Ruptured intracranial aneurysms. Case morbidity and mortality

The Role of Computed Tomographic Angiography in Predicting the Development of Vasospasm Following Ruptured Intracranial Aneurysm Microsurgery

Introduction Following subarachnoid hemorrhage, cerebral vasospasm is the primary cause of morbidity and death. The aim of this study is to predict the development of vasospasm by detecting changes in vessel diameter after surgery using computed tomography angiography. Methods We retrospectively evaluated the patients who underwent aneurysm clipping due to a bleeding aneurysm between 2019-2022. Age, gender, location, subarachnoid hemorrhage grades, development of perioperative rupture, and temporary clip use were examined. Preoperative and postoperative diameters of the internal carotid artery, A1-A2, and M1-M2 were measured. Radiological and clinical vasospasm development in the postoperative period was also documented. Results The aneurysm localizations of the 100 patients (mean age: 50.38±13.04 years) were anterior cerebral artery in 50 patients, internal carotid artery in 37 patients, and middle cerebral artery in 30 patients. In the postoperative follow-up, radiological vasospasm was apparent in 41 patients. The changes in arterial diameter reveal a statistically significant decrease in the internal carotid artery, M1-M2, and A1-A2 artery diameters on the operated side compared to the contralateral side (p<0.001). Based on the receiver operating characteristic (ROC) analysis, the most likely change in arterial diameter on the operated side to indicate the presence of vasospasm was calculated from the available data, where the decrease in total arterial diameter was 13.7%. Conclusion Vasospasm remains one of the significant causes of morbidity and mortality post subarachnoid hemorrhage. While there have been advances in imaging modalities, predicting which patients will develop vasospasm has remained elusive. Our research attempts to provide a quantifiable metric (13.7% decrease in vessel diameter) that can be an early predictor of this complication.

Unruptured cerebral aneurysm risk stratification: Background, current research, and future directions in aneurysm assessment

Background:

The optimal management of unruptured cerebral aneurysms is widely debated in the medical field. Rapid technology advances, evolving understanding of underlying pathophysiology, and shifting practice patterns have made the cerebrovascular field particularly dynamic in recent years. Despite progress, there remains a dearth of large randomized studies to help guide the management of these controversial patients.

Methods:

We review the existing literature on the natural history of unruptured cerebral aneurysms and highlight ongoing research aimed at improving our ability to stratify risk in these patients.

Results:

Landmark natural history studies demonstrated the significance of size, location, and other risk factors for aneurysm rupture, but prior studies have significant limitations. We have begun to understand the underlying pathophysiology behind aneurysm formation and rupture and are now applying new tools such as flow dynamics simulations and machine learning to individualize rupture risk stratification.

Conclusion:

Prior studies have identified several key risk factors for aneurysmal rupture, but have limitations. New technology and research methods have enabled us to better understanding individual rupture risk for patients with unruptured cerebral aneurysms.

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.

Acute postoperative neurological deterioration associated with surgery for ruptured intracranial aneurysm: incidence, predictors, and outcomes

OBJECT

Subarachnoid hemorrhage (SAH) results in significant morbidity and mortality, even among patients who reach medical attention in good neurological condition. Many patients have neurological decline in the perioperative period, which contributes to long-term outcomes. The focus of this study is to characterize the incidence of, characteristics predictive of, and outcomes associated with acute postoperative neurological deterioration in patients undergoing surgery for ruptured intracranial aneurysm.

METHODS

The Intraoperative Hypothermia for Aneurysm Surgery Trial (IHAST) was a multicenter randomized clinical trial that enrolled 1001 patients and assesssed the efficacy of hypothermia as neuroprotection during surgery to secure a ruptured intracranial aneurysm. All patients had a radiographically confirmed SAH, were classified as World Federation of Neurosurgical Societies (WFNS) Grade I-III immediately prior to surgery, and underwent surgery to secure the ruptured aneurysm within 14 days of SAH. Neurological assessment with the National Institutes of Health Stroke Scale (NIHSS) was performed preoperatively, at 24 and 72 hours postoperatively, and at time of discharge. The primary outcome variable was a dichotomized scoring based on an IHAST version of the Glasgow Outcome Scale (GOS) in which a score of 1 represents a good outcome and a score > 1 a poor outcome, as assessed at 90-days' follow-up. Data from IHAST were analyzed for occurrence of a postoperative neurological deterioration. Preoperative and intraoperative variables were assessed for associations with occurrence of postoperative neurological deterioration. Differences in baseline, intraoperative, and postoperative variables and in outcomes between patients with and without postoperative neurological deterioration were compared with Fisher exact tests. The Wilcoxon rank-sum test was used to compare variables reported as means. Multiple logistic regression was used to adjust for covariates associated with occurrence of postoperative deficit.

RESULTS

Acute postoperative neurological deterioration was observed in 42.6% of the patients. New focal motor deficit accounted for 65% of postoperative neurological deterioration, while 60% was accounted for using the NIHSS total score change and 51% by Glasgow Coma Scale score change. Factors significantly associated with occurrence of postoperative neurological deterioration included: age, Fisher grade on admission, occurrence of a procedure prior to aneurysm surgery (ventriculostomy), timing of surgery, systolic blood pressure during surgery, ST segment depression during surgery, history of abnormality in cardiac valve function, use of intentional hypotension during surgery, duration of anterior cerebral artery occlusion, intraoperative blood loss, and difficulty of aneurysm exposure. Of the 426 patients with postoperative neurological deterioration at 24 hours after surgery, only 46.2% had a good outcome (GOS score of 1) at 3 months, while 77.7% of those without postoperative neurological deterioration at 24 hours had a good outcome (p < 0.05).

