Residual renal function after partial or radical nephrectomy for renal cell carcinoma

Effects of a Personalized Diet on Nutritional Status and Renal Function Outcome in Nephrectomized Patients with Renal Cancer

Nutritional therapy (NT) based on a controlled protein intake represents a cornerstone in managing chronic kidney disease (CKD). However, if a CKD patient is at the same time affected by cancer, oncologists and nutritionists tend to suggest a dietary regimen based on high protein intake to avoid catabolism and malnutrition. International guidelines are not clear when we consider onco-nephrological patients and, as a consequence, no clinical shared strategy is currently applied in clinical practice. In particular, no precise nutritional management is established in nephrectomized patients for renal cell carcinoma (RCC), a specific oncological cohort of patients whose sudden kidney removal forces the remnant one to start a compensatory mechanism of adaptive hyperfiltration. Our study aimed to investigate the efficacy of a low-normal-protein high-calorie (LNPHC) diet based on a Mediterranean model in a consecutive cohort of nephrectomized RCC patients using an integrated nephrologist and nutritionist approach. A consecutive cohort of 40 nephrectomized RCC adult (age > 18) patients who were screened for malnutrition (malnutrition screening tool, MST < 2) were enrolled in a tertiary institution between 2020 and 2022 after signing a specific informed consent form. Each patient underwent an initial nephrological and nutritional evaluation and was subsequently subjected to a conventional CKD LNPHC diet integrated with aproteic foods (0.8 g/Kg/die: calories: 30-35 kcal per kg body weight/die) for a period of 6 months (±2 months). The diet was structured after considering eGFR (CKD-EPI 2021 creatinine formula), comorbidities, and nutritional status. MST, body mass index (BMI), phase angle (PA), fat mass percentage (FM%), fat-free mass index (FFMI), body cell mass index (BCMI), extracellular/intracellular water ratio (ECW/ICW), extracellular matrix/body cell mass ratio (ECM/BCM), waist/hip circumference ratio (WHC), lab test exams, and clinical variables were examined at baseline and after the study period. Our results clearly highlighted that the LNPHC diet was able to significantly improve several nutritional parameters, avoiding malnutrition and catabolism. In particular, the LNPHC diet preserved the BCM index (delta on median, ΔM + 0.3 kg/m2) and reduced the ECM/BCM ratio (ΔM - 0.03 *), with a significant reduction in the ECW/ICW ratio (ΔM - 0.02 *), all while increasing TBW (ΔM + 2.3% *). The LNPHC diet was able to preserve FFM while simultaneously depleting FM and, moreover, it led to a significant reduction in urea (ΔM - 11 mg/dL **). In conclusion, the LNPHC diet represents a new important therapeutic strategy that should be considered when treating onco-nephrological patients with solitary kidney due to renal cancer.

A single-centre retrospective study of factors affecting steroid-free remission of immunoglobulin G4-related disease conducted in South Korea: A notable outcome after complete resection

OBJECTIVES

Few studies have examined factors affecting steroid-free remission (SFR) in patients with immunoglobulin G4-related disease (IgG4-RD). The aim of this study was to investigate clinical factors affecting SFR in IgG4-RD.

METHODS

The medical records of 68 patients who met the 2020 revised comprehensive diagnostic criteria for IgG4-RD were reviewed retrospectively. SFR was defined as remission maintained for at least 6 months without corticosteroids. Cox regression analysis was performed to examine the associations between SFR and various clinical factors. The relapse rate after SFR was examined using the log-rank test.

RESULTS

After a median follow-up of 36 months, 30.9% (21/68) of patients with IgG4-RD achieved SFR. Multivariate Cox regression analysis revealed that IgG4-RD diagnosed by complete resection rather than by common diagnostic procedures was the only factor positively associated with SFR (hazard ratio, 7.41; 95% confidence interval, 2.23-24.60; P = .001). Furthermore, relapse after attainment of SFR was significantly less common in the group that underwent complete resection than in the group that did not undergo complete resection (log-rank P = .006).

CONCLUSIONS

Patients with IgG4-RD diagnosed by complete resection had a higher likelihood of achieving SFR and a lower rate of relapse after attaining SFR.

Respecting living kidney donor autonomy: an argument for liberalising living kidney donor acceptance criteria

Doctors routinely refuse donation offers from prospective living kidney donors with certain comorbidities such as diabetes or obesity out of concern for donor wellbeing. This refusal occurs despite the ongoing shortage of kidney transplants and the superior performance of living donor kidney transplants compared to those from deceased donors. In this paper, we argue that this paternalistic refusal by doctors is unjustified and that, within limits, there should be greater acceptance of such donations. We begin by describing possible weak and strong paternalistic justifications of current conservative donor acceptance guidelines and practices. We then justify our position by outlining the frequently under-recognised benefits and the routinely overestimated harms of such donation, before discussing the need to respect the autonomy of willing donors with certain comorbidities. Finally, we respond to a number of possible objections to our proposal for more liberal kidney donor acceptance criteria. We use the situation in Australia as our case study, but our argument is applicable to comparable situations around the world.

