Silent cerebral ischaemia: hidden fingerprints of invasive medical procedures

Clinical and subclinical microemboli following neuroangiography in children

BACKGROUND

To assess the frequency, imaging appearances, and risk factors of brain microemboli following pediatric neuroangiography, as assessed by early diffusion-weighted MRI imaging (DWI).

METHODS

This single-center, retrospective analysis investigated early DWI post-pediatric neuroangiography. Patients aged 0-18 years who had diagnostic neuroangiography and DWI within a week postprocedure were included. Data on clinical and procedural parameters and MRI findings were recorded. Univariate and multivariate analyses were performed on the following risk factors: age, weight, vasculopathy, antiplatelet drug use, access type, intraprocedural heparin, procedure duration, neck arteries catheterized, and angiographic runs. A p-value<0.05 indicated statistical significance.

RESULTS

Eighty-two children were included (40.2% female), mean age 10.1±4.5 years (range: 7 months-17 years). There were no intraprocedural thromboembolic complications recognized. DWI positivity was seen following 3.6% (3/82) procedures: two with transient symptoms, and one instance of silent microemboli. There were no territorial infarcts or clinical stroke. Children with underlying vasculopathy had a higher risk of microemboli from angiography than children without vasculopathy (OR 31.6, p=0.02), and the OR of microemboli following transradial angiography was 79.1 (p=0.005) as compared with transfemoral angiography. Univariate and multivariate analysis showed a significant association between microemboli and number of angiographic runs (p=0.004). Follow-up MRI in all three patients showed no residual abnormal signal.

CONCLUSIONS

Cerebral microemboli are unusual following uncomplicated neuroangiography in children. However, in the presence of underlying vasculopathy and with transradial technique, the incidence approaches that reported in the adult literature. An increased association with the number of angiographic runs is an important and controllable factor.

Comparison of Outcomes Between Right and Left Upper Extremity Access in Endovascular Aortic Repair for Patients with Thoracoabdominal and Abdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis

Traditionally, left-sided upper extremity (LUE) access has been preferred in patients undergoing endovascular aortic repair (EVAR) to manage aortic aneurysms and decrease the risk of cerebrovascular adverse events. Recently, right-sided upper extremity access (RUE) has gained popularity owing to its greater maneuverability and ergonomics. However, synthesized data comparing the safety and efficacy of RUE and LUE accesses are limited. A comprehensive literature search was conducted on various databases from inception to September 2023 to retrieve all studies that compared RUE and LUE access in EVAR. Data on stroke, 30-day mortality, technical success, access-site complications, total time required for fluoroscopy, and contrast agent requirement were extracted, pooled, and analyzed. Forest plots were generated using a random-effects model on review manager by pooling the risk ratios (RRs) and standard mean differences (SMDs). Ten observational studies with a total of 3994 patients were included in our analysis with 1186 patients in the RUE and 2808 patients in the LUE access groups. EVAR using RUE access was associated with a significantly lower amount of contrast agent requirement than the LUE access group [SMD, -0.23; 95% confidence interval (CI), -0.45 to -0.02; P = 0.03]. There was no significant difference between the 2 groups in terms of the risk of stroke (RR, 1.62; 95% CI, 0.81-3.22; P = 0.17), 30-day mortality (RR, 1.42; 95% CI, 0.50-4.06; P = 0.51), rate of technical success (RR, 0.98; 95% CI, 0.95-1.01; P = 0.18), risk of access-site complications (RR, 1.00; 95% CI, 0.72-1.39; P = 0.99), and total time required for fluoroscopy (SMD, 0.07; 95% CI, -0.39 to 0.26; P = 0.69). The use of RUE access in EVAR appears to be comparable to LUE access in terms of the risk of stroke, access-related complications, all-cause mortality, technical success rate, and fluoroscopy duration. The RUE group required a lower volume of contrast agent.

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.

Frequency and Pattern of MRI Diffusion Restrictions after Diagnostic Catheter Neuroangiography

(1) Background: We investigated the frequency, location, and lesion size of diffusion restrictions (DR) in magnetic resonance imaging (MRI) of asymptomatic patients after diagnostic angiography and assessed risk factors for their occurrence. (2) Methods: We analyzed diffusion-weighted images (DWI) of 344 patients undergoing diagnostic angiographies in a neuroradiologic center. Only asymptomatic patients who received a magnetic resonance imaging (MRI) examination within seven days after the angiography were included. (3) Results: Asymptomatic infarcts on DWI were identified in 17% of the cases after diagnostic angiography. In these 59 patients, a total of 167 lesions were noted. The diameter of the lesions was 1-5 mm in 128 lesions, and 5-10 mm in 39 cases. Dot-shaped diffusion restrictions were found most frequently (n = 163, 97.6%). None of the patients had neurological deficits during or after angiography. Significant correlations were found between the occurrence of lesions and patient age (p < 0.001), history of atherosclerosis (p = 0.014), cerebral infarction (p = 0.026), or coronary heart disease/heart attack (p = 0.027); and the amount of contrast medium used (p = 0.047) and fluoroscopy time (p = 0.033). (4) Conclusions: With an incidence of 17%, we observed a comparatively high risk for asymptomatic cerebral ischemia after diagnostic neuroangiography. Further measures to reduce the risk of silent embolic infarcts and improve the safety of neuroangiography are warranted.

Incidence, Clinical Significance, and Longitudinal Signal Characteristics of Ischemic Lesions Related to Diagnostic Cerebral Catheter Angiography

PURPOSE

Cerebral DSA is a routine procedure with few complications. However, it is associated with presumably clinically inapparent lesions detectable on diffusion-weighted MRI imaging (DWI lesions). However, there are insufficient data regarding incidence, etiology, clinical relevance, and longitudinal development of these lesions. This study prospectively evaluated subjects undergoing elective diagnostic cerebral DSA for the occurrence of DWI lesions, potentially associated clinical symptoms and risk factors, and longitudinally monitored the lesions using state-of-the-art MRI.

MATERIALS AND METHODS

Eighty-two subjects were examined by high-resolution MRI within 24 h after elective diagnostic DSA and lesion occurrence was qualitatively and quantitatively evaluated. Subjects' neurological status was assessed before and after DSA by clinical neurological examination and a perceived deficit questionnaire. Patient-related risk factors and procedural DSA data were documented. Subjects with lesions received a follow-up MRI and were questioned for neurological deficits after a median of 5.1 months.

RESULTS

After DSA, 23(28%) subjects had a total of 54 DWI lesions. Significantly associated risk factors were number of vessels probed, intervention time, age, arterial hypertension, visible calcified plaques, and less examiner experience. Twenty percent of baseline lesions converted to persistent FLAIR lesions at follow-up. After DSA, none of the subjects had a clinically apparent neurological deficit. Self-perceived deficits were nonsignificantly higher at follow-up.

