The Influence of Coagulopathy on Radiographic and Clinical Outcomes in Patients Undergoing Middle Meningeal Artery Embolization as Standalone Treatment for Non-acute Subdural Hematomas

Middle meningeal artery embolization (MMAE) is emerging as a safe and effective standalone intervention for non-acute subdural hematomas (NASHs); however, the risk of hematoma recurrence after MMAE in coagulopathic patients is unclear. To characterize the impact of coagulopathy on treatment outcomes, we analyzed a multi-institutional database of patients who underwent standalone MMAE as treatment for NASH. We classified 537 patients who underwent MMAE as a standalone intervention between 2019 and 2023 by coagulopathy status. Coagulopathy was defined as use of anticoagulation/antiplatelet agents or pre-operative thrombocytopenia (platelets <100,000/μL). Demographics, pre-procedural characteristics, in-hospital course, and patient outcomes were collected. Thrombocytopenia, aspirin use, antiplatelet agent use, and anticoagulant use were assessed using univariate and multivariate analyses to identify any characteristics associated with the need for rescue surgical intervention, mortality, adverse events, and modified Rankin Scale score at 90-day follow-up. Propensity score-matched cohorts by coagulopathy status with matching covariates adjusting for risk factors implicated in surgical recurrence were evaluated by univariate and multivariate analyses. Minimal differences in pre-operative characteristics between patients with and those without coagulopathy were observed. On unmatched and matched analyses, patients with coagulopathy had higher rates of requiring subsequent surgery than those without (unmatched: 9.9% vs. 4.3%; matched: 12.6% vs. 4.6%; both p < 0.05). On matched multivariable analysis, patients with coagulopathy had an increased odds ratio (OR) of requiring surgical rescue (OR 3.95; 95% confidence interval [CI] 1.68-9.30; p < 0.01). Antiplatelet agent use (ticagrelor, prasugrel, or clopidogrel) was also predictive of surgical rescue (OR 4.38; 95% CI 1.51-12.72; p = 0.01), and patients with thrombocytopenia had significantly increased odds of in-hospital mortality (OR 5.16; 95% CI 2.38-11.20; p < 0.01). There were no differences in follow-up radiographic and other clinical outcomes in patients with and those without coagulopathy. Patients with coagulopathy undergoing standalone MMAE for treatment of NASH may have greater risk of requiring surgical rescue (particularly in patients using antiplatelet agents), and in-hospital mortality (in thrombocytopenic patients).

Transvenous embolization of noncavernous dural arteriovenous fistulas (dAVFs): A systematic review and meta-analysis

BACKGROUND

Intracranial dural arteriovenous fistulas (dAVFs) are abnormal connections between arteries and veins within the dura mater. Various treatment modalities, such as surgical ligation, endovascular intervention, and radiosurgery, aim to close the fistulous connection. Although transvenous embolization (TVE) is the preferred method for carotid-cavernous fistulas, its description and outcomes for noncavernous dAVFs vary. This has prompted a systematic review and meta-analysis to comprehensively assess the effectiveness of TVE in treating noncavernous dAVFs, addressing variations in outcomes and techniques.

METHODS

We searched PubMed and Embase, spanning from the earliest records to December 2022, to identify pertinent English-language articles detailing the utilization of TVE. We focused on specific procedural details, outcomes, and complications in patients older than 18 years. The data collected and analyzed comprised the sample size, number of fistulas, publication specifics, presenting symptoms, fistula grades, and pooled rates of embolizations, outcomes, follow-up information, and complications.

RESULTS

From a total of 565 screened articles, 15 retrospective articles encompassing 166 patients spanning across seven countries met the inclusion criteria. Their Newcastle-Ottawa scores ranged from 6 to 8. Intraprocedural complication rate was 10% (95% confidence interval [CI] = 5.9-17.1) and in-hospital postprocedural complication rate was 5.4% (95% CI = 2.8-10.6). Prevalence of in-hospital mortality was 5.5% (95% CI = 2.9-10.6). Complication rate during follow-up was 8.6% (95% CI = 4.7-15.7) with fistula rupture occurring in 5.5% (95% CI = 2.6-11.6) of patients. Complete obliteration rate at final angiographic follow-up was 94.9% (95% CI = 90.3-99.9). Symptoms improved in 95% (95% CI = 89.8-100) of patients at final follow-up.

CONCLUSION

To our knowledge, we present the first meta-analysis assessing obliteration rates, outcomes, and complications of TVE for dAVFs. Our analysis highlights the higher (>90%) complete obliteration rates. Large prospective multicenter studies are needed to better define the utility of TVE for noncavernous dAVFs.

General Versus Nongeneral Anesthesia for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score Matched Study

BACKGROUND AND OBJECTIVES

The choice of anesthesia type (general anesthesia [GA] vs nongeneral anesthesia [non-GA]) in middle meningeal artery embolization (MMAE) procedures for chronic subdural hematomas (cSDH) differs between institutions and left to care team discretion given lack of standard guidelines. We compare the outcomes of GA vs non-GA in MMAE.

METHODS

Consecutive patients receiving MMAE for cSDH at 14 North American centers (2018-2023) were included. Clinical, cSDH characteristics, and technical/clinical outcomes were compared between the GA/non-GA groups. Using propensity score matching (PSM), patients were matched controlling for age, baseline modified Rankin Scale, concurrent/prior surgery, hematoma thickness/midline shift, and baseline antiplatelet/anticoagulation. The primary end points included surgical rescue and radiographic success rates (≥50% reduction in maximum hematoma thickness with minimum 2 weeks of imaging). Secondary end points included technical feasibility, procedural complications, and functional outcomes.

RESULTS

Seven hundred seventy-eight patients (median age 73 years, 73.2% male patients) underwent 956 MMAE procedures, 667 (70.4%) were non-GA and 280 were GA (29.6%). After running 1:3 PSM algorithm, this resulted in 153 and 296 in the GA and non-GA groups, respectively. There were no baseline/procedural differences between the groups except radial access more significantly used in the non-GA group (P = .001). There was no difference between the groups in procedural technical feasibility, complications rate, length of stay, surgical rescue rates, or favorable functional outcome at the last follow-up. Subsequent 1:1 sensitivity PSM retained the same results. Bilateral MMAE procedures were more performed under non-GA group (75.8% vs 67.2%; P = .01); no differences were noted in clinical/radiographic outcomes between bilateral vs unilateral MMAE, except for longer procedure duration in the bilateral group (median 73 minutes [IQR 48.3-100] vs 54 minutes [39-75]; P < .0001). Another PSM analysis comparing GA vs non-GA in patients undergoing stand-alone MMAE retained similar associations.

CONCLUSION

We found no significant differences in radiological improvement/clinical outcomes between GA and non-GA for MMAE.

Transcarotid Arterial Revascularization of Symptomatic Internal Carotid Artery Disease: A Systematic Review and Study-Level Meta-Analysis

BACKGROUND

Transcarotid artery revascularization (TCAR) is an interventional therapy for symptomatic internal carotid artery disease. Currently, the utilization of TCAR is contentious due to limited evidence. In this study, we evaluate the safety and efficacy of TCAR in patients with symptomatic internal carotid artery disease compared with carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

A systematic review was conducted, spanning from January 2000 to February 2023, encompassing studies that used TCAR for the treatment of symptomatic internal carotid artery disease. The primary outcomes included a 30-day stroke or transient ischemic attack, myocardial infarction, and mortality. Secondary outcomes comprised cranial nerve injury and major bleeding. Pooled odds ratios (ORs) for each outcome were calculated to compare TCAR with CEA and CAS. Furthermore, subgroup analyses were performed based on age and degree of stenosis. In addition, a sensitivity analysis was conducted by excluding the vascular quality initiative registry population.

RESULTS

A total of 7 studies involving 24 246 patients were analyzed. Within this patient cohort, 4771 individuals underwent TCAR, 12 350 underwent CEA, and 7125 patients underwent CAS. Compared with CAS, TCAR was associated with a similar rate of stroke or transient ischemic attack (OR, 0.77 [95% CI, 0.33-1.82]) and myocardial infarction (OR, 1.29 [95% CI, 0.83-2.01]) but lower mortality (OR, 0.42 [95% CI, 0.22-0.81]). Compared with CEA, TCAR was associated with a higher rate of stroke or transient ischemic attack (OR, 1.26 [95% CI, 1.03-1.54]) but similar rates of myocardial infarction (OR, 0.9 [95% CI, 0.64-1.38]) and mortality (OR, 1.35 [95% CI, 0.87-2.10]).

CONCLUSIONS

Although CEA has traditionally been considered superior to stenting for symptomatic carotid stenosis, TCAR may have some advantages over CAS. Prospective randomized trials comparing the 3 modalities are needed.

MicroCT and Histological Analysis of Clot Composition in Acute Ischemic Stroke : A Comparative Study of MT-Retrieved Clots and Clot Analogs

PURPOSE

Assessing clot composition on prethrombectomy computed tomography (CT) imaging may help in stroke treatment planning. In this study we seek to use microCT imaging of fabricated blood clots to understand the relationship between CT radiographic signals and the biological makeup.

METHODS

Clots (n = 10) retrieved by mechanical thrombectomy (MT) were collected, and 6 clot analogs of varying RBC composition were made. We performed paired microCT and histological image analysis of all 16 clots using a ScanCo microCT 100 (4.9 µm resolution) and standard H&E staining (imaged at 40×). From these data types, first order statistic (FOS) radiomics were computed from microCT, and percent composition of RBCs (%RBC) was computed from histology. Polynomial and linear regression (LR) were used to build statistical models based on retrieved thrombus microCT and %RBC that were evaluated for their ability to predict the %RBC of clot analogs from mean HU. Correlation analyses of microCT FOS with composition were completed for both retrieved clots and analogs.

