedures requiring flow arrest.

METHODS

Consecutive cases using Walrus BGCs for proximal flow arrest during mechanical thrombectomy for acute stroke cases were recorded. The procedure indication, vessel occlusion site, technique, first-pass effect (modified thrombolysis in cerebral infarction score of 2C or 3 after the first recanalization attempt), and complications were recorded and evaluated statistically.

RESULTS

Our study included 57 patients who had undergone mechanical thrombectomy. In addition to mechanical thrombectomy, the Walrus BGC was used in conjunction with the following techniques: stent retrieval in 2 patients (3.5%), stent retrieval followed by aspiration (Solumbra technique) in 41 (71.9%), and aspiration followed by stent retrieval in 14 patients (24.6%). Eight different aspiration catheters were used in 56 of these 57 procedures. The first-pass effect (modified thrombolysis in cerebral infarction score of 2C and 3) was achieved in 36 (63.2%) of 57 procedures. Two patients (3.5%) had experienced intraoperative complications (symptomatic intracerebral hemorrhage) and one patient (1.8%) had died in-hospital.

CONCLUSIONS

Our results have demonstrated that the Walrus BGC is a highly navigable 8F guide catheter compatible with most available aspiration catheters. Owing to its compatibility with most available aspiration catheters and ease of use, the Walrus BGC is a valuable addition to the tools available for mechanical thrombectomy.

Clot imaging characteristics predict first pass effect of aspiration-first approach to thrombectomy

BACKGROUND

The value of clot imaging in patients with emergent large vessel occlusion (ELVO) treated with thrombectomy is unknown.

METHODS

We performed retrospective analysis of clot imaging (clot density, perviousness, length, diameter, distance to the internal carotid artery (ICA) terminus and angle of interaction (AOI) between clot and the aspiration catheter) of consecutive cases of middle cerebral artery (MCA) occlusion and its association with first pass effect (FPE, TICI 2c-3 after a first attempt).

RESULTS

Patients (n = 90 total) with FPE had shorter clot length (9.9 ± 4.5 mm vs. 11.7 ± 4.6 mm, P = 0.07), shorter distance from ICA terminus (11.0 ± 7.1 mm vs. 14.7 ± 9.8 mm, P = 0.048), higher perviousness (39.39 ± 29.5 vs 25.43 ± 17.6, P = 0.006) and larger AOI (153.6 ± 17.6 vs 140.3 ± 23.5, P = 0.004) compared to no-FPE patients. In multivariate analysis, distance from ICA terminus to clot ≤13.5 mm (odds ratio (OR) 11.05, 95% confidence interval (CI) 2.65-46.15, P = 0.001), clot length ≤9.9 mm (OR 7.34; 95% CI 1.8-29.96, P = 0.005), perviousness ≥ 19.9 (OR 2.54, 95% CI 0.84-7.6, P = 0.09) and AOI ≥ 137°^ (OR 6.8, 95% CI 1.55-29.8, P = 0.011) were independent predictors of FPE. The optimal cut off derived using Youden's index was 6.5. The area under the curve of a score predictive of FPE success was 0.816 (0.728-0.904, P < 0.001). In a validation cohort (n = 30), sensitivity, specificity, positive and negative predictive value of a score of 6-10 were 72.7%, 73.6%, 61.5% and 82.3%.

CONCLUSIONS

Clot imaging predicts the likelihood of achieving FPE in patients with MCA ELVO treated with the aspiration-first approach.

Radial first or patient first: a case series and meta-analysis of transradial versus transfemoral access for acute ischemic stroke intervention

BACKGROUND

Few studies have compared technical success and effectiveness of transradial access (TRA) versus transfemoral access (TFA) for mechanical thrombectomy (MT) for acute ischemic stroke (AIS). We compared the two approaches for technical success, effectiveness, and outcomes.

METHODS

We retrospectively compared TRA with TFA for AIS MT at our institute. We additionally performed a systematic review and meta-analysis of studies describing the use of TRA alone or in comparison with TFA for MT. Primary outcomes included rate of successful reperfusion (thrombolysis in cerebral infarction (TICI) >2b), number of passes, access-site complications, and 3- month mortality and favorable functional outcomes (modified Rankin Scale (mRS) score 0-2).

