Updated estimates of large and medium vessel strokes, mechanical thrombectomy trends, and future projections indicate a relative flattening of the growth curve but highlight opportunities for expanding endovascular stroke care

A deep learning method to identify and localize large-vessel occlusions from cerebral digital subtraction angiography

BACKGROUND AND PURPOSE

An essential step during endovascular thrombectomy is identifying the occluded arterial vessel on a cerebral digital subtraction angiogram (DSA). We developed an algorithm that can detect and localize the position of occlusions in cerebral DSA.

METHODS

We retrospectively collected cerebral DSAs from a single institution between 2018 and 2020 from 188 patients, 86 of whom suffered occlusions of the M1 and proximal M2 segments. We trained an ensemble of deep-learning models on fewer than 60 large-vessel occlusion (LVO)-positive patients. We evaluated the model on an independent test set and evaluated the truth of its predicted localizations using Intersection over Union and expert review.

RESULTS

On an independent test set of 166 cerebral DSA frames with an LVO prevalence of 0.19, the model achieved a specificity of 0.95 (95% confidence interval [CI]: 0.90, 0.99), a precision of 0.7450 (95% CI: 0.64, 0.88), and a sensitivity of 0.76 (95% CI: 0.66, 0.91). The model correctly localized the LVO in at least one frame in 13 of the 14 LVO-positive patients in the test set. The model achieved a precision of 0.67 (95% CI: 0.52, 0.79), recall of 0.69 (95% CI: 0.46, 0.81), and a mean average precision of 0.75 (95% CI: 0.56, 0.91).

CONCLUSION

This work demonstrates that a deep learning strategy using a limited dataset can generate effective representations used to identify LVOs. Generating an expanded and more complete dataset of LVOs with obstructed LVOs is likely the best way to improve the model's ability to localize LVOs.

Population-based estimates suggest middle meningeal artery embolization for subdural hematomas could significantly expand the scope of neurovascular therapies

BACKGROUND

This study quantifies the impact of middle meningeal artery embolization (MMAE) for subdural hematomas (SDHs) by estimating a target population.

METHODS

A population-based study at a tertiary hospital, the main SDH facility for a four-county population, used primary ICD-10 codes over 3 years to collate SDH hospitalizations. Clinical and imaging data confirmed traumatic versus non-traumatic and acute versus non-acute (mixed or chronic) SDH. The MMAE-eligible population included patients with non-traumatic, non-acute SDH aged ≥18 years plus patients with 'traumatic' but non-acute SDH aged ≥60 years presenting with a fall. This was contrasted with the rate of large vessel strokes in the same population.

RESULTS

1279 hospitalizations with a primary ICD-10 SDH diagnosis were identified, with 389 from the study population. Excluding repeat admissions, 350 patients were analyzed, 233 (67%) traumatic, and 117 (33%) non-traumatic SDH. Regarding etiology, 'fall ≥60 years' was the most common category in the entire cohort (n=156; 45% (95% CI 39% to 50%)). The SDH rate was 52/100 000 persons/year (95% CI 47 to 57). The rate of all non-traumatic, non-acute SDH in patients aged ≥18 years was 17/100 000 persons/year (95% CI 15 to 20), combining with 'traumatic' but non-acute fall-related SDH in patients aged ≥60 years yielded 41/100 000 persons/year (95% CI 36 to 47). This demographic may represent an MMAE-eligible population, exceeding large vessel stroke rates (31/100 000 persons/year) in the same population, estimating 139 387 potential MMAE cases/year (95% CI 121 517 to 158 168) in the USA.

CONCLUSION

MMAE could transform non-acute SDH management, especially in the elderly, potentially surpassing the impact of large vessel stroke. Clinical trials are essential for validation of its efficacy and safety compared with standard management.

Expansion of Telestroke Coverage in Community Hospitals: Unifying Stroke Care and Reducing Transfer Rate

OBJECTIVE

Telestroke (TS) service has been shown to improve stroke diagnosis timing and accuracy, facilitate treatment decisions, and decrease interfacility transfers. Expanding TS service to inpatient units at the community hospital provides an opportunity to follow up on stroke patients and optimize medical management. This study examines the outcome of expanding TS coverage from acute emergency room triage to incorporate inpatient consultation.

METHODS

We studied the effect of expanding TS to inpatient consultation service at 19 regional hospitals affiliated with Promedica Stroke Network. We analyzed data pre- and post-TS expansion. We reviewed changes in TS utilization, admission rate, thrombolytic therapy, patient transfer rate, and diagnosis accuracy.

RESULTS

Between January 2018 and June 2022, a total of 9,756 patients were evaluated in our stroke network (4,705 in pre- and 5,051 in the post-TS expansion). In the post-TS expansion period, stroke patients' admission at the spoke hospital increased from 18/month to 40/month, and for TIA from 11/month to 16/month. TS cart use increased from 12% to 35.2%. Patient transfers to hub hospital decreased by 31%. TS service expansion did not affect intravenous thrombolytic therapy rate or door-to-needle time. There was no difference in length of stay or readmission rate, and the patients at the spoke hospitals had a higher rate of home discharge 57.38% compared with 52.58% at hub hospital.

INTERPRETATION

Telestroke service expansion to inpatient units helped decrease transfers and retain patients in their communities, increased stroke and TIA diagnosis accuracy, and did not compromise patients' hospitalization or outcome. ANN NEUROL 2024;95:576-582.

