The Role of Arterioles and the Microcirculation in the Development of Vasospasm after Aneurysmal SAH

Abstract

Cerebral vasospasm of the major cerebral arteries, which is characterized by angiographic narrowing of those vessels, had been recognized as a main contributor to delayed cerebral ischemia (DCI) in subarachnoid hemorrhage (SAH) patients. However, the CONSCIOUS-1 trial revealed that clazosentan could not improve mortality or clinical outcome in spite of successful reduction of relative risk in angiographic vasospasm. This result indicates that the pathophysiology underlying DCI is multifactorial and that other pathophysiological factors, which are independent of angiographic vasospasm, can contribute to the outcome. Recent studies have focused on microcirculatory disturbance, such as microthrombosis and arteriolar constriction, as a factor affecting cerebral ischemia after SAH. Reports detecting microthrombosis and arteriolar constriction will be reviewed, and the role of the microcirculation on cerebral ischemia during vasospasm after SAH will be discussed.

The Human Microcirculation

“…Microcirculatory dysfunction contributes etiologically or has a primary association with a myriad of diseases including obstructive sleep apnea 32 , hypertrophic cardiomyopathy 10 , stress-related cardiomyopathy 33 , congestive heart failure with reduced ejection fraction 34 , idiopathic cardiomyopathy 35 , heart failure with preserved ejection fraction 36, 37 , inflammatory bowel disease 38, 39 , schizophrenia 40 , amyloidosis 41 , tobacco use 42 , aging 43 , systemic lupus erythematosus 44 , and even a sedentary life style 45 . Abnormalities in the microcirculation are responsible for no-reflow phenomenon (reviewed by Feher et al 46 ), damage from cardioplegic arrest 47 , coronary microvascular spasm 48 , cerebral vasospasm following subarachnoid hemorrhage 49 , and angiogenesis 50, 51 , including tumor angiogenesis 52 . To the extent that these associations are confirmed as causal, the implications for treatment and prevention will be substantial.…”

F2-isoprostanes and F4-neuroprostanes as markers of intracranial aneurysm development

“…In our observation, the advancement of hemorrhagic and edemic changes observed in the brain in the course of SAH did not correlate with the parameters of oxidative stress in the blood, which has been observed in CSF. 37 The neurosurgical treatment of SAH patients diagnosed with a ruptured aneurysm consists of clipping or coiling as less invasive techniques. Aneurysm embolization was performed in 19 patients, which accounted for 58% of patients.…”

Clinical Prognosis for SAH Consistent with Redox Imbalance and Lipid Peroxidation

“…Each SAH-patient during an admission was assessed with the World Federation of Neurological Surgeons Scale (WFNS), the Hunt-Hess scale (H-H), and the Fisher Scale [48,49]. During hospitalization in the course of SAH the vasospasm was monitored with transcranial Doppler (TCD) [50]. The study material was taken from patients after 1 day and then 6 to 8 days after SAH to compare changes in the body over time.…”