Risk factors for postoperative acute kidney injury after radical cystectomy for bladder cancer in the era of ERAS protocols: A retrospective observational study.

Background: Radical cystectomy (RC) is a major surgery associated with a high morbidity rate. Perioperative fluid management according to enhanced recovery after surgery (ERAS) protocols aims to maintain patients in an optimal euvolemic state while exposing them to acute kidney injury (AKI) in the event of hypovolemia. Postoperative AKI is associated with severe morbidity and mortality. Our main objective was to determine the association between perioperative variables, including some component of ERAS protocols, and occurrence of postoperative AKI within the first 30 days following RC in patients presenting bladder cancer. Our secondary objective was to evaluate the association between a postoperative AKI and the occurrence or worsening of a chronic kidney disease (CKD) within the 2 years following RC.

Methods: We conducted a retrospective observational study in a referral cancer center in France on 122 patients who underwent an elective RC for bladder cancer from 01/02/2015 to 30/09/2019. The primary endpoint was occurrence of AKI between surgery and day 30. The secondary endpoint was survival without occurrence or worsening of a postoperative CKD. AKI and CKD were defined by KDIGO (Kidney Disease: Improving Global Outcomes) classification. Logistic regression analyse was used to determine independent factors associated with postoperative AKI. Fine and Gray model was used to determine independent factors associated with postoperative CKD.

Results: The incidence of postoperative AKI was 58,2% (n = 71). Multivariate analysis showed 5 factors independently associated with postoperative AKI: intraoperative restrictive vascular filling < 5ml/kg/h (OR = 4.39, 95%CI (1.05-18.39), p = 0.043), postoperative sepsis (OR = 4.61, 95%CI (1.05-20.28), p = 0.043), female sex (OR = 0.11, 95%CI (0.02-0.73), p = 0.022), score SOFA (Sequential Organ Failure Assessment) at day 1 (OR = 2.19, 95%CI (1.15-4.19), p = 0.018) and delta serum creatinine D1 (OR = 1.06, 95%CI (1.02-1.11), p = 0.006). During the entire follow-up, occurrence or worsening of CKD was diagnosed in 36 (29.5%). A postoperative, AKI was strongly associated with occurrence or worsening of a CKD within the 2 years following RC even after adjustment for confounding factors (sHR = 2.247, 95%CI [1.051-4.806, p = 0.037]).

Conclusion: A restrictive intraoperative vascular filling < 5ml/kg/h was strongly and independently associated with the occurrence of postoperative AKI after RC in cancer bladder patients. In this context, postoperative AKI was strongly associated with the occurrence or worsening of CKD within the 2 years following RC. A personalized perioperative fluid management strategy needs to be evaluated in these high-risk patients.