scholarly journals Cerebral microcirculatory failure after subarachnoid hemorrhage is reversed by hyaluronidase

2016 ◽  
Vol 36 (9) ◽  
pp. 1537-1552 ◽  
Author(s):  
Evan D McConnell ◽  
Helen S Wei ◽  
Katherine M Reitz ◽  
Hongyi Kang ◽  
Takahiro Takano ◽  
...  

Aneurysmal subarachnoid hemorrhage remains one of the more devastating forms of stroke due in large part to delayed cerebral ischemia that appears days to weeks following the initial hemorrhage. Therapies exclusively targeting large caliber arterial vasospasm have fallen short, and thus we asked whether capillary dysfunction contributes to delayed cerebral ischemia after subarachnoid hemorrhage. Using a mouse model of subarachnoid hemorrhage and two-photon microscopy we showed capillary dysfunction unrelated to upstream arterial constriction. Subarachnoid hemorrhage decreased RBC velocity by 30%, decreased capillary pulsatility by 50%, and increased length of non-perfusing capillaries by 15%. This was accompanied by severe brain hypoxia and neuronal loss. Hyaluronidase, an enzyme that alters capillary blood flow by removing the luminal glycocalyx, returned RBC velocity and pulsatility to normal. Hyaluronidase also reversed brain hypoxia and prevented neuron loss typically seen after subarachnoid hemorrhage. Thus, subarachnoid hemorrhage causes specific changes in capillary RBC flow independent of arterial spasm, and hyaluronidase treatment that normalizes capillary blood flow can prevent brain hypoxia and injury after subarachnoid hemorrhage. Prevention or treatment of capillary dysfunction after subarachnoid hemorrhage may reduce the incidence or severity of subarachnoid hemorrhage-induced delayed cerebral ischemia.

Neurosurgery ◽  
1990 ◽  
Vol 27 (5) ◽  
pp. 729-740 ◽  
Author(s):  
Thomas C. Origitano ◽  
Thomas M. Wascher ◽  
Howard O. Reichman ◽  
Douglas E. Anderson

Abstract Delayed cerebral ischemia is the major cause of death and disability in patients who initially survive an aneurysmal subarachnoid hemorrhage (SAH). In the present study, a protocol for prophylactic hypertensive hypervolemic hemodilution (“triple-H” therapy) was utilized in the treatment of SAH, and the response of cerebral blood flow (CBF) was evaluated. Serial CBF measurements, f1 and CBF15, were performed using the xenon-133 inhalation technique to maximize therapy. Surgery within 24 hours of subarachnoid hemorrhage was preferred. In 43 patients with SAH, mean hemoglobin and hematocrit were lowered 3.0 ± 0.3 g/dL and 8.9 ± 0.5%, respectively, over the first 24 hours. Mean f1 and mean CBF15 over the same period increased 34.2 ± 5.8% and 21.2 ± 3.6%, respectively. The maximum mean increase in CBF was 47.2 ± 4.7% for f1 and 30.1 ± 3.2% for CBF15. Cerebral blood flow remained elevated during the 21 days after SAH, irrespective of neurological grade on admission, age, sex, or angiographic arterial narrowing. This is the first report of a consistent method for establishing sustained improvement in CBF after SAH. All patients managed in total compliance with the protocol remained neurologically stable or improved. Two patients developed delayed ischemia and infarction because of the inability to sustain protocol requirements. Thirty-six of the 43 patients (84%) were discharged capable of an independent lifestyle. Triple-H therapy is a safe and effective modality for elevating and sustaining CBF after SAH. In combination with early aneurysm surgery, it can minimize delayed cerebral ischemia and lead to an improved overall outcome.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vasilios E. Papaioannou ◽  
Karol P. Budohoski ◽  
Michal M. Placek ◽  
Zofia Czosnyka ◽  
Peter Smielewski ◽  
...  

