Causes of morbidity and mortality following intracranial aneurysm rupture

Coil migration through two flow-diverting stents

We report a case of a patient who initially presented with a subarachnoid haemorrhage secondary to a ruptured supraclinoid internal carotid artery (ICA) blister aneurysm. The patient was treated successfully with a flow diverter stent (FD) and coiling; however, a large aneurysm recurrence via a feeding posterior communicating artery (PCOM) was noted on the 1-year follow-up angiogram. During the retreatment, a second FD in the ICA resulted in insufficient aneurysm stasis. Therefore, the decision was made to coil sacrifice the PCOM via posterior circulation access. During the first coil deployment, the distal coil end migrated through the mesh of two overlapping FD into the middle cerebral artery. This complication was a previously unrecognised possibility given the composition of the FD. This case report aims to discuss this process as a potential complication during neurointerventional procedures using these devices.

Impact of spatial and temporal stability of flow vortices on vascular endothelial cells

PURPOSE

Intracranial aneurysms (IAs) are pathological dilations of cerebrovascular vessels due to degeneration of the mechanical strength of the arterial wall, precluded by altered cellular functionality. The presence of swirling hemodynamic flow (vortices) is known to alter vascular endothelial cell (EC) morphology and protein expression indicative of IAs. Unfortunately, less is known if vortices with varied spatial and temporal stability lead to differing levels of EC change. The aim of this work is to investigate vortices of varying spatial and temporal stability impact on ECs.

METHODS

Vortex and EC interplay was investigated by a novel combination of parallel plate flow chamber (PPFC) design and computational analysis. ECs were exposed to laminar (7.5 dynes/[Formula: see text] wall shear stress) or low (<1 dynes/[Formula: see text]) stress vortical flow using PPFCs. Immunofluorescent imaging analyzed EC morphology, while ELISA tests quantified VE-cadherin (cell-cell adhesion), VCAM-1 (macrophage-EC adhesion), and cleaved caspase-3 (apoptotic signal) expression. PPFC flow was simulated, and vortex stability was calculated via the temporally averaged degree of (volume) overlap (TA-DVO) of vortices within a given area.

RESULTS

EC morphological changes were independent of vortex stability. Increased stability promoted VE-cadherin degradation (correlation coefficient r = [Formula: see text]0.84) and 5-fold increased cleaved caspase-3 post 24 h in stable (TA-DVO 0.736 ± 0.05) vs unstable (TA-DVO 0.606 [Formula: see text]0.2) vortices. ECs in stable vortices displayed a 4.5-fold VCAM-1 increase than unstable counterparts after 12 h.

CONCLUSION

This work demonstrates highly stable disturbed flow imparts increased inflammatory signaling, degraded cell-cell adhesion, and increased cellular apoptosis than unstable vortices. Such knowledge offers novel insight toward understanding IA development and rupture.

Optimal Cost-Effective Screening Strategy for Unruptured Intracranial Aneurysms in Female Smokers

BACKGROUND

The prevalence of intracranial aneurysms among female cigarette smokers was shown to be high in previous studies, yet the cost-effectiveness of screening them has never been explored.

OBJECTIVE

To explore the most cost-effective screening strategy for female smokers.

METHODS

A decision analytical study was performed with a Markov model to compare different screening strategies with no screening and to explore the most optimal screening strategy for female smokers. Input data for the model were extracted from literature. A single screening at different ages and multiple screening every 15 years, 10 years, 5 years, and 2 years were performed for female smokers in different age ranges. Deterministic and probabilistic sensitivity analyses were performed to evaluate the robustness of the model. Finally, value of information analysis was performed to investigate the value of collecting additional data.

RESULTS

Screening female smokers for unruptured intracranial aneurysm is cost-effective. All screening strategies yield extra quality-adjusted life years. Screening at younger age brings more health benefit at lower cost. Frequent screening strategies decrease rupture rate of aneurysms more with higher costs per quality-adjusted life year. Screening after age 70 years and frequent screening (every 2 years) after age 60 years is not optimal. Among all the parameters in the model, collecting additional data on utility of the unscreened population would be most valuable.

CONCLUSION

Screening female smokers for intracranial aneurysms once at younger age is most optimal. However, in clinical practice, the duration and intensity of exposure to cigarettes should be taken into consideration.

Cost-effectiveness analysis on small (< 5 mm) unruptured intracranial aneurysm follow-up strategies

OBJECTIVE

Unruptured intracranial aneurysms are frequently detected during routine clinical diagnostic processes. A significant portion are small aneurysms less than 5 mm in diameter. While follow-up of patients with small aneurysms has been advocated, the cost-effectiveness of such care and the optimal follow-up interval remain unknown. This study aimed to explore the most cost-effective follow-up interval for small (< 5 mm) unruptured intracranial aneurysms.

METHODS

A decision analysis study was performed using a Markov model with Monte Carlo simulations to simulate patients undergoing follow-up by MRA at different time intervals (1-, 2-, 3-, 5-, and 7-year intervals) for small (< 5 mm) unruptured intracranial aneurysms. Input data for the model were extracted from the current literature, primarily meta-analyses. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model.

RESULTS

Given the current literature and the model in this study, following up every 2 years with noninvasive imaging is the most cost-effective strategy (cost $126,996, effectiveness 21.9 quality-adjusted life-years), showing the highest net monetary benefit. The conclusion remains robust in probabilistic and deterministic sensitivity analyses. As the annual growth risk of small aneurysms and annual rupture risk of growing aneurysms increase, following up every year is optimal. When the cost for follow-up with MRA is less than $2223, following up every year is cost-effective.

CONCLUSIONS

The most cost-effective follow-up strategy for small (< 5 mm) unruptured aneurysms using MRA is following up every 2 years. More frequent follow-up strategies or prompt preventive treatment would be more appropriate in patients with higher risk factors for growth and aneurysm rupture.

Avenir® vs. AxiumTM Coils for the Treatment of Intracranial Aneurysms: Results of a Multicenter Randomized Controlled Trial With Short-Term Follow-Up

Purpose

Endovascular coil occlusion is a successful and rapidly evolving strategy used to treat patients who present with intracranial aneurysms. This study aimed to compare the safety and efficacy of the Avenir® and Axium^TM passive mechanically detachable coil systems.

Methods

A prospective, multicenter, randomized controlled study was carried out at ten medical centers from March 2018 to December 2019. A series of consecutive patients diagnosed with intracranial aneurysms were randomly assigned to undergo endovascular treatment with either the Avenir® or the Axium^TM mechanically detachable coil systems. The short-term outcomes from the two groups were compared with a focus on treatment efficacy and safety.

Results

A total of 162 and 161 patients were enrolled in the Avenir and Axium groups, respectively. The rate of successful coil detachment was 100% for the Avenir group and 99.38% for the Axium group. At the six-month follow-up visit, the overall aneurysm occlusion rate was 94.66% for the Avenir group and 96.95% for the Axium group (p > 0.05). We observed no statistically significant differences in clinical condition (as per the modified Rankin Scale) or the degree of aneurysm occlusion (as determined by digital subtraction angiography [DSA] and Raymond-Roy Occlusion Classification). Surgical complications were reported in 27 subjects in the Avenir group and 22 in the Axium group (p > 0.05). DSA performed at 6 months revealed complete aneurysm occlusion in 84 and 86% of patients in the Avenir and Axium groups, respectively.

Conclusion

We observed no significant short-term differences with respect to efficacy or safety when using either Avenir® or Axium^TM coils for the treatment of intracranial aneurysms.

Aberrant Whole Blood Gene Expression in the Lumen of Human Intracranial Aneurysms

The rupture of an intracranial aneurysm (IA) causes devastating hemorrhagic strokes. Yet, most IAs remain asymptomatic and undetected until they rupture. In the search for circulating biomarkers of unruptured IAs, we previously performed transcriptome profiling on whole blood and identified an IA-associated panel of 18 genes. In this study, we seek to determine if these genes are also differentially expressed within the IA lumen, which could provide a mechanistic link between the disease and the observed circulating gene expression patterns. To this end, we collected blood from the lumen of 37 IAs and their proximal parent vessels in 31 patients. The expression levels of 18 genes in the lumen and proximal vessel were then measured by quantitative polymerase chain reaction. This analysis revealed that the expression of 6/18 genes (CBWD6, MT2A, MZT2B, PIM3, SLC37A3, and TNFRSF4) was significantly higher in intraluminal blood, while the expression of 3/18 genes (ST6GALNAC1, TCN2, and UFSP1) was significantly lower. There was a significant, positive correlation between intraluminal and proximal expression of CXCL10, MT2A, and MZT2B, suggesting local increases of these genes is reflected in the periphery. Expression of ST6GALNAC1 and TIFAB was significantly positively correlated with IA size, while expression of CCDC85B was significantly positively correlated with IA enhancement on post-contrast MRI, a metric of IA instability and risk. In conclusion, intraluminal expression differences in half of the IA-associated genes observed in this study provide evidence for IA tissue-mediated transcriptional changes in whole blood. Additionally, some genes may be informative in assessing IA risk, as their intraluminal expression was correlated to IA size and aneurysmal wall enhancement.