CONCLUSIONS

Neurological injury incurred perioperatively or in the acute postoperative period accounts for a large percentage of poor outcomes in patients with good admission WFNS grades undergoing surgery for aneurysmal SAH. Avoiding surgical factors associated with postoperative neurological deterioration and directing investigative efforts at developing improved neuroprotection for use in aneurysm surgery may significantly improve long-term neurological outcomes in patients with SAH.

Surgical treatment of anterior circulation aneurysms

The purpose of this paper is to present the results, assessed by an independent observer, of surgical treatment of 428 consecutive patients harbouring aneurysms of the anterior circulation, together with a review of relevant anatomy and operative strategy. At follow-up (mean 5.6 years) 89.3% lived at home and were independent, 5.1% lived at home but needed some kind of assistance, 2.0% lived in institution, whereas information was unavailable in 3.6% of living patients. Two hundred and fifty-three patients (64.5%) had unchanged employment status, 0.3% worked in sheltered environment, whereas 30.9% went out of work due to their subarachnoid hemorrhage (SAH). Information about employment status was unavailable in 4.3%. For aneurysms of the internal carotid, anterior communicating and middle cerebral artery, respectively, mortality was 3.2, 3.9 and 5.6%, whereas 92.0, 88.1 and 89.0% of surviving patients lived at home and were independent and 67.0, 63.6 and 63.0% had unchanged employment status. Three-months mortality of all causes was 4.2%. In the postoperative period 53 (12.4%) patients developed clinical signs of vasospasms, 6 (1.4%) had cardiac infarction, 4 (0.9%) lung oedema, 4 (0.9%) deep vein thrombosis, and 7 patients (1.6%) infection. During the follow-up period shunt-dependent hydrocephalus developed in 4.2% and 0.2% had a subsequent SAH from the same aneurysm. Forty-three patients were on anticonvulsive therapy.

Outcome of 337 intracranial aneurysms patients operated in a public hospital

Many recent series of surgery for intracranial aneurysms have been based on experience of developed countries with great resources and a state of art health care. The purpose of the current study is to correlate the outcome of patients operated for intracranial aneurysms, reported from intensive high technology neurosurgical centers with the results of low technology, environment, where we practice. Between January 1986 and December 1996, 337 patients with intracranial aneurysms were operated on at the Servidores do Estado Hospital. We retrospectively reviewed the medical and radiologic records and compared the outcome of this group with other series derived from developed countries. The overall mortality of this series was 6.9%. Of the 313 good grades surgical patients, the mortality was 4.7% and the successful results were obtained in 88.8% individuals. We conclude that patients harboring intracranial aneurysms can be satisfactory handled in less developed nations, if a meticulous intraoperative technique is employed, even though sophisticated technology and equipment are not available.

Effect of transluminal angioplasty on cerebral blood flow in the management of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage

In this study the authors have examined the effects of transluminal angioplasty on cerebral blood flow (CBF) in the management of intractable vasospasm following aneurysmal subarachnoid hemorrhage (SAH). Fourteen consecutively enrolled patients underwent attempted angioplasty with or without intraarterial infusion of papaverine. Twelve patients underwent pre- and postangioplasty xenon-enhanced computerized tomography (Xe-CT) scanning to measure regional CBF in 55 to 65 regions of interest (ROIs) per patient. Angioplasty was possible in 13 (93%) of 14 patients, with angiographically demonstrated improvement in all 13. Twelve (92%) of the 13 patients were neurologically improved following angioplasty; seven (58%) of the 12 patients who improved had a complete reversal of all delayed ischemic deficits. Angioplasty significantly decreased the mean number of ROIs at risk (11.4 ROIs pre- and 0.9 ROIs postangioplasty) (p < 0.00005, t-test). All patients had a reduction in the number of ROIs at risk after angioplasty; six (50%) of 12 no longer had any ROIs remaining at risk after angioplasty. Angioplasty significantly increased the mean CBF within at-risk ROIs (13 ml/100 g/minute pre- and 44 ml/100 g/minute postangioplasty) (p < 0.00005, t-test). All patients experienced an improvement in mean CBF in at-risk ROIs after angioplasty, with the mean CBF improving to above 20 ml/100 g/minute in all cases. No differences in the degree of improvement were found in patients who received intraarterial papaverine compared with those who did not. In the majority of patients with refractory vasospasm following SAH, angioplasty effectively dilated spastic arteries, reversed delayed neurological deficits, and significantly improved CBF in areas of brain at risk of infarction.

Study on early re-rupture of intracranial aneurysms

The prognosis of patients with early re-ruptured intracranial aneurysms is discouraging. We compared the data on patients suffering re-rupture before the onset of late vasospasm (Early-Re) with those suffering rebleeding thereafter (Late-Re). The operability in the Early-Re group was lower (p < 0.05) and the outcome less satisfactory than that of Late-Re group. Of the Early-Re patients, 83% had a re-rupture within 24 hours of the initial subarachnoid haemorrhage; moreover 46% of these experienced rebleeding within three hours of the initial bleeding. Cases in the Early-Re group tended to belong to Hunt-Hess grade III or IV on admission, of wide spread subarachnoid haemorrhage on CT and of "bump" type aneurysms on angiograms. Based on our experience we propose that early re-rupture may be attributable to the following factors: a gradual and progressive thinning of the wall of bump type aneurysms results in such a large laceration through the fundus of the aneurysm. Re-rupture may occur within a short period after the first rupture because the fibrin net covering the wide laceration cannot tolerate the slight increase in internal pressure within the aneurysmal dome. Therefore, in the patients of Hunt-Hess grade III or IV, conventional angiography, tight holding during CT examination and lumbar puncture, should be avoided during the first three hours after the first bleed. Although early direct operations on patients with high Hunt-Hess grades tend to produce an unsatisfactory outcome, we cannot help these patients with Early-Re without surgical treatment. Not only early direct operation but also first conservative treatment to control systolic blood pressure are very important in patients with Early-Re.