CONCLUSION

Cerebral DSA is associated with a considerable number of postinterventional lesions, some persisting as scars in brain tissue. Presumably because of the small lesion size and inconsistent location, no clinically apparent neurological deficits have been observed. However, subtle self-perceived changes may occur. Therefore, special attention is needed to minimize avoidable risk factors.

Isolated Internuclear Ophthalmoplegia as an Embolic Complication of Transcatheter Aortic Valve Implantation

An 83-year-old male developed horizontal diplopia immediately following elective transfemoral transcatheter aortic valve implantation (TAVI). On right gaze, left eye adduction was impaired while there was horizontal nystagmus of the abducting right eye, representative of internuclear ophthalmoplegia (INO). The remainder of the neurological examination was normal. Computer tomography (CT) imaging of the brain and CT angiogram of the head and neck were normal. Magnetic resonance imaging (MRI) of the brain showed five small foci of restricted diffusion affecting both the anterior and posterior circulation bilaterally. One such tiny infarct was seen in the left parasagittal upper pontine tegmentum and was attributed to his presentation. While all symptoms rapidly improved, minimal residual signs of INO were still detectable at the six-month follow-up. Isolated intra-nuclear ophthalmoplegia is a rare stroke syndrome and an unusual cardio-embolic complication of minimally invasive cardiac procedures. TAVI is an increasingly popular technique, although has been associated with a higher incidence of micro-embolic cerebrovascular events evident on MRI than surgical repairs. While the use of embolic protection devices has high-quality evidence in reducing the burden of these usually silent cerebrovascular events, their role in preventing long-term neurocognitive sequala has not been demonstrated.

The Intersection of Aging and Lung Transplantation: its Impact on Transplant Evaluation, Outcomes, and Clinical Care

Purpose

Older adults (age ≥ 65 years) are the fastest growing age group undergoing lung transplantation. Further, international consensus document for the selection of lung transplant candidates no longer suggest a fixed upper age limit. Although carefully selected older adults can derive great benefit, understanding which older adults will do well after transplant with improved survival and health-related qualiy of life is key to informed decision-making. Herein, we review the epidemiology of aging in lung transplantation and its impact on outcomes, highlight selected physiological measures that may be informative when evaluating and managing older lung transplant patients, and identify directions for future research.

Recent Findings

In general, listing and transplanting older, sicker patients has contributed to worse clinical outcomes and greater healthcare use. Emerging evidence suggest that measures of physiological age, such as frailty, body composition, and neurocognitive and psychosocial function, may better identify risk for poor transplant outcomes than chronlogical age.

Summary

The evidence base to inform transplant decision-making and improvements in care for older adults is small but growing. Multipronged efforts at the intersection of aging and lung transplantation are needed to improve the clinical and patient centered outcomes for this large and growing cohort of patients. Future research should focus on identifying novel and ideally modifiable risk factors for poor outcomes specific to older adults, better approaches to measuring physiological aging (e.g., frailty, body composition, neurocognitive and psychosocial function), and the underlying mechanisms of physiological aging. Finally, interventions that can improve clinical and patient centered outcomes for older adults are needed.

Cerebral embolisation during transcatheter edge-to-edge repair of the mitral valve with the MitraClip system: a prospective, observational study

BACKGROUND

New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to 86% of patients after transcatheter edge-to-edge repair of the mitral valve (TEER-MV). Knowledge of the exact procedural step(s) that carry the highest risk for cerebral embolisation may help to further improve the procedure.

AIMS

The aim of this study was to identify the procedural step(s) that are associated with an increased risk of cerebral embolisation during TEER-MV with the MitraClip system. Furthermore, the risk of overt stroke and silent brain ischaemia after TEER-MV was assessed.

METHODS

In this prospective, pre-specified observational study, all patients underwent continuous transcranial Doppler examination during TEER-MV to detect microembolic signals (MES). MES were assigned to specific procedural steps: (1) transseptal puncture and placement of the guide, (2) advancing and adjustment of the clip in the left atrium, (3) device interaction with the MV, and (4) removal of the clip delivery system and the guide. Neurological examination using the National Institutes of Health Stroke Scale (NIHSS) and cerebral MRI were performed before and after TEER-MV.

RESULTS

Fifty-four patients were included. The number of MES differed significantly between the procedural steps with the highest numbers observed during device interaction with the MV. Mild neurological deterioration (NIHSS ≤3) occurred in 9/54 patients. New ischaemic lesions were detected in 21/24 patients who underwent MRI. Larger infarct volume was significantly associated with neurological deterioration.

CONCLUSIONS

Cerebral embolisation is immanent to TEER-MV and predominantly occurs during device interaction with the MV. Improvements to the procedure may focus on this procedural step.

Asymptomatic Stroke in the Setting of Percutaneous Non-Coronary Intervention Procedures

Advancements in clinical management, pharmacological therapy and interventional procedures have strongly improved the survival rate for cardiovascular diseases (CVDs). Nevertheless, the patients affected by CVDs are more often elderly and present several comorbidities such as atrial fibrillation, valvular heart disease, heart failure, and chronic coronary syndrome. Standard treatments are frequently not available for “frail patients”, in particular due to high surgical risk or drug interaction. In the past decades, novel less-invasive procedures such as transcatheter aortic valve implantation (TAVI), MitraClip or left atrial appendage occlusion have been proposed to treat CVD patients who are not candidates for standard procedures. These procedures have been confirmed to be effective and safe compared to conventional surgery, and symptomatic thromboembolic stroke represents a rare complication. However, while the peri-procedural risk of symptomatic stroke is low, several studies highlight the presence of a high number of silent ischemic brain lesions occurring mainly in areas with a low clinical impact. The silent brain damage could cause neuropsychological deficits or worse, a preexisting dementia, suggesting the need to systematically evaluate the impact of these procedures on neurological function.

Magnetic particle imaging for artifact-free imaging of intracranial flow diverter stents: A phantom study

PURPOSE

Magnetic Particle Imaging (MPI) is a new, background- and radiation-free tomographic imaging method that enables near real-time imaging of superparamagnetic iron-oxide nanoparticles (SPIONs) with high temporal and spatial resolution. This phantom study aims to investigate the potential of MPI for visualization of the stent lumen in intracranial flow diverters (FD).

