The Influence of Body Mass Index on Outcomes in Patients Undergoing Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion: Institutional Experience and Meta-analysis.

BACKGROUND: An obesity paradox, whereby patients with higher body mass index (BMI) experience improved outcomes, has been described for ischemic stroke. It is unclear whether this applies to patients undergoing mechanical thrombectomy (MT) for large vessel occlusion (LVO). METHODS: Mechanical thrombectomies for anterior circulation LVO between 2015 and 2021 at a single institution were reviewed. Multivariable logistic regressions were used to determine the association between BMI and favorable functional outcome (90-day modified Rankin Scale 0-2), intracranial hemorrhage, and malignant middle cerebral infarction. A systematic review was performed to identify studies reporting the effect of BMI on outcomes among patients receiving MT for LVO. The data from the systematic review were combined with the institutional data by using a random effects model. RESULTS: The institutional cohort comprised 390 patients with a median BMI of 27 kg/m2. Most patients were obese [36.7% (BMI ≥ 30 kg/m2)], followed by overweight [30.5% (BMI ≥ 25 and < 30 kg/m2)], normal [27.9% (BMI ≥ 18.5 and < 25 kg/m2)], and underweight [4.9% (BMI < 18.5 kg/m2)]. As a continuous variable, BMI was not associated with any of the outcomes. When analyzing BMI ordinally, obesity was associated with lower odds of favorable 90-day modified Rankin Scale (odds ratio 0.42, 95% confidence interval 0.20-0.86). The systematic review identified three eligible studies comprising 1,348 patients for a total of 1,738 patients. In the random effects model, there was no association between obesity and favorable outcome (odds ratio 0.89, 95% confidence interval 0.63-1.24). CONCLUSIONS: Obesity is not associated with favorable outcomes in patients undergoing MT for LVO.

Development and Internal Validation of Machine Learning Models to Predict Mortality and Disability After Mechanical Thrombectomy for Acute Anterior Circulation Large Vessel Occlusion.

OBJECTIVE: Mechanical thrombectomy (MT) improves outcomes in patients with LVO but many still experience mortality or severe disability. We sought to develop machine learning (ML) models that predict 90-day outcomes after MT for LVO. METHODS: Consecutive patients who underwent MT for LVO between 2015-2021 at a Comprehensive Stroke Center were reviewed. Outcomes included 90-day favorable functional status (mRS 0-2), severe disability (mRS 4-6), and mortality. ML models were trained for each outcome using prethrombectomy data (pre) and with thrombectomy data (post). RESULTS: Three hundred and fifty seven patients met the inclusion criteria. After model screening and hyperparameter tuning the top performing ML model for each outcome and timepoint was random forest (RF). Using only prethrombectomy features, the AUCs for the RFpre models were 0.73 (95% CI 0.62-0.85) for favorable functional status, 0.77 (95% CI 0.65-0.86) for severe disability, and 0.78 (95% CI 0.64-0.88) for mortality. All of these were better than a standard statistical model except for favorable functional status. Each RF model outperformed Pre, SPAN-100, THRIVE, and HIAT scores (P < 0.0001 for all). The most predictive features were premorbid mRS, age, and NIHSS. Incorporating MT data, the AUCs for the RFpost models were 0.80 (95% CI 0.67-0.90) for favorable functional status, 0.82 (95% CI 0.69-0.91) for severe disability, and 0.71 (95% CI 0.55-0.84) for mortality. CONCLUSIONS: RF models accurately predicted 90-day outcomes after MT and performed better than standard statistical and clinical prediction models.

The influence of pre-reperfusion blood pressure on outcomes following mechanical thrombectomy for anterior circulation large vessel occlusion.

