Intracranial aneurysm and carotid artery stenosis.
In this issue of the Southern Medical Journal, Navaneethan et al (1) present a timely discussion of a difficult and uncommon dilemma of concomitant atherosclerotic cervical carotid artery stenosis Carotid arterial stenosis is a narrowing of the lumen of the carotid artery, usually by atheroma (a fatty lump or plaque causingatherosclerosis). Atheroma's may cause transient ischemic attacks (TIAs) and cerebrovascular accidents (CVAs) as it obstructs the bloodstream to the brain. and a giant middle cerebral artery Noun 1. middle cerebral artery - one of two branches of the internal carotid artery; divides into three branches
arteria cerebri, cerebral artery - any of the arteries supplying blood to the cerebral cortex aneurysm aneurysm (ăn`yrĭzəm), localized dilatation of a blood vessel, particularly an artery, or the heart. . Over the past decade, treatment strategies for both of these conditions have evolved considerably and continue to change as technical advancements are made.
Medical management with antiplatelet therapy versus surgical management with carotid endarterectomy (CEA CEA carcinoembryonic antigen.
CEA (Carcinoembryonic antigen) ) has been studied extensively in randomized ran·dom·ize
tr.v. ran·dom·ized, ran·dom·iz·ing, ran·dom·iz·es
To make random in arrangement, especially in order to control the variables in an experiment. prospective trials of carotid artery stenosis. Symptomatic patients with high-grade carotid artery stenosis (70 to 99%) with recent hemispheric or retinal transient ischemic attacks or nondisabling strokes had significantly better outcomes after CEA than comparable patients treated medically. (2) More modest benefits from CEA compared with medical therapy have been shown in symptomatic patients with lesser degrees of stenosis (50 to 69%), and for asymptomatic patients with moderate to severe stenosis. (3-5)
More limited studies have been performed for assessment of the role of carotid artery stenting (CAS), (6) and suggest that the safety of CAS may be equivalent to CEA. A phase III Carotid Artery versus Endarterectomy Endarterectomy Definition
Endarterectomy is an operation to remove or bypass the fatty deposits, or blockage, in an artery narrowed by the buildup of fatty tissue (atherosclerosis). Stenting Trial (CREST) sponsored by the National Institute of Neurologic Disorders and Stroke (NINDS NINDS Neurology A multicenter, double blinded, randomized trial–National Institute of Neurological Disorders and Stroke which evaluated the effects of tPA therapy in Pts with stroke. See Thrombolytic therapy, tPA. ) is currently accruing patients to compare the efficacy of CEA versus CAS.
Treatment of cerebral aneurysms traditionally has been performed via craniotomy Craniotomy Definition
Surgical removal of part of the skull to expose the brain.
A craniotomy is the most commonly performed surgery for brain tumor removal. and microsurgical techniques. Over the past decade, endovascular techniques including coiling and stenting have been developed as alternative treatments for some aneurysms. The goals of aneurysm treatment include reducing risks of hemorrhage and minimizing neurologic morbidity and death. Cerebral aneurysms are typically classified by their maximal diameter as small (less than 1 cm), large (1 to 2.5 cm) or giant (greater than 2.5 cm). Prospective studies have suggested that larger aneurysms carry higher risk of subarachnoid hemorrhage, (7) and giant aneurysms such as the one presented in this issue of the Journal have a poor natural history and are technically challenging to treat.
Factors affecting whether to treat an aneurysm include anatomy, patient age, neurologic condition, medical comorbidities, and whether or not the aneurysm has ruptured. Determining which technique to use, microsurgery microsurgery
Surgical technique for operating on minute structures, with specialized, tiny precision instruments under observation through a microscope, sometimes equipped with cameras to show the operation on a monitor. or an endovascular approach, is best determined through interdisciplinary collaboration between neurosurgeons and interventional neuroradiologists with expertise in these techniques. The International Subarachnoid Aneurysm Trial The International Subarachnoid Aneurysm Trial is a large multicentre, prospective randomised clinical medical trial, comparing the safety and efficacy of endovascular coil treatment and surgical clipping for the treatment of ruptured brain aneurysms. (ISAT ISAT Illinois Standards Achievement Test
ISAT International Subarachnoid Aneurysm Trial
ISAT Information Science and Technology
ISAT Information and Advisory Service on Appropriate Technology
ISAT Illinois State Assessment Test ), (8) a randomized prospective trial of over 2000 European patients with ruptured aneurysms, suggested better neurologic outcomes for patients treated with endovascular coiling compared with microsurgical clipping, but other studies have demonstrated that the durability of endovascular treatment of cerebral aneurysms may be considerably worse than microsurgical treatment and that rates of incomplete aneurysm obliteration or recurrence may be as high as 40 to 50%. (9)
As one can see, there remains considerable controversy with regard to the ideal treatment strategies for both intracranial aneurysms and occlusive occlusive /oc·clu·sive/ (o-kloo´siv) pertaining to or causing occlusion.
