Re-interventions after repair of ruptured abdominal aortic aneurysm: a report from the IMPROVE randomised trial

Objectives: To describe the re-interventions after endovascular and open repair of rupture and investigate whether these were associated with aortic morphology. Methods: 502 patients from the IMPROVE randomised trial (ISRCTN48334791) with repair of rupture started were followed up for re-interventions for at least 3 years. Pre-operative aortic morphology was assessed in a core laboratory. Re-interventions were described by time (0-90 days, 3 months to 3 years as arterial or laparotomy-related, for a life-threatening condition or most feared by patients. Amputations were summarised across three ruptured AAA trials (IMPROVE, AJAX and ECAR) and odds ratios describing differences by randomised group were pooled via meta-analysis. Results: Re-interventions were most common in the first 90 days. Between 3 months and 3 years, 42 patients (13%) required at least one re-intervention, most commonly for endoleak or other endograft complication after EVAR (21/125, 17%) but overall rates were now slower at 9.5 and 6.0 re-interventions per 100 person-years for the endovascular strategy and open repair groups, p=0.090, with one third of the rates being for life-threatening conditions. Distal aneurysms were the commonest reason for re-intervention after open repair. Re-interventions for life-threatening conditions continued in both groups after 3 years. Arterial re-interventions within 3 years were associated with increasing common iliac artery diameter, odds ratio 1.48 [95%CI 0.13,0.93], p=0.004. Amputation, an uncommon re-intervention but that most feared by patients, occurred in 12 patients after open repair and 1 patient after EVAR within 1 year after rupture across 3 trials, with metayielding an odds ratio 0.2 [95%CI 0.05,0.88]. Conclusions: The rate of midterm re-interventions after rupture is more than double that after elective repair for both EVAR and open repair, suggesting the need for bespoke surveillance protocols. Amputations are much less common after EVAR than open repair.