RESULTS

The LR model fits relating MT-retrieved clot %RBC with mean (R2 = 0.625, p = 0.006) and standard deviation (R2 = 0.564, p < 0.05) in HUs on microCT were significant. Similarly, LR models relating analog histological %RBC to analog protocol %RBC (R2 = 0.915, p = 0.003) and mean HUs on microCT (R2 = 0.872, p = 0.007) were also significant. When the LR model built using MT-retrieved clots was used to predict analog %RBC from mean HUs, significant correlation was observed between predictions and actual histological %RBC (R2 = 0.852, p = 0.009). For retrieved clots, significant correlations were observed for energy and total energy with %RBC and %FP (|R| > 0.7, q < 0.01). Analogs further demonstrated significant correlation between FOS energy, total energy, variance and %WBC (|R| > 0.9, q < 0.01).

CONCLUSION

MicroCT can be used to build models that predict AIS clot composition from routine CT parameters and help us to better understand radiomic signatures associated with clot composition and first pass outcomes. In future work, such observations can be used to better infer clot composition and inform thrombectomy prognostics from pretreatment CTs.

A propensity score-matched comparative study of balloon guide catheters versus conventional guide catheters for concurrent mechanical thrombectomy with carotid stenting in tandem strokes: comparison of first pass effect, symptomatic intracranial hemorrhage, and 90-day functional outcomes

BACKGROUND

Extensive clot burden in tandem strokes accounts for poor mechanical thrombectomy (MT) outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in MT and carotid artery stenting.

OBJECTIVE

In view of this potential benefit, to investigate the safety and effectiveness of proximal flow arrest using a BGC during concurrent MT and carotid revascularization for tandem stroke treatment in a comparative, propensity score-matched (PSM) study.

METHODS

Patients with a tandem stroke identified from our endovascular database were dichotomized into groups treated with BGCs versus conventional guide catheters. One-to-one PSM adjustment for baseline demographics and treatment selection bias using nearest-neighbor matching was performed. Patient demographics, presentation characteristics, and procedural details were recorded. Outcomes assessed were final modified Thrombolysis in Cerebral Infarction (mTICI) grade, periprocedural symptomatic intracranial hemorrhage (sICH) rate, in-hospital mortality, and 90-day modified Rankin Scale (mRS) score. Mann-Whitney U test and multivariate logistic regression were performed to compare procedural parameters and clinical outcomes.

RESULTS

Concurrent carotid revascularization (stenting with/without angioplasty) and MT was performed in 125 cases (BGC: 85; no BGC: 40). After PSM (40 patients/group), the BGC group had a significantly shorter procedure duration (77.9 vs 61.5 min; OR=0.996; P=0.006), lower discharge National Institutes of Health Stroke Scale score (8.0 vs 11.0; OR=0.987; P=0.042), and higher odds of 90-day mRS 0-2 score (52.3% vs 27.5%; OR=0.34; P=0.040). On multivariate regression, the BGC group had a significantly higher first pass effect rate (mTICI 2b or 3)(OR=1.115, 95% CI 1.015 to 1.432; P=0.013) and lower periprocedural sICH rate (OR=0.615, 95% CI 0.406 to 0.932; P=0.025). No difference in in-hospital mortality was observed (OR=1.591, 95% CI 0.976 to 2.593; P=0.067).

CONCLUSION

BGCs used for concurrent MT-carotid revascularization with flow arrest were safe and resulted in superior clinical and angiographic outcomes in patients with a tandem stroke.

Association of area deprivation index (ADI) with demographics and postoperative outcomes in pediatric brain tumor patients

PURPOSE

Although social determinants of health (SDOH) have been associated with adverse surgical outcomes, cumulative effects of multiple SDOH have never been studied. The area deprivation index (ADI) assesses cumulative impact of SDOH factors on outcomes. We analyzed the relationship between ADI percentile and postoperative outcomes in pediatric patients diagnosed with brain tumors.

METHODS

A retrospective, observational study was conducted on our consecutive series of pediatric brain tumor patients presenting between January 1, 1999, and May 31, 2022. Demographics and outcomes were collected, identifying SDOH factors influencing outcomes found in the literature. ADI percentiles were identified based on patient addresses, and patients were stratified into more (ADI 0-72%) and less (ADI 73-100%) disadvantaged cohorts. Univariate and multivariate logistic regression analyses were completed for demographics and outcomes.

RESULTS

A total of 272 patients were included. Demographics occurring frequently in the more disadvantaged group were Black race (13.1% vs. 2.8%; P = .003), public insurance (51.5% vs. 27.5%; P < .001), lower median household income ($64,689 ± $19,254 vs. $46,976 ± $13,751; P < .001), and higher WHO grade lesions (15[11.5%] grade III and 8[6.2%] grade IV vs. 8[5.6%] grade III and 5[3.5%] grade IV; P = .11). The more disadvantaged group required adjunctive chemotherapy (25.4% vs. 12.05%; P = .007) or radiation therapy (23.9% vs. 12.7%; P = .03) more frequently and had significantly greater odds of needing adjunctive chemotherapy (odds ratio [OR], 1.11; confidence interval [CI], 1.01-1.22; P = .03) in a multivariate model, which also identified higher WHO tumor grades at presentation (OR, 1.20; CI, 1.14-1.27; P < .001).

CONCLUSION

These findings are promising for use of ADI to represent potential SDOH disadvantages that pediatric patients may face throughout treatment. Future studies should pursue large multicenter collaborations to validate these findings.

Social Determinants of Health and Associations With Outcomes in Pediatric Patients With Brain Tumors

BACKGROUND AND OBJECTIVES

Social determinants of health (SDOH) are nonmedical factors that affect health outcomes. Limited investigation has been completed on the potential association of these factors to adverse outcomes in pediatric populations. In this study, the authors aimed to analyze the effects of SDOH disparities and their relationship with outcomes after brain tumor resection or biopsy in children.

METHODS

The authors retrospectively reviewed the records of their center's pediatric patients with brain tumor. Black race, public insurance, median household income, and distance to hospital were the investigated SDOH factors. Univariate analysis was completed between number of SDOH factors and patient demographics. Multivariate linear regression models were created to identify coassociated determinants and outcomes.

RESULTS

A total of 272 patients were identified and included in the final analysis. Among these patients, 81 (29.8%) had no SDOH disparities, 103 (37.9%) had 1, 71 (26.1%) had 2, and 17 (6.2%) had 3. An increased number of SDOH disparities was associated with increased percentage of missed appointments ( P = .002) and emergency room visits ( P = .004). Univariate analysis demonstrated increased missed appointments ( P = .01), number of postoperative imaging ( P = .005), and number of emergency room visits ( P = .003). In multivariate analysis, decreased median household income was independently associated with increased length of hospital stay ( P = .02).

CONCLUSION

The SDOH disparities are prevalent and impactful in this vulnerable population. This study demonstrates the need for a shift in research focus toward identifying the full extent of the impact of these factors on postoperative outcomes in pediatric patients with brain tumor.

Mechanical thrombectomy in low Alberta stroke program early CT score (ASPECTS) in hyperacute stroke-a systematic review and meta-analysis

OBJECTIVE

Major randomized controlled trials of mechanical thrombectomy (MT) for acute ischemic stroke (AIS) failed to include a substantial number of patients presenting with low baseline Alberta Stroke Program Early CT Score (ASPECTS:0-5). Patients experiencing hyperacute strokes (last known well ≤ 6 h) can potentially benefit most from MT. We conducted a systematic review and meta-analysis to report presentation severity and radiographic and clinical outcomes for hyperacute stroke patients presenting with low-ASPECTS.

METHODS

Our comprehensive literature search of PubMed, Embase, and Cochrane databases up to August 31, 2022 included articles reporting patients presenting hyperacutely who underwent MT for anterior circulation large vessel occlusion AIS with an ASPECTS ≤ 5 on baseline imaging. Pooled averages were calculated for age and presenting National Institutes of Health Stroke Scale (NIHSS). Fixed- and random-effects meta-analyses for weighted estimation of overall rates were performed. Forest plots were generated for proportions and estimated overall outcome rates.

RESULTS

18 studies (1958 patients) were included (mean age = 64.1 years; presenting NIHSS = 18.4). Final modified thrombolysis in cerebral infarction 2b-3 grade was achieved in 76.4%, with symptomatic intracranial hemorrhage in 12.1%. Good (modified Rankin Scale [mRS] 0-2) and ambulatory (mRS 0-3) 3-month outcomes were achieved by 27.4 and 46.7%, respectively; 90-day mortality was 26.4%.

CONCLUSION

MT in low-ASPECTS hyperacute stroke patients may result in ambulatory clinical outcomes with acceptable hemorrhage risk. Recanalization rates achieved were similar to those in patients presenting with ASPECTS ≥ 6; this did not fully translate to better clinical outcomes.

ADVANCES IN KNOWLEDGE

MT should be considered for hyperacute strokes with low presenting ASPECTS.

Cerebral emboli detection and autonomous neuromonitoring using robotic transcranial Doppler with artificial intelligence for transcatheter aortic valve replacement with and without embolic protection devices: a pilot study

BACKGROUND

Periprocedural ischemic stroke remains a serious complication in patients undergoing transcatheter aortic valve replacement (TAVR). We used a novel robotic transcranial Doppler (TCD) system equipped with artificial intelligence (AI) for real-time continuous intraoperative neuromonitoring during TAVR to establish the safety and potential validity of this tool in detecting cerebral emboli, report the quantity and distribution of high intensity transient signals (HITS) with and without cerebral protection, and correlate HITS occurrence with various procedural steps.

METHODS

Consecutive patients undergoing TAVR procedures during which the robotic system was used between October 2021 and May 2022 were prospectively enrolled in this pilot study. The robotic TCD system included autonomous adjustment of the TCD probes and AI-assisted post-processing of HITS and other cerebral flow parameters. Basic demographics and procedural details were recorded. Continuous variables were analyzed by a two-sample Mann-Whitney t-test and categorical variables by a χ2 or Fisher test.

