Early plasma syndecan-1 dynamics and their prognostic value in major thoracic and abdominal surgery: a prospective observational study

BACKGROUND: Glycocalyx degradation, reflected by syndecan-1 shedding, is implicated in microcirculatory dysfunction and inflammatory responses. The present study aimed to assess early postoperative changes in plasma syndecan-1 levels following major thoracic and abdominal surgery, and their association with 30-days postoperative complications. METHODS: A prospective, single-center observational cohort study included 107 patients. Syndecan-1 levels were measured preoperatively and two and 18 h after surgery. Associations with clinical and intraoperative variables were evaluated using univariate linear regression. The predictive performance of syndecan-1 for major complications and mortality within 30 days was assessed via receiver operating characteristic (ROC) analysis. RESULTS: The median syndecan-1 values after two hours of surgery were 958 pg/mL (IQR 654–2665). No significant associations were found with comorbidities, surgical approach, intraoperative factors, or complications (all p > 0.05). Syndecan-1 showed poor predictive performance for major complications and mortality within 30 days (AUC 0.52; 95% CI: 0.40–0.63; p = 0.765). CONCLUSION: Syndecan-1 levels vary widely postoperatively and are not associated with key perioperative variables or outcomes. These findings suggest limited utility of syndecan-1 as a biomarker for perioperative risk stratification in this setting.