Measuring global cerebrovascular pulsatility transmission using 4D flow MRI.

Pulse wave encephalopathy (PWE) is hypothesised to initiate many forms of dementia, motivating its identification and risk assessment. As candidate pulsatility based biomarkers for PWE, pulsatility index and pulsatility damping have been studied and, currently, do not adequately stratify risk due to variability in pulsatility and spatial bias. Here, we propose a locus-independent pulsatility transmission coefficient computed by spatially tracking pulsatility along vessels to characterise the brain pulse dynamics at a whole-organ level. Our preliminary analyses in a cohort of 20 subjects indicate that this measurement agrees with clinical observations relating blood pulsatility with age, heart rate, and sex, making it a suitable candidate to study the risk of PWE. We identified transmission differences between vascular regions perfused by the basilar and internal carotid arteries attributed to the identified dependence on cerebral blood flow, and some participants presented differences between the internal carotid perfused regions that were not related to flow or pulsatility burden, suggesting underlying mechanical differences. Large populational studies would benefit from retrospective pulsatility transmission analyses, providing a new comprehensive arterial description of the hemodynamic state in the brain. We provide a publicly available implementation of our tools to derive this coefficient, built into pre-existing open-source software.

How I do it: operative nuances of the Encephalo-Duro-Mio-Synangiosis (EDMS) technique for pediatric moyamoya disease and syndrome.

BACKGROUND: Moyamoya disease, a progressive occlusive arteriopathy mainly affecting the supraclinoid internal carotid artery, leads to abnormal "Moyamoya vessels" and ischemic events in children due to decreased cerebral blood flow. Surgery, especially indirect revascularization, is suggested for pediatric Moyamoya cases. METHOD: We present the Encephalo-Duro-Mio-Synangiosis (EDMS) technique, illustrated with figures and videos, based on 14 years' experience performing 71 surgeries by the senior author (SGJ) and the Moyamoya Interdisciplinary Workteam at "Prof. Dr. J. P. Garrahan" Pediatric Hospital. CONCLUSION: EDMS is a simple and effective treatment for Moyamoya disease, enhancing procedure precision and safety, reducing associated risks, complications, and improving clinical outcomes.

[Treatment strategy of carotid blowout syndrome after radiotherapy for nasopharyngeal carcinoma].

Objective:To investigate the treatment of internal carotid artery rupture after radiotherapy for nasopharyngeal carcinoma. Methods:The clinical data of 7 patients with internal carotid artery rupture after radiotherapy for nasopharyngeal carcinoma from March 2020 to March 2023 were retrospectively analyzed. Results:Skull base osteonecrosis with infection occurred in 4 cases, and tumor recurrence with infection in 3 cases. DSA showed that internal carotid artery rupture was located in the internal carotid artery petrosal segment in 6 cases, and in the paravicular segment in 1 case. Balloon occlusion test（BOT） was performed in 6 patients, of which 3 passed and 3 failed. Vascular treatment included internal carotid artery embolization（4 cases）, false aneurysm embolization 1 case（rebleeding）, coated stent 1 case（rebleeding）, muscle compression during operation（1 case）. Patients with rebleeding received high-flow bypass. Three cases developed cerebral infarction after embolization without severe sequelae after treatment, and no death occurred within 90 days. After bleeding control, all 3 patients with cranial base necrosis received surgical treatment to remove the necrotic bone and tissue flap repair, and 1 patient with recurrence received gamma knife and targeted therapy, 1 patient received immune and surgical therapy, and 1 patient received immune and targeted therapy. Conclusion:Rupture and hemorrhage of internal carotid artery after radiotherapy is related to tumor invasion, tissue injury and local infection after radiotherapy. For those caused by tumor invasion, it is recommended to sacrifice the responsible vessels. For those caused by infection, emergency surgery is recommended and blood vessels preserved. Emergency vascular occlusion remains a life-saving option.

[An anatomical road map of the parapharyngeal internal carotid artery in lateral and endoscopic ventral approaches].

