Evaluation of microembolic signals on carotid ultrasound during pulmonary vein isolation with high-power short-duration and cryoballoon ablations: When and where do bubble and solid emboli arise?

INTRODUCTION: The underlying risks of asymptomatic embolization during high-power short-duration (HPSD) ablation for atrial fibrillation remain unclear. We aimed to evaluate microembolic signals (MESs) during HPSD ablation with power settings of 50 and 90 W in comparison with those during cryoballoon (CB) ablation using a novel carotid ultrasound-Doppler system that classifies solid and air bubble signals using real-time monitoring. METHODS AND RESULTS: Forty-seven patients underwent HPSD ablation using radiofrequency (RF), and 13 underwent CB ablation. MESs were evaluated using a novel pastable soft ultrasound probe equipped with a carotid ultrasound during pulmonary vein isolation. We compared the detailed MESs and their timing between RF and CB ablations. The number of MESs and solid signals were significantly higher in the RF group than in CB group (209 ± 229 vs. 79 ± 32, p = .047, and 83 ± 89 vs. 28 ± 17, p = .032, respectively). In RF ablation, the number of MESs, solid, and bubble signals per ablation point, or per second, was significantly higher at 90 W than at 50 W ablation. The MESs, solid, and bubble signals were detected more frequently in the bottom and anterior walls of the left pulmonary vein (LPV) ablation. In contrast, many MESs were observed before the first CB application and decreased chronologically as the procedure progressed. Signals were more prevalent during the CB interval rather than during the freezing time. Among the 28 patients, 4 exhibited a high-intensity area on postbrain magnetic resonance imaging (MRI). The MRI-positive group showed a trend of larger signal sizes than did the MRI-negative group. CONCLUSION: The number of MESs was higher in the HPSD RF group than in the CB group, with this risk being more pronounced in the 90 W ablation group. The primary detection site was the anterior wall of the LPV in RF and the first interval in CB ablation.

Ulceration location is associated with clinical course in carotid stenosis.

OBJECTIVE: Plaque ulceration in carotid artery stenosis is a risk factor for cerebral ischemic events; however, the characteristics that determine plaque vulnerability are not fully understood. We thus assessed the association between plaque ulceration sites and cerebrovascular ischemic attack. METHODS: We retrospectively collected the clinical data of 72 consecutive patients diagnosed with carotid artery stenosis with plaque ulcers. After excluding patients with pseudo-occlusion, a history of previous carotid endarterectomy or carotid artery stenting before the ulcer was first discovered, follow-up data of less than 1 month, or carotid endarterectomy or carotid artery stenting performed within 1 month after the ulcer was first discovered, 60 patients were ultimately included. Patients were divided into proximal and distal groups based on the ulcer location relative to the most stenotic point. The primary endpoints were ipsilateral cerebrovascular ischemic events ("ischemic events"), such as amaurosis fugax, transient ischemic attack, or ischemic stroke due to carotid artery stenosis with plaque ulceration. The association between ulcer location and ischemic events was also assessed. RESULTS: In the patients with plaque ulcer, more patients had proximal than distal plaque ulcers (39 vs 21; P = .028). The median follow-up duration was 3.8 years (interquartile range, 1.5-6.2 years). Nineteen patients (32%) experienced ischemic event. Ischemic events occurred more frequently in the distal than in the proximal group (18% vs 59%; P = .005). Kaplan-Meier curves demonstrated a significantly shorter event-free time in the distal group (log-rank P = .021). In univariate analysis, distal ulcer location was associated with ischemic events (odds ratio [OR], 2.94; 95% confidence interval [CI], 1.13-7.65; P = .03). Multivariate analysis using two different models also showed that distal ulcer location was independently associated with ischemic events (Model 1: OR, 3.85; 95% CI, 1.26-11.78; P = .03; Model 2: OR, 4.31; 95% CI, 1.49-12.49; P = .009). CONCLUSIONS: Patients with carotid artery stenosis and plaque ulcers located distal to the most stenotic point are more likely to experience cerebrovascular ischemic attacks. Therefore, carotid plaques with ulcers located distal to the most stenotic point may be a potential indication for surgical treatment.

