Perioperative factors associated with acute kidney injury after partial nephrectomy

Laparoscopic partial versus radical nephrectomy for localized renal cell carcinoma over 4 cm

PURPOSE

To compare the long-term clinical and oncologic outcomes of laparoscopic partial nephrectomy (LPN) and laparoscopic radical nephrectomy (LRN) in patients with renal cell carcinoma (RCC) > 4 cm.

METHODS

We retrospectively reviewed the records of all patients who underwent LPN or LRN in our department from January 2012 to December 2017. Of the 151 patients who met the study selection criteria, 54 received LPN, and 97 received LRN. After propensity-score matching, 51 matched pairs were further analyzed. Data on patients' surgical data, complications, histologic data, renal function, and survival outcomes were collected and analyzed.

RESULTS

Compared with the LRN group, the LPN group had a longer operative time (135 min vs. 102.5 min, p = 0.001), larger intraoperative bleeding (150 ml vs. 50 ml, p < 0.001), and required longer stays in hospital (8 days vs. 6 days, p < 0.001); however, the level of ECT-GFR was superior at 3, 6, and 12 months (all p < 0.001). Similarly, a greater number of LRN patients developed CKD compared with LPN until postoperative 12 months (58.8% vs. 19.6%, p < 0.001). In patients with preoperative CKD, LPN may delay the progression of the CKD stage and even improve it when compared to LRN treatment. There were no significant differences between the two groups for OS, CSS, MFS, and PFS (p = 0.06, p = 0.30, p = 0.90, p = 0.31, respectively). The surgical method may not be a risk factor for long-term survival prognosis.

CONCLUSION

LPN preserves renal function better than LRN and has the potential value of significantly reducing the risk of postoperative CKD, but the long-term survival prognosis of patients is comparable.

The Association of Ischemia Type and Duration with Acute Kidney Injury after Robot-Assisted Partial Nephrectomy

BACKGROUND

Acute kidney injury (AKI) after robot-assisted partial nephrectomy (RAPN) is a robust surrogate for chronic kidney disease. The objective of this study was to evaluate the association of ischemia type and duration during RAPN with postoperative AKI.

MATERIALS AND METHODS

We reviewed all patients who underwent RAPN at our institution since 2011. The ischemia types were warm ischemia (WI), selective artery clamping (SAC), and zero ischemia (ZI). AKI was defined according to the Risk Injury Failure Loss End-Stage (RIFLE) criteria. We calculated ischemia time thresholds for WI and SAC using the Youden and Liu indices. Logistic regression and decision curve analyses were assessed to examine the association with AKI.

RESULTS

Overall, 154 patients met the inclusion criteria. Among all RAPNs, 90 (58.4%), 43 (28.0%), and 21 (13.6%) were performed with WI, SAC, and ZI, respectively. Thirty-three (21.4%) patients experienced postoperative AKI. We extrapolated ischemia time thresholds of 17 min for WI and 29 min for SAC associated with the occurrence of postoperative AKI. Multivariable logistic regression analyses revealed that WIT ≤ 17 min (odds ratio [OR] 0.1, p < 0.001), SAC ≤ 29 min (OR 0.12, p = 0.002), and ZI (OR 0.1, p = 0.035) significantly reduced the risk of postoperative AKI.

CONCLUSIONS

Our results confirm the commonly accepted 20 min threshold for WI time, suggest less than 30 min ischemia time when using SAC, and support a ZI approach if safely performable to reduce the risk of postoperative AKI. Selecting an appropriate ischemia type for patients undergoing RAPN can improve short- and long-term functional kidney outcomes.

Prediction of Postoperative Creatinine Levels by Artificial Intelligence after Partial Nephrectomy

Background and Objectives: Multiple factors are associated with postoperative functional outcomes, such as acute kidney injury (AKI), following partial nephrectomy (PN). The pre-, peri-, and postoperative factors are heavily intertwined and change dynamically, making it difficult to predict postoperative renal function. Therefore, we aimed to build an artificial intelligence (AI) model that utilizes perioperative factors to predict residual renal function and incidence of AKI following PN. Methods and Materials: This retrospective study included 785 patients (training set 706, test set 79) from six tertiary referral centers who underwent open or robotic PN. Forty-four perioperative features were used as inputs to train the AI prediction model. XG-Boost and genetic algorithms were used for the final model selection and to determine feature importance. The primary outcome measure was immediate postoperative serum creatinine (Cr) level. The secondary outcome was the incidence of AKI (estimated glomerular filtration rate (eGFR) < 60 mL/h). The average difference between the true and predicted serum Cr levels was considered the mean absolute error (MAE) and was used as a model evaluation parameter. Results: An AI model for predicting immediate postoperative serum Cr levels was selected from 2000 candidates by providing the lowest MAE (0.03 mg/dL). The model-predicted immediate postoperative serum Cr levels correlated closely with the measured values (R2 = 0.9669). The sensitivity and specificity of the model for predicting AKI were 85.5% and 99.7% in the training set, and 100.0% and 100.0% in the test set, respectively. The limitations of this study included its retrospective design. Conclusions: Our AI model successfully predicted accurate serum Cr levels and the likelihood of AKI. The accuracy of our model suggests that personalized guidelines to optimize multidisciplinary plans involving pre- and postoperative care need to be developed.

Acute kidney injury as an independent predicting factor for stage 3 or higher chronic kidney disease after nephrectomy

BACKGROUND

The association between postoperative acute kidney injury (AKI) and long-term renal function after nephrectomy has not been fully explored, with accurate prognostic models in which AKI is an independent predicting variable still being absent.

METHODS

We conducted a retrospective study of 528 patients who underwent unilateral radical nephrectomy or partial nephrectomy owing to renal cell carcinoma between January 2013 and December 2016. Postoperative AKI was defined as an absolute increase in serum creatinine level by 0.3 mg/dl or ≥5 0% increase from the preoperative value within 48 hours after surgery. The endpoint was the time to the incident stage 3 or higher chronic kidney disease (defined as eGFR<60 ml/min/1.73m²), or any claim for initiation of dialysis. Cox proportional hazards regression analysis was conducted to construct the final model. Internal validation was performed using 10-fold cross-validation. The model was evaluated in discrimination by Harrell's C-index and area under curve (AUC) values, and calibration by calibration plots.

RESULTS

Five hundred twenty-eight patients were finally enrolled in the study cohort, and the median follow-up period was 38 months. Among 528 admitted patients, 232 (43.9%) developed AKI, and stage 3 or higher CKD occurred in 47 (8.9%) patients during the follow-up time, with 33 in 47 patients (70.2%) having postoperative AKI. AKI was significantly correlated with poor prognosis of renal function (HR = 3.079, P < 0.001). After the adjustment of conventional predictors, AKI was still independently related to kidney function deterioration, and the correlation was influenced by the severity of AKI. Five variables were selected to establish the prognostic model, including age, surgery type, preoperative estimated glomerular filtration rate, preoperative blood urea nitrogen, and postoperative AKI. The model had good discrimination, with the Harrell's C-index of 0.92 (95% CI 0.89-0.95), and AUC values varying from 87.7 to 95.7 at different time points.

