Clinical Importance of the Posterior Inferior Cerebellar Artery: A Review of the Literature.

The posterior inferior cerebellar artery (PICA), with its unique anatomical complexity, is of great clinical importance and involved in many diseases including aneurysm, ischemic stroke, neurovascular compression syndrome (NVCS), arteriovenous malformation (AVM), and brain tumor. However, a comprehensive systematic review of the importance of the PICA is currently lacking. In this study, we perform a literature review of PICA by searching all the associated papers in the PUBMED database hoping to provide a better understanding of the artery. The PICA has tortuous and variable course and territory, divided into 5 segments. Various aneurysms involving PICA were not uncommon, of which the treatment is challenging. The PICA infarct typically manifests lateral medullary syndrome (LMS) and is more likely to cause mass effects. The PICA frequently compresses the medulla and the cranial nerves resulting in various neurovascular compression syndromes (NVCS). Arteriovenous malformation (AVM) fed by PICA are associated with aneurysm and dissection which have high risk of rupture and worse outcome. PICA injured by head trauma can cause fatal SAH. VA terminating in PICA probably cause Bow hunter's syndrome (BHS). The PICA supplies many brain tumors and can be used in intracerebellar chemotherapy. The PICA can be exposed and injured during surgeries especially in telovelar approach, and it also plays an important role in bypass surgeries, hinting the surgical importance of PICA. In conclusion, PICA is very important in clinical practice.

[Stenting of subtotal conclusion of internal carotid artery and comparing the cerebral embolic load of proximal balloon protection device with distal filter protection device].

OBJECTIVE: To study the safety, efficacy and perioperative complications of endovascular therapy in the treatment of subtotal conclusion of internal carotid artery(ICA) in patients. To compare the cerebral embolic load of proximal balloon protection device versus distal filter protection device during the operation. METHODS: Review all the operations of stenting for subtotal conclusion of ICA in Xuanwu hospital. New cerebral infarction after stenting was assessed by diffusion-weighted magnetic resonance imaging. Count the number of new ischemic lesions of every patient. RESULTS: 35 patients with subtotal conclusion of ICA received endovascular stenting. Proximal protective device was used for 21 patients. Distal protective device was used for 14 patients. All procedures succeeded. 32 patients received the cerebral MRI 1 week before and within 48 hours after the operation. Compared with filter protection(n = 14), proximal balloon device(n = 18) resulted in a significant reduction in the incidence of new cerebral infarction (6/18 vs 10/14, P = 0.03). The number of new cerebral ischemic lesions were significant reduced by proximal balloon device (1/18 vs 4/14, P = 0.0006) . There were no serious cardiovascular events in 35 patients during the operation and the following up 3 months. 3 patients had restenosis which was demonstrated by ultrasound of ICA at 3 months after stenting. CONCLUSIONS: Endovascular stenting may be a safe and valid method for the treatment of subtotal occlusion of ICA. For the stenting of subtotal occlusion of ICA, proximal balloon protection device as compared with filter protection may reduce the embolic load to the brain more effectively. The stenting of subtotal occlusion of ICA still needs the randomized trails to confirm the safety and validity.

Endovascular Thrombectomy Versus Bridging Thrombolysis: Real-World Efficacy and Safety Analysis Based on a Nationwide Registry Study.

Background It was uncertain if direct endovascular thrombectomy (ET) was superior to bridging thrombolysis (BT) for patients with acute ischemic stroke caused by large-vessel occlusions. We aimed to examine real-world clinical outcomes of ET using nationwide registry data in China and to compare the efficacy and safety between BT and direct ET. Methods and Results Patients treated with ET from a nationwide registry study in China were included. Rapid neurological improvement, intracranial hemorrhage, and in-hospital mortality were compared between the 2 groups using multivariate logistic models and propensity-score matching analyses. A total of 7674 patients from 592 stroke centers were included. The median onset-to-puncture time, onset-to-door time, and door to puncture time were 290, 170, and 99 minutes, respectively. A total of 2069 (27.0%) patients received BT treatment. Patients in the BT group had a significantly shorter onset-to-puncture time (235 versus 323 minutes; P<0.001) and onset-to-door time (90 versus 222 minutes; P<0.001) compared with the direct ET group. The prior use of intravenous thrombolysis was associated with a higher rate of rapid neurological improvement (adjusted odds ratio [OR], 0.83; 95% CI, 0.71-0.96) and higher risk of intracranial hemorrhage (adjusted OR, 1.46; 95% CI, 1.18-1.80) in multivariate analyses and propensity-score matching analyses. Conclusions This study reflects the current application of ET in China. More patients received direct ET than BT. Our results suggested that favorable short-term outcomes could be achieved with BT compared with direct ET. Higher risk of intracranial hemorrhage was observed in the BT group.

