Prophylactic intra-arterial injection of vasodilator for asymptomatic vasospasm converts the patient to symptomatic vasospasm due to severe microcirculatory imbalance

Vasospasm-Related Death after Aneurysmal Subarachnoid Hemorrhage: A Retrospective Case–Control Study

Background: Vasospasm after the rupture of an intracranial aneurysm is a frequent phenomenon and is the main cause of morbidity and mortality in patients who have survived intracranial hemorrhage and aneurysm treatment. We analyzed the diagnosis and management of patients with aneurysmal subarachnoid hemorrhage who eventually died from ischemic brain damage due to vasospasm. Methods: Between January 2007 and December 2021 (15 years), a total of 1064 patients were diagnosed with an aneurysmal intracranial hemorrhage in a single comprehensive neurovascular center. Vasospasm was diagnosed in 408 patients (38.4%). A total of 187 patients (17.6%) died within 90 days of the aneurysm rupture. In 64 of these 187 patients (33.7%), vasospasm was considered to be the cause of death. In a retrospective analysis, demographic and clinical data for patients without, with non-fatal, and with fatal vasospasm were compared. The patients with fatal vasospasm were categorized into the following subgroups: “no diagnosis and treatment” (Group a), “delayed diagnosis” (Group b), “cardiovascular complications” (Group c), and “vasospasm-treatment complications” (Group d). Results: Among the patients with fatal vasospasm, 31 (48.4%) were assigned to group a, 26 (40.6%) to group b, seven (10.9%) to group c, and none (0%) to group d. Conclusion: The early recognition of severe posthemorrhagic vasospasm is a prerequisite for any treatment and requires routine diagnostic imaging in all unconscious patients. Aggressive endovascular vasospasm treatment may fail to prevent death but is infrequently the cause of a fatal outcome.

Ruptured AComA aneurysm and asymptomatic bilateral ACA vasospasm in an infant: surgical case report

Intracranial aneurysms (IAs) are localized dilations of the cerebral vasculature, representing the leading cause for non-traumatic subarachnoid hemorrhage and an important source of morbidity and mortality. Despite it being a frequent pathology and most often diagnosed incidentally, IAs in infants are a very rare occurrence, and the ruptured variant is exceptional. A 4-month-old boy with a negative family history was brought to our department because of several episodes of incoercible vomiting and fever. Upon examination, the child was somnolent, without any noticeable deficit. Transfontanellar ultrasonography and CT angiography revealed a ruptured aneurysm of the anterior communicating artery (AComA), whereas the pre-clipping MRI showed thin, almost angiographically invisible anterior cerebral arteries (ACAs) on both sides due to vasospasm. We intervened surgically by placing an external ventricular shunt in an emergency setting, followed by clipping of the IA in a delayed manner. The child was discharged a month after admission with no deficit, despite the paradoxical aspect of the ACA. Ruptured IAs can be safely treated via microsurgery, even in infants. However, this requires a great amount of experience and surgical expertise. Furthermore, the lack of proper management would most likely result in a severe deficit in the long term. Lastly, the lack of visibility of the ACA on angiographic studies may not have neurological consequences if they occur in this age group.

The Effects of Cerebral Vasospasm on Cerebral Blood Flow and the Effects of Induced Hypertension: A Mathematical Modelling Study

Background

Induced hypertension has been used to promote cerebral blood flow under vasospastic conditions although there is no randomised clinical trial to support its use. We sought to mathematically model the effects of vasospasm on the cerebral blood flow and the effects of induced hypertension.

Methods

The Anatomically Detailed Arterial Network (ADAN) model is employed as the anatomical substrate in which the cerebral blood flow is simulated as part of the simulation of the whole body arterial circulation. The pressure drop across the spastic vessel is modelled by inserting a specific constriction model within the corresponding vessel in the ADAN model. We altered the degree of vasospasm, the length of the vasospastic segment, the location of the vasospasm, the pressure (baseline mean arterial pressure [MAP] 90 mm Hg, hypertension MAP 120 mm Hg, hypotension), and the presence of collateral supply.

Results

Larger decreases in cerebral flow were seen for diffuse spasm and more severe vasospasm. The presence of collateral supply could maintain cerebral blood flow, but only if the vasospasm did not occur distal to the collateral. Induced hypertension caused an increase in blood flow in all scenarios, but did not normalise blood flow even in the presence of moderate vasospasm (30%). Hypertension in the presence of a complete circle of Willis had a marginally greater effect on the blood flow, but did not normalise flow.

Conclusion

Under vasospastic condition, cerebral blood flow varies considerably. Hypertension can raise the blood flow, but it is unable to restore cerebral blood flow to baseline.

Atorvastatin Protects Against Cerebral Aneurysmal Degenerative Pathology by Promoting Endothelial Progenitor Cells (EPC) Mobilization and Attenuating Vascular Deterioration in a Rat Model

Background

Endothelial injury is the early pathological change of cerebral aneurysm (CA) formation. In addition to its lipid-lowering activity, atorvastatin (ATR) also reportedly promotes vascular repair via mobilizing endothelial progenitor cells (EPC). Here, we investigated the influence of ATR on vascular worsening after CA induction in rats.

Material/Methods

Adult male Sprague-Dawley rats were randomly assigned to 3 groups: a control (CTR) group, a CA group, and a CA+ATR treatment group. Circulating EPC level and hematological and lipid profiles were measured 3 months after CA induction. Verhoeff-Van Gieson staining and transmission electron microscopy were performed to assess pathological changes in the artery wall. RT-PCR was also performed to evaluate the expression of inflammation-related genes in the aneurysmal wall.

Results

ATR significantly restored the impaired level of circulating EPC without changing hematological and lipid profiles 3 months after CA induction. ATR markedly inhibited endothelial injury, media thinning, and CA enlargement, accompanied by reduced vascular inflammation.

Conclusions

Our preliminary results demonstrate that the mobilization of EPC and improvement of endothelial function by ATR contribute to the prevention of cerebral aneurysm. Further studies are warranted to investigate the detailed mechanism.