A clinical study of the relationship of timing to outcome of surgery for ruptured cerebral aneurysms. A retrospective analysis of 1622 cases

Between 1980 and 1987, 1622 patients with angiographically verified ruptured cerebral aneurysms were admitted within 7 days after subarachnoid hemorrhage. A retrospective analysis evaluated both the timing of surgery in operative patients and the status of nonsurgical patients. The patients' clinical grade according to the Hunt and Hess classification was assessed at admission, and a comparative analysis of outcome was carried out for each grade in relation to time of surgery: those operated on from Day 0 to 3 and those undergoing surgery on Day 4 or later. Among nonsurgical cases, fatal rebleeding occurred in 105 cases and fatal vasospasm in 69 cases. These nonsurgical cases were divided into one of two groups, either an early- or a late-management group, and the outcome of each group was analyzed by clinical grade. The mortality rates in the early-surgery groups were higher than in the late-surgery groups, especially in Grade V, in which the rate was significantly different. However, with the 174 nonsurgical patients included in these management results, marked differences in mortality rates disappeared except in Grade V, which failed to show statistical significance. A higher rate of good recovery among Grade III patients receiving early surgery shifted significantly in the early-management group. The results suggest that the timing of surgery in clinical Grade I or II patients is not a major factor; however, early surgery appears to be beneficial in Grade III and IV patients. The incidence of rebleeding in the early- and late-management groups was 2.7% and 9.5%, respectively.

Total overall management and surgical outcome after aneurysmal subarachnoid haemorrhage in a defined population

It was possible from a geographically well-defined region to detect all patients sustaining an aneurysmal subarachnoid haemorrhage. Different outcomes were measured and compared with other published series. Twenty-one per cent of all our patients at risk were never seen by a neurosurgeon. By adding further 20% of dead patients to the management series a total overall outcome, i.e. from all 'patients at risk', could be calculated, making comparison between different series easier. Favourable outcomes in the three groups (total overall, total management and surgical) as measured with the Glasgow Outcome Scale at 12 months were 46, 58 and 69%, respectively, in this series. In a super selected group such as good-grade patients (Hunt and Hess I-II) at surgery favourable results were seen in 87% of the patients at 6 months follow-up. The favourable outcome in the total overall, total management and surgical groups increased between 6 and 12 months follow-up by 1, 1 and 2%, respectively, as compared to 4, 5 and 6%, respectively, between discharge and 6 months follow-up. The time of follow-up to measure outcome should not be shorter than 6 months in aneurysm cases. It is emphasized that all patients drop-outs from the initial 'patient at risk' should be identified.

The International Cooperative Study on the Timing of Aneurysm Surgery. Part 2: Surgical results

A prospective, observational clinical trial was conducted by the International Cooperative Study on the Timing of Aneurysm Surgery to determine the best time in relation to the hemorrhage for surgical treatment of ruptured intracranial aneurysms. Sixty-eight centers contributed 3521 patients in a 2 1/2-year period beginning in December, 1980. Analysis by a prespecified "planned" surgery interval demonstrated that there was no difference in early (0 to 3 days after the bleed) or late surgery (11 to 14 days). Outcome was worse if surgery was performed in the 7 to 10-day post-bleed interval. Surgical results were better for patients operated on after 10 days. Patients alert on admission fared best; however, alert patients had a mortality rate of 10% to 12% when undergoing surgery prior to Day 11 compared with 3% to 5% when surgery was performed after Day 10. Patients drowsy on admission had a 21% to 25% mortality rate when operated on up to Day 11 and 7% to 10% with surgery thereafter. Overall, early surgery was neither more hazardous nor beneficial than delayed surgery. The postoperative risk following early surgery is equivalent to the risk of rebleeding and vasospasm in patients waiting for delayed surgery.

The International Cooperative Study on the Timing of Aneurysm Surgery. Part 1: Overall management results

The International Cooperative Study on the Timing of Aneurysm Surgery evaluated the results of surgical and medical management in 3521 patients between December, 1980, and July, 1983. At admission, 75% of patients were in good neurological condition and surgery was performed in 83%. At the 6-month evaluation, 26% of the patients had died and 58% exhibited a complete recovery. Vasospasm and rebleeding were the leading causes of morbidity and mortality in addition to the initial bleed. Predictors for mortality included the patient's decreased level of consciousness and increased age, thickness of the subarachnoid hemorrhage clot on computerized tomography, elevated blood pressure, preexisting medical illnesses, and basilar aneurysms. The results presented here document the status of management in the 1980's.

Chronic cerebral blood flow changes following experimental subarachnoid hemorrhage in rats

Experimental subarachnoid hemorrhage was induced in 52 adult male Wistar rats by microsurgical transclival basilar artery puncture. Telencephalic blood flow measured in 24 rats with subarachnoid hemorrhage was compared with that in 23 sham-operated rats and 10 unoperated control rats using the [14C]butanol indicator fractionation technique. Telencephalic blood flow was significantly less in the rats with subarachnoid hemorrhage than in the sham-operated rats 3 (78.7 +/- 6.9 [n = 7] and 112.0 +/- 8.5 [n = 8] ml/100 g/min, respectively; p less than 0.01), 7 (74.9 +/- 5.1 [n = 9] and 112.6 +/- 4.6 [n = 8] ml/100 g/min, p less than 0.001), and 14 (81.9 +/- 6.0 [n = 8] and 104.1 +/- 5.4 [n = 7] ml/100 g/min, p less than 0.01) days after surgery. Telencephalic blood flow in unoperated controls (114.7 +/- 4.9 ml/100 g/min) did not differ significantly from sham-operated rats. Clinically, the 52 rats with subarachnoid hemorrhage were indistinguishable from 32 sham-operated rats. Postmortem examinations in 10 rats used in a preliminary investigation demonstrated significant blood clot in the basal cisterns 2 hours after basilar artery puncture. Intracranial pressure was slightly elevated (2.3 mm Hg over baseline) 30 minutes after the hemorrhage (n = 7), but when measured 3 (n = 3) or 7 (n = 3) days after surgery it had returned to baseline. Histologic examination of the brains from 10 rats subjected to subarachnoid hemorrhage 7 (n = 5) or 14 (n = 5) days before sacrifice revealed no evidence of cerebral ischemia or vasculopathic changes in the cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Subarachnoid haemorrhage of unknown aetiology

