Combined intraarterial/intravenous thrombolysis for acute ischemic stroke.

BACKGROUND AND PURPOSE: The intravenous use of recombinant tissue-type plasminogen activator (rTPA) in acute ischemic stroke has been investigated in three large trials. Limited series have reflected outcome after local intraarterial thrombolysis (LIT) in the cerebral territory. The purpose of this study was to evaluate the safety and efficacy of combined intraarterial/intravenous thrombolysis using rTPA (actilyse) for acute ischemic stroke. METHODS: Forty-five patients with acute onset of severe hemispheric stroke and without signs of major cerebral infarction on early CT scans were randomized by order of admission. Twelve patients were treated with 50 mg actilyse (maximal dose, 0.7 mg/kg); three had occlusion of the internal carotid artery and nine had occlusion of the middle cerebral artery. Thrombolysis was started by LIT and continued intravenously within 6 hours of stroke onset. Outcome, assessed after 1 and 12 months according to the modified Rankin scale (MRS), was considered good (MRS score, 0-3) for patients who were functionally independent and poor (MRS score, 4-5) for those who were dependent or had died. RESULTS: In the thrombolysis group, outcome was good in eight patients at 1 month and in 10 patients at 12 months; in the control group, outcome was good in seven (21%) and 11 (33%) patients, respectively. Of the eight patients with a good outcome after thrombolysis, four had complete and one had partial recanalization. In the control group, the rate of intracerebral hemorrhage was 6%. Mortality at 1 month in the thrombolysis and control groups was 17% and 48%, respectively. CONCLUSIONS: Combined intraarterial/intravenous thrombolysis with low-dose rTPA may be a safe and effective treatment for acute ischemic stroke within 6 hours in carefully selected patients.

Biomechanical and structural assessment of transluminal angioplasty.

The increasing incidence of stroke is frequently maintained by the processes narrowing precerebral and cerebral arteries. That is why the surgical treatment of cerebrovascular disorders has increasingly included percutaneous transluminal angioplasty. However, the influence of transluminal angioplasty on the biomechanical properties of arterial wall have not been assessed so far. The cylindrical segments of left and right internal carotid artery, middle cerebral artery, anterior cerebral artery, vertebral artery, basilar artery and posterior cerebral artery were taken from 40 autopsy subjects aged from 20 to 75 who had no systemic lesions with the exception of atherosclerosis. The biomechanical examination and experimental transluminal angioplasty of the segments were carried out with special equipment developed for this purpose. The data were obtained using a TV camera assisted measurement and morphometric and histological methods. The examination of the biomechanical properties repeated after the experimental transluminal angioplasty shows the additional relative strain of the external diameter of vessel and the decrease of the arterial wall tangential elastic modulus in the circumferential direction. This suggests that if transluminal angioplasty results in sufficient structural damage of the arterial wall than there will be an improvement in the ability of the vessel diameter to increase under normal blood pressure conditions.

Biomechanical effects of experimental transluminal angioplasty.

Surgical treatment of vertebrobasilar circulation disorders includes percutaneous transluminal angioplasty more often recently. However, the biomechanical aspects of transluminal angioplasty have not been studied sufficiently so far. 148 left and right vertebral artery segments were taken from 24 autopsy subjects (14 male and 10 female) aged from 20 to 75, who had neither systemic nor cerebrovascular lesions. Biomechanical examination and experimental transluminal angioplasty (ETA) of the tubular segments of vertebral artery (VA) were carried out by the special equipment developed for this purpose. The data were obtained using telemetrical, morphometrical and hystological methods. The biomechanical properties taken in the conditioned physiological rate are different for each segment of the VA. The stiffness of VA wall increases with age (mainly after 40 years), particularly in segments V1 and V3. Nevertheless, after high intravascular pressure application the diameter response of VA to intravascular fluid pressure increases if sufficient structural damage of the arterial wall was made.