CONCLUSIONS

AKI during the perioperative period is an independent predicting factor of stage 3 or higher CKD after nephrectomy.

The association between modifiable perioperative parameters and renal function after nephrectomy

OBJECTIVE

To evaluate the association between intraoperative anaesthetic parameters, primarily intraoperative hypotension, and postoperative renal function in patients undergoing nephrectomy.

PATIENTS AND METHODS

We reviewed data from 3240 consecutive patients who underwent nephrectomy between 2010 and 2018. Anaesthetic parameters evaluated included duration of hypotension, tachycardia, hypothermia, volatile anaesthetic use and mean arterial pressure in the post-anaesthesia care unit. Outcomes included acute kidney injury (AKI) and estimated glomerular filtration rate (eGFR) within the first year after nephrectomy. Associations between anaesthetic parameters and outcomes were evaluated with multivariable logistic regression and generalised estimating equation, respectively, adjusted for predictors of renal function after nephrectomy.

RESULTS

Before nephrectomy, 677 (21%) patients had moderate-severe chronic kidney disease. A quarter of patients (n = 809) had postoperative AKI and 35% (n = 746) had Stage ≥3 chronic kidney disease 12-months after surgery. Only 12% of patients (n = 386) had >5 min of intraoperative hypotension. While not statistically significant, longer duration of intraoperative hypotension was associated with slightly higher rates of AKI (odds ratio [OR] per 10-min 1.14, 95% confidence interval [CI] 0.98, 1.32). Prolonged hypothermia was associated with increased rate of AKI (OR per 10-min 1.02, 95% CI 1.00, 1.04), and decreased eGFR (change in eGFR per 10-min -0.19, 95% CI -0.27, -0.12); however, these results have limited clinical significance.

CONCLUSIONS

Under current practice, intraoperative anaesthetic parameters are tightly maintained, restricting the significance of their effect on postoperative renal function. Future studies should evaluate whether haemodynamic parameters during the early postoperative period, when they are monitored less frequently, are associated with renal functional outcome.

The utility of laparoscopic partial nephrectomy with renal function preservation, regardless of warm ischemia time, compared with laparoscopic radical nephrectomy

INTRODUCTION

This study aimed to evaluate the chronologic changes in renal function after laparoscopic partial (LPN) or radical nephrectomy (LRN) in patients with clinical T1 renal cell carcinoma.

METHODS

In this retrospective study, patients with clinical stage T1 renal cell carcinoma who underwent LPN or LRN were divided into three groups, namely, LPN-A group including LPN patients with WIT ≤25 minutes, LPN-B group including LPN patients with WIT >25 minutes, and LRN group. Perioperative complications that occurred within 30 days after surgery were retrieved. All patients were followed-up every 3 months to evaluate the estimated glomerular filtration rate. The primary endpoint of this study was to assess the chronological changes in renal function after surgery.

RESULTS

A total of 153 patients were enrolled in this study. The change in estimated glomerular filtration rate between day 1 and 2 weeks after surgery was significantly lower in the LPN-B group than in the LPN-A group (p<0.005). Both LPN-A and -B groups achieved eGFR ≥90% 2 weeks after surgery. In addition, the estimated glomerular filtration rate decline from post-operative day 1 through 24 months in the LPN-A group or the LPN-B group was significantly smaller than that in the LRN group (P < 0.001, P < 0.001, respectively).

CONCLUSION

Our results demonstrate the efficacy and safety of LPN in patients with T1 renal cell carcinoma. Although complication rates were similar in both groups, post-operative renal function was not different between the LPN-A and -B groups.

Impact of goal-directed hemodynamic management on the incidence of acute kidney injury in patients undergoing partial nephrectomy: a pilot randomized controlled trial

Background

The incidence of acute kidney injury (AKI) remains high after partial nephrectomy. Ischemia-reperfusion injury produced by renal hilum clamping during surgery might have contributed to the development of AKI. In this study we tested the hypothesis that goal-directed fluid and blood pressure management may reduce AKI in patients following partial nephrectomy.

Methods

This was a pilot randomized controlled trial. Adult patients who were scheduled to undergo partial nephrectomy were randomized into two groups. In the intervention group, goal-directed hemodynamic management was performed from renal hilum clamping until end of surgery; the target was to maintain stroke volume variation < 6%, cardiac index 3.0–4.0 L/min/m² and mean arterial pressure > 95 mmHg with crystalloid fluids and infusion of dobutamine and/or norepinephrine. In the control group, hemodynamic management was performed according to routine practice. The primary outcome was the incidence of AKI within the first 3 postoperative days.

Results

From June 2016 to January 2017, 144 patients were enrolled and randomized (intervention group, n = 72; control group, n = 72). AKI developed in 12.5% of patients in the intervention group and in 20.8% of patients in the control group; the relative reduction of AKI was 39.9% in the intervention group but the difference was not statistically significant (relative risk 0.60, 95% confidence interval [CI] 0.28–1.28; P = 0.180). No significant differences were found regarding AKI classification, change of estimated glomerular filtration rate over time, incidence of postoperative 30-day complications, postoperative length of hospital stay, as well as 30-day and 6-month mortality between the two groups.

Conclusion

For patients undergoing partial nephrectomy, goal-directed circulatory management during surgery reduced postoperative AKI by about 40%, although not significantly so. The trial was underpowered. Large sample size randomized trials are needed to confirm our results.

Trial registration

Clinicaltrials.gov identifier: NCT02803372. Date of registration: June 6, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01288-8.

Identifying the predictors of estimated glomerular filtration rate after partial nephrectomy with a nonlinear regression model

PURPOSE

To evaluate the effect of partial nephrectomy on renal function and to identify predictors of estimated glomerular filtration rate (eGFR) at 6 months after partial nephrectomy.

METHODS

Medical data of 154 consecutive patients who underwent partial nephrectomy for a renal mass between January 2015 and March 2020 were retrospectively analysed. The primary outcome measure was eGFR at 6 months postoperatively. An ordinary least regression analysis using a restricted cubic spline for continuous variables was performed to examine the association between primary outcome measure and candidate predictors.

RESULTS

Of the patients, 66 (42.9%) were females and 88 (57.1%) were males with a median age of 60 (range, 50 to 67) years. The median baseline eGFR was 90.40 (range, 74.96 to 102.97) mL/min/1.73 m² , while the median eGFR at 6 months was 77.12 (range, 61.06 to 91.93) mL/min/1.73 m² (P < .001). Baseline eGFR (regression coefficient (β) = 22.7, 95%CI: 18.8 to 26.5, P < .001) was found to be most significant predictor with the postoperative eGFR levels at 6 months. In addition, advanced tumour size (β = -3.17, 95%CI: -5.33 to -1.01, P < .001) and presence of hypertension (β = -3.48, 95%CI: -6.96 to -0.003, P = .049) were also found to be inversely associated with the postoperative eGFR levels at 6 months.

