Ruptured Abdominal Aortic and Iliac Artery Aneurysms

Aneurysms of the abdominal aorta (AAA) or the iliac arteries (IAA) are potentially lethal conditions that can be treated with surgical interventions. The recent shift towards endovascular treatment has resulted in lower immediate mortality from elective AAA surgery. Because of the high mortality from ruptured AAA (RAAA), screening programmes have been established in some countries with promising results. The prevalence of AAA, however, has been on the decline, possibly undermining the benefit of screening. We aimed to investigate the population-based mortality from RAAA and the treatment results in Finland, as well as investigate how many of the ruptures could potentially have been prevented by a screening programme. We also aimed to determine the actual size of an AAA or IAA, specifically an internal iliac artery aneurysm (IIAA), when it ruptures. The study period ranged from 2000 up until 2014. Patient data was obtained from the registries of Helsinki and Tampere University Hospitals. The Care Register for Health Care of the Institute for Health and Welfare was used to obtain data regarding the AAA and RAAA treatment for the entire country. Cause-of-death data came from Statistics Finland. Data on ruptured IIAA was collected from 28 hospitals in seven countries. The annual RAAA incidence in Finland was 9.5 per 100 000 inhabitants in 2000-2004 and fell to 6.8 per 100 000 in 2010-2014. The results of surgery improved for both elective and emergency operations. Population-based mortality also decreased, although over half of the RAAA patients still died outside the hospital. The turn-down rate was low compared to many international studies. Screening men for AAA at 65 years of age could theoretically prevent a maximum of 79% of AAA ruptures in men – who constitute over 75% of all RAAA patients. The average AAA size at the time of rupture was 77 mm in men and 71 mm in women. The corresponding IIAA size was 68 mm, with no significant sex-related difference. Population-based mortality of RAAA is declining. Most AAA ruptures occur at well over the 55-mm operative threshold diameter and over the age of 65 years. However, especially among smoking men, rupture at a younger age is not uncommon. IIAA rupture at under 4 cm is rare, and surveillance until this diameter is likely to be safe in most cases. To further lower mortality from RAAA a screening programme would be necessary.