Background: The role of regional hemodynamics in the intracranial aneurysmal formation, growth, and rupture has been widely discussed based on numerical models over the past decades. Variation of the circle of Willis (CoW), which results in hemodynamic changes, is associated with the aneurysmal formation and rupture. However, such correlation has not been further clarified yet. The aim of this systematic review is to investigate whether simulated hemodynamic indices of the CoW are relevant to the formation, growth, or rupture of intracranial aneurysm. Methods: We conducted a review of MEDLINE, Web of Science, and EMBASE for studies on the correlation between hemodynamics indices of the CoW derived from numerical models and intracranial aneurysm up to December 2020 in compliance with PRISMA guidelines. Results: Three case reports out of 1046 publications met our inclusion and exclusion criteria, reporting 13 aneurysms in six patients. Eleven aneurysms were unruptured, and the state of the other two aneurysms was unknown. Wall shear stress, oscillatory shear index, von-Mises tension, flow velocity, and flow rate were reported as hemodynamic indices. Due to limited cases and significant heterogeneity between study settings, meta-analysis could not be performed. Conclusion: Numerical models can provide comprehensive information on the cerebral blood flow as well as local flow characteristics in the intracranial aneurysm. Based on only three case reports, no firm conclusion can be drawn regarding the correlation between hemodynamic parameters in the CoW derived from numerical models and aneurysmal formation or rupture. Due to the inherent nature of numerical models, more sensitive analysis and rigorous validations are required to determine its measurement error and thus extend their application into clinical practice for personalized management. Prospero registration number: CRD42021125169.
The coronavirus disease 2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been described to predispose to thrombotic disease in both the venous and arterial circulations. We report four cases of an acute arterial occlusion in COVID-19 patients and literature review on the occurrence of arterial thrombosis in patients with COVID-19. Our findings demonstrate that physicians should be vigilant for signs of thrombotic complications in both hospitalized and new COVID-19 patients.
ObjectiveCarotid endarterectomy (CEA) aims to reduce the risk of stroke in patients with atherosclerotic carotid disease. Preoperative risk assessments that predict complications are needed to optimize the care in this patient group. The current approach, namely relying solely on symptomatology and degree of stenosis, is outdated and calls for innovation. The Agatston calcium score was applied in several vascular specialties to assess cardiovascular risk profile but has been little studied in carotid surgery. It is hypothesized that a higher calcium burden at initial presentation equates to a worse prognosis attributable to an increased cerebrovascular and cardiovascular risk profile. The aim was to investigate the association between preoperative ipsilateral calcium score and postoperative all-cause mortality in patients undergoing CEA.MethodsThis single-center retrospective cohort study included 89 patients who underwent CEA at a tertiary referral center between 2010 and 2018. Preoperative calcium scores were measured on contrast-enhanced computed tomography images with patient-specific Hounsfield thresholds at the level of the carotid bifurcation. The association between these calcium scores and all-cause mortality was analyzed using multivariable adjusted Cox proportional hazard analysis.ResultsCox proportional hazard analysis demonstrated a significant association between preoperative ipsilateral carotid calcium score and all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.16; P = .003). After adjusting for age, preoperative estimated glomerular filtration rate, and diabetes mellitus, a significant association remained (hazard ratio, 1.07; 95% confidence interval, 1.00-1.15; P = .05).ConclusionsA higher calcium burden was predictive of worse outcome, which might be explained by an overall poorer health status. These results highlight the potential of calcium measurements in combination with other traditional risk factors, for preoperative risk assessment and thus for improved patient education and care.
Arterial spin labelling (ASL) is an MRI technique for measuring perfusion at the brain tissue level. The aim of the study was to investigate cerebrovascular reactivity (CVR) at brain-tissue level in patients with an internal carotid artery (ICA) occlusion by combining ASL-MRI with a vascular challenge, and determine whether the CVR varies within the perfusion territory of the brain-feeding arteries.
