Chronic Kidney Disease After Partial Nephrectomy in Patients With Preoperative Inconspicuous Renal Function - Curiosity or Relevant Issue?

Impact of a kidney-adjusted ERAS® protocol on postoperative outcomes in patients undergoing partial nephrectomy

PURPOSE

Evaluation of a kidney-adjusted enhanced recovery after surgery (ERAS®) protocol (kERAS) in patients undergoing nephron-sparing surgery (PN).

METHODS

The kERAS protocol is a multidimensional protocol focusing on optimized perioperative fluid and nutrition management as well as strict intraoperative and postoperative blood pressure limits. It was applied in a prospective cohort (n = 147) of patients undergoing open or robotic PN. Patients were analyzed for the development of acute postoperative renal failure (AKI), achievement of TRIFECTA criteria, upstaging or new onset of chronic kidney disease (CKD) and length of hospital stay (LOS) and compared to a retrospective cohort (n = 162) without application of the protocol.

RESULTS

Cox regression analyses could not confirm a protective effect of kERAS on the development of AKI post-surgery. A positive effect was observed on TRIFECTA achievement (OR 2.2, 95% CI 1.0-4.5, p = 0.0374). Patients treated with the kERAS protocol showed less long-term CKD upstaging compared to those treated with the standard protocol (p = 0.0033). There was no significant effect on LOS and new onset of CKD.

CONCLUSION

The implementation of a kERAS protocol can have a positive influence on long-term renal function in patients undergoing PN. It can be used safely without promoting AKI. Furthermore, it can be realized with a manageable amount of additional effort.

Impact of chronic kidney disease stages on surgical and functional outcomes in robot-assisted partial nephrectomy for localized renal tumors

The influence of chronic kidney disease stage on robot-assisted partial nephrectomy outcomes remains underexplored. This study aimed to assess the impact of chronic kidney disease stage on functional and surgical outcomes of robot-assisted partial nephrectomy and identify preoperative predictors of significant postoperative 1-year renal-function loss (RFL). Clinical data of 408 patients who underwent robot-assisted partial nephrectomy at Yokohama City University Hospital between 2016 and 2023 were retrospectively reviewed. The da Vinci Surgical System was applied in all patients, and outcomes assessed included surgical parameters, postoperative estimated glomerular filtration rate, trifecta and pentafecta achievements, and complications. Significant RFL was defined as estimated glomerular filtration rate reduction ≥ 25% from baseline. Higher chronic kidney disease stages correlated with older age, hypertension, diabetes, and solitary kidneys. Postoperative estimated glomerular filtration rate decline was most pronounced in patients with chronic kidney disease stages 4-5. Although the chronic kidney disease stage did not significantly affect most surgical parameters, pentafecta achievement was higher in patients with chronic kidney disease stage 3 than in those with stages 4-5. Two patients required hemodialysis after robot-assisted partial nephrectomy. Multivariable logistic regression analysis showed that preoperative hemoglobin level and maximum tumor diameter were significant predictive factors for significant RFL. In conclusion, preoperative CKD stage did not influence on surgical outcome except for pentafecta achievement. RAPN may be feasible for patients with CKD stages 4-5 because of no rapid progression to hemodialysis induction and no procedure-related mortality. Preoperative hemoglobin levels and tumor diameter emerged as predictors of significant RFL.

Development and internal validation of a nomogram predicting 3-year chronic kidney disease upstaging following robot-assisted partial nephrectomy

PURPOSE

Aim of the present study was to develop and validate a nomogram to accurately predict the risk of chronic kidney disease (CKD) upstaging at 3 years in patients undergoing robot-assisted partial nephrectomy (RAPN).

METHODS

A multi-institutional database was queried to identify patients treated with RAPN for localized renal tumor (cT1-cT2, cN0, cM0). Significant CKD upstaging (sCKD-upstaging) was defined as development of newly onset CKD stage 3a, 3b, and 4/5. Model accuracy was calculated according to Harrell C-index. Subsequently, internal validation using bootstrapping and calibration was performed. Then nomogram was depicted to graphically calculate the 3-year sCKD-upstaging risk. Finally, regression tree analysis identified potential cut-offs in nomogram-derived probability. Based on this cut-off, four risk classes were derived with Kaplan-Meier analysis tested this classification.

