Renal Ischemia and Function After Partial Nephrectomy: A Collaborative Review of the Literature

CONTEXT

Partial nephrectomy (PN) is the current gold standard treatment for small localized renal tumors.; however, the impact of duration and type of intraoperative ischemia on renal function (RF) after PN is a subject of significant debate.

OBJECTIVE

To review the current evidence on the relationship of intraoperative ischemia and RF after PN.

EVIDENCE ACQUISITION

A review of English-language publications on renal ischemia and RF after PN was performed from 2005 to 2014 using the Medline, Embase, and Web of Science databases. Ninety-one articles were selected with the consensus of all authors and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

EVIDENCE SYNTHESIS

The vast majority of reviewed studies were retrospective, nonrandomized observations. Based on the current literature, RF recovery after PN is strongly associated with preoperative RF and the amount of healthy kidney parenchyma preserved. Warm ischemia time (WIT) is modifiable and prolonged warm ischemia is significantly associated with adverse postoperative RF. Available data suggest a benefit of keeping WIT <25min, although the level of evidence to support this threshold is limited. Cold ischemia safely facilitates longer durations of ischemia. Surgical techniques that minimize or avoid global ischemia may be associated with improved RF outcomes.

CONCLUSIONS

Although RF recovery after PN is strongly associated with quality and quantity of preserved kidney, efforts should be made to limit prolonged WIT. Cold ischemia should be preferred when longer ischemia is expected, especially in presence of imperative indications for PN. Additional research with higher levels of evidence is needed to clarify the optimal use of renal ischemia during PN.

PATIENT SUMMARY

In this review of the literature, we looked at predictors of renal function after surgical resection of renal tumors. There is a strong association between the quality and quantity of renal tissue that is preserved after surgery and long-term renal function. The time of interruption of renal blood flow during surgery is an important, modifiable predictor of postoperative renal function.

The ERUS Curriculum for Robot-assisted Partial Nephrectomy: Structure Definition and Pilot Clinical Validation

BACKGROUND

No validated training program for robot-assisted partial nephrectomy (RAPN) exists.

OBJECTIVE

To define the structure and provide a pilot clinical validation of a curriculum for robot-assisted partial nephrectomy (RAPN).

DESIGN, SETTING, AND PARTICIPANTS

A modified Delphi consensus methodology involving 27 experts defined curriculum structure. One trainee completed the curriculum under the mentorship of an expert. A total of 40 patients treated with curriculum RAPN (cRAPN) were compared with 160 patients treated with standard of care (sRAPN).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

To define curriculum structure, consensus was defined as ≥90% expert agreement. To investigate curriculum safety, perioperative morbidity, renal function, and pathologic outcomes were evaluated. To investigate curriculum efficacy, RAPN steps and modules attempted and completed by the trainee were evaluated. Propensity score matching identified comparable cRAPN and sRAPN cases. Mann-Whitney U test, chi-square test, and linear regression were used to investigate the impact of the curriculum on patient's outcome and the impact of trainee's experience on surgical independence.

RESULTS AND LIMITATIONS

Consensus-based key statements defined curriculum structure. No difference was recorded between cRAPN and sRAPN with respect to intraoperative or overall and grade-specific postoperative complications, blood loss, ischemia time, postoperative estimated glomerular filtration rate, and positive surgical margins (all p>0.05). Conversely, operative time was longer after cRAPN (p<0.0001). The trainee completed all phases of the curriculum and the trainee's experience was associated with more steps attempted/completed and increasing complexity of module attempted/completed (all p<0.0001). The limitations of the study are the enrolment of a single trainee at a single institution and the small sample size. Accordingly, the large confidence intervals observed cannot exclude inferior outcomes in case of cRAPN and further study is required to confirm safety.

CONCLUSIONS

The European Association of Urology (EAU) Robotic Urology Section (ERUS) curriculum for RAPN can protect patients from suboptimal outcome during the learning curve of the surgeon and can aid surgeons willing to start an RAPN program.

PATIENT SUMMARY

Patients should be aware that structured training programs can reduce the risk of suboptimal outcome due to the learning curve of the surgeon.

Trends and perioperative outcomes for laparoscopic and robotic nephrectomy using the National Surgical Quality Improvement Program (NSQIP) database

OBJECTIVES

We sought to examine the trends in perioperative outcomes of kidney cancer surgery stratified by type (radical nephrectomy [RN] vs. partial nephrectomy [PN]) and approach (open vs. minimally invasive).

METHODS

We queried the National Surgical Quality Improvement Program database to identify kidney cancer operations performed from 2005 to 2011. We examined 30-day perioperative outcomes including operative time, transfusion rate, length of stay, major morbidity (cardiovascular, pulmonary, renal, and infectious), and mortality.

RESULTS

A total of 2,902 PN and 5,459 RN cases were identified. The use of PN increased over time, accounting for 39% of all nephrectomies in 2011. Minimally invasive approaches also increased over time for both RN and PN. Open surgery was associated with increased length of stay, receipt of transfusion, major complications, and perioperative mortality. Resident involvement and open approach were independent predictors of major complications for both PN and RN. Additionally, the presence of a medical comorbidity was also a risk factor for complications after RN. The overall complication rates decreased for all approaches over the study period.

