Preoperative Kidney Research Articles

Preoperative Risk, Blood Pressure, and Acute Kidney Injury.

Preoperative Risk, Blood Pressure, and Acute Kidney Injury.

Progression in the severity of aortic stenosis according to race among those with advanced chronic kidney disease.

There is a higher prevalence of aortic stenosis (AS) in patients with advanced chronic kidney disease (CKD) and European ancestry. However, studies comparing AS progression in white and black patients in an advanced CKD population do not exist. Advanced CKD (stage IV-V) patients who were referred to the UNC Cardiorenal Clinic for pre-operative kidney transplant evaluation, and diagnosed with either AS (mild, moderate, or severe) or a left ventricular outflow tract velocity ≥2 m/s at any point between 2006-2016 were eligible for inclusion. Serial transthoracic echocardiograms over the 10-year period determined AS progression. All echocardiograms acquired after renal transplantation or aortic valve replacement were excluded. The rates of change of three indices of AS severity [mean gradient, aortic valve area (AVA), and aortic valve velocity] were compared between white and black patients. Mixed effects linear models with repeated measures were used to estimate the overall and race-stratified yearly rate of progression for each index, adjusted for age, sex, smoking status, dialysis, and baseline cholesterol. Of 1,283 patients, 140 (34% white, 66% black) developed or had baseline AS. Initially, 81% had no AS, 13% had mild, and 6% had moderate. White patients were more likely to be male and less likely to be on hemodialysis compared to black patients. No differences in AS severity (P=0.55) or age (60 vs. 58 years, P=0.34) were seen at baseline. In white vs. black patients, mean gradient increased at 1.90 (95% CI: 0.79, 3.01) mmHg/year vs. 1.46 (95% CI, 0.79, 2.14) mmHg/year, P=0.20, AVA decreased at -0.10 (95% CI: -0.15, -0.05) m2/year vs. -0.08 (95% CI: -0.11, -0.05) m2/year, P=0.13, and transvalvular velocity increased at 0.11 (95% CI: 0.04, 0.18) m/s/year vs. 0.07 (95% CI: 0.03, 0.11) m/s/year, P=0.09. Compared to black patients, white patients in an advanced CKD cohort may have exhibited more rapid progression of AS. Ours is the first study to analyze racial differences in such a population. A study with a larger sample size is needed to confirm our findings.

The Relationship Between Preoperative Kidney Function and Weight Loss After Bariatric Surgery in Patients with Estimated Glomerular Filtration Rate ≥ 30mL/min: Tehran Obesity Treatment Study.

Severe obesity can lead to progressive kidney injury and chronic kidney disease (CKD). The current study aimed at determining whether preoperative kidney function level in patients with estimated glomerular filtration rate (eGFR) ≥30mL/min affects weight loss after bariatric surgery. A total of 1958 bariatric patients underwent laparoscopic sleeve gastrectomy and gastric bypass from March 2013 to March 2017. The patients were categorized according to preoperative eGFR (30-59, 60-89, 90-124, and ≥ 125mL/min). Changes in body mass index (BMI), percentage of total weight loss (TWL%), and percentage of excess weight loss (EWL%) were compared across the eGFR categories. Moreover, multivariable logistic regression analysis was used to evaluate the relationship between eGFR and insufficient weight loss (defined as not achieving 50% EWL at 12months after surgery). Preoperative eGFR was positively associated with unadjusted ΔBMI (P trend < 0.001), TWL% (P trend < 0.001), and EWL% (P trend = 0.007) after 12months of surgery. However, these associations were no longer significant after multivariable adjustment. Further, univariate analysis demonstrated a positive relationship between preoperative eGFR and insufficient weight loss (odds ratio [OR] 1.38; 95% confidence interval [CI] 1.11-1.71; P = 0.004). By contrast, preoperative eGFR was not a predictor of insufficient weight loss in multivariable logistic regression analysis (OR 0.98; 95% CI 0.46-1.24; P = 0.886). Although patients with lower preoperative eGFR experience less weight loss after bariatric surgery, preoperative kidney function does not appear to have an independent impact on postoperative weight loss in patients with eGFR ≥30mL/min.