RESULTS

A total of 222 consecutive patients (TRA=93, TFA=129) were included in our case series. The rate of successful reperfusion was significantly higher for the TFA cohort (91.4% vs 79.6%, P=0.01) with lower mean number of passes (1.8±1.2 vs 2.4±1.6, P=0.014). Three-month mortality in the TFA group was lower (22.1% vs 40.9% for the TRA cohort (P=0.004), with a higher rate of favorable functional outcomes (51.3% vs 34.1%, P=0.015). A meta-analysis of 10 studies showed significant heterogeneity in rates of successful reperfusion (57.1% to 95.6%, heterogeneity=67.55%, P=0.001). None of the previous comparative studies reported 3-month mortality and functional outcomes.

CONCLUSIONS

This case series demonstrate a higher successful reperfusion rate, fewer passes, lower 3-month mortality, and improved 3-month functional outcomes with TFA. The systematic review highlights the inadequacy of existing evidence. Prospective comparative studies are needed before a 'radial-first' approach can be adopted for stroke intervention.

Complete flow control using transient concurrent rapid ventricular pacing or intravenous adenosine and afferent arterial balloon occlusion during transvenous embolization of cerebral arteriovenous malformations: case series

BACKGROUND

There are no reports that describe complete flow control using concurrent transient rapid ventricular pacing or intravenous (IV) adenosine and afferent arterial balloon flow arrest to aid transvenous embolization of cerebral arteriovenous malformations (AVM). We describe our experience with the use of this technique in patients undergoing transvenous AVM embolization.

METHODS

Consecutive patients in whom transvenous embolization was attempted at our institute between January 2017 and July 2019 were included. Anatomical AVM features, number of embolization stages, technique of concurrent transient rapid ventricular pacing and afferent arterial balloon flow arrest, complications, and clinical and radiological outcomes were recorded and tabulated.

RESULTS

Transvenous AVM embolization was attempted in 12 patients but abandoned in two patients for technical reasons. Complete embolization was achieved in 10 patients, five of whom had infratentorial AVMs. All 10 had a single primary draining vein. Rapid ventricular pacing was used in nine cases; IV adenosine injection was used in one case to achieve cardiac standstill. Complete AVM nidus obliteration was achieved with excellent neurologic outcome in nine cases, with transvenous embolization alone in two cases, and with staged transarterial followed by transvenous embolization in the others. Two patients developed hemorrhagic complications intraprocedurally. One patient was managed conservatively and the other operatively with AVM excision and hematoma evacuation; both made an excellent recovery without any neurologic deficits at 3 months.

CONCLUSION

Complete flow control using concurrent transient rapid ventricular pacing with afferent arterial balloon flow arrest technique is safe and feasible for transvenous embolization of select AVMs.

Is Endovascular Therapy for Stroke Cost-Effective Globally? A Systematic Review of the Literature

OBJECTIVES

Cost-effectiveness of endovascular therapy (EVT) is a key consideration for broad use of this approach for emergent large vessel occlusion stroke. We evaluated the evidence on cost-effectiveness of EVT in comparison with best medical management from a global perspective.

MATERIALS AND METHODS

This systematic review of studies published between January 2010 and May 2020 evaluated the cost effectiveness of EVT for patients with large vessel occlusion acute ischemic stroke. The gain in quality adjusted life year (QALY) and incremental cost-effectiveness ratio (ICER), expressed as cost per QALY resulting from EVT, were recorded. The study setting (country, economic perspective), decision model, and data sources used in economic models of EVT cost-effectiveness were recorded.

RESULTS

Twenty-five original studies from 12 different countries were included in our review. Five of these studies were reported from a societal perspective; 18 were reported from a healthcare system perspective. Two studies used real-world data. The time horizon varied from 1 year to a lifetime; however, 18 studies reported a time horizon of >10 years. Twenty studies reported using outcome data from randomized, controlled clinical trials for their models. Nineteen studies reported using a Markov model. Incremental QALYs ranged from 0.09-3.5. All studies but 1 reported that EVT was cost-effective.

