Increased suPAR Plasma Levels May Indicate Postoperative Sepsis Following Open Thoracoabdominal Aortic Repair

<b>Background/Objectives</b>: Postoperative organ complications following open thoracoabdominal aortic aneurysm (TAAA) repair pose significant challenges during the early postoperative period, where prompt detection is crucial for improving patient outcomes. Sepsis is often a central factor in these complications. This study investigates the perioperative dynamics of soluble urokinase plasminogen activator receptor (suPAR) plasma levels in TAAA patients undergoing elective surgical repair and evaluates its diagnostic potential for early detection of postoperative sepsis. <b>Methods</b>: In this retrospective, single-center study, 28 patients (mean age 52.6 ± 13.4 years; 67.9% male) underwent elective open TAAA repair between 2022 and 2024. Blood samples were collected at five perioperative time points, and suPAR levels were measured using ELISA. The primary endpoint was the onset of postoperative sepsis, with secondary endpoints including other organ complications. The predictive performance of suPAR levels was evaluated using Receiver Operator Characteristics (ROC) analysis. <b>Results</b>: Postoperative sepsis developed in 7 of 28 patients (25%), with the diagnostic criteria met at a mean of 9.7 ± 6.9 days. Baseline suPAR levels did not differ between groups; however, from 12 h after surgery, the sepsis group exhibited significantly higher serum concentrations (14.43 ng/mL vs. 7.23 ng/mL; <i>p</i> = 0.004), a difference that persisted throughout the first 24 h. At 24 h, suPAR had the highest predictive accuracy for sepsis, with an AUC of 0.90, 90% sensitivity, and 86% specificity at a 9 ng/mL cut-off (<i>p</i> < 0.001). <b>Conclusions</b>: Elevated suPAR levels in the early postoperative period are strongly associated with the later onset of sepsis. Early monitoring may enable timely intervention, potentially improving outcomes in this high-risk patient population.