Cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion: A case report

Cerebral hyperperfusion syndrome is a rare but serious complication after revascularization procedures for cerebrovascular diseases. Cerebral hyperperfusion syndrome can develop after treatment of acute ischemic stroke, including intravenous thrombolysis and endovascular treatment of large vessel occlusion. However, to the best of our knowledge, there are no previous reports describing cerebral hyperperfusion syndrome after endovascular treatment of medium vessel occlusion (eg, anterior cerebral artery A2/3 segment). We report a case of cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion. A 70-year-old woman with a history of hypertension and dyslipidemia was transferred by ambulance to our hospital because of immobility and slurred speech. She had mild right lower extremity paralysis, and her symptoms appeared improved compared with onset. She was diagnosed with cerebral infarction in the left frontal lobe. After hospitalization, her neurological symptoms worsened and she was referred to our department. We performed endovascular reperfusion therapy for left anterior cerebral artery A2 occlusion. Recanalization was achieved with residual stenosis. Despite the lack of complications associated with the procedure, the patient had prolonged disorientation, severe hemiplegia, and aphasia. Arterial spin labeling demonstrated hyperperfusion in the left anterior cerebral artery area. The symptoms gradually improved under strict blood pressure control. This report provides evidence that cerebral hyperperfusion syndrome can occur even after endovascular treatment for medium vessel occlusion. Arterial spin labeling was useful in detecting hyperperfusion.

Technical and clinical outcomes of thrombectomy in patients with acute medium vessel occlusion and large vessel occlusion; sub-analyses of Japan Trevo registry

BACKGROUND

Little is known about endovascular therapy (EVT) for patients with medium vessel occlusion (MeVO) and more work is needed to establish its efficacy and to understand hemorrhagic complications.

METHODS

We analyzed the Japan Trevo Registry, which enrolled patients with acute stroke who underwent EVT using Trevo Retriever alone or in combination with an aspiration catheter. The primary outcome was effective reperfusion, and the secondary outcome was modified Rankin scale 0-2 at 90 days. Safety outcomes, including intracranial hemorrhage (ICH), were evaluated using a subgroup analyses focused on any ICH.

RESULTS

Among 1041 registered patients, 1025 patients were analyzed. 253 patients had MeVOs, and the majority (89.3%) had middle cerebral artery segment 2 (M2). The median National Institutes of Health Stroke Scale scores at admission were 15 and 19 for the MeVO and LVO groups (p < 0.0001). The primary outcome was 88.9% in MeVO vs. 91.8% in LVO group: adjusted odds ratio (aOR) [95% confidence interval (CI)] 0.60 [0.35-1.03], p = 0.07, and the secondary outcome was 43.2% vs. 42.2%, and the aOR [95%CI] was 0.70 [0.48-1.002], p = 0.051. However, the incidence of any ICH was more prominent in MeVO than in LVO group (35.7% vs. 28.8%, aOR [95%CI] 1.54 [1.10-2.15], p = 0.01). In subgroup analyses, the incidences of any ICH in MeVO group were generally higher than those in LVO group.

CONCLUSIONS

The effective reperfusion rate did not differ significantly between MeVO and LVO groups. Future development of devices and treatments for MeVO with fewer hemorrhagic complications is desirable.

Use of the pRESET LITE thrombectomy device in combined approach for medium vessel occlusions: A multicenter evaluation

PURPOSE

Our purpose was to assess the efficacy and safety of the pRESET LITE stent retriever (Phenox, Bochum, Germany), designed for medium vessel occlusion (MeVO) in acute ischemic stroke (AIS) patients with a primary MeVO.

METHODS

We performed a retrospective analysis of the MAD MT Consortium, an integration of prospectively maintained databases at 37 academic institutions in Europe, North America, and Asia, of AIS patients who underwent mechanical thrombectomy with the pRESET LITE stent retriever for a primary MeVO. We subcategorized occlusions into proximal MeVOs (segments A1, M2, and P1) vs. distal MeVOs/DMVO (segments A2, M3-M4, and P2). We reviewed patient and procedural characteristics, as well as angiographic and clinical outcomes.

