Endovascular Contact Aspiration versus Stent Retriever for Revascularization in Patients with Acute Ischemic Stroke and Large Vessel Occlusion: A Cost-Minimization Analysis

Stent retriever versus aspiration based thrombectomy: impact on first pass reperfusion, procedure time, and clinical outcomes in large vessel occlusion. Nationwide registry based cohort study

BACKGROUND

First pass reperfusion (FPR), defined as near complete reperfusion (extended Treatment in Cerebral Ischemia (eTICI) score 2c/3) in a single attempt without rescue therapy has been proposed as a quality metric. However, it remains unclear if the thrombectomy method influences clinical outcome and FPR rate. This study evaluates whether stent retriever and aspiration based thrombectomy differ in FPR rate, technical and clinical outcomes in FPR, and multiple pass reperfusion (MPR).

METHODS

This retrospective, nationwide, multicenter registry study included consecutive patients with proximal anterior or posterior circulation stroke, treated between 2018 and 2021 in Sweden. Outcome measures were FPR rate, procedure time, early neurological improvement (≥4 points on National Institutes of Health Stroke Scale (NIHSS) or a score of 0-1 at 24 hours), favorable functional outcome (modified Rankin Scale score of 0-2 or no decline at 90 days), and mortality at 90 days.

RESULTS

Of 3309 patients (median age 75, median NIHSS 16), 1990 underwent stent retriever and 1319 aspiration based thrombectomy as the firstline method. No difference in FPR rate was observed. Aspiration based thrombectomy showed a shorter procedure time in the FPR group (crude OR (cOR) 6.4 min (95% CI 3.4 to 9.3), adjusted OR (aOR) 8.7 min (95% CI 1.8 to 15.6)) and MPR group (cOR 9.7 min (95% CI 4.0 to 15.4), aOR 17.4 min (95% CI 9.6 to 25.2)), and association with early neurological improvement (cOR 1.21 (95% CI 1.03 to 1.42), aOR 1.40 (95% CI 1.18 to 1.67)) and favorable functional outcome (aOR 1.22 (95% CI 1.01 to 1.47)).

CONCLUSIONS

Our findings suggest that aspiration based thrombectomy was associated with a shorter procedure time and better clinical outcomes than treatment with a stent retriever. No difference was found in FPR rate.

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.

Mechanical Thrombectomy in Stroke-Retrospective Comparison of Methods: Aspiration vs. Stent Retrievers vs. Combined Method-Is Aspiration the Best Starting Point?

Background: There are three main methods of mechanical thrombectomy (MT): using a stent retriever (SR) only (SO), aspiration catheter (AC) only (AO) and the combined method (CM) using both the SR and AC. This paper describes a real-life, single-center experience using SO, AO and CM during 276 consecutive MTs. Methods: The primary endpoint was the frequency of first-pass complete (FPE TICI3). The secondary endpoints were final mTICI 2b-3, procedure duration, clinical outcome and the total number of device passes. The third aim of this study was to test the association between the clinical outcomes in patients treated with each method and various factors. Results: There was a significant difference (p = 0.016) between the groups' FPE TICI3 rates with 46% mTICI 3 in the AO group, 41% in the CM group and 21% in the SO group. AO resulted in procedure time shortening to a mean duration of 43 min, and the scores were 56 min for CM and 63 min for SO (p < 0.0001). There were no significant differences in clinical outcomes or in-hospital mortality. The analysis showed a correlation between good clinical outcomes and the administration of IVT: OR 1.71 (1.03-2.84) p = 0.039. Patients ≥66 years old had higher odds of a bad outcome compared to younger patients in general (OR, 1.99 95% CI, 1.17-3.38; p = 0.011). FPE TICI3 was associated with good functional outcomes in the whole treated cohort (OR, 1.98; 95% CI, 1.21-3.25; p = 0.006). Conclusions: In our series, AO proved to be the best starting point in most cases. It demonstrates good technical efficacy regarding FPE, it is fast and clinical outcomes seem to be the least age- and FPE TICI3-dependent. It can be easily converted into the combined method, which had the second-best outcomes in our cohort.

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.

Time-driven activity-based costing (TDABC) of direct-to-angiography pathway for acute ischemic stroke patients with suspected large vessel occlusion

INTRODUCTION

Direct-to-angiography (DTA) is a novel care pathway for endovascular treatment (EVT) of acute ischemic stroke (AIS) that has been shown to reduce time-to-treatment and improve clinical outcomes for EVT-eligible patients. The institutional costs of adopting the DTA pathway and the many factors affecting costs have not been studied. In this study, we assess the costs and main cost drivers associated with the DTA pathway compared to the conventional CT pathway for patients presenting with AIS and suspected LVO in the anterior circulation.

METHODS

Time driven activity based costing (TDABC) model was used to compare costs of DTA and conventional pathways from the healthcare institution perspective. Process mapping was used to outline all activities and resources (personnel, equipment, materials) needed for each step in both pathways. The cost model was developed using our institutional patient database and average New York state wages for personnel costs. Total, incremental and proportional costs were calculated based on institutional and patient factors affecting the pathways.

RESULTS

DTA pathway accrued additional $82,583.61 (9%) in total costs compared to the conventional approach for all AIS patients. For EVT-ineligible patients, the DTA pathway incurred additional $82,964.37 (76%) in total costs compared to the CT pathway. For EVT eligible patients, the total and per-patient costs were greater in the CT pathway by $380.76 (0.04%) and $5.60 (0.04%) respectively.

CONCLUSION

As the DTA pathway incurred additional $82,964.37 for EVT-ineligible patients, appropriate patient selection criteria are needed to avoid transferring EVT-ineligible patients to the angiography suite.