1. Occluding or tending to occlude.
2. atherosclerotic cervical carotid carotid /ca·rot·id/ (kah-rot´id) pertaining to the carotid artery, the principal artery of the neck.
n. disease. When they are identified simultaneously in the same patient, optimal management for both of these conditions are even less clearly defined, but a few reports have addressed this issue specifically. (10, 11) These studies report identification of intracranial aneurysms in 1 to 3% of patients evaluated for cervical carotid artery atherosclerotic disease, and that the presence of one of these conditions, in general, should not alter the management of the other.
At our institution, I suspect that this patient may have been treated with a CEA first and at a later date, craniotomy for microsurgical clipping of the aneurysm. One cannot argue with the good outcome achieved with the techniques of carotid artery stenting and aneurysm stenting and coiling achieved by the authors. The long-term effectiveness and durability of the coiling and stenting are less established, and long-term follow up is advisable. Creative and thoughtful application of new techniques to complex conditions such as the patient described by the authors can yield excellent outcome for challenging situations.
1. Naveenthan SD, Kannan VS, Osowo A, et al. Concomitant intracranial aneurysm and carotid artery stenosis: a therapeutic dilemma. South Med J 2006;99:757-758.
2. North American Symptomatic Carotid Endarterectomy Trial (NASCET NASCET Cardiology A clinical trial–North American Symptomatic Carotid Endarterectomy Trial designed to compare the outcomes of surgery plus medical therapy with medical therapy alone in Pts at risk for TIAs and CVAs. See Stroke, Transient ischemic attack. ) Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-453.
3. Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis: North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med 1998;339:1415-1425.
4. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA JAMA
Journal of the American Medical Association 1995;273:1421-1428.
5. Hobson RW II, Weiss DG, Fields WS, et al. Efficacy of carotid endarterectomy for asymptomatic carotid stenosis: the Veterans Affairs Cooperative Study Group. N Engl J Med 1993;328:221-227.
6. Yadav JS, Wholey MH, Kuntz RE, et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004;351:1493-1501.
7. International Study of Unruptured Intracranial Aneurysms (ISUIA) Investigators. Unruptured intracranial aneurysms: risk of rupture and risks of surgical intervention. N Engl J Med 1998;339:1725-1733.
8. Molyneux A, Kerr R, Stratton I, et al, International Subarachnnoid Hemorrhage Aneurysm Trial (ISAT) Collaborative Group. International Subarachnnoid Hemorrhage Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with rupture intracranial aneurysms: a randomized trial. Lancet 2002;360:1267-1274.
9. Brilstra EH, Rinkel GJ, van der Graaf Y, et al. Treatment of intracranial aneurysms by embolization with coils: a systematic review. Stroke. 1999;30:470-476.
10. Kappelle LJ, Eliasziw M, Fox AJ, et al. Small, unruptured intracranial aneurysms and management of symptomatic carotid artery stenosis: North American Symptomatic Carotid Endarterectomy Trial Group. Neurology 2000;55:307-309.
11. Carvi Y, Nievas MN, Haas E, et al. Unruptured large intracranial aneurysms in patients with transient cerebral ischemic Ischemic
An inadequate supply of blood to a part of the body, caused by partial or total blockage of an artery.
Mentioned in: Antiangiogenic Therapy, Subarachnoid Hemorrhage, Ventricular Fibrillation
ischemic episodes. Neurosurg Rev 2003;26:215-220.
Another flaw in the human character is that everybody wants to build and nobody wants to do maintenance. --Kurt Vonnegut
Michael R. Chicoine, MD
From the Department of Neurosurgery, Washington University School of Medicine Washington University School of Medicine, located in St. Louis, Missouri, is one of the most competitive and highly regarded medical schools and biomedical research institutes in the United States. , St Louis, MO.
Reprint requests to Michael R. Chicoine, MD. Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8057, St Louis, MO 63110. Email: email@example.com
Accepted March 24, 2006.