METHODS

Nitinol FD of different dimensions (outer diameter: 3.5 mm, 4.0 mm, 5.5 mm; total length: 22-40 mm) were scanned in vascular phantoms in a custom-built MPI scanner (in-plane resolution: ~ 2 mm, field of view: 65 mm length, 29 mm diameter). Phantoms were filled with diluted (1:50) SPION tracer agent Ferucarbotran (10 µmol (Fe)/ml; NaCL). Each phantom was measured in 32 different projections (overall acquisition time per image: 3200 ms, 5averages). After image reconstruction from raw data, two radiologists assessed image quality using a 5-point Likert scale. The signal intensity profile was measured using a semi-automatic evaluation tool.

RESULTS

MPI visualized the lumen of all FD without relevant differences between the stented vessel phantom and the reference phantom. At 3.5 mm image quality was slightly inferior to the larger diameters. The FD themselves neither generated an MPI signal nor did they lead to relevant imaging artifacts. Ratings of both radiologists showed no significant difference, interrater reliability was good (ICC 0.84). A quantitative evaluation of the signal intensity profile did not reveal any significant differences (p > 0.05) either.

CONCLUSION

MPI visualizes the lumen of nitinol FD stents in vessel phantoms without relevant stent-induced artifacts.

The effect of complex vascular anatomy on silent new ischemic cerebral lesions in carotid artery stenting procedures (from the COMPLEX-CAS Trial)

BACKGROUND

Carotid artery stenting is a minimally invasive, durable alternative treatment option, which is an alternative to the reference method, carotid endarterectomy, for patients with carotid artery stenosis; however, silent new ischemic cerebral lesions (SNICLs) after carotid artery stenting remain as a matter of concern. Hence, we aimed to assess the effect of complex vascular anatomy on silent new ischemic cerebral lesions in carotid artery stenting procedures.

METHODS

We prospectively evaluated 122 patients (mean age: 69.5 ± 7.1 years, male:83) who underwent carotid artery stenting for carotid artery revascularization. The patients having symptomatic transient ischemic attack or stroke after carotid artery stenting were excluded. The presence of a new hyperintense lesions on diffusion-weighted imaging without any neurological findings was considered as the SNICL. Patients were classified into two groups as DWI-positive and DWI-negative patients.

RESULTS

Among the study population, 32 patients (26.2%) had SNICLs. The DWI-positive group had a significantly higher common carotid artery (CCA)-internal carotid artery (ICA) angle, older age, more frequent history of stroke, a higher proportion of type III aortic arch, and longer fluoroscopy time than the DWI-negative group. High CCA-ICA angle was identified as one of the independent predictors of SNICL (OR (odds ratio) = 1.103 95%CI (confidence interval): (1.023-1.596); p = 0.034), and CCA-ICA angle higher than 34.5 degrees predicted SNICL with a sensitivity of 62.5% and a specificity of 62.2% (area under the curve: 0.680; 95% CI: 0.570 to 0.789; p = 0.003).

CONCLUSIONS

The higher CCA-ICA angle may predict pre-procedure SNICL risk in carotid artery stenting and may have clinical value in the management of patients with carotid artery stenosis.

Multicenter global early feasibility study to evaluate total endovascular arch repair using three-vessel inner branch stent-grafts for aneurysms and dissections

OBJECTIVE

We evaluated the outcomes of total endovascular aortic arch repair using three-vessel inner branch stent-grafts for aneurysms and chronic dissections.

METHODS

We reviewed the clinical data and outcomes of consecutive patients treated by total endovascular aortic arch repair at eight academic centers using three-vessel inner branch stent-grafts (William Cook Europe, Bjaeverskov, Denmark) from 2016 to 2019. All patients received three-vessel designs with two antegrade and one retrograde inner branch, which was used to incorporate the innominate, left common carotid, and left subclavian arteries. The antegrade inner branches were accessed via a carotid or an upper extremity approach. A preloaded catheter was used for access to the retrograde left subclavian artery branch via a transfemoral approach. The endpoints were technical success, mortality, major adverse events, any stroke (minor or major) or transient ischemia attack, secondary interventions, target vessel patency, target vessel instability, aneurysm-related mortality, and patient survival.

RESULTS

A total of 39 patients (31 men [79%]; mean age, 70 ± 7 years) had undergone treatment of 14 degenerative (36%) and 25 chronic (64%) postdissection arch aneurysms. The clinical characteristics included American Society of Anesthesiologists class ≥III in 28 patients (95%) and previous median sternotomy for ascending aortic repair in 28 patients (72%). The technical success rate was 100%. Two patients had died in-hospital or within 30 days (5%), and two patients had experienced a stroke (one minor). The combined mortality and any stroke rate was 8% (n = 3). Major adverse events occurred in 10 patients (26%), including respiratory failure in 4 (10%) and estimated blood loss >1 L, myocardial infarction, and acute kidney injury in 2 patients each (5%). The median follow-up was 3.2 months (interquartile range, 1-14 months). Of the 39 patients, 12 (31%) required secondary interventions to treat vascular access complications in 5, endoleak in 6 (three type II, one type Ic, one type Ia/Ib, one type IIIa), and target vessel stenosis in 1 patient. At 1 year, the primary and secondary patency rates and freedom from target vessel instability were 95% ± 5%, 100%, and 91% ± 5%, respectively. Freedom from aortic-related mortality and patient survival was 94% ± 4% and 90% ± 6%, respectively.

CONCLUSIONS

The findings from the present multicenter global experience have demonstrated the technical feasibility and safety of total endovascular aortic arch repair for aneurysms and chronic dissections using three-vessel inner branch stent-grafts. The mortality and stroke rates compare favorably with those after open surgical repair in a higher risk group of patients. However, the rate of secondary interventions was high (31%), emphasizing need for greater experience and longer follow-up.

Iatrogenic Diffusion-Weighted Imaging Lesions: What Is Their Impact and How Can It Be Measured?

Infarct volume in acute ischemic stroke is closely linked with clinical outcome, with larger infarct volumes being associated with a worse prognosis. Small iatrogenic infarcts, which can occur as a result of surgical or endovascular procedures, are often only seen on diffusion-weighted MR imaging. They often do not lead to any overtly appreciable clinical deficits, hence the term covert or silent infarcts. There is relative paucity of data on the clinical impact of periprocedural hyperintense diffusion-weighted MR imaging lesions, partly because they commonly remain undiagnosed. Clearly, a better understanding of iatrogenic periprocedural diffusion-weighted MR imaging lesions and their clinical significance is needed. In this article, we describe the current limitations of our understanding of the significance of iatrogenic diffusion-weighted MR imaging lesions using exemplary data from the ENACT trial (Safety and Efficacy of NA-1 in Patients With Iatrogenic Stroke After Endovascular Aneurysm Repair) and outline a framework for how to investigate their clinical impact.