RESULTS

Between September 2016 and December 2021, 227 patients were included (50% female, median age 78 [65-84] years), of whom 161 (71%) suffered proximal MeVO and 66 (29%) distal MeVO. Using a combined approach in 96% of cases, successful reperfusion of the target vessel (mTICI 2b/2c/3) was attained in 85% of proximal MeVO and 97% of DMVO, with a median of 2 passes (IQR: 1-3) overall. Periprocedural complications rate was 7%. Control CT at day 1 post-MT revealed a hemorrhagic transformation in 63 (39%) patients with proximal MeVO and 24 (36%) patients with DMVO, with ECASS-PH type hemorrhagic transformations occurring in 3 (1%) patients. After 3 months, 58% of all MeVO and 63% of DMVO patients demonstrated a favorable outcome (mRS 0-2).

CONCLUSION

Mechanical thrombectomy using the pRESET LITE in a combined approach with an aspiration catheter appears effective for primary medium vessel occlusions across several centers and physicians.

Pretreatment parameters associated with hemorrhagic transformation among successfully recanalized medium vessel occlusions

Although pretreatment radiographic biomarkers are well established for hemorrhagic transformation (HT) following successful mechanical thrombectomy (MT) in large vessel occlusion (LVO) strokes, they are yet to be explored for medium vessel occlusion (MeVO) acute ischemic strokes. We aim to investigate pretreatment imaging biomarkers representative of collateral status, namely the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index, and their association with HT in successfully recanalized MeVOs. A prospectively collected registry of acute ischemic stroke patients with MeVOs successfully recanalized with MT between 2019 and 2023 was retrospectively reviewed. A multivariate logistic regression for HT of any subtype was derived by combining significant univariate predictors into a forward stepwise regression with minimization of Akaike information criterion. Of 60 MeVO patients successfully recanalized with MT, HT occurred in 28.3% of patients. Independent factors for HT included: diabetes mellitus history (p = 0.0005), CBV index (p = 0.0071), and proximal versus distal occlusion location (p = 0.0062). A multivariate model with these factors had strong diagnostic performance for predicting HT (area under curve [AUC] 0.93, p < 0.001). Lower CBV indexes, distal occlusion location, and diabetes history are significantly associated with HT in MeVOs successfully recanalized with MT. Of note, HIR was not found to be significantly associated with HT.

Follow-up infarct volume on fluid attenuated inversion recovery (FLAIR) imaging in distal medium vessel occlusions: the role of cerebral blood volume index

BACKGROUND

Distal medium vessel occlusions (DMVOs) contribute substantially to the incidence of acute ischemic strokes (AIS) and pose distinct challenges in clinical management and prognosis. Neuroimaging techniques, such as Fluid Attenuation Inversion Recovery (FLAIR) imaging and cerebral blood volume (CBV) index derived from perfusion imaging, have significantly improved our ability to assess the impact of strokes and predict their outcomes. The primary objective of this study was to investigate relationship between follow-up infarct volume (FIV) as assessed by FLAIR imaging in patients with DMVOs.

METHODS

This prospectively collected, retrospective reviewed cohort study included patients from two comprehensive stroke centers within the Johns Hopkins Medical Enterprise, spanning August 2018-October 2022. The cohort consisted of adults with AIS attributable to DMVO. Detailed imaging analyses were conducted, encompassing non-contrast CT, CT angiography (CTA), CT perfusion (CTP), and FLAIR imaging. Univariable and multivariable linear regression models were employed to assess the association between different factors and FIV.

RESULTS

The study included 79 patients with DMVO stroke with a median age of 69 years (IQR, 62-77 years), and 57% (n = 45) were female. There was a negative correlation between the CBV index and FIV in a univariable linear regression analysis (Beta =  - 16; 95% CI,  - 23 to  - 8.3; p < 0.001) and a multivariable linear regression model (Beta =  - 9.1 per 0.1 change; 95% CI,  - 15 to  - 2.7; p = 0.006). Diabetes was independently associated with larger FIV (Beta = 46; 95% CI, 16 to 75; p = 0.003). Additionally, a higher baseline ASPECTS was associated with lower FIV (Beta =  - 30; 95% CI,  - 41 to  - 20; p < 0.001).