Objective:To describe the road map of the lateral and endoscopic ventral approaches for the pharyngeal segment of the internal carotid artery, propose a sub-segmentation scheme, systematically and comprehensively understand its anatomical details and relationships with the surrounding structures. Methods:Five fresh cadaveric head specimens（10 sides in total） were dissected through lateral and endoscopic ventral approaches to evaluate the anatomical details of the parapharyngeal internal carotid artery and its relationship with the surrounding structures. Results:From the bifurcation of the common carotid artery to the vertical part of the internal carotid artery, alongside the direction of blood flow, the parapharyngeal internal carotid artery passes through four distinct anatomical tissues. Based on this, the parapharyngeal internal carotid artery can be divided into four sub-segments: nerve, muscle, fascia and osseous sub-segments. The boundaries and important adjacent structures of each segment are described in detail. Conclusion:The anatomical road map of the parapharyngeal internal carotid artery and the sub-segmentation scheme serving as a practical guide to navigate modular endoscopic skull base surgery of the parapharyngeal space while reduce the risk of internal carotid artery injury.

Anterior clinoidectomy in low lying internal carotid artery-posterior communicating artery aneurysm.

BACKGROUND: At times, a regulation internal carotid artery-posterior communicating artery junction (ICA-P-Comm) aneurysm becomes a surgical hurdle owing to its close proximity to the anterior clinoid process, an immovable ICA and a concealed dominant P-Comm artery arising from the aneurysm neck. METHOD: A 70 year old patient with a low lying ICA-P-Comm aneurysm underwent a "tailored" intradural clinoidectomy for aneurysm clipping. CONCLUSION: A tailored anterior clinoidectomy to expose "just enough" allows a proximal ICA control in a suitable area, mobility of an atherosclerotic ICA and exposes the P-Comm artery origin which are essential in safe clipping of these aneurysms.

Management of Incidental Carotid Cave Aneurysm.

BACKGROUND: Incidental diagnosis of saccular aneurysms is more common with the advent of imaging techniques. Because of the severe morbidity and mortality that they can cause, treatment is chased for them, either microsurgical treatment or endovascular, even when they are diagnosed incidentally. Carotid cave aneurysms are rare, and they seem to have a more benign course compared to other intracranial aneurysms, probably related to the physical enveloping effect of the surrounding structures. Yet, their microsurgical treatment is a serious challenge technically for the neurosurgeon, with its severe morbidity and mortality for the patient. Endovascular techniques have their risks, too. PURPOSE: In this paper, we analyzed and presented our series of incidentally diagnosed carotid cave aneurysms. MATERIALS AND METHODS: The age, gender of patients, the size, laterality, and MR angiographic follow-up of aneurysms were reported. Their clinical results were noted. RESULTS: Fifty-six patients who had incidentally been diagnosed with 59 carotid cave aneurysms were followed up. No patient was microsurgically treated, but 15 patients had endovascular treatment for 15 aneurysms. The mean size of 15 treated aneurysms was 4.6 ± 2.1 (range = 2-10) mm, and it was 3.0 ± 1.5 (range = 1.7-10) mm for the untreated aneurysms (n = 44). There was no significant difference between the follow-up times of the treated and untreated groups (P = 0.487). The median follow-up of 59 aneurysms in 56 patients was 52 (mean = 49.6 ± 27.9, range = 1-124) months, with a total follow-up of 244 aneurysm years. None of the patients had subarachnoid hemorrhage related to carotid cave aneurysms during follow-up, and none of the aneurysms had shown growth. Two patients who had endovascular treatment had ischemic complications with minor neurologic deficits. CONCLUSION: Follow-up can be a reasonable option for the incidental aneurysms that are located and confined to the carotid cave. Additionally, TOF might be a reliable method for follow-up imaging of carotid cave aneurysms.

Acute Glaucoma Following Internal Carotid Artery Stenting: A Rare But Serious Complication of Ocular Ischemic Syndrome.

Acute glaucoma following carotid artery recanalization is a rare but severe complication of underlying ocular ischemic syndrome. We present a case of a 71-year-old woman with ocular ischemic syndrome and severe stenosis of the right internal and external carotid artery undergoing carotid artery stenting. Immediate postprocedural angiography showed pronounced reperfusion of the ophthalmic artery. Subsequently, the patient developed vision-threatening acute glaucoma despite treatment with acetazolamide. Monitoring of intraocular pressure is important in patients who are at risk of developing ocular ischemic syndrome because of internal carotid artery stenosis. Interventionalists should also assess the degree of vascular collateralization from the external carotid artery.

