The International Cooperative Study on the Timing of Aneurysm Surgery. The North American experience

Stroke. 1992 Feb;23(2):205-14. doi: 10.1161/01.str.23.2.205.


Background and purpose: The timing of aneurysm surgery after subarachnoid hemorrhage is a major neurosurgical controversy addressed by the International Cooperative Study on the Timing of Aneurysm Surgery (1980-1983). The present report examines the results of this trial in the subgroup of patients admitted to North American centers.

Methods: The method of study was a large, multicenter, prospective, epidemiological survey. Neurosurgeons were required to indicate prospectively the interval to planned aneurysm surgery at the time of patient admission. Outcome at 6 months was determined by a blinded evaluator, and overall management results were analyzed by the planned surgical interval.

Results: Seven hundred seventy-two (21.9% of the total study population) patients admitted from days 0 to 3 after subarachnoid hemorrhage were accrued in North American centers. Overall outcome in patients planned for surgery in days 0-3 was equivalent in terms of mortality (after adjustment for prognostic variables) to patients planned for days 11-32, but the early patients had significantly improved rates of good recovery (70.9% versus 61.7%, p less than 0.01). Patients planned for surgery during the days 7-10 interval had nearly twice the mortality of patients in the other intervals.

Conclusions: In contrast to the results from the overall trial, which found no difference between early and delayed surgery, results were best in North American centers when surgery was planned between days 0 and 3 after subarachnoid hemorrhage. These findings argue strongly for early diagnosis and referral for surgical intervention of North American patients suspected of having a ruptured cerebral aneurysm.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Cerebral Angiography
  • Epidemiologic Methods
  • Female
  • Health Surveys
  • Humans
  • International Cooperation
  • Intracranial Aneurysm / diagnostic imaging
  • Intracranial Aneurysm / mortality
  • Intracranial Aneurysm / surgery*
  • Male
  • Middle Aged
  • North America
  • Postoperative Care
  • Postoperative Complications
  • Preoperative Care
  • Prospective Studies
  • Survival Analysis
  • Time Factors
  • Tomography, X-Ray Computed