The risk of renal function deterioration in abdominal aortic stent graft patients with and without previous kidney function failure – an analysis of risk factors

PurposeKidney failure influences the treatment outcomes of abdominal aortic aneurysm (AAA). A prospective study of renal function before and after aortic stent-graft treatment was performed. Special attention was paid to the influence of preoperative kidney function as well as the impact of the radiological follow-up.Material and methodsA total of 214 endovascularly treated AAA patients were included. In all cases, pre- and postope-rative estimated glomerular filtration rate (eGFR) and serum creatinine were noted. Patients were prospectively followed up for a minimum of two years.ResultsThe baseline eGFR was 69.38 ± 16.29 ml/min/1.73 m2. Chronic kidney disease at baseline was noted in 29% of patients. In the direct postoperative period, acute kidney injury was identified in 8.4% of cases. Additional endo-vascular procedures within two years of observation were performed in 5.6% of cases, and over the two years of follow-up, in the study group from one to six angio-computed tomographic scans (angio-CT) per patient were performed. The mean eGFR value after the 24-month follow-up was significantly lower than the preoperative value. Among the factors influencing kidney function, an angio-CT during the same hospital stay of the primary stent-graft procedures was identified. The type of stent-graft, contrast volume during the primary procedure, need for reintervention, concomitant disease presence, and statin use did not show statistical significance.ConclusionsAngio-CT followed by stent-graft implantation over a short time interval (within the same hospitalisation) significantly worsened renal function in the late follow-up and should be avoided in elective AAA cases.

Association of Serum Zinc Concentration with Preservation of Renal Function After Bariatric Surgery: a Retrospective Pilot Study.

Although serum zinc level (Zn) is known to impact renal function in patients with diabetes, their correlation following bariatric surgery remains unknown. This study aimed at assessing the association of Zn with estimated glomerular filtration rate (eGFR) after laparoscopic sleeve gastrectomy (LSG). One hundred and twenty-nine patients in total (mean age, 38.1 ± 10.8; body mass index, 39.1 ± 5.1 kg/m2) with normal preoperative kidney function undergoing LSG at a single tertiary referral center were reviewed. The primary study endpoint was the relationship between Zn and post-LSG eGFR at 12-month follow-up. The secondary outcomes were the associations of percentage weight loss (%WL) with changes in Zn (△Zn) and eGFR (△eGFR). The incidence of zinc deficiency was 8.5%, 8.1%, and 29.9% at baseline, post-LSG and one- and 12-month follow-up, respectively. At 12-month follow-up, Zn dropped from 104.1 ± 19.2 to 85.3 ± 38.9 μg/dL (p = 0.001), while eGFR levels decreased from 106.6 ± 10.3 to 102.1 ± 19.4 mL/min per 1.73 m2 (p = 0.025). Zn correlated positively with eGFR at 6-month (r = 0.252, p = 0.037) and 12-month (r = 0.41, p = 0.001) follow-ups. Multiple linear regression analyses including baseline variables of age, sex, BMI, %WL, and diabetes identified Zn and %WL as independent predictors of eGFR at 12-month follow-up. There was no evidence of multicollinearity among these variables. Despite positive association between %WL and △eGFR (r = 0.222, p = 0.031), no correlation was noted between %WL and △Zn (r = - 0.129, p = 0.40). The results demonstrated a positive relationship between post-LSG serum zinc levels and preservation of renal function among patients with obesity in a surgical setting. Large-scale studies are warranted to support the findings.

Neutrophil Gelatinase-associated Lipocalin as a Marker of Postoperative Acute Kidney Injury Following Cardiac Surgery in Patients with Preoperative Kidney Impairment.

