Retrospective analysis of incidence, risk factors and clinical outcomes of postoperative complications in 400 renal transplant recipients: a single-center retrospective cohort study with 3-year follow-up

Abstract To investigate the incidence, characteristics, independent risk factors and clinical outcomes of postoperative complications in renal transplant recipients, establish a risk prediction model, and provide evidence for clinical prevention and management. This retrospective cohort study enrolled 400 renal transplant recipients from January 2018 to December 2022 with a 36-month minimum follow-up. Clinical data were collected, and complications were classified into infectious and non-infectious types. Univariate and multivariate logistic regression were used to screen risk factors and construct a nomogram. Survival analysis was performed via Kaplan–Meier curve and Cox regression, with P < 0.05 as statistically significant. 228 (57.0 %) recipients developed complications, 76.3 % infectious and 23.7 % non-infectious. Pneumonia was the most common infectious complication, dominated by Gram-negative bacteria (58.3 %), 30.2 % of which were multidrug-resistant. Advanced age, diabetes, deceased donor transplantation and high-dose tacrolimus were independent risk factors. The nomogram had good predictive efficacy (AUC = 0.782). Complicated recipients had higher rehospitalization rate, longer hospital stay and lower graft survival rates. Postoperative complications were an independent risk factor for 3-year graft loss (HR = 2.84), while severe infectious complications further increased the risk (HR = 4.12). Postoperative complications are highly prevalent in renal transplant recipients, mainly infectious. The identified risk factors are independently associated with reduced graft survival, and the nomogram can effectively predict complication risk to improve recipients’ long-term prognosis.