Novel Biomarkers for Early Detection of Acute Kidney Injury and Prediction of Long-Term Kidney Function Decline after Partial Nephrectomy

Background: Identifying acute kidney injury (AKI) within few hours of onset is certainly helpful. However, early prediction of a long-term eGFR decline may be an even more important goal. Our aim was to identify and compare serum [creatinine, kineticGFR, cystatin C, neutrophil gelatinase–associated lipocalin (NGAL)] and urinary (NephroCheck, NGAL, proteinuria, albuminuria, acantocytes at urinary sediment) predictors of AKI that might efficiently predict long-term GFR decline after robotic Nephron-Spearing Surgery (rNSS). Methods: Monocentric prospective observational study. Patients scheduled for rNSS for suspected localized Renal Cell Carcinoma from May 2017 to October 2017 were enrolled. Samples were collected preoperatively and postoperatively (timepoints: 4 h, 10 h, 24 h, 48 h), while kidney function was re-assessed up to 24 months. Results: 38 patients were included; 16 (42%) developed clinical AKI. The eGFR decline at 24 months was more pronounced after postoperative AKI (−20.75 vs. −7.20, p < 0.0001). KineticGFR at 4 h (p = 0.008) and NephroCheck at 10 h (p = 0.001) were, at multivariable linear regression analysis, efficient predictors of post-operative AKI and long-term eGFR decline if compared to creatinine (R2 0.33 vs. 0.04). Conclusions: NephroCheck and kineticGFR have emerged as promising noninvasive, accurate, and early biomarkers of postoperative AKI and long-term GFR decline after rNSS. Combining NephroCheck and kineticGFR in clinical practice would allow to identify high risk of postoperative AKI and long-term GFR decline as early as 10 h after surgery.

Clinical Benefits of Indocyanine Green Fluorescence in Robot-Assisted Partial Nephrectomy

Background: To compare the intraoperative and postoperative outcomes of indocyanine green (ICG) administration in robot-assisted partial nephrectomy (RAPN) and report the differences in the results between patients with benign and malignant renal tumors. Methods: From 2017 to 2020, 132 patients underwent RAPN at our institution, including 21 patients with ICG administration. Clinical data obtained from our institution’s RAPN database were retrospectively reviewed. Intraoperative, postoperative, pathological, and functional outcomes of RAPN were assessed. Results: The pathological results indicated that among the 127 patients, 38 and 89 had received diagnoses of benign and malignant tumors, respectively. A longer operative time (311 vs. 271 min; p = 0.006) but superior preservation of estimated glomerular filtration rate (eGFR) at 3-month follow-up (90% vs. 85%; p = 0.031) were observed in the ICG-RAPN group. Less estimated blood loss, shorter warm ischemia time, and superior preservation of eGFR at postoperative day 1 and 6-month follow-up were also noted, despite no significant differences. Among the patients with malignant tumors, less estimated blood loss (30 vs. 100 mL; p < 0.001) was reported in the ICG-RAPN subgroup. Conclusions: Patients with ICG-RAPN exhibited superior short-term renal function outcomes compared with the standard RAPN group. Of the patients with malignant tumors, ICG-RAPN was associated with less blood loss than standard RAPN without a more positive margin rate. Further studies with larger cohorts and prospective designs are necessary to verify the intraoperative and functional advantages of the green dye.

On the black slope: analysis of the course of a blunt renal trauma collective in a winter sports region

Purpose

The aim of this study was to analyze the injury patterns and clinical course of a winter sport dominated by blunt renal trauma collective.

Methods

Blunt renal trauma cases (N = 106) treated in a Level 1 Trauma Center in Austria were analyzed.

Results

We encountered 12.3% grade 1, 10.4% grade 2, 32.1% grade 3, 38.7% grade 4 and 6.6% grade 5 renal traumata classified according to the American Association for the Surgery of Trauma (AAST). The mechanisms of injury (MOI) did not have an influence on the frequency of HG trauma (i.e., grade 4 and 5). No concomitant injuries (CIs) were found in 57.9% of patients. The number of patients without CIs was significantly higher in the sports associated trauma group compared to other MOIs (p < 0.01). In 94.3% the primary treatment was a non-operative management (NOM) including 56.6% conservative, 34.0% endourological, and 3.8% interventional therapies. A follow-up computed tomography (FU-CT) was performed in 81.1%, 3.3 days after trauma. After FU-CT, the primary therapy was changed in 11.4% of cases (grade ≥ 3). Comparing the Hb loss between the patients with grade 3 and 4 kidney trauma with and without revision surgery, we find a significantly increased Hb loss within the first 96 h after the trauma in the group with a needed change of therapy (p < 0.0001). The overall rate of nephrectomy (primary or secondary) was 9.4%. Independent predictors of nephrectomy were HG trauma (p < 0.01), age (p < 0.05), and sex (p < 0.05). The probability of nephrectomy was lower with (winter) sports-associated trauma (p < 0.1).

Conclusions

Sports-associated blunt renal trauma is more likely to occur isolated, and has a lower risk of severe outcomes, compared to other trauma mechanisms. NOM can successfully be performed in over 90% of all trauma grades.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01830-w.