CONCLUSIONS

Evidence from different countries and economic perspectives suggests that EVT for stroke treatment is cost-effective. Most cost-effectiveness studies are based on outcome data from randomized clinical trials. However, there is a need to study the cost-effectiveness of EVT based solely on real-world outcome data.

Placement of Left Subclavian Origin Stent for Subclavian Steal Syndrome

Subclavian steal syndrome is characterized by the vertebral artery flow inversion as a result of a stenotic lesion in the origin of the subclavian artery. Subclavian origin stenting is an important armamentarium of neurointerventional surgeons. A 79-year-old patient presented with left arm claudication and dizziness while exercising, alongside upper extremity coolness at rest. Examination revealed blood pressure difference of 15 mm Hg in the left arm when compared with the right, with Doppler ultrasonography demonstrating reversal of flow in the left vertebral artery. Aortic arch run with pigtail catheter demonstrated the extent of stenosis and served as a roadmap for stent deployment. Placement of a long sheath across the subclavian stenosis into the aortic arch allowed atraumatic delivery and precise deployment of the covered stent (Video 1). No neurologic deficits were reported postoperatively, with Doppler ultrasonography revealing anterograde flow in the left vertebral artery demonstrating resolution of subclavian steal syndrome.

Rapid temporary coiling of the parent artery for the management of intraprocedural aneurysm rupture

Intraprocedural rupture (IPR) of an intracranial aneurysm is the most feared complication of primary and stent-assisted coiling because it carries a high risk of morbidity and mortality. The endovascular strategy applied to control IPR depends on the cause of the rupture and stage of the procedure. Rupture during primary or stent-assisted coiling is traditionally managed with the use of continued packing, balloon microcatheter placement, or in rare cases, with parent artery sacrifice. In this technical note, we describe the use of temporary coiling of the parent artery to control IPR in three cases. Temporary parent artery coiling creates a subocclusive state, resulting in aneurysmal blood flow reduction without interruption of blood flow to the distal territory. Flow reduction combined with the thrombogenicity of the previously deployed coils results in hemostasis. In the cases presented here, IPR occurred during the late stage of coiling. In each case, parent artery coiling was performed along with heparin reversal. After confirmation of hemostasis, the coils were retrieved to restore normal blood flow. We demonstrate that the technique of temporary parent artery coiling may be a safe and effective option for the management of IPR during primary or stent-assisted coiling.

Endovascular management of radial artery loop for neuroangiography: Case series

Background

Radial loops are rare congenital radial artery anomalies that may pose a significant challenge to successful transradial neuroangiography. In this case series, we describe the anatomy and frequency of radial artery loops and provide a technique for successful navigation of this anatomic anomaly.

Methods

We reviewed our database of radial diagnostic or interventional neuroangiographic procedures to identify cases in which a radial loop was encountered during the procedure. The loop pattern, the presence of an associated recurrent radial artery branch, navigation technique, and procedure-related complications were recorded. A descriptive analysis was performed.

Results

A total of 997 transradial approach procedures were performed over a 9-month period. A radial loop was identified in 10 (1.0%) patients. The average age was 68.6 ± 14.3 years. A microcatheter advanced over a microwire was used to navigate the loop and avoid entry into the recurrent branch. A diagnostic neuroangiographic procedure was performed successfully in 8 cases and an intervention was performed successfully in 1 case. A 360° loop was present in 2 of these cases. In each case, transradial access was performed successfully. In 1 other diagnostic case, transradial access was aborted, and the femoral artery was accessed to perform the procedure.

Conclusions

A radial loop was present in 1% of the cases in this series. Our technical results suggest that this anomaly should not be considered a contraindication to transradial neuroangiography because the procedure was successfully performed in most (9 of 10) cases using a microcatheter system to navigate the loop.

