Tumor Location Does Not Affect Long-Term Renal Function After Partial Nephrectomy

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

The effect of zero-ischaemia laparoscopic minimally invasive partial nephrectomy using the modified sequential preplaced suture renorrhaphy technique on long-term renal functions

Introduction

Laparoscopic minimally invasive partial nephrectomy (MIPN) is the preferred technique in renal surgery, especially T1 phase kidney tumours, and it is recommended for the protection of renal functions in methods that do not involve ischaemia.

Aim

To evaluate long-term renal functions of zero-ischaemia laparoscopic MIPN patients who underwent a modified sequential preplaced suture renorrhaphy technique.

Material and methods

In a total of 17 renal units in 16 patients with kidney tumours that were determined incidentally and did not cause any complaints, the masses were extracted via laparoscopic partial nephrectomy (LPN) using the modified sequential preplaced suture renorrhaphy technique. Creatinine and estimated glomerular filtration rate (eGFR) values of the patients were measured preoperatively and on the first day and after 12 months postoperatively, and the results were compared.

Results

The differences between the pre- and postoperative values were statistically significant (p = 0.033, p = 0.045), but the changes in postoperative creatinine and eGFR values were clinically insignificant. While the differences between preoperative and first-day postoperative creatinine and eGFR values were found to be statistically significant (p = 0.039, p = 0.042, respectively), a statistically significant difference was not detected between preoperative and 12-month postoperative creatinine and eGFR values (p = 0.09, p = 0.065, respectively). The global percentage of functional recovery was measured as 92.5% on the first day and 95.9% at the 12^th month.

Conclusions

The modified sequential preplaced suture renorrhaphy technique is an effective, reliable method for avoiding complications and preserving renal functions and nephrons in appropriate patients.

Impact of warm versus cold ischemia on renal function following partial nephrectomy

INTRODUCTION

We evaluated renal function following partial nephrectomy with cold ischemia (CI) versus warm ischemia (WI).

METHODS

Data were collected from 1,396 patients at six institutions who underwent partial nephrectomy for a renal mass with normal contralateral kidney to evaluate percent change in glomerular filtration rate (GFR) at 3-18 months. A multivariate linear regression model tested the association of percent change GFR with clinical, operative, and pathologic factors.

RESULTS

A total of 874 patients (63 %) underwent PN with CI and 522 (37 %) with WI. All patients undergoing laparoscopic and robotic-assisted partial nephrectomy (n = 443) had WI, whereas 92 % of open partial nephrectomy patients (n = 953) had CI. The CI group had a lower mean baseline GFR (72 vs. 80 ml/min/1.73 m(2)), longer median ischemia time (33 vs. 29 min), and larger mean tumor size (3.2 vs. 2.9 cm) with more advanced pathologic stage (T1b-T3: 25 vs. 16 %) (all p values <0.001). Patients with CI and WI demonstrated 12.3 and 10.1 % reductions in renal function from baseline, respectively (p = 0.067). Increasing age, female gender, and increasing tumor size were associated with reduction in renal function (all p values <0.001). Neither renal hypothermia nor operative technique independently predicted reduced renal function. Sensitivity analyses limited to ischemia time >30 min, baseline estimated glomerular filtration rate <60 ml/min/1.73 m(2), or tumors >4 cm did not significantly alter the findings.

CONCLUSIONS

Increasing age, female gender, and larger tumor size independently predict a decrease in renal function following partial nephrectomy with a normal contralateral kidney. Within the limitations of a non-randomized comparison, including lack of parenchymal preservation percentage, neither surgical approach (open or laparoscopic) nor presence of hypothermia appears to be associated with long-term renal function.

Retroperitoneal laparoscopic partial nephrectomy for moderately complex renal hilar tumors

OBJECTIVES

To report our initial experience in retroperitoneal laparoscopic partial nephrectomy (LPN) for moderately complex renal hilar tumors and summarize the feasibility of the retroperitoneal laparoscopic approach.

MATERIALS AND METHODS

14 patients with renal hilar tumors underwent retroperitoneal LPN between June 2010 and January 2012 at our institution. All of the masses were confirmed in the hilar location by computed tomography preoperatively and then evaluated with the R.E.N.A.L. nephrometry scoring system; all were defined as moderately complex lesions. A three-port retroperitoneal approach with a dorsal incision was used in all cases. Patient baseline demographics, perioperative outcomes and pathological characteristics were recorded based on a retrospective data collection and telephone interview.

RESULTS

All operations were performed successfully without conversion to radical nephrectomy or open surgery. Only two complications of perirenal fluid collection occurred, but the patients recovered with active surveillance. Mean operative time was 134.3 min, mean estimated blood loss 133.2 ml, mean warm ischemia time 30.6 min and mean retroperitoneal drainage 2.2 days. Mean postoperative hospital stay was 4.7 days. No recurrence or metastasis occurred in these patients at a mean follow-up of 18.6 months.

CONCLUSIONS

Our initial experience suggests that retroperitoneal LPN is a feasible, safe and effective procedure for moderately complex renal hilar tumors. Although it remains technically challenging, this approach can be recommended in some complex cases when in experienced hands.

Percutaneous radiofrequency ablation does not affect glomerular filtration rate

PURPOSE

To study short- and intermediate-term global renal function in patients undergoing a single percutaneous radiofrequency ablation (pRFA) for a solitary renal parenchymal tumor.

MATERIALS AND METHODS

We reviewed the records of 62 patients who underwent a single pRFA for solitary renal parenchymal tumor. We used the abbreviated Modified Diet for Renal Disease equation to calculate baseline, 1-month, and 1-year glomerular filtration rate (GFR). We defined normal as >60, moderately diminished as 45-60, and severely diminished GFR as <45 cc/minute/1.73 m². We used the Wilcoxon paired rank sum method to compare 1-month and 1-year GFR to baseline. We fit a linear regression model to test the association of lesion size to GFR controlling for lesion location and baseline GFR.

