Postoperative bioactive adrenomedullin is associated with the onset of ARDS and adverse outcomes in patients undergoing open thoracoabdominal aortic surgery.

Cytokine-mediated systemic inflammation after open thoracoabdominal aortic aneurysm (TAAA) repairs plays a pivotal role in disrupting circulatory homeostasis, potentially leading to organ dysfunction. The bioactive form of adrenomedullin (bio-ADM) is a peptide hormone with immunomodulatory and vasomotor effects, making it a potential diagnostic agent in these cases. This retrospective, bicentric study, conducted between January 2019 and December 2022, recruited 36 elective open TAAA repair patients in two German centres. Serum and plasma samples were collected at multiple time points to measure bio-ADM levels. The primary objective was to evaluate the association of bio-ADM levels with the onset of acute respiratory distress syndrome (ARDS), with secondary endpoints focusing on mortality and SIRS-related morbidity. Results showed a significant association between postoperative bio-ADM levels (12-48 h after surgery) and the onset of ARDS (p < .001), prolonged ventilation (p = .015 at 12h after surgery), atrial fibrillation (p < .001), and mortality (p = .05 at 24h). The biomarker was also strongly associated with sepsis (p = .01 at 12 h) and multi-organ dysfunction syndrome (MODS) (p = .02 at 24 h after surgery). The study underscores the potential utility of bio-ADM as a diagnostic tool for identifying patients at risk of postoperative complications following open TAAA repairs.

The role of Proenkephalin A 119-159 in the detection of acute kidney injury after open thoracoabdominal aortic repair.

Background: Acute kidney injury (AKI) after open thoracoabdominal aortic aneurysm repairs (TAAA) is a common postoperative complication, associated with increased mortality and morbidity. Early detection and management of the kidney tissue damage remains of paramount importance. The aim of this prospectively conducted, observational trial was to evaluate the clinical applicability of Proenkephalin A 119-159 (penKid) for the detection of postoperative AKI. Patients and methods: Thirty-six patients, planned for elective open TAAA repairs from January 2019 to December 2022, were recruited in two German centres (University Hospital Aachen and Charité - University Hospital Berlin). Blood samples were collected pre-surgery (baseline), directly postoperatively and at 12, 24 and 48 hours after surgery. The penKid concentration in plasma was measured using the immunoluminometric sphingotest® assay kit and they were statistically tested for association with AKI and other clinical parameters. Results: Twenty-four patients (62%) developed moderate or severe AKI postoperatively (Stage 2 or 3 of the KDIGO classification) and they had a significantly increased risk for the development of acute respiratory distress syndrome (p=.023) or a fatal outcome (p=.035). Starting from the 12th hour after surgery, we found penKid correlating with AKI stage 2/3 (12 hour penKid mean in pmol/L: 93.9 vs. 43.1; c index .776, p=.0037) and renal replacement therapy (12 hour c index .779, p=.0035). Patients with multi-organ dysfunction syndrome had significantly increased penKid levels at all timepoints. Conclusions: We found penKid to be a promising biomarker for the early detection of postoperative AKI and in-hospital mortality after open TAAA repair, which may enable the early initiation of organ-protective strategies and reduction of further complications associated with AKI.

New Large Animal Model for Aortic Aneurysms in the Viscerorenal Segment.

BACKGROUND: Aortic aneurysms in the viscerorenal-segment are nowadays treatable by endovascular means. Previously, new endograft techniques were only tested in healthy animals. We aimed to establish a new large animal model for testing complex endovascular stent techniques preclinically. METHODS: In sheep, four juxtarenal and two type IV thoracoabdominal aortic aneurysms were surgically created via a retroperitoneal approach. Two pieces out of a 10 × 15-cm bovine pericardial patch were sewn with the healthy aorta longitudinally. The viscerorenal segment was clamped, and the aorta was incised longitudinally. Then, the patches were longitudinally sewn together. In the meantime, antegrade flow through the native part of the aorta was already established by tangential clamping. Computed tomography angiography was performed after 4, 8, and 52 wk. RESULTS: Technical success was 100%. The median surgical procedure time was 3 h, the median blood loss was 210 mL, and the viscerorenal-segment clamping time was 2-4 min. The animals started drinking 1 h after arousal from anesthesia. One animal died after 1 wk because of delayed bleeding and another died after 1 y because of aneurysm rupture by a secondary bacterial infection. Four animals survived. The proximal landing zone diameter and the clock position of the vessel were stable over 52 wk. CONCLUSIONS: Surgical creation of an aortic aneurysm in the viscerorenal-segment in sheep was successful, without an ischemia/reperfusion injury. This animal model offers a new platform for evaluating innovative endovascular therapy options in vivo.