Use of expandable stent retriever for mechanical thrombectomy of the right internal carotid artery terminus occlusion

Background:

Tigertriever (Rapid Medical, Sunrise, FL) is an adjustable-diameter stent retriever that is being tested in an investigational device exemption clinical trial, Treatment with Intent to Generate Reperfusion (TIGER). The retriever is available in three lengths with corresponding adjustable diameters; however, a single device cannot be used for multiple thrombectomy attempts. A clicker-based expansion mechanism allows incremental expansion of the retriever and step-wise increase in radial force to the parent vessel diameter. The clicker mechanism is used to expand the stent retriever until it is apposed with the vessel walls. Rest of the procedure is similar to a mechanical thrombectomy performed with a conventional stent retriever and is demonstrated in the video.

Case Description:

We present a case of a 59-year-old woman who presented with left-upper extremity weakness, facial droop, and hemineglect. Perfusion imaging demonstrated increased time-to-peak. Angiography showed right internal carotid artery terminus occlusion. The patient underwent successful mechanical thrombectomy (Thrombolysis in Cerebral Infarction 2b reperfusion) using the Tigertriever and was discharged home without any perioperative complications.

Conclusion:

An adjustable, expandable stent retriever allows operator to size the stent retriever to match the target artery diameter. The expandable design of stent retriever has potential implications for distal vessel occlusion mechanical thrombectomy.

Sovereign immunity and its implications for neurosurgery

The proportion of neurosurgeons facing a malpractice suit each year is highest among all medical and surgical specialties. It is critical for neurosurgeons to understand local malpractice laws because they vary among states. Sovereign immunity, as described in the 11th constitutional amendment, provides absolute immunity to states from being sued by their residents and by other states. A state may waive its sovereign immunity, however, and substitute itself as the defendant in place of a state-employed physician in the court of law. This means that a physician working for a state-funded hospital may not be liable to a malpractice suit. Further provisions of the law allow the state not to pay indemnity beyond a certain limit, which discourages plaintiff attorneys from pursuing indemnity charges against physicians working for state-funded institutions. In this review, the authors describe the concept of sovereign immunity and its implications for the practice of neurosurgery.

Treatment of Carotid Ophthalmic Aneurysm With Woven EndoBridge (WEB SL): 2-Dimensional Operative Video

Wide-necked cerebral aneurysms often require complex treatment strategies for optimal treatment. As the surgeon's arsenal continues to expand, consideration of all potential applications of available devices is important. The Woven EndoBridge (WEB) device (MicroVention-Terumo, Aliso Viejo, California) capitalizes on flow disruption to promote thrombosis and is Food and Drug Administration (FDA) approved for saccular wide-necked bifurcation aneurysms located at the middle cerebral artery bifurcation, internal carotid artery (ICA) terminus, anterior communicating artery complex, and basilar apex. In this video, we demonstrate an off-label use of the WEB to treat a wide-necked type II1 ophthalmic artery aneurysm, highlighting the importance of correct device sizing. The patient is a 74-yr-old woman with a family history of aneurysms. Her aneurysm was found incidentally after a minor trauma. Observation and various treatment options were considered. The patient preferred to avoid open surgical intervention and dual antiplatelet therapy. Endoluminal flow diversion for types II and III ophthalmic artery aneurysms has relatively low occlusion rates and a higher incidence of visual field deficits.1 A WEB device can be an excellent alternative to treat these aneurysms. A biaxial system was used to selectively catheterize the supraclinoid internal carotid artery and then the aneurysm, and optimal flow diversion was achieved. The patient did well and was discharged home the next day on aspirin alone. Six-month angiography showed near-occlusion of the aneurysm and ophthalmic artery patency. The neck remnant will be followed up with repeat angiography in 6 mo. The patient gave informed consent for the procedure and video recording. Institutional review board approval was deemed unnecessary. Video ©University at Buffalo Neurosurgery, 2019. With permission.

Measurement of instant flow reserve to quantify functional flow limitation across stenosis in intracranial atherosclerotic disease

Angiographic stenosis may not be an accurate reflection of physiological flow limitation. Measurement of instant flow reserve (IFR) to quantify functional flow limitation across stenosis may be valuable in identifying lesions causing significant flow limitation. A case of left middle cerebral artery atherosclerotic disease is presented. Because medical therapy had failed, endovascular revascularization was chosen. In this video 1, IFR measurement to guide submaximal balloon angioplasty with a 1.5×9 mm non-compliant Mini-Trek balloon (Abbott) is demonstrated. Pressure gradient across the middle cerebral artery-M1 stenosis was measured with a Volcano pressure wire (Philips) before and after submaximal balloon angioplasty. An excellent radiographic result and flow improvement into the severely stenosed segment were achieved, with an IFR increase from 0.23 to 0.89. The degree of corresponding stenosis changed from 85% to 30%. No periprocedural complication was observed. IFR can help to identify lesions requiring treatment in select patients and prevent the tendency to overtreat a lesion that is not physiologically significant.

