What’s the denominator? An 8-year audit of ruptured abdominal aortic aneurysm outcomes, including rates of conservative and palliative management

Background: A ruptured aortic aneurysm (rAAA) is a surgical emergency with rapid onset and poor survival. Expedited diagnosis and surgical repair are required to prevent exsanguination. Extensive literature compares outcomes of endovascular and open repair but there is little discussion of the denominator – the patients undergoing non-operative palliative management. Without this, all reported outcomes are confounded by case selection. We carried out this review to learn more about those operated on and to include the rate of palliation to learn more about overall outcomes. Methods: A retrospective note review of the electronic patient record identified all rAAAs treated at Addenbrooke’s hospital between January 2015 and November 2022. Demographics, treatment strategy, mortality, pre-operative imaging, transfusion requirement and inpatient stay were interrogated. Results: There were 209 rAAAs identified. Management was with open surgery (44%), endovascular surgery (36%) and palliation (20%). Open repair was associated with higher mortality, longer inpatient and ITU stay, and larger transfusion requirements than endovascular repair. Open repair was associated with a higher rate of return to theatre in the short term, while endovascular repair (EVAR) had a higher rate in the long term. 7% of palliative rAAAs remained alive at one year. Conclusions: An EVAR-first approach results in lower mortality rates and better short-term outcomes. Although interventional outcomes are widely reported, approximately 20% of the caseload is palliated. This denominator should be reported alongside conventional outcomes to address the bias of case selection and resource allocation and to provide a more comprehensive picture of overall outcomes.