Preoperative Kidney Research Articles

Association between Changes in Preoperative Serum Creatinine and Acute Kidney Injury after Cardiac Surgery: A Retrospective Cohort Study

Plain Language SummaryCardiac surgery-related acute kidney injury (CSA-AKI) is serious complication that can result in higher mortality and morbidity after cardiac surgery. Although previous studies have highlighted that preoperative kidney dysfunction is a risk factor for AKI, there is limited information of the impact of preoperative serum creatinine change preceding surgery on CSA-AKI. We found that approximately 85% of patients experienced elevation in preoperative serum creatinine. Elevation in preoperative serum creatinine was associated with CSA-AKI, even mild elevation was associated with a 3.8-fold higher risk of postoperative CSA-AKI. Furthermore, patients with pronounced elevation in preoperative serum creatinine also exhibited a higher risk of severe AKI and non-recovery from AKI. This study emphasizes the importance of extending scrutiny beyond mere preoperative serum creatinine values, highlighting the assessment of fluctuations in preoperative serum creatinine; this aids in identifying individuals at high risk, enabling clinicians to intervene more earlier and potentially improve prognosis.

Association of chronic kidney disease with postoperative outcomes: a national surgical quality improvement program (NSQIP) multi-specialty surgical cohort analysis

BackgroundChronic kidney disease (CKD) is associated with higher incidence of major surgery. No studies have evaluated the association between preoperative kidney function and postoperative outcomes across a wide spectrum of procedures. We aimed to evaluate the association between CKD and 30-day postoperative outcomes across surgical specialties.MethodsWe selected adult patients undergoing surgery across eight specialties. The primary study endpoint was major complications, defined as death, unplanned reoperation, cardiac complication, or stroke within 30 days following surgery. Secondary outcomes included Clavien-Dindo high-grade complications, as well as cardiac, pulmonary, infectious, and thromboembolic complications. Multivariable regression was performed to evaluate the association between CKD and 30-day postoperative complications, adjusted for baseline characteristics, surgical specialty, and operative time.ResultsIn total, 1,912,682 patients were included. The odds of major complications (adjusted odds ratio [aOR] 2.14 [95% confidence interval (CI): 2.07, 2.21]), death (aOR 3.03 [95% CI: 2.88, 3.19]), unplanned reoperation (aOR 1.57 [95% CI: 1.51, 1.64]), cardiac complication (aOR 3.51 [95% CI: 3.25, 3.80]), and stroke (aOR 1.89 [95% CI: 1.64, 2.17]) were greater for patients with CKD stage 5 vs. stage 1. A similar pattern was observed for the secondary endpoints.ConclusionThis population-based study demonstrates the negative impact of CKD on operative outcomes across a diverse range of procedures and patients.

The role of artificial intelligence measured preoperative kidney volume in predicting kidney function loss in elderly kidney donors: A multicenter cohort study.

The increasing use of kidneys from elderly donors raises concerns due to age-related nephron loss. Combined with nephrectomy, this loss of nephrons markedly increases the risk of developing chronic kidney disease (CKD). This study aimed to investigate the prognostic value of preoperative kidney cortex volume in predicting the loss of kidney function in elderly donors, by developing an artificial intelligence (AI)-based model for precise kidney volume measurement and applying it to living kidney donors. A multicenter retrospective cohort study using data from living donors who underwent donor nephrectomy between January 2010 and December 2020 was conducted. An AI segmentation model was developed and validated to measure kidney cortex volume from pre-donation computer tomographic (CT) images. The association between measured preoperative kidney volumes and post-nephrectomy renal function was analyzed through a generalized additive model. A total of 1074 living kidney donors were included in the study. Validation of the developed kidney cortex volume model showed a Dice similarity coefficient of 0.97 and a Hausdorff distance of 0.76mm. The measured cortex volumes exhibited an age-related decrease, which correlated with declining kidney function. Elderly donors showed greater decreases in estimated glomerular filtration rates (eGFR) post-donation compared to young donors (P=0.041). Larger preoperative remnant kidney cortex volume was associated with significantly less decline of eGFR post-donation than those with smaller preoperative remnant kidney cortex volume (P<0.001). This study highlights the critical role of preoperative kidney cortex volume in the donor assessment process, particularly for elderly donors. The fully automated model for measuring kidney cortex volume provides a valuable tool for predicting post-donation renal function and holds promise for enhancing donor evaluation and safety.