Acute kidney injury (AKI) is a serious complication of cardiac surgery. The current 'gold standard' for determining AKI is change in serum creatinine and urine output, however, this change occurs relatively late after the actual injury occurs. Identification of new biomarkers that detect early AKI is required. Recently, new biomarkers, such as the NephroCheck® Test and AKIRisk have also been tested and found to be good indicators of AKI. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in paediatric patients but has displayed varied results in adult populations, particularly post cardiac surgery. The aim of this study was to assess the value of urinary NGAL as a biomarker of AKI in patients with pre-existing renal impairment (eGFR >15ml/min to eGFR<60ml/min). A post-hoc analysis of urinary NGAL concentrations from 125 patients with pre-existing kidney impairment, who participated in a randomised trial of haemofiltration during cardiac surgery, was undertaken. Urinary NGAL was measured using ELISA at baseline, post-operatively and 24 and 48 hours after surgery, and serum creatinine was measured pre and postoperatively and then at 24, 48, 72 and 96 hours as routine patient care. NGAL concentrations were compared in patients with and without AKI determined by changes in serum creatinine concentrations. A Kaplan-Meier plot compared survival for patients with or without AKI and a Cox proportional hazards analysis was performed to identify factors with the greatest influence on survival. Following surgery, 43% of patients developed AKI (based on KDIGO definition). Baseline urinary NGAL was not found to be significantly different between patients that did and did not develop AKI. Urinary NGAL concentration was increased in all patients following surgery, regardless of whether they developed AKI and was also significant between groups at 24 (p=0.003) and 48 hours (p<0.0001). Urinary NGAL concentrations at 48 hours correlated with serum creatinine concentrations at 48 hours (r=0.477, p<0.0001), 72 hours (r=0.488, p<0.0001) and 96 hours (r=0.463, p<0.0001). Urinary NGAL at 48 hours after surgery strongly predicted AKI (AUC=0.76; P=0.0001). A Kaplan- Meier plot showed that patients with postoperative AKI had a significantly lower 7-year survival compared with those without AKI. Postoperative urinary NGAL at 48 hours >156ng/mL also strongly predicted 7-year survival. However, additive EuroSCORE, age, current smoking and post-operative antibiotics usage were distinctly significantly more predictive of 7-year survival as compared with postoperative urinary NGAL at 48 hours >156ng/mL. Our study demonstrated that postoperative urinary NGAL levels at 48 hours postsurgery strongly predicts the onset or severity of postoperative AKI based on KDIGO classification in patients with preoperative kidney impairment and were also strongly related to 7-year survival.

Prevention of kidney injury after myocardial ischemia reperfusion is achievable with short-term protein restriction

Introduction: Kidney injury is a serious complication after cardiovascular surgery. Left ventricular dysfunction, pre-operative kidney dysfunction and inflammation can predict kidney injury after myocardial reperfusion. Objectives: We aimed to study whether short-term protein restriction (PR) would influence blood urea nitrogen (BUN) levels after myocardial reperfusion injury. Materials and Methods: Male Wistar rats fed with either AIN-93M or AIN-93M protein restricted diet one week before myocardial reperfusion injury. After surgery, feeding continued with AIN-93M for 1 week. Results: BUN levels increased significantly compared to the pre-operative level in the control group (P=0.03) and decreased significantly in the protein-restricted group (P=0.01). Multivariate analysis showed that PR through its effect on blood glucose (β=1.2, 95% CI=0.1- 2.34), IL-6 (β=-2.22, 95% CI=-3.9–-0.54) and left ventricular ejection fraction (LVEF) (β=-1.21, 95% CI=-2.34- 0.09) was able to protect the kidney from myocardial reperfusion. Conclusion: Short-term PR through modulating pre-operative IL-6, post-operative blood glucose levels and LVEF could prevent kidney injury after myocardial reperfusion injury.

Effect of sevoflurane-based or propofol-based anaesthesia on the incidence of postoperative acute kidney injury: A retrospective propensity score-matched analysis.