Safety and feasibility of ulnar artery access for neuroangiography and neurointervention: a case series

BACKGROUND

Radial access has become popular among neurointerventionalists because it has favorable risk profiles compared with femoral access. Difficulties in accessing or navigating the radial artery have been viewed as a reason to convert to femoral access, but ulnar artery access may prevent complications associated with transfemoral procedures.

OBJECTIVE

To evaluate the safety and feasibility of ulnar access for neurointerventions and diagnostic neuroangiographic procedures.

METHODS

Consecutive patients who underwent diagnostic angiography or neurointerventional procedures via ulnar access between July 1, 2019 and April 15, 2020 were included. Data recorded were demographics, procedure indication, devices, technique, and complications. Descriptive analysis was performed.

RESULTS

Ulnar artery access was obtained for 21 procedures in 18 patients (mean age 70.3±7.8 years; nine men). Procedures included 13 diagnostic angiograms and eight neurointerventions (3 left middle meningeal artery embolization, 1 of which was aborted; 2 carotid artery stenting; 2 angioplasty; 1 mechanical thrombectomy for in-stent thrombosis). A right-sided approach with ultrasound guidance was used for all cases except one. Indications included small caliber radial artery (n=9), radial artery occlusion (n=10), and radial artery preservation for potential bypass (n=2). A 5-French slender sheath was used for diagnostic angiography; a 6-French slender sheath was used for neurointerventions. No case required conversion to femoral access. Two patients had minor hematomas after the procedure; one other had ulnar artery occlusion on 30-day ultrasonography.

CONCLUSION

Ulnar access is safe and feasible for diagnostic and interventional neuroangiographic procedures. It provides a useful alternative to radial access, potentially avoiding complications associated with femoral access.

Transradial access for flow diversion of intracranial aneurysms: Case series

BACKGROUND

Transradial access for neurointerventions offers advantages of fewer access-site complications, reduced procedure time, and greater patient comfort over transfemoral access. Data about transradial access for flow diversion are limited. We share our early experience with transradial access for flow diversion in a relatively large case series.

METHODS

Consecutive patients who underwent Pipeline embolization device (Medtronic) deployment via transradial access were included in the study, irrespective of location and laterality of the intracranial aneurysm. The cases were performed between July 2016 and October 2019. Demographics, aneurysm characteristics, and procedure-related details (including catheter systems used) were recorded and statistically evaluated.

RESULTS

Thirty-five transradial flow diversion procedures were attempted in 32 patients, of which 33 procedures were successful. In two cases involving left common carotid artery and internal carotid artery access, guide catheter herniation into the aortic arch led to abandonment of transradial access in favor of transfemoral access. The most common aneurysm locations in the transradial access procedures were the posterior communicating artery (n = 7), ophthalmic artery (n = 7), and superior hypophyseal artery (n = 7). Most transradial access procedures (66.7%) were performed using a biaxial catheter system. 6-French Benchmark (Penumbra) and Phenom 27 (Medtronic) were the most commonly utilized guide- and microcatheters, respectively. One patient had intraprocedural subarachnoid hemorrhage. No access-site complications occurred.

CONCLUSION

This study demonstrates safety and feasibility of transradial access for Pipeline embolization device deployment and shows the versatility of this approach for different catheter systems. Tortuosity and acute angulation of the left common carotid artery and internal carotid artery were associated with approach failure.