RESULTS

Overall, 965 patients were identified. At Kaplan-Meier analysis, 3-year sCKD-upstaging rate was 21.4%. The model included baseline (estimated glomerular filtration rate) eGFR, solitary kidney status, multiple lesions, R.E.N.A.L. nephrometry score, clamping technique, and postoperative acute kidney injury (AKI). The model accurately predicted 3-year sCKD-upstaging (C-index 84%). Based on identified nomogram cut-offs (7 vs 16 vs 26%), a statistically significant increase in sCKD-upstaging rates between low vs intermediate favorable vs intermediate unfavorable vs high-risk patients (1.3 vs 9.2 vs 22 vs 54.2%, respectively, p < 0.001) was observed.

CONCLUSION

Herein we introduce a novel nomogram that can accurately predict the risk of sCKD-upstaging at 3 years. Based on this nomogram, it is possible to identify four risk categories. If externally validated, this nomogram may represent a useful tool to improve patient counseling and management.

An m6A-Driven Prognostic Marker Panel for Renal Cell Carcinoma Based on the First Transcriptome-Wide m6A-seq

To date, only a single transcriptome-wide m6A sequencing study of clear cell renal cell carcinoma (ccRCC) has been reported, with no validation so far. Herein, by TCGA analysis of the KIRC cohort (n = 530 ccRCC; n = 72 normal), an external expression validation of 35 preidentified m6A targets was performed. Further in-depth expression stratification enabled assessment of m6A-driven key targets. Overall survival (OS) analysis and gene set enrichment analyses (GSEA) were conducted to assess their clinical and functional impact on ccRCC. In the hyper-up cluster significant upregulation was confirmed for NDUFA4L2, NXPH4, SAA1, and PLOD2 (40%) and in the hypo-up cluster for FCHSD1 (10%). Significant downregulation was observed for UMOD, ANK3, and CNTFR (27.3%) in the hypo-down cluster and for CHDH (25%) in the hyper-down cluster. In-depth expression stratification showed consistent dysregulation in ccRCC only for 11.67%: NDUFA4L2, NXPH4, and UMOD (NNU-panel). Patients with strong NNU panel dysregulation had significantly poorer OS (p = 0.0075). GSEA identified 13 associated and significantly upregulated gene sets (all p-values < 0.5; FDR < 0.25). External validation of the only available m6A sequencing in ccRCC consistently reduced dysregulated m6A-driven targets on the NNU panel with highly significant effects on OS. Epitranscriptomics are a promising target for developing novel therapies and for identifying prognostic markers for daily clinical practice.

Predicting short- and long-term renal function following partial and radical nephrectomy

OBJECTIVES

To externally validate the previously published Mayo clinic model for the prediction of early (<30 days) postoperative renal failure, which relies solely on preoperative estimated glomerular filtration rate (eGFR) and develop a novel model for the prediction of long-term (>30 days) renal function after partial nephrectomy (PN) and radical nephrectomy (RN), including patient factors and nephrometry scores.

PATIENTS AND METHODS

Retrospective, single-center cohort study on patients who underwent PN or RN for a unilateral renal tumor between 2003 and 2019 with a preoperative eGFR of at least 15 ml/min/1.73m². Early postoperative renal failure was defined as eGFR <15 ml/min/1.73 m² or receipt of dialysis within 30 days. We determined the area under the receiver operating characteristics curve (AUC) to assess the Mayo clinic model's discriminative power. We used hierarchical linear mixed models with backward selection of candidate variables to develop a prediction model for long-term eGFR following PN and RN, separately. Their predictive ability was quantified using the marginal and conditional R²_GLMM and an internal validation.

RESULTS

We included 421 patients (7,548 eGFR observations) who underwent PN and 271 patients (6,530 eGFR observations) who underwent RN. The Mayo clinic model for prediction of early postoperative renal failure following PN and RN showed an AUC of 0.816 (95% CI 0.718-0.920) and 0.825 (95% CI 0.688-0.962), respectively. In multivariable models, long-term eGFR following PN was associated with age, diabetes, the presence of a solitary kidney, tumor diameter and preoperative eGFR, while long-term eGFR following RN was associated with age, body mass index, RENAL nephrometry score and preoperative eGFR. Marginal and conditional R²_GLMM were 0.591 and 0.855 for the PN model, and 0.363 and 0.849 for the RN model, respectively.

