The design of the Canadian UnRuptured Endovascular versus Surgery (CURES) trial.

BACKGROUND Once a decision has been made to treat an intact aneurysm, the best treatment remains uncertain. Both surgical and endovascular management strategies are commonly performed for these lesions. Surgical clipping, for years the standard treatment, is gradually becoming supplanted by endovascular treatment. However, there is no randomized data available to compare the results of surgery versus endovascular treatment of unruptured aneurysms (UIAs). METHODS We report the design of the Canadian UnRuptured Endovascular versus Surgery (CURES) trial to compare angiographic and clinical outcomes following treatment of UIAs. RESULTS The Canadian pilot phase will serve two purposes: i) to determine feasibility of the pivotal international study, and ii) to determine the incidence of treatment failure, a composite primary end-point comprising the occurrence of either: failure to accomplish aneurysm obliteration with the initial treatment modality, a major saccular aneurysm remnant or recurrence, or intracranial hemorrhage following treatment at one year. The pivotal international study will address which strategy leads to the best overall clinical outcomes in terms of mortality, morbidity, and clinical efficacy. CURES is designed to be a pragmatic management trial with loose inclusion criteria. The pilot study plans to enroll 260 patients, a size sufficient (at 80% power and 0.05 significance) to detect a decrease in the incidence of treatment failure from 13% to 4%. The formulation of specific hypotheses for the pivotal phase awaits the preliminary CURES morbidity and mortality results. CONCLUSIONS The CURES trial intends to test surgical versus endovascular management strategies for the treatment of unruptured intracranial aneurysms.