Propofol may help to protect against ischaemic acute kidney injury (AKI); however, research on this topic is sparse. The current study aimed to investigate whether there were differences in the incidence of postoperative AKI after lung resection surgery between patients who received propofol-based total intravenous anaesthesia (TIVA) and those who received sevoflurane-based inhalational anaesthesia. A retrospective observational study. A single tertiary care hospital. Medical records of patients aged 19 years or older who underwent curative lung resection surgery for nonsmall cell lung cancer between January 2005 and February 2018 were examined. After propensity score matching, the incidence of AKI in the first 3 postoperative days was compared between patients who received propofol and those who received sevoflurane. Logistic regression analyses were also used to investigate whether propofol-based TIVA lowered the risk of postoperative AKI. The analysis included 2872 patients (1477 in the sevoflurane group and 1395 in the propofol group). After propensity score matching, 661 patients were included in each group; 24 (3.6%) of the 661 patients in the sevoflurane group developed AKI compared with 23 (3.5%) of the 661 patients in the propofol group (95% confidence intervals of difference in incidence -0.019 to 0.022, P = 0.882). The logistic regression analyses revealed that the incidence of AKI was not different in the two groups (odds ratio 0.96, 95% confidence interval 0.53 to 1.71, P = 0.882). In this retrospective study, no significant difference was found in the incidence of postoperative AKI after lung resection surgery between patients who received propofol-based TIVA and those who received sevoflurane-based inhalational anaesthesia. Considering the methodological limitation of this retrospective study, further studies are required to confirm these results.

COMPARATIVE STUDY BETWEEN THE EFFECTIVENESS OF NACETYLCYSTEINE AND BICARBONATE IN RENAL PROTECTION AFTER CARDIAC BYPASS SURGERY

Background: Cardiac surgery-associated acute kidney injury is a common and serious postoperative complication of cardiac surgery that employs cardiopulmonary bypass. Acute renal failure occurs in up to 30% of patients who undergo cardiac surgery. Aim of the Work: to compare between the effectiveness of acetylcysteine and bicarbonate in prevention of acute kidney injury in patients undergoing elective cardiac bypass surgeries. Patients and Methods: This interventional prospective comparative randomized single blinded study was conducted on 120 cardiac patients, hypertensive, diabetic with normal preoperative kidney functions, of either sex, aging >40 years old, scheduled for elective cardiac bypass surgery at Cardiothoracic Surgery Department of Ain Shams University hospitals. Study started June 2017 and ended December 2018; after the approval of the ethical medical committee and obtaining a written informed consent from thepatient. Results: The current study showed nonsignificant correlation between usage of NAC and bicarbonate and renal protection after cardiac bypass surgeries. Also the current study showed the more the time of aortic clamping, time of CPB and the lower the MAP during CPB, the more the rise in serum creatinine after 24 hours. Conclusion: The current study shows that perioperative intravenous administration of NAC with or without sodium bicarbonate may not have a role in prevention of acute kidney injury in patients undergoing elective cardiac bypass surgeries as detected by serum creatinine and creatinine clearance.

Reliability of computed tomography-based renal cortex volume to determine split renal function in preoperative living kidney donors.

Objective:The purpose of this study was to assess the utility of CT-based renal cortex volume to estimate split renal function (SRF) in pre-transplant living kidney donors and to evaluate its reliability to predict graft function in the recipients.Methods:Our study recruited all adult potential donors who had both Tc-99m-diethylenetriamine pentacetate (DTPA) scintigraphy and CT angiography of the abdominal aorta done before donating their kidney. We compared the correlation between CT-based renal cortex volume combined with kidney function and DTPA scan as well as post-donation kidney function in the recipients.Results:The correlation between CT-based split cortex volume and DTPA-measured SRF before transplantation was strong (intraclass correlation coefficient = 0.954–0.968). The inter-rater reliability of two radiologists also showed substantial agreement (intraclass correlation coefficient = 0.97, p < 0.001). In contrast, the correlations between renal cortical volume of donated kidney adjusted to recipient body weight and recipient kidney function was poor at both 2 week and 2 year follow-up.Conclusion:CT-based renal cortex volume combined with pre-operative kidney function appears to be precise and reproducible to evaluate pre-transplant SRF. Nevertheless, the prediction of recipient graft function needs to be further investigated to ensure a good outcome.Advances in knowledge:This method is practicable for all potential donors who undergo kidney transplantation in terms of streamline donor workup without compromising information.

A minimally invasive alternative for the treatment of nutcracker syndrome using individualized three-dimensional printed extravascular titanium stents.

