Efficacy of steroid hormone in solution for intracranial irrigation during aneurysmal surgery for prevention of the vasospasm syndrome

Cisternal and intraventricular irrigation in subarachnoid and intraventricular haemorrhage

BACKGROUND

Subarachnoid haemorrhage (SAH) and intraventricular haemorrhage (IVH) are associated with poor patient outcomes. Intraventricular fibrinolysis is effective in clearing IVH and improving patient survival and neurological outcome. By similar rationale, cisternal irrigation has been proposed as a potential method to accelerate haematoma clearance in SAH. We aimed to provide a comprehensive review and meta-analysis evaluating the effect of intraventricular and cisternal irrigation on clinical outcomes in patients with SAH and IVH.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed preparing this systematic review and study selection was performed by multiple investigators. We extracted ORs from the individual studies and aggregated these using a random effects model. The quality of evidence was evaluated using Grading of Recommendations, Assessment, Development and Evaluations assessment and ROBINS-I or RoB-2.

RESULTS

24 articles were included. In SAH, we found that cisternal irrigation with fibrinolytic agents was associated with reduced mortality (OR: 0.68, 95% CI 0.46 to 1.00), higher probability of favourable functional outcome (OR: 1.80, 95% CI 1.30 to 2.51), and reduced risks of DCI (OR: 0.28, 95% CI 0.18 to 0.42) and cerebral vasospasm (OR: 0.28, 95% CI 0.18 to 0.42), compared with conventional therapy. Cisternal irrigation with vasodilatory agents was associated with lower mortality (OR: 0.32, 95% CI 0.13 to 0.79) and reduced risk of cerebral vasospasm (OR: 0.37, 95% CI 0.17 to 0.79). The evidence for irrigation therapy of IVH was sparse and insufficient to show any significant effect.

CONCLUSION

In this study, we found that cisternal irrigation could improve the prognosis in patients with SAH compared with conventional therapy. There is no evidence to support cisternal irrigation treatment of IVH.

Cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery

BACKGROUND

During aortic aneurysm surgery, cross-clamping can lead to inadequate blood supply to the spinal cord resulting in neurological deficit. Cerebrospinal fluid drainage (CSFD) may increase the perfusion pressure to the spinal cord and hence reduce the risk of ischaemic spinal cord injury.

OBJECTIVES

To determine the effect of CSFD during thoracic and thoracoabdominal aortic aneurysm (TAAA) surgery on the risk of developing spinal cord injury.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 31 2012) and CENTRAL (2012, Issue 5) for publications describing randomised controlled trials of cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery. Reference lists of relevant articles were checked.

SELECTION CRITERIA

Randomised trials involving CSFD during thoracic and TAAA surgery.

DATA COLLECTION AND ANALYSIS

Both authors assessed the quality of trials independently. SNK extracted data and GS verified the data.

MAIN RESULTS

Three trials with a total of 287 participants operated on for Type I or II TAAA were included.In the first trial of 98 participants, neurological deficits in the lower extremities occurred in 14 (30%) of CSFD group and 17 (33%) controls. The deficit was observed within 24 hours of the operation in 21 (68%), and from three to 22 days in 10 (32%) participants. CSFD did not have a significant benefit in preventing ischaemic injury to the spinal cord.The second trial of 33 participants used a combination of CSFD and intrathecal papaverine. It showed a statistically significant reduction in the rate of postoperative neurological deficit (P = 0.039), compared to controls. Analysis was undertaken after only one third of the estimated sample size had entered the trial.In the third trial TAAA repair was performed on 145 participants. CSFD was initiated during the operation and continued for 48 hours after surgery. Paraplegia or paraparesis occurred in 9 of 74 participants (12.2%) in the control group versus 2 of 82 participants (2.7%) receiving CSFD (P = 0.03). Overall, CSFD resulted in an 80% reduction in the relative risk of postoperative deficits. Meta-analysis showed an odds ratio (OR) of 0.48 (95 % confidence interval (CI) 0.25 to 0.92). For CSFD-only trials, OR was 0.57 (95% CI 0.28 to 1.17) and for intention-to-treat analysis in CSFD-only studies, the OR remained unchanged.

AUTHORS' CONCLUSIONS

There are limited data supporting the role of CSFD in thoracic and thoracoabdominal aneurysm surgery for prevention of neurological injury. Further clinical and experimental studies are indicated.

