Re-Interventions after Repair of Ruptured Abdominal Aortic Aneurysm: Mid-Term Results of the Improve Trial

Abstract

Introduction - After elective abdominal aortic aneurysm (AAA) repair, re-interventions are more common after endovascular repair (EVAR) than open repair. There is some evidence that re-interventions also may be more common after successful repair of ruptured AAA. The aim of this study describe the severity of re-interventions, as perceived by both patients and clinicians, in the mid-term following ruptured AAA repair in patients randomised in the IMPROVE trial and to assess how whether these were associated with baseline aortic morphology. Methods - The IMPROVE trial randomised 613 patients to either an endovascular strategy (n=316) or open repair (n=297) at 30 hospitals, September 2009 to July 2013. Randomization in a 1:1 ratio, using variable block sizes, was computer generated by an independent contractor. 502 patients, had repair of ruptured AAA started and were followed up for 3 years for aneurysm-related re-interventions. The severity of re-interventions (arterial, laparotomy-related or other) was scored by trial investigators and separately by a patient focus group. The admission CT scans were measured in a core laboratory for maximum diameter, aneurysm neck and common iliac morphology. Results - There were 230 aneurysm-related re-interventions recorded within 3 years of randomisation; 121 and 109 in the endovascular strategy (n=259) and open repair (n=243) groups respectively, HR 1.02 [95%CI 0.79,1.32], p=0.88. Overall 28% of each group required at least one re-interventions, with about half of these being graded as severe by clinicians. The time to first severe re-intervention also was similar between the randomised groups. The time to the first arterial re-interventions was associated with increased common iliac artery diameter, the hazard ratio per 9mm increase in diameter was 1.48 (1.13,1.93), p=0.004, otherwise there were no significant associations with baseline morphology, including aortic diameter. The patient focus group had a different ranking of re-intervention severity from clinicians, rating amputation as the most severe re-intervention. But again, from the patient perspective the rates were similar after EVAR and open repair, but amputation (n=7) and unclosed stomas (n=5) were more common after open repair whereas secondary rupture (n=3) was more common after EVAR. Conclusion - The mid-term re-intervention rates and severity were similar in the endovascular strategy and open repair groups. Increasing baseline iliac diameter increased the rate of arterial re-interventions. Reporting metrics should change to accommodate patient ratings of re-interventions.