Hematocrit and Renal Failure in Aortic Arch Surgery: A Society of Thoracic Surgeons Database Study

BackgroundThis study examined the association between cardiopulmonary bypass (CPB) hematocrit and postoperative acute renal failure (ARF) in patients undergoing aortic arch surgery with hypothermic circulatory arrest. MethodsThe Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried from 2011 to 2019 for patients undergoing aortic arch surgery with hypothermic circulatory arrest. A multivariable logistic regression model estimated the adjusted odds of postoperative ARF on the basis of CPB hematocrit. Effects were stratified by preoperative kidney function and the duration of hypothermic circulatory arrest by using interaction terms. The study also investigated the association between postoperative ARF and major postoperative outcomes by using multivariable regression models. ResultsOn adjusted analysis, higher CPB hematocrit (>20%-25%, >25%-30%, >30%) was associated with lower odds of ARF as compared with lower CPB hematocrit (≤20%) (>20-25%, aOR, 0.78; 95% CI, 0.65-0.93; P = .006; >25%-30%, aOR, 0.65; 95% CI, 0.50-0.84; P = .0007; >30%, aOR, 0.45; 95% CI, 0.28-0.72; P = .0008). The predicted probability of postoperative ARF by CPB hematocrit was higher in patients with lower preoperative renal function (estimated glomerular filtration rate, <60 mL/min/1.73 m2) (interaction P = .03). The association between hematocrit and postoperative ARF was not significantly modified by hypothermic circulatory arrest time (interaction P = .74). All postoperative outcomes were significantly worse in patients with postoperative ARF (all P < .0001). ConclusionsAmong patients undergoing aortic arch surgery, a higher CPB hematocrit level is associated with reduced likelihood of postoperative ARF. Preoperative renal function, but not hypothermic circulatory arrest duration, significantly modified this association. The maintenance of higher CPB hematocrit may reduce the incidence of postoperative ARF, especially for patients with poor preoperative renal function.

CT imaging analysis differentiating papillary renal neoplasm with reverse polarity from papillary renal cell carcinoma: combined with a radiomics model.

To assess the computed tomography (CT) findings of papillary renal neoplasm with reverse polarity (PRNRP) and develop a radiomics-based model to distinguish PRNRPs from papillary renal cell carcinomas (PRCCs). We analyzed 31 PRNRPs and 68 PRCCs using preoperative kidney CT. We evaluated CT features that could discriminate PRNRPs from PRCCs. A radiomics signature was constructed using features selected through a least absolute shrinkage and selection operator algorithm. A radiomics-based model incorporating a radiomics signature and subjective CT parameters using multivariate logistic regression was developed. The diagnostic performance of the CT parameters, radiomics model, and their combination was evaluated using the area under the curve (AUC). Most of PRNRPs had a round shape (93.5%), well-defined margin (100%), and persistent enhancement (77.4%). Compared with PRCC, PRNRPs exhibited distinct CT features including small size (16.7 vs. 37.7mm, P < 0.001), heterogeneity (64.5 vs. 32.4%, P = 0.004), enhancing dot sign (16.1 vs. 1.5%, P = 0.001), and high attenuation in pre-contrast CT (44.2 vs. 35.5 HU, P = 0.003). Multivariate analysis revealed smaller mass size (odds ratio [OR]: 0.9; 95% confidence interval [CI] 0.9-1.0, P = 0.013), heterogeneity (OR: 8.8; 95% CI 1.9-41.4, P = 0.006), and higher attenuation in pre-contrast CT (OR: 1.1; 95% CI 1.0-1.2, P = 0.011) as significant independent factors for identifying PRNRPs. The diagnostic performance of the combination model was excellent (AUC: 0.923). Smaller tumor size, heterogeneity, and higher attenuation in pre-contrast CT were more closely associated with PRNRPs than with PRCCs. Though the retrospective design, small sample size, and single-center data of this study may affect the generalizability of the findings, combining subjective CT features with a radiomics model is beneficial for distinguishing PRNRPs from PRCCs.