Glucocorticoid therapy in neurologic critical care

BACKGROUND

The pivotal role of inflammation and edema across the spectrum of central nervous system injury has driven extensive investigation into the therapeutic potential of glucocorticoids.

OBJECTIVE

To review the experimental and clinical data relating to the efficacy and adverse effects of glucocorticoids in conditions encountered in critical neurologic and neurosurgical illness.

DATA SOURCE

Search of MEDLINE and Cochrane databases, manual review of article bibliographies.

DATA SYNTHESIS AND CONCLUSIONS

The efficacy of glucocorticoids is well established in ameliorating edema associated with brain tumors and in improving outcome in subsets of patients with bacterial meningitis. Despite frequently encouraging experimental results, clinical trials of glucocorticoids in ischemic stroke, intracerebral hemorrhage, aneurysmal subarachnoid hemorrhage, and traumatic brain injury have not shown a definite therapeutic effect. The evidence supporting glucocorticoid therapy for spinal cord injury is controversial; however methylprednisolone continues to be widely employed in this setting.

Cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery

BACKGROUND

During aortic aneurysm surgery, cross-clamping can lead to inadequate blood supply to the spinal cord resulting in neurological deficit. Cerebrospinal fluid drainage (CSFD) may increase the perfusion pressure to the spinal cord and hence reduce the risk of ischaemic spinal cord injury.

OBJECTIVES

To determine the effect of CSFD during thoracic and thoracoabdominal aortic aneurysm (TAAA) surgery on the risk of developing spinal cord injury.

SEARCH STRATEGY

The reviewers searched the Cochrane Peripheral Vascular Diseases Group Specialised Trials Register (last searched October 2003), the Cochrane Central Register of Controlled Trials (CENTRAL) database (last searched Issue 4, 2003), MEDLINE and EMBASE, and reference lists of relevant articles. Recent conference proceedings were scanned.

SELECTION CRITERIA

Randomised trials involving CSFD during thoracic and TAAA surgery.

DATA COLLECTION AND ANALYSIS

Both reviewers assessed the quality of trials independently. One reviewer (SNK) extracted data and the other reviewer (GS) verified the data.

MAIN RESULTS

Three trials, with a total of 287 participants operated on for type I or II TAAA, were included. In the first trial of 98 patients, neurological deficits in the lower extremities occurred in 14 (30%) CSFD and 17 (33%) controls. The deficit was observed within 24 hours of the operation in 21 (68%), and from 3 to 22 days in 10 (32%). CSFD did not have a significant benefit in preventing ischaemic injury to the spinal cord. The second trial of 33 patients used a combination of CSFD and intrathecal papaverine. It showed a statistically significant reduction in the rate of postoperative neurological deficit (p = 0.039), compared to controls. Analysis was undertaken after only one third of the estimated sample size had entered the trial. In the third trial TAAA repair was performed on 145 patients. CSFD was initiated during the operation and continued for 48 hours after surgery. Paraplegia or paraparesis occurred in 9 of 74 patients (12.2%) in the control group versus 2 of 82 patients (2.7%) with CSFD (p = 0.03). Overall, CSFD resulted in an 80% reduction in the relative risk of postoperative deficits. Meta-analysis showed an odds ratio (OR) of 0.48 (0.25 to 0.92; confidence interval (CI) 95%). For CSFD trials only OR was 0.57 (0.28 to 1.17) and for intention-to-treat in CSFD only studies OR remained unchanged.

REVIEWER'S CONCLUSIONS

There are limited data supporting the role of CSFD in thoracic and thoracoabdominal aneurysm surgery for prevention of neurological injury. Further clinical and experimental studies are indicated.