Comparison of the treatment strategies for symptomatic chronic internal carotid artery occlusion.

OBJECTIVE: The best management of symptomatic chronic internal carotid artery occlusion (CICAO) has been controversial. This systematic review and meta-analysis were to compare the outcomes of different treatment strategies for symptomatic CICAO. METHODS: Two independent researchers conducted a search of articles on the treatment of CICAO published between January 2000 and October 2023 in PubMed, Web of Science, Embase, and The Cochrane Library. Twenty-two articles were eligible for meta-analysis using a random effects model to combine and analyze the data for the pooled rates of stroke and death, and the rates of procedural success and significant restenosis/occlusion. RESULTS: A total of 1193 patients from 22 publications were included in this study. Six of them had bilateral internal carotid artery occlusion. The 30-day stroke and death rates were 1.1% (95% confidence interval [CI], 0%-4.4%) in the best medical treatment (BMT) group, 4.1% (95% CI, 0.7%-9.3%; I2 = 71.4%) in the extracranial-intracranial (EC-IC) bypass group, 4.4% (95% CI, 2.4%-6.8%; I2 = 0%) in the carotid artery stenting (CAS) group, and 1.2% (95% CI, 0%-3.4%; I2 = 0%) in the combined carotid endarterectomy (CEA) and stenting (CEA + CAS) group. During follow-up of 16.5 (±16.3) months, the stroke and death rates were 19.5%, 1.2%, 6.6%, and 2.4% in the BMT, EC-IC, CAS, and CEA + CAS groups respectively. The surgical success rate was 99.7% (95% CI, 98.5%-100%; I2 = 0%) in the EC-IC group, 70.1% (95% CI, 62.3%-77.5%; I2 = 64%) in the CAS group, and 86.4% (95% CI, 78.8%-92.7%; I2 = 60%) in the CEA + CAS group. The rate of post-procedural significant restenosis or occlusion was 3.6% in the EC-IC group, 18.7% in the CAS group, and 5.7% in the CEA + CSA group. The surgical success rate was negatively associated by the length of internal carotid artery (ICA) occlusion. Surgical success rate was significantly higher in the patients with occlusive lesion within C1 to C4 segments, compared with those with occlusion distal to C4 segment (odds ratio, 11.3; 95% CI, 5.0-25.53; P < .001). A proximal stump of ICA is a favorable sign for CAS. The success rate of CAS was significantly higher in the patients with an ICA stump than that in the patients without (odds ratio, 11.36; 95% CI, 4.84-26.64; P < .01). However, the success rate of CEA + CAS was not affected by the proximal ICA stump. CONCLUSIONS: For the management of symptomatic CICAO, BMT alone is associated with the highest risk of mid- and long-term stroke and death. EC-IC bypass surgery and CEA + CAS should be considered as the choice of treatment based on operator's expertise and patient's anatomy. CAS may be employed as an alternative option in high surgical risk patients, especially when proximal ICA stump exists.

The independent and combined effects of aerobic exercise intensity and dose differentially increase post-exercise cerebral shear stress and blood flow.

This research examined the impact of aerobic exercise intensity and dose on acute post-exercise cerebral shear stress and blood flow. Fourteen young adults (27 ± 5 years of age, eight females) completed a maximal oxygen uptake ( V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ ) treadmill test followed by three randomized study visits: treadmill exercise at 30% of V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ for 30 min, 70% of V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ for 30 min and 70% of V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ for a duration that resulted in caloric expenditure equal to that in the 30% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ visit (EqEE). A venous blood draw and internal carotid artery (ICA) ultrasound were collected before and immediately following exercise. ICA diameter and blood velocity were determined using automated edge detection software, and blood flow was calculated. Using measures of blood viscosity, shear stress was calculated. Aerobic exercise increased ICA shear stress (time: P = 0.005, condition: P = 0.012) and the increase was greater following exercise at 70% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ (∆4.1 ± 3.5 dyn/cm2) compared with 30% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ (∆1.1 ± 1.9 dyn/cm2; P = 0.041). ICA blood flow remained elevated following exercise (time: P = 0.002, condition: P = 0.010) with greater increases after 70% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ (Δ268 ± 150 mL/min) compared with 30% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ (∆125 ± 149 mL/min; P = 0.041) or 70% V ̇ O 2 max ${{\dot{V}}_{{{{\mathrm{O}}}_2}\max }}$ EqEE (∆127 ± 177 mL/min; P = 0.004). Therefore, aerobic exercise resulted in both intensity- and dose-dependent effects on acute post-exercise ICA blood flow whereby vigorous intensity exercise provoked a larger increase in ICA blood flow compared to light intensity exercise when performed at a higher dose.

