Interventional Neurology最新文献

Objective: The middle cerebral artery (MCA) is the most commonly treated artery in mechanical thrombectomy stroke trials; however, there is no pragmatic agreement about the segmental anatomy and nomenclature utilized. It results in significant clinical-radiological dissociation and introduces bias in research trials. The purpose of the study is to review and compare angiographic anatomy with microsurgical anatomy literature of the MCA with emphasis on the discrepancy.

Methodology: Consecutive cerebral angiograms between January 2011 and March 2014 were retrospectively reviewed by endovascular surgical neuroradiologists. Information about the anatomy of the sphenoidal segment of the MCA classified as classic and non-classic pattern, the lenticulostriate artery takeoff pattern, and the course angulation of the sphenoidal segment were studied.

Results: A total of 500 patients, 886 cerebral angiograms, were reviewed. We found the classic pattern of the main trunk MCA bifurcation and a straight angulation course in less than half of the cases. The lenticulostriate arteries arose not only from the main trunk but also from its divisions in more than half of the cases.

Conclusion: It is important to corroborate our findings and to develop a pragmatic classification to accurately assess MCA occlusions from the radiological and clinical perspective.

Background: Platelet inhibitors are used to prevent thromboembolic complications related to neurovascular stenting (NVS) procedures. Despite substantial inter-individual variability of functional platelet inhibition, the value of platelet function tests (PFT) to assess inhibition remains controversial.

Objective: This study was conducted to compare differences in thromboembolic complication rates associated with NVS in platelet-inhibited patients with and without PFT. Clinical neurological outcomes were assessed by differences in the modified Rankin Scale (mRS).

Materials and methods: One hundred seventeen consecutive patients underwent elective NVS procedures within a 7-year period. All patients received aspirin and clopidogrel 8 days before the procedure. Fifty-two patients were treated without assessment of platelet inhibition, and 65 patients were tested for clopidogrel resistance. When clopidogrel resistance was revealed, corresponding patients were converted to ticagrelor. Changes in mRS and thromboembolic event rates were compared between the 2 cohorts.

Results: Thirty-five percent of patients from the cohort subjected to PFT tests showed inadequate platelet inhi-bition under clopidogrel and were converted to ticagrelor. Compared to the non-PFT test -cohort, neurological deficits were significantly reduced (12 vs. 0%; p = 0.009) and a lower number of thromboembolic events was found (12 vs. 3%; p > 0.05) within the test cohort.

Conclusion: PFT appears to identify patients with clopidogrel resistance prior to NVS procedures. When non-responders are converted to alternative platelet inhibitors, neurological outcomes and thromboembolic complication rates may improve. Consequently, this study provides preliminary evidence that PFT may be a useful clinical tool to enhance procedural safety and improve clinical outcomes in NVS procedures.

Objective: To examine outcomes for thrombectomy devices used for treatment of acute ischemic stroke (AIS) with middle cerebral artery (MCA) M2 segment emergent large vessel occlusion (ELVO) as the optimal device for such reperfusion is not clearly defined.

Methods: A retrospective cohort study of consecutive AIS patients with MCA M2 ELVO undergoing thrombectomy from 3 academic medical centers was conducted from October 1999 through June 2016. The patients were divided based on the device utilized. Multivariate analysis of associations between devices (stent retriever or aspiration only [manual or pump aspiration system]) was performed. Primary outcomes were good recanalization (i.e., modified thrombolysis in cerebral infarction score ≥2b) and a favorable modified Rankin scale (mRS) score (i.e. ≤2). The secondary outcome was symptomatic intracerebral hemorrhage (sICH).

Results: A total of 197 AIS patients underwent MCA M2 ELVO thrombectomy with either a stent retriever (n = 120) or aspiration only (n = 77). The aspiration-only group utilized either manual (n = 38) or pump aspiration (n = 39). Utilization of a stent retriever over manual aspiration is independently associated with higher odds of a favorable mRS score (OR = 3.2; 95% CI 1.02-9.7) and lower odds of sICH (OR = 0.09; 95% CI 0.03-0.31). Utilization of a stent retriever over a pump aspiration system is independently associated with higher odds of good recanalization (OR = 3.8; 95% CI 1.5-9.6). Utilization of a newer-generation pump aspiration catheter compared to a stent retriever resulted in similar rates of favorable mRS scores, sICH, successful recanalization, and mortality.