Impact of diabetic kidney disease on post-operative complications after primary elective total hip arthroplasty: a nationwide database analysis

BackgroundThe high prevalence of diabetic kidney disease (DKD) in the United States necessitates further investigation into its impact on complications associated with total hip arthroplasty (THA). This study utilizes a large nationwide database to explore risk factors in DKD cases undergoing THA.MethodsThis research utilized a case–control design, leveraging data from the national inpatient sample for the years 2016 to 2019. Employing propensity score matching (PSM), patients diagnosed with DKD were paired on a 1:1 basis with individuals free of DKD, ensuring equivalent age, sex, race, Elixhauser Comorbidity Index (ECI), and insurance coverage. Subsequently, comparisons were drawn between these PSM-matched cohorts, examining their characteristics and the incidence of post-THA complications. Multivariate logistic regression analysis was then employed to evaluate the risk of early complications after surgery.ResultsDKD's prevalence in the THA cohort was 2.38%. A 7-year age gap separated DKD and non-DKD patients (74 vs. 67 years, P < 0.0001). Additionally, individuals aged above 75 exhibited a substantial 22.58% increase in DKD risk (49.16% vs. 26.58%, P < 0.0001). Notably, linear regression analysis yielded a significant association between DKD and postoperative acute kidney injury (AKI), with DKD patients demonstrating 2.274-fold greater odds of AKI in contrast with non-DKD individuals (95% CI: 2.091–2.473).ConclusionsThis study demonstrates that DKD is a significant risk factor for AKI in patients undergoing total hip arthroplasty. Optimizing preoperative kidney function through appropriate interventions might decrease the risk of poor prognosis in this population. More prospective research is warranted to investigate the potential of targeted kidney function improvement strategies in reducing AKI rates after THA. The findings of this study hold promise for enhancing preoperative counseling by surgeons, enabling them to provide DKD patients undergoing THA with more precise information regarding the risks associated with their condition.

#2871 Effect of parathyroidectomy on kidney function in adults with primary hyperparathyroidism

Abstract Background and Aims Multidisciplinary guidelines recommend parathyroidectomy to slow the progression of chronic kidney disease in patients with primary hyperparathyroidism (PHPT) and an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2. However, this is a weak recommendation, based on low-quality evidence. The objective of this study was to evaluate the estimated glomerular filtration rate change 12 months after parathyroidectomy for primary hyperparathyroidism according to preoperative kidney function. Method Patients who underwent parathyroidectomy for PHPT between 2017 and 2020 were retrospectively enrolled (n = 90). Patients without 1-year follow-up or with missing data were excluded (n = 42). Patients were dichotomized according to their baseline eGFR: &amp;lt; 60 mL/min (group 1; n = 13) and ≥60 mL/min (group 2; n = 35). Variables were measured before and then at 12 months after parathyroidectomy. Statistical analyses was made using SPSS 28. Results The cohort included 38 female patients (79.2%) with a mean age of 68.4 ± 11.27 years. Hypertension was present in 36 patients (75%) and 16 patients (33.3%) were diabetic. Thirty-two patients were being treated with ACEI/ARAII. The mean baseline eGFR was 44.6 ± 9.5 mL/min and 88.0 ± 12.7 mL/min in groups 1 and 2, respectively. Group 1 patients had a higher median baseline serum parathyroid hormone level (p = 0.002). At 12 months, all patients were normocalcemic. The eGFR decreased significantly after parathyroidectomy in group 2 (−5.8 mL/min, p = 0.012), while in group 1 the eGFR remain stable (−0.46 mL/min, p = 0.931). We didn't find any predictive factor of eGFR variation. Conclusion Further studies are needed to understand the progression of renal disease after parathyroidectomy. The etiology of the disease, the use of nephroprotective measures or in the other hand nephrotoxins may have an higher impact than restore normocalcemia alone.

Sex bias in prediction and diagnosis of cardiac surgery associated acute kidney injury

BackgroundFemale sex has been recognized as a risk factor for cardiac surgery associated acute kidney injury (CS-AKI). The current study sought to evaluate whether female sex is a risk factor for CS-AKI, or modifies the association of peri-operative change in serum creatinine with CS-AKI.MethodsObservational study of adult patients undergoing cardiac surgery between 2000 and 2019 in a single U.S. center. The main variable of interest was registered patient sex, identified from electronic medical records. The main outcome was CS-AKI within 2 weeks of surgery.ResultsOf 58526 patients, 19353 (33%) were female; 12934 (22%) incurred AKI based on ≥ 0.3 mg/dL or ≥ 50% rise in serum creatinine (any AKI), 3320 (5.7%) had moderate to severe AKI, and 1018 (1.7%) required dialysis within 2 weeks of surgery. Female sex was associated with higher risk for AKI in models that were based on preoperative serum creatinine (OR, 1.35; 95% CI, 1.29–1.42), and lower risk with the use of estimated glomerular filtration, (OR, 0.90; 95% CI, 0.86–0.95). The risk for moderate to severe CS-AKI for a given immediate peri-operative change in serum creatinine was higher in female compared to male patients (p < .0001 and p < .0001 for non-linearity), and the association was modified by pre-operative kidney function (p < .0001 for interaction).ConclusionsThe association of patient sex with CS-AKI and its direction was dependent on the operational definition of pre-operative kidney function, and differential outcome misclassification due to AKI defined by absolute change in serum creatinine.