Semiautomatic cerebrovascular territory mapping based on dynamic ASL MR angiography without vessel-encoded labeling

PURPOSE

Characterizing vessel territories can provide crucial information for evaluation of cerebrovascular disorders. In this study, we present a novel postprocessing pipeline for vascular territorial imaging of cerebral arteries based on a noncontrast enhanced time-resolved 4D magnetic resonance angiography (MRA).

METHODS

Eight healthy participants, 1 Moyamoya patient, and 1 arteriovenous malformations patient were recruited. Territorial segmentation and relative blood flow rate calculations of cerebral arteries including left and right middle cerebral arteries and left and right posterior cerebral arteries were carried out based on the 4D MRA-derived arterial arrival time maps of intracranial vessels.

RESULTS

Among healthy young subjects, the average relative blood flow rate values corresponding to left and right middle cerebral arteries and left and right posterior cerebral arteries were 35.9 ± 5.9%, 32.9 ± 7.5%, 15.4 ± 3.8%, and 15.9 ± 2.5%, respectively. Excellent agreement was observed between relative blood flow rate values obtained from the proposed 4D MRA-based method and reference 2D phase contrast MRI. Abnormal cerebral circulations were visualized and quantified on both patients using the developed technique.

CONCLUSION

The vascular territorial imaging technique developed in this study allowed for the generation of territorial maps with user-defined level of details within a clinically feasible scan time, and as such may provide useful information to assess cerebral circulation balance in different pathologies.

Brain magnetic resonance imaging in adult survivors of extracorporeal membrane oxygenation

Despite the common occurrence of neurologic complications in patients with extracorporeal membrane oxygenation (ECMO), data on magnetic resonance imaging (MRI) findings in adult ECMO are limited. We aimed to describe the MRI findings of patients after ECMO cannulation. Records of patients who underwent ECMO from September 2017 to June 2019 were reviewed. MRI studies were performed using multiplanar sequences consisting of T1-, T2-weighted, fluid attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and susceptibility weighted images (SWI). Of the 78 adult patients who underwent ECMO, 26 (33%) survived. Of 26, eight patients (31%) had MRI studies, with a median age of 47 years (interquartile range [IQR]: 25-57). The median ECMO support time was 8 days (IQR: 4-25) and the median time from decannulation to MRI was 12 days (IQR: 1-34). Five (63%) of eight patients had ischemic infarcts; 4 (50%) had cerebral microhemorrhage; 2 (25%) had intracranial hemorrhage; and 1 (13%) had thoracic cord ischemic infarct. There were no patients with normal MRI. All patients underwent transcranial Doppler (TCD). Four of 8 (50%) showed presence of microemboli with TCD; 3 of 4 (75%) had ischemic infarcts; and 1 of 4 (25%) had presence of multiple cerebral microhemorrhages on MRI. All ischemic infarcts had diffuse pattern of punctate to small lesions for ECMO survivors. The location of cerebral microhemorrhages included lobar (n = 4, 100%), deep (n = 2, 50%), and both (n = 2, 50%). Of the MRI studies, cerebrovascular related lesions were the most frequent, with punctate ischemic infarct being the most common type that may be associated with TCD microemboli. The results of the study suggest that subclinical cerebral lesions are commonly found in patients with ECMO support. Further research is needed to understand long-term effect of these cerebral lesions.

Comparison of Cerebral Embolic Events Between Right and Left Upper Extremity Access During Fenestrated/Branched Endovascular Aortic Repair

Purpose:

To evaluate the incidence and outcomes of cerebral embolic events when using right (RUE) vs left upper extremity (LUE) access for fenestrated/branched endovascular aneurysm repair (f/bEVAR).

Materials and Methods:

A retrospective review was conducted of 290 consecutive patients enrolled in a physician-sponsored Investigational Device Exemption study to evaluate f/bEVAR between 2013 and 2018. Of these, 270 patients (93%) had an upper extremity access with 12-F sheaths, including 205 patients (mean age 75±8 years; 147 men) with LUE and 65 patients (mean age 73±8 years; 42 men) with RUE access. Outcome measures were technical success, procedural metrics, major adverse events (MAEs), any stroke or transient ischemic attack (TIA), and mortality.

Results:

Technical success was higher (p=0.04) for LUE (99.6%) vs RUE access (98.4%). Patients treated via RUE access more often had extent I-III thoracoabdominal aortic aneurysms (57% vs 39%, p=0.03). Procedural metrics were similar for LUE vs RUE sides, including endovascular time (255±80 vs 246±83 minutes, respectively; p=0.23), fluoroscopy time (84±32 vs 90±35 minutes, respectively; p=0.80), and contrast volume (156±57 vs 153±56 mL, respectively; p=0.82). Total radiation exposure was significantly higher for LUE vs RUE access (2463±1912 vs 1757±1494 mGy, respectively; p=0.02). There were 2 deaths (1%) at 30 days or during hospital admission, both unrelated to access site complications. MAEs occurred in 32% of patients who had LUE and 26% of those who had RUE access (p=0.44). Five patients (2%) had embolic stroke and none had TIA. Embolic strokes were ipsilateral to the access side in 4 patients and affected the posterior circulation in 3. Two patients (1%) had hemorrhagic strokes. The incidence of stroke was 3% for LUE and 2% for RUE access (p>0.99).

Conclusion:

Fenestrated/branched stent-graft repair was associated with low rates of cerebral embolic events and no significant difference between the right vs left upper extremity approach.

Cerebrovascular events after transcatheter mitral valve interventions: a systematic review and meta-analysis

Objective

Current guidelines support the use of transcatheter mitral valve interventions to treat some selected high-risk patients with significant mitral valvulopathy. As with any other interventional cardiac procedure, concerns have been raised about cerebrovascular event. The aim of this systematic review and meta-analysis was to determine the incidence of cerebrovascular events following (1) transcatheter mitral valve edge-to-edge repair with mitral valve clip and (2) transcatheter mitral valve replacement (TMVR).

Methods

We conducted a systematic review of studies reporting the cerebrovascular adverse events after transcatheter mitral valve edge-to-edge repair and TMVR procedures. The primary endpoint was the incidence of cerebrovascular events as defined by the Mitral Valve Academic Research Consortium. An event that occurred within 30 days or during index hospitalisation was defined as periprocedural; otherwise it was defined as non-periprocedural. This study was designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Aggregated study-level data were pooled using a random effect model. The quality of each study was appraised with the Hawker checklist, a method of systematically reviewing research from different paradigms.

Results

Sixty studies totalling 28 155 patients undergoing edge-to-edge repair with mitral valve clip were included in the analysis. Periprocedural stroke and non-periprocedural stroke rates were 0.9% (95% CI 0.6 to 1.1) and 2.4% (95% CI 1.6 to 3.2), respectively. For TMVR procedures, 26 studies including 1910 patients were analysed. The estimated periprocedural stroke incidence was 1% (95% CI 0.5 to 1.8) compared with 7% (95% CI 0.8 to 18.5) for non-periprocedural stroke.