Significance of atherosclerotic plaque location in recanalizing non-acute long-segment occlusion of the internal carotid artery.

To investigate the significance of atherosclerotic plaque location in hybrid surgery comprising both endovascular recanalization approaches and carotid endarterectomy for symptomatic atherosclerotic non-acute long-segment occlusion of the internal carotid artery (ICA), 162 patients were enrolled, including 120 (74.1%) patients in the proximal plaque group and 42 (25.9%) in the distal plaque group. Surgical recanalization was performed in all patients, with successful recanalization in 119 (99.2%) patients in the proximal and 39 (92.9%) in the distal plaque group. The total successful recanalization rate was 97.5% (158/162) with a failure rate of 2.5% (4/162). Periprocedural complications occurred in 5 (4.2% or 5/120) patients in the proximal plaque group, including neck infection in two (1.7%), recurrent nerve injury in 1 (0.8%), and laryngeal edema in 2 (1.7%), and 2 (4.8%) in the distal plaque group, including femoral puncture infection in 2 (4.8%). No severe complications occurred in either group. Univariate analysis showed plaque location was a significant (P = 0.018) risk factor for successful recanalization, and multivariate analysis indicated that the plaque location remained a significant independent risk factor for recanalization success (P = 0.017). In follow-up 6-48 months after the recanalization surgery, reocclusion occurred in two (2.8%) patients in the proximal plaque group and 4 (13.3%) in the distal plaque group. In conclusion, although hybrid surgery achieves similar outcomes in patients with ICA occlusion caused by either proximal or distal atherosclerotic plaques, plaque location may be a significant risk factor for successful recanalization of symptomatic non-acute long-segment ICA occlusion.

Using DFT on ultrasound measurements to determine patient-specific blood flow boundary conditions for computational hemodynamics of intracranial aneurysms.

Boundary conditions (BCs) is one pivotal factor influencing the accuracy of hemodynamic predictions on intracranial aneurysms (IAs) using computational fluid dynamics (CFD) modeling. Unfortunately, a standard procedure to secure accurate BCs for hemodynamic modeling does not exist. To bridge such a knowledge gap, two representative patient-specific IA models (Case-I and Case-II) were reconstructed and their blood flow velocity waveforms in the internal carotid artery (ICA) were measured by ultrasonic techniques and modeled by discrete Fourier transform (DFT). Then, numerical investigations were conducted to explore the appropriate number of samples (N) for DFT modeling to secure the accurate BC by comparing a series of hemodynamic parameters using in-vitro validated CFD modeling. Subsequently, a comprehensive comparison in hemodynamic characteristics under patient-specific BCs and a generalized BC based on a one-dimensional (1D) model was conducted to reinforce the understanding that a patient-specific BC is pivotal for accurate hemodynamic risk evaluations on IA pathophysiology. In addition, the influence of the variance of heart rate/cardiac pulsatile period on hemodynamic characteristics in IA models was studied preliminarily. The results showed that N ≥ 16 for DFT model is a decent choice to secure the proper BC profile to calculate time-averaged hemodynamic parameters, while more data points such as N ≥ 36 can ensure the accuracy of instantaneous hemodynamic predictions. In addition, results revealed the generalized BC could overestimate or underestimate the hemodynamic risks on IAs significantly; thus, patient-specific BCs are highly recommended for hemodynamic modeling for IA risk evaluation. Furthermore, this study discovered the variance of heart rate has rare influences on hemodynamic characteristics in both instantaneous and time-averaged parameters under the assumption of an identical blood flow rate.

Ischemic stroke due to stylocarotid artery syndrome: a case report and review.