BackgroundThis study was designed to evaluate the clinical and radiographic outcomes of patients with nutcracker syndrome (NCS) who were treated with three-dimensional printing (3DP) extravascular titanium stents (EVTSs). The 3DP EVTS was expected to release the hypertension of the left renal vein (LRV) produced by its compression between the superior mesenteric artery (SMA) and the aorta without causing any complications.MethodThe pre-operative kidney model of each patient was printed out to enable surgical planning. After that, the EVTS was designed based on the LRV's primitive physiologic structure using computer-aided design software, and each stent was printed out with a precision setting of 20 μm. Seventeen patients who had been suffering from NCS underwent laparoscopic 3DP EVTS placement. The surgical procedure was designed for the placement of EVTS, taking great care in positioning and fixing the stent. Surgical data, which included patient demographic characteristics as well as pre- and post-operative test results, were collected and analyzed.ResultsThe mean duration of surgery was 75 ± 9 min, and the mean blood loss was 20 ± 5 mL. Computed tomography examinations revealed that the pre- and post-operative angle between the SMA and the aorta ranged from 18.7° ± 4.3° to 48.0° ± 8.8° (P < 0.05); in patients with left varicocele, the mean diameter of the left spermatic vein ranged from 3.7 ± 0.5 to 1.3 ± 0.2 mm (P < 0.05). Moreover, Doppler ultrasound examinations showed that the peak velocity of blood flow at the hilar area ranged from 12.4 ± 3.3 to 18.5 ± 3.4 cm/s (P < 0.05). No side effects were observed in the 24 to 42 months following surgery.ConclusionThe findings after 2 years of follow-up suggest that the 3DP EVTS is a safe and effective minimally invasive alternative for the treatment of NCS.

Chronic Kidney Disease After Liver Transplantation: Impact of Extended Criteria Grafts.

The use of extended criteria donor (ECD) grafts has been associated with acute kidney injury (AKI) after liver transplantation. However, the relation between graft quality and development of chronic kidney disease (CKD) remains unknown. Therefore, the aim of this study was to analyze the impact of ECD grafts for CKD after liver transplantation. All patients (2007-2015) transplanted for end-stage liver disease at our center were assessed. Longterm kidney function was divided into 4 groups: no CKD (estimated glomerular filtration rate [eGFR], ≥60 mL/minute/1.73 m2 ), mild CKD (eGFR, 30-59 mL/minute/1.73 m2 ), severe CKD (eGFR, 15-29 mL/minute/1.73 m2 ), and end-stage renal disease (ESRD). Marginal donation after brain death (DBD) grafts (donor age, >70 years; body mass index, >35 kg/m2 ; cold storage, >12 hours) and donation after circulatory death (DCD) grafts were considered ECD grafts. Overall, 926 patients were included, and 43% received an ECD graft (15% marginal DBD; 28% DCD). After 5 years, 35% developed CKD; severe CKD and ESRD occurred in only 2% and 1%, respectively. CKD rates were comparable for all 3 graft groups (standard group, 36%; marginal DBD group, 29%; DCD group, 35%; standard versus marginal DBD groups, P=0.16; standard versus DCD group, P=0.80). None of the ECD criteria were identified as independent risk factors in a Cox regression model for CKD. Risk factors included recipient age, female sex, and preoperative kidney function. Furthermore, recipients who had severe acute kidney injury (AKI; Kidney Disease: Improving Global Outcomes stages 2 and 3) had a 1.8-fold increased risk for CKD. Longterm kidney function of recipients with severe AKI depended on the recovery of kidney function in the first postoperative week. In conclusion, there is no direct relation between the use of ECD grafts and CKD after liver transplantation. However, caution should be taken in recipients who experience severe AKI, regardless of graft type.

Coronary artery bypass grafting in patients with low ejection fraction: what are the risk factors?