The authors review the literature on subarachnoid haemorrhage of unknown aetiology (SAHUE) and analyze a personal series of 212 patients diagnosed as SAHUE. These patients represent 30% of all cases of primary SAH admitted over a 14.5 year period. The age, sex, antecedents and initial clinical presentation of patients with SAHUE were indistinguishable from those of patients with subarachnoid haemorrhage due to ruptured aneurysm (SAHRA). However, the present series of SAHUE compare favourably with both a personal and a previously reported series of SAHRA insofar as clinical grade on admission (94% of patients in grades I-II of Botterell), presence of blood on CT (51%), vasospasm (5%), ischaemic deficits (3.3%), persistent hydrocephalus (3.5%), rebleeding (6%) and fatal result (3.9%) are concerned. The amount of blood on CT scan in our patients with SAHUE was associated with a significantly higher incidence of brain ischaemia and hydrocephalus but did not correlate with the Botterell grade on admission or final outcome, which were good in the majority of cases regardless of the presence or not of visible cisternal haemorrhage. The results of the present series confirm that the final prognosis of patients with primary SAH showing normal four-vessel cerebral angiography is essentially favourable.

Blood-arterial wall barrier disruption to various sized tracers following subarachnoid haemorrhage

Disruption of the blood-arterial wall barrier in the major cerebral arteries occurs following subarachnoid haemorrhage (SAH) and may be related to the pathogenesis of cerebral vasospasm. Using FITC dextrans of various sizes, the present study was undertaken to determine if the barrier disruption shortly after SAH occurs equally to various sized tracers. Forty-two Sprague-Dawley rats were divided into 5 groups. Four groups were injected with FITC-dextrans of differing molecular weights (MW): FD4 (MW = 4,080), FD 40 (MW = 40,500), FD 70 (MW = 71,400), and FD 150 (MW = 156,900). One group was injected with horseradish peroxidase (HRP: MW = 40,000). Each group was further divided into two subgroups: with or without SAH. SAH was induced by injecting arterial blood into the cisterna magna. To assess the integrity of the blood-arterial wall barrier by transmission electron microscope, the tracers were intravenously injected prior to sacrificing the animals. The groups without SAH showed no permeability of tracers into the subendothelial spaces of the basilar arteries. In contrast, with the exception of FD 150, FITC-dextrans (FD 4, FD 40, FD 70) were noticed in the subendothelial spaces. The distribution of FITC-dextrans in the elastic lamina was similar to that of HRP. These results suggest that barrier disruption occurs with a wide range of molecular sizes of FITC-dextrans, although there seems to be some limitation to the permeation of the larger molecules. The present study suggests that the mechanism of barrier disruption of the major cerebral arteries in the acute stage following SAH may be vesicular rather than by separation of tight junctions.

Rebleeding, ischaemia and hydrocephalus following anti-fibrinolytic treatment for ruptured cerebral aneurysms: a retrospective clinical study

350 patients with subarachnoid haemorrhage from aneurysmal rupture--admitted in the years 1966-1983--were selected for a retrospective controlled study on the efficacy of antifibrinolytic therapy (AFT). Patients treated with antifibrinolytics were divided into two groups, according to the day of hospital admission and onset of therapy, respectively between 0 and 3 days (SG 1) and between 4 and 7 days from SAH (SG 2); treated patients (260 cases) received i.v. tranexamic acid (6 gr/day) for at least two weeks. Patients admitted before 1974, not receiving antifibrinolytics (90 cases), were selected as controls and divided into two groups (CG 1 and CG 2), according to the day of admission. In the first study group (admission 0-3 days) the rebleeding rate within 2 weeks was 9% versus 23% in controls (p less than 0.01). The incidence of rebleeding within 3 and 4 weeks was also significantly lower (p less than 0.05) than in controls. No significant difference was observed in the rebleeding rate in treated and untreated patients with late admission (4-7 days). Mortality from rebleeding was 16% in the first study group versus 17% in controls; in the second study group the figure was 6% versus 8% in controls. Seventy-five cases of ischaemic disorders (29%) were registered in treated patients versus 13 cases in controls (14%; p less than 0.01). Thirty-seven patients receiving AFT (14%) developed significant ventricular dilatation requiring shunt insertion, versus one patient in the control groups (1%; p less than 0.001). Final outcome was similar in the 4 groups. In conclusion--according to our data--AFT modifies the behaviour of rebleeding and the patients' course, although it does not modify the outcome after SAH. Clinical use of antifibrinolytic therapy appears still justified in those patients who cannot be operated on in the acute stage after SAH, provided that an associated anti-ischaemic therapy is undertaken.