CONCLUSION

Baseline eGFR values, tumour size, and presence of hypertension are significant predictors of eGFR values in the mid-term in patients undergoing partial nephrectomy.

Postoperative acute kidney injury in adult non-cardiac surgery: joint consensus report of the Acute Disease Quality Initiative and PeriOperative Quality Initiative

Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes, including increased risk of chronic kidney disease, cardiovascular events and death. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. PO-AKI is best defined as AKI occurring within 7 days of an operative intervention using the Kidney Disease Improving Global Outcomes (KDIGO) definition of AKI; however, additional prognostic information may be gained from detailed clinical assessment and other diagnostic investigations in the form of a focused kidney health assessment (KHA). Prevention of PO-AKI is largely based on identification of high baseline risk, monitoring and reduction of nephrotoxic insults, whereas treatment involves the application of a bundle of interventions to avoid secondary kidney injury and mitigate the severity of AKI. As PO-AKI is strongly associated with long-term adverse outcomes, some form of follow-up KHA is essential; however, the form and location of this will be dictated by the nature and severity of the AKI. In this Consensus Statement, we provide graded recommendations for AKI after non-cardiac surgery and highlight priorities for future research.

Hydroxyethyl Starch 6% 130/0.4 in a Balanced Electrolyte Solution and Renal Function After Nephrectomy

BACKGROUND

Although previous studies have reported nephrotoxicity associated with hydroxyethyl starch (HES), the long-term effect of HES on renal function after nephrectomy has rarely been reported. We evaluated the association between intraoperative HES administration and short- and long-term renal function after nephrectomy.

METHODS

We retrospectively reviewed 1106 patients who underwent partial or radical nephrectomy. The patients were divided into 2 groups: patients who received (HES group) or did not receive 6% HES 130/0.4 intraoperatively (non-HES group). The primary outcome was new-onset chronic kidney disease (CKD) stage 3a (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m) or higher or all-cause mortality during 60 months after surgery. Propensity score matching was performed to address baseline differences between the 2 groups. Renal survival determined by stage 3a and stage 5 CKD (eGFR <15 mL/min/1.73 m) or all-cause mortality were compared up to 60 months before and after matching. We compared postoperative acute kidney injury (AKI) and CKD upstaging in the matched cohort as secondary outcomes. Ordinal logistic regression and Cox proportional hazards regression analyses using inverse probability of treatment weighting were performed for postoperative AKI and our primary outcome, respectively. A subgroup analysis of partial nephrectomy was performed.

RESULTS

Thirty percent of patients received HES intraoperatively. Balanced solution and 0.9% normal saline was administered during surgery in both groups. Renal survival was not significantly different between groups after matching (log-rank test P = .377 for our primary outcome, and P = .981 for stage 5 or all-cause mortality, respectively). In the matched cohort (HES group: n = 280, non-HES group: n = 280), the incidence of AKI or CKD upstaging at 1 year was not significantly different (AKI: n = 94, 33.6% in HES group versus n = 90, 32.1% in non-HES group; CKD upstaging: n = 132, 47.1% in HES group versus n = 122, 43.6% in non-HES group; odds ratio [OR], 1.16; 95% confidence interval [CI], 0.83-1.61; P = .396). Intraoperative HES administration was not associated with postoperative renal outcomes (AKI: OR, 0.97; 95% CI, 0.81-1.16; P = .723; CKD stage 3a or higher or all-cause mortality: hazard ratio, 1.01; 95% CI, 0.89-1.14; P = .920). Subgroup analysis yielded similar results.

CONCLUSIONS

Intraoperative 6% HES 130/0.4 administration was not significantly associated with short- and long-term renal function or renal survival up to 5 years in patients undergoing partial or radical nephrectomy. However, wide CI including large harm effect precludes firm conclusion and inadequate assessment of safety cannot be ruled out by our results.

Acute kidney injury in solitary kidney patients after partial nephrectomy: incidence, risk factors and prediction

Background

To analyze the incidence and risk factors of acute kidney injury (AKI) after partial nephrectomy (PN) in patients with solitary kidney, and to build AKI prediction models using logistic regression and machine learning (ML) approaches.

Methods

Clinical data of 87 solitary kidney patients with renal mass who received PN from January 2003 to March 2019 were collected. The diagnosis of AKI was based on KDIGO criteria. Logistic regression analysis and ML method were used to build prediction models.

Results

AKI developed in 52 (59.8%) patients. The logistic regression model had three variables: ischemia time (P=0.003), surgery time (P=0.001) and preoperative fasted blood glucose level (FBG) (P=0.049). The area under curve (AUC) was 0.826, with the specificity and sensitivity of optimal threshold value 82.9% and 69.2%. The ML model had the following variables: ischemia time, surgery time, age, FBG, mean arterial pressure (MAP), colloid, crystalloid, etc. XGBoost model has the best prediction performance. The AUC was 0.749, lower than that of the logistic regression model with no statistical difference (P=0.258), with the specificity and sensitivity 62.9% and 84.6%, respectively.

Conclusions

The incidence of AKI after PN in patients with a solitary kidney was relatively high, it was associated with longer ischemia time, surgery time and higher FBG level, etc. The performance of ML model had no significant difference with logistic regression model. Prospective studies with larger sample sizes are awaited to test and verify our research findings.

Toward Individualized Approaches to Partial Nephrectomy: Assessing the Correlation Between Ischemia Time and Patient Health Status (RECORD2 Project)

BACKGROUND

Ischemia time during partial nephrectomy (PN) is among the greatest determinants of acute kidney injury (AKI). Whether this association is affected by the preoperative risk of AKI has never been investigated.

OBJECTIVE

To assess the effect of the interaction between the preoperative risk of AKI and ischemia time on the probability of AKI during PN.

DESIGN, SETTING, AND PARTICIPANTS

Data of 944 patients treated with on-clamp PN for cT1 renal tumors were extracted from the Registry of Conservative and Radical Surgery for Cortical Renal Tumor Disease (RECORD2) database, a prospective multicenter project.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We estimated the preoperative risk of AKI (defined according to the risk/injury/failure/loss/end-stage [RIFLE] criteria) according to age, baseline renal function, clinical stage, preoperative aspects and dimensions used for an anatomical (PADUA) score, and surgical approach. Classification and regression tree (CART) analysis identified patients at "high" and "low" risk of AKI. Finally, we plotted the probability of AKI over ischemia time stratified by the preoperative risk of AKI.

RESULTS AND LIMITATIONS

Overall, 235 (25%) patients experienced AKI after surgery. At multivariable analysis, older patients, those with more complex tumors, those with higher baseline function, and those treated with open surgery had an increased risk of AKI (all p ≤ 0.011). According to the first split at CART analysis, patients were categorized as those with "high" and "low" risk of AKI having a probability of >40% or <40%. For low-risk patients, the probability of AKI in case of <10 versus >20 min of ischemia was 13% versus 28% (absolute risk increase 15%). The risk of AKI for high-risk patients who had <10 versus >20 min of ischemia was 31% versus 77%. This corresponds to an absolute risk increase of 45%. Limitations include retrospective data analyses and lack of surgeons' prior experience.