CONCLUSIONS

Minimally invasive approaches to kidney cancer renal surgery have increased with favorable outcomes. The safety of open and minimally invasive PN improved significantly over the study period. Although pathologic features cannot be determined from this data set, these data show that complications from renal surgical procedures are decreasing in an era of increasing use.

Robot-assisted Partial Nephrectomy for Complex (PADUA Score ≥10) Tumors: Techniques and Results from a Multicenter Experience at Four High-volume Centers

BACKGROUND

Robot-assisted partial nephrectomy (RAPN) represents a widely accepted minimally invasive alternative to open and laparoscopic surgery for the treatment of clinically localized renal tumors.

OBJECTIVE

To assess the feasibility of RAPN in a contemporary series of patients with highly complex tumors (PADUA score ≥10) treated at four high-volume robotic surgery institutions.

DESIGN, SETTING, AND PARTICIPANTS

Data from a prospectively maintained multi-institutional database on patients subjected to RAPN between 2010 and 2017 were reviewed. For the scope of this analysis, only patients with highly complex renal tumors, defined as a PADUA score between 10 and 14, were included.

SURGICAL PROCEDURE

RAPN was performed with the da Vinci Si or Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA) using novel technologies such as TilePro and near-infrared fluorescence imaging.

MEASUREMENTS

Intraoperative, postoperative, surgical, and oncological outcomes were collected. Predictors of optimal surgical outcomes defined according to the Margin Ischemia and Complications binary system (absence of Clavien-Dindo >2 complications, warm ischemia time [WIT] <20min, and absence of positive surgical margins) were determined using logistic regression models (LRMs).

RESULTS AND LIMITATIONS

Overall, 255 patients with complex renal tumors were included. The mean operative time was 165min and mean WIT was 18.6min. Overall, WIT was longer than 20min in 86 (33.7%) individuals, while a Clavien-Dindo >2 complication and positive surgical margins were observed in 13 (5.1%) and four (out of 211 patients with malignant histotypes; 1.9%) individuals, respectively. Optimal surgical outcomes were achieved in 158 (62.0%) patients. At a median follow-up of 28mo, one (0.4%) local and two (0.8%) distant recurrences of the disease were observed. In multivariable LRMs, extremely complex tumors (PADUA score 12-13) were associated with an increased likelihood of not achieving optimal outcomes (odds ratio: 2.31; p=0.024). Besides tumor complexity, male gender was also associated with a two-fold higher risk of not achieving optimal surgical outcomes (p=0.029).

CONCLUSIONS

In experienced hands, RAPN can be considered as an effective treatment option even in cases of complex renal lesions. However, increasing tumor complexity may affect the surgical outcomes in this highly selected patient population.

PATIENT SUMMARY

We reported our multicentric experience with robot-assisted partial nephrectomy (RAPN) in patients with complex renal tumors. We demonstrated that, in experienced hands, RAPN is a feasible and safe treatment option even in such patients. Novel technologies applied to RAPN may further extend the indications without compromising the outcomes.

A prospective comparison of the pathologic and surgical outcomes obtained after elective treatment of renal cell carcinoma by open or robot-assisted partial nephrectomy

OBJECTIVE

To prospectively compare surgical and pathologic outcomes obtained by elective robot-assisted (RAPN) or open partial nephrectomy (OPN) for small renal cell carcinoma (RCC).

MATERIALS AND METHODS

Between 2008 and 2010, after protocol design and patient consent, we prospectively collected clinical data for 100 patients who concurrently underwent either OPN (58) or RAPN (42) by an individual experienced surgeon. Clinical data included age, BMI, and past medical history. Operative data included operative time, warm ischemia time (WIT), and estimated blood loss (EBL). Postoperative outcomes included hospital stay (LOS), creatinine variation, Clavien complications, pathologic results, and survival. We stratified the complexity of the renal tumor using the R.E.N.A.L Nephrometry score.

RESULTS

Of note, RAPN was superior to OPN in terms of EBL (median 143 mL vs. 415; P < 0.001) and LOS (median 3.8 days vs. 6.8; P < 0.0001). The median WIT for the RAPN group was 17.5 minutes (vs. 17.1 OPN; P = 0.3)) and the mean strict operative time was 134.8 minutes (vs. 128.4 OPN; P = 0.097). Regarding immediate, early, and short-term complications, variation of creatinine levels, and pathologic margins, the rates were equivalent for both groups (P > 0.05). According to the R.E.N.A.L nephrometry scores, both groups (RAPN/OPN) had similar rates (%) of low (81/72.4) and intermediate (19/20.7) complexity tumors, though there were 4 high complexity tumors in OPN group (vs. 0; P = 0.03).

CONCLUSION

We found that RAPN is superior to the reference standard (OPN) surgical treatment of small RCCs in terms of blood loss and length of hospital stay with equivalent complications, warm ischemia time, and effect on renal function. Larger randomized trials with longer follow-up will give us further information and insight into the oncologic equivalence.

Diagnostic accuracy of ureteroscopic biopsy in predicting stage and grade at final pathology in upper tract urothelial carcinoma: Systematic review and meta-analysis

OBJECTIVE

To assess the accuracy of ureteroscopic (URS) biopsies in predicting stage and grade at final pathology in upper tract urothelial carcinoma (UTUC).