RESULTS

Thirty-one patients were prospectively enrolled (mean age 79.9±7.6 years; 16 men (51.6%)). Mean aortic valve stenotic area was 0.7 cm2 and mean aortic-ventricular gradient was 43 mmHg (IQR 31.5-50 mmHg). Cerebral protection was used in 16 cases (51.6%). Significantly fewer emboli were observed in the protection group than in the non-protection group (mean 470.38 vs 693.33; p=0.01). Emboli counts during valve positioning and implantation were significantly different in the protection and non-protection groups (mean 249.92 and 387.5, respectively; p=0.01). One (4%) transient ischemic attack occurred post-procedurally in the non-protection group.

CONCLUSION

We describe a novel real-time intraoperative neuromonitoring tool used in patients undergoing TAVR. Significantly fewer HITS were detected with protection. Valve positioning-implantation was the most significant stage for intraprocedural HITS.

Standalone middle meningeal artery embolization versus middle meningeal artery embolization with concurrent surgical evacuation for chronic subdural hematomas: a multicenter propensity score matched analysis of clinical and radiographic outcomes

BACKGROUND

Middle meningeal artery embolization (MMAE) has emerged as a promising therapy for chronic subdural hematomas (cSDHs). The efficacy of standalone MMAE compared with MMAE with concurrent surgery is largely unknown.

METHODS

cSDH patients who underwent successful MMAE from 14 high volume centers with at least 30 days of follow-up were included. Clinical and radiographic variables were recorded and used to perform propensity score matching (PSM) of patients treated with standalone MMAE or MMAE with concurrent surgery. Multivariable logistic regression models were used for additional covariate adjustments. The primary outcome was recurrence requiring surgical rescue, and the secondary outcome was radiographic failure defined as <50% reduction of cSDH thickness.

RESULTS

722 MMAE procedures in 588 cSDH patients were identified. After PSM, 230 MMAE procedures remained (115 in each group). Median age was 73 years, 22.6% of patients were receiving anticoagulation medication, and 47.9% had no preoperative functional disability. Median midline shift was 4 mm and cSDH thickness was 16 mm, representing modestly sized cSDHs. Standalone MMAE and MMAE with surgery resulted in similar rates of surgical rescue (7.8% vs 13.0%, respectively, P=0.28; adjusted OR (aOR 0.73 (95% CI 0.20 to 2.40), P=0.60) and radiographic failure (15.5% vs 13.7%, respectively, P=0.84; aOR 1.08 (95% CI 0.37 to 2.19), P=0.88) with a median follow-up duration of 105 days. These results were similar across subgroup analyses and follow-up durations.

CONCLUSIONS

Standalone MMAE led to similar and durable clinical and radiographic outcomes as MMAE combined with surgery in select patients with moderately sized cSDHs and mild clinical disease.

Analysis of craniectomy bone flaps stored in a neurosurgical cryopreservation freezer: microorganism culture results and reimplantation rates

BACKGROUND

Cryopreservation of bone flaps after decompressive craniectomies is a common practice. A frequent complication after bone flap reimplantation is postoperative infection, so culturing of frozen craniectomy bone flaps is a crucial practice that can prevent patient morbidity and mortality. Although many studies report on infection rates after cranioplasty, no study reports on the results of bone flaps stored in a cryopreservation freezer, reimplanted or otherwise. We sought to analyze the flaps in our medical center's bone bank freezer, including microorganism culture results and reimplantation rates of cryopreserved bone flaps.

METHODS

Patients who underwent craniectomy and had bone flaps cryopreserved between January 1, 2016, and July 1, 2022, were included in this retrospective study. Information about bone flap cultures and reimplantation or discard was obtained from a prospectively maintained cryopreservation database. Information including infection rates and mortality was acquired from a retrospective review of patient records. Culture results were obtained for all flaps immediately before cryopreservation and again at the time of reimplantation at the operator's discretion.

RESULTS

There were 148 bone flaps obtained from 145 patients (3 craniectomies were bilateral) stored in our center's freezer. Positive culture results were seen in 79 (53.4%) flaps. The most common microorganism genus was Propionibacterium with 47 positive flaps, 46 (97.9%) of which were P. acnes. Staphylococcus was the second most common with 23 positive flaps, of which 8 (34.8%) tested positive for S. epidermidis. Of the 148 flaps, 25 (16.9%) were reimplanted, 116 (78.4%) were discarded, and 7 (4.7%) are still being stored in the freezer. Postcranioplasty infections were seen in 3 (12%) patients who had flap reimplantation.

CONCLUSIONS

Considering the substantial number of positive cultures and limited reimplantation rate, we have reservations about the logistical efficiency of cryopreservation for flap storage. Future multicenter studies analyzing reimplantation predictors could help to reduce unnecessary freezing and culturing.

Effect of Chronic Anticoagulation on Outcomes of Endovascular Treatment for Unruptured Intracranial Aneurysms-A Propensity-Matched Multicenter Study

BACKGROUND AND OBJECTIVES

Endovascular treatment of unruptured intracranial aneurysms (UIAs) in patients receiving anticoagulant medications has not been well studied. Whether long-term anticoagulation (AC) use affects aneurysmal obliteration rates and treatment-related complications is unclear.

METHODS

Patients with endovascular treatment for UIA from 4 academic centers were identified and divided into AC and non-AC groups. Periprocedural complications, radiographic and clinical outcomes, and retreatment rates were compared between the 2 groups before and after propensity score matching.

RESULTS

The initial cohort consisted of 70 patients in the AC group and 355 in the non-AC group. After one-to-one nearest neighbor propensity matching, 38 pairs of patients were compared for periprocedural complications. The total number of complications were higher in the AC group yet not significant (18.4% vs 5.3%, P = .15). After adding imaging follow-up duration to matched variables, 36 pairs were obtained. There was no significant difference in Raymond-Roy occlusion rate between the 2 groups ( P = .74). However, retreatment rate trended higher in the AC group compared with the non-AC group (22.2% vs 5.6%, P = .09). When clinical follow-up duration was added among matched variables, 26 pairs of cases were obtained for long-term clinical outcomes. There was no significant difference in modified Rankin Scale score between the 2 groups ( P = .61). One-to-many nearest neighbor propensities matched analysis with bigger sample sizes yielded similar results.

CONCLUSION

The use of anticoagulants does not affect occlusion rates or long-term outcomes in endovascular treatment of UIAs. Retreatment rates were higher in the AC group; however, this was not statistically significant.

Early Termination versus Standard Regimen Duration of Dual Antiplatelet Therapy in Intracranial Aneurysm Patients Treated With Pipeline Embolization Device Flex With Shield Technology: Preliminary Experience of 3 U.S. Centers

BACKGROUND

Pipeline Flex Embolization Device with Shield Technology (PED-Shield) is a third-generation flow diverter with reduced thromboembolic potential. However, safety profile and dual antiplatelet therapy (DAPT) recommendations with PED-Shield is not well -established. We aim to assess the safety and complication profile with early termination of DAPT with use of PED-Shield.

METHODS

Databases of 3 high-volume cerebrovascular centers were retrospectively reviewed. We identified patients with unruptured and ruptured intracranial aneurysms treated with PED-Shield. Patient demographics, aneurysm characteristics, complications, and angiographic outcomes were extracted. All patients who had early termination of DAPT, defined as <180 days, as well as standard duration were included.

RESULTS

A total of 37 patients, totaling 37 aneurysms, had early termination of DAPT and 24 patients with 24 aneurysms received standard duration (>180 days) of DAPT. There was no difference in pre-procedural DAPT regimens between the groups (P = 0.503). Following DAPT termination, o1ne major thromboembolic complication was observed in the early termination group while no major or minor thromboembolic or hemorrhagic complication was noted in the standard duration group. Time of angiographic follow-up was not statistically different (P = 0.063) between the early termination (343 days, interquartile range [IQR] 114-371 days) and the standard duration (175 days, IQR 111-224.5 days) groups. There were no statistically significant differences in complete aneurysm occlusion (P = 0.857), residual neck (P = 0.582), and aneurysm remnant (P = 0.352) rates between the groups on angiography.

CONCLUSIONS

Early termination of DAPT proves safe after PED-Shield treatment of intracranial aneurysms with comparable complete occlusion rates.

Expansion and Subsequent Rupture of Carotid Pseudoaneurysm After Tandem Carotid and Middle Cerebral Artery Occlusion Treated With Mechanical Thrombectomy and Carotid Stenting

BACKGROUND AND IMPORTANCE

Extracranial carotid artery pseudoaneurysm is a rare entity with potential etiologies including infection, blunt trauma, postsurgical atherosclerotic disease, and invasive neoplasia. Although the natural history of carotid pseudoaneurysm is difficult to determine because of its rarity, complications such as stroke, rupture, and local mass effect may occur at staggering rates.

CLINICAL PRESENTATION

In this case, a middle-aged man presented with a tandem carotid, middle cerebral artery occlusion that was treated with a carotid stent and mechanical thrombectomy. He returned 3 weeks later with a ruptured carotid pseudoaneurysm that was then treated with a covered stent. He made a full recovery and was neurologically intact on follow-up.

CONCLUSION

This case illustrates a rare potential complication of carotid occlusion and stenting with possible catastrophic consequences. The goal of this report was to educate other clinicians in remaining vigilant in awareness of this complication and provide a framework for potential treatment if and when it occurs.

Mechanical thrombectomy in low Alberta Stroke Program Early Computed Tomographic Score: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Due to their poor natural history and lack in level-I evidence, patients with large vessel occlusion and large core infarcts (Alberta Stroke Program Early Computed Tomographic Score <6) have been excluded from receiving mechanical thrombectomy. This systematic review and meta-analysis seeks to summarize current evidence from published randomized controlled trials to compare the safety and efficacy of mechanical thrombectomy with optimal medical therapy in treating stroke patients with large core infarcts.