Methods
Sixteen patients with a symptomatic ICA occlusion and 16 age-matched healthy control subjects underwent perfusion and perfusion-territory selective ASL-MRI before and after acetazolamide administration. CVR was assessed throughout the brain in the grey matter supplied by the unaffected asymptomatic ICA and the basilar artery.
Results
Cerebral blood flow increased (p<0.01) in all perfusion territories after acetazolamide in the patients and controls. In the tissue supplied by the unaffected contralateral ICA, CVR was lower in the tissue supplied by the unaffected contralateral ICA in the patients when compared with the controls (22.8±16.1 vs 54.2±13.1%; mean difference, −31.5%, 95% CI −42.1 to −20.8). Within the perfusion territory of the unaffected ICA, the CVR was lower in the brain tissue on the side of the occluded ICA than on the side of the unaffected ICA (13.5±20.4 vs 26.2±16.0%; paired mean difference −12.5%, 95% CI −20.3 to −4.7).
Conclusion
ASL-MRI can assess impaired cerebrovascular reactivity at the brain-tissue level in patients with a symptomatic ICA occlusion. Assessment of CVR with ASL-MRI may help to identify the tissue most at risk for future stroke and as such may guide medical treatment.
BACKGROUND: The effectiveness of intravenous thrombolysis (IVT) before endovascular treatment (EVT) has been investigated in randomized trials and meta-analyses. These studies mainly concerned anterior circulation occlusions. We aimed to investigate clinical, technical, and safety outcomes of IVT before EVT in posterior circulation occlusions in a nationwide registry. METHODS: Patients were included from the MR CLEAN Registry (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), a nationwide, prospective, multicenter registry of patients with acute ischemic stroke due to a large intracranial vessel occlusion receiving EVT between 2014 and 2019. All patients with a posterior circulation occlusion were included. Primary outcome was a shift toward better functional outcome on the modified Rankin Scale at 90 days. Secondary outcomes were favorable functional outcome (modified Rankin Scale scores, 0–3), occurrence of symptomatic intracranial hemorrhages, successful reperfusion (extended Thrombolysis in Cerebral Ischemia ≥2B), first-attempt successful reperfusion, and mortality at 90 days. Regression analyses with adjustments based on univariable analyses and literature were applied. RESULTS: A total of 248 patients were included, who received either IVT (n=125) or no IVT (n=123) before EVT. Results show no differences in a shift on the modified Rankin Scale (adjusted common odds ratio, 1.04 [95% CI, 0.61–1.76]). Although symptomatic intracranial hemorrhages occurred more often in the IVT group (4.8% versus 2.4%), regression analysis did not show a significant difference (adjusted odds ratio, 1.65 [95% CI, 0.33–8.35]). Successful reperfusion, favorable functional outcome, first-attempt successful reperfusion, and mortality did not differ between patients treated with and without IVT. CONCLUSIONS: We found no significant differences in clinical, technical, and safety outcomes between patients with a large vessel occlusion in the posterior circulation treated with or without IVT before EVT. Our results are in line with the literature on the anterior circulation.
We report the case of a 16-year-old boy with primary sclerosing cholangitis associated with inflammatory bowel disease who was initially treated and controlled pharmacologically. He underwent living donor liver transplantation (LDLT) after he developed progressive biliary tract abnormalities and portal hypertension accompanied by recurrent bile duct infections. Two months following LDLT, the hepaticojejunostomy anastomosis became occluded and it was treated surgically. Few weeks later, an increase in drain production persisted without focus; therefore, further diagnostic tests were conducted which proved the recurrence of biliary cast. Under sonographic guidance, external drainage of bile was carried out by percutaneous transhepatic cholangiography and drainage. In total, our patient underwent 5 interventions under general anesthesia and clinically, our patient's general condition improved, and he gained weight. Minimally invasive procedures such as percutaneous transhepatic cholangiography and drainage and balloon dilation are safe and effective, but may require several attempts before being successful.
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