Impact of kidney disease on perioperative outcomes of endoscopic BPH surgery: a propensity score matched analysis from the NSQIP database.

To assess the impact of kidney function in patients with BPH undergoing surgery prior to Transurethral resection of prostate (TURP), Laser enucleation of the prostate (LEP), and Laser Vaporization of the prostate (LVP) on operative and post-operative outcomes using the ACS-NSQIP database. The ACS-NSQIP database was reviewed for patients that underwent TURP, LEP and LVP for treatment of patients with BPH between the years of 2008 and 2021. Demographics, comorbidities, bleeding disorders, operative time, and surgical procedure performed were collected for comparison between Kidney function groups: G1, normal/high function; G2-G3, mild/moderate kidney disease; and G4-G5, severe kidney disease. The 30-day peri-operative complications were measured and a multivariate logistic regression analysis was performed while adjusting for all confounding variables. Propensity score matching was performed between the G1 and G4-G5 cohorts. A total of 83,020 patients were included. On multivariable regression, in the G2-G3 cohort, patients were at significantly increased risk for renal complications with OR = 2.43[1.56-3.79]. After propensity score matching, the G4-G5 cohort showed increased odds of pneumonia OR = 4.02[1.343-12.056], renal complications with OR = 7.62[2.283-25.411], cardiac complications OR = 4.53[1.531-13.411], and sepsis/septic shock OR = 1.76[1.091-2.834]. They also had a higher need for blood transfusion OR = 3.58[2.242-5.714], and prolonged hospital stay with OR = 1.49[1.296-1.723]. Pre-operative kidney disease may pose an increased risk of complications for patients undergoing endoscopic BPH surgery. The literature lacks information on the effect of pre-operative kidney disease on endoscopic BPH surgeries. Further studies are required to compare post-operative outcomes of LEP and LVP as compared to TURP across kidney function status.

SINGLE CENTER EXPERIENCE IN SURGICAL TREATMENT FOR ACTIVE ENDOCARDITIS BEFORE AND AFTER COVID–19 PANDEMIC

Abstract Background Despite advanced diagnosis and treatment, infective endocarditis (IE) is a potentially life–threatening condition. The impact of COVID–19 on diagnosis and outcome of surgical treatment of IE is uncertain. The aim of this study was to analyze the incidence, characteristics and outcomes of surgically treated IE before and after the COVID–19 pandemic. Methods This study retrospectively analyzed data of 536 patients who underwent valve surgical procedures for IE between January 2010 and December 2022 in a single cardiac surgery center. Patients were divided in two groups depending on the date of operation: before (n=393) and after (n=142) COVID–19 onset. In order to balance the groups, inverse probability of treatment weighting (IPTW) calculated from the propensity score (PS) was applied. Results We noticed a significant increase (p=0.006) in the prevalence of infective endocarditis admitted for surgery throughout the years, comparing it to overall hospitalizations in our cardiac surgery department (Figure 1). Patients from the post COVID cohort (after march 2020) had more comorbidities such as diabetes (29.6% vs 16.3% p=0.001), hypertension (71.1% vs 59.5% p=0.015), and preoperative kidney injury requiring dialysis (9.2% vs 2.5% p=0.002), but median additive and logistic Euroscore were not statistically different. In the post COVID group, we observed a greater prevalence of S. Aureus related endocarditis (24.5% vs 15.4% p=0.026), and a consequent reduction in S. non Aureus related endocarditis (12.2% vs 20.1% p=0.048) (Figure 2), a decrease of aortic valve replacement (43.0% vs 53.9%), while the number of mitral valve replacement ad repair resulted to be higher (21.1% vs 15.0% and 6.3% vs 4.3% respectively) (Figure 3). No differences in the two groups concerning early death but also death or relapse at one year after surgery. Data obtained by the multivariable analysis identify the preoperative renal dysfunction requiring dialysis as the only common risk factor for early mortality stratifying by time periods in analysis. Conclusions The incidence of surgical treated IE significant increase after COVID–19 pandemic with a higher incidence of mitral involvement instead of aortic valve. Despite the pandemic and the delay in surgical timing, results in terms of mortality and outcomes have improved and were largely unaffected by the COVID–19 pandemic.