Abstract Background Cerebral vasospasm (VS) and delayed cerebral ischemia (DCI) constitute major complications following subarachnoid hemorrhage (SAH). A few studies have examined the relationship between different indices of cerebrovascular dynamics with the occurrence of VS. However, their potential association with the development of DCI remains elusive. In this study, we investigated the pattern of changes of different transcranial Doppler (TCD)-derived indices of cerebrovascular dynamics during vasospasm in patients suffering from subarachnoid hemorrhage, dichotomized by the presence of delayed cerebral ischemia. Methods A retrospective analysis was performed using recordings from 32 SAH patients, diagnosed with VS. Patients were divided in two groups, depending on development of DCI. Magnitude of slow waves (SWs) of cerebral blood flow velocity (CBFV) was measured. Cerebral autoregulation was estimated using the moving correlation coefficient Mxa. Cerebral arterial time constant (tau) was expressed as the product of resistance and compliance. Complexity of CBFV was estimated through measurement of sample entropy (SampEn). Results In the whole population (N = 32), magnitude of SWs of ipsilateral to VS side CBFV was higher during vasospasm (4.15 ± 1.55 vs before: 2.86 ± 1.21 cm/s, p < 0.001). Ipsilateral SWs of CBFV before VS had higher magnitude in DCI group (N = 19, p < 0.001) and were strongly predictive of DCI, with area under the curve (AUC) = 0.745 (p = 0.02). Vasospasm caused a non-significant shortening of ipsilateral values of tau and increase in SampEn in all patients related to pre-VS measurements, as well as an insignificant increase of Mxa in DCI related to non-DCI group (N = 13). Conclusions In patients suffering from subarachnoid hemorrhage, TCD-detected VS was associated with higher ipsilateral CBFV SWs, related to pre-VS measurements. Higher CBFV SWs before VS were significantly predictive of delayed cerebral ischemia.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 820
Author(s):  
Keshav Jayaraman ◽  
Meizi Liu ◽  
Gregory J. Zipfel ◽  
Umeshkumar Athiraman

Numerous studies have demonstrated the ability of isoflurane conditioning to provide multifaceted protection against aneurysmal subarachnoid hemorrhage (SAH)-associated delayed cerebral ischemia (DCI); however, preclinical studies have not yet examined whether other commonly used inhalational anesthetics in neurological patients such as sevoflurane or desflurane are also protective against SAH-induced neurovascular deficits. We therefore sought to identify the potential for sevoflurane and desflurane conditioning to protect against DCI in an endovascular perforation mouse model of SAH. Neurological function was assessed daily via neuroscore. Large artery vasospasm and microvessel thrombosis were assessed three days after SAH or sham surgery. Four groups were examined: Sham, SAH + room air, SAH + 2% Sevoflurane, and SAH + 6% Desflurane. For the SAH groups, one hour after surgery, mice received 2% sevoflurane, 6% desflurane, or room air for one hour. We found that conditioning with sevoflurane or desflurane attenuated large artery vasospasm, reduced microvessel thrombosis, and improved neurologic function. Given their frequent clinical use and strong safety profile in patients (including those with SAH), these data strongly support further studies to validate these findings in preclinical and clinical studies and to elucidate the mechanisms by which these agents might be acting.


Author(s):  
Claudia Ditz ◽  
Björn Machner ◽  
Hannes Schacht ◽  
Alexander Neumann ◽  
Peter Schramm ◽  
...  

AbstractPlatelet activation has been postulated to be involved in the pathogenesis of delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to investigate potentially beneficial effects of antiplatelet therapy (APT) on angiographic CVS, DCI-related infarction and functional outcome in endovascularly treated aSAH patients. Retrospective single-center analysis of aSAH patients treated by endovascular aneurysm obliteration. Based on the post-interventional medical regime, patients were assigned to either an APT group or a control group not receiving APT. A subgroup analysis separately investigated those APT patients with aspirin monotherapy (MAPT) and those receiving dual treatment (aspirin plus clopidogrel, DAPT). Clinical and radiological characteristics were compared between groups. Possible predictors for angiographic CVS, DCI-related infarction, and an unfavorable functional outcome (modified Rankin scale ≥ 3) were analyzed. Of 160 patients, 85 (53%) had received APT (n = 29 MAPT, n = 56 DAPT). APT was independently associated with a lower incidence of an unfavorable functional outcome (OR 0.40 [0.19–0.87], P = 0.021) after 3 months. APT did not reduce the incidence of angiographic CVS or DCI-related infarction. The pattern of angiographic CVS or DCI-related infarction as well as the rate of intracranial hemorrhage did not differ between groups. However, the lesion volume of DCI-related infarctions was significantly reduced in the DAPT subgroup (P = 0.011). Post-interventional APT in endovascularly treated aSAH patients is associated with better functional outcome at 3 months. The beneficial effect of APT might be mediated by reduction of the size of DCI-related infarctions.


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