Septal dysembryoplastic neuroepithelial tumor: a comprehensive clinical, imaging, histopathologic, and molecular analysis

BACKGROUND

Dysembryoplastic neuroepithelial tumors (DNETs) are uncommon neural tumors presenting most often in children and young adults and associated with intractable seizures. Rare midline neoplasms with similar histological features to those found in DNETs have been described near the septum pellucidum and termed "DNET-like neoplasms of the septum pellucidum." Due to their rarity, these tumors have been described in just a few reports and their genetic alterations sought only in small series.

METHODS

We collected 20 of these tumors for a comprehensive study of their clinical, radiological, and pathological features. RNA sequencing or targeted DNA sequencing was undertaken on 18 tumors, and genome-wide DNA methylation profiling was possible with 11 tumors. Published cases (n = 22) were also reviewed for comparative purposes.

RESULTS

The commonest presenting symptoms and signs were related to raised intracranial pressure; 40% of cases required cerebrospinal fluid diversion. Epilepsy was seen in approximately one third of cases. All patients had an indolent disease course, despite metastasis within the neuraxis in a few cases. Radiologically, the septum verum/septal nuclei were involved in all cases and are the proposed site of origin for septal DNET (sDNET). Septal DNET showed a high frequency (~80%) of mutations of platelet derived growth factor receptor A (PDGFRA), and alterations in fibroblast growth factor receptor 1 (FGFR1) and neurofibromatosis type 1 (NF1) were also identified. In a genomic DNA methylation analysis alongside other neural tumors, sDNETs formed a separate molecular group.

CONCLUSIONS

Genetic alterations that are different from those of cerebral DNETs and a distinct methylome profile support the proposal that sDNET is a distinct disease entity.

Transradial middle meningeal artery embolization for chronic subdural hematoma using Onyx: case series

Background

Middle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation.

Methods

Data for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018–2019) were analyzed from a single-center, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed.

Results

Forty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) TRA embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of TRA conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity Index (>5). Symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. At mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009).

Conclusion

Transradial Onyx MMA embolization under conscious sedation is safe and effective for CSDH treatment. TRA may be especially useful in elderly patients with numerous comorbidities.

The Reproducibility of Cerebrovascular Randomized Controlled Trials

BACKGROUND

Numerous randomized controlled trials (RCTs) relevant to the cerebrovascular field have been performed. The fragility index was recently developed to complement the P value and measure the robustness and reproducibility of clinical findings of RCTs.

OBJECTIVE

In this study, we evaluate the fragility index for key surgical and endovascular cerebrovascular RCTs and propose a novel RCT classification system based on the fragility index.

METHODS

Cerebrovascular RCTs reported between 2000 and 2018 were reviewed. Six key areas were specifically targeted in relation to stroke, carotid stenosis, cerebral aneurysms, and subarachnoid hemorrhage. The correlation between fragility index, number of patients lost to follow-up, and fragility quotient were evaluated to propose a classification system for the robustness of the studies.

RESULTS

A total of 20 RCTs that reported significant differences between both study groups in terms of the primary outcome were included. The median fragility index for the trials was 5.5. An additional 30 randomly selected RCTs were added to propose a classification system with high reliability. The difference between the number of patients lost to follow-up and fragility index inversely correlated with the fragility quotient and was used to divide the robustness of the RCTs into 3 classes reflecting the reproducibility of the trial.

CONCLUSIONS

Neurosurgeons and neurointerventionalists should exercise caution with interpreting the results of cerebrovascular RCTs, especially when the sample size and events numbers are small and there is a high number of patients who were lost to follow-up, as quantitatively identified using the proposed classification system.

Impact of endovascular reperfusion on low National Institutes of Health Stroke Scale score large-vessel occlusion stroke

INTRODUCTION

Effectiveness of mechanical thrombectomy for mild-deficit stroke due to large-vessel occlusion is controversial. We present a single-center consecutive case series on thrombectomy for large-vessel occlusion mild stroke. We evaluated various thrombectomy parameters to better understand disagreement in the literature.

METHODS

Data from a retrospective cohort of large-vessel occlusion mild stroke patients (National Institutes of Health Stroke Scale <6) treated with mechanical thrombectomy over 6 years and 2 months were analyzed. Patients were divided into 2 groups: successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b or 3) and failed reperfusion (modified Thrombolysis in Cerebral Infarction 0,1, or 2a). Ninety-day modified Rankin Scale in-hospital mortality, and symptomatic hemorrhage rates were compared between groups. Multivariate logistic regression was performed to evaluate reperfusion status as a predictor of 90-day favorable (modified Rankin Scale 0-2) and excellent (modified Rankin Scale 0-1) outcomes.