Valoctocogene roxaparvovec gene therapy provides durable haemostatic control for up to 7 years for haemophilia A.

INTRODUCTION: Valoctocogene roxaparvovec is an adeno-associated virus vector serotype 5 (AAV5)-mediated gene therapy approved for severe haemophilia A (HA). AIM: To report the safety and efficacy of valoctocogene roxaparvovec 7 years after dosing in a phase 1/2 clinical study (NCT02576795). METHODS: Males ≥18 years with severe HA (factor VIII [FVIII] ≤1 international unit [IU]/dL) who were previously receiving exogenous FVIII and had no history of FVIII inhibitors or anti-AAV5 antibodies received valoctocogene roxaparvovec treatment and were followed for 7 (6 × 1013 vg/kg; n = 7) and 6 (4 × 1013 vg/kg; n = 6) years. RESULTS: In the last year, one participant in each cohort reported treatment-related adverse events (AEs): grade 1 (G1) hepatomegaly (6 × 1013), and G1 splenomegaly and G1 hepatic steatosis (4 × 1013). During all follow-up, mean annualized treated bleeds and exogenous FVIII infusion rates were ≥88% lower than baseline values. At years 7 and 6, mean (median) FVIII activity (chromogenic assay) was 16.2 (10.3) and 6.7 (7.2) IU/dL in the 6 × 1013 (n = 5) and 4 × 1013 (n = 4) cohorts, respectively, corresponding to mild haemophilia. Regression analyses of the last year estimated rate of change in FVIII activity was -0.001 and -0.07 IU/dL/week for the 6 × 1013 and 4 × 1013 cohorts, respectively. Two participants (6 × 1013) resumed prophylaxis in year 7: one after a non-treatment-related G4 serious AE of spontaneous internal carotid artery bleed, and the other to manage bleeds and FVIII activity. CONCLUSIONS: The safety and efficacy of valoctocogene roxaparvovec remain generally consistent with previous reports, with good haemostatic control for most participants. Two participants returned to prophylaxis.

Safety and Efficacy of Hybrid Surgery in Chronic Internal Carotid Artery Occlusion: A Systematic Review and Meta-Analysis.

INTRODUCTION: Chronic internal carotid artery occlusion (CICAO) is a common cause of stroke and ischemia recurrence. An increasing number of reports have highlighted the potential of hybrid surgery for treating CICAO. There are few studies, specifically nonrandomized controlled trials, on the safety and effectiveness of hybrid surgery for the treatment of CICAO, so in this study, we hypothesized that hybrid surgery would be safe, have an acceptable complication rate and a high success rate. METHODS: MEDLINE, Embase, Cochrane Library, and Web of Science databases were searched for relevant studies published up to January 30, 2023. The primary endpoint was recanalization rates of occluded vessels, and the secondary endpoint was perioperative death and procedure-related complications. Subgroup analysis focused on the recanalization rates of endovascular intervention (EI) and hybrid surgery, as well as the rates of recanalization below the clinoid segment and at the clinoid segment and beyond. The follow-up visit was conducted at least 3 months after surgery, and stenosis or occlusion recurrence was confirmed by review of CTA or DSA scan. RESULTS: The databases were searched and 1,709 records were identified, of which 16 articles were used in the meta-analysis, and 464 CICAO patients with complete data who underwent hybrid surgery were enrolled. Hybrid surgery was associated with higher success rates (RD = 0.87, 95% CI [0.84-0.91], p < 0.00001) than EI (OR = 4.71, 95% CI [2.32-9.56], p < 0.0001). The procedural success rate in the below-clinoid segment group was significantly higher than that in the clinoid segment and beyond group (OR = 13.76, 95% CI [5.31-35.66], p < 0.00001). The total periprocedural complication rate was low (RD = 0.11, 95% CI [0.07-0.15], p < 0.00001 and RD = 0.04, 95% CI [0.00-0.07], p = 0.03). Target vessel restenosis or reocclusion occurred in 35 patients (8%) during the follow-up period (RD = 0.08, 95% CI [0.04-0.12], p < 0.0001). CONCLUSION: Hybrid surgery is the combination of the advantages of open surgery and EI, has a high success rate and a low risk of recurrence of stenosis and occlusion in the long term. Randomized controlled trials on hybrid surgery for internal carotid artery occlusion are necessary.

