Hypertension and diabetes mellitus are not associated with worse renal functional outcome after partial nephrectomy in patients with normal baseline kidney function

Renal functional outcomes after nephrectomy in patients with localized renal cell carcinoma and diabetes mellitus: a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVE

Diabetes mellitus (DM), one of the most common comorbidities in patients with renal cell carcinoma (RCC), was proven to be an important prognostic factor of overall survival for these patients. Regarding the influence on renal function after nephrectomy, evidence is still scant. This systematic review and meta-analysis was conducted to provide a more reliable analysis of the association between DM and long-term renal functional outcomes after nephrectomy.

METHODS

The PubMed, Web of Science, Embase and Cochrane Library (CENTRAL) databases were searched for eligible studies from inception to January 2023. Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted to evaluate the association between DM and renal functional outcomes using a random effects model. Stata 17.0 software was used for statistical analysis.

RESULTS

The meta-analysis included thirteen studies consisting of 8562 RCC patients who underwent nephrectomy. Preoperative comorbidity of DM was significantly associated with poor renal functional outcomes (HR = 1.91, 95% CI 1.48-2.48, p < 0.0001), regardless of ethnicity, follow-up time, body mass index (BMI) and age. However, in the radical nephrectomy subgroup, DM was not significantly associated with renal function decline (HR = 1.91, 95% CI 0.93-3.90, p = 0.0781).

CONCLUSIONS

The aggregate evidence indicated that preexisting DM may be associated with poor renal functional outcomes in patients with RCC after nephrectomy, especially in patients receiving partial nephrectomy. Urologists should focus more on the glycemic management of these patients after nephrectomy. More high-quality studies are needed to explore the influence of DM on renal function outcomes in postoperative patients.

Is Hypertension Associated with Worse Renal Functional Outcomes after Minimally Invasive Partial Nephrectomy? Results from a Multi-Institutional Cohort

Background: Hypertension (HTN) is a global public health issue. There are limited data regarding the effects of HTN in patients undergoing partial nephrectomy (PN) for renal tumors. To address this void, we tested the association between HTN and renal function after minimally invasive PN (MIPN). Methods: Using a multi-institutional database (2007–2017), we identified patients aged ≥ 18 years with a diagnosis of cT1 renal tumors treated with MIPN. Kaplan–Meier plots and Cox regression models addressed newly-onset CKD stage ≥ 3b or higher (sCKD). All analyses were repeated after 1:1 propensity score matching (PSM). Results: Overall, 2144 patients were identified. Of those, 35% (n = 759) were yes-HTN. Yes-HTN patients were older, more frequently male and more often presented with diabetes. Yes-HTN patients harbored higher RENAL nephrometry scores and higher cT stages than no-HTN patients. Conversely, yes-HTN patients exhibited lower preoperative eGFRs. In the overall cohort, five-year sCKD-free survival was 86% vs. 94% for yes-HTN vs. no-HTN, which translated into a multivariable HR of 1.67 (95% CI: 1.06–2.63, p = 0.026). After 1:1 PSM, virtually the same results were observed (HR 1.86, 95% CI: 1.07–3.23, p = 0.027). Conclusions: Yes-HTN patients exhibited worse renal function after MIPN when compared to their no-HTN counterparts. However, these observations need to be further tested in a prospective cohort study.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Measuring volumetric segmentation changes in the ipsilateral and contralateral kidney postpartial nephrectomy

OBJECTIVE

To analyze the volumetric changes of the ipsilateral and contralateral kidneys and their effect on functional outcome post partial nephrectomy using segmentation analysis.

PATIENTS AND METHODS

We have analyzed the data of 119 patients from a single surgeon series of partial nephrectomy patients. Median follow-up was 11.40 months. Patients with bilateral tumors, and solitary kidney were excluded from analysis. Volumetric measurements were performed using a semiautomated tissue segmentation tool. A simple linear regression model to assess the predictors for parenchymal volume loss (PVL). A multivariable linear regression model was used to evaluate the association between PVL and warm ischemia time (WIT), controlling for other factors.

RESULTS

Mean WIT was 12.09 ± 4.40 minutes and the mean percentage decrease in the volume of the operated kidney was 16.99 ± 13.49%. WIT (β = 1.24, P < 0.001) and tumor complexity (simple vs. intermediate, β = 0.06, P = 0.984; simple vs. high, β = 11.62,P = 0.007) were associated with PVL. A 1 minute increase in WIT was associated with an increase in the percentage volume loss in the operated kidney by 1.38% (β = 1.20, P < 0.001). Patients with high tumor complexity (β = 11.17, P = 0.009) had a significantly higher percentage volume loss compared to patients with simple tumor complexity. Ipsilateral PVL (β = -0.35, P = 0.015) and male gender (β = -9.89, P = 0.021) were associated with change in eGFR. After adjusting for confounders, % volume loss (β = -0.32, P < 0.001) remained a significant predictor for contralateral hypertrophy.

CONCLUSION

Tumor complexity results in higher WIT and increased PVL as measured by volumetric segmentation. PVL is a key factor associated with functional outcome, and is directly linked to WIT. Increased PVL is also associated with decreased contralateral hypertrophy. Prospective studies with larger samples sizes will be required to validate our findings.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

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

RESULTS AND LIMITATIONS

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

CONCLUSIONS

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

PATIENT SUMMARY

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

Metabolic Syndrome Predicts Worse Perioperative Outcomes in Patients Treated With Partial Nephrectomy for Renal Cell Carcinoma

OBJECTIVE

To test the association between metabolic syndrome (MetS) and its components (high blood pressure, body mass index [BMI]  ≥ 30, altered fasting glucose, low high-density lipoprotein cholesterol and high triglycerides) on perioperative outcomes after partial nephrectomy (PN).

METHODS

Within the National Inpatient Sample database (2000-2015) we identified all PN patients. First, temporal trends of MetS were reported. Second, the effect of MetS components was tested in multivariable logistic regression models predicting overall and specific perioperative complications. Third, we tested for dose-response from the concomitant effect of multiple MetS components. All models were weighted and adjusted for clustering, as well as all available patient and hospital characteristics.

RESULTS

Of 25,875 patients: (1) 59.3% had high blood pressure, (2) 14.7% had BMI  ≥ 30, (3) 21.7% had altered fasting glucose, (4) 20.2% had high triglycerides, and (5) <0.01% had low high-density lipoprotein cholesterol. One vs 2 vs 3 vs 4 MetS components were recorded in 34.9% vs 22.9% vs 8.9% vs 2.2% patients. Of all, 11.1% exhibited  ≥ 3 components and qualified for MetS. The rates of MetS increased over time (estimated annual percentage changes: +12.0%;P <.001). The 4 tested MetS components (high blood pressure, BMI  ≥ 30, altered fasting glucose, and high triglycerides) achieved independent predictor status in multivariable models predicting overall, cardiac, miscellaneous medical, vascular, and respiratory complications, as well as transfusions. Moreover, a statistically significant dose-response was confirmed for the same endpoints.

CONCLUSION

MetS and its components consistently and strongly predict perioperative complications after PN. Moreover, the strength of the effect was directly proportional to the number of MetS components exhibited by each individual patient, even if formal MetS diagnosis of  ≥ 3 components has not been met.