Comorbidities and Medical Complications in Hospitalized Subarachnoid Hemorrhage Patients

BACKGROUND

Aneurysmal subarachnoid hemorrhage (SAH) remains a devastating condition with a case fatality of 36% at 30 days. Risk factors for mortality in SAH patients include patient demographics and the severity of the neurological injury. Pre-existing conditions and non-neurological medical complications occurring during the index hospitalization are also risk factors for mortality in SAH. The magnitude of the effect on mortality of pre-existing conditions and medical complications, however, is less well understood. In this study, we aim to determine the effect of pre-existing conditions and medical complications on SAH mortality.

METHODS

For a 25% random sample of the Greater Montreal Region, we used discharge abstracts, physician billings, and death certificate records, to identify adult patients with a new diagnosis of non-traumatic SAH who underwent cerebral angiography or surgical clipping of an aneurysm between 1997 and 2014.

RESULTS

The one-year mortality rate was 14.76% (94/637). Having ≥3 pre-existing conditions was associated with increased one-year mortality OR 3.74, 95% CI [1.25, 9.57]. Having 2, or ≥3 medical complications was associated with increased one-year mortality OR, 2.42 [95% CI 1.25-4.69] and OR, 2.69 [95% CI 1.43-5.07], respectively. Sepsis, respiratory failure, and cardiac arrhythmias were associated with increased one-year mortality. Having 1, 2, or ≥3 pre-existing conditions was associated with increased odds of having medical complications in hospital.

CONCLUSIONS

Pre-existing conditions and in-hospital non-neurological medical complications are associated with increased one-year mortality in SAH. Pre-existing conditions are associated with increased medical complications.

Surgical Versus Endovascular Management of Ruptured and Unruptured Intracranial Aneurysms: Emergent Issues and Future Directions

Ideal management of unruptured intracranial aneurysms (UIAs) and ruptured intracranial aneurysms (RIAs) is a controversial issue. Over the last few decades, a significant paradigm shift has occurred away from open microsurgical clipping toward endovascular coil embolization. Multiple studies have been performed with mixed results. Some studies suggest that endovascular treatment produces better clinical and functional outcomes, but is associated with increased need for retreatment. Other studies report increased durability in aneurysms treated with microsurgical clipping, but that clipping may be associated with worse functional outcomes in some cases. Further complicating the dialogue are variable costs associated with different treatment modalities, including country-dependent cost differences. Here we provide a review of some of the major studies comparing open surgery versus endovascular treatment for both RIAs and UIAs to distill their key findings and corresponding implications for clinical practice. We relate these research results to our institution's experience with RIAs and UIAs and describe our approach to treatment of these conditions. Finally, we discuss implications of the paradigm shift for both open and endovascular surgery, including educational initiatives directed toward preserving important microsurgical tenets in the setting of diminishing surgical volume.

Clinical evidence of efficacy of simvastatin for aneurysmal subarachnoid hemorrhage

Objective

The present study was performed to explore the therapeutic potential of simvastatin in subarachnoid hemorrhage (SAH) in the context of the Simvastatin in Aneurysmal Subarachnoid Hemorrhage (STASH) trial.

Methods

MEDLINE, EMBASE, and the Cochrane Library were searched for all randomized controlled trials (RCTs) investigating the therapeutic effect of simvastatin on aneurysmal SAH. We applied a random-effects model to calculate the data.

Results

Five RCTs involving 951 patients met the eligibility criteria. We found no statistically significant effects on vasospasm detected by transcranial cerebral Doppler (relative risk [RR], 0.91; 95% confidence interval [CI], 0.55–1.49), delayed cerebral ischemia (DCI) (RR, 0.85; 95% CI, 0.63–1.14), or all-cause mortality (RR, 1.02; 95% CI, 0.67–1.54). Subgroup analysis showed that these consolidated results were stable at different doses, different times to start of treatment, and different courses of treatment in all included RCTs. Sensitivity analysis showed that the STASH trial, which had a large population, did not influence the consolidated results of all three outcomes.

Conclusions

Simvastatin showed no benefits in decreasing the incidence of vasospasm, DCI, or all-cause mortality after aneurysmal SAH. We conclude that patients with SAH should not be treated routinely with simvastatin during the acute stage.

Aneurysmal Surgery in the Presence of Angiographic Vasospasm: An Outcome Assessment

Background and Purpose:

The timing of aneurysmal surgery for patients presenting within the period at risk for vasospasm (VS) is controversial. The goal of this study is to review our experience of surgically treated patients in the presence of angiographic VS.

Materials and Methods:

From 1990-2004, 894 consecutive patients presented with an aneurysmal subarachnoid hemorrhage (SAH) and were treated with a policy of early surgery. We retrospectively analyzed the patients that had pre-operative angiographic VS. In this study, symptomatic VS was diagnosed when a decreased level of consciousness and/or focal deficit occurred after SAH in the presence of angiographic VS without confounding factors. Functional outcome was assessed three months after SAH using the Glasgow Outcome Scale.

Results:

Of the 40 patients studied, 62.5% were in good clinical grade Hunt & Hess (H&H 1-2) on admission; 25%, intermediate grade (H&H 3); 12.5%, poor grade (H&H 4-5). Surgery was performed 24 hours or less after initial angiography in 87.5% of patients and less than 48 hours in 97.5%. Pre-operative symptomatic VS was diagnosed in 25%. Postoperatively, angiographic VS was documented in 87.2%. Of the 30% of patients that presented post-operative symptomatic VS, 66.7% also demonstrated pre-operative symptomatic VS. The functional outcome was favorable in 92.5% of the studied patients. Two deaths occurred in patients presenting pre-operative early radiological and symptomatic VS.

Conclusion:

Aneurysmal surgery, especially between 3-12 days following SAH, in the presence of asymptomatic pre-operative angiographic VS can be associated with a good outcome. Early surgery is not contra-indicated and might enable optimal treatment of VS.

Operative complications and differences in outcome after clipping and coiling of ruptured intracranial aneurysms

OBJECT

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with substantial morbidity and mortality, with better outcomes reported following endovascular coiling compared with neurosurgical clipping of the aneurysm. The authors evaluated the contribution of perioperative complications and neurological decline to patient outcomes after both aneurysm-securing procedures.

METHODS

A post hoc analysis of perioperative complications from the Clazosentan to Overcome Neurological iSChemia and Infarction Occurring after Subarachnoid hemorrhage (CONSCIOUS-1) study was performed. Glasgow Coma Scale (GCS) scores for patients who underwent neurosurgical clipping and endovascular coiling were analyzed preoperatively and each day following the procedure. Complications associated with a decline in postoperative GCS scores were identified for both cohorts. Because patients were not randomized to the aneurysm-securing procedures, propensity-score matching was performed to balance selected covariates between the 2 cohorts. Using a multivariate logistic regression, the authors evaluated whether a perioperative decline in GCS scores was associated with long-term outcomes on the extended Glasgow Outcome Scale (eGOS).

RESULTS

Among all enrolled subjects, as well as the propensity-matched cohort, patients who underwent clipping had a significantly greater decline in their GCS scores postoperatively than patients who underwent coiling (p = 0.0024). Multivariate analysis revealed that intraoperative hypertension (p = 0.011) and intraoperative induction of hypotension (p = 0.0044) were associated with a decline in GCS scores for patients undergoing clipping. Perioperative thromboembolism was associated with postoperative GCS decline for patients undergoing coiling (p = 0.03). On multivariate logistic regression, postoperative neurological deterioration was strongly associated with a poor eGOS score at 3 months (OR 0.86, 95% CI 0.78-0.95, p = 0.0032).

