Published online before print July 17, 2003, doi: 10.1161/01.STR.0000085566.16190.ED
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(Stroke. 2003;34:1857.)
© 2003 American Heart Association, Inc.
Original Contributions |
Editorial Comment—Prehemorrhage Risk Factors for Fatal Intracranial Aneurysm Rupture
Division of Neurosurgery, Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
In another important contribution from the Department of Neurosurgery at the University of Helsinki, where careful records and follow-up on patients with diagnosed intracranial aneurysms have been maintained for decades, evidence is presented that preexisting hypertension is associated with a higher fatality rate when unruptured cerebral aneurysms rupture. When dealing with the issue of unruptured cerebral aneurysms in the clinic, risk factors that may predict a higher risk of future bleeding (death notwithstanding) are assessed, factors that might justify the risk involved in prophylactic aneurysm repair. Previous study of this same captive Finnish population1 and other reports have suggested that the risk of future hemorrhage increases with aneurysm size,2,3 the presence of a local mass effect and symptoms resulting from the aneurysm,3,4 previous bleeding from another intracranial aneurysm,2,3 an aneurysm location in the posterior circulation,2,3 a multilobulated5 or long6 aneurysm shape, female sex,3 younger age at diagnosis,7 a familial history of aneurysm rupture,8 cigarette smoking,9,10 and heavy alcohol use.11 Arterial hypertension is another but perhaps less powerful predictor of rupture, as the authors discuss in this report.
Still, even in the presence of several of the aforementioned risk factors, the annual risk of an unruptured saccular aneurysm rupturing on an annual basis might be only 1% to 3%,12 a reassuringly low figure especially for older patients. Balancing this low annual bleeding rate, and especially for younger patients who bear a far greater cumulative lifetime risk of rupture, is the very high mortality and morbidity attached to each and every aneurysm rupture, a figure probably greater than 50%.2,7 This Finnish series indicates that the presence of arterial hypertension might make this risk even higher. One hundred forty-two patients with 181 unruptured aneurysms were followed for as long as 2 decades, for a total of 2577 person-years. Thirty-four aneurysm ruptures occurred, one half of which were fatal. Multiple stepwise logistic regression analysis revealed that systolic blood pressure values at follow-up before aneurysm rupture was the only indisputably significant predictor of death among patients with aneurysm rupture.
Clearly, hypertension requires aggressive treatment in patients harboring unruptured intracranial aneurysms, and the presence of hypertension (especially in patients whose blood pressure is difficult to control) can be reasonably applied along with other considerations in formulating a recommendation for or against aneurysm repair.
As important as the information contained in this report is, it still constitutes only level III evidence (data from nonrandomized, concurrent cohort studies), making it difficult to draw up unequivocal treatment guidelines regarding the management of unruptured intracranial aneurysms. As Weir concluded in a recent and comprehensive review of the subject, many patients fall into "a gray zone in which both components of medicine—art and science—must be brought to bear."13
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- Ujiie H, Tamano Y, Sasaki K, et al. Is the aspect ratio a reliable index for predicting the rupture of a saccular aneurysm? Neurosurgery. 2001; 48: 495–503.[CrossRef][Medline] [Order article via Infotrieve]
- Juvela S, Porras M, Heiskanen O. Natural history of unruptured intracranial aneurysms: a long-term follow-up study. J Neurosurg. 1993; 79: 174–182.[Medline] [Order article via Infotrieve]
- Ronkainen A, Hernesniemi J, Puranen M, et al. Familial intracranial aneurysms. Lancet. 1997; 349: 380–384.[CrossRef][Medline] [Order article via Infotrieve]
- Weir BK, Kongable GL, Kassell NF, et al. Cigarette smoking as a cause of aneurysmal subarachnoid hemorrhage and risk for vasospasm: a report of the Cooperative Aneurysm Study. J Neurosurg. 1998; 89: 405–411.[Medline] [Order article via Infotrieve]
- Juvela S, Poussa K, Porras M. Factors affecting formation and growth or intracranial aneurysms: a long-term follow-up study. Stroke. 2001; 32: 485–491.
[Abstract/Free Full Text] - Longstreth WR Jr, Nelson LM, Koepsell TD, et al. Cigarette smoking, alcohol use, and subarachnoid hemorrhage. Stroke. 1992; 23: 1242–1249.
[Abstract/Free Full Text] - Bederson JB, Awad IA, Wiebers DO, et al. Recommendations for the management of patients with unruptured intracranial aneurysms: a statement for healthcare professionals from the Stroke Council of the American Heart Association. Stroke. 2000; 31: 2742–2750.
[Free Full Text] - Weir B. Unruptured intracranial aneurysms: a review. J Neurosurg. 2002; 96: 3–42.[Medline] [Order article via Infotrieve]
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