Cost-Effectiveness of a Direct-Aspiration First-Pass Technique versus Stent Retriever in Mechanical Thrombectomy

OBJECTIVE

A direct-aspiration first-pass technique (ADAPT) in mechanical thrombectomy has been described in recent studies as an efficacious strategy compared with using a stent retriever (SR). We sought to evaluate for cost differences of ADAPT technique versus SR as an initial approach.

METHODS

We conducted a retrospective analysis of consecutive patients with mechanical thrombectomy at our institution between 2022 and 2023. Patients were grouped into ADAPT with/without SR as a rescue strategy and SR as an initial approach with allowance of concomitant aspiration. Direct cost data (consumables) were obtained. Baseline demographics, stroke metrics, procedure outcomes and cost, and last follow-up outcomes in modified Rankin Scale were compared between 2 groups.

RESULTS

Fifty-six patients were included. Thirty-seven (66.1%) underwent ADAPT, with 11 (29.7%) eventually requiring an SR. Mean age was 64.8 years. The average National Institutes of Health Stroke Scale score was 13.2 in the ADAPT group and 14.0 in the SR group (P = 0.68), with a similar proportion of tissue plasminogen activator (P = 0.53), site of occlusion (P = 0.66), and tandem occlusion (P = 0.69) between the groups. Recanalization was achieved in 94.6% of all patients, with an average of 1.9 passes, 89.3% being TICI 2B or above, with no differences between the 2 groups. Significantly lower cost (P < 0.01) was observed in ADAPT ($14,243.4) compared with SR ($19,003.6). Average follow-up duration was 180.2 days, with mortality of 23.2%. At last follow-up, 55.4% remained functionally independent (modified Rankin Scale score <3) with no difference (P = 0.56) between the ADAPT (59.5%) and SR (47.4%) groups.

CONCLUSIONS

Outcomes were comparable between the ADAPT and SR groups. ADAPT reduced procedural consumables cost by approximately $5000 (25%), even if stent retrievers were allowed to be used for rescue. Establishing ADPAT as initial approach may bring significant direct cost savings while obtaining similar outcomes.

Management of intracranial arterial stenosis during mechanical thrombectomy: Survey of neuro-interventionalists

BACKGROUND

The optimal management of emergent large vessel occlusion due to underlying intracranial stenosis (intracranial stenosis related large vessel occlusion) remains unknown. The primary aim of this survey analysis was to measure variation in the clinical management of intracranial stenosis related large vessel occlusion during mechanical thrombectomy.

METHODS

A survey was designed using a web-based survey-building platform and distributed via the Society of NeuroInterventional Surgery (SNIS) and the Society of Vascular and Interventional Neurology (SVIN) websites for a response. Predictors of respondents' level of comfortability stenting were estimated using a binomial logistic regression model.

RESULTS

We received 105 responses to the survey. Most respondents (54.3%) practiced at an academic Stroke Center. Nearly half of the respondents (49%) had been practicing for 5 or more years independently after fellowship. An average of 54 mechanical thrombectomies were performed by each respondent annually. There was variation in the definition of intracranial stenosis related large vessel occlusion, number of passes performed before pursuing rescue stenting, as well as intra and post-procedural antiplatelet management. Of respondents, 58% felt rescue stenting was very risky, and 55.7% agreed that there was equipoise regarding emergent angioplasty and/or stenting versus medical therapy for intracranial stenosis related large vessel occlusion. Respondents who encountered intracranial stenosis related large vessel occlusion more frequently thought that rescue stenting was less risky.

CONCLUSION

There is notable variability in the diagnosis and management of intracranial stenosis related large vessel occlusion during mechanical thrombectomy. While most respondents felt rescue stenting was risky, the majority believed the benefit could outweigh the risk. The majority of respondents agreed that equipoise exists regarding the management of intracranial stenosis related large vessel occlusion, highlighting the need for clinical trials in this rare patient population.

The incidence of medium vessel occlusions: a population-based study

Introduction

The incidence of medium vessel occlusion (MeVO) is not well known. The objective of our study is to perform a population-based assessment to estimate the incidence of MeVOs.

Methods

Consecutive patients from Olmsted County, Minnesota who presented for acute ischemic stroke seen at Mayo Clinic Hospital from 1/1/2018 to 12/31/2020 who were found to have a MeVO were included in this study. MeVO was defined as occlusion at or beyond the level of the middle cerebral artery M2 segment, anterior cerebral artery A2 segment, posterior cerebral artery P1 segment, and cerebellar arteries. Census data for Olmsted County was obtained from the United States Census Bureau from the year 2020.

Results

A total of 1,718 patients were screened for the study, 77 patients fulfilled inclusion criteria to be included in the study. Presenting NIHSS was 9 (± 7). The population of Olmsted County was estimated to be 162,847. The incidence rate for MeVO was 16 cases (95% CI 12-19) per 100,000 people per year. Based on estimates of the US population in 2020 of 331,449,281 people, we estimate there are 52,236 (95% CI 40,635-64,002) new cases of MeVOs per year.

Conclusion

As the only stroke center in Olmsted County, we have been able to estimate the incidence of ischemic stroke due to MeVO. While the incidence of MeVOs is less than both large and small vessel occlusions, they still represent a significant proportion of strokes with significant morbidity and mortality that would benefit from further studies in both acute intervention and prevention.