Association of diabetes and white blood cell count with stroke in patients with carotid artery dissection.

BACKGROUND: Carotid artery dissection is an important cause of stroke. However, the predictors of ischemic stroke in patients with carotid artery dissection are controversial. The study aimed to analyze the predictors of ischemic stroke in patients with carotid artery dissection through retrospective medical records. METHODS: Data of discharged patients diagnosed with carotid artery dissection during 2019-2023 were retrospectively collected. Based on the occurrence of ischemic stroke, the patients were divided into the ischemic stroke or non-ischemic stroke groups. Based on the results of univariate analyses, variables with an associated P value < 0.05 were introduced into the multivariable logistic regression analysis. . RESULTS: A total of 165 patients were included in the study, with an average age of 55.00 (48.00, 66.00) years, including 86 patients with internal carotid artery dissection and 79 patients with vertebral artery dissection. Ischemic stroke occurred in 69 patients with carotid artery dissection. Multivariate logistic regression analysis indicated that diabetes (odds ratio [OR]: 3.144, 95% confidence interval [CI]: 1.552-6.508, P<0.002) and high white blood cells count (OR: 1.157, 95% CI: 1.02-1.327,P = 0.028) were related to the incidence of ischemic stroke in patients with carotid artery dissection. CONCLUSION: Ischemic stroke caused by carotid artery dissection causes severe damage to the nervous system. This study found that diabetes and high white blood cells count were associated with the incidence of ischemic stroke in patients with carotid artery dissection. Therefore, monitoring and controlling blood glucose levels and infections is essential in patients with carotid artery dissection to reduce the incidence of stroke.

Prevalence and clinical implications of calcification in internal carotid artery stenosis: a retrospective study.

BACKGROUND: Calcification is common in advanced atheromatous plaque, but its clinical significance remains unclear. This study aimed to assess the prevalence of plaque calcification in the moderate-to-severe internal carotid artery stenosis and investigate its relationship with ipsilateral ischemia. METHODS: The retrospective study included 178 patients detected with proximal internal carotid artery (pICA) stenosis of ≥ 50% on multidetector computed tomography at Zhejiang Hospital from January 2019 to March 2023. Association between plaque calcification characteristics (calcification thickness, position, type, circumferential extent, calcium volume and calcium score) and ipsilateral cerebrovascular events was analyzed. RESULTS: The 178 patients (mean age 71.24 ± 10.02 years, 79.78% males) had 224 stenosed pICAs overall. Plaque calcification was noted in 200/224 (89.29%) arteries. Calcification rates were higher in older age-groups. Calcification volume (r = 0.219, p < 0.001) and calcification score (r = 0.230, p < 0.001) were correlated with age. Ipsilateral ischemic events were significantly more common in the noncalcification group than in the calcification group (χ2 = 4.160, p = 0.041). The most common calcification type was positive rim sign calcification (87/200, 43.50%), followed by bulky calcification (66/200, 33.00%); both were significantly associated with ischemic events (χ2 = 10.448, p = 0.001 and χ2 = 4.552, p = 0.033, respectively). Calcification position, thickness, and circumferential extent, and calcification volume and score, were not associated with ischemic events. In multivariate analysis, positive rim signs (OR = 2.795, 95%CI 1.182-6.608, p = 0.019) was an independent predictor of ischemic events. CONCLUSIONS: Plaque calcification in proximal internal carotid artery is common, and prevalence increases with age. Calcification characteristics could be predictive of ipsilateral ischemic events. The positive rim sign within plaque is a high-risk factor for a future ischemic event.