Risk of Postoperative Renal Failure in Radical Nephrectomy and Nephroureterectomy: A Validated Risk Prediction Model

INTRODUCTION

The study aimed to construct and validate a risk prediction model for incidence of postoperative renal failure (PORF) following radical nephrectomy and nephroureterectomy.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database years 2005-2014 were used for the derivation cohort. A stepwise multivariate logistic regression analysis was conducted, and the final model was validated with an independent cohort from the ACS-NSQIP database years 2015-2017.

RESULTS

In cohort of 14,519 patients, 296 (2.0%) developed PORF. The final 9-factor model included age, gender, diabetes, hypertension, BMI, preoperative creatinine, hematocrit, platelet count, and surgical approach. Model receiver-operator curve analysis provided a C-statistic of 0.79 (0.77, 0.82; p < 0.001), and overall calibration testing R2 was 0.99. Model performance in the validation cohort provided a C-statistic of 0.79 (0.76, 0.81; p < 0.001).

CONCLUSION

PORF is a known risk factor for chronic kidney disease and cardiovascular morbidity, and is a common occurrence after unilateral kidney removal. The authors propose a robust and validated risk prediction model to aid in identification of high-risk patients and optimization of perioperative care.

Impact of comorbidities on acute kidney injury and renal function impairment after partial and radical tumor nephrectomy

BACKGROUND

To test for the impact of patient comorbidities and medical risk factors on kidney function after partial (PN) or radical nephrectomy (RN) in renal cell carcinoma (RCC) patients with normal preoperative renal function.

MATERIALS AND METHODS

From January 2011 to December 2014, 195 consecutive RCC patients with a preoperative estimated glomerular filtration rate (eGFR) > 60 ml/min/1.73 m² underwent PN or RN. Stratification was performed according to postoperative acute kidney injury (AKI) vs. no AKI. Moreover, logistic regression models tested for risk factors predicting postoperative AKI and subsequent new-onset chronic kidney disease (eGFR < 60 or < 45 ml/min/1.73 m²).

RESULTS

Of all eligible patients, 127 (65.1%) exhibited AKI. AKI patients underwent more frequently RN (44.9 vs. 13.2% PN) and harbored more often preoperative diabetes (17.3 vs. 5.9% no diabetes), hypertension (46.5 vs. 23.5% no hypertension) and larger median tumor size (4.5 vs. 2.5 cm, all p < 0.05) than non-AKI patients. Moreover, after median follow-up of 14 months, 18.9% of AKI patients exhibited an eGFR < 60 ml/min/1.73 m² vs. 7.4% non-AKI patients (p = 0.01). In multivariable models, hypertension and RN were risk factors for postoperative AKI (both p < 0.01). Age > 60 years and RN as well as preoperative diabetes were risk factors for postoperative eGFR < 60 or < 45 ml/min/1.73 m² (all p < 0.05), respectively.

CONCLUSIONS

Postoperative AKI is a non-negligible event especially after RN that can be further triggered by comorbidities such as diabetes and hypertension. Comorbidities should be considered in clinical decision-making for RCC surgery and patients need to be counseled about the increased risk of consecutive renal function impairment.

More than ancillary records: clinical implications of renal pathology examination in tumor nephrectomy specimens

Background

Nephrectomy is the management of choice for the treatment of renal tumors. Surgical pathologists primarily focus on tumor diagnosis and investigations relating to prognosis or therapy. Pathological changes in non-neoplastic tissue may, however, be relevant for further management and should be thoroughly assessed.

Methods

Here, we examined the non-neoplastic renal parenchyma in 206 tumor nephrectomy specimens for the presence of glomerular, tubulo-interstitial, or vascular lesions, and correlated them with clinical parameters and outcome of renal function.

Results

We analyzed 188 malignant and 18 benign or pseudo-tumorous lesions. The most common tumor type was clear cell renal cell carcinoma (CCRCC, n = 106) followed by papillary or urothelial carcinomas (n = 25). Renal pathology examination revealed the presence of kidney disease in 39 cases (18.9%). Glomerulonephritis was found in 15 cases (7.3%), and the most frequent was IgA nephropathy (n = 6; 2.9%). Vasculitis was found in two cases (0.9%). In 15 cases we found tubulo-interstitial nephritis, and in 9 severe diabetic or hypertensive nephropathy. Partial nephrectomy was not linked to better eGFR at follow-up. Age, vascular nephropathy, glomerular scarring and interstitial fibrosis were the leading independent negative factors influencing eGFR at time of surgery, whereas proteinuria was associated with reduced eGFR at 1 year.

Conclusion

Our large study population indicates a high incidence of renal diseases potentially relevant for the postoperative management of patients with renal neoplasia. Consistent and systematic reporting of non-neoplastic renal pathology in tumor nephrectomy specimens should therefore be mandatory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40620-021-01030-0.

Concomitant Drug Treatment and Elimination in the RCC-affected Kidneys: Can We Kill Two Birds with One Stone?