Conclusions

Transcatheter mitral valve interventions are associated with low rates of cerebrovascular events. The exact mechanisms of these complications are still poorly understood given the relative paucity of good quality data.

Trial registration number

CRD42019117257.

Association between high sensitivity C-reactive protein (hs-CRP) levels and the risk of major adverse cardiovascular events (MACE) and/or microembolic signals after carotid angioplasty and stenting

Background

To evaluate the association between pre/post-procedural high sensitive C-reactive protein (hs-CRP) level and hs-CRP difference, and the risk of major adverse cardiovascular events (MACE) or new diffusion-weighted MRI lesions after carotid angioplasty and stenting (CAS).

Methods

In this study, conducted in 2016 in Shiraz (Iran), patients who underwent diagnostic angiography and CAS were recruited. CAS was performed with distal embolic protection device on patients with both standard and high risk of endarterectomy. Pre/post-procedural hs-CRP, and hs-CRP difference were determined by immunoenzymometric assay method.

Results

A total of 50 patients with diagnostic angiography and 60 patients with CAS were enrolled. No death, myocardial infarction, ischemic or hemorrhagic stroke, and need to revascularization occurred during the 30-days of the post-procedural period. Accordingly, the statistical evaluation in associating MACE and hs-CRP levels was impossible. Angioplasty was associated with higher frequency of elevated post-procedural hs-CRP in comparison to angiography (P=0.003). The higher age, symptomatic lesions, negative history of hypertension, and hs-CRP difference had significant association with the presence of new DWI lesions in univariate analysis (all P<0.05). Angioplasty of left carotid bulb and post-procedural hs-CRP levels was very close to the level of significance (P=0.06). But only left sided lesions had positive association (P=0.037) and hypertension had negative association (P=0.037) in multivariate regression analysis. There were significant association between post-procedural hs-CRP level (P=0.02) and hs-CRP difference (P=0.003), and the number of new lesions; and the hs-CRP difference and the accumulated lesion surface area (P=0.009).

Conclusion

Post-procedural hs-CRP and hs-CRP difference may predict embolic complications of CAS.

Cognitive Function and Atrial Fibrillation: From the Strength of Relationship to the Dark Side of Prevention. Is There a Contribution from Sinus Rhythm Restoration and Maintenance?

Atrial fibrillation (AF) is the most common chronic cardiac arrhythmia with an increasing prevalence over time mainly because of population aging. It is well established that the presence of AF increases the risk of stroke, heart failure, sudden death, and cardiovascular morbidity. In the last two decades several reports have shown an association between AF and cognitive function, ranging from impairment to dementia. Ischemic stroke linked to AF is a well-known risk factor and predictor of cognitive decline. In this clinical scenario, the risk of stroke might be reduced by oral anticoagulation. However, recent data suggest that AF may be a predictor of cognitive impairment and dementia also in the absence of stroke. Cerebral hypoperfusion, reduced brain volume, microbleeds, white matter hyperintensity, neuroinflammation, and genetic factors have been considered as potential mechanisms involved in the pathogenesis of AF-related cognitive dysfunction. However, a cause-effect relationship remains still controversial. Consequently, no therapeutic strategies are available to prevent AF-related cognitive decline in stroke-free patients. This review will analyze the potential mechanisms leading to cognitive dysfunction in AF patients and examine the available data on the impact of a sinus rhythm restoration and maintenance strategy in reducing the risk of cognitive decline.

Cerebral Embolic Risk During Transcatheter Mitral Valve Interventions: An Unaddressed and Unmet Clinical Need?

As new transcatheter mitral valve (MV) interventions continuously evolve, potential procedure-related adverse events demand careful investigation. The risk of cerebral embolic damage is ubiquitous in any left-sided structural heart intervention (and potentially linked to long-term neurocognitive sequelae); therefore, efforts to evaluate these aspects in the field of catheter-based MV procedures are justified. Given the peculiarities of MV anatomy, MV disease, and MV procedures, the lessons learned from other transcatheter heart interventions (i.e., transcatheter aortic valve replacement) cannot be directly translated to MV applications. Through a systematic assessment of available evidence, the authors present and discuss procedure- and patient-related factors potentially associated with cerebral embolic risk during catheter-based MV interventions. Given the paucity of available data in this field, future large, dedicated studies are needed to understand whether cerebral embolic injury represents a real clinical issue during MV procedures.

Technical improvements in carotid revascularization based on the mechanism of procedural stroke

The benefit of carotid revascularization in patients with severe carotid artery stenosis is hampered by the risk of stroke due to the intervention itself. The risk of periprocedural strokes is higher for carotid artery stenting (CAS) as compared to carotid endarterectomy (CEA). Over the past years, the pathophysiological mechanism responsible for periprocedural stroke seems to unfold step by step. Initially, all procedural strokes were thought to be the result of technical errors during surgical repair: cerebral ischemia due to clamping time of the carotid artery, cerebral embolization of atherosclerotic debris due to manipulation of the atheroma or thrombosis of the artery. Following improvements in surgical techniques, technical skills, new intraoperative monitoring technologies such as angioscopy, and the results of the first large clinical randomized controlled trials (RCT) it was believed that most periprocedural strokes were of thromboembolic nature, while a large part of these caused by technical error. Nowadays, analyses of underlying pathophysiological mechanisms of procedural stroke make a clinically relevant distinction between intra-procedural and postprocedural strokes. Intra-procedural stroke is defined as hypoperfusion due to clamping (CEA) or dilatation (CAS) and embolization from the carotid plaque (both CEA and CAS). Postprocedural stroke can be caused by thrombo-embolisation but seems to have a primarily hemodynamic origin. Besides thrombotic occlusion of the carotid artery, cerebral hyperperfusion syndrome (CHS) due to extensively increased cerebral revascularization is the most reported pathophysiological mechanism of postprocedural stroke. Multiple technical improvements have attempted to lower the risk of periprocedural stroke. The introduction of antiplatelet therapy (APT) has significantly reduced the risk of thromboembolic events in patients with carotid stenosis. Over the years, recommendations regarding APT changed. While for a long time APT was discontinued prior to surgery because of a fear of increased bleeding risk, nowadays continuation of APT during carotid intervention (aspirin monotherapy or even dual APT including clopidogrel) is found to be safe and effective. In CAS patients, dual APT up to three months' postprocedural is considered best. Stent design and cerebral protection devices (CPD) for CAS procedure are continuously under development. Trials have suggested a benefit of closed-cell stent design over open-cell stent design in order to reduce procedural stroke, while the benefit of CPD during stenting is still a matter of debate. Although CPD reduce the risk of procedural stroke, a higher number of new ischemic brain lesions detected on diffusion weighted imaging was found in patients treated with CPD. In patients undergoing CEA under general anesthesia, adequate use of cerebral monitoring (EEG and transcranial Doppler [TCD]) has reduced the number of intraoperative stroke by detecting embolization and thereby guiding the surgeon to adjust his technique or to selectively shunt the carotid artery. In addition, TCD is able to adequately identify and exclude patients at risk for CHS. For CAS, the additional value of periprocedural cerebral monitoring to prevent strokes needs urgent attention. In conclusion, this review provides an overview of the pathophysiological mechanism of stroke following carotid revascularization (both CAS and CEA) and of the technical improvements that have contributed to reducing this stroke risk.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Early Recurrent Ischemic Lesions in Patients With Cryptogenic Stroke and Patent Foramen Ovale: An Observational Study