Left ventricular (LV) dysfunction alone is insufficient as an independent predictor of postoperative complications and mortality in coronary artery bypass graft (CABG) surgery. Our objective was to identify additional independent risk factors in patients with low left ventricle ejection fraction (EF) who underwent CABG. We retrospectively analyzed CABG results of 346 consecutive patients with low EF (≤30%) in a single institution between 2009 and 2015. The primary study endpoint was 30-day all-cause mortality. The secondary endpoints were the development of major adverse cardiac events (MACE) and renal complications after operation. A subgroup of patients underwent additional analyses of the interaction between extents of viable myocardium and postoperative endpoints. The analysis showed that preoperative hemodynamic instability (AOR=4.57; 95% CI: 1.53-13.7, P=0.007) and serum creatinine >166 µmol/L (AOR=3.46; 95% CI: 1.12-10.7, P=0.031) were independent predictors of 30-day death. Both urgent and emergency operations were predictors for MACE (P=0.038; P=0.005) and renal complications (P=0.004; P=0.007). Pre-existing diabetes mellitus increased the likelihood of renal complications (P=0.020). In the sub-analysis of patients with viable myocardium, the mortality was significantly lower with predicted mortality (P=0.014). Patients with significant LV dysfunction undergoing isolated CABG have fair short-term survival even with EF less than 30%. Hemodynamic instability prior to operation and preoperative kidney dysfunction are strong predictors of mortality in patients with low EF. Favorable coronary targets, meticulous operative techniques, and optimal surgical timing before hemodynamic deterioration occurs are essential to minimize the risk of revascularization complications and early postoperative mortality.

Chronic kidney disease and acute kidney injury in arthroplasty patients over 65 years of age.

The purpose of this study was to evaluate the prevalence of chronic kidney disease (CKD) and the incidence of perioperative acute kidney injury (AKI) in primary arthroplasty patients over 65years of age. Risk factors, perioperative events and the outcome of surgery were evaluated. This retrospective, hospital register-based study consists of patients operated in 2014 in the area of Oulu, Finland. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula. The incidence of AKI was evaluated based on the serum creatinine criteria of the KDIGO (Kidney Disease, Improving Global Outcomes) classification. Of the 807 patients, 60.8% had mildly decreased (60-89ml/min/1.73m2 ) and 13.5% moderately to severely decreased eGFR (<60ml/min/1.73m2 ) preoperatively. Only 33.9% of patients with an eGFR<60ml/min/1.73m2 had a diagnosis of a kidney disease. In emergencies, 46.9% of patients with an eGFR<60ml/min/1.73m2 were deceased at the 12-month follow-up point. The measurement of postoperative sCr was not complete (477/807) and was allocated to emergencies and older patient with more comorbidities. Of those whose postoperative sCr was available, 14 (2.9%) fulfilled AKI criteria. Most of the AKI cases had a decrease in eGFR preoperatively, a diagnosed kidney disease or diabetes mellitus. Impairment of kidney function was common and was related to mortality in emergency arthroplasties. Measurements of postoperative sCr were allocated to high risk patients. Preoperative kidney function, kidney disease and diabetes mellitus were important determinants for perioperative AKI.

Analgesia after major laparoscopic surgery in patients with chronic kidney disease: A retrospective cohort study

The amount of reduction in opioid doses and its effect on postoperative pain outcomes in chronic kidney disease (CKD) patients in the perioperative setting remains unclear. This study aimed to investigate differences in postoperative pain outcomes after major laparoscopic surgery between patients with CKD and those with normal preoperative kidney function. Medical records of patients who underwent laparoscopic major abdominal surgery from January 2010 to December 2016 were retrospectively reviewed, and 6,612 patients were finally included. During postoperative day (POD) 0–3, patients with an estimated glomerular filtration rate (eGFR) < 30 mL min−1 1.73 m−2 had 3.5% lower morphine equivalent consumption than those with an eGFR ≥ 90 mL min−1 1.73 m−2 (P = 0.023), whereas patients with preoperative eGFR between 60–90 mL min−1 1.73 m−2 and 30–60 mL min−1 1.73 m−2 showed no significant differences in morphine equivalent consumption. Additionally, pain scores at rest during POD 0–3 were not significantly associated with preoperative kidney function. In conclusion, our results suggest that patients with mild to moderate CKD (stage 2–3) did not require reduction of opioid analgesics during POD 0–3, compared to patients with normal preoperative kidney function. Only patients with severe CKD (stage ≥ 4) might require a slight reduction of opioid analgesics.