CONCLUSION

Our findings underscore the CBV index as an independent association with FIV in DMVOs, which highlights the critical role of collateral circulation in determining stroke outcomes in this patient population. In addition, our study confirms a negative association of ASPECTS with FLAIR FIV and identifies diabetes as independent factor associated with larger FIV. These insights pave the way for further large-scale, prospective studies to corroborate these findings, thereby refining the strategies for stroke prognostication and management.

Reperfusion strategies in stroke with medium-to-distal vessel occlusion: a prospective observational study

INTRODUCTION

Medium vessel occlusion (MeVO) accounts for 30% of acute ischemic stroke cases. The risk/benefit profile of endovascular thrombectomy (EVT) and intravenous thrombolysis (IVT) or the combination of the two (bridging therapy (BT)) is still unclear in MeVO. Here, we compare reperfusion strategies in MeVO for clinical and radiological outcomes.

METHODS

This prospective single center study enrolled consecutive patients with AIS due to primary MeVO undergoing IVT, EVT, or BT at a comprehensive stroke center. Primary outcome was good functional status, defined as modified Rankin Scale (mRS) 0-2 at 3-month follow-up. Additional outcomes included mortality, successful recanalization, defined as mTICI ≥ 2b, stroke severity at discharge, and symptomatic intracerebral hemorrhage (sICH) according to SITS-MOST criteria. Logistic regression was modeled to define independent predictors of the primary outcome.

RESULTS

Overall, 180 consecutive people were enrolled (IVT = 59, EVT = 38, BT = 83), mean age 75. BT emerged as independent predictor of primary outcome (OR = 2.76, 95% CI = 1.08-7.07) together with age (OR = 0.94, 95% CI = 0.9-0.97) and baseline NIHSS (OR = 0.88, 95% CI = 0.81-0.95). BT associated with a 20% relative increase in successful recanalization compared to EVT (74.4 vs 56.4%, p = 0.049). Rates of sICH (1.1%) and procedural complications (vasospasm 4.1%, SAH in 1.7%) were very low, with no difference across groups.

DISCUSSION

BT may carry a higher chance of good functional outcome compared to EVT/IVT only in people with AIS due to MeVO, with marginally higher rates of successful recanalization. Randomized trials are needed to define optimal treatment tailoring for MeVO.

Clinical outcome after thrombectomy in patients with MeVO stroke: importance of clinical and technical factors

BACKGROUND AND AIMS

Whereas high-level evidence has been proven for safety and efficacy of endovascular treatment (EVT) in large vessel occlusion (LVO) stroke, the evidence for EVT in medium vessel occlusion (MeVO) in both sexes and different age groupremains to be answered. The aim of this study was to evaluate the importance of clinical and technical parameters, focusing on sex, age and EVT procedural factors, on functional outcome in primary MeVO (pMeVO) strokes.

METHODS

144 patients with pMeVO in the MCA territory from the Oslo Acute Reperfusion Stroke Study (OSCAR) were included. Clinical and radiological data were collected including 90-day mRS follow-up.

RESULTS

Successful reperfusion with modified thrombolysis in cerebral infarction (mTICI) ≥ 2b was achieved in 123 patients (84%). Good functional outcome (mRS ≤ 2) at 90-day follow-up was achieved in 84 patients (61.8%). Two or more passes with stent retriever was associated with increased risk of SAH, poor mTICI and poor functional outcome. In average, women had 62 min longer ictus to recanalization time compared to men. Age over 80 years was significantly associated with poor outcome and death.

CONCLUSION

In pMeVO patients, TICI score and number of passes with stent retriever were the main technical factors predicting mRS ≤ 2. Good clinical outcome occurred almost twice as often in patients under 80 years of age compared to patients over 80 years. Women with MeVO strokes had significant longer time from ictus to recanalization; however, this did not affect the clinical outcome.

Safety and efficacy of endovascular thrombectomy for primary and secondary MeVO

BACKGROUND

Medium-vessel occlusions (MeVO) are emerging as a new target for endovascular treatment (EVT). Primary MeVO occur de novo, while secondary MeVO arise from large vessel occlusion (LVO) through clot migration or fragmentation - spontaneously, following intravenous thrombolysis or EVT. We aimed to evaluate efficacy and safety of EVT in primary and EVT-induced secondary MeVO.