METHODS

We searched PubMed and EMBASE for randomized controlled trials investigating the safety and efficacy of mechanical thrombectomy vs optimal medical therapy in patients presenting with large vessel occlusion and large infarcts. Basic demographic and comorbidities were assessed, and clinical outcomes were compared, including modified Rankin scale 0-3, and 0-2 at 3 months, symptomatic intracranial hemorrhage, decompressive hemicortectomy, and 90-day mortality.

RESULTS

Three randomized controlled trials totaling 1011 patients (501 and 510 in the medical management and mechanical thrombectomy arm, respectively) were included. Patients undergoing mechanical thrombectomy had significantly higher odds of achieving better functional outcomes at 3 months: Modified Rankin scale 0-2 (OR = 3.05, 95% CI = 2.101-4.4021, p < 0.0001) and modified Rankin scale 0-3 (OR = 2.20, 95% CI = 1.67-2.89, p < 0.0001) as compared to those receiving optimal medical management. There were no differences between groups in 90-day mortality (OR = 0.93, 95% CI = 0.70-1.23, p = 0.60), symptomatic intracranial hemorrhage (OR = 1.89, 95% = CI 0.95-3.77, p = 0.07) or decompressive hemicraniectomy (OR = 1.25, 95% CI = 0.69-2.25, p = 0.46).

CONCLUSION

Mechanical thrombectomy for patients with large infarcts is associated with improved functional outcomes and a similar safety profile compared to optimal medical management. Ongoing trials will help better refine the target population that benefits the most from treatment.

Mechanical thrombectomy in medium vessel occlusions using the novel aspiration Q catheters: an international multicenter experience

BACKGROUND

Medium vessel occlusions (MeVOs) comprise a large proportion of all stroke events. We performed a multicenter study of MIVI Q catheters, a novel design that optimizes suction forces without an increase in lumen diameter, for the treatment of MeVOs, aiming to evaluate its efficacy and safety.

METHODS

Databases of two US and two UK centers were retrospectively reviewed for MeVO patients (M2-M3, anterior cerebral artery (ACA), or posterior cerebral artery (PCA)) treated with Q catheters. Outcomes were assessed as successful recanalization (modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2b), first pass effect (FPE), and modified FPE (mFPE) as single pass achieving mTICI ≥2c and mTICI≥2b, respectively, and 90 day modified Rankin Scale (mRS) score.

RESULTS

69 patients were included (median age 71 years, IQR 56-82.5; 52.2% men). Median National Institutes of Health Stroke Scale (NIHSS) score at admission was 14, and Alberta Stroke Program Early CT Score (ASPECTS) was 9. Primary (without large vessel occlusion (LVO)) and secondary (with LVO) MeVOs represented 47.8% and 52.2% of cases, respectively. Q catheters used were Q3 (47.8%), Q4 (33.3%), Q5 (10.1%), and Q6 (8.7%). mTICI≥2b was achieved in 92.8% of patients, with FPE in 47.8%, and mFPE in 68.1%. Two (2.9%) intraprocedural complications (symptomatic intracranial hemorrhage) occurred. 50% (27/54) achieved an mRS score of ≤2 at the 90 day follow-up. The median NIHSS at admission was significantly higher in secondary than in primary MeVOs (19.5 vs 12, P=0.009). The rate of mRS ≤2 at 90 days was significantly higher in primary than in secondary MeVOs (77.3% vs 31.3%, P=0.002).

CONCLUSIONS

Treatment of MeVO patients with Q catheters resulted in optimal angiographic and clinical outcomes. Although angiographic results were similar between primary and secondary MeVOs, the former had less severe presenting NIHSS and better outcomes at 90 days than the latter.

Standalone vs. Anterior Cervical Plating for One-to-Two Level Anterior Cervical Discectomy and Fusion (ACDF): A Propensity Score-Matched Comparative Study

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) can be performed with and without supportive anterior cervical plating. Fusion rates, incidence of dysphagia, and repeat surgery are concerns when performing ACDF with or without plating. We aimed to compare procedural success and outcomes between patients treated with and without cervical plating for 1-2 level ACDF.

METHODS

A prospectively maintained database was retrospectively searched for patients who underwent 1-2 level ACDF surgery. Patients were divided into cohorts treated with plating and without (standalone). Propensity score matching (PSM) was performed to eliminate selection bias and control for baseline comorbidities and disease severity. Patient demographics (including age, body mass index, smoking status, diabetes mellitus, osteoporosis), disease presentation (cervical stenosis, degenerative disc disease), and operative details (number of operative levels, cage type used, intraoperative and postoperative complications) were recorded. Outcomes assessed were fusion observed at 3, 6, and 12 months, patient-reported postoperative pain, and any repeat surgeries. Univariate analysis was performed according to data normality and variables for PSM cohorts.

RESULTS

A total of 365 patients were identified (plating=289, standalone=76). After PSM, 130 patients (65 in each group) were included for final analysis. Similar mean operative times (101.3±26.5-standalone; 104.8±32.2-plating; p=0.5) and mean hospital stays (1.2±1.8-standalone; 0.7±0.7-plating; p=0.1) were noted. Twelve-month fusion rates were also similar (84.6%-standalone;89.2%-plating; p=0.6). Repeat surgery rates were equivalent (13.8%-standalone;12.3%-plating; p=0.8).

CONCLUSION

In this propensity score-matched case-control study, we report comparable effectiveness and outcomes of performing 1-2 level ACDF with and without cervical plating.

Evaluating a 3D deep learning pipeline for cerebral vessel and intracranial aneurysm segmentation from computed tomography angiography-digital subtraction angiography image pairs

OBJECTIVE

Computed tomography angiography (CTA) is the most widely used imaging modality for intracranial aneurysm (IA) management, yet it remains inferior to digital subtraction angiography (DSA) for IA detection, particularly of small IAs in the cavernous carotid region. The authors evaluated a deep learning pipeline for segmentation of vessels and IAs from CTA using coregistered, segmented DSA images as ground truth.

METHODS

Using 50 paired CTA-DSA images, the authors trained (n = 27), validated (n = 3), and tested (n = 20) a deep learning model (3D DeepMedic) for cerebrovasculature segmentation from CTA. A landmark-based coregistration algorithm was used for registration and upsampling of CTA images to paired DSA images. Segmented vessels from the DSA were used as the ground truth. Accuracy of the model for vessel segmentation was evaluated using conventional metrics (dice similarity coefficient [DSC]) and vessel segmentation-specific metrics, like connectivity-area-length (CAL). On the test cases (20 IAs), 3 expert raters attempted to detect and segment IAs. For each rater, the authors recorded the rate of IA detection, and for detected IAs, raters segmented and calculated important IA morphology parameters to quantify the differences in IA segmentation by raters to segmentations by DeepMedic. The agreement between raters, DeepMedic, and ground truth was assessed using Krippendorf's alpha.

RESULTS

In testing, the DeepMedic model yielded a CAL of 0.971 ± 0.007 and a DSC of 0.868 ± 0.008. The model prediction delineated all IAs and resulted in average error rates of < 10% for all IA morphometrics. Conversely, average IA detection accuracy by the raters was 0.653 (undetected IAs were present to a significantly greater degree on the ICA, likely due to those in the cavernous region, and were significantly smaller). Error rates for IA morphometrics in rater-segmented cases were significantly higher than in DeepMedic-segmented cases, particularly for neck (p = 0.003) and surface area (p = 0.04). For IA morphology, agreement between the raters was acceptable for most metrics, except for the undulation index (α = 0.36) and the nonsphericity index (α = 0.69). Agreement between DeepMedic and ground truth was consistently higher compared with that between expert raters and ground truth.

CONCLUSIONS

This CTA segmentation network (DeepMedic trained on DSA-segmented vessels) provides a high-fidelity solution for CTA vessel segmentation, particularly for vessels and IAs in the carotid cavernous region.

Use of Novel Automated Active Irrigation With Drainage Versus Passive Drainage Alone for Chronic Subdural Hematoma-A Propensity Score-Matched Comparative Study With Volumetric Analysis

BACKGROUND

Passive drainage post-surgical evacuation of symptomatic chronic subdural hematoma (cSDH) is currently standard of care. High rates of infection, drain occlusion, and recurrence are associated complications.

OBJECTIVE

To explore the use of a novel double-lumen active automated irrigation and aspiration system, IRRAflow (IRRAS), for patients with cSDH and compared procedural and clinical outcomes against passive drainage alone with propensity score matching (PSM) and volumetric analysis.

METHODS

A prospectively maintained database was retrospectively searched for consecutive patients presenting with cSDH. One-to-one PSM of covariates (including baseline comorbidities and presentation hematoma volume) in active and passive irrigation groups was performed to adjust for treatment selection bias. Rates of hematoma clearance, catheter-related occlusion, and infection; number of revisions; and length of hospital stay were recorded.

RESULTS

This study included 55 patients: active continuous irrigation-drainage-21 (21 post-PSM) and passive drainage-34 (21 post-PSM). For PSM groups, a significantly higher rate of hematoma clearance was obtained in the active irrigation-drainage group (0.5 ± 0.4 vs 0.4 ± 0.5 mL/day) and in the passive drainage group; odds ratio (OR) = 1.291 (CI: 1.062-1.570, P = .002) and a significantly lower rate of catheter-related infections (OR = 0.051; CI: 0.004-0.697, P = .039). A nonsignificantly lower hematoma expansion rate at discharge was noted in the active irrigation-drainage group (4.8% vs 23.8%; OR = 0.127; P = .186). No statistical difference in all-cause in-hospital mortality or discharge Glasgow Coma Scale score was observed between groups.

CONCLUSION

Active and automated continuous irrigation plus drainage after cSDH surgical evacuation resulted in faster hematoma clearance and led to favorable clinical outcomes and low complication and revision rates compared with passive irrigation.