BACKGROUND

The kidneys are vital organs acting as the body's filters that eliminate drugs and other waste products from the body. For effective cancer therapy, a delicate balance is required in the drug treatment and its elimination, which is critical for drug accumulation, toxicity, and kidney malfunction. However, how renal cell carcinoma (RCC) affects the kidneys in safely eliminating the byproducts of drug treatments in patients with severely dysregulated kidney functions had remained elusive. Recent advancements in dose adjustment have added to our understanding regarding how drug treatments could be effectively regulated in aberrant kidney cells, driving safe elimination and reducing drug accumulation and toxicity at the right time and space. Dose adjustment is the only standard systemic way applicable; however, it presents certain limitations. There is significant room for developing new strategies and alternatives to improve it.

OBJECTIVES

Our analysis of the available treatments in literature discusses the treatment and their safe eliminations. In this study, we give an overview of the measures that could be taken to maintain the elimination gradient of anti-cancer drugs and restore normal kidney function in RCC. Differential therapeutics of RCC/mRCC in various clinical phase trials and the interaction of targeted therapeutics in response to vascular endothelial growth factor (VEGF) were also discussed.

CONCLUSION

Such information might suggest a new direction in controlling treatment with safe elimination through dose adjustment and its associated alternatives in a judicious manner. A strategy to systematically focus on the safe elimination of anti-cancer drugs in RCC strongly needs advocating.

KDIGO Controversies Conference on onco-nephrology: understanding kidney impairment and solid-organ malignancies, and managing kidney cancer

The association between kidney disease and cancer is multifaceted and complex. Persons with chronic kidney disease (CKD) have an increased incidence of cancer, and both cancer and cancer treatments can cause impaired kidney function. Renal issues in the setting of malignancy can worsen patient outcomes and diminish the adequacy of anticancer treatments. In addition, the oncology treatment landscape is changing rapidly, and data on tolerability of novel therapies in patients with CKD are often lacking. Caring for oncology patients has become more specialized and interdisciplinary, currently requiring collaboration among specialists in nephrology, medical oncology, critical care, clinical pharmacology/pharmacy, and palliative care, in addition to surgeons and urologists. To identify key management issues in nephrology relevant to patients with malignancy, KDIGO (Kidney Disease: Improving Global Outcomes) assembled a global panel of multidisciplinary clinical and scientific expertise for a controversies conference on onco-nephrology in December 2018. This report covers issues related to kidney impairment and solid organ malignancies as well as management and treatment of kidney cancer. Knowledge gaps, areas of controversy, and research priorities are described.

Perspectives From an Onconephrology Interest Group: Conference Report

INTRODUCTION AND OBJECTIVE

Onconephrology is a new and evolving field that deals with kidney complications in patients with cancer as well as the management of cancer in patients with preexisting kidney disease. With increasing numbers of patients with cancer with kidney-related complications, the field has garnered increased attention. Thus, an annual Greater Toronto Area Onconephrology Interest Group symposium was held in May 2019. The objective of the meeting was to demonstrate the junctures between oncology and nephrology by highlighting recent data regarding (1) kidney impairment in solid organ malignancies, (2) management and treatment of kidney cancer, (3) kidney impairment in hematologic malignancies, (4) malignancy and kidney transplantation, and (5) hyponatremia in patients with cancer.

METHODS AND SOURCES OF INFORMATION

Through a structured presentation, the group explored key topics discussed at a Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference on Onconephrology. Expert opinions, clinical trial findings, and publication summaries were used to illustrate patient and treatment-related considerations in onconephrology.

KEY FINDINGS

Kidney complications in patients with cancer are a central theme in onconephrology. An estimated 12% to 25% of patients with solid organ malignancies have chronic kidney disease (CKD), although in certain cancers, the prevalence of CKD is higher. Kidney impairment is also a common complication of some hematologic malignancies. The incidence of renal failure in patients with multiple myeloma is estimated at 18% to 56% and light chain cast nephropathy is seen in approximately 30% of these patients. In addition, there appears to be a bidirectional relationship between kidney cancer and CKD, with some data sets suggesting the risk increases as kidney function declines. Cancer is also of concern in patients with preexisting kidney disease. Kidney transplant recipients have a greater risk of cancer and a higher risk of cancer-related mortality. Kidney complications have also been associated with novel cancer therapies, such as immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy. An estimated 2% to 4% of patients initiating an immune checkpoint inhibitor may develop nephrotoxicity, whereas up to 40% of patients on CAR T-cell therapy experience cytokine release syndrome (CRS). Tumor lysis syndrome and electrolyte abnormalities, such as hyponatremia, have also been reported with CAR T-cell therapy. While the incidence and prevalence of hyponatremia vary depending on the cancer type and serum sodium cutoff point, hyponatremia may be seen in up to 46% of patients hospitalized in cancer centers.

CONCLUSIONS

Onconephrology is a developing field and the themes arising from this meeting indicate a need for greater collaboration between oncologists and nephrologists. Educational symposia and onconephrology fellowship programs may allow for improved cancer care for patients with kidney disease.