Background: Randomized controlled trials indicate that patent foramen ovale (PFO) closure reduces risk of stroke recurrence in patients with cryptogenic stroke and PFO. However, the optimal time point for PFO closure is unknown and depends on the risk of stroke recurrence.

Objective: We aimed to investigate risk of early new ischemic lesions on cerebral magnetic resonance imaging (MRI) in cryptogenic stroke patients with and without PFO.

Methods: Cryptogenic stroke patients underwent serial MRI examinations within 1 week after symptom onset to detect early new ischemic lesions. Diffusion-weighted imaging (DWI) lesions were delineated, co-registered, and analyzed visually for new hyperintensities by raters blinded to clinical details. A PFO was classified as stroke-related in patients with PFO and a Risk of Paradoxical Embolism (RoPE) score >5 points.

Results: Out of 80 cryptogenic stroke patients, risk of early recurrent DWI lesions was not significantly different in cryptogenic stroke patients with and without PFO. Similar results were observed in patients ≤60 years of age. Patients with a stroke-related PFO even had a significantly lower risk of early recurrent ischemic lesions compared to all other patients with cryptogenic stroke (unadjusted odds ratio 0.23 [95% confidence interval 0.06–0.87], P = 0.030).

Conclusion: Our data argue against a high risk of early stroke recurrence in patients with cryptogenic stroke and PFO.

Preconditioning in the Rhesus Macaque Induces a Proteomic Signature Following Cerebral Ischemia that Is Associated with Neuroprotection

Each year, thousands of patients are at risk of cerebral ischemic injury, due to iatrogenic responses to surgical procedures. Prophylactic treatment of these patients as standard care could minimize potential neurological complications. We have shown that protection of brain tissue, in a non-human primate model of cerebral ischemic injury, is possible through pharmacological preconditioning using the immune activator D192935. We postulate that preconditioning with D192935 results in neuroprotective reprogramming that is evident in the brain following experimentally induced cerebral ischemia. We performed quantitative proteomic analysis of cerebral spinal fluid (CSF) collected post-stroke from our previously published efficacy study to determine whether CSF protein profiles correlated with induced protection. Four groups of animals were examined: naïve animals (no treatment or stroke); animals treated with vehicle prior to stroke; D192935 treated and stroked animals, further delineated into two groups, ones that were protected (small infarcts) and those that were not protected (large infarcts). We found that distinct protein clusters defined the protected and non-protected animal groups, with a 16-member cluster of proteins induced exclusively in D192935 protected animals. Seventy percent of the proteins induced in the protected animals have functions that would enhance neuroprotection and tissue repair, including several members associated with M2 macrophages, a macrophage phenotype shown to contribute to neuroprotection and repair during ischemic injury. These studies highlight the translational importance of CSF biomarkers in defining mechanism and monitoring responses to treatment in development of stroke therapeutics.

Sonolysis in risk reduction of symptomatic and silent brain infarctions during coronary stenting (SONOREDUCE): Randomized, controlled trial

BACKGROUND

Silent brain infarcts can be detected on magnetic resonance imaging (MRI) in ~22% of patients after coronary angioplasty and stenting (CS). The effect of periprocedural sonolysis on the risk of new brain infarcts during CS was examined.

METHODS

Patients undergoing elective CS were allocated randomly to a bilateral sonolysis group (70 patients, 58 men; mean age, 59.9 years) or a control group (74 patients, 45 men; mean age, 65.5 years). Neurologic examination, cognitive function tests, and brain MRI were performed prior to intervention and at 24 h after CS. Neurologic examination and cognitive function tests were repeated at 30 days after CS.

RESULTS

No significant differences were observed in the number of patients with new infarcts (25.7 vs. 18.9%, P = 0.423), the number of lesions (1.3 ± 1.0 vs. 2.9 ± 5.3, P = 0.493), lesion volume (0.16 ± 0.34 vs. 0.28 ± 0.60 mL, P = 0.143), and the number of patients with new ischemic lesions in the insonated MCA territories (18.6vs. 17.6%, P = 0.958) between the sonolysis group and the control group. There were no cases of stroke, transient ischemic attack, myocardial infarction, or death in the two groups. Intracranial bleeding was reported only in 1 patient in the control group (0 vs. 1.4%, P = 0.888). Clock-drawing test scores at 30 days were significantly higher in the sonolysis group than in the control group (median 3.0 vs. 2.5, P = 0.031).

CONCLUSIONS

Sonolysis does not reduce the risk of new brain infarcts after CS. The effect of sonolysis on number and volume of ischemic lesions and cognitive function should be assessed in further studies.

Angioplasty and Stenting of Intracranial Arterial Stenosis in Perforator-Bearing Segments: A Comparison Between the Anterior and the Posterior Circulation

Background and Purpose: Subgroup analysis of the SAMMPRIS trial showed a higher rate of periprocedural perforator strokes with the Wingspan stent in the basilar artery in patients with symptomatic intracranial atherosclerotic stenosis (ICAS). It remains unclear whether angioplasty (PTA) alone or in combination with other stent types (PTAS) will yield similar results in perforator-bearing segments of the anterior and posterior circulation.

Methods: We retrospectively analyzed the periprocedural complication rate, long term outcome and stroke etiology in 59 consecutive patients with ICAS of the middle cerebral artery (79 treatments) and 67 patients with ICAS of the intracranial vertebral and basilar artery (76 treatments) treated with PTA or PTAS from 2007 to 2015 in a high-volume neuro-interventional center.

