Impact of early postoperative creatinine increase on mid-term renal function after cystectomy

Objectives To determine whether early acute kidney injury affects mid-term renal function, to identify risk factors for impaired mid-term renal function, and to highlight the evolution of plasma creatinine and estimated glomerular filtration rate in the first 12 months after cystectomy and urinary diversion. Methods We conducted a single-center retrospective observational cohort study from 2000 to 2019. We included 900 consecutive patients undergoing cystectomy and urinary diversion. Patients with incomplete data and preoperative hemodialysis were excluded. Early acute kidney injury was defined as an increase in plasma creatinine of >50% or >26.5 mu mol/L within 24 h after surgery. Multiple linear regression analysis was performed to model the association between risk factors and change in plasma creatinine and estimated glomerular filtration rate at 12 months. Results Early acute kidney injury was diagnosed in 183/900 patients (20.3%) and was associated with significant mid-term plasma creatinine increase compared to preoperative value (+10.0 mu mol/L [95% confidence interval -1.5, 25.0] vs +4.0 mu mol/L [-7.0, 13.0]; P < 0.001). Similarly, a significant estimated glomerular filtration rate change was found (-11.2 mL/min [95% confidence interval -19.8, 0.6] vs -4.9 mL/min [-15.6, 5.3]; P < 0.001). In the linear regression model, early acute kidney injury increased creatinine at 12 months by 9.8% (estimated glomerular filtration rate: decrease by 6.2 mL/min), male sex by 12.0%. Limitations include retrospective analysis from prospectively assessed data. Conclusions Early acute kidney injury resulted in elevated plasma creatinine and decreased estimated glomerular filtration rate values 12 months postoperatively, albeit the clinical relevance remains questionable.