MATERIALS AND METHODS

The meta-analysis was performed in accordance with the PRISMA statement. Studies providing data on tumor stage and grade at URS biopsy and surgical specimens were included. The negative predictive value (NPV) implies concordance between the absence of subepithelial connective tissue invasion or the presence of low-grade tumors at URS biopsy and the absence of a muscle-invasive disease in the final pathology.

RESULTS

A total of 23 studies were included (3547 patients). The stage-to-stage match between URS biopsy/final pathology showed a positive predictive value (PPV) for cT1+/muscle-invasive disease of 94% (95% CI: 84%-100%) and a NPV for cTa-Tis/non-muscle-invasive disease of 60% (95% CI: 52%-68%). The grade-to-grade match between URS biopsy/final pathology was 66% (95% CI: 55%-77%) for low-grade (cLG/pLG) tumors and 97% (95% CI: 94%-98%) for high-grade (cHG/pHG) tumors. The PPV for cHG/muscle-invasive disease was 60% (95% CI: 54%-66%) and the NPV for cLG/non-muscle-invasive disease was 77% (95% CI: 73%-82%). The undergrading and understaging rates were 32% (95%CI: 25%-38%) and 46% (95% CI: 38%-54%), respectively.

CONCLUSIONS

There is a substantial correlation between tumor grade at URS biopsy and the final pathology. The identification of cHG tumors and subepithelial connective tissue invasion (cT1+) in URS biopsy showed a moderate and a strong correlation with invasive UTUC, respectively. Nevertheless, a certain risk of undergrading and understaging should be assumed.

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.

End-Stage Renal Disease After Renal Surgery in Patients with Normal Preoperative Kidney Function: Balancing Surgical Strategy and Individual Disorders at Baseline

Although nephron-sparing surgery (NSS) has demonstrated benefit in terms of renal function preservation, it is unclear whether NSS might also decrease the risk of end-stage renal disease (ESRD) relative to radical nephrectomy (RN). In the current paper, we aimed to report the rate and the predictors of ESRD after surgery, accounting for detailed individual baseline characteristics and comorbidities. A multi-institutional collaboration among five European tertiary care centers allowed study of 2027 patients with normal preoperative renal function and a clinically localized T1abN0M0 renal mass. Cox regression analyses were used to predict the risk of ESRD (defined as the onset of a postoperative estimated glomerular filtration rate <15ml/min per 1.73 m²) after adjusting for the individual baseline risk of developing chronic kidney disease. Univariable ESRD rates at 5 and 10 yr of follow-up were virtually equivalent for patients who underwent NSS (1.5% and 2.5%, respectively) versus RN (1.9% and 2.7%, respectively; hazard ratio [HR]: 0.8; 95% confidence interval [CI], 0.4-1.6). However, diabetes, smoking, uncontrolled hypertension, and other comorbidities were consistently more frequent in the NSS group relative to their RN counterparts. After adjusting for detailed baseline individual characteristics, NSS was shown to have an independent protective effect relative to RN (HR: 0.4; 95% CI, 0.2-0.8; p=0.02) at multivariable analyses.

PATIENT SUMMARY

After accounting for individual baseline characteristics, such as age, diabetes, uncontrolled hypertension, or other comorbidities, partial nephrectomy independently protects against end-stage renal disease and the consequent need for dialysis relative to radical nephrectomy.

Toward greater adoption of minimally invasive and nephron-sparing surgical techniques for renal cell cancer in the United States

PURPOSE

To examine national, population-based utilization trends of nephron-sparing and minimally invasive techniques for the surgical management of patients with adult renal cell cancer (RCC) in the United States.

METHODS

Linked data from the National Cancer Institute׳s Patterns of Care studies and the Area Health Resource File were used to evaluate trends of nephron-sparing and minimally invasive techniques in a sample of 1,110 patients newly diagnosed with American Joint Committee on Cancer stages I-II RCC, in 2004 and 2009, who underwent surgery. Descriptive statistics were used to assess patterns of surgery between 2004 and 2009. Multivariable logistic regression analyses were used to evaluate the associations between demographic, clinical, hospital, and area-level health care characteristics with surgery utilization, stratified by the subset of patients who were potentially eligible for partial nephrectomy (PN) vs. radical nephrectomy (RN) and laparoscopic RN (LRN) vs. open RN, respectively.

RESULTS

Between 2004 and 2009, PN use among stage I patients with tumors≤7cm increased from 29% to 41%, respectively (P = 0.22). Among patients with stage I tumors≤4cm, use of PN significantly increased from 43% in 2004 to 55% in 2009 (P≤0.05). Among patients with stage I tumors>4 to 7cm, laparoscopic partial nephrectomy increased from 8% to 15%, whereas LRN increased from 38% to 69%, between 2004 and 2009 (P = 0.07). Significant increases in LRN use were observed for both stage I (from 43% in 2004 to 58% in 2009; P≤0.05) and stage II patients (from 16% in 2004 to 47% in 2009; P≤0.01). Patients diagnosed at an older age, with larger tumors, non-clear cell RCC and who did not receive treatment in a hospital with residency training were significantly less likely to receive PN vs. RN; whereas, those diagnosed in 2009 with stage I disease were significantly more likely to receive LRN vs. open RN.

CONCLUSIONS

This study highlights a significant shift toward increased use of nephron-sparing and minimally invasive surgical techniques to treat patients with RCC in the United States. Our findings are among the first population-based reports in which most eligible patients with RCC received PN over RN. In light of the long-standing evidence on the improved patient outcomes, future investigation is warranted to identify the barriers to increased adoption of these nephron-sparing and minimally invasive approaches.