Standardized approach to direct first pass aspiration technique for endovascular thrombectomy: Description and initial experience with CANADAPT

BACKGROUND

Endovascular thrombectomy (EVT) is standard of care for acute ischemic stroke. Stent assisted EVT with aspiration (SOLUMBRA) technique has remained a mainstay approach. There is growing evidence that A Direct Aspiration First Pass Technique (ADAPT) is a safe, efficient and effective approach for EVT, offering several advantages. This study describes and reports initial institutional experience in the use of a standardized scientific based aspiration only technique: CANADAPT.

METHODS

Single center prospective cohort study was performed on consecutive patients treated for large/medium vessel ischemic stroke with CANADAPT. Intravenous thrombolytics were administered according to routine practice, independent of the decision to proceed with EVT. A sequential stepwise aspiration only technique was then applied, CANADAPT, consisting of three maneuvers, A, B and C. The reperfusion success rate, number of passes, use of rescue technique, complication rate and procedural cost were determined.

RESULTS

Twenty-two patients were included in this case series representing M1 (17, 77%), M1/2 (2, 9%), carotid-T (2, 9%) and basilar (1, 5%) occlusions. First pass recanalization was achieved in 11 (50%) of patients. A further four patients had successful reperfusion with a second pass of CANADAPT (total 68% success rate). Only one patient had successful reperfusion with the aspiration catheter at the clot interface (CANADAPT A). All others required some withdrawal of the aspiration catheter for reperfusion (CANADAPT B and C). Seven patients had SOLUMBRA rescue. Of these, five patients (22% of total patients) had further successful reperfusion. Overall median procedural time was 23 min for first recanalization and 30 min for final recanalization. The cost per procedure was $6630 ± 1069 for CANADAPT, and $13,530 ± 2706 for SOLUMBRA techniques.

CONCLUSIONS

CANADAPT represents a standardized scientific-based approach to aspiration only thrombectomy intervention. This initial study demonstrates the safety, efficiency and efficacy of this technique for use in EVT.

Comparing Functional Outcomes and Safety Profiles of First-Line Aspiration Thrombectomy Versus Stentriever for Acute Basilar Artery Occlusion: Propensity Analysis of the PC-SEARCH Thrombectomy Registry

BACKGROUND

Aspiration catheters (ASPs) and stentriever thrombectomy devices have comparable safety and efficacy in anterior circulation ischemic strokes. However, there is lack of high-quality comparative data in acute basilar artery occlusions. Our objective is to compare the outcomes and safety of ASPs and stentriever devices in acute basilar artery occlusions.

METHODS

This is an analysis of the retrospectively established PC-SEARCH Thrombectomy (Posterior-Circulation Ischemic Stroke Evaluation: Analyzing Radiographic and Intraprocedural Predictors for Mechanical Thrombectomy) registry. Patients were dichotomized based on their first-line thrombectomy device (ASP and stentriever) and associated with their 90-day functional outcomes, intraprocedural metrics, and safety measures. Propensity analysis based on unequal baseline characteristics was performed. Consecutive patients with acute basilar artery occlusions who received mechanical thrombectomy were included from January 2015 to December 2021. Patients received either first-line contact aspiration or stentriever mechanical thrombectomy. Primary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale score of 0 to 3 and symptomatic intracranial hemorrhage, respectively. Secondary outcomes included puncture-recanalization times, first-pass recanalization rates, crossovers to other thrombectomy device, and neurological/hospital complications.

RESULTS

Five hundred eighteen patients were included in the registry, and a total of 383 patients were included (mean [SD] age, 65.5 [15] years; 228 [59%] men) in this analysis. Of these, 219 patients were first-line ASP while 164 patients received first-line stentriever devices. Median premorbid modified Rankin Scale was zero and median presenting National Institutes of Health Stroke Scale was 17 (interquartile range, 8-26). The proportion of favorable functional outcome was similar between the 2 techniques before (47.3% versus 42.5%; odds ratio, 1.22 [95% CI, 0.78-1.89]; P=0.38) and after propensity matching (odds ratio, 1.46 [95% CI, 0.85-2.49]; P=0.17). In our propensity-matched cohorts, puncture-recanalization times (18 versus 52 minutes; P<0.01) favored first-line ASP; however, first-pass recanalization rates (43.5% versus 44.5%; P=0.90) were similar between groups. First-line ASP was associated with higher rates of crossover (22% versus 6%; P<0.01), whereas stentriever was associated with higher rates of symptomatic intracranial hemorrhage (9.8% versus 3.4%; P=0.04).

CONCLUSIONS

First-line ASP and stentriever methods demonstrated similar functional outcome and recanalization rates. Stentriever methods were associated with higher rates of symptomatic intracranial hemorrhage, whereas ASPs were associated with higher rates of crossover to alternative technique in patients with acute basilar occlusions.

Mechanical Thrombectomy Access for All? Challenges in Increasing Endovascular Treatment for Acute Ischemic Stroke in the United States

Mechanical thrombectomy (MT) is the most effective treatment for selected patients with an acute ischemic stroke due to emergent large vessel occlusions (LVOs). There is an urgent need to identify and address challenges in access to MT to maximize the numbers of patients who can benefit from this treatment. Barriers in access to MT include delays in evaluation and accurate diagnosis of LVO leading to inappropriate triage, logistical delays related to availability of facilities and trained interventionalists, and financial hurdles that affect treatment reimbursement. Collection of regional data related to these barriers is critical to better understand current access gaps and a measurable access score to thrombectomy could be useful to plan local public health intervention.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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