Conclusion: Utilization of a newer-generation pump aspiration catheter compared to a stent retriever resulted in similar outcomes, but worse outcomes were seen with the manual aspiration technique. These findings need to be confirmed with a large randomized trial utilizing stent retrievers and newer-generation pump aspiration systems.

First pass success (FPS) can be defined as in vitro retrieval of clot in a single pass during mechanical thrombectomy (MT) for acute large vessel occlusion (LVO). Despite advancements in MT technology, retrieval of fibrin-rich clots remains a challenge. Therefore, the effect of stent retriever length on FPS for fibrin-rich clots was investigated by using Solitaire^TM 6 × 40 versus 6 × 30 mm devices with a balloon guide catheter (BGC) or distal access catheter (DAC) and sheath, in an in vitro model of anterior circulation neurovascular anatomy. Additionally, vascular safety of the Solitaire^TM 6 × 40 versus 6 × 30 mm devices was evaluated in a porcine model for differences in: luminal thrombus, inflammation, endothelial coverage, fibrin deposits, smooth muscle cell loss, elastic lamina and adventitia disruption, intimal hyperplasia, and lumen reduction, at 0, 30, and 90 days post-treatment. In vitro overall FPS was measured as: Solitaire^TM 6 × 40 (95%) and Solitaire^TM 6 × 30 (67%). FPS for clot location in middle cerebral artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 100%; n = 8); (b) DAC with 088 sheath (6 × 40 mm: 83%; 6 × 30 mm: 33%; n = 12). FPS for clot location in internal carotid artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 80%; n = 11); (b) DAC with 088 sheath (6 × 40 mm: 100%; 6 × 30 mm: 67%; n = 10). Stent length had a significant effect (Fisher's exact test; p < 0.05) on FPS. In vivo evaluation in the porcine model showed no difference in vascular safety parameters between the Solitaire^TM 6 × 40 and 6 × 30 mm devices (p > 0.05) at all time points in the study. Longer stent retrievers may be safe and effective in improving FPS for fibrin-rich clots in in vitro and in vivo models of LVO.

Objective: To determine the safety and efficacy of flow reversal following proximal flow arrest as an embolic protection strategy for carotid angioplasty and stenting (CAS) with short-term follow-up.

Method: We performed a retrospective review of our CAS database for patients who underwent stent-supported carotid revascularization in the setting of acute/subacute stroke or TIA. We reviewed clinical and radiographic data during a 36-month period. Primary outcome was clinical evidence of ipsilateral stroke in the first 30 days. Secondary outcomes include clinical outcomes and sonographic and/or angiographic follow-up over 6 months, 6-month functional scale, and all-cause mortality.

Results: Fifty-five patients underwent CAS using flow reversal: 26 females and 29 males with a mean age of 69.7 years. Median time to treatment from index event was 3 days. 11% underwent stenting as part of hyperacute stroke therapy. Average luminal stenosis was 86%. The 9-Fr Mo.Ma device was used in combination with Penumbra aspiration in all cases. There were no ipsilateral strokes. Incidence of any ischemic event was 3.64%, but only 1 (1.82%) patient had a postoperative stroke. Clinical follow-up was available for 94.5%, while lesion follow-up was available for 73% of patients. Three patients had evidence of restenosis, but none were symptomatic. Luminal restenosis was ≤30% in all three. Median pre- and post-NIHSS were 1 and 1, respectively.

Conclusion: Flow reversal using the Mo.Ma device is a safe and effective strategy in preventing distal embolization during carotid artery revascularization.

Background: We aim to evaluate the speed and rates of reperfusion in tandem large vessel occlusion acute stroke patients undergoing upfront cervical lesion treatment (Neck-First: angioplasty and/or stent before thrombectomy) as compared to direct intracranial occlusion therapy (Head-First) in a large international multicenter cohort.

Methods: The Thrombectomy In TANdem Lesions (TITAN) collaboration pooled individual data of prospectively collected thrombectomy international databases for all consecutive anterior circulation tandem patients who underwent emergent thrombectomy. The co-primary outcome measures were rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b/3) and time from groin puncture to successful reperfusion.