BACKGROUND: We evaluated how systolic blood pressure (SBP) and mean arterial pressure (MAP) parameters between presentation and reperfusion influence functional status and intracranial hemorrhage (ICH). METHODS: All patients who underwent MT for LVO at a single institution were reviewed. Independent variables included SBP and MAP measurements obtained on presentation, between presentation and reperfusion (pre-reperfusion), and between groin puncture and reperfusion (thrombectomy). Mean, minimum, maximum, and standard deviations (SD) for SBP and MAP were calculated. Outcomes included 90-day favorable functional status, radiographic ICH (rICH), and symptomatic ICH (sICH). RESULTS: 305 patients were included. Higher pre-reperfusion SBPmax was associated with rICH (OR 1.41, 95% CI 1.08-1.85) and sICH (OR 1.84, 95% CI 1.26-2.72). Higher SBPSD was also associated with rICH (OR 1.38, 95% CI 1.06-1.81) and sICH (OR 1.59, 95% CI 1.12-2.26). Greater SBPmax (OR 0.64, 95% CI 0.47-0.86), MAPmax (OR 0.72, 95% CI 0.52-0.97), SBPSD (OR 0.63, 95% CI 0.46-0.86), and MAPSD (0.63, 95% CI 0.45-0.84) during thrombectomy were associated with lower odds of 90-day favorable functional status. In a subgroup analysis, these associations were primarily limited to patients with intact collateral circulation. Optimal SBPmax cutoffs for predicting rICH were 171 (pre-reperfusion) and 179 mmHg (thrombectomy). Cutoffs for predicting sICH were 178 (pre-reperfusion) and 174 mmHg (thrombectomy). CONCLUSION: Greater maximum BP and variability in BP during the pre-reperfusion period are associated with unfavorable functional status and ICH after MT for anterior circulation LVO.

Machine learning prediction of malignant middle cerebral artery infarction after mechanical thrombectomy for anterior circulation large vessel occlusion.

OBJECTIVE: Prediction of malignant middle cerebral artery infarction (MMI) could identify patients for early intervention. We trained and internally validated a ML model that predicts MMI following mechanical thrombectomy (MT) for ACLVO. METHODS: All patients who underwent MT for ACLVO between 2015 - 2021 at a single institution were reviewed. Data was divided into 80% training and 20% test sets. 10 models were evaluated on the training set. The top 3 models underwent hyperparameter tuning using grid search with nested 5-fold CV to optimize the area under the receiver operating curve (AUROC). Tuned models were evaluated on the test set and compared to logistic regression. RESULTS: A total of 381 patients met the inclusion criteria. There were 50 (13.1%) patients who developed MMI. Out of the 10 ML models screened on the training set, the top 3 performing were neural network (median AUROC 0.78, IQR 0.72 - 0.83), support vector machine ([SVM] median AUROC 0.77, IQR 0.72 - 0.83), and random forest (median AUROC 0.75, IQR 0.68 - 0.81). On the test set, random forest (median AUROC 0.78, IQR 0.73 - 0.83) and neural network (median AUROC 0.78, IQR 0.73 - 0.83) were the top performing models, followed by SVM (median AUROC 0.77, IQR 0.70 - 0.83). These scores were significantly better than those for logistic regression (AUROC 0.72, IQR 0.66 - 0.78), individual risk factors, and the Malignant Brain Edema score (p < 0.001 for all). CONCLUSION: ML models predicted MMI with good discriminative ability. They outperformed standard statistical techniques and individual risk factors.

Endovascular embolization for the treatment of epistaxis: Systematic review and meta-analysis.