The impact of kidney function on colorectal cancer patients with localized and regional diseases: An observational study from Taiwan

Impaired kidney function is associated with different diseases. However, its impact on colorectal cancer has not been clarified. In order to understand the effect of preoperative kidney function on the outcome of patients with cancer, we analyzed colorectal cancer patients with localized or regional diseases. In total, 3731 stage I to III colorectal cancer (CRC) patients were analyzed in Chang Gung Memorial Hospital. Modification of Diet in Renal Disease (MDRD) formula was used for estimated glomerular filtration rate (eGFR). Receiver operating characteristic (ROC) analysis for kidney function cut-off value; Chi-square method, independent t test, or analysis of variance (ANOVA) method for clinicopathological factors; Kaplan-Meier method for disease-free survival (DFS); Cox proportional hazard model for multivariate analysis. Among colon cancer patients, low eGFR (MDRD <70) was associated with more male patients, T2 stage, patients without adjuvant chemotherapy, and patients with elevated creatinine level. Low eGFR is a significant risk factor only for stage III colon cancer (hazard ratio 1.70, 95% CI: 1.28-2.26; P < 0.001). Furthermore, postoperative adjuvant chemotherapy did not significantly increase 5-year DFS for both high and low eGFR groups in stage II patients (5 yrs DFS, 94.8% vs. 84.1%, P = 0.098 for high eGFR subgroup; and 75.0% vs. 75.8%, P = 0.379 for low eGFR subgroup). However, significant improvement of 5-yrs DFS after chemotherapy was found in low eGFR stage III colon cancer patients (64.7% vs. 39.4%, P < 0.001 for low eGFR subgroup). In contrast, no significant DFS difference was caused by chemotherapy for high eGFR stage III subgroup (70.5% vs. 63.9%, P = 0.110). Although low eGFR is an independent risk factor for stage III colon cancer. However, the adjuvant chemotherapy impacts on stage III colon cancer patients differently according to eGFR status.

Chronic kidney cortical damage is associated with baseline kidney function and albuminuria in patients managed with radical nephrectomy for kidney tumours

This study evaluated the relationship between histological markers of chronic kidney damage in patients undergoing radical nephrectomy for kidney tumours and preoperative kidney function, degree of albuminuria, and changes in glomerular volume. A schema to grade chronic kidney damage could be used to identify patients at risk of developing CKD following nephrectomy. Non-neoplastic cortical tissue was sourced from 150 patients undergoing radical nephrectomy for suspected kidney cancer. This tissue was evaluated for indicators of chronic damage, specifically: glomerulosclerosis, arteriosclerosis, interstitial fibrosis, and tubular atrophy. Glomerular volume was determined using the Weibel and Gomez method. Associations between these parameters and both estimated glomerular filtration rate (eGFR) and albumin-creatinine ratio (ACR) were determined using either a Mann-Whitney U-test or a Kruskal-Wallis ANOVA. Associations between both eGFR and ACR and glomerular volume were assessed using linear regression. eGFR was inversely associated with the degree of glomerulosclerosis (p < 0.001), vascular narrowing (p= 0.002), tubular atrophy (p < 0.001), and interstitial fibrosis (p < 0.001). ACR was associated only with the degree of interstitial fibrosis (p= 0.02) and tubular atrophy (p= 0.02). Glomerular volume was greater for males, diabetics, hypertensive patients, and patients with a greater degree of interstitial fibrosis. Glomerular volume was positively associated with ACR. A schema to grade chronic damage was developed. The proposed schema is associated with baseline clinical indices of kidney function and damage. Longitudinal validation is necessary to determine the prognostic utility of this schema.

Visceral obesity in Asian living kidney donors significantly impacts early renal function after donor nephrectomy.