CONCLUSIONS

Ischemia time during PN has different implications for patients with different health status. Clamp time seems less clinically relevant for patients in good conditions who may endure prolonged ischemia with a mild increase in the risk of AKI, whereas frail patients seem to be more vulnerable to ischemic damage even for short clamp time. For individualized intra- and postoperative management, duration of ischemia needs to be questioned in the context of the individual health status.

PATIENT SUMMARY

Functional sequelae related to ischemia time during partial nephrectomy depend on baseline health status. The correlation between the duration of ischemia and baseline health status should be taken into account toward individualized intra- and postoperative management.

Endovascular Aspiration Thrombectomy in the Management of Kidney Ischemia: A Case Report

Renal artery occlusion is a serious event that can result in significant impairment or loss of renal function, leading to dialysis dependency. The nonspecific signs and symptoms of its presentation frequently result in a delay in diagnosis, thus contributing to delay in treatment. We report the case of a 53-year old woman who suffered renal artery occlusion, in which the renal perfusion was restored after three days of ischemia, by endovascular aspiration thrombectomy.

Development of a risk scoring system for predicting acute kidney injury after minimally invasive partial and radical nephrectomy: a retrospective study

BACKGROUND

Acute kidney injury after partial or radical nephrectomy remains an unsolved problem even when using minimally invasive techniques. We aimed to identify risk factors for acute kidney injury (AKI) after minimally invasive nephrectomy and to develop a clinical risk scoring system.

METHODS

Medical records of 1762 patients who underwent minimally invasive laparoscopic or robot-assisted laparoscopic partial (n = 1009) or radical (n = 753) nephrectomy from December 2005 to November 2018 were reviewed. Candidate risk factors were screened using univariate analysis and ranked using linear discriminant analysis; top ranking factors were incorporated into a multivariate logistic regression model. Then, the final clinical scoring system was created based on the estimated odds ratios.

RESULTS

The incidence of acute kidney injury after partial or radical nephrectomy was 20.3 and 61.6%, respectively. Risk factors incorporated into the scoring system included: size of the parenchymal mass removed (3 < parenchymal mass ≤ 4 cm, 1 point; 4 < parenchymal mass ≤ 6 cm, 3 points; parenchymal mass > 6 cm, 5 points), male sex (2 points), diabetes mellitus (1 point), warm ischemia time ≥ 25 min (1 point), and immediate postoperative neutrophil count ≥ 12,000 µl^-1 (1 point) in patients with partial nephrectomy, and sex (male, 10 points; female, 7 points) in patients with radical nephrectomy. For risk scores of 0-4, 5-6, 7, 8-9, and 10 points, the probabilities of acute kidney injury were approximately 10, 20, 40, 60, and 80%, respectively. The predictive accuracy of the scoring system was 0.827 (95% CI 0.789-0.865).

CONCLUSION

Our risk scoring system could help clinicians identify those at risk of acute kidney injury after minimally invasive partial or radical nephrectomy, thereby optimizing postoperative management.

Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy

Purpose

We investigated the association between preoperative proteinuria and early postoperative renal function after robotic partial nephrectomy (RPN).

Patients and Methods

We retrospectively reviewed 1121 consecutive RPN cases at a single academic center from 2006 to 2016. Patients without pre-existing CKD (eGFR≥60 mL/min/1.73m²) who had a urinalysis within 1-month prior to RPN were included. The cohort was categorized by the presence or absence of preoperative proteinuria (trace or greater (≥1+) urine dipstick), and groups were compared in terms of clinical and functional outcomes. The incidence of acute kidney injury (AKI) was assessed using RIFLE criteria. Univariate and multivariable models were used to identify factors associated with postoperative AKI.

Results

Of 947 patients, 97 (10.5%) had preoperative proteinuria. Characteristics associated with preoperative proteinuria included non-white race (p<0.01), preoperative diabetes (p<0.01) and hypertension (HTN) (p<0.01), higher ASA (p<0.01), higher BMI (p<0.01), and higher Charlson score (p<0.01). The incidence of AKI was higher in patients with preoperative proteinuria (10.3% vs. 4.6%, p=0.01). The median eGFR preservation measured within one month after surgery was lower (83.6% vs. 91%, p=0.04) in those with proteinuria; however, there were no significant differences by 3 months after surgery or last follow-up visit. Independent predictors of AKI were high BMI (p<0.01), longer ischemia time (p<0.01), and preoperative proteinuria (p=0.04).

Conclusion

Preoperative proteinuria by urine dipstick is an independent predictor of postoperative AKI after RPN. This test may be used to identify patients, especially those without overt CKD, who are at increased risk for developing AKI after RPN.

General Anesthetic Agents and Renal Function after Nephrectomy

The association between the choice of general anesthetic agents and the risk of acute kidney injury (AKI) and long-term renal dysfunction after nephrectomy has not yet been evaluated. We reviewed 1087 cases of partial or radical nephrectomy. The incidence of postoperative AKI, new-onset chronic kidney disease (CKD) and CKD upstaging were compared between general anesthetic agent groups (propofol, sevoflurane, and desflurane). Four different propensity score analyses were performed to minimize confounding for each pair of comparison (propofol vs. sevoflurane; propofol vs. desflurane; sevoflurane vs. desflurane; propofol vs. volatile agents). Study outcomes were compared before and after matching. Kaplan-Meier survival curve analysis was performed to compare renal survival determined by the development of new-onset CKD between groups up to 36 months after nephrectomy. Propofol was associated with a lower incidence of AKI (propofol 23.2% vs. sevoflurane 39.5%, p = 0.004; vs. propofol 21.0% vs. desflurane 34.3%, p = 0.031), a lower incidence of CKD upstaging (propofol 27.2% vs. sevoflurane 58.4%, p < 0.001; propofol 32.4% vs. desflurane 48.6%, p = 0.017) and better three-year renal survival after nephrectomy compared to sevoflurane or desflurane group (Log-rank test propofol vs. sevoflurane p < 0.001; vs. desflurane p = 0.015) after matching. Propofol was also associated with a lower incidence of new-onset CKD after nephrectomy compared to sevoflurane after matching (p < 0.001). There were no significant differences between sevoflurane and desflurane. However, subgroup analysis of partial nephrectomy showed a significant difference only in CKD upstaging. In conclusion, propofol, compared to volatile agents, could be a better general anesthetic agent for nephrectomy to attenuate postoperative renal dysfunction. However, limitations of the retrospective study design and inconsistent results of the subgroup analysis preclude firm conclusions.