Stylocarotid artery syndrome (SAS) is a rare variant of Eagle's syndrome that may lead to transient ischemic attack or stroke. The underlying pathophysiological mechanism involves compression of the internal carotid artery by an elongated styloid process (ESP), potentially resulting in vascular occlusion or dissection. An ESP exceeding 2.5 cm is deemed elongated, with a length of 3.0 cm considered clinically significant. Although the prevalence of ESP ranges from 4.0% to 7.3%, symptomatic cases are rare; symptoms are present in only approximately 4.0% of individuals with an ESP. Unlike the typical symptoms of Eagle's syndrome, SAS may not cause pharyngeal discomfort, the sensation of a foreign body in the throat, dysphagia, or facial pain. This absence of characteristic symptoms as well as the development of central nervous system symptoms often leads patients to seek care from neurologists instead of otolaryngologists, increasing the likelihood of misdiagnosis or underdiagnosis. We herein report a unique case of ischemic stroke caused by SAS and present a literature review on cases of SAS-associated ischemic stroke published in the past decade. The reporting of this study conforms to the CARE guidelines.

[Dynamic functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Dinamicheskaya funktsional'naya otsenka patologicheskikh izvitostei vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom. Klinicheskii sluchai.

A personalized approach with attention to anamnesis and specific symptoms is necessary in patients with internal carotid artery tortuosity. Neuroimaging (especially before elective surgery) or functional stress tests following ultrasound of supra-aortic vessels may be necessary depending on medical history and complaints. In addition to standard Doppler ultrasound, these patients should undergo rotational and orthostatic transformation tests. We analyze changes in shape and hemodynamic parameters within the tortuosity area in various body positions. This is especially valuable for patients with concomitant carotid artery stenosis. The article presents a clinical case illustrating the importance of such approach.

[Internal Carotid Artery:Development and Anomalies].

This chapter outlines the cerebrovascular developmental anatomy with emphasis on the internal carotid artery(ICA), which is important for optimal endovascular treatment of cerebrovascular system disorders. Gene expression, neural crest cells, and pharyngeal arches play key roles in the embryonic development of the carotid arteries. Evolutionary inheritance in vertebrates contributes to the formation, regression, and segmental structure of these arteries. We present examples of current mutations with regard to their segmental nature; ICA mutations are discussed primarily with regard to their developmental origin from the first to third pharyngeal arches and the role of the ductus caroticus. This comprehensive review highlights the importance of understanding the developmental and anatomical nuances of the ICA to aid with accurate diagnosis and management of vascular anomalies in the clinical setting. We have focused on the complexity associated with ICA mutations, particularly those associated with the third pharyngeal arch and the need for a solid foundation of developmental and anatomical knowledge to accurately identify and interpret their significance in the adult phenotype.

Distal normal vessel diameter might be associated with silent brain infarcts after stenting for symptomatic carotid stenosis.

BACKGROUND: Carotid artery stenting (CAS) has been the standard treatment for carotid stenosis because it is less invasive; however, the risk of periprocedural thromboembolism is high. We investigated the predictors for silent brain infarcts (SBIs), focusing on embolic protection in CAS. METHODS: This study was single-center retrospective study, and we obtained baseline demographics and clinical, laboratory, and periprocedural variables of patients who underwent CAS. Also, methods used for embolic protection (no EPD, distal EPD, or proximal balloon guiding catheter) during CAS were obtained. Distal normal vessel diameter was defined as the diameter of cervical internal carotid artery where the artery wall becomes parallel. Diffusion-weighted imaging was performed before and after procedure to detect SBIs. The primary outcome was stented territory SBIs, and the secondary outcomes were any territories SBIs and stented territory SBIs in cases with EPD. RESULTS: A total of 196 CAS procedures with mean age 69.1 ± 9.9 years were included. After CAS, stented territory SBIs occurred in 53 (27.0 %) cases and any territories SBIs in 60 (30.6 %) cases. Univariable analyses revealed that distal normal vessel diameter (odds ratio = 1.71, 95 % confidence interval = 1.20-2.43, P = 0.003) was associated with the occurrence of stented territory SBIs after CAS. After adjusting for potential variables, larger distal normal vessel diameter (1.61 [1.10-2.36], P = 0.014) increased the occurrence of SBIs after CAS. Consistent results were obtained when the outcome was any territories SBIs or stented territory SBIs in cases with EPD. CONCLUSIONS: Distal normal vessel diameter was a predictor for the occurrence of SBI after CAS. The passable pore size of EPDs may vary depending on vessel diameter, and may impact the occurrence of SBIs.

[Functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Vazhnost' dinamicheskoi funktsional'noi otsenki patologicheskoi izvitosti vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom.

The review is devoted to diagnosis and treatment of internal carotid artery tortuosity. The authors consider modern classification, epidemiology and diagnostic options using neuroimaging or ultrasound-assisted functional stress tests depending on medical history and complaints. In addition to standard Doppler ultrasound, rotational and orthostatic tests are advisable due to possible changes of local shape and hemodynamic parameters following body position changes, especially in patients with concomitant atherosclerotic stenosis. Thus, a personalized approach is especially important for treatment and diagnostics of internal carotid artery tortuosity.

Internal carotid artery bulb width: a novel potential parameter for the prediction of cerebral vascular diseases.

OBJECTIVE: To investigate the relationship between the width of the internal carotid artery (ICA) bulb and cerebral vascular diseases including stroke and intracranial aneurysms. MATERIAL AND METHODS: In total 300 patients who had supra-aortic computed tomography angiography (CTA) were enrolled in this study from 2015 to 2021. The study groups consisted of 100 ischemic stroke patients, 100 patients with intracranial aneurysms, and 100 control subjects. The intracranial aneurysm patient group was divided into two subgroups according to the presence of subarachnoid hemorrhage (SAH). The largest diameters of the ICA C1 (cervical) and C2 (petrous) segments in all individuals were measured bilaterally on CTA images. The ICA diameter ratios of the cases were measured using the formula C1-C2C1. The relationship between the age and ICA vessel analysis was evaluated as well. RESULTS: The mean ICA bulb width values in the ischemic stroke patient group and the intracranial aneurysm patient group were significantly higher than the control group (p < 0.001). The ICA C1 and C2 segment diameter values and ICA diameter ratio were smaller in the intracranial aneurysm patients with SAH than those who had not (p = 0.7). There was a statistically significant but weak relationship between the age and ICA diameter ratios in all study groups (R-squared value of 0.26, p = 0.03). CONCLUSION: ICA bulb width is a parameter that can be easily evaluated with neuroimaging modalities and is a successful method that may be used for predicting the risk of ischemic stroke or the presence of an intracranial aneurysm.

Synchronous subarachnoid haemorrhage and ischaemic stroke as a result of complete internal carotid artery occlusion.

A previously healthy man in his 60s presents with a one-day history of insidious onset headache and 'walking into doors'. He reported transient right arm pain and tingling but no weakness. A CT brain showed a right middle cerebral artery (MCA) infarct as well as a synchronous right frontal lobe convexal subarachnoid haemorrhage (cSAH). An arch to vertex CT angiogram demonstrated right MCA occlusion and complete right internal carotid artery (ICA) occlusion from its origin. Reconstitution of flow was seen within the distal right ICA at the level of the distal foramen lacerum. A repeat CT of the brain after one week showed a stable appearance of the bleeding and infarct. He was commenced on antiplatelet therapy for the treatment of the ischaemic stroke as well as secondary prevention.This is a rare case of synchronous right MCA infarct as well as a right frontal cSAH secondary to ipsilateral carotid artery occlusion.

Beware of epistaxis: fatal pseudoaneurysm rupture 30 years after treatment of acromegaly.

We present a fatal complication of treatment in a patient with early-onset acromegaly, treated with two transsphenoidal operations, radiotherapy, radiosurgery and pegvisomant. He was diagnosed in his 30s, and controlled from his 40s, with stable residual tumour within the left cavernous sinus. In his 60s, 30 years after surgery/radiotherapy and 14 years after radiosurgery, he developed recurrent episodes of mild epistaxis. A week later, he presented at his local hospital's emergency department with severe epistaxis and altered consciousness. He was diagnosed with a ruptured internal carotid artery (ICA) pseudoaneurysm, but unfortunately died before treatment could be attempted.ICA pseudoaneurysms are rare complications of surgery or radiotherapy and can present with several years of delay, often with epistaxis. This case highlights the importance of life-long monitoring in patients with previous pituitary interventions and early recognition of epistaxis as a herald sign of a potentially catastrophic event, thus leading to timely treatment.