BACKGROUND: Endovascular embolization (EE) is a treatment option for epistaxis refractory to first-line interventions. Data regarding embolization is limited to small case series and a meta-analysis has not been performed. METHODS: PubMed, Scopus, and EMBASE were used to identify studies that reported outcomes for at least 10 patients undergoing EE for epistaxis. Outcomes included procedural success, rebleeding, and complications. Pooled rates for each outcome were obtained with random effects models. RESULTS: A total of 44 studies comprising 1664 patients met the inclusion criteria. The mean age ranged from 28.1 to 67 years and there were 28.4% females. The pooled procedural success rate was 87% (95% CI 83.9-89.6, I2 = 53%). Age (OR 0.95, 95% CI 0.91-1) and hereditary hemorrhagic telangiectasia ([HHT], OR 0.97, 95% CI 0.96-0.99) were associated with decreased odds of success. The pooled rebleeding rate was 16.4% (95% CI 13.6-19.6, I2 = 48%), and HHT was associated with greater odds of rebleeding (OR 1.02, 95% CI 1-1.03). The pooled overall complication rate was 14.4% (95% CI 9.8-20.6, I2 = 85.8%). The pooled rates of stroke and vision loss were 2.1% (95% CI 1.5-3.1, I2 = 1.5%) and 1.8% (95% CI 1.2-2.6, I2 = 0%), respectively. CONCLUSION: EE for epistaxis has a high rate of procedural success. Interventionalists should be aware of the risk for rebleeding, especially among patients with HHT.

Percutaneous embolization of sinus pericranii.

Sinus pericranii is a rare vascular anomaly involving a venous sinus that drains into a subgaleal collection of veins through an emissary vein. Data regarding presentation, management, and outcomes are limited to case reports and small case series. There are no technical videos detailing the technique for percutaneous embolization. We present the case of a child with an enlarging, symptomatic accessory type sinus pericranii with connection to the torcula, who underwent percutaneous embolization after unsuccessful transvenous embolization. Embolization was performed with 3.4 cc Onyx-34 under live fluoroscopy and serial control superior sagittal sinus venograms . Significant reduction of flow into the sinus pericranii was achieved and the lesion had nearly completely resolved at the 3-week follow-up. Percutaneous embolization of the sinus pericranii is a reasonable alternative to transvenous embolization, but additional data are needed to determine the optimal treatment. The technical details and practical considerations discussed here may help neurointerventionalists adopt this treatment. The video also includes references 1-4 which are relevant to this topic. neurintsurg;15/8/828/V1F1V1Video 1Case presentation and technique for percutaneous embolization of sinus pericranii.

Outcomes After Endovascular Treatment of Direct Carotid Cavernous Fistulas: Systematic Review and Meta-Analysis.

BACKGROUND: Direct carotid cavernous fistulas (dCCF) involve pathologic shunting from the internal carotid artery into the cavernous sinus. We systematically reviewed the methods and outcomes of endovascular therapy for dCCF. METHODS: PubMed, Scopus, and EMBASE were used to identify studies that reported outcomes for patients undergoing embolization of dCCF. Outcomes included rates of occlusion, complications, symptom improvement, and recurrence. Pooled rates for each outcome were obtained with random effects models. The influence of embolization method on outcomes was assessed with meta-regressions. RESULTS: There were 16 studies comprising 270 patients. The mean age was 39.6 years, there were 36.3% females, and the mean follow-up was 19.7 months. Coils were the most common method of embolization (69.3%), followed by Onyx (31.1%), covered stent (22.2%), N-butyl cyanoacrylate (6.7%), and flow diversion (4.8%). The pooled overall occlusion rate was 92.1% (95% confidence interval [CI], 86.3-95.6; I2 = 29.2%). The pooled complication rate was 10.9% (95% CI, 7.3-16; I2 = 0%). Use of coils were associated with a slightly lower odds of overall complications (odds ratio, 0.98; 95% CI, 0.97-0.99) and cranial nerve palsy (odds ratio, 0.98; 95% CI, 0.97-0.99). The pooled fistula recurrence rate was 8.3% (95% CI, 4.3-15.4; I2 = 30.9%). CONCLUSIONS: Endovascular therapy for dCCF is associated with high occlusion and low complication rates. Recurrence is not uncommon, highlighting the need for close follow-up.

Embolization of a Dural Arteriovenous Fistula Using Transcranial Middle Meningeal Artery Access: 2-Dimensional Operative Video.