Hyperacute stenting and angioplasty for acute extracranial non-tandem internal carotid artery strokes within the first 48 h: A 20-year experience and a systematic review and meta-analysis

BACKGROUND

Acute strokes involving complete, isolated occlusion of the extracranial cervical internal carotid artery (EC-ICA) with no intracranial clot burden account for a minority of stroke cases that are managed variably. Here we present our two-decade experience and a systematic review of endovascular management of acute isolated EC-ICA strokes in the hyperacute phase (<48 h) and attempt to evaluate clinical effectiveness and safety.

METHODS

Our prospectively maintained database was retrospectively searched for patients who presented between January 1, 2003 and December 31, 2022 with acute cervical ICA stroke confirmed on angiography. Only patients who had an isolated 100% occlusion of the cervical ICA segment and attempted acute stenting with/without angioplasty within the first 48 h of time since last known well were included. Demographics, procedural details, and outcomes were recorded. For the systematic review, a search of PubMed and Embase databases was conducted.

RESULTS

Forty-six patients with acute, isolated EC-ICA occlusive stroke were included. Median presenting National Institutes of Health Stroke Scale (NIHSS) score was 8 (interquartile range 3-10) with a perfusion deficit in 78.3% of the 40 cases assessed with computed tomography perfusion imaging. Median time from symptom onset to intra-arterial puncture was 14.4 h. Immediate recanalization was achieved in 82.6% cases. Two cases (4.3%) of symptomatic intracranial hemorrhage (sICH) occurred postprocedure. Outcome measures were stable or improved discharge NIHSS score in 86.9% of cases, functional independence at 90 days (modified Rankin scale score ≤2) in 78.3%, and mortality in 6.5%. The systematic review included 167 patients from four articles. The estimated rate of immediate recanalization was 92.7% (95% confidence interval (CI), 88.77-96.77%), favorable outcome was 62.01% (95% CI, 55.04-69.87%), and sICH was 6.2% (95% CI, 3.41-11.32%).

CONCLUSION

Stenting and angioplasty for acute cervical ICA occlusive strokes during the hyperacute phase can be performed successfully with favorable clinical outcomes and an acceptable recanalization rate.

The first endovascular rat glioma model for pre-clinical evaluation of intra-arterial therapeutics

BACKGROUND

Several translational animal models have been described assessing intra-arterial (IA) treatments for malignant gliomas. We describe the first endovascular animal model that allows testing of IA drug delivery as a first-line treatment, which is difficult to do in actual patients. We report a unique protocol for vascular access and IA delivery in the rat model that, unlike prior reports, does not require direct puncture and opening of proximal cerebrovasculature which carries risk of ischemia in the animal brain post-delivery.

METHODS

Wistar rats underwent left femoral artery catherization with a Balt Magic 1.2F catheter or Marathon Flow directed 1.5F Microcatheter with an Asahi Chikai 0.008 micro-guidewire which was navigated to the left internal carotid artery under x-ray. 25% mannitol was administered to test blood brain barrier breakdown (BBBB). Additional rats were implanted with C6 glioma cells in the left frontal lobe. C6 Glioma-Implanted Rats (C6GRs) were monitored for overall survival and tumor growth. Tumor volumes from MRI images were calculated utilizing 3D slicer. Additional rats underwent femoral artery catheterization with Bevacizumab, carboplatin, or irinotecan injected into the left internal carotid artery to test feasibility and safety.

RESULTS

A successful endovascular access and BBBB protocol was established. BBBB was confirmed with positive Evans blue staining. 10 rats were successfully implanted with C6 gliomas with confirmed growths on MRI. Overall survival was 19.75 ± 2.21 days. 5 rats were utilized for the development of our femoral catheterization protocol and BBBB testing. With regards to IA chemotherapy dosage testing, control rats tolerated targeted 10 mg/kg of bevascizumab, 2.4 mg/kg of carboplatin, and 15 mg/kg of irinotecan IA ICA injections without any complications.

CONCLUSIONS

We present the first endovascular IA rat glioma model that allows selective catheterization of the intracranial vasculature and assessment of IA therapies for gliomas without need for access and sacrifice of proximal cerebrovasculature.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma: Predictors of Clinical and Radiographic Failure from 636 Embolizations

Background Knowledge regarding predictors of clinical and radiographic failures of middle meningeal artery (MMA) embolization (MMAE) treatment for chronic subdural hematoma (CSDH) is limited. Purpose To identify predictors of MMAE treatment failure for CSDH. Materials and Methods In this retrospective study, consecutive patients who underwent MMAE for CSDH from February 2018 to April 2022 at 13 U.S. centers were included. Clinical failure was defined as hematoma reaccumulation and/or neurologic deterioration requiring rescue surgery. Radiographic failure was defined as a maximal hematoma thickness reduction less than 50% at last imaging (minimum 2 weeks of head CT follow-up). Multivariable logistic regression models were constructed to identify independent failure predictors, controlling for age, sex, concurrent surgical evacuation, midline shift, hematoma thickness, and pretreatment baseline antiplatelet and anticoagulation therapy. Results Overall, 530 patients (mean age, 71.9 years ± 12.8 [SD]; 386 men; 106 with bilateral lesions) underwent 636 MMAE procedures. At presentation, the median CSDH thickness was 15 mm and 31.3% (166 of 530) and 21.7% (115 of 530) of patients were receiving antiplatelet and anticoagulation medications, respectively. Clinical failure occurred in 36 of 530 patients (6.8%, over a median follow-up of 4.1 months) and radiographic failure occurred in 26.3% (137 of 522) of procedures. At multivariable analysis, independent predictors of clinical failure were pretreatment anticoagulation therapy (odds ratio [OR], 3.23; P = .007) and an MMA diameter less than 1.5 mm (OR, 2.52; P = .027), while liquid embolic agents were associated with nonfailure (OR, 0.32; P = .011). For radiographic failure, female sex (OR, 0.36; P = .001), concurrent surgical evacuation (OR, 0.43; P = .009), and a longer imaging follow-up time were associated with nonfailure. Conversely, MMA diameter less than 1.5 mm (OR, 1.7; P = .044), midline shift (OR, 1.1; P = .02), and superselective MMA catheterization (without targeting the main MMA trunk) (OR, 2; P = .029) were associated with radiographic failure. Sensitivity analyses retained these associations. Conclusion Multiple independent predictors of failure of MMAE treatment for chronic subdural hematomas were identified, with small diameter (<1.5 mm) being the only factor independently associated with both clinical and radiographic failures. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Chaudhary and Gemmete in this issue.

Pre- and Post-Treatment Factors Associated with Shunt-Dependent Hydrocephalus after Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

INTRODUCTION

Hydrocephalus is a common complication following aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to evaluate novel pre- and postoperative risk factors for shunt- dependent hydrocephalus (SDHC) after aSAH via a systematic review and meta-analysis.

METHODS

A systematic search was conducted using Pubmed and Embase databases for studies pertaining to aSAH and SDHC. Articles were assessed by meta-analysis if the number of risk factors for SDHC were reported by greater than 4 studies and could be extracted separately for patients who did or did not develop SDHC.

RESULTS

37 studies were included, comprising 12,667 aSAH patients (SDHC 2,214 vs. non-SDHC 10,453). In a primary analysis of 15 novel potential risk factors, 8 were identified to be significantly associated with increased prevalence of SDHC after aSAH including high World Federation of Neurological Surgeons (WFNS) grades (odds ratio (OR) 2.43), hypertension (OR 1.33), anterior cerebral artery (ACA) (OR 1.36), middle cerebral artery (MCA) (OR 0.65), and vertebrobasilar artery (VBA) (2.21) involvement, decompressive craniectomy (DC) (OR 3.27), delayed cerebral ischemia (DCI) (OR 1.65), and intracerebral hematoma (ICH) (OR 3.91).

CONCLUSIONS

Several new factors associated with increased odds of developing SDHC following aSAH were found to be significant. By providing evidence-based risk factors for shunt dependency, we describe an identifiable list of pre- and postoperative prognosticators that may influence how surgeons recognize, treat, and manage aSAH patients at high risk for developing SDHC.

Mechanical Thrombectomy versus Best Medical Management for Acute Ischemic Stroke in Elderly Patients: A Cost-Effectiveness Analysis

OBJECTIVE

To determine the cost-effectiveness of mechanical thrombectomy (MT) versus best medical management (BMM) in patients ≥80 years.

METHODS

We performed a systematic literature review to identify comparative studies of MT vs BMM with or without intravenous tissue-type plasminogen activator (IV tPA) in patients ≥80 years. Clinical data including outcomes and mortality categorized as modified Rankin scale (mRS) scores 0-2, 3-5, and 6 were collected from identified studies, and effectiveness scores were assigned to each outcome. Costs associated with stroke outcomes were derived from previous literature, including costs associated with initial and follow-up imaging, hospitalization, physicians/associated personnel, and MT. TreeAge Pro software (Williamstown, MA) was used to construct a cost-effectiveness analysis model of clinical data from studies and costs derived from the literature.

RESULTS

The review identified 1 relevant comparative study. The cost model demonstrated total annual cumulative overall per-patient costs of $30,064.21 for BMM with IV tPA and $21,940.36 for BMM without IV tPA. Overall effectiveness scores were 0.61 and 0.62, respectively. MT had a cumulative total annual per-patient cost of $47,849.54 and an overall effectiveness score of 0.40. The cost-effectiveness ratios of total cumulative patient cost-to-overall outcome effectiveness score for the three treatments were: BMM with IV tPA=$49,285.59, BMM without IV tPA=$35,387.58, and MT=$119,623.85. BMM with or without IV tPA was found to be more cost-effective than MT.

CONCLUSIONS

This study utilized stroke outcomes data for patients ≥80 years to conduct a cost-effectiveness analysis. MT was found to be less cost-effective than BMM with and without IV tPA.

Mechanical thrombectomy versus medical management for acute basilar artery occlusions: A meta-analysis of randomized trials

BACKGROUND

Basilar artery occlusion (BAO) stroke is a catastrophic clinical event that results in significant morbidity and mortality. Whether MT is superior in improving outcomes remains largely inconclusive. We performed a meta-analysis of randomized controlled trials (RCTs) to better understand the efficacy and safety of MT in treating BAO compared to medical management (MM).

