Ruptured AAA at 2am — endovascular-first strategy, the 8-year crossover and the female threshold gap

Examiner prompts and model answers

He is hypotensive with a known 7 cm AAA at 2am — what is your strategy, and what does IMPROVE say it buys? Run the endovascular-first strategy if anatomy suits and the service exists: IMPROVE randomised 613 suspected ruptures and tied at 30 days (35.4 versus 37.4%, OR 0.92) with more patients home directly (94 versus 77%).^[14] At 1 year still tied on death (41.1 versus 45.1%) but with 17-versus-26-day stays, better quality of life and cost-effectiveness; at 3 years the strategy pulls ahead (48 versus 56%, 42 versus 54% in repaired ruptures) with tied reinterventions, QALY gains and lower costs — converging again by 7 years.^[15][16] Open repair where EVAR is unsuitable — only 174 of 275 confirmed ruptures qualified — and consent for reintervention as the norm.^[14]

He survives EVAR for rupture — what does the 15-year elective crossover mean for his follow-up? That his danger is not over: beyond 8 years open repair beats EVAR on total and aneurysm-related death (HR 1.25 and 5.82), driven by secondary sac rupture (13 versus 2 deaths), so he enters lifelong surveillance with reintervention — and post-rupture reintervention runs hotter than elective, with 13% needing mid-term reintervention mostly for endoleak, mandating bespoke protocols.^[10][17]

His wife asks whether her 5.1 cm threshold is the same as his — what do you tell her? That her number has no trial behind it: the surveillance-versus-repair randomisation ran primarily in men, her disease grows faster, ruptures smaller and repairs worse — so she is individualised early with vascular surgery on anatomy and fitness, and if she ruptures, the endovascular strategy carries a possible female advantage (OR 0.44 versus 1.18, interaction P 0.02) that still needs confirmation.^[26][14]

Which guideline are you following tonight, and why does NICE disagree with ESVS? ESVS 2024 frames the night — 160 recommendations covering permissive hypotension, aortic balloon occlusion, compartment syndrome and colonic ischaemia through to graft infection and endoleak follow-up.^[22] The NICE-versus-ESVS split is methodological: NICE runs open-first for elective AAA on old RCTs plus UK modelling (and open repair for ruptured men under 71 the same way), while ESVS runs EVAR-first on modern observational evidence — know both, follow your service's pathway, and never present one as error.^[23]