Aneurysmal subarachnoid hemorrhage in Izumo City and Shimane Prefecture of Japan. Outcome

The overall outcome of patients with aneurysmal subarachnoid hemorrhage was investigated in Izumo City and Shimane Prefecture. Of the patients from Izumo City, the clinical grade on admission was Grade I or II in 41% and Grade IV or V in 31%. Of those from Shimane Prefecture, 49% were graded as Grade I or II and 24% as Grade IV or V. The overall mortality rates 1 year after subarachnoid hemorrhage were 46% for Izumo City and 35% for Shimane Prefecture, while the surgical mortality rates were 18 and 15%, respectively. The mortality rates were particularly high among the elderly over the age of 70 years and among unoperated cases. The leading cause of death in these cases was the effect of aneurysm rupture itself, followed by rebleeding and vasospasm. The 5-year survival probabilities according to life table analysis were 50% for Izumo City and 59% for Shimane Prefecture, and a significant difference was observed in survival curves between Izumo City and Shimane Prefecture. It is concluded that the smaller the community studied, the less favorable the overall outcome, mainly because of poorer clinical conditions on admission.

Recurrent aneurysmal subarachnoid haemorrhage: incidence, timing and effects. A re-appraisal in a surgical series

A series of 510 patients with proven aneurysmal subarachnoid haemorrhage (SAH) is reported. The incidence of recurrent haemorrhage during the period awaiting surgery was 13.7%. There was no significant difference in incidence between good and poor grade patients. Following rebleeding there was an immediate mortality of 34% in good grade patients and 52% in poor grade patients. In the long term only 44.4% of good grade and 8% of poor grade patients made a good recovery following a second bleed as compared to 70.6% and 52.8% respectively for those who did not rehaemorrhage.

Aneurysmal subarachnoid hemorrhage. Complications and outcome in a hospital population

We describe total management results in a prospective series of 264 patients with aneurysmal subarachnoid hemorrhage (SAH) admitted to a neurologic unit. Referrals were actively solicited from general physicians as well as neurologists in the area. The diagnosis was based on computed tomography (CT). Secondary deteriorations were analyzed clinically and with serial CT scanning. Outcome was assessed 3 months after SAH. There were no relevant differences between the analyses of patients with and without an aneurysm confirmed by angiography or autopsy. One third of the patients either died within 1 day (12%) or remained in a poor clinical condition that precluded surgery (22%). One third were in good clinical condition, but contraindications to surgery were judged present or serious complications occurred before surgery could be performed. One third of all patients underwent surgery. Overall mortality in our series was 52%; only 26% made a good recovery. The risk of rebleeding was not related to the patients' initial clinical condition, but all other intracranial complications occurred significantly more often in patients graded poor compared with patients in good clinical condition. The most important causes of death and severe disability were hemorrhage (16%), recurrent hemorrhage (18%), and delayed cerebral ischemia (15%). The most important surgical complication was delayed deterioration caused by ischemia (20% of operated patients). We estimated that recognition of 'warning leaks,' surgery in patients over 65, and improvement of our surgical technique could decrease mortality from 52% to approximately 41%.

Is there a role for heparin in the management of complications of subarachnoid hemorrhage?

Proven effective therapy to prevent ischemic deficits and other complications after subarachnoid hemorrhage is lacking despite extensive research efforts. A literature review documented both clinical and experimental evidence suggesting that heparin may be effective in preventing ischemic deficits after subarachnoid hemorrhage by reversing vasospasm, improving blood flow through narrowed vessels, and preventing the development of a proliferative angiopathy. Additional evidence suggests that heparinization of the cerebrospinal fluid following subarachnoid hemorrhage may prevent the development of hydrocephalus. In the only clinical trial using heparin after subarachnoid hemorrhage, the incidence of rebleeding in the heparinized patients was no higher than in the control group. We conclude that the existing preliminary data concerning a role for heparin in the management of the complications of subarachnoid hemorrhage is promising, but further controlled studies are needed prior to clinical application.

Effect of subarachnoid hemorrhage on endothelium-dependent vasodilation

The effect of subarachnoid hemorrhage (SAH) on endothelium-dependent vasodilation of the isolated rabbit basilar artery was examined using an isometric tension recording method. The SAH was induced by injecting 5 ml of fresh arterial blood into the cisterna magna. Sixty-two rabbits were separated into four groups according to the timing of sacrifice: control rabbits, and operated rabbits sacrificed on Days 2, 4, and 6 after SAH. Acetylcholine (ACh) (10(-7) M to 10(-4) M) and adenosine triphosphate (ATP) (10(-7) M to 10(-4) M) were used to evoke dose-dependent vasodilation of isolated arterial rings previously contracted by 10(-6) M serotonin (5-HT). There were no significant differences in the vasodilatory response to ACh among these four groups. Relaxation to approximately 84% of the initial contractile tone occurred with 10(-4) M ACh. On the other hand, the vasodilatory response to ATP was suppressed in the animals sacrificed 2 days after SAH; the relaxation of this group was approximately 52% at 10(-4) M ATP, compared to a relaxation of 87% observed in the other groups of animals. One of the major causes of the impairment of endothelium-dependent vasodilation seems to be an inhibition of the production of endothelium-derived relaxing factor by endothelial cells. After the relaxation studies, the dose-response curves for 5-HT were obtained. Serotonin caused significantly more contraction in the animals sacrificed 2 days after SAH than in the other groups. The present experiments suggest that impairment of the endothelium-dependent vasodilation following SAH, together with the potentiation of the contractile response to vasoactive agents in cerebral arteries, may play an important role in the pathogenesis of vasospasm.