RESULTS

We identified 61 patients with large-vessel occlusion mild stroke who underwent thrombectomy. Reperfusion was successful in 49 patients and a failure in 12. The successful group exhibited significantly higher rates of favorable outcome (83.7% vs. 25.0%; p < 0.001) and excellent outcome (69.4% vs.16.7%; p = 0.002) at 90 days. In-hospital mortality was significantly higher in the failure group (41.7% vs.10.2%; p = 0.019). Multivariate logistic regression identified successful reperfusion as a significant predictor (p = 0.001) of 90-day favorable outcome.

CONCLUSION

Reperfusion success was significantly associated with improved functional outcomes in large-vessel occlusion mild stroke mechanical thrombectomy. Future studies should consider reperfusion rates when evaluating the effectiveness of thrombectomy against that of medical management in these patients.

Cerebral Revascularization for Moyamoya Syndrome Associated with Sickle Cell Disease: A Systematic Review of the Literature on the Role of Extracranial-Intracranial Bypass in Treating Neurologic Manifestations of Pediatric Patients with Sickle Cell Disease

Moyamoya syndrome (MMS) in patients with sickle cell disease (SCD) accentuates the risk of recurrent strokes. Chronic transfusion therapy (CTT) is an excellent option for preventing recurrent strokes in most patients with SCD. In SCD with MMS, CTT may fail as a long-term solution. Cerebral revascularization, in the form of extracranial-intracranial bypass, has been shown to prevent recurrent strokes in this cohort. We review the evolution of this paradigm shift in the management of SCD-associated MMS. A systematic review, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol, was conducted. Our primary objectives were 1) to study the evolution of cerebral revascularization techniques in management of MMS in SCD and 2) to analyze the impact of neurosurgical intervention in this high-risk population. Four patients with SCD-associated MMS, who underwent indirect cerebral revascularization at our institute were retrospectively reviewed. A summary of 13 articles chronicling the advent and subsequent evolution of cerebral revascularization as a viable treatment strategy for stroke prevention in SCD-associated MMS is presented. The literature review suggests that early detection and surgical intervention (in addition to CTT) could significantly reduce stroke recurrence and improve neurocognitive outcome. Our short series of 4 patients also had a good outcome and no recurrence of strokes postoperatively. The literature emphasizes the use of a traditional standardized protocol for early identification (transcranial Dopplers, selective magnetic resonance angiography, and CTT). Early treatment and screening that involves early magnetic resonance angiography and referral to neurosurgery for revascularization may be considered for this high-risk population.

Gender disparities in academic rank achievement in neurosurgery: a critical assessment

OBJECTIVE

The objective of this study was to evaluate whether there are disparities in academic rank and promotion between men and women neurosurgeons.

METHODS

The profiles of faculty members from 50 academic neurosurgery programs were reviewed to identify years in practice, number of PubMed-indexed publications, Doctor of Philosophy (PhD) attainment, and academic rank. The number of publications at each academic rank was compared between men and women after controlling for years in practice by using a negative binomial regression model. The relationship between gender and each academic rank was also determined after controlling for clustering at the institutional level, years in practice, and number of publications.

RESULTS

Of 841 faculty members identified, 761 (90%) were men (p = 0.0001). Women represented 12% of the assistant and associate professors but only 4% of the full professors. Men and women did not differ in terms of the percentage holding a PhD, years in practice, or number of publications at any academic rank. After controlling for years in practice and clustering at the facility level, the authors found that men were twice as likely as women to be named full professor (OR 2.2, 95% CI 1.09-4.44, p = 0.03). However, when institution, years in practice, PhD attainment, h-index, and number of publications were considered, men and women were equally likely to attain full professorship (OR 0.9, 95% CI 0.42-1.93).