RESULTS

There was no difference in GFR from baseline at 1 month or 1 year (55 vs. 58 cc/minute/1.73 m², p=0.24 and 55 vs. 57 cc/minute/1.73 m², p=0.8, respectively). Tumor size did not affect GFR at 1 month or 1 year after controlling for lesion location and baseline GFR.

CONCLUSIONS

A single application of pRFA does not affect GFR in the short or intermediate term.

Factors predicting renal functional outcome after partial nephrectomy

PURPOSE

Compared to radical nephrectomy, partial nephrectomy better preserves renal parenchyma and function. Although several clinical factors may impact renal function after partial nephrectomy including preoperative function, age, gender and comorbidities, the contributions of tumor and surgical factors have not been well studied. We evaluate independent factors predicting functional outcomes after partial nephrectomy.

MATERIALS AND METHODS

Preoperative and all postoperative serum creatinine values for 1,169 patients undergoing partial nephrectomy were used to estimate glomerular filtration rate. Postoperative nadir glomerular filtration rate and ultimate glomerular filtration rate were analyzed using multiple pertinent covariates.

RESULTS

Median preoperative, postoperative nadir and ultimate glomerular filtration rates were 77, 57 and 71 ml per minute per 1.73 m(2), respectively. Increasing age, gender, lower preoperative glomerular filtration rate, solitary kidney, tumor size, ischemia time and longer time to nadir glomerular filtration rate significantly predicted postoperative nadir glomerular filtration rate and ultimate glomerular filtration rate. Acute loss of renal function predicted lower ultimate glomerular filtration rate. In the entire cohort, in patients with normal preoperative renal function, and in those with baseline stage 3 and those with stage 4 chronic kidney disease the incidence of postoperative acute kidney injury after partial nephrectomy was 3.6%, 0.8%, 6.2% and 34%, and the incidence of chronic end stage renal disease after partial nephrectomy was 2.5%, 0.1%, 3.7% and 36%, respectively.

CONCLUSIONS

Lower preoperative glomerular filtration rate, solitary kidney, older age, gender, tumor size and longer ischemic interval all predicted lower glomerular filtration rate after partial nephrectomy. Therefore, duration of renal ischemia is the strongest modifiable surgical risk factor for decreased renal function after partial nephrectomy, and efforts to limit ischemic time and injury should be pursued in open and laparoscopic partial nephrectomy.

Effect of baseline glomerular filtration rate on survival in patients undergoing partial or radical nephrectomy for renal cortical tumors

OBJECTIVE

To evaluate the effect of baseline renal function and comorbidity index on survival in patients with renal tumors.

PATIENTS AND METHODS

We retrieved demographic, clinicopathologic, body mass index (BMI), and comorbidity data (assessed by Charlson-Romano index and hypertension) for 1479 patients who underwent partial or radical nephrectomy between January 4, 1995, and June 9, 2005, for localized renal tumors. We used the abbreviated Modified Diet and Renal Disease equation to estimate glomerular filtration rate (eGFR) using the last preoperative serum creatinine measurement. Body mass index and eGFR time trends were analyzed with linear regression. The effect of BMI, comorbidity, and baseline eGFR on disease-free and overall survival was studied using Cox regression controlling for pathologic stage, nodal status, and metastasis.

RESULTS

Over a 10-year interval, median BMI increased from 27 (interquartile range [IQR], 24-31) to 28 (IQR, 25-31; P=.004), and median baseline eGFR decreased from 70 (IQR, 58-80) to 63 mL/min per 1.73 m(2) (IQR, 57-78; P<.001). Multivariate regression demonstrated an association between year of surgery and baseline eGFR (P<.001) even after adjusting for age, sex, comorbidity, BMI, and tumor size. We repeated the analysis for patients aged 18 to 70 years, and this association persisted (P<.001). Baseline eGFR, BMI, and comorbidity were not associated with disease-free survival after controlling for stage. However, moderately reduced baseline eGFR (45-60 mL/min per 1.73 m(2)) and severely reduced eGFR (<45 mL/min per 1.73 m(2)) were significantly associated with overall survival (hazard ratio, 1.5; P<.003; and hazard ratio, 2.8; P<.001; respectively).

CONCLUSION

Baseline eGFR has declined over the past decade. Nephron-sparing techniques should be considered for patients with severely diminished baseline eGFR.

Cytoreductive partial nephrectomy does not undermine cancer control in metastatic renal cell carcinoma: a population-based study

OBJECTIVES

We examined the population-based rates of cancer-specific survival in patients with metastatic renal cell carcinoma (MRCC) treated with either partial (PN) or radical cytoreductive nephrectomy (RN).

METHODS

Patients diagnosed with MRCC and treated with either PN or RN were identified within nine SEER cancer registries. Matched and unmatched Kaplan-Meier survival analyses, as well as multivariable Cox regression models compared the effect of RN (n = 1997, 97.8%) vs. PN (n = 46, 2.2%) on cancer-specific survival (CSS). Covariates consisted of age, gender, community type (rural vs urban), race, Surveillance, Epidemiology, and End Results (SEER) registry, tumor size and year of diagnosis.

RESULTS

In multivariable unmatched Cox regression analyses, no statistically significantly difference was found in CSS between the two groups (hazard ratio [HR] 1.40, P = .16). Similarly, no difference in CSS was found in the matched analyses (HR 1.35, log rank P = .34).

CONCLUSION

Cytoreductive PN does not appear to undermine survival in patients with MRCC.