CONCLUSIONS

Neurosurgical clipping following aSAH is associated with a greater perioperative decline in GCS scores than endovascular coiling, which is in turn associated with poorer long-term outcomes. These findings provide novel insight into putative mechanisms of improved outcomes following coiling, highlighting the potential importance of perioperative factors when comparing outcomes between clipping and coiling and the need to mitigate the morbidity of surgical strategies following aSAH.

Vasospasm: my first 25 years-what worked? what didn't? what next?

Angiographic vasospasm as a complication of aneurysmal and other types of subarachnoid hemorrhage (SAH) was identified about 62 years ago. It is now hypothesized that angiographic vasospasm contributes to delayed cerebral ischemia (DCI) by multiple pathways, including reduced blood flow from angiographic vasospasm as well as microcirculatory constriction, microthrombosis, cortical spreading ischemia, and delayed effects of early brain injury. It is likely that other factors, such as systemic complications, effects of the subarachnoid blood, brain collateral and anastomotic blood flow, and the genetic and epigenetic makeup of the patient, contribute to the individual's response to SAH. Treatment of aneurysmal SAH and DCI includes neurocritical care management, early aneurysm repair, prophylactic administration of nimodipine, and rescue therapies (induced hypertension and balloon or pharmacologic angioplasty) if the patient develops DCI. Well-designed clinical trials of tirilazad, clasozentan, antiplatelet drugs, and magnesium have been conducted using more than a 1,000 patients each. Some of these drugs have almost purely vascular effects; other drugs are theoretically neuroprotective as well, but they share in common the ability to reduce angiographic vasospasm and, in many cases, DCI, but have no effect on clinical outcome. Experimental research in SAH continues to identify new targets for therapy. Challenges for the future will be to identify the most promising drugs to advance from preclinical studies and to understand why clinical trials have so frequently failed to show drug benefit on clinical outcome. Similar issues with treatment of ischemic stroke are being addressed by suggestions for improving the quality of experimental studies, collaborative preclinical trials, and multinational, multicenter clinical studies that can rapidly include many patients and be large enough to account for numerous factors that conspire to disrupt clinical trials.

Cerebral Vasospasm – A serious obstacle in a successful aneurysm surgery

Background: Cerebral vasospasm that occurs after subarachnoid hemorrhage (SAH) can be an important cause of mortality and morbidity for patients successfully operated for a cerebral aneurysm.

Methods: Five cases of prompt diagnostic and surgical treatment of a cerebral aneurysm, with important SAH on cerebral computed tomography (CT) at onset, are presented. All patients were admitted in a poor neurological state and developed severe vasospasm. Both, the correct clipping of the aneurysm and the cerebral vasospasm were angiographic demonstrated in all cases. Two patients showed complete obliteration of one carotid artery.

Results: Postoperatory, four of the patients were treated with intrathecally administered nimodipine (10mg/50ml). In three cases, the procedure caused the reverse of the vasospasm and clinical improvement of the patients. Their clinical outcomes were very good and were discharged with minimal neurological deficits. In one case, repeated intraarterial administration of nimodipine, showed no reduction of the vasospasm, and no improvement of patient’s clinical status. The patient was conscious, but presented focal neurological deficits (hemiplegia and aphasia). One patient did not benefit from this treatment and had a poor clinical outcome, remaining in a vegetative state.

Conclusions: Cerebral vasoconstriction after SAH could be an important obstacle in obtaining very good results in aneurysm surgery. Intra-arterial administration of nimodipine is an important and useful treatment, but good results in reversal severe cerebral vasospasm are not always mandatory.

Imidapril inhibits cerebral aneurysm formation in an angiotensin-converting enzyme-independent and matrix metalloproteinase-9-dependent manner

BACKGROUND

Cerebral aneurysms (CAs) have a high prevalence in the general population and cause lethal subarachnoid hemorrhage. We recently demonstrated that chronic inflammation is an underlying pathogenesis of CA. However, we identified the negative involvement of angiotensin receptor signaling in the pathogenesis of CA.

OBJECTIVE

To elucidate the involvement of the renin-angiotensin system (RAS) by assessing the expression and activity of angiotensin-converting enzyme (ACE), a key enzyme of RAS, during CA formation and evaluating the effect of imidapril, an ACE inhibitor and a potent inhibitor of matrix metalloproteinase-9 (MMP-9), on CA formation.

METHODS

Surgically induced CA models of rats were used. Imidapril was given intraperitoneally to rats, and aneurysm size and medial thickness of CAs were examined 1 month after induction. Then, ACE and MMP-9 expression was assessed by immunostaining and Western blot analysis. The MMP-9 activity was evaluated by gelatin zymography, and ACE expression in human CA walls was assessed by immunostaining.

RESULTS

Imidapril significantly suppressed the size and medial thinning of induced CAs. The expression and activity of ACE were not induced in CA walls. Furthermore, imidapril treatment did not influence ACE expression and activity, suggesting that the inhibitory effect of imidapril was independent of an inhibition of the RAS. Imidapril inhibited MMP-9 activity upregulated in CA walls. In an in vitro study, imidapril suppressed MMP-9 activity in a dose-dependent manner. In human CA walls, as in the rat model, ACE expression was not upregulated.

CONCLUSION

Angiotensin-converting enzyme is not involved in the pathogenesis of CA formation. Imidapril suppresses CA formation in an ACE-independent and MMP-9-dependent manner.

A novel intravital method to evaluate cerebral vasospasm in rat models of subarachnoid hemorrhage: a study with synchrotron radiation angiography

Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood flow measurement, [¹²⁵I]N-isopropyl-p-iodoamphetamine cerebral blood flow measurement and terminal examinations were applied to evaluate the changes of anterior circulation arteries in two subarachnoid hemorrhage models made by blood injection into cisterna magna and prechiasmatic cistern. Using synchrotron radiation angiography technique, we detected cerebral vasospasm in subarachnoid hemorrhage rats compared to the controls (p<0.05). We also identified two interesting findings: 1) both middle cerebral artery and anterior cerebral artery shrunk the most at day 3 after subarachnoid hemorrhage; 2) the diameter of anterior cerebral artery in the prechiasmatic cistern injection group was smaller than that in the cisterna magna injection group (p<0.05), but not for middle cerebral artery. We concluded that synchrotron radiation angiography provided a novel technique, which could directly evaluate cerebral vasospasm in small animal experimental subarachnoid hemorrhage models. The courses of vasospasm in these two injection models are similar; however, the model produced by prechiasmatic cistern injection is more suitable for study of anterior circulation vasospasm.

The effect of intraventricular thrombolysis in combination with low-frequency head motion after severe subarachnoid hemorrhage: interim analysis of safety, clot clearance rate and delayed cerebral ischemia

OBJECTIVE

The current clinical prospective randomized phase II study was initiated in order to analyze the effect of enhanced washout by discontinuous intraventricular thrombolysis in combination with low-frequency head-motion therapy on side effects, clot clearance rate, cerebral vasospasm and clinical outcome after severe subarachnoid hemorrhage (SAH).

METHODS

Data from 40 adult patients with aneurysmal SAH were included in this interim analysis. Patients randomized to the study group achieved additional intraventricular application of rt-PA (Actilyse(®)) bolus 5 mg every 12 h and lateral rotational therapy (RotoRest(®)). Clot clearance rate was evaluated based on computed tomography (CT). Delayed cerebral ischemia (DCI) and early clinical outcome of patients were determined.

RESULTS

No severe side effects due to the combined therapy were documented. The clot clearance rate was significantly higher in the study group than in the control group regarding the cranial and basal CT slices (p = 0.003 cranial slices and p = 0.037 basal slices). Delayed ischemic neurological deficits (DIND) were increased in the control group (p = 0.016).

CONCLUSION

The present study demonstrates that a combination of intraventricular thrombolysis and lateral rotational therapy is not associated with a higher complication rate. Furthermore, the therapy leads to a significant acceleration of the clot clearance rate.

The effect of common carotid artery occlusion on delayed brain tissue damage in the rat double subarachnoid hemorrhage model

OBJECTIVE

Delayed ischemic brain tissue damage in the time course of cerebral vasospasm in the rat double-subarachnoid hemorrhage (SAH) model has been described before. However, in order to enhance hemodynamic insufficiency during cerebral vasospasm (CVS), we performed-in a modification to the standard double-hemorrhage model-an additional unilateral common carotid artery occlusion (CCAO), expecting aggravation of brain-tissue damage in areas particularly sensitive to hypoxia.