Results: Periprocedural symptomatic ischemic strokes occurred significantly more often in patients with posterior vs. anterior ICAS treatment (14.5 vs. 5.1%, p = 0.048). During a mean follow-up period of 19 (±23.7) months, 5 recurrent ischemic and 2 hemorrhagic strokes (10.4%) occurred in the territory of the treated artery in posterior circulation compared to 2 ischemic strokes in the anterior circulation (3.4%, p = 0.549). Overall, significantly more patients treated for a posterior ICAS suffered a periprocedural or follow-up stroke [25% vs. 11.4%, p = 0.024]. Periprocedural ischemic strokes were predominantly perforator strokes (73.3%), while all ischemic strokes during follow-up were caused by distal embolization (57.1%) or delayed stent occlusion (42.9%). There was no difference between PTA alone and PTAS.

Conclusion: The periprocedural and long-term symptomatic stroke rate was significantly higher in the treatment of perforator-bearing arteries in the posterior circulation. There was no difference between PTA alone or PTAS.

Neurological Sequelae and Clinical Outcomes After Lung Transplantation

Background

Neurological complications are common after lung transplantation. However, no large cohort studies have examined the incidence, predictors, and clinical significance of neurological events sustained by lung transplant recipients.

Methods

We conducted a retrospective cohort analysis of a consecutive series of lung transplant recipients, transplanted at Duke University Medical Center between May 2014 and February 2017 (n = 276). Early neurological complications (ie, occurring during the first week after transplant) were documented by transplant mental health specialists and included delirium, ischemic injury, and posterior reversible encephalopathy syndrome. Analyses accounted for age, native disease, sex, type of transplant, lung allocation score, and primary graft dysfunction. The objectives of the study were to characterize the prevalence and predictors of early neurological sequelae (NSE), occurring during the first week posttransplant, and the association between NSE and subsequent clinical outcomes, including length of stay and mortality.

Results

Neurological sequelae were common, occurring in 123 (45%) patients. Fifty-seven patients died over a follow-up interval of 2.1 years. The most common NSE were postoperative delirium (n = 110 [40%]) and posterior reversible encephalopathy syndrome (n = 12 [4%]), followed by stroke/transient ischemic attack and neurotoxicity. Higher lung allocation score was the strongest predictor of delirium. The presence of a NSE was associated with longer length of hospital stay (32 days vs 17 days, P < 0.001) and greater mortality (hazard ratio, 1.90; 95% confidence interval, 1.09-3.32], P = 0.024), with the greatest mortality risk occurring approximately 2 years after transplantation.

Conclusions

Neurological events are relatively common after lung transplantation and associated with adverse clinical outcomes.

Postoperative cognitive dysfunction and mortality following lung transplantation

Preliminary evidence suggests that postoperative cognitive dysfunction (POCD) is common after lung transplantation. The impact of POCD on clinical outcomes has yet to be studied. The association between POCD and longer-term survival was therefore examined in a pilot study of posttransplantation survivors. Forty-nine participants from a prior randomized clinical trial underwent a neurocognitive assessment battery pretransplantation and 6 months posttransplantation, including assessments of the domains of Executive Function (Trail Making Test, Stroop, Digit Span), Processing Speed (Ruff 2 and 7 Test, Digit Symbol Substitution Test), and Verbal Memory (Verbal Paired Associates, Logical Memory, Animal Naming, and Controlled Oral Word Association Test). During a 13-year follow-up, 33 (67%) participants died. Greater neurocognition was associated with longer survival (hazard ratio [HR] = 0.49 [0.25-0.96], P = .039), and this association was strongest on tests assessing Processing Speed (HR = 0.58 [0.36-0.95], P = .03) and Executive Function (HR = 0.52 [0.28-0.97], P = .040). In addition, unadjusted analyses suggested an association between greater Memory performance and lower risk of CLAD (HR = 0.54 [0.29-1.00], P = .050). Declines in Executive Function tended to be predictive of worse survival. These preliminary findings suggest that postoperative neurocognition is predictive of subsequent mortality among lung transplant recipients. Further research is needed to confirm these findings in a larger sample and to examine mechanisms responsible for this relationship.

Cerebral embolization, silent cerebral infarction and neurocognitive decline after thoracic endovascular aortic repair

Background

Silent cerebral infarction is brain injury detected incidentally on imaging; it can be associated with cognitive decline and future stroke. This study investigated cerebral embolization, silent cerebral infarction and neurocognitive decline following thoracic endovascular aortic repair (TEVAR).

Methods

Patients undergoing elective or emergency TEVAR at Imperial College Healthcare NHS Trust and Guy's and St Thomas' NHS Foundation Trust between January 2012 and April 2015 were recruited. Aortic atheroma graded from 1 (normal) to 5 (mobile atheroma) was evaluated by preoperative CT. Patients underwent intraoperative transcranial Doppler imaging (TCD), preoperative and postoperative cerebral MRI, and neurocognitive assessment.

Results

Fifty-two patients underwent TEVAR. Higher rates of TCD-detected embolization were observed with greater aortic atheroma (median 207 for grade 4–5 versus 100 for grade 1–3; P = 0·042), more proximal landing zones (median 450 for zone 0–1 versus 72 for zone 3–4; P = 0·001), and during stent-graft deployment and contrast injection (P = 0·001). In univariable analysis, left subclavian artery bypass (β coefficient 0·423, s.e. 132·62, P = 0·005), proximal landing zone 0–1 (β coefficient 0·504, s.e. 170·57, P = 0·001) and arch hybrid procedure (β coefficient 0·514, s.e. 182·96, P &lt; 0·001) were predictors of cerebral emboli. Cerebral infarction was detected in 25 of 31 patients (81 per cent) who underwent MRI: 21 (68 per cent) silent and four (13 per cent) clinical strokes. Neurocognitive decline was seen in six of seven domains assessed in 15 patients with silent cerebral infarction, with age a significant predictor of decline.

Conclusion

This study demonstrates a high rate of cerebral embolization and neurocognitive decline affecting patients following TEVAR. Brain injury after TEVAR is more common than previously recognized, with cerebral infarction in more than 80 per cent of patients.

Stent-assisted treatment of ruptured intracranial aneurysms in the acute phase: A single center experience

Introduction

The purpose of this study was to analyze the results of patients with ruptured aneurysms who were treated with a specific microstent in the acute phase of subarachnoid hemorrhage.

Methods

Data from patients with acutely-ruptured intracranial aneurysm treated with the Neuroform stent in the period between 2003 and 2016 were retrospectively assessed, addressing aneurysm occlusion and clinical outcome with a focus on periprocedural complications.

Results

Twenty-nine consecutive patients with ruptured intracranial aneurysms were included in the analysis. Periprocedural hemorrhagic complications were stated in six patients, leading to death in four. Thromboembolic complications were observed in seven patients, among whom only one affected the clinical outcome with death due to basilar thrombosis. Immediate complete occlusion and occlusion with residual neck was achieved in 79.3% of cases.