CONCLUSIONS

The Mayo clinic model for short-term renal failure prediction showed good accuracy on external validation. Our long-term eGFR prediction models depend mostly on host factors as opposed to tumor complexity and can aid in decision-making when considering PN vs. RN.

Estimating Postoperative Renal Function After Surgery for Nonmetastatic Renal Masses: A Systematic Review of Available Prediction Models

CONTEXT

A variety of models predicting postoperative renal function following surgery for nonmetastatic renal tumors have been reported, but their validity and clinical usefulness have not been formally assessed.

OBJECTIVE

To summarize prediction models available for estimation of mid- to long-term (>3 mo) postoperative renal function after partial nephrectomy (PN) or radical nephrectomy (RN) for nonmetastatic renal masses that include only preoperative or modifiable intraoperative variables.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was conducted using the MEDLINE, Embase, and Web of Science databases from January 2000 to March 2022 according to the PRISMA guidelines (PROSPERO ID: CRD42022303492). Risk of bias was assessed according to the Prediction Model Study Risk of Bias Assessment Tool.

EVIDENCE SYNTHESIS

Overall, 21 prediction models from 18 studies were included (nine for PN only; eight for RN only; four for PN or RN). Most studies relied on retrospective patient cohorts and had a high risk of bias and high concern regarding the overall applicability of the proposed model. Patient-, kidney-, surgery-, tumor-, and provider-related factors were included among the predictors in 95%, 86%, 100%, 61%, and 0% of the models, respectively. All but one model included both patient age and preoperative renal function, while only a few took into account patient gender, race, comorbidities, tumor size/complexity, and surgical approach. There was significant heterogeneity in both the model building strategy and the performance metrics reported. Five studies reported external validation of six models, while three assessed their clinical usefulness using decision curve analysis.

CONCLUSIONS

Several models are available for predicting postoperative renal function after kidney cancer surgery. Most of these are not ready for routine clinical practice, while a few have been externally validated and might be of value for patients and clinicians.

PATIENT SUMMARY

We reviewed the tools available for predicting kidney function after partial or total surgical removal of a kidney for nonmetastatic cancer. Most of the models include patient and kidney characteristics such as age, comorbidities, and preoperative kidney function, and a few also include tumor characteristics and intraoperative variables. Some models have been validated by additional research groups and appear promising for improving counseling for patients with nonmetastatic cancer who are candidates for surgery.

Risk Factors of Chronic Kidney Disease after Partial Nephrectomy

Background: In comparison with radical nephrectomy, partial nephrectomy (PN) is considered a better option for small renal mass surgery, because of optimal kidney tissue removal and parenchyma preservation. But there are patients with worsening postoperative renal function (RF) and chronic kidney disease (CKD) after PN. Therefore, the study aimed to evaluate and detect risk factors for CKD after PN.Materials and Methods. A prospective observational study was conducted, which consisted of 91 individuals who received PN with warm ischemia and an estimated preoperative glomerular filtration rate (eGFR) ≥ 60 ml/min/1.72m2 without pathologic albuminuria. Preoperative and intraoperative factors like intraoperative hypotension (IOH), blood loss, and resected part volume were analyzed.Results. At 6-month follow-up, 14 (15.4 %) patients experienced postoperative CKD. After 12 months of follow-up, 15 (16.5 %) patients had CKD. Patients with CKD had a lower preoperative eGFR than non-CKD group (69.0 vs 91.0 ml/min/1.72m2, p < 0.001), longer ischemia (20.0 vs 14.0, p = 0.002) and IOH time (40.0 (40.0; 47.5) vs 0.0 (0.0; 26.2) min, p < 0.001). Also, higher volumes of resected kidney part tumor and removed parenchyma with higher glomerulosclerosis amounts (73.3 % vs 14.5 %, p = 0.009) were found in CKD group. Estimated blood loss > 500 ml during PN was discovered to be the major risk factor for CKD development (OR 11.13, 95 % CI 1.88–65.92, p = 0.008). Furthermore, kidney resected part volume (OR 1.05, 95% CI 1.05-1.10, p = 0.033) and IOH time (OR 1.11, 95% CI 1.03-1.19, p = 0.005) were identified as risk factors for postoperative CKD. Conclusions. Patients after PN are at an increased risk of CKD development. Most commonly, postoperative CKD occurs in the first 6 months after PN and appears stable after 12 months of follow-up. Blood loss > 500 ml during PN, IOH and resected kidney volume can have an impact on postoperative RF and increase the risk of CKD.