Results: In total, 289 patients with tandem atherosclerotic etiology were included in the analysis (182 Neck-First and 107 Head-First patients). Except for differences in the Alberta Stroke Program Early CT Score (ASPECTS; median 8 [range 7-10] Neck-First vs. 7 [range 6-8] Head-First; p < 0.001) and cervical internal carotid artery (ICA) lesion severity (complete occlusion in 35% of the Neck-First vs. 57% of the Head-First patients; p < 0.001), patient characteristics were well balanced. After adjustments, there was no difference in successful reperfusion rates between the study groups (odds ratio associated with Neck-First: 1.18 [95% confidence interval, 0.60-2.17]). The time to successful reperfusion from groin puncture was significantly shorter in the Head-First group after adjustments (median 56 min [range 39-90] vs. 70 [range 50-102]; p = 0.001). No significant differences in the rates of full reperfusion, symptomatic hemorrhage, 90-day independence, or mortality were observed. Sensitivity analysis excluding patients with complete cervical ICA occlusion yielded similar results.

Conclusions: The upfront approach of the intracranial lesion in patients with tandem large vessel occlusion strokes leads to similar reperfusion rates but faster reperfusion as compared to initial cervical revascularization followed by mechanical thrombectomy. Controlled studies are warranted.

Background: Stent-assisted coiling (SAC) leads to significant changes in the vascular angle altering the bifurcation geometry and the hemodynamics at the bifurcation apex. It is believed that the stent alone exerts this effect, but other possible factors have not been studied.

Purpose: To study the factors contributing to angular remodeling following SAC of bifurcation aneurysms including the anatomical, stent-related, and coil-related factors.

Materials and methods: We reviewed 43 basilar and carotid bifurcation aneurysms treated by SAC using Neuroform EZ (n = 28), Enterprise (n = 8), and Lvis Jr. (n = 7) stents. The bifurcation angle between the mother and stented daughter vessel was measured in 4 settings: pretreatment, poststenting, postcoiling, and at delayed follow-up (6-12 months). The degree of stent-induced angular remodeling was calculated by subtracting the poststenting bifurcation angle from the pretreatment one, while the coil-induced angular remodeling was calculated as the difference between the postcoiling and poststenting bifurcation angle. The immediate postprocedural degree of angular remodeling is the sum of the stent- and coil-induced angular remodeling. We studied the effect of several factors including the pretreatment bifurcation angle, aneurysm site, diameter of parent vessel, stent type, stent length in the daughter vessel, postoperative actual in situ coil size, and packing density.

Results: The mean degree of stent-induced and coil-induced angular remodeling was 10.2 (0-47) and 4.53 (-7 to 30), respectively. The immediate postprocedural and delayed angular remodeling was 14.8 (-4 to 47) and 4.75 (-12 to 40), respectively. The degree of immediate remodeling was significantly affected by the actual in situ coil size (p = 0.017), and the pretreatment bifurcation angle (p = 0.024). Linear regression was carried out and the pretreatment bifurcation angle was defined as a predictor. The degree of delayed remodeling is significantly affected only by the pretreatment bifurcation angle (p = 0.011).

Conclusion: Immediate angular remodeling following SAC of bifurcation aneurysms can happen after stenting or coiling or both. This is the first study reporting the role of the coils as an additional factor beside the stent in inducing immediate angular changes; this effect is correlated to the size of the coils. The pretreatment bifurcation angle is the most consistent factor affecting the degree of both immediate and delayed angular remodeling.

Background: Studies have shown a lack of agreement of computed tomography perfusion (CTP) in the selection of acute ischemic stroke (AIS) patients for endovascular treatment.

Purpose: To demonstrate whether non-contrast computed tomography (CT) within 8 h of symptom onset is comparable to CTP imaging.

Methods: Prospective study of consecutive anterior circulation AIS patients with a National Institute of Health Stroke Scale (NIHSS) score > 7 presenting within 8 h of symptom onset with endovascular treatment. All patients had non-contrast CT, CT angiography, and CTP. The neuro-interventionalist was blinded to the results of the CTP and based the treatment decision using the Alberta Stroke Program Early CT score (ASPECTS). Baseline demographics, co-morbidities, and baseline NIHSS scores were collected. Outcomes were modified Rankin scale (mRS) score at discharge and in-hospital mortality. Good outcomes were defined as a mRS score of 0-2.