METHODS

PubMed and EMBASE were searched to identify RCTs that directly compared the safety and efficacy of MT versus MM for patients with BAO. The primary outcome was modified Rankin scale (mRS) 0-3 at 3 months, and secondary outcome variables included National Institutes of Health Stroke Scale (NIHSS) at 24 hours, mRS 0-2 at 3 months, symptomatic intracranial hemorrhage (sICH), and 90-day mortality.

RESULTS

Four RCTs with 988 patients (432 in the MM arm and 556 in the MT arm), were included. Patients receiving MT had significantly higher rate of mRS 0-2 (OR = 1.994, 95% CI: 1.319-3.012) and mRS 0-3 (OR = 2.259, 95% CI: 1.166-4.374) at 3 months in comparison to patients receiving MM. Mortality was also significantly reduced in the MT group (OR = 0.640, 95% CI: 0.493-0.831). However, increased odds of sICH were found in the MT group compared to the MM group (OR = 8.193, 95% CI: 2.451-27.389). No difference was observed in terms of NIHSS at 24 hours between the two arms.

CONCLUSIONS

Despite the higher risk of sICH, MT was associated with superior functional outcomes and reduced mortality compared to MM in BAO patients. A revision of current guidelines for treatment of acute ischemic stroke from basilar artery occlusion should be considered.

Histologically interpretable clot radiomic features predict treatment outcomes of mechanical thrombectomy for ischemic stroke

PURPOSE

Radiomics features (RFs) extracted from CT images may provide valuable information on the biological structure of ischemic stroke blood clots and mechanical thrombectomy outcome. Here, we aimed to identify RFs predictive of thrombectomy outcomes and use clot histomics to explore the biology and structure related to these RFs.

METHODS

We extracted 293 RFs from co-registered non-contrast CT and CTA. RFs predictive of revascularization outcomes defined by first-pass effect (FPE, near to complete clot removal in one thrombectomy pass), were selected. We then trained and cross-validated a balanced logistic regression model fivefold, to assess the RFs in outcome prediction. On a subset of cases, we performed digital histopathology on the clots and computed 227 histomic features from their whole slide images as a means to interpret the biology behind significant RF.

RESULTS

We identified 6 significantly-associated RFs. RFs reflective of continuity in lower intensities, scattered higher intensities, and intensities with abrupt changes in texture were associated with successful revascularization outcome. For FPE prediction, the multi-variate model had high performance, with AUC = 0.832 ± 0.031 and accuracy = 0.760 ± 0.059 in training, and AUC = 0.787 ± 0.115 and accuracy = 0.787 ± 0.127 in cross-validation testing. Each of the 6 RFs was related to clot component organization in terms of red blood cell and fibrin/platelet distribution. Clots with more diversity of components, with varying sizes of red blood cells and fibrin/platelet regions in the section, were associated with RFs predictive of FPE.

CONCLUSION

Upon future validation in larger datasets, clot RFs on CT imaging are potential candidate markers for FPE prediction.

Tectonic infarct analysis: A computational tool for automated whole-brain infarct analysis from TTC-stained tissue

Background

Infarct volume measured from 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain slices is critical to in vivo stroke models. In this study, we developed an interactive, tunable, software that automatically computes whole-brain infarct metrics from serial TTC-stained brain sections.

Methods

Three rat ischemic stroke cohorts were used in this study (Total n = 91 rats; Cohort 1 n = 21, Cohort 2 n = 40, Cohort 3 n = 30). For each, brains were serially-sliced, stained with TTC and scanned on both anterior and posterior sides. Ground truth annotation and infarct morphometric analysis (e.g., brain-V_brain, infarct-V_infarct, and non-infarct-V_non-infarct volumes) were completed by domain experts. We used Cohort 1 for brain and infarct segmentation model development (n = 3 training cases with 36 slices [18 anterior and posterior faces], n = 18 testing cases with 218 slices [109 anterior and posterior faces]), as well as infarct morphometrics automation. The infarct quantification pipeline and pre-trained model were packaged as a standalone software and applied to Cohort 2, an internal validation dataset. Finally, software and model trainability were tested as a use-case with Cohort 3, a dataset from a separate institute.

Results

Both high segmentation and statistically significant quantification performance (correlation between manual and software) were observed across all datasets. Segmentation performance: Cohort 1 brain accuracy = 0.95/f1-score = 0.90, infarct accuracy = 0.96/f1-score = 0.89; Cohort 2 brain accuracy = 0.97/f1-score = 0.90, infarct accuracy = 0.97/f1-score = 0.80; Cohort 3 brain accuracy = 0.96/f1-score = 0.92, infarct accuracy = 0.95/f1-score = 0.82. Infarct quantification (cohort average): V_brain (ρ = 0.87, p < 0.001), V_infarct (0.92, p < 0.001), V_non-infarct (0.80, p < 0.001), %infarct (0.87, p = 0.001), and infarct:non-infact ratio (ρ = 0.92, p < 0.001).

Conclusion

Tectonic Infarct Analysis software offers a robust and adaptable approach for rapid TTC-based stroke assessment.

Middle meningeal artery embolization as a perioperative adjunct to surgical evacuation of nonacute subdural hematomas: An multicenter analysis of safety and efficacy

BACKGROUND

By 2030, nonacute subdural hematomas (NASHs) will likely be the most common cranial neurosurgery pathology. Treatment with surgical evacuation may be necessary, but the recurrence rate after surgery is as high as 30%. Minimally invasive middle meningeal artery embolization (MMAE) during the perioperative period has been posited as an adjunctive treatment to decrease the potential for recurrence after surgical evacuation. We evaluated the safety and efficacy of concurrent MMAE in a multi-institutional cohort.

METHODS

Data from 145 patients (median age 73 years) with NASH who underwent surgical evacuation and MMAE in the perioperative period were retrospectively collected from 15 institutions. The primary outcome was the rate of recurrence requiring repeat surgical intervention. We collected clinical, treatment, and radiographic data at initial presentation, after evacuation, and at 90-day follow-up. Outcomes data were also collected.

RESULTS

Preoperatively, the median hematoma width was 18 mm, and subdural membranes were present on imaging in 87.3% of patients. At 90-day follow-up, median NASH width was 6 mm, and 51.4% of patients had at least a 50% decrease of NASH size on imaging. Eight percent of treated NASHs had recurrence that required additional surgical intervention. Of patients with a modified Rankin Scale score at last follow-up, 87.2% had the same or improved mRS score. The total all-cause mortality was 6.0%.

CONCLUSION

This study provides evidence from a multi-institutional cohort that performing MMAE in the perioperative period as an adjunct to surgical evacuation is a safe and effective means to reduce recurrence in patients with NASHs.

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.

A Systematic Review of Non-Galenic Pial Arteriovenous Fistulas

OBJECTIVE

Non-galenic pial arteriovenous fistulas (NGPAVFs) are rare cerebrovascular pathologies accounting for only 1.6%-4.8% of all brain vascular malformations. We performed a comprehensive review of NGPAVF cases reported in the literature to further characterize their clinical patterns of presentation, angiographic features, management, clinical outcomes, and complications.

METHODS

We searched PubMed, Google Scholar, and Embase from each database's earliest records to April 2022 for all relevant English language articles. A total of 3280 articles were screened to identify those that met prespecified inclusion criteria. Differences in clinical outcomes between children (≤18 years old) and adults (>18 years old) and those articles in which NGPAVFs were associated with the presence of a varix or a hemorrhage were statistically examined.

RESULTS

A total of 242 patients in 86 articles were included. The mean patient age was 18.51 ± 18.80 years. The male-to-female ratio was 1.44:1. Headache was the most common initial presentation (42.6%) in the study cohort. Hemorrhage occurred at a significantly higher frequency in adults (P = 0.004), whereas more children presented with congestive heart failure (P < 0.001). Surgical, endovascular, and combination therapy led to comparable rates of complete NGPAVF obliteration (86.8%, 85.2%, and 88.5%, respectively). Fifty-nine patients (24.4%) experienced a complication, ranging from minor neurological deficit to severe hemorrhage. The mortality rate for the overall cohort was 3.3%, and all deceased patients had a varix associated with their fistulas.

CONCLUSIONS

To our knowledge, we report the largest literature review describing the clinical course and characteristics of NGPAVFs. All treatment approaches resulted in favorable obliteration rates and overall patient outcomes.

RNA Expression Signatures of Intracranial Aneurysm Growth Trajectory Identified in Circulating Whole Blood

After detection, identifying which intracranial aneurysms (IAs) will rupture is imperative. We hypothesized that RNA expression in circulating blood reflects IA growth rate as a surrogate of instability and rupture risk. To this end, we performed RNA sequencing on 66 blood samples from IA patients, for which we also calculated the predicted aneurysm trajectory (PAT), a metric quantifying an IA's future growth rate. We dichotomized dataset using the median PAT score into IAs that were either more stable and more likely to grow quickly. The dataset was then randomly divided into training (n = 46) and testing cohorts (n = 20). In training, differentially expressed protein-coding genes were identified as those with expression (TPM > 0.5) in at least 50% of the samples, a q-value < 0.05 (based on modified F-statistics with Benjamini-Hochberg correction), and an absolute fold-change ≥ 1.5. Ingenuity Pathway Analysis was used to construct networks of gene associations and to perform ontology term enrichment analysis. The MATLAB Classification Learner was then employed to assess modeling capability of the differentially expressed genes, using a 5-fold cross validation in training. Finally, the model was applied to the withheld, independent testing cohort (n = 20) to assess its predictive ability. In all, we examined transcriptomes of 66 IA patients, of which 33 IAs were "growing" (PAT ≥ 4.6) and 33 were more "stable". After dividing dataset into training and testing, we identified 39 genes in training as differentially expressed (11 with decreased expression in "growing" and 28 with increased expression). Model genes largely reflected organismal injury and abnormalities and cell to cell signaling and interaction. Preliminary modeling using a subspace discriminant ensemble model achieved a training AUC of 0.85 and a testing AUC of 0.86. In conclusion, transcriptomic expression in circulating blood indeed can distinguish "growing" and "stable" IA cases. The predictive model constructed from these differentially expressed genes could be used to assess IA stability and rupture potential.