METHODS

Retrospective single-center study on consecutive EVT-treated acute ischemic stroke, from 2019-to-2021. We considered: (1) exclusive-LVO, patients with LVO and - in case of residual distal occlusion - no rescue endovascular procedure; (2) primary MeVO: initial A2, A3, M2 non-dominant, M3, P2, P3 occlusions; (3) EVT-induced secondary MeVO, presenting LVO with subsequent (treated) EVT-induced MeVO. We compared (univariable/multivariable logistic regression) EVT efficacy (eTICI≥2b, 3-month modified Rankin Scale [mRS] 0-2) and safety (EVT-complications [vessel dissection, perforation, persistent-SAH], symptomatic ICH) in all MeVO versus exclusive-LVO, primary MeVO versus exclusive-LVO, EVT-induced secondary MeVO versus exclusive-LVO and EVT-induced secondary MeVO versus primary MeVO.

RESULTS

We included 335 patients: 221 (66.0 %) exclusive-LVO and 114 (34.0 %) MeVO (55 [48.2 %] primary, 59 [51.8 %] secondary). Compared to exclusive-LVO, primary MeVO had higher rates of EVT complications (aOR 3.77 [95%CI 1.58-9.00],p=0.003), lower rates of eTICI≥2b (aOR 0.32 [95%CI 0.12-0.88],p=0.027) and mRS 0-2 (aOR 0.28 [95%CI 0.13-0.63],p=0.002). EVT-induced secondary MeVO had no major differences in efficacy and safety outcomes compared to exclusive-LVO, but a better mRS 0-2 (aOR 8.00 [95%CI 2.12-30.17],p=0.002) compared to primary MeVO.

CONCLUSIONS

Primary and EVT-induced secondary MeVO showed different safety/efficacy EVT-related profiles. Dedicated randomized data are needed to identify the best acute reperfusion strategy in the two categories.

Pretreatment CTP Collateral Parameters Predict Good Outcomes in Successfully Recanalized Middle Cerebral Artery Distal Medium Vessel Occlusions

BACKGROUND/PURPOSE

Distal medium vessel occlusions (DMVOs) account for a large percentage of vessel occlusions resulting in acute ischemic stroke (AIS) with disabling symptoms. We aim to assess whether pretreatment quantitative CTP collateral status (CS) parameters can serve as imaging biomarkers for good clinical outcomes prediction in successfully recanalized middle cerebral artery (MCA) DMVOs.

METHODS

We performed a retrospective analysis of consecutive patients with AIS secondary to primary MCA-DMVOs who were successfully recanalized by mechanical thrombectomy (MT) defined as modified thrombolysis in cerebral infarction (mTICI) 2b, 2c, or 3. We evaluated the association between the CBV index and HIR independently with good clinical outcomes (modified Rankin score 0-2) using Spearman rank correlation, logistic regression, and ROC analyses.

RESULTS

From 22 August 2018 to 18 October 2022 8/22/2018 to 10/18/2022, 60 consecutive patients met our inclusion criteria (mean age 71.2 ± 13.9 years old [mean ± SD], 35 female). The CBV index (r = -0.693, p < 0.001) and HIR (0.687, p < 0.001) strongly correlated with 90-day mRS. A CBV index ≥ 0.7 (odds ratio, OR, 2.27, range 6.94-21.23 [OR] 2.27 [6.94-21.23], p = 0.001)) and lower likelihood of prior stroke (0.13 [0.33-0.86]), p = 0.024)) were independently associated with good outcomes. The ROC analysis demonstrated good performance of the CBV index in predicting good 90-day mRS (AUC 0.73, p = 0.003) with a threshold of 0.7 for optimal sensitivity (71% [52.0-85.8%]) and specificity (76% [54.9-90.6%]). The HIR also demonstrated adequate performance in predicting good 90-day mRS (AUC 0.77, p = 0.001) with a threshold of 0.3 for optimal sensitivity (64.5% [45.4-80.8%]) and specificity (76.0% [54.9-90.6%]).

