An Anatomic Assessment of the Intercavernous Sinuses and Review of the Literature.

Introduction 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 intercavernous sinus (AIS), posterior intercavernous sinus (PIS), and inferior intercavernous sinus (IIS). We performed a cadaveric study to better understand these structures. Methods Colored latex was injected into the arterial and venous trees of 17 cadaveric heads. Dissections assessed the presence and dimensions of the AIS, PIS, and IIS. In an additional three specimens, the sellar contents were subjected to histological analysis. Results Of the 20 total specimens, 13 (65%) demonstrated the gross presence of all three sinuses. In six specimens (30%), only the AIS and PIS could be identified, and in one specimen, only an AIS and IIS were identified. An AIS was identified in all 20 (100%) specimens, PIS in 18 (88%), and an IIS in 14 (70%). In two specimens (10%), the AIS covered the entire face of the sella. Dimensions of the AIS averaged 1.7 × 11.7 × 2.8 mm, PIS averaged 1.5 × 10.8 × 1.7 mm, and IIS averaged 8.7 × 11.8 × 1.0 mm when present. Conclusion All examined specimens demonstrated the presence of an AIS, and most had a PIS. The presence of an IIS was more variable. Preoperative awareness of these sinuses is helpful in planning transsphenoidal surgery to minimize the risk of bleeding.

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.

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.

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.

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.

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.

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.

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.

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;14/5/neurintsurg-2021-017985/V1F1V1Video 1.

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.

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.

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;14/1/neurintsurg-2021-017400/V1F1V1Video 1.

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.

Artificial Intelligence for Large-Vessel Occlusion Stroke: A Systematic Review.

BACKGROUND: Optimal outcomes after large-vessel occlusion (LVO) stroke are highly dependent on prompt diagnosis, effective communication, and treatment, making LVO an attractive avenue for the application of artificial intelligence (AI), specifically machine learning (ML). Our objective is to conduct a systematic review to describe existing AI applications for LVO strokes, delineate its effectiveness, and identify areas for future AI applications in stroke treatment and prognostication. METHODS: A systematic review was conducted by searching the PubMed, Embase, and Scopus databases. After deduplication, studies were screened by title and abstract. Full-text studies were screened for final inclusion based on prespecified inclusion and exclusion criteria. Relevant data were extracted from each study. RESULTS: Of 11,512 resultant articles, 40 were included. Of 30 studies with reported ML algorithms, the most commonly used ML algorithms were convolutional neural networks in 10 (33.3%), support vector machines in 10 (33.0%), and random forests in 9 (30.0%). Studies examining triage favored direct transport to a stroke center and predicted improved outcomes. ML techniques proved vastly accurate in identifying LVO on computed tomography. Applications of AI to patient selection for thrombectomy are lacking, although some studies determine individual patient eligibility for endovascular treatment with high accuracy. ML algorithms have reasonable accuracy in predicting clinical and angiographic outcomes and associated factors. CONCLUSIONS: AI has shown promise in the diagnosis and triage of patients with acute stroke. However, the role of AI in the management and prognostication remains limited and warrants further research to help in decision support.

Revascularization Outcome Prediction for A Direct Aspiration-First Pass Technique (ADAPT) from Pre-Treatment Imaging and Machine Learning.

A direct aspiration-first pass technique (ADAPT) has recently gained popularity for the treatment of large vessel ischemic stroke. Here, we sought to create a machine learning-based model that uses pre-treatment imaging metrics to predict successful outcomes for ADAPT in middle cerebral artery (MCA) stroke cases. In 119 MCA strokes treated by ADAPT, we calculated four imaging parameters-clot length, perviousness, distance from the internal carotid artery (ICA) and angle of interaction (AOI) between clot/catheter. We determined treatment success by first pass effect (FPE), and performed univariate analyses. We further built and validated multivariate machine learning models in a random train-test split (75%:25%) of our data. To test model stability, we repeated the machine learning procedure over 100 randomizations, and reported the average performances. Our results show that perviousness (p = 0.002) and AOI (p = 0.031) were significantly higher and clot length (p = 0.007) was significantly lower in ADAPT cases with FPE. A logistic regression model achieved the highest accuracy (74.2%) in the testing cohort, with an AUC = 0.769. The models had similar performance over the 100 train-test randomizations (average testing AUC = 0.768 ± 0.026). This study provides feasibility of multivariate imaging-based predictors for stroke treatment outcome. Such models may help operators select the most adequate thrombectomy approach.

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.

Neurosurgery Billing and Reimbursement in 2021.

Practicing neurosurgery in 2021 requires a detailed knowledge of the vocabulary and mechanisms for coding and reimbursement, which should include general knowledge at the global level and fluency at the provider level. It is specifically of interest for the neurosurgeon to understand conceptually the nuances of hospital reimbursement. That knowledge is especially germane as more neurosurgeons become hospital employees. Here we provide an overview of the mechanics of coding. We illustrate the formula to generate physician reimbursement through the current relative value unit structure. We also seek to explain hospital-level reimbursement through the diagnosis-related group structure. Finally, we expand about different and ancillary income streams available to neurosurgeons and provide a realistic assessment including the opportunities and challenges of those entities.

The Medical Legal Environment in Neurosurgery: An Informative Overview of the Stages of Litigation and Distinct Challenges.

Medical malpractice litigation is something that every neurosurgeon encounters in his or her career and causes significant strife to amateur physicians attempting to navigate the medicolegal process. Neurosurgery in particular is one of the highest risk specialties for litigation. This calls to order the importance of a clear understanding of the medicolegal proceedings that may follow after a complaint has been filed. This report describes the steps to be taken by the physician in the instance that litigation is expected or considered a possibility. We describe the elements that comprise a medical malpractice claim, details of the lawsuit process including hospital peer review and expert witness selection, and how to communicate appropriately with the patients and their families in an empathetic way. It is imperative to gain an appropriate understanding of the entirety of the malpractice claim process to ease the anxiety of litigation for the physician and decrease the amount of avoidable complications.

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.

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.