Published online before print December 2, 2002, doi: 10.1161/01.STR.0000037788.62597.70
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(Stroke. 2002;33:2734.)
© 2002 American Heart Association, Inc.
Letters to the Editor |
Worsening in Ischemic Stroke Patients: Supplementary Activation of Cerebral Hemodynamic With EC/IC Bypass
Department of Neurosurgery, University of Muenster (UKM), Muenster, Germany
To the Editor:
In a recently published editorial, Caplan propounded a question for new therapy strategy in ischemic stroke patients.1 He pointed out 3 main factors that are responsible for progression and worsening of neurological deficits in patients with noncardioembolic stroke. According to Steinke and Ley,2 one of these factors concerns reduced blood flow in the ischemic zone following occlusive disease of the supplying arteries. In respect of discussed facts, Caplan concluded that the only efficient therapy for worsening in stroke patients is an augmentation, ie, improvement in cerebral blood supply.
In addition to his proposal about either pharmacological or surgical management (eg, by established carotid endarterectomy),3,4 there is, in our opinion, a method of extracranial-intracranial bypass (EC/IC bypass), which should be considered in selected patients for improving circulation in the brain, if reopening of carotid obstructive lesion is impossible.
Caplan himself commented that there is a group of patients in whom the long-occluded vessels could not be reopened, by neither surgical methods nor thrombolysis.
We have experience with such patients, when progression of brain ischemia occurred despite established management procedures (such as sufficient anticoagulating therapy, among others) in conformity with the recommendations and guidelines of scientific societies, eg, the American Heart Association.5
Various studies have been published in the past 30 years—including the experiences of the senior authors (S.P., H.W.)—on microsurgical brain revascularization (eg, EC/IC bypass) of occlusive diseases,6–8 confirming regression of the clinical symptoms after this surgical procedure, even in noncardioembolic stroke patients with progression of deficit. Who among these patients with extracranial or intracranial artery occlusive disease are definitely proper candidates for such a revascularization is still not established. Unfortunately, since the 1985 publication of the data of the EC/IC Bypass Study Group,9 which did not consider a subgroup of patients with recurrent ischemic attacks based on occluded internal carotid artery and reduced cerebral vascular reserve, the research of surgical management of brain ischemia has not been generally of intensive interest. The problem of rational management, including neurosurgical procedures, for more benefit to the stroke patient should again be brought to the forefront, as Caplan suggested.
Still, there are not convincing data on whether ischemic brain attacks are of hemodynamic or thromboembolic origin. This matter should also be clarified in the future, using modern imaging techniques for more understanding and elucidation of cerebral hemodynamic pattern.10,11 In almost the same manner as other cerebrovascular diseases, an ischemic stroke presents a multidisciplinary therapeutic problem as well, which can only be solved by multidisciplinary cooperation, including neurosurgical revascularization procedures, if indicated.12
In conclusion, the surgical treatment with EC/IC bypass can be of benefit for prevention of stroke. Nevertheless, further studies must clarify this matter, as recommended by the Carotid Occlusion Surgery Study.13
References
1. Caplan LR. Worsening in ischemic stroke patients: is it time for a new strategy? Stroke. 2002; 33: 1443–1445. Editorial.
2. Steinke W, Ley SC. Lacunar stroke is the major cause for progressive motor deficits. Stroke. 2002; 33: 1510–1516.
3. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N England J Med. 1991; 325: 445–453.[Abstract]
4. European Carotid Surgery Trialists’ Collaborative Group. MRC European Carotid Surgery Trial: interim results for symptomatic patients with severe (70–99%) or with mild (0–29%) carotid stenosis. Lancet. 1991; 337: 1235–1243.[CrossRef][Medline] [Order article via Infotrieve]
5. Wolf PA, Clagett P, Easton JD, Goldstein LB, Gorelick PB, Kelly-Hayes M, Sacco RL, Whisnant JP. Preventing ischemic stroke in patients with prior stroke and transient ischemic attack: a statement for healthcare professionals from the Stroke Council of the American Heart Association. Stroke. 1999; 30: 1991–1994.
6. Schmiedek P, Piepgras A, Leinsinger G, Kirsch CM, Einhupl K. Improvement of cerebrovascular reserve capacity by EC-IC arterial bypass surgery in patients with ICA occlusion and hemodynamic cerebral ischemia. J Neurosurg. 1994; 81: 236–244.[Medline] [Order article via Infotrieve]
7. Palkovic S, Nadvornik P. Microanastomosis indication. J Neurosurg Sci. 1977; 21: 199–201.
8. Holbach KH, Wassmann H, Hohelüchter KL, Jain KK. Differentiation between reversible and irreversible post-stroke changes in brain tissue: its relevance for cerebrovascular surgery. Surg Neurol. 1977; 7: 325–331.[Medline] [Order article via Infotrieve]
9. The EC/IC Bypass Study Group. Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke. N Engl J Med. 1985; 313: 1191–1200.[Abstract]
10. Kim JH, Lee SJ, Shin T, Kang, KH, Choi PY, Kim JH, Gong JC, Choi N-C, Lim BH. Correlative assessment of hemodynamic parameters obtained with T2-weighted perfusion MR imaging and SPECT in symptomatic carotid artery occlusion. AJNR Am J Neuroradiol. 2000; 21: 1450–1456.
11. Derdeyn CP, Videen TO, Yundt KD, Fritsch SM, Carpenter DA, Grubb LL, Powers WJ. Variability of cerebral blood volume and oxygen extraction: stages of cerebral hemodynamic impairment revisited. Brain. 2002; 125: 595–607.
12. Fischer B, Palkovic S. Neonatal vein of Galen malformation. N Engl J Med. 2002; 346: 1553.
13. Adams HP, Powers WJ, Grubb RL, Clarke WR, Woolson RF, for the Carotid Occlusion Surgery Study. Preview of a new trial of extracranial-to-intracranial arterial anastomosis. Neurosurg Clin North Am. 2000; 36: 613–624.
Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
Response
Anecdotal reports before the EC/IC Bypass Study attested to the utility of bypass procedures, but the trial showed that the procedure as then performed was not effective. I agree with Fischer et al that there are some circumstances when bypass might be useful. A discussion at a Princeton conference focused on the issue of conducting a trial that studied the utility of bypass in patients with chronic hypoperfusion distal to a large-artery occlusion documented by modern neuroimaging techniques. Most attendees thought that the project was worthwhile. I do think that such a trial is now feasible.
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