Vagn Eskesen

Clinical Features and Outcome in 48 Patients with Unruptured Intracranial Saccular Aneurysms: A prospective consecutive study

During a 5-year period (1978-1983) the clinical features and operative morbidity/mortality were registered prospectively for all patients in Denmark with an unruptured symptomatic (27 patients) or incidental (21 patients) intracranial saccular aneurysm. A follow-up examination was performed 2 years after diagnosis of the aneurysm. Thirty symptomatic aneurysms in 27 patients most frequently involved the visual pathways or ocular motility (66%). The median diagnostic delay for patients with impaired visual acuity was 7 months but only 14 days for patients with impaired ocular motility. The localisation of the 30 symptomatic and 23 incidental aneurysms were: internal carotid artery (73% approximately 35%), anterior communicating artery (3% approximately 26%) and middle cerebral artery (7% approximately 35%). The diameters of 73% of the symptomatic aneurysms were greater than 10 mm, while the diameter of 74% of the incidental aneurysms were below 10 mm. The total operative morbidity and mortality were 15% and 4%, respectively. The mortality rate in the follow-up period was 10-11% mainly due to fatal bleeding from unoccluded aneurysms. In 21 survivors, a normal mental status was found in 43% and mild dementia was found in another 43%. The impaired visual acuity was unchanged in 67% of patients, while the ocular motility had normalised in 75%. A normal daily functional capacity was enjoyed by 57% while 43% had a moderate reduction, mostly due to visual disturbances.

Unruptured Intracranial Aneurysms: An Assessment of the Annual Risk of Rupture Based on Epidemiological and Clinical Data

From autopsy and neuroradiological studies a maximum prevalence of unruptured intracranial aneurysms (UA) of 0.5% in the general population is revealed. Studies concerning the incidence of aneurysmal subarachnoid haemorrhage (SAH) revealed 10 cases per 100,000 inhabitants per year. From these epidemiological parameters a minimum annual risk of 2% of rupture of an UA is calculated. It is in accordance with clinical studies, which also demonstrated an annual risk of UA rupture of at least 2%. No critical size of the UA predisposing to rupture has been found. Operation on diagnosed UA is recommended because of the serious prognosis after aneurysmal SAH (morbidity 20%-25% and mortality 50%-60%) and because the morbidity (4%) and the mortality (0%) after operative treatment of UA are very low.

The prognostic significance of intracerebral haematoma as shown on CT scanning after aneurysmal subarachnoid haemorrhage

In a prospective study of 1076 consecutive patients with aneurysmal subarachnoid haemorrhage (SAH), CT was carried out in 815 patients. CT visible intracerebral haematoma (ICH) was found in 42.6% of the 815 patients. There were no differences in age, pre-existing hypertension or sex between patients with or without ICH. Patients with ICH were in poorer clinical condition on admission, and had a poorer mental outcome and a higher mortality at the 2-year follow-up examination compared with patients without ICH. Of the 491 operated patients, there were in every group according to the clinical condition on admission fewer patients with a normal mental outcome and more fatal cases if an ICH was present after aneurysm rupture. This indicates that the acute brain dysfunction from SAH complicated by ICH is more likely to be followed by permanent cerebral damage compared to the corresponding acute cerebral dysfunction from SAH without ICH.

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.

Seasonal variation of aneurysmal subarachnoid haemorrhage

SummaryIn a prospective consecutive series of 1,076 patients with aneurysmal subarachnoid haemorrhage (SAH) admitted to the 6 Danish neurosurgical departments in the 5-year period April 1, 1978 to March 31, 1983 a significantly higher seasonal incidence of SAH was seen during spring and autumn compared to summer and winter. No significant seasonal differences in monthly mortality or between females and males were registered. Contrary to several other studies concerning cerebral apoplexy excluding SAH no explanation to the seasonal variation was obtained from differences in weather conditions. A correlation between seasonal variation of aneurysm rupture and physical activity is possible.

Clinical features and outcome in females and males with ruptured intracranial saccular aneurysms

Of 1076 patients with aneurysmal subarachnoid haemorrhage 674 were females and 402 males. No significant differences between females and males were seen as regards age, clinical condition on admission, pre-existing arterial hypertension and number of rebleeds. Angiographically demonstrated vasospasm was seen with a significantly higher incidence in females (p < 0.05) which may possibly explain a significantly poorer outcome in females compared with males (p < 0.05), despite the much higher rate in females of internal carotid artery aneurysms which have a significantly better prognosis compared with aneurysms at other sites.