Evaluation of collateral circulation in patients with internal carotid artery occlusion: A clinical and ultrasonographic multicenter study.

BACKGROUND: Internal carotid artery (ICA) occlusion is the major cause of ischemic stroke. The effect of collateral vessels on cerebral hemodynamics in ICA occlusion remains unclear. This study investigated the correlation between collateral vessels and the peak systolic velocity of the middle cerebral artery (MCA) in patients with ICA occlusion. METHODS: The relevant collateral vessels included the anterior communicating (ACoA), posterior communicating (PCoA), and internal-external carotid (IECCA) arteries, respectively. Patients with unilateral ICA occlusion (n = 251) underwent transcranial Doppler imaging to detect the peak systolic velocity (PSV) of the MCA and other intracranial arteries. The clinical symptoms were assessed using the National Institutes of Health Stroke Scale (NIHSS). RESULTS: Patients with ACoA collaterals had significantly higher PSVMCA scores and significantly lower NIHSS scores than those without ACoA collaterals (p < 0.001). Patients without any notable collaterals and those with only IECCA had the lowest PSVMCA and highest NIHSS scores. The PSVMCA and NIHSS scores were negatively correlated (r = -0.566, p < 0.001). CONCLUSION: Collateral circulation patency in unilateral ICA occlusion was closely associated with clinical symptoms, and patients with ACoA collaterals may have favorable outcomes. (ClinicalTrials.gov Identifier: NCT02397655).

Idiopathic extracranial internal carotid artery vasospasm: case report and systematic review.

BACKGROUND: Idiopathic extracranial internal carotid artery vasospasm (IEICAV) is characterized by spontaneous, recurrent, and reversible vasoconstriction of the cervical internal carotid artery (ICA). The etiology remains elusive, and no effective treatment has been established. The present study presents a case of recurrent IEICAV with migraine-like symptoms and conduct a systematic review on IEICAV. METHODS: A retrospective analysis was conducted on a case involving medical history, radiological data, treatment, and outcomes. A systematic review of published IEICAV cases was conducted through database searching in PubMed, Embase, and Web of Science from inception until May 2024. RESULTS: A 22-year-old female with recurrent headaches, blurred vision, and aphasia was diagnosed with bilateral IEICAV through angiography. Magnetic resonance imaging demonstrated a novel cerebral infarction during a prolonged episode. Treatment with topiramate successfully controlled recurrence in a 5-month follow-up. The systematic review included 36 IEICAV cases reported by literature. Bilateral involvement of extracranial ICAs was observed in 25 (69.4%) cases. Cerebral infarction was identified in 31 (88.9%) cases. Despite various treatment attempts including vasodilators, antiplatelet, anticoagulants, glucocorticoids, and other medical or surgical intervention, the recurrent rate increased in 5 (13.9%) cases, decreased in 10 (27.8%) cases, and remained unchanged in 4 (11.1%) cases. CONCLUSIONS: The elusive mechanism of IEICAV brings great difficulty into managing recurrence. Preventing IEICAV-related infarction related to secondary factors like hypoperfusion may be crucial for maintaining life quality. Further research is essential for advancing treatment strategies and a case-by-case approach is needed in identifying and eliminating possible triggers for vasospastic episodes.

Quantification of neurovascular compliance with retrospectively gated phase-contrast MRI.

OBJECTIVE: Neurovascular compliance (NVC) is the change in the brain's arterial tree blood volume, ΔV, divided by the change in intra-vascular blood pressure, ΔP, during the cardiac cycle. The primary aim of this work was to evaluate the performance of MRI measurement of NVC obtained from time-resolved measurements of internal carotid artery (ICA) and vertebral artery (VA) flow rates. A secondary aim was to explore whether NVC could be estimated from common carotid (CCA) flow in conjunction with prior knowledge of mean ICA and VA fractional flow rates, given the small cross-section of ICA and VA in some populations, in particular small children. METHODS: ΔV was quantified from the blood flow rate measured at the ICA and VA for actual NVC derivation. It was further estimated from individually measured CCA flow rate and mean flow fractions ICA/CCA and VA/CCA (which could alternatively be obtained from literature data), to yield estimated NVC. Time-resolved blood flow rate in CCA, ICA and VA was obtained via retrospectively-gated 2D PC-MRI at 1.5 T in healthy subjects (N = 16, 8 women, mean age 36 ± 13 years). ΔP was determined via a brachial pressure measurement. RESULTS: Actual and estimated mean NVC were 27 ± 15 and 38 ± 15 µL/mmHg, respectively, and the two measurements were strongly correlated (r = 0.80; p = 0.0002) with test-retest intra-class correlation coefficients of 0.964 and 0.899. CONCLUSION: Both methods yielded excellent retest precision. In spite of a large bias, actual and estimated NVC were strongly correlated.

