RCTs in determining treatment indications for intracranial aneurysms: What can we learn from history?

Many important issues regarding the management of intracranial aneurysms remain controversial. We review the role played by randomized trials in the determination of the best management of intracranial aneurysms in the early era of surgical clipping.

Landmark trials and cooperative studies are analyzed and results summarized in a narrative review.

The most convincing evidence in favour of surgical management of ruptured intracranial aneurysms came from early randomized trials conducted from the 1950s to 1970s. Large historical observational studies, performed between the 1970s and 2000, aiming to guide clinical practice, provided only statistical associations mixed with confounding variables. After the early RCTs, the next important gain in reliable knowledge occurred with completion of the ISAT trial, more than 25 years later.

The pioneering neurosurgeons of early trials can provide the inspiration necessary to make real progress in understanding the best clinical management of intracranial aneurysms.