The ISAT trial (International Subarachnoid Aneurysm Trial) compared endovascular coiling versus surgical clipping for ruptured intracranial aneurysms. Which statement best reflects the key finding?

• A Surgical clipping showed superior long-term prevention of re-bleeding compared to coiling and better functional outcome at 1 year
• B Both techniques had identical outcomes for anterior communicating artery aneurysms but coiling was superior for posterior circulation aneurysms only
• C Coiling reduced immediate peri-procedural mortality but increased long-term re-rupture rates, negating overall survival benefit
• D Endovascular coiling significantly reduced death or dependence at 1 year (24% vs. 31%) compared to surgical clipping, establishing coiling as the preferred treatment for eligible aneurysms ✓

Explanation

The ISAT trial (2002, Lancet) was a pivotal RCT demonstrating that for ruptured intracranial aneurysms suitable for both treatments, endovascular coiling significantly reduced the primary outcome of death or dependence at 1 year (24% vs. 31%, absolute risk reduction 7%, p=0.001) compared to surgical clipping. Long-term follow-up confirmed sustained benefit in functional outcome. However, coiling carries higher risk of re-bleeding and incomplete occlusion, requiring long-term surveillance. Coiling is now the preferred approach for eligible aneurysms, with surgery reserved for specific anatomical situations or coiling failure.

Reference: Bailey & Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.