Impact of postoperative acute kidney injury in patients undergoing major gastrointestinal surgery on 1-year survival and renal outcomes: a national multicentre cohort study

Abstract

Background: The intermediate-term impact of acute kidney injury (AKI) in patients after major gastrointestinal and liver surgery has not been well characterized. This study aimed to evaluate the 1-year mortality rate and renal outcomes associated with postoperative AKI in a national prospective cohort.

Methods: This prospective multicentre, observational cohort with 1-year postoperative follow-up included adults undergoing major gastrointestinal and liver surgery across the UK and Ireland between 23 September and 18 November 2015. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary outcome was death at 1-year after surgery, and the secondary outcome was Major Adverse Kidney Events (MAKE-365). Cox proportionate and multilevel logistic regression were used to account for case mix.

Results: Of 5745 patients across 173 centres, 1-year follow-up data was completed for 3504 patients (62.2 per cent, 126 centres), with attrition largely explained by centre non-participation (63.1 per cent). Some 13.6 per cent (475 of 3504) patients developed AKI by 7 days after surgery (stage 1: 9.2 per cent; stage 2/3: 4.3 per cent). At 1 year, 10.8 per cent (378 patients) experienced a MAKE-365 endpoint (303 patients had died, 61 had renal replacement therapy and 78 had renal dysfunction). Patients who experienced AKI by 7 days after surgery had a higher hazard of death at 1 year for KDIGO stage 1 (hazard ratio 1.50 (95 per cent c.i. 1.08 to 2.08), P = 0.016) and KDIGO stage 2/3 (hazard ratio 2.96 (95 per cent c.i. 2.02 to 4.33), P < 0.001). Both KDIGO stage 1 (odds ratio 2.09 (95 per cent c.i. 1.50 to 2.92), P < 0.001) and stage 2/3 (odds ratio 9.26 (95 per cent c.i. 6.31 to 13.59), P < 0.001) AKI were independently associated with MAKE-365.

Conclusion: AKI events within 7 days after gastrointestinal or liver surgery are associated with significantly worse survival and renal outcomes at 1 year.

Fig. 1

Flow diagram of patient inclusion in 1-year follow-up study from the original Outcomes After Kidney injury in Surgery cohort AKI, acute kidney injury; MAKE, Major Adverse Kidney Events.

Fig. 2

Unadjusted (Kaplan–Meier) and adjusted (extended Cox regression model) survival curves for patient survival from postoperative day 0 to 365, by acute kidney injury (AKI) stage.

Fig. 3

Unadjusted (Kaplan-Meier) and adjusted (Cox regression model) survival curves for patient survival from postoperative day 30 to 365, by acute kidney injury (AKI) stage.

Fig. 4

Venn diagram of patients who had a major adverse kidney event (MAKE-365). RRT, renal replacement therapy.

Fig. 5

Kaplan–Meier plot of the time until first recorded post-discharge serum creatinine, by acute kidney injury (AKI) stage. Patients censored by death or completion of 1-year follow-up Log rank test P = 0.019.