A 45-year-old woman presents with sudden severe headache 'thunderclap', photophobia, and neck stiffness. Non-contrast CT head shows subarachnoid blood in the basal cisterns. DSA (digital subtraction angiography) identifies a 9 mm right posterior communicating artery aneurysm with a daughter sac (indicating instability). She is WFNS grade II. Which management is first-line according to current guidelines (ISAT trial data)?

• A Conservative management with nimodipine and delayed CT angiography
• B Surgical clipping as aneurysms with daughter sacs require mechanical clipping for definitive obliteration
• C Endovascular coiling (ISAT trial: coiling superior to clipping for accessible aneurysms in most patients) ✓
• D Flow diversion device (pipeline embolisation device) as preferred for PComA aneurysms

Explanation

The International Subarachnoid Aneurysm Trial (ISAT, Lancet 2002) was a landmark RCT showing that for ruptured intracranial aneurysms amenable to both coiling and clipping, endovascular coiling resulted in significantly better outcomes at 1 year (relative risk reduction in dependency/death 22.6%). Coiling is now the preferred first-line treatment for most aneurysms unless specific factors favour clipping (e.g., broad neck, complex morphology, MCA bifurcation). The daughter sac indicates instability, supporting urgent intervention (within 24-48 hours to prevent rebleeding) but does not exclusively mandate surgery. Flow diversion is not appropriate for acutely ruptured aneurysms.

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.