CONCLUSIONS

Data analysis of the top neurosurgery programs suggests that although there are fewer women than men holding positions in academic neurosurgery, faculty rank attainment does not seem to be influenced by gender.

Posterior Interhemispheric Precuneal Approach: Fundamental Principles and Case Illustration: 3-Dimensional Operative Video

Peritrigonal lesions are deeply seated and are surrounded by critical neurovascular structures. Traditional transcortical approaches carry the risk of damage to important surrounding white matter tracts. In this regard, a posterior interhemispheric approach gives a more direct and less invasive route and therefore is a reasonable alternative to transcortical approaches. The 3-dimensional video includes illustrations and animations showing the anatomy of the white matter tracts around the trigone and explains the physiological basis of posterior interhemispheric precuneal approach to this complex region. This also includes a 3-dimensional operative video of the same approach in a 50-yr-old male patient with left periatrial lesion describing surgical techniques and nuances.

An informed written consent has been obtained from the patient.

One-piece Orbitozygomatic Craniotomy for Resection of Rathke's Cleft Cyst: Operative Video

Objective  The video stars orbitozygomatic resection of Rathke's cleft cyst with suprasellar extension in a 37-year-old male patient presenting with severe headaches and bitemporal hemianopia. Clinical and radiological characteristics along with surgical technique (positioning, bony opening, surgical dissection and debulking, closure), histopathology, and postoperative course are described.

Methods  Preoperative MRI demonstrated a noncontrast-enhancing cystic lesion in the sella with suprasellar extension causing compression of both optic nerves. A one-piece orbitozygomatic craniotomy was performed. The tumor was encountered in the interoptic space. First, the cyst was decompressed and fluid appearing like motor oil was aspirated. Both optic nerves were decompressed and dissected free from the cyst wall. Intraoperatively, the most challenging aspect was separating the tumor from surrounding vascular structures, including bilateral A1 arteries and the left carotid bifurcation. A combination of sharp and blunt dissection was utilized to free the tumor from adhesions to critical neurovascular structures. Once freed, the suprasellar aspect of the tumor was mobilized into the operative cavity and debulked. Finally, the sellar component of the tumor was removed all the way down to the sellar floor. Postoperative MRI demonstrated decompressed bilateral optic nerves with an intact pituitary stalk with preservation of normal pituitary gland. Histopathology identified pathognomonic features consistent with diagnosis of Rathke's cleft cyst, including flattened ciliated epithelium and presence of Rathke's cleft remnants.

Results  Postoperatively, bilateral improvement in vision was noted with transient diabetes insipidus. Patient was discharged home on postoperative day 4.

Conclusion  A one-piece orbitozygomatic craniotomy is an effective and safe strategy for resection of Rathke's cleft cysts with suprasellar extension.

The link to the video can be found at: https://youtu.be/-Yqtcd2gLSs .

Delayed Spinal Arachnoiditis Following Aneurysmal Subarachnoid Hemorrhage: A Case Report

Spinal arachnoiditis (SA) is a rare and delayed complication of aneurysmal subarachnoid hemorrhage (aSAH). We present a case of delayed SA associated with thoracic and lumbar arachnoid cysts in a patient with aSAH secondary to a ruptured vertebral artery aneurysm. The patient underwent a thoracic laminectomy for decompression of the spinal cord, lysis of arachnoid adhesions, and fenestration of an arachnoid cyst. We present the pathogenesis, diagnosis, treatment, and management of spinal arachnoiditis as a rare complication of aSAH. 

Role of Stereotactic Radiosurgery in the Management of Multiple Metastases in the Region of the Motor Cortex: Long-term Survival in Three Cases

The management of patients with multiple brain metastases, in contrast to those with solitary metastases, continues to evolve. Recent evidence suggests that aggressive microsurgical and radiosurgical management of patients with multiple brain metastases may lead to improved survival and quality of life. The three cases discussed in this report are examples of patients with multiple brain metastases who had excellent outcomes following treatment with microsurgical and radiosurgical approaches. A common feature of each patient is the presence of multiple metastases in the region of the motor cortex. The rationale for this selection is to demonstrate that aggressive management can have a favorable outcome despite the presence of multiple metastases in eloquent regions of the brain.