Abdominal Aortic Aneurysm Repair: Factors influencing early and late mortality

Abstract

English summary Abdominal aortic aneurysm (AAA) is a common disease that particularly affects elderly individuals (> 60 years). Open surgical repair has for several decades been regarded as the standard treatment modality of AAA, while minimally invasive repair (EVAR) was introduced in the 1990s. Ruptured abdominal aortic aneurysm (rAAA) is a devastating event which will cause death if not treated within a short time. Repair of rAAA is reported to have a higher mortality in women than in men. Women also have a higher risk of rupture than men. In addition, AAA in women ruptures at a smaller size than AAA in men. The aims of this thesis were to investigate factors influencing early and late mortality following AAA repair during a 20-year period, with special emphasis on open surgery carried out consecutively at St. Olavs Hospital, Trondheim. In addition, we wanted to study the higher mortality among women following repair of rAAA and to investigate whether there were differences in preoperative risk factors or postoperative complications, which could explain this. Furthermore, we wanted to investigate whether preoperative white blood cell (WBC) count had any influence on early and long-term survival following surgery for AAA. In addition, we wanted to assess potential sex differences in preoperative WBC. During a 20- year period we observed an improvement in long-term survival in patients operated on for AAA. Comorbidities like cerebrovascular disease, diabetes, COPD and renal failure influenced long-term survival negatively. The over-all 5-year crude survival was 66 % in patients with non-ruptured aneurysms, and 37 % in patients with ruptured aneurysms. However, when excluding the 30-day mortality, the difference in long-term survival almost disappeared, including patients treated with EVAR In our cohort of rAAA, women had a significantly higher 30-day mortality after surgery than men. We observed significantly more autoimmune diseases among women during the last part of the study period. For other co-morbidities there were no differences between men and women. We could not identify any difference in preoperative risk factors or postoperative complications that could explain the higher mortality in women. Patients with WBC count above normal values >11 x10 9/L) prior to surgery for intact AAA had significantly higher 30-day mortality compared to patients with normal WBC count. Long-term survival was not statistically different in the two groups. We failed to identify any association between WBC count and 30-day mortality or long-term survival in patients undergoing surgery for rAAA. No sex differences in preoperative WBC count in patients undergoing surgery for intact AAA or rAAA were observed.