Subarachnoid hemorrhage: frequency and severity of cardiac arrhythmias. A survey of 70 cases studied in the acute phase

The frequency and severity of cardiac arrhythmias were studied in 70 patients with spontaneous subarachnoid hemorrhage investigated prospectively with 24-hour Holter monitoring. Patients were less than 70 years old and without clinical and/or ECG signs of previous heart disease; Holter monitoring was initiated within 48 hours of subarachnoid hemorrhage. Arrhythmias were detected in 64 of the 70 patients (91%). Twenty-nine of the 70 patients (41%) showed serious cardiac arrhythmias; malignant ventricular arrhythmias, i.e., torsade de pointe and ventricular flutter or fibrillation, occurred in 3 cases. Serious ventricular arrhythmias were associated with QTc prolongation and hypokalemia. No correlation was found between the frequency and severity of cardiac arrhythmias and the neurologic condition, the site and extent of intracranial blood on computed tomography scan, or the location of ruptured malformation. The extremely high incidence of cardiac arrhythmias, sometimes serious, in the acute period after subarachnoid hemorrhage and the absence of clinical and radiologic predictors make systematic continuous ECG monitoring compulsory to improve the overall results of subarachnoid hemorrhage, irrespective of early or delayed surgical treatment.

Plasticity of the brain in respect of functional restoration after subarachnoid haemorrhage

Subarachnoid haemorrhage caused by aneurysmal rupture constitutes a great impact on the brain and on the intracranial content as a whole, with emphasis on the subarachnoid spaces and arteries. The rupture is followed by a wide range of pathological alterations in the neural function and an outcome varying from neglected signs subsiding in a few days to immediate death. Two main factors seem to influence the different events after subarachnoid bleeding. One is the rupture itself which can be extremely variable in severity and in its immediate as well as late consequences. The other is the ability of all parts of the intracranial content to recover. In order to understand either of both the other should also be looked at and both have to be dealt with if we are to treat patients with an aneurysmal rupture properly. For this reason a grading of rupture will be given in respect of some characteristic events in the light of neural restoration. Clearing of CSF, resolution of brain oedema, restoration of impaired CBF, absorption of cisternal and parenchymal haematoma are all of importance. The majority of lesions which developed after the rupture are not fatal or irreversible and even the neural tissue destroyed by the impact or late ischaemia can be functionally replaced. Possible methods of treatment for attaining this functional restoration will be discussed.

Age as a prognostic factor after intracranial aneurysm rupture

1,076 patients with ruptured aneurysms admitted to neurosurgical units in Denmark over a period of 5 years were followed up for 2 years. The outcome as regards survival and normality of mental state was assessed in relation to age, clinical grade, and whether or not surgery was performed. For all ages and grades operated patients did better than those not operated on. Age seemed to have no bearing on outcome except for operated on good condition patients (grades 1-3) under the age of 40 years, who were significantly more likely to have a normal mental outcome than other groups.

Antifibrinolytic agents in subarachnoid haemorrhage

For many years clinicians have used antifibrinolytic agents to try to reduce rebleeding after subarachnoid haemorrhage. Early studies of their effectiveness produced conflicting results. This paper re-evaluates the available trials and considers benefits in the light of potential complications. Present evidence conclusively demonstrates that epsilon-aminocaproic acid and tranexamic acid administered in standard dosage, reduce the risk of rebleeding but, as a result of an increased incidence of ischaemic complications, do not benefit patients' outcome.

Observations on the perioperative management of aneurysmal subarachnoid hemorrhage

Thirty-two patients with aneurysmal subarachnoid hemorrhage (SAH) were managed according to a protocol based on pain control and hemodynamic manipulation, monitored by an arterial line and Swan-Ganz catheter. Hemodynamic parameters were adjusted to four clinical situations. 1) For the unoperated patient with no neurological deficit, the regimen aims to maintain pulmonary wedge pressure (PWP) at 10 to 12 mm Hg, and the cardiac index (CI) and blood pressure (BP) at normal levels. 2) For the unoperated patient presenting with or developing neurological deficit, the PWP is increased until the deficit is reversed or the CI falls; the CI is high, and the BP normal. 3) For the postoperative patient with no neurological deficit, the PWP is maintained at 12 to 14 mm Hg, the CI is a high normal, and the BP is normal. 4) For the postoperative patient developing neurological deficit but showing no surgical complication on the computerized tomography scan, the PWP is increased until the deficit is reversed or the CI falls; the CI is high and the BP is increased with vasopressors if necessary. Fourteen patients developed neurological deficits either preoperatively, postoperatively, or both. Neurological deficits were repeatedly reversed by increasing the PWP, as measured hourly. In several patients an optimal wedge pressure was determined, below which deficits would reappear. In one patient whose neurological deficit was reversed on several occasions by increasing the PWP, the optimal PWP rose after each episode until it reached 22 mm Hg. Detailed event-related analysis of these patients' course illustrates these phenomena well. The optimal PWP varied from patient to patient, but ranged most frequently from 14 to 16 mm Hg. Meticulous monitoring of the patients' neurological status coupled with prompt correction of low PWP (assuming an adequate CI) has proven to be an effective way to prevent and reverse neurological deficits following aneurysmal SAH.

Ruptured intracranial aneurysms: the overall effect of treatment and the influence of patient selection and data presentation on the reported outcome

An attempt is made to assess the overall impact of current treatment of ruptured intracranial aneurysms, based on the outcome in 200 consecutive patients, unselected in that they were transferred to neurosurgical care as soon as they were referred, regardless of clinical condition. Overall mortality at 1 year was 35.5%. It is estimated that at the present time treatment improves the one-year survival of patients who reach the primary care hospital by no more than 12-15%. In assessing the apparent benefits of treatment, it is easy to overlook the effects of patient selection and the way in which data are presented. Other admission policies in line with current practice but involving greater selectivity and delay in transfer, could have reduced the one-year mortality of this series of patients to 16.1%, by excluding from neurosurgical care patients who were in a poor condition or about to deteriorate. The outcome data in this series could be presented in different ways so as to represent the surgical mortality as ranging between 13.8% and 3.3%.

