Role of ribonuclease 1 and ribonuclease inhibitor 1 in thoracoabdominal aortic surgery Study design of a pilot study

A feared complication in open and endovascular thoracoabdominal aortic surgery is the systemic inflammatory response and associated multiorgan failure. As no causal therapeutic agents for suppression of this postoperative complication could be established despite intensive research, the identification and evaluation of new therapeutic target structures are crucial for the patients. The significant tissue damage during open surgery and the post-implantation syndrome (PIS) after endovascular thoracoabdominal aortic aneurysm (TAAA) repair result in the release of endogenous damage-associated molecular patterns (DAMP), such as extracellular ribonucleic acid (RNA), which induce and maintain the systemic inflammatory response. Ribonucleases (RNases) belong to the group of endogenous antimicrobial peptides. As a component of the innate immune system, RNases modulate the immune response to foreign pathogens and endogenous DAMPs. Ribonuclease inhibitor 1 (RNH1) represents the antagonist of RNase 1; however, the role of RNase 1 and RNH1 as a new additive treatment approach in systemic inflammation-associated multiorgan failure after surgical TAAA repair is still unclear. Therefore, the aim of the proposed pilot study is to analyze the role of RNase 1 and RNH1 as a new potential treatment target structure and/or biomarker in open and endovascular thoracoabdominal aortic repair and the associated inflammatory response.