The transcranial approach for direct middle meningeal artery (MMA) access to embolize dural arteriovenous fistulas (dAVF) has been described, but limited information regarding the setup, equipment, and technique is available. We present the details of this hybrid approach in the setting of a ruptured Cognard grade IV tentorial dAVF (Video 1). The patient was an adult female who presented with nausea, vomiting, and dizziness and was found to have a cerebellar hemorrhage. Catheter angiography revealed a tentorial dAVF fed by bilateral middle meningeal, left posterior meningeal, and left occipital arteries. Attempted transarterial embolizations through each of these were unsuccessful. The left MMA was a primary source of supply, but distal microcatheter placement was not possible due to proximal tortuosity. Therefore transcranial MMA access distal to this tortuosity was pursued. The MMA was localized using roadmap angiography and a temporal craniectomy was completed over the artery. A 4-French sheath was placed, and super selective angiography was performed, demonstrating the fistula. A microcatheter was navigated to the fistula and it was embolized with Onyx. Postoperative angiogram demonstrated fistula occlusion. The patient remained at her neurologic baseline and was discharged home. Transcranial MMA access is a useful technique to overcome tortuosity that cannot be navigated with traditional endovascular techniques.

Outcomes after endovascular embolization for the treatment of nasal and oropharyngeal hemorrhage: safety, efficacy, and rebleeding.

BACKGROUND: Intractable nasal and oropharyngeal hemorrhage may be treated with endovascular embolization, but limited data are available. We sought to evaluate the efficacy, safety, and factors associated with rebleeding. METHODS: A retrospective analysis of consecutive embolizations for nasal and oropharyngeal hemorrhage over a 10-year period at a single institution was performed. Outcomes included procedural success (defined as cessation of hemorrhage in the immediate postoperative period), rebleeding requiring an additional intervention, and procedural complications. RESULTS: A total of 47 embolizations on 39 patients were included. The mean age was 60 years (standard deviation 16.1), 23.1% of patients were women, and 21 (53.8%) patients had a previously diagnosed head/neck malignancy. Bleeding sites were the nose in 20 patients and oropharynx in 21 (two patients presented with both nasal and oral bleeding). Immediate procedural success was achieved in 45 (95.7%) embolizations. Rebleeding requiring an additional intervention occurred after 11 (23.4%) embolizations at a median of one day after the procedure. In the multivariate analysis, preoperative hypotension (odds ratio 4.78, 95% confidence interval 1.04-24.61) and the use of coils (odds ratio 6.09, 95% confidence interval 1.24-46.69) were associated with rebleeding requiring repeat intervention. Complications included two watershed strokes that were anticipated due to occlusion of the internal carotid artery. CONCLUSIONS: In our experience endovascular embolization was a safe and effective treatment option for stopping oral and nasal hemorrhage. However, rebleeding was present after 23.4% of treatments and was associated with preoperative hypotension and the use of coils. Further study in a large multi-institutional cohort is warranted.

Trends in mechanical thrombectomy and decompressive hemicraniectomy for stroke: A multicenter study.

BACKGROUND AND PURPOSE: Acute ischemic stroke has increasingly become a procedural disease following the demonstrated benefit of mechanical thrombectomy (MT) for emergent large vessel occlusion (ELVO) on clinical outcomes and tissue salvage in randomized trials. Given these data and anecdotal experience of decreased numbers of decompressive hemicraniectomies (DHCs) performed for malignant cerebral edema, we sought to correlate the numbers of strokes, thrombectomies, and DHCs performed over the timeline of the 2013 failed thrombolysis/thrombectomy trials, to the 2015 modern randomized MT trials, to post-DAWN and DEFUSE 3. MATERIALS AND METHODS: This is a multicenter retrospective compilation of patients who presented with ELVO in 11 US high-volume comprehensive stroke centers. Rates of tissue plasminogen activator (tPA), thrombectomy, and DHC were determined by current procedural terminology code, and specificity to acute ischemic stroke confirmed by each institution. Endpoints included the incidence of stroke, thrombectomy, and DHC and rates of change over time. RESULTS: Between 2013 and 2018, there were 55,247 stroke admissions across 11 participating centers. Of these, 6145 received tPA, 4122 underwent thrombectomy, and 662 patients underwent hemicraniectomy. The trajectories of procedure rates over time were modeled and there was a significant change in MT rate (p = 0.002) without a concomitant change in the total number of stroke admissions, tPA administration rate, or rate of DHC. CONCLUSIONS: This real-world study confirms an increase in thrombectomy performed for ELVO while demonstrating stable rates of stroke admission, tPA administration and DHC. Unlike prior studies, increasing thrombectomy rates were not associated with decreased utilization of hemicraniectomy.