Renal functional reserve: from physiological phenomenon to clinical biomarker and beyond

Glomerular filtration rate (GFR) is acutely increased following a high-protein meal or systemic infusion of amino acids. The mechanisms underlying this renal functional response remain to be fully elucidated. Nevertheless, they appear to culminate in preglomerular vasodilation. Inhibition of the tubuloglomerular feedback signal appears critical. However, nitric oxide, vasodilator prostaglandins, and glucagon also appear important. The increase in GFR during amino acid infusion reveals a "renal reserve," which can be utilized when the physiological demand for single nephron GFR increases. This has led to the concept that in subclinical renal disease, before basal GFR begins to reduce, renal functional reserve can be recruited in a manner that preserves renal function. The extension of this concept is that once a decline in basal GFR can be detected, renal disease is already well progressed. This concept likely applies both in the contexts of chronic kidney disease and acute kidney injury. Critically, its corollary is that deficits in renal functional reserve have the potential to provide early detection of renal dysfunction before basal GFR is reduced. There is growing evidence that the renal response to infusion of amino acids can be used to identify patients at risk of developing either chronic kidney disease or acute kidney injury and as a treatment target for acute kidney injury. However, large multicenter clinical trials are required to test these propositions. A renewed effort to understand the renal physiology underlying the response to amino acid infusion is also warranted.

Achieving the "trifecta" with open versus minimally invasive partial nephrectomy

INTRODUCTION

The "trifecta" is a summary measure of outcome after partial nephrectomy (PN) that encompasses three parameters: negative surgical margin, ≤ 10% decrease in post-operative estimated glomerular filtration rate (eGFR) and absence of urological complications. We assessed trifecta rates in patients undergoing open (OPN), laparoscopic (LPN), and robotic PN (RPN) for a clinical T1 renal mass (≤ 7 cm).

METHODS

Clinical and pathologic parameters were extracted from the prospectively maintained Canadian Kidney Cancer Information System for patients treated between January 2011 and October 2018. Comparisons between groups were made using Kruskal-Wallis test for continuous variables and Chi-squared independence test for categorical variables. Multivariable analysis was performed to identify predictors of each component of the trifecta and the trifecta itself.

RESULTS

Of 1708 total patients, 746 underwent OPN, 678 LPN, and 284 RPN for a T1 renal mass. A 'trifecta' was achieved in 53% OPN, 52% LPN and 47% RPN (p = 0.194). On multivariable analysis, OPN and LPN were associated with less frequent post-operative decline in eGFR and more frequent trifecta when compared to RPN, but there was no difference between OPN and LPN. OPN also predicted a higher rate of negative margins compared to RPN but not LPN.

CONCLUSION

After correction for confounding variables, OPN and LPN were more likely than RPN to achieve the trifecta, which appeared to be due primarily to loss of renal function. No difference was observed between OPN and LPN. Analyses were limited by the lack of nephrometry score.

Effect of everolimus on renal function in patients with tuberous sclerosis complex: evidence from EXIST-1 and EXIST-2

Background

A reduction in renal angiomyolipoma volume observed with everolimus (EVE) treatment in patients with tuberous sclerosis complex (TSC) has been postulated to translate to clinical benefit by reducing the risk of renal hemorrhage and chronic renal failure.

Methods

The long-term effects of EVE on renal function (∼4 years of treatment) were examined in patients treated with EVE in the Phase 3 EXIST-1 and EXIST-2 studies. Patients in EXIST-1 had TSC and subependymal giant cell astrocytoma (SEGA), and patients in EXIST-2 had renal angiomyolipoma and a definite diagnosis of TSC or sporadic lymphangioleiomyomatosis. EVE was administered at 4.5 mg/m²/day, with adjustment to achieve target trough levels of 5–15 ng/mL in EXIST-1 and at 10 mg/day in EXIST-2. Estimated glomerular filtration rate (eGFR) and creatinine levels were assessed at baseline, at Weeks 2, 4, 6, 8, 12 and 18, then every 3 months thereafter. Proteinuria was graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.

Results

A total of 111 patients from EXIST-1 and 112 patients from EXIST-2 were included in this analysis. Respective mean ages at EVE initiation were 10.5 [standard deviation (SD) 6.45] and 33.2 (SD 10.29) years, and 3.6% and 37.5% of patients had undergone prior renal intervention. Mean baseline eGFR was 115 and 88 mL/min/1.73 m² in EXIST-1 and EXIST-2, respectively. Overall, mean eGFR remained stable over time in both studies, with an decline in renal function mostly confined to some patients with severely compromised renal function before treatment. Patients with prior renal intervention exhibited low eGFR values throughout the study. The incidence of proteinuria increased after initiating treatment with EVE and was mostly Grade 1/2 in severity, with Grade 3 proteinuria reported in only two patients. Measurements of proteinuria were limited by the use of urine dipstick tests.

Conclusions

The use of EVE does not appear to be nephrotoxic in patients with SEGA or renal angiomyolipoma associated with TSC and may preserve renal function in most patients.