Kidney Function Trajectories and Right Heart Failure Following LVAD Implantation.

Preoperative kidney dysfunction is a risk factor for right heart failure (RHF) after implantation of a left ventricular assist device (LVAD). However, characteristic kidney function trajectories before and after post-LVAD RHF are uncertain, so we investigated this. We identified individuals who received primary continuous-flow LVAD implantation from July 1, 2014 to December 31, 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data set. Incident RHF was ascertained using the INTERMACS definition at 1 and 3 months and classified as transient or persistent. Kidney function trajectories before and after RHF onset, and relationships of baseline kidney function with RHF risk at the different time points, were assessed. We identified 8076 LVAD recipients who met inclusion criteria. Incident RHF was present at 1 month in 26.4%. There were 4850 individuals with follow-up at 3 months, with incident RHF in 4.2%. Kidney function trajectories differed from pre-LVAD implantation to 1-month follow-up by RHF category, with those developing persistent RHF having no improvement in baseline kidney function. For trajectories before the 3-month RHF ascertainment time, the shape was similar for those with and without RHF, with lower estimated glomerular filtration rate levels among those who developed RHF. Baseline estimated glomerular filtration rate levels below the normal range were associated with higher risk of RHF at 1 and 3 months. In LVAD recipients, preimplantation kidney function and subsequent kidney function trajectories differed substantially by RHF at 1 and 3 months postimplantation, even after adjustment for several confounders. This may demonstrate bidirectional associations between kidney function and right ventricular function in LVAD recipients.

Comparison of Oncological and Functional Outcomes of Radical Versus Partial Nephrectomy for cT1b Renal Cell Carcinoma: A Two-Centre, Matched Analysis

BACKGROUND: It remains unclear which patients with cT1b renal cell carcinoma (RCC) benefit most from partial nephrectomy (PN) versus radical nephrectomy (RN) considering oncological outcomes and renal function. OBJECTIVE: To compare oncological and functional outcomes of RN with PN for cT1b RCC. METHODS: This is a retrospective analysis of patients who underwent RN or PN for cT1b between 2010 and 2022 (n = 241). Patients were grouped by RN or PN and matched by age, sex, Charlson Comorbidity Index, BMI, PADUA score, RENAL score, ASA score, and preoperative kidney function (eGFR) using propensity score matching. The 10-year overall survival (OS), 10-year cancer-specific survival (CSS), and 10-year recurrence-free survival (RFS) were compared. Change in eGFR from baseline to 5-year follow-up was assessed. RESULTS: After matching, 100 patients remained in each group for analysis. The 10-year OS, CSS, and RFS rates were similar between groups. For patients classified as low risk, the PN group displayed a higher recurrence rate compared to RN (7 vs. 0, p = 0.01). Patients who underwent RN had worse 1-year postoperative eGFR than PN (RN: 57 [44–65], PN: 73 [60–87], p &lt; 0.001). RN was more likely to induce new-onset chronic kidney disease (CKD) stage ≥3b compared to PN (p &lt; 0.001). Complication rate after PN was significantly higher (p = 0.003). CONCLUSION: 10-year survival rates were similar, despite more recurrences in the PN group. Our data shows that post-surgical renal function is superior for PN. Nevertheless, RN is a reliable treatment option when preservation of renal function is not a priority.

Severe Acute Kidney Injury Postheart Transplantation: Analysis of Risk Factors.

Acute kidney injury (AKI) is a common complication postheart transplantation and is associated with significant morbidity and increased mortality. We conducted a single-center, retrospective, observational cohort study of 109 consecutive patients undergoing heart transplantation between September 2019 and September 2021 to determine major risk factors for, and the incidence of, severe postoperative AKI as defined by Kidney Disease Improving Global Outcomes criteria in the first 48-h posttransplantation and the impact that this has on mortality and dialysis dependence. One hundred nine patients were included in our study, 83 of 109 (78%) patients developed AKI, 42 (39%) developed severe AKI, and 37 (35%) required renal replacement therapy in the first-week posttransplantation. We found preoperative estimated glomerular filtration rate (eGFR), postoperative noradrenaline dose, and the need for postoperative mechanical circulatory support to be independent risk factors for the development of severe AKI. Patients who developed severe AKI had a 19% 12-mo mortality compared with 1% for those without. Of those who survived to hospital discharge, 20% of patients in the severe AKI group required dialysis at time of hospital discharge compared with 3% in those without severe AKI. Severe AKI is common after heart transplantation. Preoperative kidney function, postoperative vasoplegia with high requirements for vasoactive drugs, and graft dysfunction with the need for mechanical circulatory supports were independently associated with the development of severe AKI in the first-week following heart transplantation. Severe AKI is associated with a significantly increased mortality and dialysis dependence at time of hospital discharge.