Acute Kidney Injury Adjusted for Parenchymal Mass Reduction and Long-Term Renal Function after Partial Nephrectomy

We sought to evaluate the association of postoperative acute kidney injury (AKI) adjusted for parenchymal mass reduction with long-term renal function in patients undergoing partial nephrectomy. A total of 629 patients undergoing partial nephrectomy were reviewed. Postoperative AKI was defined by the Kidney Disease: Improving Global Outcomes (KDIGO) serum creatinine criteria, by using either the unadjusted or adjusted baseline serum creatinine level, accounting for renal parenchymal mass reduction. Estimated glomerular filtration rates (eGFRs) were followed up to 61 months (median 28 months) after surgery. The primary outcome was the functional change ratio (FCR) of eGFR calculated by the ratio of the most recent follow-up value, at least 24 months after surgery, to eGFR at 3-12 months after surgery. Multivariable linear regression analysis was performed to evaluate whether unadjusted or adjusted AKI was an independent predictor of FCR. As a sensitivity analysis, functional recovery at 3-12 months after surgery compared to the preoperative baseline was analyzed. Median parenchymal mass reduction was 11%. Unadjusted AKI occurred in 16.5% (104/625) and adjusted AKI occurred in 8.6% (54/629). AKI using adjusted baseline creatinine was significantly associated with a long-term FCR (β = -0.129 ± 0.026, p < 0.001), while unadjusted AKI was not. Adjusted AKI was also a significant predictor of functional recovery (β = -0.243 ± 0.106, p = 0.023), while unadjusted AKI was not. AKI adjusted for the parenchymal mass reduction was significantly associated with a long-term functional decline after partial nephrectomy. A creatinine increase due to remaining parenchymal ischemic injury may be important in order to predict long-term renal functional outcomes after partial nephrectomy.

Impact of Acute Kidney Injury and Its Duration on Long-term Renal Function After Partial Nephrectomy

BACKGROUND

The relationship between acute kidney injury (AKI) and long-term renal function is controversial. The influence of AKI duration on functional recovery after partial nephrectomy has never been investigated.

OBJECTIVE

To investigate the association between AKI and renal function 1yr after partial nephrectomy, and whether this relationship is affected by the duration of AKI.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed the data of 1893 patients treated by partial nephrectomy for a single cT1 N0 M0 renal mass.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We defined three outcomes of interest: (1) recovery of at least 90% of baseline function 1yr after partial nephrectomy, (2) percentage change of 1-yr renal function compared with baseline function, and (3) chronic kidney disease (CKD) upstaging. AKI was defined according to the RIFLE criteria and recorded up to the 7th postoperative day. The association between AKI and each endpoint of interest was examined using regression models after adjustment for common predictors of renal function.

RESULTS AND LIMITATIONS

A total of 388 (20%) patients experienced AKI after surgery. The rate of patients recovering 90% of baseline function was lower in the AKI group (30% vs 61%), while the proportion of patients who had CKD upstaging was significantly higher (51% vs 23%; both p<0.0001). At multivariable analysis, AKI was associated with worse renal function 1yr after partial nephrectomy, regardless of the outcome of interest (all p<0.0001). Longer AKI increases the risk of functional deterioration, especially after the 3rd day of injury. The risk of CKD upstaging for an average patient who had 1-3 versus ≥4 d of AKI was 46% (95% confidence interval [CI]: 40%, 52%) versus 67% (95% CI: 55%, 78%; absolute risk increase of 21%; 95% CI: 8%, 34%).

CONCLUSIONS

AKI negatively affects long-term functional recovery after partial nephrectomy, and thus, modifiable factors associated with AKI should be identified and corrected preoperatively. The duration of injury is informative, and should be included in the assessment of AKI and in future studies addressing this topic.

PATIENT SUMMARY

Proper functional recovery after partial nephrectomy is jeopardized by acute kidney injury (AKI). Inclusion of the dimension of time into classification systems for AKI may be beneficial for postoperative risk stratification.

Predicting acute kidney injury after robot-assisted partial nephrectomy: Implications for patient selection and postoperative management

BACKGROUND

Acute Kidney Injury (AKI) is a common occurrence after partial nephrectomy and is a significant risk factor for chronic kidney disease. We aimed to create a model that predicts postoperative AKI in patients undergoing robot-assisted partial nephrectomy (RAPN).

METHODS

We identified 1,190 patients who underwent RAPN between 2008 and 2017 from a multicenter database. AKI was defined as a >25% reduction in eGFR from pre-RAPN to discharge. A nomogram was built based on a binary logistic regression that ultimately included age, sex, BMI, diabetes, baseline eGFR, and RENAL Nephrometry score. Internal validation was performed using the leave-one-out cross validation. Calibration was graphically investigated. The decision curve analysis was used to evaluate the net clinical benefit; a classification tree was used to identify risk categories. The same model was fit adding ischemia time during RAPN.

RESULTS

Median (IQR) age at surgery was 61 (50, 68) years; 505 (42%) patients were female, while 685 (58%) were male. Median (IQR) ischemia time during RAPN was 14 (10, 18) min. postoperative AKI occurred in 274 (23%) patients. All variables fitted in the model emerged as predictors of AKI (all P ≤ 0.005) and all were considered to build a nomogram. After internal validation, the area under the curve was 73%. The model demonstrated excellent calibration and improved clinical risk prediction at the decision curve analysis. In the low, intermediate, and high-risk groups the postoperative AKI rates were: 10%, 30%, and 48%, respectively. Adding ischemia time to the preoperative model fit the data better (likelihood ratio test: P < 0.001) and yielded an incremental area under the curve of 3% (95% confidence interval: 1, 5%) CONCLUSION: We developed a nomogram that accurately predicts AKI in patients undergoing RAPN. This model might serve (1) in the preoperative setting: for counsel patients according to their preoperative AKI risk (2) in the immediate postoperative: for identifying patients who would benefit from an early multidisciplinary evaluation, when considering also ischemia time.

Effect of Diabetes Mellitus on Acute Kidney Injury after Minimally Invasive Partial Nephrectomy: A Case-Matched Retrospective Analysis

Postoperative acute kidney injury (AKI) is still a concern in partial nephrectomy (PN), even with the development of minimally invasive technique. We aimed to compare AKI incidence between patients with and without diabetes mellitus (DM) and to determine the predictive factors for postoperative AKI. This case-matched retrospective study included 884 patients with preoperative creatinine levels ≤1.4 mg/dL who underwent laparoscopic or robot-assisted laparoscopic PN between December 2005 and May 2018. Propensity score matching was employed to match patients with and without DM in a 1:3 ratio (101 and 303 patients, respectively). Of 884 patients, 20.4% had postoperative AKI. After propensity score matching, the incidence of postoperative AKI in DM and non-DM patients was 30.7% and 14.9%, respectively (P < 0.001). In multivariate analysis, male sex and warm ischemia time (WIT) >25 min were significantly associated with postoperative AKI in patients with and without DM. In patients with DM, hemoglobin A1c (HbA1c) >7% was a predictive factor for AKI, odds ratio (OR) = 4.59 (95% CI, 1.47⁻14.36). In conclusion, DM increased the risk of AKI after minimally invasive PN; male sex, longer WIT, and elevated HbA1c were independent risk factors for AKI in patients with DM.

