A meta-analysis and metaregression analysis of factors influencing mortality after endovascular repair of ruptured abdominal aortic aneurysms.

OBJECTIVE To determine factors that may influence the perioperative mortality after endovascular repair of ruptured abdominal aortic aneurysms (RAAAs) using metaregression analysis. METHODS A meta-analysis of all English-language literature with information on mortality rates after endovascular repair of RAAAs was conducted. A metaregression was subsequently performed to determine the impact on mortality of the following 8 factors: patient age; mid-time study point; anaesthesia; endograft configuration; haemodynamic instability; use of aortic balloon; conversion to open repair; and abdominal compartment syndrome. RESULTS The pooled perioperative mortality across the 46 studies (1397 patients) was 24.3% (95% CI: 20.7-28.3%). Of the 8 variables, only bifurcated approach was significantly associated with reduced mortality (p = 0.005). A moderate negative correlation was observed between bifurcated approach and haemodynamic instability (-0.35). There was still a strong association between bifurcated approach and mortality after simultaneously adjusting for haemodynamic instability, indicating that the latter was not a major factor in explaining the observed association. CONCLUSIONS Endovascular repair of RAAAs is associated with acceptable mortality rates. Patients having a bifurcated endograft were less likely to die. This may be due to some surgeons opting for a bifurcated approach in patients with better haemodynamic condition. Further studies will be needed to clarify this.