Surgical Treatment of Active Endocarditis Pre- and Post-COVID-19 Pandemic Onset.

Despite advanced diagnosis and treatment, infective endocarditis (IE) is a potentially life-threatening condition. The impact of COVID-19 on the diagnosis and outcome of the surgical treatment of IE is uncertain. The aim of this study was to analyze the incidence, characteristics, and outcomes of surgically treated IE before and after the COVID-19 pandemic. This study retrospectively analyzed the data of 535 patients who underwent valve surgical procedures for IE between January 2010 and December 2022 in a single cardiac surgery center. Patients were divided into two groups depending on the date of their operation: before (n = 393) and after (n = 142) COVID-19 onset. In order to balance the groups, inverse probability of treatment weighting (IPTW) calculated from the propensity score (PS) was applied. Weighted univariate logistic regressions were reported for outcomes; weights were derived from IPTW. Interrupted time series analysis (ITSA) according to Linden's method was used to evaluate the changes in the manifestation of IE after 11 March 2020. Patients from the post-COVID-19 cohort (after 11 March 2020) had a greater number of comorbidities such as diabetes (29.6% vs. 16.3% p = 0.001), hypertension (71.1% vs. 59.5% p = 0.015), and preoperative kidney injury requiring dialysis (9.2% vs. 2.5% p = 0.002), but the median additive and logistic EuroSCORE were not statistically different. In the post-COVID-19 group, we observed a greater prevalence of Staphylococcus aureus-related endocarditis (24.5% vs. 15.4% p = 0.026), a consequent reduction in Staphylococcus non aureus-related endocarditis (12.2% vs. 20.1% p = 0.048), and a decrease in aortic valve replacements (43.0% vs. 53.9%), while the number of mitral valve replacements and repair was greater (21.1% vs. 15.0% and 6.3% vs. 4.3%, respectively). No differences were found in the two groups concerning early death, death, or relapse at 1 year after surgery. Data obtained by multivariable analysis identified preoperative renal dysfunction requiring dialysis as the only common risk factor for early mortality via stratifying by time periods in analysis. The incidence of surgically treated IE significantly increases after the COVID-19 pandemic with a higher incidence of mitral valve involvement with respect to the aortic valve. Although a delay in surgical timing occurred during the COVID-19 pandemic, data in terms of mortality and outcomes were largely unaffected.

Cystatin C or creatinine for pre-operative assessment of kidney function and risk of post-operative acute kidney injury: a secondary analysis of the METS cohort study.

Post-operative acute kidney injury (PO-AKI) is a common surgical complication consistently associated with subsequent morbidity and mortality. Prior kidney dysfunction is a major risk factor for PO-AKI, however it is unclear whether serum creatinine, the conventional kidney function marker, is optimal in this population. Serum cystatin C is a kidney function marker less affected by body composition and might provide better prognostic information in surgical patients. This was a pre-defined, secondary analysis of a multi-centre prospective cohort study of pre-operative functional capacity. Participants were aged ≥40years, undergoing non-cardiac surgery. We assessed the association of pre-operative estimated glomerular filtration rate (eGFR) calculated using both serum creatinine and serum cystatin C with PO-AKI within 3days after surgery, defined by KDIGO creatinine changes. The adjusted analysis accounted for established AKI risk factors. A total of 1347 participants were included (median age 65years, interquartile range 56-71), of whom 775 (58%) were male. A total of 82/1347 (6%) patients developed PO-AKI. These patients were older, had higher prevalence of cardiovascular disease and related medication, were more likely to have intra-abdominal procedures, had more intraoperative transfusion, and were more likely to be dead at 1year after surgery 6/82 (7.3%) vs 33/1265 (2.7%) (P=.038). Pre-operative eGFR was lower in AKI than non-AKI patients using both creatinine and cystatin C. When both measurements were considered in a single age- and sex-adjusted model, eGFR-Cysc was strongly associated with PO-AKI, with increasing risk of AKI as eGFR-Cysc decreased below 90, while eGFR-Cr was no longer significantly associated. Data from over 1000 prospectively recruited surgical patients confirms pre-operative kidney function as major risk factor for PO-AKI. Of the kidney function markers available, compared with creatinine, cystatin C had greater strength of association with PO-AKI and merits further assessment in pre-operative assessment of surgical risk.