Nephron-sparing surgery for Wilms tumor: A systematic review

INTRODUCTION

Radical nephrectomy (RN, or total nephrectomy) is the current gold-standard surgical treatment for children with Wilms tumors (WT). However, nephron-sparing surgery (NSS, or partial nephrectomy) has recently been gaining increasing attention. The objective of this systematic review is to compare the effectiveness of NSS as compared with RN for the treatment of children with WT.

METHODS

We searched the Cochrane Controlled Trials Register, clinicaltrials.gov, MEDLINE, EMBASE, Google Scholar, and recently presented meeting abstracts for reports in English. The bibliographies of included studies were then hand-searched for any missed articles. The protocol was prospectively registered. Manuscripts were assessed and data abstracted in duplicate with differences resolved by the senior author. Owing to high heterogeneity among the final included studies, only a qualitative systematic review was performed; no formal meta-analysis was undertaken.

RESULTS

We identified 694 articles, 118 of which were selected for full-text review and 66 of which were included in the final analysis. Most studies were single- or multi-institution retrospective case series (60, 91%), with a small number of prospective cohort studies (6, 9%) and 1 administrative database analysis. Most studies were from Europe (27, 41%) or North America (21, 32%). Nearly half (32, 48%) of studies those were included were dated from 2010 or later. In total, data on 4,002 patients were included, of whom 1,040 (26%) underwent NSS and 2,962 (74%) underwent NSS. Reported rupture rates were similar between RN and NSS (13% vs. 7%), as were recurrence rates (12% vs. 11%) and survival rates (85% vs. 88%). However, these comparisons are limited by inherent biases in the design and reporting of most included studies.

CONCLUSIONS

Most contemporary studies reporting the use of NSS in children with WT report similar long-term outcomes to RN. However, most existing studies are limited by their small numbers, inconsistent reporting, and methodological biases. There are significant opportunities for future research on the use of NSS in children with WT, including issues related to surgical quality, optimal technique, timing and duration of chemotherapy, and variation in the use of NSS among centers.

Intravenous Mannitol Versus Placebo During Partial Nephrectomy in Patients with Normal Kidney Function: A Double-blind, Clinically-integrated, Randomized Trial

BACKGROUND

Mannitol is currently used as a renal protective agent to mitigate the effects of renal ischemia during nephron-sparing surgery (NSS). This routine practice lacks rigorous methodological study.

OBJECTIVE

To assess the effect on renal function outcomes after surgery of mannitol infusion prior to renal ischemia during NSS.

DESIGN, SETTING, PARTICIPANTS

This prospective, randomized, placebo-controlled, double-blind trial included 199 patients with a preoperative estimated glomerular filtration rate (eGFR) >45ml/min/1.73m² scheduled for NSS; the trial was conducted between July 2012 and July 2015.

INTERVENTION

Patients undergoing NSS were randomized to receive mannitol (12.5g) or placebo intravenously within 30min prior to renal vascular clamping.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the difference in eGFR (renal function) between the two groups at 6 mo following surgery assessed with an analysis of covariance model using preoperative eGFR, treatment group, and surgical approach as covariates.

RESULTS AND LIMITATIONS

At baseline, the median age of the patients was 58 yr, and the median eGFR was 88ml/min/1.73m². Comparing placebo with mannitol infusion, the adjusted difference of 0.2 eGFR units at 6 mo was not significant (p=0.9), with the upper bound of the 95% confidence interval (-3.1 to 3.5) excluding a clinically relevant effect of mannitol. Limitations include evaluation of a single mannitol dose and patients all had excellent preoperative renal function.

CONCLUSIONS

Intraoperative 12.5g mannitol infusion during NSS has no demonstrable clinical benefit when compared with standardized fluid hydration in patients with normal preoperative renal function, and its use in this setting is not warranted.

PATIENT SUMMARY

In this randomized trial, patients with normal kidney function who received mannitol during surgery to remove part of their kidney had no better kidney function 6 mo after surgery than those who did not receive mannitol. We conclude that this routine practice should be discontinued.

Oncologic and Functional Outcomes after Partial Nephrectomy Versus Radical Nephrectomy in T1b Renal Cell Carcinoma: A Multicenter, Matched Case-Control Study in Korean Patients

Purpose

The study was to compare the oncologic and functional outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) for pathologically proven T1b renal cell carcinoma using pair-matched groups.

Materials and Methods

We reviewed our prospectively maintained database for RN and PN in T1b renal tumors surgically treated between 1999 and 2011 at five institutions in Korea. Of 611 patients treated with PN or RN for a solitary and NX/N0 M0 renal mass (4-7 cm), 577 (PN, 100; RN, 477) patients with pathologically confirmed pT1b remained for analysis. Study subjects were grouped by PN or RN, then matched by age, sex, comorbidities, body mass index, tumor size and depth, histologic type, and preoperative estimated glomerular filtration rate (eGFR) using propensities score. To evaluate oncologic outcomes, overall survival (OS), cancer-specific survival (CSS), and progression-free survival (PFS) rates were analyzed. The functional outcomes were evaluated by postoperative eGFR.