Processed Multiparameter Electroencephalogram-Guided General Anesthesia Management Can Reduce Postoperative Delirium Following Carotid Endarterectomy: A Randomized Clinical Trial.

Background: Patients undergoing carotid endarterectomy (CEA) for severe carotid stenosis are vulnerable to postoperative delirium, a complication frequently associated with poor outcome. This study investigated the impact of processed electroencephalogram (EEG)-guided anesthesia management on the incidence of postoperative delirium in patients undergoing CEA. Methods: This single-center, prospective, randomized clinical trial on 255 patients receiving CEA under general anesthesia compared the outcomes of patient state index (PSI) monitoring [SEDLine Brain Function Monitor (Masimo, Inc, Irvine, CA)] (standard group, n = 128) with PSI combined with density spectral array(DSA) -guided monitoring (intervention group, n = 127) to reduce the risk of intraoperative EEG burst suppression. All patients were monitored by continuous transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to avoid perioperative cerebral hypoperfusion or hyperperfusion. According to the surgical process, EEG suppression time was calculated separately for three stages: S1 (from anesthesia induction to carotid artery clamping), S2 (from clamping to declamping), and S3 (from declamping to the end of surgery). The primary outcome was incidence of postoperative delirium according to the Confusion Assessment Method algorithm during the first 3 days post-surgery, and secondary outcomes were other neurologic complications and length of hospital stay. Results: There were no episodes of cerebral hypoperfusion or hyperperfusion according to TCD and NIRS monitoring in either group during surgery. The incidence of postoperative delirium within 3 days post-surgery was significantly lower in the intervention group than the standard group (7.87 vs. 28.91%, P < 0.01). In the intervention group, the total EEG suppression time and the EEG suppression time during S2 and S3 were shorter (Total, 0 "0" vs. 0 "1.17" min, P = 0.04; S2, 0 "0" vs. 0 "0.1" min, P < 0.01; S3, 0 "0" vs. 0 "0" min, P = 0.02). There were no group differences in incidence of neurologic complications and length of postoperative hospital stay. Conclusion: Processed electroencephalogram-guided general anesthesia management, consisting of PSI combined with DSA monitoring, can significantly reduce the risk of postoperative delirium in patients undergoing CEA. Patients, especially those exhibiting hemodynamic fluctuations or receiving surgical procedures that disrupt cerebral perfusion, may benefit from the monitoring of multiple EEG parameters during surgery. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03622515.

Impact of metabolic syndrome on short-term outcome of carotid revascularization: a large sample size study in Chinese population.

BACKGROUND: Metabolic syndrome (MetS) is relatively common worldwide and an important risk factor for cardiovascular diseases. It is closely linked to arterial stiffness of the carotid artery. However, the association of MetS with the safety of carotid revascularization has been rarely studied. The aim of this study was to observe the current status of MetS and its components in Chinese carotid revascularized patients, and investigate the impact on major adverse clinical events (MACEs) after carotid endarterectomy (CEA) or carotid artery stenting (CAS). METHODS: From January 2013 to December 2017, patients undergoing CEA or CAS in the Neurosurgery Department of Xuanwu Hospital were retrospectively recruited. The changes in prevalence of MetS and each component with time were investigated. The primary outcome was 30-day post-operative MACEs. Univariable and multivariable analyses were performed to identify the impact of MetS on CEA or CAS. RESULTS: A total of 2068 patients who underwent CEA (766 cases) or CAS (1302 cases) were included. The rate of MetS was 17.9%; the prevalence rate of MetS increased with time. The occurrence rate of MACEs in CEA was 3.4% (26 cases) and in CAS, 3.1% (40 cases). There was no statistical difference between the two groups (3.4% vs. 3.1%, P = 0.600). For CEA patients, univariate analysis showed that the MACE (+) group had increased diabetes history (53.8% vs. 30.9%, P = 0.014) and MetS (34.6% vs. 15.8%, P = 0.023). For CAS patients, univariate analysis showed that the MACE (+) group had increased coronary artery disease history (40.0% vs. 21.6%, P = 0.006) and internal carotid artery tortuosity (67.5%% vs. 37.6%, P < 0.001). Furthermore, the MACE (+) group had higher systolic blood pressure (143.38 ±â€Š22.74 vs. 135.42 ±â€Š17.17 mmHg, P = 0.004). Multivariable analysis showed that the influencing factors for MACEs in CEA included history of diabetes (odds ratio [OR] = 2.345; 95% confidence interval [CI] = 1.057-5.205; P = 0.036) and MetS (OR = 2.476; 95% CI = 1.065-5.757; P = 0.035). The influencing factors for MACEs in CAS included systolic blood pressure (OR = 1.023; 95% CI = 1.005-1.040; P = 0.010), coronary artery disease (OR = 2.382; 95% CI = 1.237-4.587; P = 0.009) and internal carotid artery tortuosity (OR = 3.221; 95% CI = 1.637-6.337; P = 0.001). CONCLUSIONS: The prevalence rate of MetS increased with time in carotid revascularized patients. MetS is a risk for short-term MACEs after CEA, but not CAS.