The Impact of Early-Stage Chronic Kidney Disease on Weight Loss Outcomes After Gastric Bypass

PurposeWeight loss achieved through bariatric metabolic surgery was demonstrated to be effective at reversing chronic kidney dysfunction associated with obesity-related glomerulopathy. However, robust data on how pre-operative kidney status impacts on bariatric metabolic surgery weight loss outcomes is still lacking. The aim of this study was to evaluate the impact of kidney dysfunction on weight loss outcomes after bariatric metabolic surgery.MethodsPatients with obesity to be submitted to gastric bypass surgery underwent a pre-operative evaluation of creatinine clearance, estimated glomerular filtration rate (eGFR), proteinuria, and albuminuria in 24-hour urine. Body mass index (BMI), % total weight loss (%TWL), and % excess BMI loss (%EBMIL) were assessed at 6 and 12 months after surgery.ResultsBefore surgery, patients (N=127) had a mean BMI of 39.6 ± 3.0 kg/m2, and 56.7% (n=72) had a creatinine clearance > 130 mL/min, 23.6% (n= 30) presented proteinuria > 150 mg/24h, and 15.0% (n= 19) presented albuminuria > 30 mg/24h. After surgery, the mean BMI was 27.7 kg/m2 and 25.0 kg/m2 at 6 and 12 months, respectively (p<0.0001). The %TWL was lower in patients with pre-operative eGFR < percentile 25 (34.4 ± 5.8% vs 39.4 ± 4.9%, p=0.0007, at 12 months). There were no significant correlations between weight loss metrics and pre-operative creatinine clearance rate, proteinuria, or albuminuria.ConclusionEarly-stage chronic kidney disease (G2) has a negative impact on short-term weight loss outcomes after bariatric metabolic surgery, albeit in a magnitude inferior to the clinically relevant threshold.Graphical abstract

The epidemiology and outcomes of acute kidney injury following orthopaedic procedures: A retrospective cohort study.

Acute kidney injury (AKI) is a serious complication following major surgery. This study examined the incidence and risk factors of AKI following orthopaedic surgeries in an Icelandic cohort, as well as the association between AKI and patient- and surgery-related factors. This retrospective cohort study comprised all patients 18 years and older who underwent orthopaedic surgeries at Landspitali - The National University Hospital in the years 2006-2018 with available serum creatinine (SCr) measurements adjacent to the surgery to stage AKI. AKI was defined according to SCr portion of the KDIGO criteria. Logistic regression was used to identify patient- and surgical factors related to progression of AKI and Poisson-regression was used to explore changes in incidence. A total of 222 cases of AKI following 3208 surgeries (6.9%) were identified in the study period with a rise in the incidence by about 17% per year. Higher age (odds ratio (OR), 1.02, 95% confidence interval (CI), 1.01-1.04 per year) and underlying reduction in kidney function (OR 1.93 (1.30-2.81), 3.24 (2.08-4.96) and 4.08 (2.35-6.96) for estimated glomerular filtration rate (eGFR) of 30-59, 15-29 and <15 mL/min/1.73 m2 compared with eGFR >60 mL/min/1.73 m2 ) were associated with higher risk of AKI, but female sex was associated with decreased odds (OR = 0.73; 95% CI, 0.54-0.98). After correcting for age, sex, preoperative kidney function, emergency surgery and underlying comorbidities and frailty, there was an increased risk of long-term mortality in patients with AKI (HR 1.41, 95% CI 1.08-1.85), and patients who developed AKI also had accelerated progression of chronic kidney disease compared with patients who did not develop AKI. The incidence of AKI following orthopaedic surgeries is increasing and is associated with adverse outcomes. It is important that elderly individuals and patients who have reduced kidney function receive adequate monitoring and surveillance in the perioperative period.

Preoperative chronic kidney disease and complications after pancreatoduodenectomy: a retrospective cohort study.

