Endovascular strategy or open repair for ruptured abdominal aortic aneurysm: one-year outcomes from the IMPROVE randomized trial

Abstract

Aims: To report the longer term outcomes following either a strategy of endovascular repair first or open repair of ruptured abdominal aortic aneurysm, which are necessary for both patient and clinical decision-making.

Methods and results: This pragmatic multicentre (29 UK and 1 Canada) trial randomized 613 patients with a clinical diagnosis of ruptured aneurysm; 316 to an endovascular first strategy (if aortic morphology is suitable, open repair if not) and 297 to open repair. The principal 1-year outcome was mortality; secondary outcomes were re-interventions, hospital discharge, health-related quality-of-life (QoL) (EQ-5D), costs, Quality-Adjusted-Life-Years (QALYs), and cost-effectiveness [incremental net benefit (INB)]. At 1 year, all-cause mortality was 41.1% for the endovascular strategy group and 45.1% for the open repair group, odds ratio 0.85 [95% confidence interval (CI) 0.62, 1.17], P = 0.325, with similar re-intervention rates in each group. The endovascular strategy group and open repair groups had average total hospital stays of 17 and 26 days, respectively, P < 0.001. Patients surviving rupture had higher average EQ-5D utility scores in the endovascular strategy vs. open repair groups, mean differences 0.087 (95% CI 0.017, 0.158), 0.068 (95% CI -0.004, 0.140) at 3 and 12 months, respectively. There were indications that QALYs were higher and costs lower for the endovascular first strategy, combining to give an INB of £3877 (95% CI £253, £7408) or €4356 (95% CI €284, €8323).

Conclusion: An endovascular first strategy for management of ruptured aneurysms does not offer a survival benefit over 1 year but offers patients faster discharge with better QoL and is cost-effective.

Clinical trial registration: ISRCTN 48334791.

Keywords: Aneurysm; Aorta; Cost-effectiveness; Rupture; Stent grafts; Surgery.

Figure 1

CONSORT diagram showing flow of patients through the trial. AAA, abdominal aortic aneurysm; rAAA, ruptured abdominal aortic aneurysm; 23% of ruptured abdominal aortic aneurysms were juxtarenal with an aortic neck length <10 mm, 75% infra-renal, and 2% aorto-iliac. ^aOne hundred and forty-nine endovascular aneurysm repair and 110 open repair (27 open repairs in patients suitable for endovascular aneurysm repair, breach of protocol mainly for operational reasons, e.g. endovascular suite in use or inadequately staffed), ^b210 open repairs and 33 endovascular aneurysm repairs in breach of protocol, mainly for avoidance of general anaesthesia. ⁺Follow-up pertains to endpoints other than mortality. ^{^}One patient mortality known to 30 days and one patient mortality known to 3 months. Case record form (CRF) captures re-interventions and re-admissions, and outpatient visits to the trial hospital.

Figure 2

(A) Kaplan-Meier estimates by randomized group, across all patients (log-rank test p = 0.325) and (B) 1-year mortality odds ratios for specified subgroups.

Figure 3

Time to first re-intervention for the 502 patients with repair of ruptured aneurysm started. Log-rank test P = 0.674.

Figure 4

Hospital discharge (A) Overall time to discharge from hospital and (B) time to discharge home from primary hospital.

Figure 5

Uncertainty in the mean cost (£GBP) and Quality-Adjusted-Life-Year differences and their joint distribution for endovascular strategy vs. open repair.