METHODS

CVS was induced by injection of 0.25 ml autologous blood twice in the cisterna magna of Sprague-Dawley rats with and without unilateral CCAO. The animals were examined on days 2, 3, 4 and 5, and compared with the sham-operated control group without SAH. The functional deficits were graded between 0 and 3. Perfusion weighted imaging (PWI) at 3 Tesla magnetic resonance (MR) tomography was performed to assess cerebral blood flow (CBF). The brains were fixed, stained and evaluated for histological changes.

RESULTS

On day 5, the neurological state was significantly worse in rats with SAH. The relative CBF/muscle blood ratio was significantly decreased by SAH and lowest in rats with CCAO and SAH (4.5 ± 1.1 vs 2.7 ± 0.6) compared with sham (7.9 ± 1.5; p < 0.001). Basilar artery (BA) diameter was 79 ± 5 μm (SAH) vs 147 ± 4 μm (sham, p < 0.001). Neuronal cell count in the hippocampal areas CA1-CA4 was significantly reduced by SAH on day 5 (p < 0.001) and lowest in rats with SAH and CCAO.

CONCLUSIONS

CCAO leads to an aggravation of CVS-related delayed brain tissue damage in the modified rat double-SAH model.

Perfusion-CT assessment of blood-brain barrier permeability in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

The goal of this study was to determine which clinical and radiographic variables in patients with subarachnoid hemorrhage (SAH) are associated with in vivo blood-brain barrier permeability (BBBP) assessments obtained using perfusion-CT (PCT) technology.

METHODS

SAH patients with confirmed aneurysm etiology and with PCT and angiogram within 24 hours of each other were included, and relationships between clinical and imaging variables were analyzed using random-effects generalized linear models.

RESULTS

One thousand one hundred and sixty two vascular territories from 83 patients were evaluated in this study. The mean BBBP increased by severity of vasospasm on DSA, however, in multivariate analysis, only mean transit time (MTT), cerebral blood volume (CBV), and severity of hydrocephalus were significantly associated with BBBP. Increased BBBP was not associated with angiographic vasospasm severity in multivariate analysis.

CONCLUSION

Perfusion-CT assessment of BBBP may serve as a unique and useful biomarker in conjunction with angiography, additional perfusion-CT parameters, and clinical assessments, especially in characterizing microvascular dysfunction, or even in targeting treatments. However, future prospective studies will be required to definitively establish its clinical utility in the care of SAH patients.

Intraventricular hemorrhage secondary to intranidal aneurysm rupture-successful management by arteriovenous malformation embolization followed by intraventricular tissue plasminogen activator: case report

BACKGROUND AND IMPORTANCE

Intraventricular hemorrhage related to arteriovenous malformation (AVM) rupture is associated with significant morbidity and mortality. Intraventricular tissue plasminogen activator (tPA) has been used to treat spontaneous intraventricular hemorrhage. We demonstrate the successful application of endovascular occlusion to seal the rupture site of an AVM followed by intraventricular tPA.

CLINICAL PRESENTATION

A 32-year-old woman presented with a right frontoparietal parasagittal AVM abutting the motor cortex. The AVM was diagnosed when the patient was 13 years old, and she initially underwent conservative management. At the age of 30, the patient suffered an intracranial hemorrhage, leaving her with left hemiparesis. After rehabilitation, the patient regained ambulation; however, she remained spastic and hyperreflexic on the left side. Two years after her major hemorrhage, she presented for elective treatment of her AVM. The patient was advised to undergo staged embolization before surgical resection of her AVM. The initial embolization was uneventful. A second embolization was complicated by intraventricular hemorrhage and coma. The patient was treated with placement of an external ventricular drain followed by embolization of intranidal aneurysm. After embolization of the intranidal aneurysm the ruptured, the patient was treated with intraventricular tPA. The patient had rapid clearance of the intraventricular hemorrhage and significant improvement in her neurological examination, following commands 24 hours later and returning almost to baseline.

CONCLUSION

This case demonstrates the feasibility of treating AVM-related intraventricular hemorrhage with tPA if the rupture source can be confidently sealed interventionally. This strategy can be lifesaving but needs further study to ensure its safety.

Peri-operative measures for treatment and prevention of cerebral vasospasm following subarachnoid hemorrhage

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high early mortality rates. Cerebral vasospasm remains the major source of morbidity after aSAH. Angiographic evidence of vasospasm is apparent in 70% of patients, while clinical manifestation of vasospasm is present in one third of patients. Early or existing vasospasm at the time of presentation poses an additional challenge in the management of the patient, and forms the basis for this review.

METHODS

Treatment modalities for management of ruptured aneurysms in the setting of vasospasm, including timing of aneurysm surgery and peri-operative management, are reviewed. Intraoperative measures aimed at treatment of existing vasospasm and at the prevention of vasopasm are discussed.

RESULTS

Operative/endovascular means to secure the ruptured aneurysm should be performed as soon as possible to facilitate treatment of the vasospasm. Surgery performed in the presence of angiographic/symptomatic vasospasm can be associated with good outcome. Operative measures to decrease the incidence of vasospasm include clot removal, intracisternal injection of thrombolytics, fenestration of the lamina terminalis and local application of vasodilatory agents. Post-operative measures include early intra-arterial injection of vasodilators (verapamil or nicardipine), percutaneous angioplasty, triple-H therapy and CSF drainage.

DISCUSSION

The utilization of a multimodality approach to treat patients with aneurysmal subarachnoid hemorrhage presenting with existing vasospasm can result in good outcome.

CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

INTRODUCTION

We retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit.

MATERIALS AND METHODS

Sequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and >or=50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps.

RESULTS

Of 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots.

CONCLUSION

In SAH patients, if there is a macrovascular vasospasm with luminal narrowing >or=50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots.

Feasibility and safety of intrathecal nimodipine on posthaemorrhagic cerebral vasospasm refractory to medical and endovascular therapy

OBJECTIVE

The effectiveness of balloon angioplasty and intra-arterial infusion of vasodilating agents for patients suffering from severe vasospasm following aneurysmal subarachnoid haemorrhage (SAH) is often unsatisfying and there is still demand for further last resort treatment strategies. In the current prospective study, we attempted the intrathecal lavage administration of nimodipine in cases of severe cerebral vasospasm that were refractory to medical and endovascular therapy.

METHODS

Eight of 146 patients with aneurysmal SAH were included in the prospective study, which had been approved by the local ethics committee. Treatment was instituted by intraventricular nimodipine bolus (0.4 mg), followed by a continuous lumbar intrathecal infusion (0.4 mg/h). Effectiveness was monitored angiographically, with transcranial Doppler (TCD), perfusion CT (pCT), and by neurological examination during treatment course and follow-up.

RESULTS

The neurological condition improved directly in three patients and remained unchanged in four patients. Seventeen (70.8%) CT perfusion analyses revealed improved perfusion. A reduction of vasospasm was seen angiographically by digital subtraction angiography (DSA) in seven (66.6%) investigations. Additional ischaemic infarction after onset of the intrathecal therapy was documented in two (25%) patients. There were no serious adverse effects observed.

CONCLUSION

The present study has for the first time demonstrated the feasibility and safety of intrathecal nimodipine lavage in patients with severe vasospasm resistant to the established medical and endovascular treatment strategies. The results of the study are therefore encouraging, and further experimental and clinical trials should be carried out so as to investigate the efficacy of intrathecal nimodipine lavage in vasospasm therapy.

The effect of lumboventricular lavage and simultaneous low-frequency head-motion therapy after severe subarachnoid hemorrhage: results of a single center prospective Phase II trial

Object

The authors of recent publications have suggested that a combination of cisternal irrigation and head-shaking therapy might reduce cerebral vasospasm after subarachnoid hemorrhage (SAH) and therefore improve outcome. The authors undertook this prospective nonrandomized Phase II study to analyze the effect of enhanced washout by lumboventricular irrigation in combination with head motion (lateral rotational therapy) on the clot clearance (CC) rate, development of cerebral vasospasm, and clinical outcome.