Results

The median follow-up in the RN group was 48.1 and 42.6 months in the PN group. The estimated 10-year CSS rate (PN 85.7% vs. RN 84.4%, p=0.52) and 5- and estimated 10-year PFS rates (PN: 86.4% and 79.2% vs. RN: 86.0% and 66.1%, p=0.66) did not differ significantly between groups. The estimated 10-year OS rate was significantly higher in the PN group (85.7%) compared to the RN group (73.3%) (p=0.003). PN was less likely to induce new-onset chronic kidney disease (CKD) and end-stage CKD compared with RN.

Conclusion

Our study suggests that patients treated with PN demonstrate a superior OS rate and postoperative renal function with analogous CSS and PFS rates compared with pair-matched patients treated with RN.

Repeat nephron-sparing surgery for children with bilateral Wilms tumor

BACKGROUND

Renal insufficiency is a significant complication of Wilms tumor treatment in the 5% with bilateral disease. Nephron-sparing surgery (NSS) is recommended after neoadjuvant chemotherapy initially. However, the role of NSS in recurrent disease is unknown. We reviewed our experience to assess the feasibility and oncologic and functional outcomes of repeat NSS for children with recurrent disease.

METHODS

A retrospective review was performed of all children treated at our institution for bilateral, favorable histology (FH) Wilms tumor. Patients undergoing repeat NSS for locally recurrent disease were identified. The outcomes evaluated included tumor recurrence, renal function, and patient survival.

RESULTS

Since 2001, 36 children with bilateral FH Wilms tumor have been treated at our institution. Eight patients (22%) underwent repeat NSS for locally recurrent disease. Two patients had a second local recurrence and underwent a third NSS. Six patients are alive without disease (75%) with an average follow-up of 4.5years. Two patients have died, each with blastemal-predominant histology at repeat NSS. The surviving patients have normal renal function, although two patients require medical management of hypertension.

CONCLUSIONS

Our experience suggests that repeat NSS for local recurrence of FH bilateral Wilms tumor is feasible and affords acceptable oncologic outcome with preservation of renal function. However, more aggressive therapy may be required for patients whose recurrence has blastemal-predominant histology, given the poor outcome for these patients in our series.

Comparison of renal function detriments after local tumor ablation or partial nephrectomy for renal cell carcinoma

PURPOSE

Local tumor ablation (LTA) and partial nephrectomy (PN) represent treatment alternatives for patients diagnosed with small renal mass and both may result in renal function detriments. The aim of the study was to compare renal function detriments after LTA or PN.

METHODS

A Surveillance epidemiology and End Results-Medicare-linked retrospective cohort of 2850 T1 kidney cancer patients who underwent LTA or PN was abstracted. Short-term outcomes consisted of 30-day acute kidney injury (AKI) and 30-day dialysis rates. Long-term outcomes consisted of episodes of AKI, mild and moderate-severe chronic kidney disease (CKD), end-stage renal disease, hemodialysis and anemia in CKD. Analyses consisted of propensity score matching, logistic and Cox regression.

RESULTS

After propensity score matching, 1122 patients remained. The 30-day incidence of AKI was 4.6 % after LTA and 9.4 % after PN. In multivariable analyses (MVAs), LTA was associated with a lower AKI rate (OR 0.42; p = 0.001). The 30-day incidence of any dialysis was <2 % after either LTA or PN. In MVA, LTA was not associated with a lower rate of any dialysis (OR 0.43; p = 0.2). At long-term assessment, both the unadjusted and adjusted rates of all six examined end points were not different between LTA and PN (all p > 0.5).

CONCLUSIONS

LTA offers short-term protective effect from AKI. The short-term rates of any dialysis treatment are similar after either LTA or PN. At long-term assessment, LTA and PN renal function detriment rates are not different. Concern for long-term functional outcomes should not be a barrier for PN.

Three-dimensional Virtual Models' Assistance During Minimally Invasive Partial Nephrectomy Minimizes the Impairment of Kidney Function

Three-dimensional virtual models (3DVMs) are nowadays under scrutiny to improve partial nephrectomy (PN) outcomes. This report aims to analyze their impact on renal function preservation after minimally invasive PN. A total of 100 patients treated with minimally invasive PN with contrast-enhanced computed tomography from which a 3DVM was obtained, and having undergone baseline and 3rd month postoperative renal scans were prospectively enrolled and compared with a control group of 251 patients without 3DVMs. Weighted differential of pre- and postoperative renal scan-based effective renal plasmatic flow (b-WD ERPF) was calculated, according to the availability of 3DVMs and PADUA risk category. Multivariable logistic regression (MLR) models predicting a significant loss of renal function (LORF; ERPF drop >20%) were performed, overall and according to PADUA risk categories. The b-WD ERPF of the 3DVM group showed significantly lower LORF (-10%) than that of the control group (-19.6%, p =  0.02). In MLR, the availability of a 3DVM was found to be the only protective factor against a significant LORF (odds ratio [OR] = 0.3, p =  0.002). Moreover, after stratification as per tumor surgical complexity, this protective role was observed in both PADUA 8-9 and ≥10 category risk patients (OR = 0.3, p =  0.03 and OR = 0.1, p =  0.01). PATIENT SUMMARY: The drop in operated kidney function was significantly lower in surgeries assisted by three-dimensional virtual models (3VDMs), indicating that the availability of a 3VDM is the only protective factor against a significant functional damage.

