Project: Research project

Project Details


The prevention of hemorrhagic stroke in patients with unruptured
intracranial aneurysms (UIA) may be possible with a better understanding
of the natural history of these lesions. The current study forms part of
the International Study of Unruptured Intracranial Aneurysms (ISUIA). Its
primary objectives are: (1) to define a critical aneurysmal size above
which there is a significant risk of future rupture among patients without
a history of subarachnoid hemorrhage (SAH); (2) to compare the risk of
future rupture of UIA, disability, and death among patients with and
without a history of prior SAH from a different source and to determine
whether or not the risk of future rupture varies directly with aneurysmal
size among patients with a history of prior SAH; and. (3) to define the
surgical morbidity and mortality involved with repair of UIA across a
broad spectrum of populations and surgeons with special reference to the
size and location of the aneurysm, history of SAH from another source, and
other confounding variables such as age and associated medical conditions. The study will involve collecting and analyzing both retrospective and
prospective data. The retrospective portion includes identification of
1,500 patients with unoperated UIA by records review (from 1970 to 1989)
at participating centers. Approximately half of these patients will have
no history of SAH (Group I) and the other half will have a history of SAH
from a separate intracranial aneurysm that has been surgically repaired
(Group II). Hard copy cerebral arteriograms will be reviewed centrally
and patients will be followed by a standardized patient questionnaire with
a minimum follow-up of five years from angiographic diagnosis of UIA.
During the first three years of the study, 2,000 additional patients will
be identified prospectively, for a two to five year prospective follow-up.
Approximately 800 of these patients will be unoperated (Groups I and II)
and 1,200 others will be operated. Prospectively identified patients will
be followed at one month and annually until study termination. The primary analysis will examine neurologic outcome, specifically, fatal
and nonfatal intracranial hemorrhagic stroke secondary to aneurysmal
rupture. Secondary analyses of neurologic outcome will examine other
aneurysmal complications such as ischemic stroke and death from all
causes. The prognostic significance of several independent, variables
with respect to stroke due to aneurysmal rupture and mortality, will also
be analyzed using a Cox proportional hazards model.
Effective start/end date9/9/912/28/11


  • National Institutes of Health: $1,448,119.00


  • Medicine(all)
  • Neuroscience(all)

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