Dexamethasone in the treatment of subarachnoid hemorrhage revisited: a comparative analysis of the effect of the total dose on complications and outcome

The benefit of dexamethasone in aneurysmal subarachnoid hemorrhage (SAH) is unproven. This actual study re-examined the impact on complications and outcome. Two hundred and forty-two patient records were analyzed. Dexamethasone had been prescribed individually. Group A consisted of patients in WFNS-grade I to III that were given at least 12mg/day dexamethasone for at least five days. All other patients in WFNS-grade I to III were assigned to group B. Groups C and D resulted from WFNS-grades IV and V, subdivided according to dexamethasone medication as groups A and B. Hydrocephalus and re-hemorrhage were significantly less frequent in group A than B (19% vs. 37%, P=0.011, and 3% vs. 13%, P=0.037, respectively). Favorable outcomes (Glasgow Outcome Scale, GOS 4 and 5) were more frequent in group A than B (99% vs. 85%; P=0.003). Frequencies of vasospasm and infections did not differ. In groups C and D significant differences were demonstrated for frequencies of hydrocephalus (C: 16%, D: 57%; P=0.006) and complications other than infection (C: 33%, D: 79%; P=0.002). Favorable outcomes were more frequent in group C than D (79% vs. 47%; P=0.046). Frequencies of vasospasm and infections did not differ.

High-dose methylprednisolone prevents vasospasm after subarachnoid hemorrhage through inhibition of protein kinase C activation

We have previously shown that the inflammatory process after subarachnoid hemorrhage causes vasospasm. The efficacy of methylprednisolone by suppression of the inflammatory process has been reported, although pharmacological mechanisms have not been clarified. The purpose of this study was to investigate the pharmacological mechanism of methylprednisolone on vasospasm. Using the 'two-hemorrhage' canine model, progression of angiographic vasospasm was assessed in nontreated and treated groups with methylprednisolone. Methylprednisolone 10 mg kg-1 was injected i.v. after the first injection of blood, and the same dose was injected every 12 h until day 7. Protein kinase C (PKC) activity of canine basilar arteries in both groups was measured during the course of vasospasm. In the isometric tension study, the effect of methylprednisolone on tensions induced by phorbol 12-myristate 13-acetate (PMA), or high-K+ solution, was also evaluated. Methylprednisolone significantly reduced severity of vasospasm. In the treated group, PKC activity was not enhanced compared with the nontreated group at any point. Methylprednisolone inhibited tonic tension induced by PMA, but not that induced by high-K+ solution. We conclude that methylprednisolone prevents severity of vasospasm through inhibition of PKC activation, but does not work as a Ca2+ channel blocker.

Cerebrovascular inflammation following subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage frequently results in complications including intracranial hypertension, rebleeding and vasospasm. The extravasated blood is responsible for a cascade of reactions involving release of various vasoactive and pro-inflammatory factors (several of which are purported to induce vasospasm) from blood and vascular components in the subarachnoid space. The authors review the available evidence linking these factors to the development of inflammatory lesions of the cerebral vasculature, emphasizing: 1) neurogenic inflammation due to massive release of sensory nerve neuropeptides; 2) hemoglobin from lysed erythrocytes, which creates functional lesions of endothelial and smooth muscle cells; 3) activity, expression and metabolites of lipoxygenases cyclooxygenases and nitric oxide synthases; 4) the possible role of endothelin-1 as a pro-inflammatory agent; 5) serotonin, histamine and bradykinin which are especially involved in blood-brain barrier disruption; 6) the prothrombotic and pro-inflammatory action of complement and thrombin towards endothelium; 7) the multiple actions of activated platelets, including platelet-derived growth factor production; 8) the presence of perivascular and intramural macrophages and granulocytes and their interaction with adhesion molecules; 9) the evolution, origins, and effects of pro-inflammatory cytokines, especially IL-1, TNF-alpha and IL-6. Human and animal studies on the use of anti-inflammatory agents in subarachnoid hemorrhage include superoxide and other radical scavengers, lipid peroxidation inhibitors, iron chelators, NSAIDs, glucocorticoids, and serine protease inhibitors. Many animal studies claim reduced vasospasm, but these effects are not always confirmed in human trials, where symptomatic vasospasm and outcome are the major endpoints. Despite recent work on penetrating vessel constriction, there is a paucity of studies on inflammatory markers in the microcirculation.

A hypothesis accounting for the inconsistent benefit of glucocorticoid therapy in closed head trauma

Because of disagreement between clinical studies, the American College of Neurological Surgeons (ACNS) most recent recommendation (1996) is that glucocorticoids should not be used in the treatment of closed head trauma (CHT). The current paper reviews clinical studies of glucocorticoids and CHT in order to examine what factors might have accounted for the inconsistent results leading to the ACNS's recommendation. A careful analysIs of these studies reveals that, contrary to the ACNS's sweeping conclusion, the available data support the use of glucocorticoids for patients with CHT, but only in specific cases. Glucocorticoids may be beneficial in the treatment of CHT uncomplicated by intracranial hemorrhage; in situations where intracranial hemorrhage accompanies CHT, glucocorticoid treatment appears detrimental. The second part of this paper examines possible mechanisms accounting for the differential effectiveness of glucocorticoids in CHT patients with and without intracranial hemorrhage. These mechanisms include vasospasm, free radical damage, blood-borne factors, and glutamate neurotoxicity.

