O-013 - ABDOMINAL AORTIC ANEURYSM TREATMENT IN THE NORDIC COUNTRIES: ANALYSIS OF NATIONAL REGISTER DATA FROM 1998 TO 2017

TOPIC:
Abdominal Aortic Aneurysms
AUTHORS:
Laine M. (Department of Vascular Surgery, University of Helsinki and Helsinki University Hospital ~ Helsinki ~ Finland) , Gunnarsson K. (Section of Vascular Surgery, Department of Surgical Sciences, Uppsala University ~ Uppsala ~ Sweden) , Altreuther M. (Department of Vascular Surgery, St. Olavs Hospital ~ Trondheim ~ Norway) , Budtz-Lilly J. (Division of Vascular Surgery, Aarhus University Hospital ~ Aarhus ~ Denmark) , Sund R. (Institute of Clinical Medicine, University of Eastern Finland ~ Kuopio ~ Finland) , Mani K. (Section of Vascular Surgery, Department of Surgical Sciences, Uppsala University ~ Uppsala ~ Sweden) , Wanhainen A. (Section of Vascular Surgery, Department of Surgical Sciences, Uppsala University ~ Uppsala ~ Sweden) , Venermo M. (Department of Vascular Surgery, University of Helsinki and Helsinki University Hospital ~ Helsinki ~ Finland)
Introduction:
Abdominal aortic aneurysm (AAA) carries a high mortality in case of rupture. Because unruptured aneurysms are predominantly asymptomatic screening programmes have been implemented in some countries. In the Nordic countries, consisting of Sweden, Denmark, Finland and Norway with a combined population of over 25 million, national screening programme for AAA is active only in Sweden, where it was introduced gradually from 2006 and reached national coverage in 2015. A significant fall in the incidence of ruptured AAA (RAAA) has coincided with the introduction of screening in Sweden, suggesting a causal relationship(1,2). However, there are indications that RAAA incidence is falling also in places without screening programmes (3,4,5). This may be due to fall in prevalence of AAA or increased detection of asymptomatic AAAs as incidental findings in imaging studies. This could lead to increase in elective AAA repair. If the prevalence itself is declining, so would presumably the total number of repairs. Our aim was to utilise the robust national registries in the Nordic counties to identify trends in AAA repair throughout the region as well as analyse treatment results.
Methods:
Data on all operations for AAA and RAAA from 1998 to 2017 were extracted from the relevant national health care registries of each country. Data from Denmark was unavailable at the time of writing and is not included in this analysis. Patients were identified based on ICD-10 codes I71.3 and I71.4 and coding for open and endovascular AAA repair procedures. Reoperations were excluded from the analysis. Data was compiled and analysed without identifiable patient-level data in compliance with General Data Protection Regulation of the European Union. Patients were grouped into three age-categories and the twenty-year period was divided into four five-year segments. Data on patient gender and type of operation was included. Long term survival was analysed using the life table method.
Results:
A total of 30422 intact AAA repairs and 10885 RAAA repairs were identified. Patient characteristics are shown in table 1. Women accounted for 16% of patients undergoing intact AAA repair and 17% of those undergoing RAAA repair. EVAR was performed in 42% of cases with intact AAA and 16% with RAAA. Repair rates for intact AAA in men increased slightly in all countries, although Sweden was the only country which showed increase in patients aged 65-80 years, in all countries there was a marked rise in repair rates for men over 80 years (Figure 1). Combined repair rates for AAA and RAAA remained stable in the entire population but showed a slight decrease in 65-80-year-olds and a clear increase in over 80-year-olds. Repair rates for women did not change significantly. Repair rates for RAAA fell in all countries, most prominently in Sweden (Figure 2). Thirty-day and 1-year mortality rates are presented in table 2. Median survival after intact AAA repair for men was 9.2 (95% CI 9.1-9.4) years and 8.8 (95% CI 8.4-9.1) years for women. After RAAA repair median survival was 3.6 (95% CI 3.3-3.8) years for men and 1.1 (95% CI 0.6-1.6) years for women. If, however, the patient survived the first 30 days, median survival was 5.9 (95% CI 5.5-6.4) years for women and 8.0 (95% CI 7.7-8.3) for men. Median survival was 4.1 (95% CI 3.7-4.5) years after RAAA repair with EVAR and 2.8 (95% CI 2.5-3.1) years with OAR. With intact repair the method showed a converse trend, median survival after EVAR was 7.7 (95% CI 7.7-7.9) years, whereas after OAR approximately 50% of patients were still alive at 10 years.
Conclusion:
A clear trend of declining number of RAAA repair for men was observed. This was most prominent in the Swedish population likely owing to the screening programme. Elective repair numbers increased slightly in Sweden among men eligible to screening. In Finland and Norway, an increase in in elective repair was seen only in patients over 80 years. EVAR showed a clear survival benefit after RAAA repair and an early benefit after intact repair but in the long term it was associated with poorer survival in elective cases. Patient selection may play a role in these results. Overall, repair rates in the Nordic countries have generally remained stable with operations shifting from emergency repair towards elective repair and elderly population.
References:
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