A protocol-based treatment for ruptured abdominal aortic aneurysm contributed to improving aorta-related mortality: a retrospective cohort study

Background Recent guidelines state that improving the survival rate of patients with ruptured abdominal aortic aneurysm (rAAA) requires a protocol or algorithm for the emergency management of these patients. We aimed to investigate whether introducing a protocol treatment for rAAA improves clinical outcomes compared with the pre-protocol strategy. Methods At our institution, 92 patients treated for rAAA between June 2008 and August 2022 were retrospectively analyzed. In 2014, the protocol-based treatment was introduced comprising a transfer algorithm to shorten the time to proximal control, use of an endovascular occlusion balloon, strict indications for endovascular aortic aneurysm repair (EVAR) or open surgical repair, and perioperative care, including for abdominal compartment syndrome (ACS). Clinical outcomes were compared between the protocol and pre-protocol group, including operative status, all-cause mortality, and rAAA-related death at 30-day, in-hospital, and 1-year postoperative follow-ups. Results Overall, 52 and 40 patients received the protocol-based and pre-protocol treatments, respectively. EVAR was more frequently performed in the protocol group. The rate of achieving time to proximal control was significantly faster, and the transfusion volume was lower in the protocol group. ACS occurred more frequently in the protocol group with a higher EVAR. No difference was found in all-cause mortality between the two groups. The protocol group exhibited fewer rAAA-related deaths than the pre-protocol group during the following time points: 30 days (9.6% vs. 22.5%), during the hospital stay (11.5% vs. 30.0%), and 1 year (14.5% vs. 31.5%). Conclusions The protocol-based treatment improved the survival rate of patients with rAAA. Keywords: Ruptured abdominal aortic aneurysm, Open surgical repair, Endovascular aortic aneurysm repair, Endovascular occlusion balloon, Abdominal compartment syndrome