Patients with ruptured intracranial saccular aneurysms: Clinical features and outcome according to the size

In the prospective consecutive Danish Aneurysm Study 192 patients (19%) had a ruptured intracranial aneurysm (RA) with a maximum diameter < 5 mm (small). In 524 (51%) and 306 patients (30%) the size was 5-10 mm (medium) and 11-24 mm (large), respectively. More patients with large RA (35%) were unconscious more than 1 h after the bleeding and had more CT-visualized haematomas (49%) compared with the patients with small RA (28 and 34%) and medium RA (27 and 37%). After 2 years, more patients with small RA and medium RA had resumed their previous occupation (49 and 49%), regained a normal daily functional capacity (55%, 55%) and normal mental outcome (29 and 32%) compared with the patients with large RA (34, 44 and 23%). The mortality was 47, 39 and 51% for patients with small, medium and large RA, respectively. With also a very serious prognosis after rupture of aneurysms of 10 mm or less and even less than 5 mm we also recommend surgical treatment of unruptured aneurysms of these sizes.

The influence of unruptured intracranial aneurysms on life expectancy in relation to their size at the time of detection and to age.

A theoretical evaluation of the lifetime probabilities of different outcomes in patients with unruptured intracranial aneurysms (UA) has been made using a life table method. The calculations were performed for aneurysm presenting ages from 20 to 70 years of age for men and women assuming an annual risk of aneurysm rupture of 1%, 2% and 3% and a rate of mortality after rupture of 50%. At 10, 20, 30, 40, 50 and 60 years after the diagnosis of an UA the probability of survival without bleeding is reduced below the expected probability of survival according to the life tables by the following percentages (assuming an annual risk of bleeding of 2%): 19%, 34%, 46%, 56%, 64% and 72%, respectively. A survey of the lifetime probabilities of four different outcomes for patients with an UA indicates a substantial reduction in life expectancy after the diagnosis of an UA. In most ages the surgical risks are more than balanced by the risks associated with an untreated unruptured aneurysm.

Pre-existing Arterial Hypertension in Subarachnoid Haemorrhage: An Unfavourable Prognostic Factor

In the Danish Aneurysm Study 1,076 patients were admitted with an aneurysmal subarachnoid haemorrhage in the 5-year period 1978-83. Pre-existing arterial hypertension, defined by the necessity for antihypertensive treatment at the time of admission was identified in 155 patients (15%). Nine hundred and two (85%) were normotensive. Nineteen patients were excluded because of inadequate information. Comparisons between the hypertensive and normotensive groups of patients showed no significant differences in sex-distribution, onset and course of the initial insult, results of primary CT-scan, location, size and numbers of aneurysms, number of rebleedings, and also in neurological symptoms, mental status, accommodation and occupation at a 2-year follow-up examination. The hypertensive group differed significantly in the following variables from the normotensive group. The median age was 8 years older (55 and 47 years of age respectively); a fewer number of patients fell into Hunt grade I-II on admission (34% and 43% respectively); an increased frequency of extracranial (23% and 13% respectively) and intracranial (35% and 18%, respectively) atherosclerosis was seen on angiography; a fewer number of patients underwent operation (48% and 66%, respectively); and at the 2-year follow-up examination an increased rate of overall mortality was evident (59% and 42%, respectively). There was an increased rate of mortality in patients in Hunt grade I-II on admission (52% and 22%, respectively) and an increased rate of mortality in patients who rebled (100% and 75%, respectively). Pre-existing arterial hypertension is an unfavourable prognostic factor after an aneurysmal subarachnoid haemorrhage.

The impact of rebleeding on the life time probabilities of different outcomes in patients with ruptured intracranial aneurysms. A theoretical evaluation.

SummaryIn order to strengthen patient-information a theoretical evaluation of the impact of rebleeding on the life time probabilities of different outcomes in patients with an aneurysmal subarachnoid haemorrhage (SAH) has been made using a life table method. The calculations were performed for SAH-presenting ages from 20 to 70 years assuming a rate of rebleeding of 50% in the first 6 months after the initial bleeding with a mortality rate of 70%, and the following years an annual rate of rebleeding of 3%, and with a mortality rate of 60%. A survey of the life time probabilities of the 4 different outcomes after an aneurysmal SAH shows the great life time reducing effect of rebleedings in all SAH-presenting ages.