Joint consensus on anesthesia in urologic and gynecologic robotic surgery: specific issues in management from a task force of the SIAARTI, SIGO, and SIU

INTRODUCTION

Proper management of patients undergoing robotic-assisted urologic and gynecologic surgery must consider a series of peculiarities in the procedures for anesthesiology, critical care medicine, respiratory care, and pain management. Although the indications for robotic-assisted urogynecologic surgeries have increased in recent years, specific guidance documents are still lacking.

EVIDENCE ACQUISITION

A multidisciplinary group including anesthesiologists, gynecologists, urologists, and a clinical epidemiologist systematically reviewed the relevant literature and provided a set of recommendations and unmet needs on peculiar aspects of anesthesia in this field.

EVIDENCE SYNTHESIS

Nine core contents were identified, according to their requirements in urogynecologic robotic-assisted surgery: patient position, pneumoperitoneum and ventilation strategies, hemodynamic variations and fluid therapy, neuromuscular block, renal surgery and prevention of acute kidney injury, monitoring the Department of anesthesia, postoperative delirium and cognitive dysfunction, prevention of postoperative nausea and vomiting, and pain management in endometriosis.

CONCLUSIONS

This consensus document provides guidance for the management of urologic and gynecologic patients scheduled for robotic-assisted surgery. Moreover, the identified unmet needs highlight the requirement for further prospective randomized studies.

Outcome of kidney function after ischaemic and zero-ischaemic laparoscopic and open nephron-sparing surgery for renal cell cancer

Background

Nephron-sparing surgery (NSS) remains gold standard for the treatment of localised renal cell cancer (RCC), even in case of a normal contralateral kidney. Compared to radical nephrectomy, kidney failure and cardiovascular events are less frequent with NSS. However, the effects of different surgical approaches and of zero ischaemia on the postoperative reduction in renal function remain controversial.

We aimed to investigate the relative short- and long-term changes in estimated glomerular filtration rate (eGFR) after ischaemic or zero-ischaemic open (ONSS) and laparoscopic NSS (LNSS) for RCC, and to analyse prognostic factors for postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) stage ≥3.

Methods

Data of 444 patients (211 LNSS, 233 ONSS), including 57 zero-ischaemic cases, were retrospectively analysed. Multiple regression models were used to predict relative changes in renal function. Natural cubic splines were used to demonstrate the association between ischaemia time (IT) and relative changes in renal function.

Results

IT was identified as significant risk factor for short-term relative changes in eGFR (ß = − 0.27) and development of AKI (OR, 1.02), but no effect was found on long-term relative changes in eGFR. Natural cubic splines revealed that IT had a greater effect on patients with baseline eGFR categories ≥G3 concerning short-term decrease in renal function and development of AKI. Unlike LNSS, ONSS was significantly associated with short-term decrease in renal function (ß = − 13.48) and development of AKI (OR, 3.87). Tumour diameter was associated with long-term decrease in renal function (ß = − 1.76), whereas baseline eGFR was a prognostic factor for both short- (ß = − 0.20) and long-term (ß = − 0.29) relative changes in eGFR and the development of CKD stage ≥3 (OR, 0.89).

Conclusions

IT is a significant risk factor for AKI. The short-term effect of IT is not always linear, and the impact also depends on baseline eGFR. Unlike LNSS, ONSS is associated with the development of AKI. Our findings are helpful for surgical planning, and suggest either the application of a clampless NSS technique or at least the shortest possible IT to reduce the risk of short-time impairment of the renal function, which might prevent AKI, particularly regarding patients with baseline eGFR category ≥G3.

The association between intraoperative urine output and postoperative acute kidney injury differs between partial and radical nephrectomy

We sought to investigate the association between intraoperative urine output and postoperative acute kidney injury (AKI) in patients undergoing radical and partial nephrectomy. We retrospectively reviewed data of 742 patients. Postoperative AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. The relationship between intraoperative urine output and the risk of AKI was evaluated by multivariable logistic regression analysis in radical and partial nephrectomy, separately. Minimum P-value approach was used to find the optimal threshold of intraoperative oliguria associated with the risk of AKI. The incidence of AKI was 14.4% (67/466) after partial nephrectomy and 57.6% (159/276) after radical nephrectomy. For partial nephrectomy, multivariable analysis showed that renal ischemic time, operation time, open surgery and intraoperative transfusion were significantly associated with AKI. For radical nephrectomy, history of hypertension, baseline glomerular filtration rate and intraoperative mean urine output were significantly associated with AKI. Intraoperative mean urine output during radical nephrectomy was associated with AKI after radical nephrectomy, while not after partial nephrectomy. Mean urine output <1.0 mL/kg/h was determined to be an optimal cutoff of AKI after radical nephrectomy. Intraoperative oliguria may have different clinical implication for AKI between partial and radical nephrectomy.

Optimization of renal function preservation during robotic partial nephrectomy

Over the past few years, the role of robotic-assisted partial nephrectomy (RPN) has exponentially grown. Multiple recognized factors contribute to postoperative renal function in patients undergoing RPN. The aim of this review is to identify these potential factors, and to evaluate strategies that may help optimize the goal of renal function preservation. A nonsystematic literature review was performed to retrieve the most recent evidence on factors contributing to renal function post-RPN. Analyzed elements include baseline factors (tumor complexity and patient characteristics), intraoperative (surgical) factors (control of the renal hilum and type of ischemia, resection technique, renorrhaphy technique), and pharmacotherapeutics. In conclusion, the advantages of robotic surgery in the setting of partial nephrectomy (PN) are becoming well established. Maximal preservation of renal function remains a priority goal of the procedure, and it is influenced by a plethora of factors. Adequate patient selection using radiomics, control of comorbidities, utilization of evidence-based intraoperative techniques/strategies, and postoperative care are key components of postoperative preservation of renal function. Further investigations regarding these factors and their effects on long-term renal function are necessary and will continue to aid in guiding appropriate patient care.

Simple Postoperative AKI Risk (SPARK) Classification before Noncardiac Surgery: A Prediction Index Development Study with External Validation

BACKGROUND

Researchers have suggested models to predict the risk of postoperative AKI (PO-AKI), but an externally validated risk index that can be practically implemented before patients undergo noncardiac surgery is needed.

METHODS

We performed a retrospective observational study of patients without preexisting renal failure who underwent a noncardiac operation (≥1 hour) at two tertiary hospitals in Korea. We fitted a proportional odds model for an ordinal outcome consisting of three categories: critical AKI (defined as Kidney Disease Improving Global Outcomes AKI stage ≥2, post-AKI death, or dialysis within 90 days after surgery), low-stage AKI (defined as PO-AKI events not fulfilling the definition of critical AKI), and no PO-AKI.