Subarachnoid hemorrhage: epidemiology, diagnosis, management, and outcome

A population-based study of primary subarachnoid hemorrhage in Auckland (population 829,454), New Zealand, identified 180 cases in a two-year period. This represented an age adjusted incidence rate of 10.5 and 18.3 per 100,000 for men and women respectively. Sixty-eight percent of all cases had a proven intracranial aneurysm or arteriovenous malformation, 15% had negative angiographic findings and in the remaining 17%, the presence or absence of a localized lesion was unknown since neither angiography nor autopsy were performed. Twenty-six patients (15%) died before hospitalization and a further 36 patients (20%) died within 48 hours of onset. Only 94 patients (53% of all patients registered) were fit enough to undergo angiography. A surgical operation was carried out on 60 of the 68 patients in whom an aneurysm was confirmed at angiography. The overall case fatality rate was 36% within the first 48 hours, 43% in the first week and 57% at both six months and one year. The high early case fatality rates are similar to those found in previous population-based studies, suggesting that despite the major advances to individual patients from technological advances, the potential contribution of hospital management to the reduction of subarachnoid haemorrhage mortality rates is likely to be limited.

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage is one of the most important causes of cerebral ischemia, and is the leading cause of death and disability after aneurysm rupture. There are two definitions of cerebral vasospasm: angiographic and clinical. Care must be exercised to be certain that it is clear which entity is being addressed. The diagnosis of the clinical syndrome is one of exclusion and can rarely be made with absolute certainty. The pathogenesis of cerebral vasospasm is poorly understood. Most current theories focus on the release of factors from the subarachnoid clot. More attention must be given to the role of endothelial damage and alterations in the blood-arterial wall barrier. The application of modern techniques for studying vascular smooth muscle which have been developed as a result of research in the areas of hypertension and atherosclerosis must be applied to the problem of cerebral vasospasm. A stress test to select patients with angiographic arterial narrowing who have adequate cerebral vascular reserve to undergo surgery should be developed. The optimal treatment of vasospasm awaits development of agents for blocking or inactivating spasmogenic substances or blocking arterial smooth muscle contraction. Rheological or hemodynamic manipulations to prevent or reverse ischemic consequences of vasospasm are relatively effective, but complicated and hazardous, and should be viewed principally as interim measures awaiting development of more specific therapies for the arterial narrowing.

Early cerebral blood flow and computerized tomography in predicting ischemia after cerebral aneurysm rupture

Cerebral blood flow (CBF) was measured during the 1st week of subarachnoid hemorrhage in 46 patients who were in a good clinical grade and had a proven ruptured intracranial aneurysm. The mean initial CBF in patients who developed cerebral ischemia was 42 ml/min-1/100 gm brain-1, which was significantly lower than in patients who did not develop cerebral ischemia (49 ml/min-1/100 gm brain-1). This reduced CBF was not secondary to raised intracranial pressure or angiographic spasm. Patients with a reduced CBF (less than 50 ml/min-1/100 gm brain-1) and diffuse subarachnoid blood on computerized tomography had a very high incidence (78%) of cerebral ischemia, despite a good clinical grade at the time of measurement. Serial CBF measurements are of value in monitoring the evolution of cerebral vasospasm.

Cerebral vasospasm as a complication of aneurysmal subarachnoid hemorrhage: a brief review

Cerebral vasospasm is one of the most dreaded consequences of a ruptured intracranial aneurysm. Although exceptions may be found, the relationship between angiographic narrowing of cerebral arteries and deterioration of clinical status is supported by many authors. The cause of cerebral vasospasm still remains obscure. Several substances such as serotonin, prostaglandins, catecholamines appear to have a vasoconstrictive effect on the cerebral vessels. Recent evidence indicates that erythrocyte lysis within the subarachnoid spaces may play a major role in the genesis of delayed clinically relevant cerebral vasoconstriction following aneurysmal subarachnoid hemorrhage (SAH). The pathophysiology of brain ischemia following aneurysmal rupture, and the correlation between angiographic vasospasm, neurological condition, intracranial pressure (ICP) value, cerebral blood flow and CT findings are briefly discussed. It is concluded that, at present, blood volume expansion and/or induced hypertension, and pharmacological control of increased ICP provide the best basis for clinical management of the cerebral ischemic complications of SAH. Preoperative antifibrinolytic therapy and delayed surgical obliteration of the bleeding aneurysm, i.e. the policy at present most frequently adopted, are currently undergoing critical review in the light of the fact that antifibrinolytic therapy seems to be accompanied by a higher rate of ischemic SAH complications and vasospasm, whilst there are very recent suggestions that the results of early intracranial aneurysm surgery may be better than those of delayed surgery, if account is taken of the patients lost because of recurrent SAH or ischemia during the waiting period.

Aneurysmal subarachnoid hemorrhage--historical background from a Scandinavian horizon

The historical background of aneurysmal subarachnoid hemorrhage is depicted with emphasis in the Scandinavian contribution to improvements in the treatment. It is concluded that an aneurysmal subarachnoid hemorrhage with all certainty was the cause of death of the prospective King of Sweden, Charles August, in the year 1810. Despite advances in management and surgical treatment of this devastating disease the outcome in this important patient--which led to a new royal dynasty in Sweden--would certainly have turned out as fatal today as became the case 174 years ago.