Methods

Forty patients with aneurysmal SAHs of World Federation of Neurosurgical Societies Grades II–V (Glasgow Coma Scale Scores 13–3) and Fisher Grade 3 or 4 were included in this study. The study and control groups each consisted of 20 patients. The protocol in the study group, after the aneurysm was secured and a ventricular drain inserted, included the insertion of 2 lumbar catheters for intrathecal irrigation with Ringer solution and intrathecal pressure monitoring. Moderate head rotation in a kinetic system was also applied and was continued for 5 days. The CC rate was monitored on daily computed tomography (CT) scans. Vasospasms were identified clinically with a focus on delayed ischemic neurological deficits (DINDs), daily transcranial Doppler (TCD) ultrasonography studies, and analysis of infarction rate on CT and cerebral angiography. The data obtained in both groups were statistically evaluated.

Results

There were no procedure-related complications. The overall CC rate did not differ significantly between the groups, but there was a trend toward accelerated resolution in the study group. During observation, a new neurological deficit developed in 1 patient (5%) in the study group and 4 patients (20%) in the control group. Ischemic areas on CT scans related to vasospasm were demonstrated in 2 patients (10%) in the study group and 6 patients (30%) in the control group. The incidence of angiographic vasospasm was approximately the same in both groups. The pooled TCD flow velocities measured over a period of 14 days showed lower mean values in the study group than in the control group (p = 0.00002). The clinical outcome in the study group as evaluated with the modified Rankin scale was better in the study group than in the control group after 3 (p = 0.008) and 6 (p = 0.005) months.

Conclusions

The present study demonstrates that a combination of lumboventricular lavage and mechanical head motion reduces vasospasm on TCD ultrasonography, the incidence of DIND, and secondary infarctions on CT and improves clinical outcome. No obvious effect could be found on the rate of angiographic vasospasm.

Intra-arterial nimodipine for severe cerebral vasospasm after aneurysmal subarachnoid hemorrhage: influence on clinical course and cerebral perfusion

BACKGROUND AND PURPOSE

The efficacy of intra-arterial administration of nimodipine (IAN) in patients with severe vasospasm after aneurysmal subarachnoid hemorrhage (SAH) remains unproved. The goal of the present study was to investigate the clinical effect and cerebral perfusion after IAN in patients with severe vasospasm refractory to hemodynamic treatment.

MATERIALS AND METHODS

Twenty-six of 214 patients with aneurysmal SAH were included in the prospective study, approved by the local ethics committee. All patients met the criteria of medically refractory cerebral vasospasm. Effectiveness was monitored angiographically by digital subtraction angiography and by transcranial Doppler (TCD), perfusion CT (PCT), and neurologic examination during treatment course and follow-up.

RESULTS

No angiographic effect was observed in 8 patients. The pooled PCT values revealed a reduction of time to peak (P = .03) and mean transit time (P = .17) 1 day after intervention. This effect did not persist during the following days. The pooled TCD analysis demonstrated a transient increase in flow 1 day after intervention (P = .03). No trend was evident during the next 7 days after intervention. Additional infarction was experienced by 61.1% of patients.

CONCLUSIONS

IAN in a selective patient group resulted in a positive response with reduction of angiographic vasospasm and increase in cerebral perfusion as detected by PCT after 24 hours. Therefore, IAN appears more effective than intra-arterial papaverine. Nevertheless the efficacy of IAN is temporary. Therefore, the search for more effective treatment strategies to reduce critical vasospasm and to improve cerebral perfusion must be continued.

Prospective evaluation of multidetector-row CT angiography for the diagnosis of vasospasm following subarachnoid hemorrhage: a comparison with digital subtraction angiography

PURPOSE

To evaluate the accuracy of multidetector-row CT angiography (CTA) for the diagnosis of large-vessel vasospasm following subarachnoid hemorrhage by comparison to digital subtraction angiography (DSA).

METHODS

Thirty-three patients with acute subarachnoid hemorrhage were enrolled in a prospective study and underwent a total of 40 CTA and DSA examinations within 24 h of each other. Two neuroradiologists reviewed the CTA examinations independently. A third neuroradiologist blinded to the CTA results reviewed the DSA examinations. In each patient, for both techniques, 23 arterial segments were evaluated for their degree of narrowing; the reviewers were asked to attribute every narrowing to 'vasospasm' or 'hypoplasia'. Agreement between CTA and DSA for the degree of narrowing, and agreement between the two CTA readers, were calculated using weighted kappa-coefficients. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV) of CTA to detect large-vessel vasospasm were calculated considering DSA as the gold standard.

RESULTS

Substantial correlation (kappa = 0.638) was found between CTA and DSA for the detection of arterial narrowing. Interobserver agreement between the two CTA reviewers for the degree of luminal narrowing was substantial (kappa = 0.712).CTA was 87% accurate for the diagnosis of large-vessel vasospasm; the NPV of CTA was 95%. CTA was more accurate, and interobserver agreement higher, for the proximal arterial segments (basilar and vertebral arteries) than for the distal ones (P2 segments). Using CTA as a screening modality, 83% of unnecessary DSA would have been avoided.

CONCLUSION

Compared to the gold standard of DSA, CTA is accurate for the detection of large-vessel vasospasm, and has a very high NPV.

Effect of delayed cerebral vasospasm on cerebrovascular endothelin A receptor expression and function

Object

The key role in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) is increasingly assigned to endothelin (ET)-1. Constriction of the cerebrovasculature by ET-1 is mainly mediated by the ETA receptor but is putatively altered during the development of cerebral vasospasm. Therefore, the aim in the present study was to characterize these alterations, with the emphasis on the ETA receptor.

Methods

Cerebral vasospasm was induced using the rat double-hemorrhage model and proven by perfusion weighted magnetic resonance imaging. Rats were killed on Day 5 after SAH, and immunohistochemical staining for ETA receptors was performed. The isometric force of basilar artery ring segments with (E+, control group) and without (E−, SAH group) endothelial function was measured. Concentration effect curves (CECs) for ET-1 were constructed by cumulative application in the absence and presence of the selective ETA receptor antagonist clazosentan (10−8 or 10−7 M).

Results

The CEC for E+ segments was significantly shifted to the left after SAH by a factor of 3.7, whereas maximum contraction was unchanged. In E− segments, the CECs were not shifted during cerebral vasospasm but the maximum contraction was significantly enhanced. The inhibitory potency of clazosentan yielded a pA2 value of 8.6 ± 0.2. Immunohistochemical staining of the smooth-muscle layer showed no significant increase of ETA receptor expression, but positive staining occurred in the endothelial space after SAH.

Conclusions

The present data indicate an enhanced contractile effect of the smooth-muscle ETA receptors in cases of cerebral vasospasm. The inhibitory potency of clazosentan on this contraction is increased. Furthermore, some evidence for an ETA receptor and an endothelium-dependent vasoactive effect after SAH is provided.

Early-phase pharmacokinetics of enteral and parenteral nimodipine in patients with acute subarachnoid haemorrhage - a pilot study

OBJECTIVE

The pharmacokinetics of nimodipine following enteral administration in the early phase after subarachnoid haemorrhage (SAH) has not been described. If a sufficient absorption could be achieved with enterally administered nimodipine, this would be more feasible dosage form and result in a significant reduction in pharmaceutical costs given that the parenteral formulation of nimodipine currently used is tenfold more expensive than the enteral formulation.

METHODS

This was a pilot study in which 17 patients with aneurysmal SAH were randomly assigned to receive nimodipine within 24 h after initial bleeding either as an 60 mg tablet/suspension at 4-h intervals, or as a continuous intravenous infusion of 2 mg/h. Serum nimodipine concentrations were measured during the 4 h following the first dose, and at 24 and 72 h on a validated gas chromatography mass spectrometer (GC-MS).

RESULTS

Nimodipine AUC values (expressed in mug min/ml) were lower in the eight SAH patients receiving enteral nimodipine [AUC(0-4) range: 0.13-5.4 (median: 0.32); AUC(24-28) range: 0.16-6.1 (0.71); AUC(72-76) range: 0.47-20.6 (1.9)] than in the nine patients receiving a continuous intravenous infusion of nimodipine [AUC(0-4) range: 2.4-4.9 (3.4), p=0.059; AUC(24-28) range: 4.7-10.3 (7.3), p=0.001; AUC(72-76) range: 3.4-8.6 (6.9), p=0.001]. In three of five good-grade SAH patients receiving nimodipine tablets the AUC values were comparable to those of the intravenous administration, but in two good-grade patients with tablets and in all three poor-grade (Hunt&Hess, grade IV) SAH patients receiving the suspension, the rate and extent of nimodipine absorption was negligible.

