Rupture of Abdominal Aortic Aneurysms in Patients Under Screening Age and Elective Repair Threshold.

Objectives: The objective of this study was to identify the proportion of abdominal aortic aneurysm ruptures that occur before the screening age or threshold diameter for operative repair is reached.

Methods: The study was a retrospective analysis of RAAA patients including all RAAA patients admitted to Helsinki (HUH) and Tampere University Hospitals (TaUH) during 2002-2013. The data for age, gender, and comorbidities were collected from vascular registry and patient records. Computed tomography images taken at the time of admission were used for the measurement of maximum anteroposterior (AP) aneurysm diameter at the time of rupture. Age and diameter data were compared with risk factors.

Results: A total of 585 patients diagnosed with RAAA were admitted to the two hospitals during the 12 year period. The mean age at the time of rupture was 73.6 years (SD 9.5, range 42-96 years). 18.3% of patients were under 65: 21.4% of men and 3.0% of women. Men were on average 8 years younger than women. The odds ratio (OR) for rupture before 65 years of age for smokers was 2.1 compared with non-smokers, and 28.4% of smokers were under 65 at the time of rupture. Of all RAAA patients, 327 had a computed tomography scan confirming rupture. The mean AP diameter of the aneurysm was 75.6 mm (SD 15.8, range 32-155 mm). The mean size was significantly lower in women than in men (70.5 vs. 76.8, p = .005).

Conclusions: The data from this study show that a fifth of men would not make it to the screening age of 65 before AAA rupture, the proportion being even larger in active smokers. The data from this study also supports the previous finding that aneurysm size at the time of rupture is significantly smaller in women.