Composite inflammatory biomarkers for predicting vascular crisis after finger replantation: a two-center retrospective study identifying a promising inflammatory biomarker and its multidimensional evaluation.

BACKGROUND

Vascular crisis is a leading cause of replantation failure following finger replantation, and preoperative identification of high-risk patients is essential for improving clinical outcomes. Composite inflammatory biomarkers derived from routine blood tests have demonstrated predictive value across multiple surgical disciplines; however, their role in predicting vascular crisis after finger replantation has not been systematically evaluated.

METHODS

This retrospective study enrolled 1, 744 patients who underwent finger replantation, classified into a vascular crisis group (n = 102) and a non-vascular crisis group (n = 1, 642). Eight preoperative composite inflammatory biomarkers were calculated, including SIRI, NPAR, AISI, NLR, SII, MLR, NPR, and PLR. Three stepwise-adjusted logistic regression models were constructed, and the optimal biomarker was identified through ROC curve analysis. Subsequent analyses included restricted cubic spline (RCS) modeling, threshold effect analysis, subgroup analysis, mediation analysis, and multinomial logistic regression. Propensity score matching (PSM) with mixed-effects logistic regression was performed for validation.

RESULTS

The overall incidence of vascular crisis was 5.85%. In the fully adjusted model, the highest tertile groups of SIRI, NPAR, AISI, NLR, SII, and NPR were significantly associated with increased vascular crisis risk (all P < 0.050). SIRI demonstrated the highest discriminative ability (AUC = 0.695), with an optimal cutpoint of 1.214. RCS analysis revealed a nonlinear association between SIRI and vascular crisis (P-nonlinear < 0.001), with a breakpoint at 3.388, below which each unit increase in SIRI was significantly associated with elevated risk (adjusted OR = 2.00, 95% CI: 1.45 to 2.77, P < 0.001). Subgroup analysis demonstrated a stronger predictive effect among smokers (P for interaction = 0.018). D-dimer partially mediated the SIRI-vascular crisis association (mediated proportion 10.00%). SIRI exhibited more robust predictive performance for venous than arterial crisis. PSM validation confirmed significantly elevated risk in the high SIRI group (OR = 2.65, 95% CI: 1.81 to 3.88, P < 0.001).

CONCLUSION

Preoperative SIRI was significantly associated with vascular crisis following finger replantation and showed the highest numerical AUC among the tested composite inflammatory biomarkers. SIRI may serve as a supplementary tool for perioperative risk stratification and warrants further validation in two-center prospective studies.