RESULTS

The study included 51,041 patients in a discovery cohort and 39,764 patients in a validation cohort. The Simple Postoperative AKI Risk (SPARK) index included a summation of the integer scores of the following variables: age, sex, expected surgery duration, emergency operation, diabetes mellitus, use of renin-angiotensin-aldosterone inhibitors, baseline eGFR, dipstick albuminuria hypoalbuminemia, anemia, and hyponatremia. The model calibration plot showed tolerable distribution of observed and predicted probabilities in both cohorts. The discrimination power of the SPARK index was acceptable in both the discovery (c-statistic 0.80) and validation (c-statistic 0.72) cohorts. When four SPARK classes were defined on the basis of the sum of the risk scores, the SPARK index and classes fairly reflected the risks of PO-AKI and critical AKI.

CONCLUSIONS

Clinicians may consider implementing the SPARK index and classifications to stratify patients' PO-AKI risks before performing noncardiac surgery.

Acute kidney injury and intermediate-term renal function after clampless partial nephrectomy

OBJECTIVES

To evaluate the incidence and predictors of acute kidney injury after clampless partial nephrectomy, and its impact on intermediate-term renal function.

METHODS

The incidence and severity of acute kidney injury were assessed for 262 patients undergoing clampless partial nephrectomy between 2010 and 2015. The association between perioperative covariates and acute kidney injury was evaluated using multivariate logistic regression analysis. An annual change in estimated glomerular filtration rate from 1 year after surgery was calculated according to the presence or absence of acute kidney injury. An impact of acute kidney injury on postoperative renal impairment, defined as a ≥25% estimated glomerular filtration rate decrease, was evaluated.

RESULTS

Overall, 21 (8.0%) patients experienced grade 1 acute kidney injury after clampless partial nephrectomy, and grade ≥2 acute kidney injury was not observed. High tumor complexity was the only independent predictor of acute kidney injury. Estimated glomerular filtration rate in patients with acute kidney injury improved within 1 year, and annual estimated glomerular filtration rate changes were similar among patients with or without acute kidney injury. Ultimately, 13 (5.0%) patients showed postoperative renal impairment during the median follow-up period of 37 months. Advanced age and diabetes mellitus were independent risk factors for renal impairment, but acute kidney injury was not.

CONCLUSIONS

The incidence and severity of acute kidney injury after clampless partial nephrectomy are low. Low-grade acute kidney injury after clampless partial nephrectomy does not seem to affect intermediate-term renal function.

The effect of remote ischemic preconditioning on serum creatinine in patients undergoing partial nephrectomy: a study protocol for a randomized controlled trial

Background

Acute kidney injury (AKI) may develop during partial nephrectomy due to ischemic reperfusion injury induced by renal artery clamping or surgical insult. The effect of remote ischemic preconditioning (RIPC) on reducing the renal injury after partial nephrectomy has not been evaluated in terms of urinary biomarkers.

Methods/design

We will conduct a randomized controlled trial enrolling the patients who will undergo partial nephrectomy. In the study group, RIPC which consisted of four 5-min cycles of limb ischemia and reperfusion will be conducted after induction of anesthesia. Postoperative serum creatinine values, the incidence of AKI, and urinary biomarkers, including urinary creatinine, microalbumin, β-2 microglobulin, and N-acetyl-beta-D-glucosaminidase, will be compared between groups during the postoperative 2 weeks. Regional oxygen saturation on the skin of the contralateral kidney will be measured to evaluate the association between intraoperative regional oxygen saturation values and renal injury of the operating side.

Discussion

We expect that our trial may demonstrate the effect of RIPC on mitigating the immediate postoperative renal injury and improving patient outcomes after partial nephrectomy. Moreover, our patients will undergo ^99mTc-DTPA radionuclide scintigraphy to calculate glomerular filtration rate 6 and 12 months after surgery. This data should show the long-term effect of RIPC.

Trial registration

ClinicalTrials.gov, ID: NCT03273751. Registered on 6 September 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2820-3) contains supplementary material, which is available to authorized users.

Association between postoperative hyponatremia and renal prognosis in major urologic surgery

Recent evidence for the clinical significance of postoperative hyponatremia after urologic surgeries remains scarce. We examined the incidence, risk factors, and outcomes of electrolyte imbalance in urologic surgery. Patients with newly developed hyponatremia, defined as a sodium level lower than 135 mEq/L within 7 days after surgery, were included in our study group. The primary outcome was progression to end-stage renal disease (ESRD). Secondary outcome was composition of progression to ESRD and creatinine doubling/eGFR halving from baseline. A survival analysis with a multivariable Cox proportional hazard model was performed. We included 9,206 cases of bladder, prostate, ureter, and kidney surgery. Incidence of new-onset postoperative hyponatremia was 15.4% (1,414/9,206). Postoperative hyponatremia mostly developed in patients with high-risk perioperative characteristics. The development of postoperative hyponatremia was independently associated with progression to ESRD (adjusted HR 1.343, 95% CI 1.082-1.680, P = 0.007). The secondary outcome was also related to the electrolyte imbalance in prostate (adjusted HR 1.729, 95% CI 1.145-2.612, P = 0.009) and kidney (adjusted HR 1.339, 95% CI 1.099-1.632, P = 0.004) surgery. Postoperative hyponatremia in urologic surgery was a common electrolyte imbalance in patients with high-risk perioperative status, and associated with worse renal prognosis.

Systemic Lupus Erythematosus Is Associated With Increased Adverse Postoperative Renal Outcomes and Mortality: A Historical Cohort Study Using Administrative Health Data

BACKGROUND

Systemic lupus erythematosus (SLE) is a common autoimmune connective tissue disease that mainly harms kidneys, heart, lungs, and nervous system. Effects of surgical stimulus and anesthesia combined with SLE-related pathologies may increase morbidity and mortality. Therefore, we aimed to evaluate the association between SLE (versus none) and postoperative renal, cardiac, and in-hospital mortality complications among patients undergoing major surgeries.

METHODS

We obtained censuses of 2009 to 2011 inpatient hospital discharges across 7 states and conducted a retrospective cohort study by using International Classification of Diseases and Injuries, Version 9, diagnosis codes, procedure codes, and present-on-admission indicators. We included patients who had major surgery and matched each SLE discharge up to 4 control discharges for potential confounders. We assessed the association between matched SLE patients and controls on in-hospital renal complications, cardiovascular complications, and in-hospital mortality using separate logistic regression models.

RESULTS

Among 8 million qualifying discharges, our sample contained 28,269 SLE patients matched with 13,269 controls. SLE was associated with a significantly higher risk of postoperative renal complications, with an estimated odds ratio (99% CI) of 1.33 (1.21, 1.46); P < .001. In addition, SLE was significantly associated with a higher risk of in-hospital mortality, with an estimated odds ratio (99% CI) of 1.27 (1.11, 1.47); P < .001. However, we found no significant association between SLE and cardiac complications, with an estimated odds ratio (99% CI) of 0.98 (0.83, 1.16), P = .79.

