Treatment of abdominal and thoracic aortic aneurysms :  Aspects on epidemiology and surgical outcome

Sammanfattning: Aortic Aneurysm (AA) is a life-threatening condition when ruptured (RAA), requiring immediate repair for survival. Since the 50´s, open repair, replacing the diseased vessel with a prosthetic (synthetic) graft, has been the gold standard. In the 90's, a new minimal invasive surgical technique, endovascular aneurysm repair (EVAR) was developed and has since become the dominant surgical method of choice in RAA treatment. The aim of this thesis is to assess trends in epidemiology, treatment and outcome of aortic aneurysms, with special focus on RAA.Paper I is a population-based registry study of all surgical procedures performed for ruptured abdominal aortic aneurysm (RAAA) in Sweden 2008-2012. In this time period, some centres adhered to a distinct EVAR first strategy for treatment of RAAA, whilst others primarily performed open repair for RAAA. The analysis demonstrated no difference in mortality comparing centres with EVAR or open repair as primary treatment strategy. Paper II is a nationwide population-based register study presenting the epidemiology of all RAAA in Sweden from 1994 to 2013. The study demonstrated a decreasing mortality in RAAA over time, due to the combination of a falling incidence, increasing hospital admissions and increasing proportion of patients undergoing surgical repair. The survival after surgical intervention improved over time, mainly due to the introduction of EVAR.Paper III is a nationwide population-based register study to investigate long-term survival after ruptured abdominal aortic aneurysms (RAAA) repair in Sweden during twenty-four years (1994-2017). The study found that the long-term survival has improved over time, mainly explained by improved perioperative survival, despite that the operated patients generally became older and more fragile.Paper IV is a nationwide population-based register study covering the time period 1997 to 2017, assessing the epidemiology of operated intact and ruptured descending thoracic aortic aneurysms (dTAA and RdTAA) in Sweden. This analysis shows increased incidence of intact dTAA repair due to broad introduction of thoracic EVAR (TEVAR). Early postoperative mortality decreased, despite an increasing proportion of those undergoing repair being ≥80 years and with more comorbidities. No changes on incidence or mortality was detected among RdTAA repairs.In conclusion, modern treatment of aortic disease with endovascular techniques has resulted in a significant change in practice for treatment of RAA, and dTAA. The above-mentioned nationwide population-based register studies indicate that EVAR/TEVAR have resulted in improved survival of patients suffering from RAAA and the results after dTAA repair have improved.