Trends in abdominal aortic aneurysm surgery in Scotland (1971-1984).

The trends in diagnosis, operative workload and mortality of patients with abdominal aortic aneurysm in Scottish hospitals between 1971 and 1984 were analysed using the Scottish Hospital In-patient Statistics. The frequency of diagnosis of aneurysm increased from 25.8 per 100,000 population aged over 55 in 1971 to 63.6 per 100,000 in 1984. The proportion of diagnosed aneurysms treated by operation rose from 24% in 1971 to 41% in 1984, resulting in a 4-fold increase in operative workload. Despite the rise in diagnosis of abdominal aortic aneurysm, the ratio of elective to emergency procedures has only improved slightly during the 14 years, the majority still being operated on as emergencies. The operative mortality following elective procedures fell from 10.5% in 1971 to 4.3% in 1984, while that for emergencies fell from 50% to 36%. The reasons for the increased surgical workload are multifactorial. It is not solely a consequence of an ageing population as the proportion of Scots aged over 55 years increased by only 4% during this period. The evidence from this study suggests that the rise in workload is secondary to an increase in the frequency of diagnosis of abdominal aortic aneurysm in all age groups and to the fact that a greater proportion of diagnosed cases are now offered surgery.