Overview of clinical management for older patients with renal cell carcinoma

The rapidly increasing pool of older patients being diagnosed with and surviving their cancer is creating many challenges. Regarding localized renal cell carcinoma, surgery is considered as gold standard treatment options even in older men, whereas active surveillance and ablation therapy are alternative options for a proportion of these patients. With regard to advanced disease, anti-vascular endothelial growth factor tyrosine kinase inhibitors (VEGFR-TKI) and immune check point inhibitor are standard treatment modalities, although treatment choice from multiple regimens and prevention of adverse events need to be considered. Better assessment techniques, such as comprehensive geriatric assessment to meet the unique needs of older patients, are a central focus in the delivery of high-quality geriatric oncology care. Through this process, shared decision-making should be adopted in clinical care to achieve optimal goals of care that reflect patient and caregiver hopes, needs and preferences. It is necessary to continue investigating oncological outcomes and complications associated with treatment in this population to ensure appropriate cancer care. In this narrative review, we completed a literature review of the various treatments for renal cell carcinoma in older patients that aimed to identify the current evidence related to the full range of the treatments including active surveillance, surgery, ablation therapy and systemic therapy. Prospectively designed studies and studies regarding geriatric assessment were preferentially added as references. Our goals were to summarize the real-world evidence and provide a decision framework that guides better cancer practices for older patients with renal cell carcinoma.

Expanding the Role of Ultrasound for the Characterization of Renal Masses

The incidental detection of renal masses has been steadily rising. As a significant proportion of renal masses that are surgically treated are benign or indolent in nature, there is a clear need for better presurgical characterization of renal masses to minimize unnecessary harm. Ultrasound is a widely available and relatively inexpensive real-time imaging technique, and novel ultrasound-based applications can potentially aid in the non-invasive characterization of renal masses. Evidence acquisition: We performed a narrative review on novel ultrasound-based techniques that can aid in the non-invasive characterization of renal masses. Evidence synthesis: Contrast-enhanced ultrasound (CEUS) adds significant diagnostic value, particularly for cystic renal masses, by improving the characterization of fine septations and small nodules, with a sensitivity and specificity comparable to magnetic resonance imaging (MRI). Additionally, the performance of CEUS for the classification of benign versus malignant renal masses is comparable to that of computed tomography (CT) and MRI, although the imaging features of different tumor subtypes overlap significantly. Ultrasound molecular imaging with targeted contrast agents is being investigated in preclinical research as an addition to CEUS. Elastography for the assessment of tissue stiffness and micro-Doppler imaging for the improved detection of intratumoral blood flow without the need for contrast are both being investigated for the characterization of renal masses, though few studies have been conducted and validation is lacking. Conclusions: Several novel ultrasound-based techniques have been investigated for the non-invasive characterization of renal masses. CEUS has several advantages over traditional grayscale ultrasound, including the improved characterization of cystic renal masses and the potential to differentiate benign from malignant renal masses to some extent. Ultrasound molecular imaging offers promise for serial disease monitoring and the longitudinal assessment of treatment response, though this remains in the preclinical stages of development. While elastography and emerging micro-Doppler techniques have shown some encouraging applications, they are currently not ready for widespread clinical use.

A Nomogram for the Prediction of Intermediate Significant Renal Function Loss After Robot-assisted Partial Nephrectomy for Localized Renal Tumors: A Prospective Multicenter Observational Study (RECORd2 Project)

BACKGROUND

Robot-assisted partial nephrectomy (RAPN) is increasingly adopted for the treatment of localized renal tumors; however, rates and predictors of significant renal function (RF) loss after RAPN are still poorly investigated, especially at a long-term evaluation.

OBJECTIVE

To analyze the predictive factors and develop a clinical nomogram for predicting the likelihood of ultimate RF loss after RAPN.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively evaluated all patients treated with RAPN in a multicenter series (RECORd2 project).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Significant RF loss was defined as >25% reduction in estimated glomerular filtration rate (eGFR) from preoperative assessment at 48th month follow-up after surgery. Uni- and multivariable logistic regression analyses for RF loss were performed. The area under the receiving operator characteristic curve (AUC) was used to quantify predictive discrimination. A nomogram was created from the multivariable model.