Carotid Artery Stenting Using the Walrus Balloon Guide Catheter With Flow Reversal for Proximal Embolic Protection: Technical Description and Single-Center Case Series

BACKGROUND

The use of modern transfemoral balloon guide catheters (BGC) for flow reversal during carotid artery stenting is scarcely described in the literature but represents a promising and efficient technique for embolic protection.

OBJECTIVE

To describe a flow-reversal technique using the Walrus BGC (Q'Apel Medical Inc.) and report our center's experience.

METHODS

We performed a retrospective analysis of data for consecutive patients aged 18 years or older who underwent elective carotid artery stenting with the use of flow reversal through the Walrus BGC between July 2020 and September 2021. Patient characteristics, procedural details, and clinical follow-up were evaluated.

RESULTS

One hundred and five patients were included. Mean age was 69.8 ± 9.4 years, and 36 (34.3%) were women. The most common comorbidities were hyperlipidemia (76.2%) and hypertension (57.1%). Fifty-nine (56.2%) patients were symptomatic. Ninety-nine (94.3%) patients had stenosis ≥70%. Contralateral stenosis ≥50% was present in 44 patients (41.9%). Distal filters were used after flow reversal was established in 90 patients (85.7%). Angioplasty was performed in 85 patients (80.9%). Stenting was successful in 100% of cases. No periprocedural transient ischemic attacks (TIAs) or strokes occurred. Stroke occurred in 2 patients (1.9%) during the 30-day follow-up period, resulting in 1 (0.9%) death.

CONCLUSION

In our experience, this technique was safe, feasible, and efficient, with 100% technical success and no periprocedural thromboembolic complications. More extensive studies are needed to establish the role of proximal protection with flow reversal using modern BGCs.

Not a trifecta: complementary use of carotid artery revascularization techniques in the era of hybrid neurosurgery

OBJECTIVE

Carotid stenosis is currently treated by carotid endarterectomy (CEA), carotid artery stenting (CAS), or transcarotid artery revascularization (TCAR). This study sought to add to the literature by providing real-world data comparing the safety and effectiveness associated with the performance of these carotid revascularization techniques by dual-trained neurosurgeons.

METHODS

The authors performed a retrospective review of carotid stenosis databases at two US centers. Patients treated by CEA, transfemoral CAS, or TCAR for atherosclerotic carotid artery disease were included. Clinical outcomes were compared at 30 days after the procedure.

RESULTS

Seven hundred eighty patients were included (583 with CAS, 165 with CEA, and 32 with TCAR). Overall, 486 patients (62.3%) were men, and 393 (50.4%) had left-sided carotid stenosis. Most patients (n = 617, 79.1%) had symptomatic disease. Among the three treatment groups, there were no statistically significant differences with respect to 30-day ischemic events (CAS 3.8%, CEA 1.8%, TCAR 6.3%; p = 0.267) or 30-day mortality rates (CAS 3.6%, CEA 2.4%, TCAR 3.1%; p = 0.857). Male sex had significantly lower odds of 30-day transient ischemic attack (TIA) or stroke in both univariable (p = 0.024) and multivariable (p = 0.023) regression models. Increasing age had significantly higher odds of 30-day mortality on univariable (p = 0.006) and multivariable (p = 0.003) regression. Patients with the occurrence of 30-day TIA or stroke also had significantly higher odds of 30-day mortality on univariable (p < 0.001) and multivariable (p < 0.001) regression.

CONCLUSIONS

This real-world experience reflects the current practice of hybrid neurosurgery at two high-volume tertiary care centers and suggests that all three treatment modalities have comparable safety and effectiveness if patients are properly selected.

Use of drug-eluting, balloon-expandable resolute onyx coronary stent as a novel treatment strategy for vertebral artery ostial stenosis: Case series

INTRODUCTION

Vertebral artery (VA) ostial stenosis is notoriously difficult to treat using bare-metal stents owing to high rates of restenosis and stent kinking and breakage. We investigated the safety and effectiveness of treatment with a drug-eluting, balloon-expandable coronary stent (Resolute Onyx, Medtronic).

METHODS

Our prospectively maintained database was retrospectively searched for consecutive patients diagnosed with VA ostial stenosis who underwent Resolute Onyx stenting with/without angioplasty between January 1, 2015 and January 1, 2022. Patient demographics and clinical and radiographic presentations were recorded. Occlusion location, stenosis severity, contralateral disease, devices used, and intraprocedural and postprocedural complications were noted. Outcomes were assessed based on new or recurrent stroke, transient ischemic attack (TIA), or intracranial hemorrhage (ICH). Patients were followed up clinically and with radiographic imaging for in-stent stenosis.

RESULTS

Twenty-six patients were included in our study (21 men [80.8%]; mean age 70.3 ± 9.8 years). Symptomatic patients presented with TIA (11/26, 42.3%) and stroke (10/26; 38.5%). Mean stenosis in the study cohort was 74.9 ± 13.0%. One (3.8%) intraprocedural complication was encountered whereby the stent failed to open despite several attempts and was exchanged with a new one without issues. No in-hospital postprocedure stroke, TIA, or mortality was reported. During a mean 16.2 ± 13.6 months' follow up, two patients developed symptomatic in-stent restenosis that was treated with balloon angioplasty.

CONCLUSIONS

We report the first case series of Resolute Onyx drug-eluting stenting including 30-day postprocedure stroke/TIA rates and clinical/radiographic follow up and demonstrate safe and effective treatment of symptomatic and asymptomatic VA ostial stenosis.

Transfemoral Flow-Reversal for Carotid Artery Stenting with Balloon Guide Catheter: Proof of Concept with Robotic Transcranial Doppler

In this video, we demonstrate our technique for transfemoral carotid artery stenting (CAS) with flow-reversal through a Walrus balloon guide catheter (BGC) using robotic transcranial Doppler (rTCD) monitoring. Before crossing the plaque for distal filter placement and/or angioplasty, the BGC is inflated and the three-way stopcock opened, allowing back-bleeding. Immediately, the rTCD shows a change in blood-flow direction, indicating flow-reversal, which likely occurs due to a passive pressure gradient between the intracranial compartment and the atmospheric pressure. Then, the filter is placed with reduced risk of displacing plaque fragments, and angioplasty and stenting are performed with dual protection afforded by the BGC and filter. This technique may confer greater safety for CAS. Although in this case rTCD was used for proof of concept, it could also be used as a tool to monitor embolic load during CAS procedures.

First reported single-surgeon transpalpebral hybrid approach for indirect cavernous carotid fistula: illustrative case

BACKGROUND

Failure to reach the cavernous sinus after multiple transvenous attempts, although rare, can be challenging for neurointerventionists. The authors sought to demonstrate technical considerations and nuances of the independent performance of a novel hybrid surgical and endovascular transpalpebral approach through the superior ophthalmic vein (SOV) for direct coil embolization of an indirect carotid cavernous fistula (CCF), and they review salient literature regarding the transpalpebral approach.

OBSERVATIONS

An illustrative case, including patient history and presentation, was reviewed. PubMed, MEDLINE, and Embase databases were searched for articles published between January 1, 2000, and September 30, 2021, that reported ≥1 patient with a CCF treated endovascularly via the SOV approach. Data extracted included sample size, treatment modality, surgical technique, performing surgeon specialty, and procedure outcome. The authors’ case illustration demonstrates the technique for the hybrid transpalpebral approach. For the review, 273 unique articles were identified; 14 containing 74 treated patients fulfilled the inclusion criteria. Oculoplastic surgery was the most commonly involved specialty (5 of 14 studies), followed by ophthalmology (3 of 14). Coiling alone was the treatment of choice in 12 studies, with adjunctive use of Onyx (Medtronic) in 2.

LESSONS

The authors’ technical case description, video, illustrations, and review provide endovascular neurosurgeons with a systematic guide to conduct the procedure independently.

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.

A systematic review and meta-analysis of the Derivo Embolization Device: a novel surface-modified flow diverter for intracranial aneurysm treatment

BACKGROUND

Surface-modified flow diverters (FDs) designed to reduce thrombogenicity represent the next frontier for intracranial aneurysm treatment. The Derivo Embolization Device (DED) is a novel FD with titanium oxide and titanium oxynitride finishing of the struts. We performed a systematic review of pertinent literature, aiming to evaluate the device's effectiveness and safety.

METHODS

A literature search of PubMed, Embase, and MEDLINE was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Five studies comprising 481 aneurysms were included. These studies were conducted in Turkey, Brazil, Germany, Poland, and Italy; two were prospective and three were retrospective. Twenty-six aneurysms (5.4%) were ruptured. The antiplatelet regimens were heterogeneous, but dual antiplatelet therapy was administered preprocedurally in all studies and maintained for 3-12 months before a switch to single antiplatelet therapy. The rate of periprocedural ischemic and hemorrhagic complications was 4.9% (95% CI 2.9% to 7%). Adjunctive coiling was used in 25.6% (95% CI 11.4% to 39.8%) of aneurysms. The complete angiographic occlusion rate was 81.4% (95% CI 71.3% to 91.5%), mortality rate was 2.1% (95% CI 0.4% to 3.9%), with follow-up ranging from 9 to 18 months. Delayed aneurysm rupture was reported in one patient.

CONCLUSIONS

The DED has been increasingly used in other countries. We identified low rates of periprocedural complications and mortality and a high rate of complete occlusion.