Conclusion

Stent-assisted coiling of acutely-ruptured aneurysms achieves good immediate aneurysm occlusion. Rates of intra- and periprocedural adverse events observed in this series were significant, but did not translate to corresponding morbidity and mortality in all cases. The retrospective analysis did not allow assessing the overall risks of endovascular therapy with stent use in ruptured and complex aneurysm when compared to the overall risks with other alternative options.

•

SAC of acutely ruptured aneurysms achieves good immediate aneurysm occlusion.

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Adverse events were frequent, but did not translate to morbidity and mortality in all cases.

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SAC was only applied when alternative strategies would not be considered safe and sufficient.

Radiographic and symptomatic brain ischemia in CEA and CAS: A systematic review and meta-analysis

OBJECTIVE

In a systematic review, we compared ratio of new periprocedural radiographic brain ischemia (RBI) to the number of strokes and TIAs among patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

We searched 5 databases for entries related to brain ischemia in CEA or CAS from inception through September 2015. We included articles with CEA or CAS and systematic performance of preprocedural and postprocedural brain MRI and reporting of RBI and stroke incidence. We calculated a symptomatic risk ratio of number of strokes and TIAs to RBI. Random effects models were used.

RESULTS

Fifty-nine studies (5,431 participants) met the inclusion criteria. There were 22 cohorts in CEA, 34 in CAS with distal protection, 8 in CAS with proximal protection, 9 in CAS without protection, and 9 in CAS with unspecified devices. Overall, 30.7% (95% confidence interval [CI] 26.6%-34.7%) had RBI, while 3.2% (95% CI 2.6%-3.8%) had clinical strokes or TIAs, with a stroke and TIA to RBI weighted ratio of 0.18 (95% CI 0.15-0.22). CEA had lower incidence of RBI compared to CAS (13.0% vs 37.4%) and also lower number of strokes and TIAs (1.8% vs 4.1%). The stroke and TIA to RBI ratio did not differ across 5 different types of carotid interventions (p = 0.58).

CONCLUSIONS

One in 5 persons with periprocedural radiographic brain ischemia during CEA and CAS had strokes and TIAs. The stable ratio of stroke and TIA to radiographic ischemia suggests that MRI ischemia could serve as a surrogate measure of periprocedural risk.

Vascular territorial segmentation and volumetric blood flow measurement using dynamic contrast enhanced magnetic resonance angiography of the brain

This study proposes a method for territorial segmentation and volumetric flow rate (VFR) distribution measurement of cerebral territories based on time-resolved contrast enhanced magnetic-resonance-angiography (MRA). The method uses an iterative region-growing algorithm based on bolus-arrival-time with increased temporal resolution. Eight territories were segmented: (1) right and (2) left internal carotid arteries, including the middle cerebral artery (ICA+MCA), excluding the anterior cerebral arteries (ACA); (3) right and left ACA (R+L-ACA); (4) right and (5) left external carotid arteries (ECA); (6) right and (7) left posterior cerebral arteries (PCA); and (8) vertebrobasilar territory. VFR percentage, relative to the entire brain (rVFR), was measured based on territorial volume as a function of time. Mean rVFR values of fifteen healthy subjects were: ICA+MCA = 23 ± 2%, R + L-ACA = 17 ± 3%, ECA = 4 ± 2%, PCA = 12 ± 2%, and vertebrobasilar territory = 31 ± 4%. Excluding the ECA-rVFR, which is underestimated, these values are comparable to previously reported values. Six subjects were scanned twice, demonstrating comparable and even higher reproducibility than previously reported using phase-contrast, yet with faster scan time (∼1 min). This method was implemented in one patient with MCA occlusion and one with Moyamoya syndrome scanned before and after bypass surgery, demonstrating its clinical potential for quantitative assessment of the degree of occlusion and the effect of surgery.

Emboli and cognitive state in surgical vs. transcatheter aortic valve replacement

Background Neurologic complications and neurocognitive impairment due to cerebral emboli are common following heart surgery. This study aimed to compare the number of emboli detected in the middle cerebral artery in open aortic valve replacement, apical and femoral transcatheter aortic valve replacement, and also to test for an association between the number of emboli captured in each procedure and changes in the patient's cognitive state. Methods Forty-four patients were enrolled in the study, 36 of whom were included in the final analyses: 14 underwent open aortic valve replacement, 2 had femoral transcatheter aortic valve replacement, and 10 had apical transcatheter aortic valve replacement. The number of emboli was detected by middle cerebral artery intraoperative transcranial Doppler ultrasound. The day before the elective surgery and 6-12 weeks later, all patients underwent neurocognitive evaluations by the Mini-Mental State Examination; the difference was tested for an association with the number of emboli. Results Open aortic valve replacement resulted in a significantly greater number of emboli (8555, range 2999-12489) than apical (1962, range 521-3850) or femoral (1220, range 948-1946) transcatheter approaches ( p = 0.003). Both transcatheter approaches yielded a comparable amount of emboli ( p = 0.798). No significant association was observed between the change in Mini-Mental State Examination score and the mean number of emboli ( r = 0.026; p = 0.907). Conclusions Compared to transcatheter aortic valve replacement, more cerebral emboli are detected during surgical aortic valve replacement; however, this does not appear to adversely affect a patient's cognitive state.

Preclinical Development of a Prophylactic Neuroprotective Therapy for the Preventive Treatment of Anticipated Ischemia-Reperfusion Injury

Ischemia-reperfusion brain injury can be iatrogenically induced secondary to life-saving procedures. Prophylactic treatment of these patients offers a promising prevention for lifelong complications. We postulate that a cytosine-guanine (CpG) oligodeoxynucleotide (ODN) can provide robust antecedent protection against cerebral ischemic injury with minimal release of pro-inflammatory cytokines, making it an ideal candidate for further clinical development. Mouse and nonhuman primate (NHP) models of cerebral ischemic injury were used to test whether an A-type CpG ODN, which induces minimal systemic inflammatory cytokine responses, can provide prophylactic protection. Extent of injury in the mouse was measured by histological staining of live tissue. In the NHP, injury was assessed 2 and 7 days post-occlusion from T2-weighted magnetic resonance images and neurological and motor deficits were cataloged daily. Plasma cytokine levels were measured using species-specific Luminex assays. Prophylactic administration of an A-type CpG ODN provided robust protection against cerebral ischemic injury in the mouse with minimal systemic inflammation. Rhesus macaques treated with D192935, a mixture of human optimized A-type CpG ODNs, had smaller infarcts and demonstrated significantly less neurological and motor deficits following ischemic injury. Our findings demonstrate the translational potential of D192935 as a prophylactic treatment for patients at risk of cerebral ischemic injury.