CONCLUSION

This pilot study indicates that the rate and extent of nimodipine absorption following enteral administration in some acute SAH patients could be negligible, and this may particularly be the case in patients with a decreased level of consciousness.

PERSISTENCE OF THE NITRIC OXIDE-DEPENDENT VASODILATORPATHWAY OF CEREBRAL VESSELS AFTEREXPERIMENTAL SUBARACHNOID HEMORRHAGE

OBJECTIVE

Efficiency of the treatment of cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) by interfering with the nitric oxide-cyclic guanosine monophospate (cGMP) pathway seems to be inconsistent. So far, it remains unclear whether or not insufficient access to the drugs or impaired reactivity of the vessels is responsible for this inconsistency. Therefore, the aim of the present investigation was to characterize this pathway on cerebral arteries during CVS.

METHODS

CVS was induced using the rat double hemorrhage model and was determined by magnetic resonance perfusion weighted imaging. Rats were sacrificed on Day 3 and Day 5 after SAH. Immunohistochemical staining of the basilar artery for endothelial nitric oxide synthases and the alpha- and beta-subunits of the soluble guanylate cyclase was performed. Basilar artery ring segments on Day 5 were used for measurement of isometric force. Concentration effect curves for acetylcholine, sodium nitroprusside, and 8-bromo-cGMP were constructed and compared by maximum effect and pD2.

RESULTS

The immunohistochemical expression of endothelial nitric oxide synthase was comparable in all groups. The soluble guanylate cyclase alpha- and beta-subunits were significantly diminished on Day 3, but recovered by Day 5. The relaxation attributable to acetylcholine and 8-bromo-cGMP was virtually identical in controls and during CVS. Relaxation attributable to sodium nitroprusside, however, was significantly enhanced after SAH (maximum effect, control: 88 +/- 12%; Day 5: 117 +/- 26%).

CONCLUSION

The present investigations suggest the persistence of endothelium-, nitric oxide-, and cGMP-dependent relaxation during CVS. Therefore, the treatment of CVS interfering with this pathway seems not to be limited by alterations inside the vessel wall.

Comparison between clipping and coiling on the incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Cerebral vasospasm is one of the most important complications of aneurysmal subarachnoid hemorrhage. The effect of aneurysm occlusion technique on incidence of vasospasm is not exactly known. The objective was to analyze surgical clipping versus endovascular coiling on the incidence of cerebral vasospasm and its consequences. Using the MEDLINE PubMed (1966-present) database, all English-language manuscripts comparing patients treated by surgical clipping with patients treated by endovascular coiling, regarding vasospasm incidence after aneurysmal subarachnoid hemorrhage, were analyzed. Data extracted from eligible studies included the following outcome measures: incidence of total vasospasm, symptomatic vasospasm, ischemic infarct vasospasm-induced and delayed ischemic neurological deficit (DIND). A pooled estimate of the effect size was computed and the test of heterogeneity between studies was carried out using The Cochrane Collaboration's Review Manager software, RevMan 4.2. Nine manuscripts that fulfilled the eligibility criteria were included and analyzed. The studies differed substantially with respect to design and methodological quality. The overall results showed no significant difference between clipping and coiling regarding to outcome measures. According to the available data, there is no significant difference between the types of technique used for aneurysm occlusion (clipping or coiling) on the risk of cerebral vasospasm development and its consequences.

Predictors of left ventricular regional wall motion abnormalities after subarachnoid hemorrhage

INTRODUCTION

Cardiac abnormalities that have been reported after subarachnoid hemorrhage (SAH) include the release of cardiac biomarkers, electrocardiographic changes, and left ventricular (LV) systolic dysfunction. The mechanisms of cardiac dysfunction after SAH remain controversial. The aim of this study was to determine the prevalence of LV regional wall motion abnormalities (RWMA) after SAH and to quantify the independent effects of specific demographic and clinical variables in predicting the development of RWMA.

METHODS

Three hundred patients hospitalized with SAH were prospectively studied with serial echocardiography. The primary outcome measure was the presence of RWMA. The predictor variables included the admission Hunt & Hess grade, age, gender, cardiac risk factors, aneurysm location, plasma catecholamine levels, cardiac troponin I (cTi) level, heart rate (HR), blood pressure, and phenylephrine dose. Univariate and multivariate logistic regression was performed with adjustment for serial measurements, reporting odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

In this study, 817 echocardiograms were analysed. RWMA were detected in 18% of those studied. The prevalence of RWMA in patients with Hunt & Hess grades 3 - 5 was 35%. Among patients with a peak cTi level greater than 1.0 m g/L, 65% had RWMA. Multivariate analysis demonstrated that high Hunt & Hess grade (OR 4.22 for grade 3 - 5 versus grade 1 - 2, p = 0.046), a cTi level greater than 1.0 microg/L (OR 10.47, p = 0.001), a history of prior cocaine or amphetamine use (OR 5.50, p = 0.037), and higher HR (OR 1.34 per 10 bpm increase, p = 0.024) were predictive of RWMA.

CONCLUSIONS

RWMA were frequent after SAH. High-grade SAH, an elevation in cTi levels, a history of prior stimulant drug use, and tachycardia are independent predictors of RWMA.

Computed tomography grading schemes used to predict cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a historical review

✓The elucidation of predictive factors of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major area of both clinical and basic science research. It is becoming clear that many factors contribute to this phenomenon. The most consistent predictor of vasospasm has been the amount of SAH seen on the postictal computed tomography scan. Over the last 30 years, it has become clear that the greater the amount of blood within the basal cisterns, the greater the risk of vasospasm. To evaluate this risk, various grading schemes have been proposed, from simple to elaborate, the most widely known being the Fisher scale. Most recently, volumetric quantification and clearance models have provided the most detailed analysis. Intraventricular hemorrhage, although not supported as strongly as cisternal SAH, has also been shown to be a risk factor for vasospasm.

Time Course in the Development of Cerebral Vasospasm after Experimental Subarachnoid Hemorrhage: Clinical and Neuroradiological Assessment of the Rat Double Hemorrhage Model

OBJECTIVE

The "double hemorrhage" model in the rat is frequently used to simulate delayed cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in humans. However, an exact neurological and angiographic characterization of the CVS is not available for this model so far and is provided in the present investigation. Additionally, perfusion weighted imaging (PWI) at 3 tesla magnetic resonance (MR) tomography was implemented to assess the reduction in cerebral blood flow (CBF).

METHODS

In a prospective, randomized setting CVS was induced by injection of 0.2 ml autologous blood twice in the cisterna magna of 45 male Sprague-Dawley rats. The surviving animals were examined on Days 2, 3, 5, 7 and 9 and compared to a sham operated control group (n = 9). Rats were neurologically graded between 0 and 3, followed by MRI and selective digital subtraction angiography (DSA). The relative CBF was set in relation to the perfusion of the masseter muscle.

RESULTS

The neurological state was significantly worsened on Day 2 (Grade 3), 3 (Grade 3), and 5 (Grade 2) (medians). The relative CBF/muscle BF ratio (2.5 +/- 0.8 (SAH) versus 9.2 +/- 1.3 (sham) (mean +/- SEM) and the basilar artery (BA) diameter (0.15 +/- 0.02 mm (SAH) versus 0.32 +/- 0.01 mm (sham) were significantly decreased on Day 5. Correlation between relative CBF/muscle BF ratio and BA diameter was 0.70.

CONCLUSION

A valid and reproducible CVS simulation was proven by neurological score, DSA, and PWI on Day 5. Furthermore, our data demonstrate the practicability and validity of MR PWI for the monitoring of CVS in a rat SAH model.

Ambrisentan, a Non-peptide Endothelin Receptor Antagonist

Increasing numbers of experimental investigations and recently also of clinical trials strongly suggest an integral involvement of the endothelin (ET)-system in the pathophysiology of a variety of disease states, mainly of the cardiovascular system. Ambrisentan (LU 208075), a selective ET(A)-receptor antagonist, is an orally active diphenyl propionic acid derivative. It has been shown to have a very promising efficacy to safety ratio in the initial clinical trials. Phase II and Phase III trials with ambrisentan in pulmonary arterial hypertension have been performed. The pharmacological properties and data from the experimental investigations suggest additional possible uses of ambrisentan in the prevention of reperfusion injury after organ transplantation and in restenosis following coronary artery dilatation. Furthermore, the pharmacological profile of ambrisentan indicates that this drug may also be suitable in the treatment of cerebrovascular disorders. In the present article basic investigations, animal studies and clinical trials with ambrisentan are reviewed. This review may help to define pathophysiological conditions, in which ambrisentan could be indicated and further evaluated in appropriate preclinical and clinical trials.