ClinicalTrials.gov identifiers NCT00789828 and NCT00790400

CT Angiography Findings Predictive of Kidney Injury in Chronic Aortic Dissection

OBJECTIVE. The purpose of this study was to compare the volume alteration and effective renal plasma flow of kidneys supplied by false lumens (FLs) with those of kidneys supplied by true lumens (TLs), to show the discrepancy in perfusion between the two lumens. We sought to corroborate malperfusion of FL-supplied kidneys with imaging characteristics observed on CT angiography. MATERIALS AND METHODS. A retrospective analysis was conducted using prospectively collected data for 87 patients with a diagnosis of residual chronic aortic dissection between 2005 and 2013 who had one kidney perfused by a TL and the other kidney perfused by a FL. RESULTS. Overall, at follow-up, FL-supplied kidneys had a mean (± SD) effective renal plasma flow (117.5 ± 42.6 vs 146.6 ± 41.0 mL/min; p = 0.004) and volume (131.1 ± 37.1 vs 146.5 ± 33.3 cm³; p = 0.004) that were lower than those of TL-supplied kidneys. Multivariate analysis revealed the presence of a proximal major inlet (odds ratio, 0.306; 95% CI, 0.103-0.910; p = 0.033) and large FL area (odds ratio, 0.104; CI, 0.012-0.880; p = 0.038) as factors protecting against malperfusion of FL-supplied kidneys. In patients with dissected renal arteries, the FL-supplied kidney had low effective renal plasma flow (mean, 88.5 ± 26.8 vs 149.6 ± 43.5 mL/min; p = 0.004) and diminished volume (mean, 120.4 ± 30.4 vs 152.3 ± 24.6 cm³; p = 0.001). CONCLUSION. In the present study, kidneys perfused by FLs showed decreased volume and reduced effective renal plasma flow during follow-up, particularly those kidneys with dissected renal arteries, a small FL area at the renal level, and lack of a proximal major inlet. Further studies are warranted to identify the clinical relevance of malperfusion in FL-supplied kidneys.

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.

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.

Renal tumor structured reporting including nephrometry score and beyond: what the urologist and interventional radiologist need to know

The purpose of this paper is to describe cross-sectional imaging anatomic and morphologic parameters of solid renal tumors that urologists and interventional radiologists need for precise management, review the commonly used terms and descriptors of those parameters, and suggest a comprehensive reporting system for detected masses.

A multi-institutional report of peri-operative and functional outcomes after robot-assisted partial nephrectomy in patients with a solitary kidney

To evaluate peri- and post-operative outcomes after robotic partial nephrectomy (RPN) in patients with a solitary kidney. A multi-institutional database of 1868 patients was used to identify 35 patients with a solitary kidney who underwent RPN at six different centers from 2007 to 2016. Peri-operative outcomes were summarized with descriptive statistics. We assessed the change in eGFR over time with a linear mixed-effects model. Median operative time, ischemia time, and estimated blood loss were 172 min, 16 min, and 113 mL, respectively. There were no positive surgical margins. The median length of stay was 1 day (range 1-7), and over half (54.3%) of patients were discharged one post-operative day 1. Seven post-operative complications occurred in six patients (17.1%); of which four were Clavien I, two were Clavien II, and one was Clavien III. The linear decline in eGFR up to 24 month post-RPN was marginal and not significant (ß = - 0.14; 95% CI = - 0.51, 0.23; p = 0.453), with predicted mean eGFR decreasing from 59.2 to 55.8 mL/min/1.73 m² at 24 months. These results suggest that, in patients with a solitary kidney, RPN is a safe and feasible treatment option. In patients with a solitary kidney, RPN did not significantly compromise renal function for up to 2 years after surgery.

Disease progression and kidney function after partial vs. radical nephrectomy for T1 renal cancer

PURPOSE

Partial nephrectomy (PN) for early stage renal cancer preserves renal function better than radical nephrectomy (RN) and is generally considered oncologically similar. The Intergroup European Organisation for Research and Treatment of Cancer trial comparing outcomes after PN vs. RN, however, showed reduced overall survival in the PN group. Our aim was to evaluate recurrence, death, and renal function after PN vs. RN for T1 tumors in a Canadian population.

MATERIALS AND METHODS

From 2000 to 2015, 2,358 patients with a first occurrence of a clinical T1 renal cancer who underwent PN or RN were identified from the Canadian Kidney Cancer Information System. Clinical, surgical, and pathologic parameters were analyzed. Time to progression was compared after PN vs. RN using a Cox proportional hazards model, adjusted for pertinent variables.

RESULTS

Inclusion criteria were met in 1,615 PN and 743 RN. Preoperative characteristics appeared similar in both groups. Time to progression was not different after PN vs. RN, adjusted for potential confounders (hazard ratio = 1.17 [95% CI: 0.8-1.72, P = 0.42]). Postoperative estimated glomerular filtration rate at 1 and 3 years was significantly greater for PN vs. RN in a linear regression model, accounting for preoperative estimated glomerular filtration rate.

CONCLUSIONS

These results suggest that progression-free survival after PN and RN in patients with T1 renal cancer was similar, but that there was better preservation of renal function after PN. This suggests that both PN and RN have similar oncological efficiency, and that selection of surgical approach should be based on other factors such as technical feasibility, potential complications, and preservation of renal function.

