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Surgery of Unruptured, Asymptomatic Aneurysms: a Decision Analysis

Published online by Cambridge University Press:  18 September 2015

Richard Leblanc  and
Keith J. Worsley
Richard Leblanc*
Affiliation:
Department of Neurology & Neurosurgery, and Department of Mathematics and Statistics, McGill University, Montreal
Keith J. Worsley
Affiliation:
Department of Neurology & Neurosurgery, and Department of Mathematics and Statistics, McGill University, Montreal
*
3801 University Street, Montreal, Quebec, Canada H3A 2B4
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Abstract:

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Background: Asymptomatic cerebral aneurysms are diagnosed more frequently since the advent of computed tomography and magnetic resonance imaging. Their management is currently empirical. We have used decision analysis to place it on a more analytical basis. Methods: Decision analysis was used to determine the benefit in years of survival free of sequelae resulting from elective surgery of unruptured aneurysms over natural history. We took 2% as the annual rate of rupture (r), 73% as the risk of death or disability with rupture (M), and 6.5% for the average risk of elective surgery (S). Benefit was calculated from the equation L{[1-(1-r)L]M/2-S} [1] for life expectancy (L) corresponding to each quinquennial age group from age 15 to 100 years. Sensitivity analysis was performed to take into account increasing risk of elective surgery based on the size, and accessibility of the aneurysm, and variable risks of rupture and outcome. Results: A gain of at least one year of survival free of neurological sequelae is achieved by surgery compared to natural history for patients whose life expectancy is 19.5 years, corresponding to age 63.5 years for males and 68 years for females. The life expectancy at which a benefit accrues is longer (the patient is younger) for larger, less accessible aneurysms, for lower rates of rupture, and for lesser risks of death or disability from rupture. Conclusions: Elective surgery of unruptured asymptomatic aneurysms achieves an increased survival over the natural history of at least one year free of neurological sequelae in patients whose life expectancy is 19.5 years or more, using our baseline assumptions. Using equation [1], the corresponding life expectancy producing this benefit can be calculated to account for the increased surgical risk of large, poorly accessible aneurysms and for factors affecting natural history.

Type
Original Articles
Information
Canadian Journal of Neurological Sciences , Volume 22 , Issue 1 , February 1995 , pp. 30 - 35
Copyright
Copyright © Canadian Neurological Sciences Federation 1995