Outcome of Surgical Clipping of Unruptured Aneurysms as it Compares with a 10-Year Nonclipping Survival Period

OBJECTIVE

Recent studies on the natural history of unruptured intracranial aneurysms dictate that we reevaluate the risks and benefits of surgical intervention as it compares with the natural course. We analyzed the outcome of surgical clipping of a patient cohort with unruptured aneurysms as it compares with a 10 year nonclipping survival period on the basis of two previously published studies (International Study on Unruptured Intracranial Aneurysms and a study by Juvela et al. [36] from Helsinki).

METHODS

Data on 148 unruptured aneurysms in 116 consecutive surgically treated patients were prospectively recorded and retrospectively analyzed. The overall majority were diagnosed with cerebral angiography. Data analyzed included aneurysmal properties and clinical outcomes including surgical related mortalities and morbidities. The observed outcomes were compared with the expected outcome of a 10 year nonclipping survival period if the patient cohort was included in recently reported studies on unruptured aneurysms. More than 1 year follow-up was available in 93.1% (108) of patients and follow-up cerebral angiography was performed in 80% (93) of patients.

RESULTS

Mean age was 53.57 years. There were 25 (16.8%) small aneurysms (less than 7 mm), 70 (47.2%) aneurysms 7 to 12 mm in size, 41 (27.70%) large (13-24 mm), and 12 (8.10%) giant (>25 mm) aneurysms. Posterior circulation aneurysm comprised 13.51%. One hundred forty-three (96.62%) aneurysms were successfully clipped, and 3.37% were either wrapped or later coiled. Surgical-related mortality was 0.82% (1 patient because of air embolism). Surgical related permanent morbidity was 3.44% (4 patients) and transient surgical-related mild morbidities was 7.7% (9 patients). Immediate postsurgical good outcome (Glasgow Outcome Score = 4-5) was 87.93% (102 patients) and 95.68% in 3 months (111 patients). At 1 year, the modified Rankin scale scores were 0 to I = 102, II = 3, III = 2, IV = 1, and V = 0. Residual aneurysms were seen in none of the postoperative angiograms (93 patients). Using the chi method, the comparison of the expected to the observed mortality and morbidity revealed a statistically significant difference in the mortality in favor of surgical clipping (P = 0.034 when compared with the International Study on Unruptured Intracranial Aneurysms and P = 0.05 when compared with the Juvela et al. [36] study). There was no statistically significant difference in the permanent morbidity.

CONCLUSION

Studies on natural history of unruptured intracranial aneurysms suggest 10 year cumulative bleeding-related mortality and severe morbidity of no less than 7.5%. In our study, surgical clipping resulted in an 0.8% rate of mortality and 3.4% permanent morbidity. This suggests that surgical clipping has the potential of a superior outcome to the natural history of patients who have an estimated life expectancy of no less than 10 years.

Reduction of pulmonary edema after SAH with a pulmonary artery catheter-guided hemodynamic management protocol

INTRODUCTION

The frequency of pulmonary edema, which occurs with high frequency following subarachnoid hemorrhage (SAH), can be worsened by hypervolemic, hypertensive, hemodilution therapy for vasospasm. This study compares the complication rates for patients with SAH before and after institution of a pulmonary artery catheter-guided hemodynamic management protocol.

METHODS

Complication and outcome data were prospectively collected on 453 patients with spontaneous SAH. The patients were divided into groups treated from July 1998 through January 2000 (n = 174) and from February 2002 through June 2002 (n = 279). In group I, treatment consisted of hypervolemia (central venous pressures: >8 mmHg) and hypertension (mean arterial pressure: 110-130 mmHg). In group II, normovolemia was the goal, defined using a pulmonary artery catheter (wedge pressure: 10-14 mmHg). Cardiac output was enhanced (index: >4.5 L/minute/m2), and blood pressure elevations were moderated (mean pressure: >100 mmHg).

RESULTS

The average age, comorbidity, hemorrhage severity, and incidence of vasospasm were almost identical between the two groups. Statistically significant reductions were noted in patients in group II for two types of complications as well as for mortality. The rate of pulmonary edema (from 14 to 6%) and the rate of sepsis (from 14 to 6%) were both decreased (p <or= 0.03). Mortality decreased from 34 to 29% (p = 0.04). Other complications, such as myocardial infarction, were not affected.

CONCLUSIONS

These data show that a significant reduction in the frequency of pulmonary edema after SAH can be attained using a pulmonary artery catheter-guided hemodynamic management protocol.

Complications of endovascular treatment of cerebral aneurysms

BACKGROUND

The International Subarachnoid Aneurysm Trial has indicated that endovascular management of acutely ruptured aneurysms may be superior to surgery. Clearly poor results ensue from both forms of treatment, and some of these are because of technical complications (not just poor patient status). This observational study was performed to determine the complications associated with the endovascular treatment of ruptured and unruptured cerebral aneurysms.

METHODS

Prospective data were gathered on 118 patients undergoing 126 endovascular treatment sessions for 126 nontraumatic cerebral aneurysms (30% unruptured) over a 3-year period. The average age was 51 years (range, 12-85 years). Females comprised 75% of the population treated.

RESULTS

Good outcomes were achieved with 71% of the procedures (59% for subarachnoid hemorrhage [SAH]; 97% for unruptured). No bleeding or rebleeding occurred from treated aneurysms. Vessel or aneurysm perforation occurred in 11 cases and led to adverse outcome in 3 (3%). Thromboembolic complications were felt to cause cerebral infarction in 8 cases (6%). The risk of vessel/aneurysm rupture or thromboembolic stroke was greater in patients with SAH. Eight attempts to coil (6%) were initially unsuccessful. Two of these were later successfully coiled and others had surgery. None of the failed attempts led to clinical deterioration. Balloon-assisted coiling (BAC) was not associated with an increased complication rate.

CONCLUSIONS

Vessel perforation and thromboembolic stroke are significant risks of endovascular treatment, especially after SAH. In our hands, however, BAC does not add to this risk.

Cerebrovascular characterization of clazosentan, the first nonpeptide endothelin receptor antagonist clinically effective for the treatment of cerebral vasospasm. Part I: Inhibitory effect on endothelinA receptor—mediated contraction

Object. The central role of endothelin (ET)—1 in the development of cerebral vasospasm after subarachnoid hemorrhage is indicated by the successful treatment of this vasospasm in several animal models by using selective ETA receptor antagonists. Clazosentan is a selective ETA receptor antagonist that provides for the first time clinical proof that ET-1 is involved in the pathogenesis of cerebral vasospasm. The aim of the present investigation was, therefore, to define the pharmacological properties of clazosentan that affect ETA receptor—mediated contraction in the cerebrovasculature.

Methods. Isometric force measurements were performed in rat basilar artery (BA) ring segments with (E+) and without (E−) endothelial function. Concentration effect curves (CECs) were constructed by cumulative application of ET-1 or big ET-1 in the absence or presence of clazosentan (10−9, 10−8, and 10−7 M). The inhibitory potency of clazosentan was determined by the value of the affinity constant (pA2).

The CECs for contraction induced by ET-1 and big ET-1 were shifted to the right in the presence of clazosentan in a parallel dose-dependent manner, which indicates competitive antagonism. The pA2 values for ET-1 were 7.8 (E+) and 8.6 (E−) and the corresponding values for big ET-1 were 8.6 (E+) and 8.3 (E−).

Conclusions. The present data characterize clazosentan as a potent competitive antagonist of ETA receptor—mediated constriction of the cerebrovasculature by ET-1 and its precursor big ET-1. These functional data may also be used to define an in vitro profile of an ET receptor antagonist with a high probability of clinical efficacy.