Renal Damage Frequency in Patients with Solitary Kidney and Factors That Affect Progression

Background. The aim of this study is to assess renal damage incidence in patients with solitary kidney and to detect factors associated with progression. Methods. Medical records of 75 patients with solitary kidney were investigated retrospectively and divided into two groups: unilateral nephrectomy (group 1) and unilateral renal agenesis/dysplasia (group 2). According to the presence of kidney damage, each group was divided into two subgroups: group 1a/b and group 2a/b. Results. Patients in group 1 were older than those in group 2 (p = 0.001). 34 patients who comprise group 1a had smaller kidney size (p = 0.002) and higher uric acid levels (p = 0.028) than those in group 1b at presentation. Uric acid levels at first and last visit were associated with renal damage progression (p = 0.004, 0.019). 18 patients who comprise group 2a were compared with those in group 2b in terms of presence of DM (p = 0.038), HT (p = 0.003), baseline proteinuria (p = 0.014), and uric acid (p = 0.032) levels and group 2a showed higher rates for each. Progression was more common in patients with DM (p = 0.039), HT (p = 0.003), higher initial and final visit proteinuria (p = 0.014, for both), and higher baseline uric acid levels (p = 0.047). Conclusions. The majority of patients with solitary kidney showed renal damage at presentation. Increased uric acid level is a risk factor for renal damage and progression. For early diagnosis of renal damage and reducing the risk of progression, patients should be referred to a nephrologist as early as possible.

Non-neoplastic Pathology in Tumor Nephrectomy Specimens

Risk factors for kidney cancers and medical kidney diseases are similar; therefore, it is not surprising that up to 25% of renal cell carcinoma patients have chronic kidney disease prior to nephrectomy and a significant number of patients with normal prenephrectomy renal function markers progress to chronic kidney disease over time. Evaluation of non-neoplastic parenchyma in tumor nephrectomy specimens can identify patients at risk for progression to chronic kidney disease, which is a critical step for early intervention and potential improvement of morbidity and mortality rates in this patient population.

Can selective arterial clamping with fluorescence imaging preserve kidney function during robotic partial nephrectomy?

OBJECTIVE

To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging.

METHODS

From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was used in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative estimated glomerular filtration rate (eGFR), functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging.

RESULTS

In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5 mL/min/1.73 m(2); P = .04), absolute reduction of eGFR (-2.5 vs -14.0 mL/min/1.73 m(2); P <.01), and percent change in eGFR (-1.9% vs -16.8%; P <.01). Similar trends were noted at 3 month follow-up, but these differences became nonsignificant (P[eGFR] = .07; P[absolute reduction of eGFR] = .10; and P[percent change in eGFR] = .07). In the selective clamping group, a total of 4 perioperative complications occurred in 3 patients, all of which were Clavien grade I-III.

CONCLUSION

Use of NIRF imaging was associated with improved short-term renal functional outcomes when compared with RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment of kidney-specific functional outcomes are needed to further assess the benefits of this technology.

Renal histologic parameters influencing postoperative renal function in renal cell carcinoma patients

BACKGROUND

Pre-existing non-neoplastic renal diseases or lesions may influence patient renal function after tumor removal. However, its description is often neglected or omitted in pathologic reports. To determine the incidence and clinical significance of non-neoplastic lesions, we retrospectively examined renal tissues obtained during 85 radical nephrectomies for renal cell carcinoma.

METHODS

One paraffin-embedded tissue block from each case containing a sufficient amount of non-tumorous renal parenchyma was cut and processed with hematoxylin and eosin and periodic acid-Schiff methods. Non-neoplastic lesions of each histological compartment were semi-quantitatively and quantitatively evaluated.

RESULTS

Among the various histologic lesions found, tubular atrophy, arterial intimal thickening, and glomerulosclerosis were the most common (94.1%, 91.8%, and 88.2%, respectively). Glomerulosclerosis correlated with estimated glomerular filtration rate at the time of surgery, as well as at 1- and 5-years post-surgery (p=.0071), but tubulointerstitial fibrosis or arterial fibrous intimal thickening did not. Post-hoc analysis revealed that glomerulosclerosis of more than 20% predicted post-operative renal function. However, its significance disappeared when gender and age were considered.

CONCLUSIONS

In conclusion, non-neoplastic lesions, especially with regard to glomerulosclerosis percentage, should be described in pathology reports to provide additional information on renal function decline.

Effect of total and partial nephrectomy on the elimination of ciprofloxacin in humans

BACKGROUND

Renal cell carcinoma (RCC) is the most common form of kidney cancer. Surgery is a standard procedure to resect the tumor during total (TN) or partial (nephron-sparing) nephrectomy (PN). Ciprofloxacin is most often administered at the usual intravenous dose of 100-400 mg/12 h. The application of such low doses of ciprofloxacin as 200 mg/24 h carries the risk of achieving subtherapeutic concentrations even in patients with limited renal function. The aim of the study was a comparison of concentrations and pharmacokinetics for ciprofloxacin at steady-state in patients after total and partial nephrectomy and evaluation of the effectiveness of the iv dose 200 mg/24 h against the theoretical value of MIC, 0.5 μg/ml.