CONCLUSION

A CBV index ≥ 0.7 may be independently associated with good clinical outcomes in our cohort of AIS caused by MCA-DMVOs that were successfully treated with MT. Furthermore, a HIR < 0.3 is also associated with good clinical outcomes. This is the first study of which we are aware to identify a CBV index threshold for MCA-DMVOs.

Willingness to randomize primary medium vessel occlusions for endovascular treatment

BACKGROUND AND PURPOSE

Patients with acute ischemic stroke due to medium vessel occlusion (MeVO) make up a substantial part of the acute stroke population, though guidelines currently do not recommend endovascular treatment (EVT) for them. A growing body of evidence suggests that EVT is effective in MeVOs, including observational data but no randomized studies. We aimed to explore willingness of physicians worldwide to randomize MeVO stroke patients into a hypothetical trial comparing EVT in addition to best medical management versus best medical management only.

METHODS

In an international cross-sectional survey among stroke physicians, participants were presented with 4 cases of primary MeVOs (6 scenarios each). Each subsequent scenario changed one key patient characteristic compared to the previous one, and asked survey participants whether they would be willing to randomize the described patient. Overall, physician- and scenario-specific decision rates were calculated. Multivariable logistic regression with clustering by respondent was performed to assess factors influencing the decision to randomize.

RESULTS

Overall, 366 participants (56 women) from 44 countries provided 8784 answers to 24 MeVO case scenarios. The majority of responses (78.3%) were in favor of randomizing. Most physicians were willing to accept patients transferred for EVT from a primary center (82%) and the majority of these (76.5%) were willing to randomize these patients after transfer. Patient age > 65 years, A3 occlusion, small core volume, and patient intravenous alteplase eligibility significantly influenced the physician's decision to randomize (adjOR 1.24, 95%CI 1.13-1.36; adjOR 1.17, 95%CI 1.01-1.34; adjOR 0.98, 95%CI 0.97-0.99 and adjOR 1.38, 95%CI 1.21-1.57, respectively).

CONCLUSIONS

Most physicians in this survey were willing to randomize acute MeVO stroke patients irrespective of patient characteristics into a trial comparing EVT in addition to best medical management versus best medical management only, suggesting there is clinical equipoise.

Increased Rate of Successful First Passage Recanalization During Mechanical Thrombectomy for M2 Occlusion

BACKGROUND

Mechanical thrombectomy (MT) is the standard of care for the treatment of acute ischemic stroke (AIS) caused by anterior circulation large-vessel occlusion. However, the true safety and efficacy of MT in medium-size vessel occlusions such as the M2 segment of the middle cerebral artery have yet to be completely defined. In this study, we analyze the safety and efficacy of MT in M2 occlusions compared with M1 occlusions.

METHODS

A retrospective analysis was performed of patients with AIS secondary to M1 and M2 occlusions between 2011 and 2018. The inclusion criteria were 1) AIS secondary to M1 or M2 occlusion, 2) MT performed by stentrieval technique alone, aspiration technique, or combined stentrieval-aspiration techniques. Basic patient characteristics, number of passages, first passage recanalization success (≥TICI [Thrombolysis in Cerebral Ischemia] grade 2b), total recanalization success, hemorrhagic complications (including intracerebral hemorrhage [ICH] and subarachnoid hemorrhage), and clinical outcomes were compared between both groups.

RESULTS

Two hundred and sixty patients met the inclusion criteria; 171 patients had M1 occlusion versus 89 with M2 occlusion. First passage recanalization success rate was significantly higher in the M2 group (55.1% vs. 39.2%; P = 0.015). Total recanalization success rate was higher in the M2 group but did not reach significance (83% vs. 75%; P = 0.128). Subarachnoid hemorrhage rate was significantly higher in the M2 group (25% vs. 12%; P = 0.010) but there was no difference for ICH complications (14.6% vs. 16.4%; P = 0.711).

CONCLUSIONS

MT for M2 occlusions has similar overall efficacy to that for M1 occlusions, but with higher first-pass successful recanalization rates. MT for M2 occlusions has a higher risk of associated subarachnoid hemorrhage.