Antifibrinolytic treatment in subarachnoid hemorrhage

We enrolled 479 patients with subarachnoid hemorrhage in a multicenter, randomized, double-blind, placebo-controlled trial to determine whether treatment with the antifibrinolytic agent tranexamic acid improves outcome by preventing rebleeding. At three months there was no statistical difference between the outcomes in the tranexamic acid group and the control group. Of the 173 patients who died, 84 had received tranexamic acid and 89 placebo (95 per cent confidence interval for the difference in mortality rate, -6 to 11 per cent). Similarly, when analysis was restricted to patients with an angiographically demonstrated aneurysm, there was no significant difference between the groups. This absence of effect was not due to a lack of antifibrinolytic action, since the rate of rebleeding was reduced from 24 per cent in the control group to 9 per cent in the tranexamic acid-treated group (chi-square = 18.07, P less than 0.001), but resulted from a concurrent increase in the incidence of ischemic complications (15 per cent in the control group and 24 per cent in the tranexamic acid group; chi-square = 8.07, P less than 0.01). We conclude that until some method can be found to minimize ischemic complications, tranexamic acid is of no benefit in patients with subarachnoid hemorrhage.

Cerebral vasospasm after subarachnoid hemorrhage

Chronic cerebral vasospasm remains the most important cause of subsequent morbidity in patients who survive the first 48 to 72 hours after a subarachnoid hemorrhage. Prolonged arterial narrowing compromises cerebral hemodynamics and results in cerebral ischemia. Among patients in whom symptomatic chronic cerebral vasospasm develops, almost half die or have a serious residual neurologic deficit. Present evidence indicates that sustained vessel narrowing results from structural changes within the arterial wall rather than from active contraction of vascular smooth muscle. The mechanism (or mechanisms) responsible for these changes is unknown, but damage from prolonged active arterial contraction, depression of vessel wall respiration, and an inflammatory response have all been proposed as explanations. Despite more than 30 years of intensive study, an effective treatment program for chronic cerebral vasospasm remains elusive. Recent therapeutic trials, however, based on efforts to interrupt the mechanisms responsible for these structural changes hold some promise.

Analysis of 223 ruptured intracranial aneurysms with special reference to rerupture

A review of 223 patients with ruptured intracranial aneurysms, including 46 with rerupture, showed that the operability rate was higher and the prognosis better in patients with one rupture. Rerupture cases with low Hunt--Hess grades (0--II) had no better prognosis than one-rupture cases of grade IV. The mean interval between first rupture and rerupture was 12 days. Aneurysms located in the vertebrobasilar system showed the highest rate of rerupture. Daughter and bled-shaped aneurysms had a greater tendency to rerupture. The incidence of rerupture was increased in patients with narrowly localized vasospasm and acute hydrocephalus. Time-course studies of factors of the coagulating and fibrinolytic system suggested their usefulness in predicting the occurrence of vasospasm, infarction, and rerupture and the prognosis of patients with ruptured intracranial aneurysms. Patients at high risk for rerupture of aneurysm should undergo early operation.

Prediction of cerebral vasospasm value of fibrinogen degradation products (FDP) in the cerebro-spinal fluid (CSF) for prediction of vasospasm following subarachnoid haemorrhage due to a ruptured aneurysm

In a new treatment regimen with antifibrinolytic drugs in patients with aneurysmal subarachnoid haemorrhages, we have systematically controlled the level of fibrinogen degradation products (FDP) in the cerebrospinal fluid (CSF). The frequency of severe vasospasm with clinical ischaemia has been compared with the patient's initial level of FDP. Fifty patients have been included in this study. (All in Hunt and Hess's grades I or II on their arrival.) Patients with a secondary deterioration unrelated to vasospasm were excluded. The FDP levels were measured in the first three days following the bleeding and we were informed of them at the end of the study. The diagnosis of severe vasospasm was confirmed by arteriography and computed tomography (CT) and it was named "severe" when accompanied with signs of clinical ischaemia. Twenty patients developed a severe vasospasm with clinical ischaemia. In these patients, the mean value of the initial FDP level was between 80 and 320 mcg/ml compared with 20 to 80 mcg/ml for those who had not developed clinical ischaemia (p = 0.0009). Furthermore, two different groups may be discriminated by their initial FDP level: FDP greater than 80 mcg/ml; n = 23, 65% severe vasospasm; FDP less than 80 mcg/ml; n = 27.8% no severe vasospasm (p less than 0.001). These results do not imply a direct role of FDP in pathophysiological mechanisms of vasospasm, but they suggest a relationship between the clot lysis and the appearance of vasospasm with clinical ischaemia. To our knowledge this is the first time that such a predictive role can be attributed to the initial FDP level in the prognosis of vasospasm.

An experimental study of the influence of antifibrinolytic therapy on post-subarachnoid-hemorrhagic cerebral vasospasm and hydrocephalus

The incidence and severity of cerebral vasospasm and hydrocephalus following induced subarachnoid hemorrhage in an experimental group of animals that subsequently received epsilon-aminocaproic acid was compared to that seen in a control group that received no antifibrinolytic therapy. No augmentation of either vasospasm or hydrocephalus could be attributed to the epsilon-aminocaproic acid in the treated as compared to the control group.

Correlation between angiographic vasospasm, hematoma, and ischemic brain damage following SAH

The correlation between angiographic vasospasm, hematoma, and ischemic brain damage was studied in 29 patients who died as a result of subarachnoid hemorrhage following rupture of a saccular aneurysm. None of these patients was treated surgically. A comprehensive neuropathological examination was undertaken in each case. A significant relationship between the presence and degree of vasospasm and ischemic brain damage was found. Furthermore, even though intracerebral hematoma probably increased the risk of infarction associated with vasospasm, hematoma per se did not increase the incidence of ischemic brain damage.

Symptomatic unruptured giant aneurysms: medical treatment

Medical hypotensive therapy, usually limited to cases with proved haemorrhage, has now been applied to three cases of giant or "very large" aneurysm which were symptomatic but unruptured. All three patients improved. With three cases, the only conclusion that is drawn at this time is that medical treatment may indeed offer something for even this category of aneurysm as well as for the much more common smaller aneurysms that have ruptured and whose excellent response to both early and long term medical hypotensive therapy has already been established.