Chronic kidney disease is a prevalent condition in surgical patients. Possible associations with increased postoperative morbidity and mortality have not been clearly demonstrated in patients undergoing pancreatoduodenectomy. The aim of this study was to assess the risk of postoperative complications in patients with reduced kidney function undergoing pancreatoduodenectomy. All patients undergoing pancreatoduodenectomy at Karolinska University Hospital between 2008 and 2019 were retrospectively included. The variable of interest was chronic kidney disease, based on preoperative estimated glomerular filtration rate measurements. Unadjusted and adjusted logistic regression analyses were performed for standardized postoperative complications. A total of 971 patients were included in the study, of whom 92 (10%) had an estimated glomerular filtration rate < 60 mL/min/1.73m2 , equivalent to chronic kidney disease Stage 3a or worse. Patients with chronic kidney disease had a higher odds of longer hospital stay (adjusted odds ratio 1.58, 95% confidence interval 1.00-2.50) and postoperative weight increase (adjusted odds ratio 2.02, 1.14-3.56). A 10 unit increase of preoperative estimated glomerular filtration rate was associated to lower odds of intensive care unit admission (adjusted odds ratio 0.81, 0.69-0.95), delayed gastric emptying (adjusted odds ratio 0.90, 0.81-0.99), and post-operative pancreatic fistula (adjusted odds ratio 0.83, 0.74-0.94). Patients undergoing pancreatoduodenectomy with decreased preoperative kidney function are more likely to experience major postoperative complications, and also postoperative weight increase. Preoperative kidney function assessment is important in risk stratification before pancreatoduodenectomies.

Acute Kidney Injury After Liver Transplantation: Incidence, Risk Factors, and Outcomes

Introduction: Although numerous risk factors for acute kidney injury (AKI) have been identified, their cumulative impact remains unclear. This study aimed to identify perioperative risk factors for early post-transplant AKI on patients and outcomes and to predict AKI using clinical variables.&#x0D; Material and Methods: A single-center, retrospective cohort study involving 34 pediatric patients and 31 adults who underwent LT between 2015 and 2017.&#x0D; Results: AKI occurred in 16 (47%) pediatric patients during the first-week post-LT with stage 1, stage 2, and stage 3 AKI frequencies of 43.8, 50, and 6.3%, respectively. Renal replacement therapy (RRT) was initiated in 18.8% of pediatric LT patients. Preoperative liver enzymes and the etiology of liver failure are the most critical factors affecting AKI in pediatric LT patients. AKI occurred in 15 (48%) adult patients during the first-week post-LT with stage 1, stage 2, and stage 3 AKI frequencies of 43%, 21%, and 21%, respectively. The requirement for RRT was seen in 43% of adult LT patients. There were also statistical differences between the two groups regarding the number of patients with preoperative kidney dysfunction (20-80%, p=.047) and mortality rates (6-31 %, p=.047). In adult patients who developed post-LT AKI compared with those who did not develop post-LT AKI, they had significantly higher levels of serum creatinine (sCr) (1.9±1.9 mg/dL vs. 0.7±0.1 mg/dL, p=.013), were given lower amounts of crystalloids (73±32 mL/kg vs. 106±33 mL/kg, p=.018) and had lower urine output (UO) intraoperatively (11±9 mL/kg vs. 20±9 mL/kg, p=.047). There was a higher mortality rate in adult patients with post-LT AKI (89 vs. 11%, p=.003).&#x0D; Conclusion: The results of our study contribute to raising awareness of the potential risk factors associated with preoperative evaluation, intraoperative and postoperative close follow-up, careful anesthesia management, and early onset of post-LT AKI.

The impact of preoperative kidney replacement therapy on kidney outcome and survival in patients with left ventricular assist device

Left ventricular assist device (LVAD) has been highlighted as a new treatment option in the end-stage heart failure (HF). Kidney outcome after LVAD in severe cardiorenal syndrome (CRS) patients requiring kidney replacement therapy (KRT) is unclear. We investigated the impact of preoperative KRT on kidney function and survival in LVAD patients with severe CRS. A total of 50 patients followed up for at least 1 year after LVAD implantation was analyzed. The primary outcomes were estimated glomerular filtration rate and survival rate. Patients were divided into two groups depending on in-hospital KRT before LVAD implantation: the control group (n = 33) and the KRT group (n = 17). Postoperative KRT was performed for 76.5% of patients in the KRT group, and all of them discontinued KRT before discharge. There were no statistically significant differences in the degree of eGFR decline in survivors according to preoperative KRT. Although there were no statistically significant differences in the degree of eGFR decline in survivors regardless of preoperative KRT, old age (β −0.94, p < 0.01), preexisting chronic kidney disease (β −21.89, p < 0.01), and high serum creatinine (β −13.95, p < 0.01) were identified as independent predictors of post-LVAD eGFR decline. Mortality rate was higher, and more patients progressed to end-stage kidney disease in KRT group than control group. However, LVAD still can be considered as the treatment option in end-stage HF patients with severe CRS requiring KRT, especially in those with young age and previous normal kidney function.