Comparison of the Safety, Efficacy, and Procedural Characteristics Associated with Proximal and Distal Radial Access for Diagnostic Cerebral Angiography.

OBJECTIVES: Radial access is an increasingly popular approach for performing cerebral angiography. There are two sites for radial artery puncture: proximal transradial access (pTRA) in the wrist and distal transradial access (dTRA) in the snuffbox. These approaches have not been directly compared. MATERIALS AND METHODS: Consecutive diagnostic cerebral angiograms performed at a single institution were retrospectively reviewed. Outcomes included fluoroscopy time, radiation dose, contrast volume, time to obtain access, procedure duration, and time to discharge home. Success rates as well as minor and major complication rates associated with each approach were also compared. Multivariate linear regression models were used to determine the relationship between access site and outcomes while adjusting for covariates. RESULTS: A total of 287 angiograms on 244 patients met the inclusion criteria. pTRA was associated with shorter fluoroscopy time (ß -2.54, 95% CI -4.18 - -0.9, p = 0.003) and lower radiation dose (ß -242.89, 95% CI -351.55 - -134.24, p < 0.001), but not contrast volume. Time to obtain access, procedure duration, and time to discharge home were similar between approaches. A total of 10 minor complications occurred with similar rates for each approach (8 for dTRA, 2 for pTRA, p = 0.168) and there were no major complications. The conversion rate to femoral access was low (1.05% overall) and did not differ with approach. CONCLUSION: dTRA and pTRA are associated with similarly high rates of safety and efficacy. Procedure duration, time to obtain access, and time to discharge did not differ between approaches.

Initial experience of subcutaneous nitroglycerin for distal transradial access in neurointerventions.

BACKGROUND: Transradial access (TRA) for diagnostic and interventional neuroendovascular procedures has gained significant popularity in recent years due to its improved safety profile and appeal to patients compared with transfemoral access. However, risks of TRA include hand ischemia in cases of poor ulnar collateral circulation and inability to cannulate the radial artery due to its relatively small diameter. By accessing the radial artery distal to the superficial palmar arch where ulnar collateral blood flow arises, in the anatomic snuffbox, the risk of hand ischemia is theoretically eliminated. The use of subcutaneous nitroglycerin and lidocaine to improve rates of success in radial artery access has been reported in the cardiac literature, however, has yet to be described for neurointerventional procedures. We discuss our technique and report our initial experience using subcutaneous nitroglycerin and lidocaine cocktail for access to the distal transradial artery in a variety of neuroendovascular procedures. METHODS: A retrospective review of our institution's database of neurointerventional and diagnostic procedures performed using dTRA was conducted, and 64 patients were identified between February and December 2020. Patient demographics, clinical data, procedural details, and radiographic information were collected and analyzed. RESULTS: A total of 64 patients underwent neurointerventional procedures using the subcutaneous injection for dTRA access. The procedures performed included diagnostic cerebral angiograms (n = 47), stent and balloon assisted aneurysm coiling (n = 5), flow diversion (n = 2), intra-saccular device placement (n = 1), mechanical thrombectomy (n = 1), tumor embolization (n = 1), middle meningeal artery embolization (n = 2), extracranial carotid stent placement (n = 2), and arteriovenous malformation embolization (n = 3). While no complications of hand ischemia were appreciated, the access site conversion rate was 3.1%; 2 cases required a switch to femoral artery access due to proximal vessel tortuosity and aortic anatomical variations, and not due to access site complication. Furthermore, on repeat angiograms by the same proceduralist, distal TRA (dTRA) was successful in 100% of the cases. CONCLUSION: dTRA using subcutaneous nitroglycerin and lidocaine is a safe and effective method for neurointerventional and diagnostic procedures.