Treatment of symptomatic complex posterior circulation cerebral artery stenosis with balloon-mounted stents: technique feasibility and outcome.

PURPOSE: This study aimed to retrospectively analyze a series of patients with complex posterior circulation stenosis who underwent stent-assisted angioplasty to evaluate the feasibility of the procedure and summarize the experience with regard to complications. METHODS: A total of 16 consecutive patients with 27 complex posterior circulation artery stenoses refractory to medical therapy were enrolled. Technical success rate, periprocedural complication, and long-term follow-up result were evaluated. RESULTS: The study population included 16 patients with 27 lesions. A total of 36 stents were successfully implanted. The technical success rate was 100%, and the overall periprocedural complication rate was 12.5% (2/16). During a median of 25.5 months of follow-up, three patients presented recurrent transient ischemic attacks, which were confirmed had restenosis more than 50% by control angiography or transcranial Doppler. CONCLUSIONS: Stent-assisted angioplasty is a feasible treatment method for complex posterior circulation artery stenosis. However, it appears to be associated with a relatively high periprocedural complication rate. Therefore, strict periprocedural management to reduce mortality and morbidity is needed.

Correlation between carotid intraplaque hemorrhage and clinical symptoms: systematic review of observational studies.

BACKGROUND AND PURPOSE: We sought to investigate the association between carotid intraplaque hemorrhage (IPH) and ipsilateral symptoms of cerebral ischemia. METHODS: A search was performed for clinical observational studies comparing the incidence of IPH between symptomatic and asymptomatic patients. Odds ratios (ORs) for IPH as a factor in the pathogenesis of neurologic events were calculated and combined by a meta-analysis. Interstudy heterogeneity, estimated effects, and methodologic quality of the studies were assessed. RESULTS: Thirty-one studies were included for analysis. The reported ORs varied widely. Overall, the incidence of IPH in the symptomatic groups was significantly higher than in the asymptomatic group. However, there was an apparent trend for heterogeneity (P<0.00001) between studies. The random-effects summary estimator of ORs was 2.25 (95% CI, 1.57 to 3.22; P<0.00001). To identify potential sources of heterogeneity, subgroup analyses were performed. The pooled ORs varied greatly by stratification. Major heterogeneity was found among studies with low quality, microscopic methods of examination, significant effects, small sizes, early publication, and unequal severity of carotid stenosis in both groups. Large, recent, macroscopic, or high-quality studies, as well as studies with equal degrees of stenosis, tended to yield insignificant associations. The methods in defining and evaluating hemorrhage were very heterogeneous. Characterizations of the age, size, number, and location of hemorrhages were poorly reported and highly variable. In addition, a lack of control of confounders and selection bias were frequently identified among studies. CONCLUSIONS: Statistical inferences have suggested a plausible role in the production of cerebral ischemia; however, reliable interpretation was strongly undermined by poor methodologic quality, substantial heterogeneity, and suspicious publication bias. To preciously estimate the underlying correlation, a well-designed study with uniformity in definition and evaluation for IPH might be warranted.

