Provider volume and long-term outcome after elective abdominal aortic aneurysm repair

Abstract

Background: Robust risk-adjusted analyses have demonstrated that a reduction in perioperative mortality is associated with the repair of an abdominal aortic aneurysm (AAA) in centres with a high operative caseload (volume). However, the long-term impact of this volume-related effect on mortality remains unknown.

Methods: Demographic and clinical data were extracted from UK Hospital Episodes Statistics for patients undergoing elective repair of an infrarenal AAA from 1 April 2000 to 31 March 2005. The long-term mortality of this cohort was investigated through linkage to the UK Office for National Statistics (ONS) registry. Risk-adjusted survival was analysed using Cox proportional hazards modelling to identify the effect of hospital volume on long-term mortality.

Results: A total of 14 396 patients with mean age of 72 years, of whom 85.7 per cent were men, underwent elective repair of an infrarenal AAA in England. They were linked to follow-up using ONS data. Risk-adjusted analysis of all-cause mortality by Cox proportional hazards modelling demonstrated a significant effect of hospital volume across all quintiles up to 2 years (P = 0.013). Remodelling the data after excluding in-hospital mortality still demonstrated the significant effect of hospital volume on late outcome.

Conclusion: There is a long-term benefit to patients who undergo elective AAA repair in a high-volume hospital.