References

1. McCormick, WF, Acosta-Rua, GJ.The size of intracranial saccular aneurysms: an autopsy study. J Neurosurg 1970; 33: 422–427.CrossRefGoogle ScholarPubMed
2. Drake, CG.Management of cerebral aneurysms. Stroke 1981; 12: 273–283.CrossRefGoogle Scholar
3. Kassell, NF, Drake, CG.Timing of aneurysm surgery. Neurosurgery 1982; 10:514–519.CrossRefGoogle ScholarPubMed
4. Barnett, HJM.Some clinical features of intracranial aneurysms. Clin Neurosurg 1968; 16: 43–72.CrossRefGoogle Scholar
5. Locksley, HB.Natural history of subarachnoid hemorrhage, intracranial aneurysms and arteriovenous malformations. In: Sahs, AL, Perret, GE, Locksley, HB, et al., eds. Intracranial Aneurysms and Subarachnoid Hemorrhage: a Cooperative Study. Philadelphia: JB Lippincott, 1969; 37–108.Google Scholar
6. Levey, AS, Pauker, SG, Kassirer, JP.Occult intracranial aneurysms in polycystic kidney disease. N Engl J Med 1983; 308: 986–994.CrossRefGoogle ScholarPubMed
7. Life Insurance Fact Book, The American Council of Life Insurance, Washington District of Columbia 1990: 122–123.Google Scholar
8. Pakarinen, S.Incidence, aetiology, and prognosis of primary subarachnoid haemorrhage. Acta Neurol Scand 1967 (Suppl 19): 43.Google ScholarPubMed
9. Phillips II, LH, Whisnant, JP, O’Fallon, WM, Sundt, TM Jr. The unchanging pattern of subarachnoid hemorrhage in a community. Neurology 1980; 30: 1024–1040.CrossRefGoogle Scholar
10. Wirth, FP, Laws, ER Jr, Piepgras, D, Scott, RM.Surgical treatment of incidental intracranial aneurysms. Neurosurgery 1983; 12: 507–511.CrossRefGoogle ScholarPubMed
11. Leblanc, R, Worsley, K, Melancon, D, Tampieri, D.Angiographic screening and elective surgery of familial cerebral aneurysms. Neurosurgery 1994; 35:9–19.CrossRefGoogle ScholarPubMed
12. Auger, RG, Weibers, D.O.Management of unruptured intracranial aneurysms: a decision analysis. J Stroke Cerebrovas Dis 1991; 1: 174–181.CrossRefGoogle ScholarPubMed
13. Fleming, C, Wong, JB, Moskowitz, AJ, Pauker, SG.A peri-partum neurologic event: shooting from the hip. Med Decis Making 1988; 8:55–71.CrossRefGoogle Scholar
14. McNutt, RA, Pauker, SG.Competing rates of risk in a patient with subarachnoid hemorrhage and myocardial infarction: it’s now or never. Med Decis Making 1987; 7: 250–259.CrossRefGoogle ScholarPubMed
15. ter Berg, HW, Dippel, DW, Habbema, JDet al. Treatment of intact familial intracranial aneurysms: a decision-analytical approach. Neurosurgery 1988; 23: 329–234.CrossRefGoogle ScholarPubMed
16. van Crevel, H, Habbema, JDF, Braakman, R.Decision analysis of the management of incidental intracranial saccular aneurysms. Neurology 1986; 36: 1335–1339.CrossRefGoogle ScholarPubMed
17. King, JT, Berlin, JA, Flann, ES.Morbidity and mortality rates from elective surgery for asymptomatic unruptured intracranial aneurysms. A literature review and Meta-analysis. Presented at the 60,h Annual Meeting of the American Association of Neurological Surgeons, San Diego, California, April, 1994 (Poster 1093).Google Scholar
18. Drake, CG, Girvin, JP.The surgical treatment of subarachnoid hemorrhage with multiple aneurysms. In: Morley, TP., ed. Current Controversies in Neurosurgery. Toronto: W.B. Saunders; 1976: 274–278.Google Scholar
19. Jain, KK.Surgery of intact intracranial aneurysms. J. Neurosurg 1974; 40:495–498.CrossRefGoogle ScholarPubMed
20. Mount, LA, Brisman, R.Treatment of multiple aneurysms – symptomatic and asymptomatic. Clin Neurosurg 1974; 21: 166–170.CrossRefGoogle ScholarPubMed
21. Moyes, PD.Surgical treatment of multiple aneurysms and of incidentally-discovered unruptured aneurysms. J Neurosurg 1971; 35:291–295.CrossRefGoogle ScholarPubMed
22. Paterson, A, Bond, MR.Treatment of multiple intracranial arterial aneurysms. Lancet I: 1973; 1302–1304.CrossRefGoogle ScholarPubMed
23. Salazar, JL.Surgical treatment of asymptomatic and incidental intracranial aneurysms. J Neurosurg 1980; 53: 20–21.CrossRefGoogle ScholarPubMed
24. Samson, DS, Hodosh, RM, Clark, WJ.Surgical management of unruptured asymptomatic aneurysms. J Neurosurg 1977; 46: 731–734.CrossRefGoogle Scholar
25. Lozano, AM, Leblanc, R.Familial intracranial aneurysms. J Neurosurg 1987; 66:522–528.CrossRefGoogle ScholarPubMed
26. Winn, HR, Almaani, WS, Berga, SL, et al. The long-term outcome in patients with multiple aneurysms. J Neurosurg 1983; 59: 642–651.CrossRefGoogle ScholarPubMed
27. Heiskanen, O, Marttila, I.Risk of rupture of a second aneurysm in patients with multiple aneurysms. J Neurosurg 1970; 32: 295–299.CrossRefGoogle ScholarPubMed
28. Heiskanen, O.Risk of bleeding from unruptured aneurysms in cases with multiple intracranial aneurysms. J Neurosurg 1981; 55: 524–526.CrossRefGoogle ScholarPubMed
29. Weibers, DO, Whisnant, JP, Sundt, TM Jr., O’Fallon, M.The significance of unruptured intracranial saccular aneurysms. J Neurosurg 1987; 66:23–29.CrossRefGoogle Scholar
30. Kassell, NF, Tomer, JC.Size of intracranial aneurysms. Neurosurgery 1983; 12: 291–297.CrossRefGoogle ScholarPubMed
31. Weibers, DO, Whisnant, JP.Response. N Engl J Med 1981; 305–399.Google Scholar
32. Schievink, WI, Piepgras, DG, Wirth, FP.Rupture of previously documented small asymptomatic saccular intracranial aneurysms. J Neurosurg 1992; 76: 1019–1024.CrossRefGoogle ScholarPubMed
33. Sacco, RL, Wolf, PA, Bharucka, NEet al. Subarachnoid hemorrhage and intracranial hemorrhage natural history, prognosis, and procursive factors in the Framingham study. Neurology 1984; 34: 847–854.CrossRefGoogle Scholar
34. Longstreet, WT, Koepsell, TD, Yerby, MS, Van Belle, G.Risk factors for subarachnoid hemorrhage. Progress review. Stroke 1985; 16: 377–385.CrossRefGoogle Scholar
35. Edner, G, Kãgstrõm E, Wallstedt, L.Total overall management and surgical outcome after aneurysmal subarachnoid hemorrhage in a defined population. Br J Neurosurg 1992; 6: 409–420.CrossRefGoogle Scholar
36. Nakagawa, T, Hashi, K.The incidence and treatment of asymptomatic, unruptured cerebral aneurysms. J Neurosurg 1994; 80: 217–223.CrossRefGoogle ScholarPubMed
37. Solomon, RA, Fink, ME, Pile-Spellman, J.Surgical management of unruptured intracranial aneurysms. J Neurosurg 1994; 80: 440–446.CrossRefGoogle ScholarPubMed
38. Dix, GA, Gordon, W, Sutherland, IS, Sutherland, GR.A comparative study of the surgical management between ruptured and unruptured intracranial aneurysms. Can J Neurol Sci 1994; 21: S-22 (Abstract).Google Scholar
39. Fisher, M, Davidson, RI, Marcus, EM.Transient focal cerebral ischemia as a presenting manifestation of unruptured cerebral aneurysms. Ann Neurol 1980; 8: 367–372.CrossRefGoogle ScholarPubMed