Perioperative and Mid-term Oncological and Functional Outcomes After Partial Nephrectomy for Complex (PADUA Score ≥10) Renal Tumors: A Prospective Multicenter Observational Study (the RECORD2 Project)

BACKGROUND

Partial nephrectomy (PN) for complex renal masses has a non-negligible risk of perioperative complications. Furthermore, late functional and oncological outcomes of patients submitted to these challenging surgeries still remain to be determined.

OBJECTIVES

To report the perioperative and mid-term oncological and functional outcomes of PN for complex masses (Preoperative Aspects and Dimensions Used for an Anatomical [PADUA] score≥10) in a large multicenter prospective observational study.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively evaluated patients treated with PN for complex renal tumors at 26 urological centers (Registry of Conservative and Radical Surgery for Cortical Renal Tumor Disease [RECORD2] project).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariate logistic regression analyses explored the predictors of surgical complications. Multivariable Cox regression analyses estimated the hazard of renal function loss and disease recurrence. Kaplan-Meier estimates assessed the probability of survival.

RESULTS AND LIMITATIONS

In total, 410 patients who underwent PN for complex masses were evaluated. Clinical T1b and T2 tumors accounted for 43.2% and 9.8% of the cases. Overall, 45.9%, 18.8%, and 35.4% of patients underwent open, laparoscopic, and robotic PN, respectively. Intraoperative complications occurred in 15 (3.6%) patients, while postoperative surgical complications were recorded in 76 (18.5%) patients. At multivariable analysis, preoperative hemoglobin (odds ratio [OR]: 0.67; p<0.001) and open (OR: 3.91; p<0.001) versus robotic surgical approach were found to be the only predictors of surgical complications. An estimated glomerular filtration rate drop of >25% from baseline was observed in 30.2% and 17.6% of patients at 1st month and 2 yr after surgery, respectively. Two-year recurrence-free survival was 97.1%; positive surgical margins (hazard ratio [HR]: 3.35; p=0.009), nucleolar grading (HR: 5.61; p<0.001), and tumor stage (HR: 2.62; p=0.05) were associated with recurrence.

CONCLUSIONS

In a large series, PN for complex renal masses was a safe technique with an acceptable rate of perioperative complications and excellent mid-term oncological and functional results.

PATIENT SUMMARY

In this study, we evaluated peri- and postoperative outcomes of patients treated with partial nephrectomy for complex renal masses. Open surgery was associated with higher complications than the robotic approach. Some histological features were found to be associated with disease recurrence.

Management of bilateral Wilms tumours

Wilms tumour is named after Max Wilms. It is an embryonal tumour derived from the metanephros. It is the commonest childhood renal tumour and the third commonest paediatric malignancy. Synchronous bilateral Wilms tumours (BWT) represent 4-7% of all Wilms tumours (WT) and present at a younger age than unilateral Wilms tumours. At least 10% of synchronous BWTs have unfavourable histology, and up to 22% are associated with genitourinary abnormalities, aniridia, WAGR syndrome, Denys-Drash syndrome, hemihypertrophy, or one of the other overgrowth syndromes. The long-term disease-free survival rate for patients with unilateral WT is approaching 90%, and is around 70% for those with metastatic disease. For both synchronous and metachronous Wilms tumours the prognosis is less favourable with reported cure rates approaching 80% in the best centres and lower in resource poor settings. There is potential for a reduced quality of life due to renal insufficiency and the possible need for renal transplantation. The major clinical challenge in BWTs is preservation of functioning renal tissue using nephron-sparing surgical techniques, while achieving cure with minimum therapy-related morbidity. Mortality is generally associated with progressive disease of anaplastic tumours. Chemotherapy followed by nephron-sparing surgery has been able, in most cases, to eradicate the tumour while preserving renal function. Radiotherapy has largely been avoided because of fears of long-term radiation injury to the residual functioning renal mass. Patient selection, appropriate pre- and post-operative chemotherapy and skilled surgical techniques all contribute to excellent outcomes where these are achievable.

Complications Following Nephron-Sparing Surgery for Wilms Tumor

PURPOSE

Because of the increasing use of nephron-sparing surgery (NSS) in bilateral Wilms tumor, we sought to review the early postoperative complications associated with NSS.

METHODS

A retrospective review of patients who underwent NSS at our institution from 2000 to 2017 was performed. For comparison, a cohort of patients who underwent radical nephrectomy (RN) was also reviewed. Early (30-day) postoperative complications and oncologic outcomes were assessed.

RESULTS

Fifty-five patients underwent either bilateral (46) NSS or unilateral (9) NSS owing to prior resection or congenital solitary kidney. Fifty-four patients who underwent unilateral RN were also evaluated. Twenty NSS patients (36.4%) experienced 21 postoperative complications, including prolonged urine leak (9), infection (8), transient renal insufficiency (1), and intussusception (3). Seven RN patients (13.0%) experienced surgical complications, including infection (4) and intussusception (3). Average intraoperative blood loss was significantly greater in NSS as compared to RN (483.51 ± 337.92 mL and 278.15 mL ± 390.25, respectively, p < 0.001), as was the incidence of positive tumor resection margins (20 [36.4%] and 12 [22.2%], respectively, (p = 0.037).