Obesity may be a risk factor for kidney donors to develop reduced renal function. The Framingham heart study suggested that visceral adipose tissue (VAT) confers a more adverse metabolic profile compared with subcutaneous adipose tissue (SAT). Asians tend to have a higher VAT composition and it is unclear if their kidney function is affected differently. We hypothesized that Asian living kidney donors who have visceral obesity are at a higher risk of renal function deterioration 1year after donation. Between 2011 and 2014, we retrospectively evaluated data from 73 consecutive patients (52% male; mean age 44.9 ± 11.7years) before they underwent donor nephrectomy and at their 1year routine follow-up. VAT and SAT were measured at the level of the umbilicus on pre-operative computerized tomography (CT). Visceral obesity (VO) was defined as a VAT > 100cm [2] and patients were then further divided and compared in two subgroups: VAT > 100 and < 100cm [2]. Estimated glomerular filtration rate (eGFR, mL/min per 1.73m [2]) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation pre-operatively and 1year post-operatively. Both subgroups had similar baseline kidney function (P = NS) pre-operatively. At the 1year follow-up, patients with VO experienced a more significant decline of renal function (109 ± 9 to 89 ± 8mL/min per 1.73m2), compared to those without VO (111 ± 12 to 96 ± 11mL/min per 1.73m2, P = 0.013). VO was associated with a body mass index (BMI) > 25kg/m2 (P < 0.001), male gender (P < 0.001) and older age at the time of donor nephrectomy (48.0 vs 39.5years, P = 0.01). The presence of hypertension or hyperlipidaemia pre-operatively, choice of surgical approach, and post-operative complication rates, did not differ significantly between the subgroups. Visceral obesity as defined by VAT > 100cm2 at the level of the umbilicus on cross-sectional imaging, may have a significant impact on early renal function after donor nephrectomy. Adiposity markers, as measured by cross-sectional CT imaging, may be incorporated into routine pre-operative kidney donor workup.

Hyperchloremia and postoperative acute kidney injury: a retrospective analysis of data from the surgical intensive care unit

BackgroundWhether perioperative hyperchloremia can induce postoperative acute kidney injury (AKI) is controversial. We investigated the association between perioperative hyperchloremia and postoperative AKI in patients admitted to the intensive care unit (ICU) after surgery.MethodsWe performed a retrospective observational study of patients admitted to the surgical ICU at a single tertiary care hospital between January 2011 and June 2016. Our primary objective was to determine whether hyperchloremia or an increase in serum chloride levels was associated with postoperative AKI. Perioperative hyperchloremia was defined as serum chloride levels ≥ 110 mmol·L− 1 during postoperative days (PODs) 0–3. The increase in serum chloride levels was defined as the difference between preoperative and maximum postoperative serum chloride levels during the first 3 days after surgery.ResultsOf the 7991 patients included in the final analysis, 1876 (23.5%) developed hyperchloremia during PODs 0–3, and 1187 (14.9%) developed postoperative AKI. Exposure to hyperchloremia during the first 3 days after surgery was not associated with postoperative AKI (odds ratio, 1.09; 95% confidence interval, 0.80–1.49; P = 0.571). However, among patients with preoperative chronic kidney disease stage ≥ 3 (estimated glomerular filtration rate < 60 mL·min− 1·1.73·m− 2), the incidence of postoperative AKI was higher in patients with an increase > 6 mmol·L− 1 in serum chloride levels than in patients with an increase ≤ 1 mmol·L− 1 (odds ratio, 1.42; 95% confidence interval, 1.09–1.84; P = 0.009). In addition, the incidence of postoperative AKI stage ≥ 2 was not associated with exposure to hyperchloremia or with the increase in serum chloride levels during PODs 0–3, regardless of preoperative kidney function.ConclusionsExposure to perioperative hyperchloremia is not associated with postoperative AKI in surgical ICU patients. However, in patients with moderate-to-severe chronic kidney disease (stage ≥ 3), a substantial perioperative increase in serum chloride levels may reflect a higher risk of AKI.

A0867 Association between Preoperative Renin-Angiotensin System Inhibitor Use and Postoperative Acute Kidney Injury Risk in Patients with Hypertension

A0867 Association between Preoperative Renin-Angiotensin System Inhibitor Use and Postoperative Acute Kidney Injury Risk in Patients with Hypertension