Risk factors of internal carotid artery stenosis in patients with proliferative diabetic retinopathy: an analysis using optical coherence tomography and optical coherence tomography angiography.

BACKGROUND: This research investigates the correlation between the severity of internal carotid artery (ICA) stenosis and retinal parameters in patients with proliferative diabetic retinopathy (PDR), aiming to uncover potential risk factors. METHODS: A retrospective analysis of 68 patients (136 eyes) diagnosed with bilateral PDR from January 1, 2017, to December 31, 2021, was conducted. Carotid artery stenosis (CAS) was assessed using neck computed tomography angiography (CTA) and carotid duplex ultrasound (CDUS), with stenosis classified into two groups: normal (group 1) and mild or above (group 2), based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Optical coherence tomography (OCT) and OCT angiography (OCTA) measured several retinal parameters, including sub foveal choroidal thickness (SFCT), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, vessel density (VD), and foveal avascular zone (FAZ) area. Statistical analyses determined correlations between ICA degrees and retinal parameters. RESULTS: This study showed significant differences between groups in total VD, FAZ area, total RNFL thickness, and temporal RNFL thickness, indicating that patients with more severe ICA stenosis had noticeable retinal changes. Other parameters such as hyperlipidemia, total cholesterol levels, and intraocular pressure (IOP) also differed significantly, while no notable differences were observed in SFCT, central VD, average GCIPL, and superior, nasal, and inferior RNFL thickness. CONCLUSION: The study findings highlight retinal changes, such as an increased FAZ area, decreased total VD, and a total and thinner temporal RNFL, which suggest the need for carotid artery evaluation in patients. These findings have important clinical implications for the need for carotid work up in patients with PDR.

Clipping of Anterior Circulation Aneurysms: Operative Instructions and Safety Rules for Young Cerebrovascular Surgeons.

INTRODUCTION: Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever. MATERIALS AND METHODS: We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations. RESULTS: We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping. CONCLUSION: In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Hemorrhage at high altitude: impact of sustained hypobaric hypoxia on cerebral blood flow, tissue oxygenation, and tolerance to simulated hemorrhage in humans.

With ascent to high altitude (HA), compensatory increases in cerebral blood flow and oxygen delivery must occur to preserve cerebral metabolism and consciousness. We hypothesized that this compensation in cerebral blood flow and oxygen delivery preserves tolerance to simulated hemorrhage (via lower body negative pressure, LBNP), such that tolerance is similar during sustained exposure to HA vs. low altitude (LA). Healthy humans (4F/4 M) participated in LBNP protocols to presyncope at LA (1130 m) and 5-7 days following ascent to HA (3800 m). Internal carotid artery (ICA) blood flow, cerebral delivery of oxygen (CDO2) through the ICA, and cerebral tissue oxygen saturation (ScO2) were determined. LBNP tolerance was similar between conditions (LA: 1276 ± 304 s vs. HA: 1208 ± 306 s; P = 0.58). Overall, ICA blood flow and CDO2 were elevated at HA vs. LA (P ≤ 0.01) and decreased with LBNP under both conditions (P < 0.0001), but there was no effect of altitude on ScO2 responses (P = 0.59). Thus, sustained exposure to hypobaric hypoxia did not negatively impact tolerance to simulated hemorrhage. These data demonstrate the robustness of compensatory physiological mechanisms that preserve human cerebral blood flow and oxygen delivery during sustained hypoxia, ensuring cerebral tissue metabolism and neuronal function is maintained.

A nomogram predicting the relationship between recanalization time and successful endovascular recanalization of non-acute internal carotid artery occlusion in a Chinese population.