CONCLUSIONS

In our experience, prolonged urine leak, intraoperative blood loss, and positive margins were more frequent in patients undergoing NSS as compared to RN. However, the complications were successfully managed, suggesting that an aggressive approach to NSS in patients with bilateral Wilms tumor is safe and appropriate.

LEVEL OF EVIDENCE

Level III TYPE OF STUDY: Treatment study.

Laparoscopic partial nephrectomy

Laparoscopic partial nephrectomy (LPN) compares favorably to traditional open nephron-sparing surgery (NSS) in terms of oncologic and surgical principles for kidney tumors. Studies have shown the modality to be feasible with similar oncologic efficacy and superior renal functional outcomes compared with laparoscopic radical nephrectomy (LRN) for tumors. The main advantages of LPN include marked improvements in estimated blood loss, decreased surgical site pain, shorter postoperative convalescence, better cosmesis, and nephron preservation. This review article evaluates the literature regarding LPN and discusses the main steps of the operation, the perioperative workup and management, surgical complications, and its role in the surgical management of kidney masses.

The Impact of Surgical Strategy in Robot-assisted Partial Nephrectomy: Is It Beneficial to Treat Anterior Tumours with Transperitoneal Access and Posterior Tumours with Retroperitoneal Access?

Available comparison of transperitoneal robot-assisted partial nephrectomy (tRAPN) and retroperitoneal robot-assisted partial nephrectomy (rRAPN) does not consider tumour's location. The aim of this study was to compare perioperative morbidity, and functional and pathological outcomes after tRAPN and rRAPN, with the specific hypothesis that tRAPN for anterior tumours and rRAPN for posterior tumours might be a beneficial strategy. A large global collaborative dataset of 1169 cT1-2N0M0 patients was used. Propensity score matching, and logistic and linear regression analyses tested the effect of tRAPN versus rRAPN on perioperative outcomes. No differences were observed between rRAPN and tRAPN with respect to complications, operative time, length of stay, ischaemia time, median 1-yr estimated glomerular filtration rate (eGFR), and positive surgical margins (all p>0.05). Median estimated blood loss and postoperative eGFR were 50 versus100ml (p<0.0001) and 82 versus 78ml/min/1.73 m² (p=0.04) after rRAPN and tRAPN, respectively. At interaction tests, no advantage was observed after tRAPN for anterior tumours and rRAPN for posterior tumours with respect to complications, warm ischaemia time, postoperative eGFR, and positive surgical margins (all p>0.05). The techniques of rRAPN and tRAPN offer equivalent perioperative morbidity, and functional and pathological outcomes, regardless of tumour's location. PATIENT SUMMARY: Robot-assisted partial nephrectomy can be performed with a transperitoneal or a retroperitoneal approach regardless of the specific position of the tumour, with equivalent outcomes for the patient.

Oncologic Outcomes of Partial Nephrectomy for Stage T3a Renal Cell Cancer

BACKGROUND

Partial nephrectomy (PN) for clinical stage T3 tumors is controversial. Radical nephrectomy (RN) has been associated with a greater rate of chronic kidney disease, an increased risk of cardiovascular disease, and increased mortality compared with PN. We present our long-term 2-center experience with PN for stage pT3a tumors and compare the oncologic outcomes with those of similar patients treated with RN.

MATERIALS AND METHODS

We reviewed the data from all patients who had undergone nephrectomy for renal cell carcinoma from 1987 to 2015 in 2 medical centers. The study included 134 patients with pathologic stage T3a tumors, of whom 48 and 86 underwent PN and RN, respectively. We compared the 2 groups (PN and RN) using univariate and multivariate analyses.

RESULTS

The tumors of all patients with pathologic stage T3a who had undergone PN had been pathologically upstaged from clinical stage T1 or T2. Univariate and multivariate analyses revealed tumor size was significantly different statistically between the study groups (median, 7.0 cm in RN group vs. 4.0 cm in PN group; P < .001). Surgery type was not a predictor of local recurrence (P = .978), metastatic progression (P = .972), death from renal cancer (P = .626), or death from all causes (P = .974) at the 5-year follow-up point.

CONCLUSION

The results of the present study have shown similar oncologic outcomes between 48 patients with stage pT3a renal cancer who underwent PN and 86 patients who underwent RN. Although PN was not performed on clinical T3a tumors, our findings suggest that PN can also be considered for these tumors and, thus, avoid the long-term complications of RN. However, strict follow-up protocols are mandatory.

Estimated functional renal parenchymal volume predicts the split renal function following renal surgery

PURPOSE

The change in functional renal volume (FRV) has an absolute influence on renal function after nephrectomy (Nx) or nephron-sparing surgery (NSS). In this study, we prospectively examined whether the postoperative renal function following Nx and NSS could be accurately predicted and assessed the reproducibility of our newly developed 3-D image reconstruction system (Kashihara) to measure the FRV.

METHODS

We enrolled 98 patients who underwent Nx and 41 patients who underwent NSS from April 2006 to September 2009 to predict postoperative FRV and renal function. FRV was measured before and after (1 month and 1 year) renal surgery. The postoperative estimated glomerular filtration rate (eGFR) was predicted from the preoperative eGFR calculated from the serum creatinine (sCr) level and the ratio of the postoperative/preoperative FRV. To assess the reproducibility and accuracy of our newly developed 3-dimensional (3-D) image reconstruction system, FRV was measured by five examiners using images obtained by CT (five cases) and MRI (five cases).