Swedish Council on Technology Assessment in Health Care (SBU). Chapter 8. Sick leave due to coronary artery disease or stroke

The assessment of the literature on sick-leave with cardiovascular diseases include only studies with sufficient scientific quality. These studies describe sick leave following stroke, myocardial infarction, coronary artery bypass grafting (CABG), or percutaneous coronary intervention (PCI). We found limited scientific evidence for the following results: After stroke, more than half of the patients of working age returned to work (RTW) during the first year following onset (higher rate for the younger patients). The consequences of brain damage, e.g. impaired ADL ability or cognitive capacity, play an important role in this respect. Also after myocardial infarction most patients RTW. PCI is a milder coronary artery intervention than CABG and RTW is more rapid. However, in the long run there are no differences in sick leave. People at higher ages or with physically demanding jobs return to work to a lesser degree. An international comparison shows that the duration of sick leave due to these conditions in Sweden is longer than in other countries although there is no scientific evidence to support this practice. It appears that the interest in research on sick leave in patients with cardiovascular diseases has waned in recent years. Developments in acute cardiological care should inspire renewed scientific involvement in this area of research.

Acute alterations in microvascular basal lamina after subarachnoid hemorrhage

Object. Aneurysmal subarachnoid hemorrhage (SAH) causes acute and delayed ischemic brain injuries. The mechanisms of acute ischemic injury following SAH are poorly understood, although an acute increase in microvascular permeability has been noted. The integrity of cerebral microvessels is maintained in part by components of basal lamina: collagen IV, elastin, lamina, and so forth. Destruction of basal lamina components by collagenases and matrix metalloproteinases (MMPs), especially MMP-9, has been known to occur in other ischemic models. The authors assessed the integrity of cerebral microvasculature after acute SAH by examining collagen IV and MMP-9 levels and collagenase activity in the microvessels.

Methods. Subarachnoid hemorrhage was induced in rats through endovascular perforation of the intracranial bifurcation of the internal carotid artery. Animals were killed 10 minutes to 48 hours after SAH or sham operation (time-matched controls). Levels of collagen IV and MMP-9 were studied in the microvasculature by performing immunoperoxidase and immunofluorescence staining, and collagenase activity was assessed by in situ zymography.

Little change occurred in collagen IV and MMP-9 immunostaining or collagenase activity at 10 minutes or 1 hour after SAH. Starting 3 hours after SAH, collagen IV immunostaining was reduced or eliminated along segments of microvessels whereas MMP-9 staining was segmentally increased. These effects reached a maximum at 6 hours and returned toward those values in sham-operated controls at 48 hours.

Conclusions. Results of this study demonstrated an acute loss of collagen IV from the cerebral microvasculature after SAH and indicated that MMP-9 contributes to this event. The loss of collagen IV might contribute to the known failure of the blood—brain barrier after SAH.

Early surgery-related complications after aneurysm clip placement: an analysis of causes and patient outcomes

Object. Most reports of series on ruptured intracranial aneurysms contain information on select intraoperative complications. An understanding of all surgical complications, however, may guide us toward improved surgical procedures and enrich discussions concerning alternative management strategies, such as endovascular treatment, which are not exempt from complications and aneurysm recurrence.

Methods. The study consists of a retrospective review of the charts, images, and notes from follow-up visits of 143 consecutive patients with subarachnoid hemorrhage (SAH) who were surgically treated during a 3-year period by one neurosurgeon. A surgical complication was determined based on findings of a clinical and/or radiological study in the absence of confounding factors such as the initial SAH ictus, vasospasm, hydrocephalus, and septic status. Functional outcome was assessed between 2 and 3 months post-SAH by using the Glasgow Outcome Scale (GOS). A procedure-related surgical complication was diagnosed in 29 (20.3%) of 143 patients studied. A brain tissue injury, including cerebral edema and hemorrhagic contusions, was diagnosed in 6.3% of patients, an unpredicted residual aneurysm neck in 5.3% of patients, and a cranial nerve deficit in 2.8% of patients. Functional outcome was good in 22 (75.9%) of the 29 patients with surgical complications. Death due to a surgical complication occurred in one (0.7%) of 143 patients.

Conclusions. Surgical complications are more prevalent than previously thought. They may have been overlooked previously because of the high percentage of good functional outcomes and low mortality rates in this group. The identification of surgical complications may encourage the search for solutions to improve surgical treatment of aneurysmal SAH.

Marked reduction of cerebral vasospasm with lumbar drainage of cerebrospinal fluid after subarachnoid hemorrhage

OBJECT

Cerebral vasospasm after subarachnoid hemorrhage (SAH) continues to be a major source of morbidity in patients despite significant clinical and basic science research. Efforts to prevent vasospasm by removing spasmogens from the subarachnoid space have produced mixed results. The authors hypothesize that lumbar cisternal drainage can remove blood from the basal subarachnoid spaces more effectively than an external ventricular drain (EVD). This non-randomized, controlled-cohort study was undertaken to evaluate the effectiveness of a lumbar drain in patients with SAH compared with those in whom an EVD or no form of cerebrospinal fluid (CSF) drainage was used to prevent the development of clinical vasospasm and its sequelae.

METHODS

The authors collected data on 266 patients with nontraumatic SAH who were admitted to the University of Utah Health Sciences Center between January 1994 and January 2003. Of these, 167 met the study entry criteria. The treatment group consisted of 81 patients in whom a lumbar drain had been placed for CSF shunting, whereas the control group was composed of 86 patients who received no form of CSF drainage or who were treated solely with an EVD. Primary outcome measures were as follows: 1) clinically evident vasospasm; 2) the need for endovascular intervention; 3) vasospasm-induced infarction; 4) disposition at time of discharge; and 5) Glasgow Outcome Scale (GOS) score at 1 to 3 months postdischarge. Secondary outcomes included length of stay and the need for CSF shunting. The presence of a lumbar drain conferred a statistically significant protective and beneficial effect across all outcome measures, reducing the incidence of clinical vasospasm from 51 to 17%, the need for angioplasty from 45 to 17%, and the occurrence of vasospastic infarction from 27 to 7% (all p < or = 0.001-0.008). Patients in the treatment group were more likely to be discharged home (54% compared with 25%, p = 0.002) and to have a GOS score of 5 at follow up (71% compared with 35%, p < 0.001). The mean number of days spent in the intensive care unit and in the hospital overall was also fewer in the treatment group. A similar degree of benefit was found in patients with different Fisher grades and regardless of whether an EVD was needed on presentation, both by subgroup analysis and multivariate logistic regression modeling. There was no statistical difference between the groups in terms of patients requiring a shunt. Complications with lumbar drains were rare and yielded no permanent sequelae.

CONCLUSIONS

Shunting of CSF through a lumbar drain after an SAH markedly reduces the risk of clinically evident vasospasm and its sequelae, shortens hospital stay, and improves outcome. Its beneficial effects are probably mediated through the removal of spasmogens that exist in the CSF. The results of this study warrant a randomized clinical trial, which is currently under way.

Does Intracisternal Thrombolysis Prevent Vasospasm after Aneurysmal Subarachnoid Hemorrhage? A Meta-analysis

OBJECTIVE

Despite existing strategies for the treatment of vasospasm after aneurysmal subarachnoid hemorrhage, vasospasm remains a persistent contributor to death and disability. The intracisternal application of thrombolytic agents to dissolve subarachnoid clot has been advocated. The goal of this analysis was to assess the currently available evidence regarding the effectiveness of this treatment.

METHODS

We conducted a systematic review of the published literature; all controlled trials were included. The outcomes of interest were delayed ischemic neurological deficits, poor Glasgow Outcome Scale scores, and death. A formal meta-analysis was performed with a random-effects model.

RESULTS

The search revealed nine trials or trial subgroups (only one of which was randomized), with a total enrollment of 652 patients. Pooled results demonstrated beneficial effects of treatment, with absolute risk reductions of 14.4% (95% confidence interval, 6.5–22.5%; P &lt; 0.001) for delayed ischemic neurological deficits, 9.5% (95% confidence interval, 4.2–14.8%; P &lt; 0.01) for poor Glasgow Outcome Scale scores, and 4.5% (95% confidence interval, 1.5–7.5%; P &lt; 0.05) for death. Regression analysis revealed that treatment effects did not significantly differ among the studies on the basis of the type of thrombolytic agent used (tissue plasminogen activator versus urokinase) or the method of administration (intraoperative versus postoperative) (P &gt; 0.10). Studies that enrolled only patients at high risk for vasospasm seemed to demonstrate greater treatment effects.

CONCLUSION

The meta-analysis suggests a clinically relevant and statistically significant beneficial effect of intracisternal thrombolysis. However, the results of the analysis are limited by the predominance of nonrandomized studies. Further randomized, blinded, placebo-controlled trials of high-risk patients would be justified.