Spinal cord complications of thoracoabdominal aneurysm surgery

BACKGROUND

Although rare, paralysis secondary to spinal cord ischaemia after aortic aneurysm surgery is a devastating complication. Many papers have been published on this topic but without a clear consensus on the best way of minimizing the problem. Recent articles have included advanced pharmacological approaches and the literature has been reviewed in light of these.

METHODS

Relevant papers were identified by an extensive text word search of the Medline database and a review of quoted articles.

RESULTS

Spinal cord complications are commoner after the repair of Crawford type II aneurysms than less extensive aneurysms. The presence of dissection, rupture and prolonged clamp times are associated with an increased incidence. About a quarter of all cord problems develop over 24 h after surgery and this may be due to a reperfusion type injury, although the exact mechanisms are by no means clear.

CONCLUSION

A combination of rapid surgery, left heart bypass for the repair of more extensive aneurysms, free spinal drainage and the avoidance of postoperative hypoxia and hypotension help to minimize spinal cord ischaemia. No pharmacological agent has yet been shown conclusively to improve outcome in the clinical setting.

Isoprostanes: free radical-generated prostaglandins with constrictor effects on cerebral arterioles

BACKGROUND AND PURPOSE

Isoprostanes are generated by cyclooxygenase-independent free radical attack of arachidonic acid and are potent constrictors of the peripheral vasculature. Traumatic brain injury stimulates oxygen radical production and is associated with cerebral blood flow reduction. However, no specific vasoconstrictor has been identified as the cause of posttraumatic blood flow reduction. The purpose of this study was to determine whether isoprostanes constrict cerebral arterioles.

METHODS

The effects of 10(-9) to 10(-5) mol/L 8-iso-prostaglandin F2 alpha (8-iso-PGF2 alpha), 8-iso-prostaglandin E2 (8-iso-PGE2), and prostaglandin F2 alpha (PGF2 alpha) on pial arteriolar diameter were measured in anesthetized rats using a closed cranial window and in vivo microscopy.

RESULTS

All prostanoids produced vasoconstriction. Of these, 8-iso-PGF2 alpha produced the greatest vasoconstriction (34% +/- 2), followed by 8-iso-PGE2 (25% +/- 4) and PGF2 alpha (20% +/- 2). After six cerebrospinal fluid washouts of the cranial window, both 8-iso-PGF2 alpha- and 8-iso-PGE2-treated vessels remained slightly constricted, whereas the PGF2 alpha-treated vessels returned to control diameter. Coapplication of the semiselective thromboxane A2/prostaglandin H2 receptor antagonist SQ29548 completely blocked the vasoconstriction induced by 8-iso-PGF2 alpha and 8-iso-PGE2.

CONCLUSIONS

Isoprostanes are potent constrictors of cerebral arterioles and appear to act at a receptor that is similar to the thromboxane A2/prostaglandin H2 receptor. Isoprostanes may play a role in the reduction of cerebral blood flow that occurs after brain injury and subsequent oxygen radical production.

Perivascular coating with fibrin glue of cerebral arteries in patients with aneurysmal subarachnoid hemorrhage; incidence of chronic hydrocephalus

The incidence of chronic hydrocephalus was studied in 39 patients with subarachnoid hemorrhage, who underwent perivascular coating with fibrin glue of cerebral arteries after clipping of aneurysm. A use was made of this procedure in order to prevent vasospasm by keeping the main cerebral arteries away from direct contact with subarachnoid clots. Most cases in this series belonged to group 3 of Fisher's CT grade (33/39, 84.6%). As a result, despite the high CT grade, the incidence of chronic hydrocephalus was as low as 17.9% (7/39), almost in agreement with those of the previous literature. In conclusion, (1) coating with fibrin glue did not increase the incidence of chronic hydrocephalus and (2) intrathecal application of fibrin glue is a promising method in the field of clinical neurosurgery.