CONCLUSIONS

This is, by far, the largest clinical study for postoperative outcomes of SLE patients with adequately powered statistical analyses. We concluded that SLE was associated with a higher risk of renal complications and in-hospital mortality but not cardiac events after major surgery. In SLE patients, more aggressive measures should be taken to prevent renal injury in the perioperative period.

Effect of ulinastatin on postoperative renal function in patients undergoing robot-assisted laparoscopic partial nephrectomy: a randomized trial

BACKGROUND

Robot-assisted laparoscopic partial nephrectomy (RLPN) is an emerging technique for treating small renal masses. Although RLPN has many advantages, ischemic kidney injury is inevitable during renal artery clamping. The overall incidence of acute kidney injury (AKI) after partial nephrectomy has been reported to be up to 39%. Moreover, effective pharmacological protection against AKI after partial nephrectomy has not yet been demonstrated. Ulinastatin has been shown to protect the kidney from ischemia/reperfusion injury via its anti-inflammatory and anti-oxidant activities. Therefore, this study aimed to evaluate the effect of ulinastatin on postoperative kidney function in patients undergoing RLPN.

METHODS

In this randomized, double-blinded, placebo-controlled study, patients undergoing RLPN received either intravenous ulinastatin (100,000 units/10 kg; ulinastatin group, n = 35) or the same volume of normal saline (control group, n = 35) for 1 h starting 10 min before renal artery clamping. The primary outcome was incidence of postoperative AKI. Secondary outcomes were levels of serum creatinine, estimated glomerular filtration rate (eGFR), cystatin C, and inflammatory markers and were measured before operation and at 1, 24, 48, and 72 h postoperatively.

RESULTS

The incidence of postoperative AKI was 18% in the ulinastatin group, whereas it was 30% in the control group (p = 0.251). No significant differences in postoperative changes of serum creatinine, eGFR, or cystatin C were observed between the two groups. Postoperative inflammatory markers including C-reactive protein, white blood cell count, and neutrophil percentage were significantly increased until 72 h after operation compared to the preoperative values in both groups, with no significant differences between the groups.

CONCLUSIONS

Administration of ulinastatin (100,000 units/10 kg) during the warm ischemia and reperfusion periods did not show any beneficial effects on postoperative kidney function or inflammatory responses in patients undergoing RLPN.

Risk factors for acute renal failure in nephrectomized patients treated in a university hospital

Background

New surgical techniques for nephrectomy mainly related to early diagnosis made possible by advances in imaging studies have been developed in recent decades. However, postoperative renal dysfunction is a constant concern because of the major problems faced by healthcare services and by the patients themselves. To assess risk factors for developing acute renal failure (ARF) in patients submitted to nephrectomy in a university hospital.

Methods

Seventy-seven patients submitted to nephrectomy for benign and malignant diseases in a university hospital were evaluated in respect to preoperative and postoperative creatinine clearance. Demographic (gender, age), clinical (cancer, diabetes, high blood pressure, chronic kidney disease) and surgical (anesthesia time, open or laparoscopic surgery) variables were also analyzed.

Results

Of the 77 patients, 72 met the inclusion criteria. Of these, ten (13.8%) had a diagnosis of chronic renal failure (CRF), 30 (48%) had stage I ARF and one (16.1%) had stage II ARF. The anesthesia time, type of surgery (open or laparoscopy), total or partial nephrectomy, the side of the procedure, hypertension, diabetes, CRF, renal cancer, preoperative and postoperative creatinine concentrations were analyzed. Only the difference between preoperative and postoperative creatinine clearance was clinically significant (P<0.001).

Conclusions

An altered preoperative renal function is a risk factor for the development of ARF in nephrectomized patients.

Dipeptidyl peptidase 4 inhibitor use is associated with a lower risk of incident acute kidney injury in patients with diabetes

Objectives

Dipeptidyl peptidase 4 inhibitor (DPP4i) use potentially slows the progression of diabetic kidney disease, but its effects on the risk of acute kidney injury (AKI) are unclear. We aimed to assess the association between DPP4i use and incident AKI episodes from a nationally representative cohort in Taiwan.

Materials and Methods

All patients newly diagnosed with diabetes mellitus (DM) between 2008, when DPP4i use was first approved in Taiwan, and mid-2013 were enrolled. Propensity score-matched diabetic DPP4i users, who received DPP4i for at least 90 days, and nonusers were selected. The primary and secondary outcomes were incident AKI and dialysis-requiring AKI during follow-up. Cox proportional hazard analyses were performed to examine the effect of DPP4i on the risk of AKI.

Results

We enrolled 923,936 diabetic patients; of these, 83,638 DPP4i users (75.7% sitagliptin, 14.6% vildagliptin, and 9.7% saxagliptin) were propensity score-matched to 83,638 non-users. After an average 3.6-year follow-up, 1.56% and 0.35% of DPP4i users and 2.53% and 0.56% of non-users developed incident AKI and dialysis-requiring AKI, respectively. DPP4i use was significantly associated with lower risk of incident AKI (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.53–0.61) and risk of dialysis-requiring AKI (HR 0.57, 95% CI 0.49–0.66). The risk reduction was consistent regardless of DPP4i type, the presence of chronic kidney disease, the previous acute kidney injury, and age.

Conclusions

DPP4i use is associated with reduced risk of mild and severe forms of AKI among patients with incident DM. DPP4i may be an important class of anti-glycaemic agent with reno-protective effects.

Baseline Chronic Kidney Disease and Ischemic Method of Partial Nephrectomy Are Important Factors for the Short- and Long-Term Deterioration in Renal Function for Renal Cell Carcinoma Staged T1-T2: A Retrospective Single Center Study

The renal functions of 215 patients (24 with benign renal mass, the rest with RCC staged T1-T2) who underwent partial nephrectomy (PN) between 2003 and 2014 were evaluated to identify predictors of short- and long-term deterioration in renal function after PN among renal cell carcinoma (RCC) patients with or without preoperative predisposition to chronic kidney disease (CKD) and among patients with benign renal mass. The 1- and 5-year predictive factors for de novo CKD were statistically analyzed. The incidence of de novo CKD differed significantly (p < 0.001) among patients with benign renal mass, those with RCC but no preoperative CKD predisposition, and those with RCC combined with preoperative CKD predisposition. Independent predictors for de novo CKD at 1 year postoperatively included intraoperative ischemic method, ECOG score, elevated albumin levels, male sex, and smoking exposure (in pack-years). Predictors for de novo CKD at 5 years postoperatively included hypertension, high preoperative albumin levels, De Ritis ratio (aspartate aminotransferase/alanine aminotransferase ratio), smoking exposure, and preoperative predisposition to CKD. Preoperative predisposition to CKD and ischemic method applied during PN, along with other preoperative parameters, were important factors affecting postoperative renal function deterioration in patients with T1-T2 RCC.