Initial investigation of predicting hematoma expansion for intracerebral hemorrhage using imaging biomarkers and machine learning

PURPOSE

Intracerebral Hemorrhage (ICH) is one of the most devastating types of strokes with mortality and morbidity rates ranging from about 51%-65% one year after diagnosis. Early hematoma expansion (HE) is a known cause of worsening neurological status of ICH patients. The goal of this study was to investigate whether non-contrast computed tomography imaging biomarkers (NCCT-IB) acquired at initial presentation can predict ICH growth in the acute stage.

MATERIALS AND METHODS

We retrospectively collected NCCT data from 200 patients with acute (<6 hours) ICH. Four NCCT-IBs (blending region, dark hole, island, and edema) were identified for each hematoma, respectively. HE status was recorded based on the clinical observation reported in the patient chart. Supervised machine learning models were developed, trained, and tested for 15 different input combinations of the NCCT-IBs to predict HE. Model performance was assessed using area under the receiver operating characteristic curve and probability for accurate diagnosis (PAD) was calculated. A 20-fold Monte-Carlo cross validation was implemented to ensure model reliability on a limited sample size of data, by running a myriad of random training/testing splits.

RESULTS

The developed algorithm was able to predict expansion utilizing all four inputs with an accuracy of 70.17%. Further testing of all biomarker combinations yielded P _AD ranging from 0.57, to 0.70.

CONCLUSION

Specific attributes of ICHs may influence the likelihood of HE and can be evaluated via a machine learning algorithm. However, certain parameters may differ in importance to reach accurate conclusions about potential expansion.

Abstract TP76: The Impact Of Registries In Stroke Literature

Introduction: Registries represent a main source of data to the advances in medical literature. In stroke medicine, they serve as key points of discussion and elaboration for future clinical trials, as well as evaluation tools for several treatment modalities in different patient populations. We performed an analysis of recent stroke registries to evaluate their impact in literature.

Methods: We performed PubMed and Google Scholar search using keywords with Boolean operators to identify studies deriving from stroke registries between January 2000 and June 2021. All registries identified were further characterized regarding study design, sample size, number of centers, number of peer reviewed articles or conference abstracts originating from it, with their respective number of citations and impact factor of journals.

Results: A total of 51 registries were identified, comprising 43584 patients. Forty-three (84.3%) were prospective. Forty-five (88.2%) were multicenter. Sixteen (31.4%) focused in a specific device for mechanical thrombectomy. Twenty-seven (52.9%) were registered on clinicaltrials.gov. The most participating countries were United States in 16 (31.4%) and Germany in 8 (15.7%). Twenty-seven (52.9%) registries originated a total of 295 peer-reviewed articles, 6841 citations and a sum of impact factors of 1282.8. The median impact factor of journals publishing articles from registries was 5.51 (interquartile range, 3.27-7.91). The median number of citations per article was 13 (interquartile range, 4-37). Between registered and unregistered registries, there was no significant difference in the median number of publications (P=0.08), citations (P=0.158) or impact factor (P=0.124). Between registries specific and unspecific to a certain device, there was no significant difference in median number of publications (P=1.67), citations (P=0.631) or impact factor (P=0.509).

Conclusions: Stroke registries provide a meaningful data source for literature regardless of registration or specificity to a certain device, and represent a key mechanism in the advances of stroke care. Contribution to stroke registries are key mechanism to elucidate clinical questions that require large sample size and should be incentivized.

Initial investigation of the use of angiographic parametric imaging for early prognosis of delayed cerebral ischemia in patients with subarachnoid hemorrhage

PURPOSE

Subarachnoid Hemorrhage (SAH) is a lethal hemorrhagic stroke that account for 25% of cerebrovascular deaths. As a result of the initial bleed, a chain of physiological events are initiated which may lead to Delayed Cerebral Ischemia (DCI). As of now we have no diagnostic capability to identify patients which may present DCI a few weeks after initial presentation. We propose to investigate whether a data driven approach using angiographic parametric imaging (API) may predict occurrence of the DCI.

MATERIALS AND METHODS

Digital Subtraction Angiographic (DSA) sequences from 125 SAH patients were used retrospectively to perform API assessment of the entire brain hemisphere where the hemorrhage was detected. Four Regions of Interests (ROIs) were placed to extract five average API biomarkers in the lateral and AP DSAs. Data driven analysis using Logistic Regression was performed for various API parameters and ROIs to find the optimal configuration to maximize the prognosis accuracy. Each model performance was evaluated using area under the curve of the receiver operator characteristic (AUROC).

RESULTS

Data driven approach with API has a 60% accuracy predicting DCI occurrence. We determined that location of the ROI for extraction of the API parameters is very important for the data driven model performance. Normalizing the values using the inlet velocities for each patient yield higher and more consistent results. Single API biomarkers models had poor prediction accuracies, barely better than chance.

CONCLUSIONS

This effectiveness exploratory study demonstrates for the first time, that prognosis of the DCI in SAH patients, is feasible and warrants a more in-depth investigation.

First U.S. Experience Using the Pipeline Flex Embolization Device with Shield Technology for Treatment of Intracranial Aneurysms

BACKGROUND

The Pipeline Flex Embolization Device with Shield technology (PED-Shield [Medtronic, Dublin, Ireland]) is a third-generation flow diverter. Surface modification of the mesh with phosphorylcholine covalently bound to the metal struts aims to reduce thrombogenicity. In the present study, we report the results from the first U.S. series of patients with intracranial aneurysms treated with the PED-Shield and a comprehensive systematic literature review.

METHODS

We retrospectively collected the patient demographics, aneurysm characteristics, procedural details, and periprocedural complications from our prospectively maintained endovascular database (April 2021 to July 2021). Our literature review encompassed 3 databases (PubMed, Embase, and MEDLINE).

RESULTS

Ten patients with 11 anterior circulation unruptured wide-necked aneurysms (10 saccular, 1 fusiform) were included. The average patient age was 64.7 years (range, 45-86 years), and 9 were women. One device demonstrated insufficient distal opening. No other technical issues or intraprocedural complications had occurred. After the procedure, 1 patient had developed a groin hematoma and 1 had experienced a small intracranial hemorrhage, with no clinical repercussions. All patients were discharged with dual-antiplatelet therapy. In the review, we identified 15 studies. Most had been conducted in Europe and South America and 3 were U.S. case reports of compassionate use of the device.

CONCLUSIONS

In our initial periprocedural experience with the PED-Shield for intracranial aneurysm treatment, the device demonstrated an excellent performance and no major complications. Further studies are required to evaluate the long-term follow-up results and the safety of different antiplatelet regimens.

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.

Carotid artery revascularization using the Walrus balloon guide catheter: safety and feasibility from a US multicenter experience

INTRODUCTION

The Walrus balloon guide catheter (BGC) is a new generation of BGC, designed to eliminate conventional limitations during mechanical thrombectomy.

OBJECTIVE

To report a multi-institutional experience using this BGC for proximal flow control (PFC) in the setting of carotid artery angioplasty/stenting (CAS) in elective (eCAS) and tandem strokes (tCAS).

METHODS

Prospectively maintained databases at 8 North American centers were queried to identify patients with cervical carotid disease undergoing eCAS/tCAS with a Walrus BGC.

RESULTS

110 patients (median age 68, 64.6% male), 80 (72.7%) undergoing eCAS and 30 (27.3%) tCAS procedures, were included (median cervical carotid stenosis 90%; 46 (41.8%) with contralateral stenosis). Using a proximal flow-arrest technique in 95 (87.2%) and flow-reversal in 14 (12.8%) procedures, the Walrus was navigated into the common carotid artery successfully in all cases despite challenging arch anatomy (31, 28.2%), with preferred femoral access (103, 93.6%) and in monitored anesthesia care (90, 81.8%). Angioplasty and distal embolic protection devices (EPDs) were used in 91 (83.7%) and 58 (52.7%) procedures, respectively. tCAS led to a modified Thrombolysis in Cerebral Infarction 2b/3 in all cases. Periprocedural ischemic stroke (up to 30 days postoperatively) rate was 0.9% (n=1) and remote complications occurred in 2 (1.8%) cases. Last follow-up modified Rankin Scale score of 0-2 was seen in 95.3% of eCAS cohort, with no differences in complications in the eCAS subgroup between PFC only versus PFC and distal EPD (median follow-up 4.1 months).

CONCLUSION

Walrus BGC for proximal flow control is safe and effective during eCAS and tCAS. Procedural success was achieved in all cases, with favorable safety and functional outcomes on short-term follow-up.

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.

An Image-Based Workflow for Objective Vessel Wall Enhancement Quantification in Intracranial Aneurysms

BACKGROUND

VWE in contrast-enhanced magnetic resonance imaging (MRI) is a potential biomarker for the evaluation of IA. The common practice to identify IAs with VWE is mainly based on a visual inspection of MR images, which is subject to errors and inconsistencies. Here, we develop and validate a tool for the visualization, quantification and objective identification of regions with VWE.

METHODS

N = 41 3D T1-MRI and 3D TOF-MRA IA images from 38 patients were obtained and co-registered. A contrast-enhanced MRI was normalized by the enhancement intensity of the pituitary stalk and signal intensities were mapped onto the surface of IA models generated from segmented MRA. N = 30 IAs were used to identify the optimal signal intensity value to distinguish the enhancing and non-enhancing regions (marked by an experienced neuroradiologist). The remaining IAs (n = 11) were used to validate the threshold. We tested if the enhancement area ratio (EAR-ratio of the enhancing area to the IA surface-area) could identify high risk aneurysms as identified by the ISUIA clinical score.

RESULTS

A normalized intensity of 0.276 was the optimal threshold to delineate enhancing regions, with a validation accuracy of 81.7%. In comparing the overlap between the identified enhancement regions against those marked by the neuroradiologist, our method had a dice coefficient of 71.1%. An EAR of 23% was able to discriminate high-risk cases with an AUC of 0.7.

CONCLUSIONS

We developed and validated a pipeline for the visualization and objective identification of VWE regions that could potentially help evaluation of IAs become more reliable and consistent.