Different recanalization times for endovascular interventions may affect the success of non-acute internal carotid artery occlusion procedures. Nomograms can provide personalized and more accurate risk estimates based on predictive values. Therefore, we developed a nomogram to predict the probability of success of endovascular recanalization procedures for non-acute internal carotid artery occlusion. We performed a single-center retrospective analysis of data collected from patients who underwent endovascular treatment for non-acute internal carotid artery occlusion between January 2015 and December 2022. Multifactorial logistic regression analyses were performed to identify independent predictors affecting the success rate of non-acute internal carotid artery occlusion procedures and to create nomograms. The model was differentiated and calibrated using the area under the ROC curve (AUC-ROC) and calibration plots. Internal validation of the model was performed by using resampling (1000 replications). In total, 46 patients were identified and a total of 39 patients met the study criteria. Predictors in the nomogram included vascular occlusion proximal morphology, reversed flow of the ophthalmic artery, and recanalization time. The model showed good resolution with an ROC area of 0.917 (95% CI: 0.814-0.967). The nomogram can be used to personalize, visualize, and accurately predict the surgical success of endovascular treatment of non-acute internal carotid artery occlusion.

Prefrontal Cortex Oxygenation During Walking in an Acute Ischaemic Stroke Patient with Severe Internal Carotid Artery Stenosis: A Case Report.

This study investigated the oxygenation in the prefrontal cortex (PFC) during walking in a 75-year-old male patient in the acute phase of a left frontal lobe cerebral infarction complicated by severe left internal carotid artery stenosis. The patient regained independent ambulation on the fifth day after the onset of symptoms, and the study was conducted on the eighth day after the onset of symptoms. The patient rested for 10 s before walking for 70 s. Then he rested for 60 s. The levels of oxyhaemoglobin (O2Hb), deoxyhaemoglobin (HHb), and total haemoglobin (THb) in the PFC were quantified during the rest and walking phases using a wearable near-infrared spectroscopy device. Comparative analysis with baseline values during rest revealed decreases in the O2Hb, HHb, and THb in both hemispheres of the PFC during walking (O2Hb: -19.76/ -14.88 µmol/L, HHb: -1.18/ -2.00 µmol/L, THb: -20.96/ -16.88 µmol/L, right/left, respectively). The recovery of the O2Hb was delayed by 15.8 seconds in the affected hemisphere. These findings support the effectiveness of wearable NIRS for the evaluation of cerebral oxygenation during rehabilitation in patients with acute stroke to facilitate evaluations and individualise patient care.

Hybrid Surgery for symptomatic chronic internal carotid artery occlusion: a single-center experience.

BACKGROUND: Patients with symptomatic chronic internal carotid artery occlusion (ICAO) face a high risk of recurrent stroke despite receiving aggressive medical therapy. This study aimed to evaluate the effectiveness and safety of hybrid surgery in treating symptomatic chronic ICAO. METHODS: This retrospective case series was conducted at a single center. From January 2019 to December 2022, patients with symptomatic chronic ICAO who underwent hybrid surgery were included. We collected baseline data, lesion characteristics, revascularization rates, perioperative complications, and follow-up outcomes. RESULTS: The study enrolled 27 patients, comprising 22 males and 5 females, with symptomatic chronic ICAO. The hybrid surgery achieved a technical success rate of 100% for revascularization (n = 27), with a perioperative complication rate of 14.8% (n = 4). Following a median follow-up of 6.0 months (IQR, 4-10), 21 patients underwent a DSA or CT angiography reexamination, confirming a vascular patency rate of 90.5% (n = 19). One patient required surgery for severe in-stent restenosis, and another experienced asymptomatic occlusion. Clinical follow-ups were conducted for all 26 patients; no new strokes were reported in the qualifying artery territory, with 13 patients scoring 0, 12 scoring 1, and 1 scoring 2 on the mRS. CONCLUSION: Although hybrid surgery represent a promising option for treating chronic ICAO, they are also associated with a relatively high incidence of treatment-related complications. The application of composite surgery should be based on standardized technical guidelines and the careful selection of patients who are genuinely at high risk for recurrent strokes.