RESULTS

Significant correlation was found both for FRV and for renal function between the predictive values and the actually measured values at 1 month and 1 year after surgery, not only in the Nx group, but also in the NSS group. The accuracy and reproducibility could be confirmed both with CT and MRI studies.

CONCLUSIONS

The postoperative FRV and renal function could be predicted preoperatively using a 3-D image reconstructive system, preoperative routine diagnostic imaging, and preoperative sCr level.

Impact of nephrectomy on long-term renal function in non-syndromic children treated for unifocal Wilms tumor

OBJECTIVE

The present study is designed to assess the long-term renal function of children who underwent radical nephrectomy for unifocal Wilms tumor.

METHODS

A single institution retrospective cohort study of non-syndromic children treated with radical nephrectomy for unifocal Wilms tumor between 1995 and 2011 was performed to identify risk factors for decreased glomerular filtration rate (GFR). The primary endpoint was decrease in age-adjusted GFR below normal published ranges. The secondary endpoint was progression to chronic renal insufficiency (CRI).

RESULTS

A total of 55 patients were identified in the cohort. Eight (15%) patients exhibited decreased age-adjusted GFR during the follow-up period, with 2 (4%) progressing to CRI. Increasing time between surgery and the last known GFR follow-up was associated with decreased GFR, with the normal GFR group having median follow-up of 7.32 years versus 11.47 years (p = 0.019) in the decreased GFR group.

CONCLUSIONS

A trend toward decline in GFR was detected with longer follow-up. Longer follow-up may reveal that clinically significant decline in renal function occurs years following nephrectomy among a subset of Wilms tumor survivors, even among those who do not progress to end stage renal disease.

Oncological outcomes and prognostic factors after nephron-sparing surgery in renal cell carcinoma

PURPOSE

To analyse the mid-term oncological results and to asses predictive factors for recurrence and survival after nephron-sparing surgery (NSS) for renal cell carcinoma.

MATERIALS AND METHODS

This is a retrospective study that includes 198 Partial Nephrectomies performed at our institution for malignant renal tumours. Demographic information and pathological characteristics were obtained, and completed statistical analysis was performed to assess predictors for overall survival (OS) and overall recurrence in our sample.

RESULTS

The presence of positive surgical margins (PSM) in the surgical specimen was reported in 13.6 %. At a median of follow-up of 56.1 months, the non-adjusted cancer-specific mortality, DSS and OS were 100, and 93.4 %, respectively. In the bivariate analysis regarding predictive factors for recurrence, bilaterality and NSS indication (elective or imperative) were statistically significant (p = 0.03 and p = 0.05 respectively). On multivariate analysis only bilaterality was a significant predictor of recurrence (p = 0.03), while high Fuhrman grade was for survival (p = 0.006).

CONCLUSION

Our data suggest that patients with bilateral tumours have a higher incidence of local recurrence. Regarding overall survival, our data showed more risk of death at 5 years in those patients with high Fuhrman grade. No differences were found among PSM and negative surgical margins patients regarding oncological outcomes.

Outcome of kidney function after ischaemic and zero-ischaemic laparoscopic and open nephron-sparing surgery for renal cell cancer

Background

Nephron-sparing surgery (NSS) remains gold standard for the treatment of localised renal cell cancer (RCC), even in case of a normal contralateral kidney. Compared to radical nephrectomy, kidney failure and cardiovascular events are less frequent with NSS. However, the effects of different surgical approaches and of zero ischaemia on the postoperative reduction in renal function remain controversial.

We aimed to investigate the relative short- and long-term changes in estimated glomerular filtration rate (eGFR) after ischaemic or zero-ischaemic open (ONSS) and laparoscopic NSS (LNSS) for RCC, and to analyse prognostic factors for postoperative acute kidney injury (AKI) and chronic kidney disease (CKD) stage ≥3.

Methods

Data of 444 patients (211 LNSS, 233 ONSS), including 57 zero-ischaemic cases, were retrospectively analysed. Multiple regression models were used to predict relative changes in renal function. Natural cubic splines were used to demonstrate the association between ischaemia time (IT) and relative changes in renal function.

Results

IT was identified as significant risk factor for short-term relative changes in eGFR (ß = − 0.27) and development of AKI (OR, 1.02), but no effect was found on long-term relative changes in eGFR. Natural cubic splines revealed that IT had a greater effect on patients with baseline eGFR categories ≥G3 concerning short-term decrease in renal function and development of AKI. Unlike LNSS, ONSS was significantly associated with short-term decrease in renal function (ß = − 13.48) and development of AKI (OR, 3.87). Tumour diameter was associated with long-term decrease in renal function (ß = − 1.76), whereas baseline eGFR was a prognostic factor for both short- (ß = − 0.20) and long-term (ß = − 0.29) relative changes in eGFR and the development of CKD stage ≥3 (OR, 0.89).

Conclusions

IT is a significant risk factor for AKI. The short-term effect of IT is not always linear, and the impact also depends on baseline eGFR. Unlike LNSS, ONSS is associated with the development of AKI. Our findings are helpful for surgical planning, and suggest either the application of a clampless NSS technique or at least the shortest possible IT to reduce the risk of short-time impairment of the renal function, which might prevent AKI, particularly regarding patients with baseline eGFR category ≥G3.