The correlation of carotid plaque pathohistologic features and neurological symptoms: a meta-analysis of observational studies.

OBJECTIVE: To investigate the association between the pathological features of carotid plaque and ipsilateral symptoms of cerebral ischemia. MATERIALS AND METHODS: We sought to identify clinical observational studies comparing the incidence of pathological features between symptomatic and asymptomatic carotid plaques in terms of ulceration, thrombosis and intraplaque hemorrhage (IPH), published between 1996 and 2006. A search on, PubMed was supplemented by a review of bibliographies of relevant articles and lists of references in it. Odds ratios (OR) for the presence of each feature as a role in the pathogenesis of neurological events were calculated and combined by a meta-analysis. RESULTS: We integrated 16 clinical studies totaling 2839 plaques harvested at endarterectomy procedures. The reported incidence for each feature was highly variable. The methods in defining ulceration, thrombosis and IPH were very heterogeneous. The time intervals between the latest onset of ischemic symptoms and pathological examinations varied greatly. Overall, the incidence of ulcerated plaques in the symptomatic group were significantly higher than that in the asymptomatic group (study number, n=10; OR, 2.32; 95% CI, 1.90-2.83. A random-effect model was performed among studies regarding surface thrombosis because an apparent trend for heterogeneity was observed (n=6; OR, 1.57; 95% CI, 0.68-3.64). There was no difference with respect to IPH between the two groups (n=11; OR, 1.09; 95% CI, 0.91-1.32). CONCLUSIONS: Ulcerated carotid plaque is significantly correlated with the production of neurological events, whereas thrombosis fails to correlate with ischemic symptoms because of the presence of substantial heterogeneity. The association between IPH and clinical presentations is less clear.

Central retinal artery pressure and carotid artery stenosis.

The central retinal artery (CRA), which can be non-invasively examined with ophthalmoscopy, may be regarded as an extracranial part of the cerebrovascular system. Assessment of CRA pressure may be of help in assessing the impediment of the intracranial blood circulation in patients with a carotid artery stenosis (CAS). The aim of this study was to explore the potential associations between diastolic central retinal artery pressure (diastCRAP) and CAS. The prospective longitudinal clinical observational study included patients with CAS and a control group without CAS. diastCRAP was assessed using ophthalmodynamometry. The study group consisted of 95 patients with CAS (50 of whom had >75%CAS and underwent surgery; the surgical study group) and a control group of 64 individuals without CAS. In all study participants, a lower diastCRAP was significantly associated with a higher degree of CAS (P<0.001). Multivariate analysis indicated that a higher CAS degree was significantly (correlation coefficient: r=0.75) associated with a higher brachial diastolic blood pressure (P<0.001) and lower diastCRAP (P<0.001). Within the surgical study group at the baseline of the study, diastCRAP was significantly lower at the surgical side than at the contralateral side (P=0.02). The diastCRAP on the surgical side increased significantly (P<0.001) after surgery. In the surgical study group at baseline, diastCRAP on the surgical side was not significantly associated with brachial diastolic blood pressure (P=0.22), whereas after surgery, diastCRAP was significantly associated with brachial diastolic blood pressure (P=0.001). DiastCRAP was found to be significantly and linearly correlated with the degree of CAS in intra-individual inter-eye, inter-individual and intra-individual follow-up comparisons. The strong and linear association between diastCRAP and the degree of CAS suggest that diastCRAP should be explored further for use as an indicator of cerebrovascular status.

Branch retinal artery occlusion following carotid stenting: A case report.

A 70 year old male was diagnosed with carotid stenosis and underwent carotid artery stenting (CAS). Severe postoperative complications arose subsequent to the procedure, including decreased visual acuity and symptoms of a visual field defect, and the patient was eventually diagnosed with retinal artery embolism. CAS reduces carotid plaque; however, the subsequent shedding of carotid plaque may cause retinal artery embolism, resulting in the serious loss of visual function in patients. This complication is of paramount importance and requires great consideration from the neurologist and the patients undergoing CAS. Ophthalmic evaluation is paramount following CAS due to the possibility of embolic occlusion of the retinal artery. It is imperative that patients be informed of the risk of permanent vision loss as a result of CAS.

[Evaluation by perfusion-weighted magnetic resonance to hemodynamic character and surgical effect of carotid system stenoses or occlusion].