How I do it? Surgical clipping of a large right internal carotid artery-superior hypophyseal artery aneurysm.

BACKGROUND: Microsurgery alone often proves to be challenging in treating paraclinoid internal carotid artery (ICA) aneurysms, which are known for their complex anatomy. METHOD: A 53-year-old female with a large right ICA-superior hypophyseal artery (SHA) aneurysm underwent clipping repair. Mixed reality technology was utilized in the preoperative planning and anatomical study. During the surgery, the anterior clinoid process was removed intradurally to improve access to the aneurysm neck. The aneurysm was then secured with a long curved clip. The patient's recovery was successful without any complications. CONCLUSION: This report aims to shed light on the intricacies involved in clipping ICA-SHA aneurysms.

Anatomical variations of origin of the internal carotid artery: Report of two cases and systematic review of the literature.

BACKGROUND: Anatomical variations of origin of the internal carotid artery (ICA) are very uncommon and may pose a diagnostic and therapeutic challenge. OBJECTIVE: We report a case of direct origin of the right ICA from the innominate artery (aplasia of common carotid artery) and a case of duplication of right ICA in healthy patients who performed duplex ultrasound (DUS) for primary cardiovascular prevention screening. METHODS: In both cases, the ultrasound scan was performed both in a transverse plane and on the longitudinal axis, and in one of the two cases, a computed tomography angiography was performed to confirm the diagnosis. A review of the current literature about anatomical variations of origin of carotid arteries was also performed. RESULTS: The most frequent congenital anomaly is represented by the aplasia of the CCA, followed by the agenesis and by the duplication of the ICA. In most cases, the anomaly is discovered occasionally and symptoms are aspecific. Diagnosis is usually confirmed through a multimodality imaging approach, including DUS of extracranial carotid arteries, magnetic resonance imaging (MRI), and computed tomographic angiography. In most cases, treatment was conservative, with pharmacological therapy aimed at the symptoms. CONCLUSION: The recognition of such variations is mandatory, particularly when the patient needs a surgical treatment that may involve the vessel with the anatomical variations.

Application and diagnostic points of carotid artery ultrasound in the detection of internal carotid artery absence: Analysis of 16 cases and literature review.

OBJECTIVE: To summarize the ultrasound diagnostic key points and imaging characteristics of absence of the internal carotid artery (ICA), and to explore the application value of carotid artery ultrasound in the diagnosis of ICA absence. METHODS: Sixteen patients diagnosed with ICA absence at our hospital were retrospectively analyzed. Clinical data, ultrasound images, and other relevant imaging data were reviewed. The ultrasound diagnostic key points and related imaging characteristics of ICA absence were summarized. Combined with a literature review, the application of carotid artery ultrasound in the diagnosis of ICA absence was discussed. RESULTS: Among the 16 patients, there were 10 males and 6 females ages ranging from 13 to 80 years. Among them, 5 patients had a history of cerebral infarction, 1 patient had a history of subarachnoid hemorrhage, and 10 patients had no history of stroke. Among the 16 patients, there were 10 left-sided lesions, 5 right-sided lesions, and 1 bilateral lesion. Three patients had concomitant aneurysms. Carotid ultrasound examinations in all 16 ICA absent patients revealed that a significantly slender common carotid artery (CCA) diameter compared to the contralateral (3.91 ± 0.73 vs. 6.92 ± 1.42, p < 0.001). On the side of ICA absence, the bifurcation of the carotid artery was not detected, with the CCA directly continuing as a single artery (external carotid artery, ECA). The temporal superficial artery percussion test was positive in all cases, and the blood flow spectrum of the single artery (ECA) on the side of the absent ICA showed a serrated pattern during diastole. On the side where the ICA was absent, the blood flow spectrum morphology of the CCA and ECA was consistent. Based on other relevant imaging examinations, the patients were classified into Lie types: A (10 cases), B (2 cases), C (1 case), D (1 case), and 2 cases were unclassified. CONCLUSION: Carotid artery ultrasound has the advantages of easy operation, affordability, non-invasiveness, and capable of dynamic and high repeatability. Compared to other imaging examinations, it can provide more evidence for the diagnosis of ICA absence, and is suitable for widespread application and promotion.