RESULTS AND LIMITATIONS

A total of 981 patients were included. The median age at surgery was 64.2 (interquartile range [IQR] 54.3-71.4) yr, and 62.4% of patients were male. The median Charlson Comorbidity Index (CCI) was 1 (IQR 0-2), 12.9% of patients suffered from diabetes mellitus, and 18.6% of patients showed peripheral vascular disease (PVD). The median Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score was 7 (IQR 7-9). Imperative indications to partial nephrectomy were present in 3.6% of patients. Significant RF loss at 48th month postoperative evaluation was registered in 108 (11%) patients. At multivariable analysis, age (p = 0.04), female gender (p < 0.0001), CCI (p < 0.0001), CCI (p < 0.0001), diabetes (p < 0.0001), PVD (p < 0.0001), eGFR (p = 0.02), imperative (p = 0.001) surgical indication, and PADUA score (p < 0.0001) were found to be predictors of RF loss. The developed nomogram including these variables showed an AUC of 0.816.

CONCLUSIONS

We developed a clinical nomogram for the prediction of late RF loss after RAPN using preoperative and surgical variables from a large multicenter dataset.

PATIENT SUMMARY

We developed a nomogram that could represent a clinical tool for early detection of patients at the highest risk of significant renal function impairment after robotic conservative surgery for renal tumors.

Predicting the risk of postoperative acute kidney injury: development and assessment of a novel predictive nomogram

OBJECTIVE

This study aimed to establish and internally verify the risk nomogram of postoperative acute kidney injury (AKI) in patients with renal cell carcinoma.

METHODS

We retrospectively collected data from 559 patients with renal cell carcinoma from June 2016 to May 2019 and established a prediction model. Twenty-six clinical variables were examined by least absolute shrinkage and selection operator regression analysis, and variables related to postoperative AKI were determined. The prediction model was established by multiple logistic regression analysis. Decision curve analysis was conducted to evaluate the nomogram.

RESULTS

Independent predictors of postoperative AKI were smoking, hypertension, surgical time, blood glucose, blood uric acid, alanine aminotransferase, estimated glomerular filtration rate, and radical nephrectomy. The C index of the nomogram was 0.825 (0.790-0.860) and 0.814 was still obtained in the internal validation. The nomogram had better clinical benefit when the intervention was decided at the threshold probabilities of >4% and <79% for patients and doctors, respectively.

CONCLUSIONS

This novel postoperative AKI nomogram incorporating smoking, hypertension, the surgical time, blood glucose, blood uric acid, alanine aminotransferase, the estimated glomerular filtration rate, and radical nephrectomy is convenient for facilitating the individual postoperative risk prediction of AKI in patients with renal cell carcinoma.

The impact of intraoperative bleeding on the risk of chronic kidney disease after nephron-sparing surgery

PURPOSE

The current literature regarding the effect of blood loss (eBL) after nephron-sparing surgery (NSS) on long-term renal function is scarce. We tested the effect of eBL on the risk of developing chronic kidney disease (CKD) after NSS.

METHODS

Within an institutional prospectively maintained database, we identified 215 patients treated with NSS for cT₁N₀M₀ renal mass at one European high-volume center. Multivariable logistic regression models tested the effect of eBL on the risk of developing CKD, after accounting for surgical complexity, individual clinical characteristics, and surgical experience. Multivariable linear regression models identified predictors of eBL.

RESULTS

After a median follow-up of 36 months, 55 (25.6%) patients experienced CKD after surgery. At multivariable analyses, eBL independently predicted higher risk of CKD after NSS (odds ratio [OR]: 1.16; 95% confidence intervals [CI] 1.04-1.30; p < 0.01). Specifically, the relationship between eBL and probability of CKD emerged as nonlinear, with a plateau from 0 to 500 mL of eBL and an increase afterward. When multivariable linear regression analyses investigated predictors of eBL, hypertension (Est: 127, 95% CI 12-242; p = 0.03), clinical size (Est: 47, 95% CI 7-87; p = 0.02), and PADUA score (Est: 42; 95% CI 4-80 p = 0.03) achieved independent predictor status for higher intraoperative eBL. Conversely, surgical experience was associated with lower eBL (p = 0.01).

CONCLUSIONS

Intraoperative bleeding is independently associated with the risk of developing CKD after surgery, even after adjustment for well-known predictors of renal failure and tumor complexity. Hence, strategies aimed at maximally reducing such adverse events deserve special consideration.