OBJECTIVE: To evaluate hemodynamic character and surgical effect of stenoses or occlusion of carotid artery system by perfusion-weighted MRI. METHODS: Twenty-one patients with stenoses or occlusion of carotid artery system underwent surgical treatment. Two patients underwent endarterectomy, extracranial-intracranial arterial bypass to 10 patients, and percutaneous stent angioplasty to 9 patients. RESULTS: Preoperative perfusion-weighted magnetic resonance (MR) revealed normal regional cerebral blood flow in all patients, with delayed time to peak in both middle cerebral artery distribution and border zone. Postoperative perfusion-weighted MR revealed normal time to peak in border zone, but abnormal in middle cerebral artery distribution. Evaluated by perfusion-weighted MR, it showed that surgical method can improve the hemodynamic disorder of this kind of disease. The early curative effect of endarterectomy and percutaneous stent angioplasty is better than extracranial-intracranial arterial bypass. CONCLUSIONS: Perfusion-weighted MR is a good method to evaluate hemodynamic character of stenoses or occlusion of carotid artery system. Surgical method is helpful to this kind of disease, and its curative effect can be evaluated impersonally and accurately by this new technique.

Retinal embolization after carotid endarterectomy and stenting for carotid artery stenosis.

To compare the incidence of retinal arterial embolism after carotid endarterectomy (CEA) or carotid artery stenting (CAS) as a treatment for carotid artery stenosis and to determine the risk factors for retinal artery embolization, this study included all consecutive severe carotid artery stenosis patients (70-99%), diagnosed by digital subtraction angiography, who underwent CEA or CAS between February 2014 and July 2014. The study included 61 patients in the CEA group and 71 patients in the CAS group. None of the patients developed a stroke or myocardial infarction or died within 7 days of the surgery. A total of 15 patients exhibited retinal embolization including three patients who underwent CEA. None of these emboli caused symptoms. After undergoing CAS, 12 patients exhibited retinal embolization and one of the 12 patients suffered a decrease in visual acuity and visual field after CAS. The retinal embolization rate was 4.9% in the CEA group which was lower than the 16.9% rate in the CAS group (p=0.031). In addition, the retinal embolization rate in the ulcerated plaque group was higher than that in the non-ulcerated plaque group (p=0.007). Ulcerated plaques (odds ratio [OR] 5.043; 95% confidence interval [CI] 1.476-17.225; p=0.010) and CAS (OR 4.248; 95% CI 1.104-16.343; p=0.035) were independent predictors of retinal embolization. Although retinal embolization during CEA and CAS is common at our center, symptomatic embolization is not. The presence of ulcerated plaques and CAS were independent predictors of retinal embolization.

Thirty-day outcome of carotid artery stenting in Chinese patients: a single-center experience.

BACKGROUND: Carotid artery stenting (CAS) as a competing treatment modality has had to adhere to limits to gain widespread acceptance in some studies. This study analyzed the clinical data of 1700 consecutive patients after CAS to retrospectively evaluate the 30-day outcome of CAS for internal carotid artery stenosis in a Chinese population. METHODS: Medical records of 1700 patients who underwent CAS at Xuanwu Hospital affiliated to Capital Medical University between January 2001 and August 2012 were reviewed. Postoperative 30-day complication rates were analyzed and compared with those of other studies. Univariate and multivariate Logistic regression analyses were used to identify factors associated with perioperation myocardial infarction (MI), stroke, and death. RESULTS: The overall 30-day rate of MI, stroke, and death after CAS was 2.53%. In univariate analysis, patients who were symptomatic, had a neurological deficit (modified Rankin score (mRS) ≥3; P = 0.001), and who were not taking statins experienced a significantly increased rate of MI, stroke, and death (P = 0.017). In multivariate Logistic regression analysis, the presence of symptoms (odds ratio (OR) = 2.485; 95% confidence interval (CI) = 1.267-4.876; P = 0.008) and a neurological deficit (mRS ≥3) (OR = 3.025; 95% CI = 1.353-6.763; P = 0.007) were independent risk factors for perioperative MI, stroke, and death. CONCLUSIONS: According to this single-center experience, CAS may effectively prevent and treat carotid artery stenosis that would otherwise lead to stroke. Being symptomatic and having a neurological deficit (mRS ≥3) increased the risk of perioperative MI, stroke, and death.