Results: 283 AIS patients were screened for the trial, and 119 were enrolled. The remaining patients were excluded for: posterior circulation stroke, no CTP performed, could not obtain consent, and NIHSS score < 7. Mean -NIHSS score at admission was 16.8 ± 3, and mean ASPECTS was 8.4 ± 1.4. There was no statistically significant correlation with CTP penumbra and good outcomes: 50 versus 47.8% with no penumbra present (p = 0.85). In patients without evidence of CTP penumbra, there was 22.5% mortality compared to 22.1% mortality in patients with a CTP penumbra. If ASPECTS ≥7, 64.6% had good outcome versus 13.3% if ASPECTS < 7 (p < 0.001). Patients with an ASPECTS ≥7 had 10% mortality versus 51.4% in patients with an ASPECTS < 7 (p < 0.001).

Conclusions: CTP penumbra did not identify patients who would benefit from endovascular treatment when patients were selected with non-contrast CT ASPECTS ≥7. There is no correlation of CTP penumbra with good outcomes or mortality. Larger prospective trials are warranted to justify the use of CTP within 6 h of symptom onset.

Background: The recently published multicenter randomized DAWN trial confirmed greater outcome benefit of endovascular therapy (ET) for anterior circulation large vessel occlusion ischemic stroke from 6 to 24 h from symptom onset compared to medical management in patients selected by advanced imaging with MRI or perfusion CT to identify mismatch between clinical deficit and infarct volume, which represents salvageable penumbra. The debate of CT over MRI is usually the potentially increase time consumption and the difficulty in establishing an adequate standardized workflow utilizing MRI during the hyperacute phase.

Purpose: While CT-based selection of patients is the current standard of care, we sought to determine the time impact of the alternative approach of MRI selection in the 0-12 h window.

Methods: In the MRI in Acute Management of Ischemic Stroke (MIAMIS) registry, we retrospectively analyzed 89 consecutive patients from January 2008 to January 2010 who presented with acute stroke symptoms with a National Institutes of Health Stroke Scale score ≥5 or aphasia within 0-12 h from symptom onset. The presence of penumbra was determined by MR perfusion-diffusion mismatch or clinical diffusion mismatch. Patients were stratified based on the presence of mismatch and clinical outcomes in patients who received ET. Imaging times were recorded.

Results: The MRI turnaround time was 95.5 ± 48.5 min. The total MRI time was 27.7 ± 12.8 min. Seventeen (19.1%) patients were found to have nonvascular etiology. Mismatch was found in 35 (48.6%) patients with acute ischemic stroke (AIS). Patients with nonvascular etiology were younger (55.7 vs. 65.6 years, p < 0.02), without any vessel occlusion or mismatch noticed in this group. We dichotomized the 39 AIS patients with vessel occlusion into two subgroups: these with mismatch and these without. Patients without mismatch were older (76.7 vs. 64.4 years, p < 0.05), more likely to have congestive heart failure (71.4 vs. 22%, p < 0.03), a higher total serum cholesterol level (196 vs. 156 mg/dL, p < 0.04), and medium to large lesions on diffusion-weighted imaging (DWI) (85.7 vs. 37.5%, p < 0.04).

Conclusions: Multimodality MRI screening for AIS symptoms for ET is feasible. Optimizing each center's protocol and the utilization of MRI with DWI only may be a time-saving alternative.

Background: Induced hypertension has been used to promote cerebral blood flow under vasospastic conditions although there is no randomised clinical trial to support its use. We sought to mathematically model the effects of vasospasm on the cerebral blood flow and the effects of induced hypertension.

Methods: The Anatomically Detailed Arterial Network (ADAN) model is employed as the anatomical substrate in which the cerebral blood flow is simulated as part of the simulation of the whole body arterial circulation. The pressure drop across the spastic vessel is modelled by inserting a specific constriction model within the corresponding vessel in the ADAN model. We altered the degree of vasospasm, the length of the vasospastic segment, the location of the vasospasm, the pressure (baseline mean arterial pressure [MAP] 90 mm Hg, hypertension MAP 120 mm Hg, hypotension), and the presence of collateral supply.

Results: Larger decreases in cerebral flow were seen for diffuse spasm and more severe vasospasm. The presence of collateral supply could maintain cerebral blood flow, but only if the vasospasm did not occur distal to the collateral. Induced hypertension caused an increase in blood flow in all scenarios, but did not normalise blood flow even in the presence of moderate vasospasm (30%). Hypertension in the presence of a complete circle of Willis had a marginally greater effect on the blood flow, but did not normalise flow.

Conclusion: Under vasospastic condition, cerebral blood flow varies considerably. Hypertension can raise the blood flow, but it is unable to restore cerebral blood flow to baseline.