METHODS

The research was carried out on two groups of patients after nephrectomy: total (group 1, n = 21; mean [SD], age, 62.9 [14.4] years; weight, 76.0 [14.6] kg; creatinine clearance, CL(CR), 90.7 [22.2] ml/min) and partial (group 2, n = 15; 61.7 [9.3] years; 87.8 [16.4] kg; CL(CR), 107.8 [36.4] ml/min). The patients were treated with ciprofloxacin in the dose of 200 mg/24 h (iv). Plasma concentrations of ciprofloxacin at steady state were measured with validated HPLC method with UV detection.

RESULTS

The mean values of plasma concentrations of ciprofloxacin at steady state in group 1 and 2 were: C(ss)(max), 2.012 and 1.345; C(ss)(min), 0.437 and 0.244 μg/ml, respectively. The main pharmacokinetic parameters for ciprofloxacin in group 1 and 2 were as follows: AUC((0-last)), 30.9 [17.9] and 19.5 [8.7] μg h/ml; AUMC((0-last)), 177.91 [11.1] and 91.9 [66.5] μg h(2)/ml; t(1/2β), 13.9 [7.7] and 9.8 [3.3] h; MRT, 16.5 [12.1] and 9.77 [5.4] h; V(d), 115.0 [67.2] and 142.2 [78.7] l; CL, 6.2 [3.3] and 10.8 [5.7] l/h, respectively. With the assumed MIC = 0.5 μg/ml, the values of C(ss)(max)/MIC < 10 and AUC/MIC < 125 were obtained in all the patients.

CONCLUSION

In our patients we observed significant differences in some pharmacokinetic parameters of ciprofloxacin after two types of nephrectomy.

Assessing renal function after partial nephrectomy using renal nuclear scintigraphy and estimated glomerular filtration rate

OBJECTIVE

To create a model intended to more accurately characterize renal function alteration after partial nephrectomy using a combination of renal scintigraphy and estimated glomerular filtration rate (eGFR).

METHODS

Thirty-two partial nephrectomy patients from a single center with preoperative and postoperative renal scans were reviewed. Renal scan data were used to calculate proportional eGFR in the involved kidney as a product of the percentage function of the operated kidney and total eGFR. Linear regression models were created to describe endpoints (postoperative eGFR, involved kidney percent function, proportional eGFR) as functions of clinical variables associated with kidney damage.

RESULTS

For the ipsilateral kidney, mean preoperative percent function and eGFR were 50% (SD, 4.8) and 31 mL/min/m(2) (SD, 3.4), respectively; postoperative percent function and involved kidney eGFR were 44% (SD, 9.0) and 27 mL/min/m(2) (SD, 9.0), respectively. Decreased postoperative proportional eGFR was significantly associated with increased clamp time and tumor size in univariate linear regression models. Clamp time was associated with total eGFR, where tumor size was not. Additionally, clamp time and tumor size explain more of the variation in proportional eGFR (R(2) = 0.39 and R(2) = 0.17, respectively), compared to percent effort and total eGFR.

CONCLUSION

Proportional eGFR has a stronger association with putative factors of renal dysfunction after partial nephrectomy, including clamp time and tumor size, compared to total eGFR, indicating it may be a more sensitive marker of renal function after partial nephrectomy.

Functional and oncologic outcomes of bilateral open partial nephrectomy versus bilateral laparoscopic partial nephrectomy

PURPOSE

This study compared operative data and outcomes in patients undergoing either bilateral open partial nephrectomy (BOPN) or bilateral laparoscopic partial nephrectomy (BLPN) for synchronous bilateral kidney tumors.

PATIENTS AND METHODS

Patients who had undergone bilateral partial nephrectomy at our institution between 1992 and 2008 were reviewed retrospectively; 114 patients underwent either BOPN or BLPN. Ischemia time, tumor size, and renal function outcomes immediately after each surgery, at an intermediate time point (≤12 months), and at a late time point (>12 months) were compared. Oncologic outcomes were also evaluated using Kaplan-Meier analysis.

RESULTS

BOPN and BLPN were conducted in 92 and 22 patients, respectively. Average tumor size was larger in the BOPN group (4.1 vs 2.7 cm; P=0.001); however, pathologic stage was equivalent (P=0.52). Hospital stay was longer in the BOPN group (5.6 vs 4.0 d; P<0.001). Preoperative estimated glomerular filtration rates (eGFR) in the BOPN and BLPN groups were both ≥60 mL/min/1.73 m(2). Percent decrease in eGFR between the two groups was 38% in the BLPN group and 27% in the BOPN group (P=0.03). Cancer-specific and recurrence-free survival rates were equivalent between groups over a mean follow-up of 5.5 years.

CONCLUSIONS

BOPN and BLPN resulted in equivalent intermediate-term oncologic control. BLPN was associated with a larger percent decrease in eGFR. As ischemia times shorten for contemporary laparoscopic partial nephrectomies, it is expected that functional outcomes will be equivalent.