Transition from Proximal to Distal Radial Access for Diagnostic Cerebral Angiography: Learning Curve Analysis.

BACKGROUND: Distal transradial access (dTRA) has several advantages compared with proximal transradial access (pTRA) for cerebral angiography. The learning curve for transitioning from pTRA to dTRA has not been described. METHODS: Retrospective analysis of the first 75 diagnostic cerebral angiograms performed with dTRA by a single operator was performed. Outcomes included time for sheath insertion, sheath to first vessel time, procedure duration, fluoroscopy time, radiation dose, and contrast volume. Their associations with procedure number were evaluated with multivariate linear regressions, segmented linear regression, and locally weighted regression (LOESS). RESULTS: The mean age of patients was 56.1 years and 61.3% were female. Seventy-four of 75 angiograms were successfully completed with dTRA. There were 3 minor and no major complications. After adjusting for covariates, sheath to first vessel time (ß = -0.50, P < 0.001) and procedure duration (ß = -0.26, P = 0.002) were associated with procedure number. Time for sheath insertion, fluoroscopy time, radiation dose, and contrast volume were not associated with procedure number. Segmented linear regression identified break-points of 33 for sheath to first vessel time and 11 for procedure duration, which corresponded to the procedure number after which these outcomes trended down. LOESS models for time to sheath placement, procedure duration, fluoroscopy time, and radiation dose predicted minimum values between procedures 40-50. CONCLUSIONS: Transitioning from pTRA to dTRA for diagnostic cerebral angiography is feasible and safe. The learning curve is overcome between procedures 11 and 33, and further refinement in performance occurs through procedures 40-50.

Cervical spine reoperation rates and hospital resource utilization after initial surgery for degenerative cervical spine disease in 12,338 patients in Washington State.

OBJECTIVE: Patients undergoing surgery for degenerative cervical spine disease may require future surgery for disease progression. We investigated factors related to the rate of additional cervical spine surgery, the associated length of stay, and hospital charges. METHODS: The was a longitudinal retrospective cohort study using Washington state's 1998 to 2002 state inpatient databases and International Classification of Diseases-Ninth Revision-Clinical Modification (ICD-9) codes to analyze patients undergoing degenerative cervical spine surgery. Multivariate Poisson regression to identify patient and surgical factors associated with reoperation for degenerative cervical spine disease was used. Multivariate linear regressions to identify factors associated with length of stay and hospital charges adjusted for age, sex, year of surgery, primary diagnosis, payment type, discharge status, and comorbidities were also used. RESULTS: A total of 12,338 patients underwent initial cervical spine surgeries from 1998 to 2002; the mean follow-up duration was 2.3 years, and 688 patients (5.6%) underwent a reoperation (2.5% per year). Higher reoperation rates were independently associated with younger patients (P < 0.001) and a primary diagnosis of disc herniation with myelopathy (P = 0.011). Ventral surgery (P < 0.001) and fusion (P < 0.001) were both associated with lower rates of reoperation; however, a high correlation (Spearman's rho = 0.82; P < 0.001) made it impossible to determine which factor was dominant. Longer length of stay was independently associated with nonventral approaches (+1.0 day; P < 0.001) and fusion surgery (+0.8 day; P < 0.001). Greater hospital charges were independently associated with nonventral approaches (+$2900; P < 0.001) and fusion surgery (+$9600; P < 0.001). CONCLUSION: Patients undergoing surgery for degenerative cervical spine disease undergo reoperations at the rate of 2.5% per year. An initial ventral approach and/or fusion seem to be associated with lower reoperation rates. An initial nonventral approach and fusion were more expensive.