Assessing the perioperative outcomes of abdominal drain omission after robot-assisted partial nephrectomy

The study aimed to evaluate the impact of abdominal drain placement (vs. omission) on perioperative outcomes of robot-assisted partial nephrectomy (RAPN), focusing on complications, time to canalization, deambulation, and pain management. A prospectively-maintained institutional database was queried to get data of patients who underwent RAPN for renal masses between January 2018 and May 2023 at our Institution. Baseline, surgical, and postoperative data were collected. Retrieved patients were stratified based upon placement of abdominal drain (Y/N). Descriptive analyses comparing the two groups were conducted as appropriate.77 After adjusting for potential confounders, a logistic regression analysis was conducted to evaluate significant predictors of any grade and "major" complications. 342 patients were included: 192 patients in the "drain group" versus 150 patients in the "no-drain" group. Renal masses were larger (p < 0.001) and at higher complexity (RENAL score, p = 0.01), in the drain group. Procedures in the drain group had statistically significantly longer operative time, ischemia time, and higher blood loss (all p-values < 0.001). The urinary collecting system was more likely involved compared to the no-drain group (p = 0.01). At multivariate analysis, abdominal drainage was not a significant predictor of any grade (OR 0.79, 95%CI 0.33-1.87) and major postoperative complications (OR 3.62, 95%CI 0.53-9.68). Patients in the drain group experienced a statistically significantly higher hemoglobin drop (p < 0.01). Moreover, they exhibited statistically significant higher paracetamol consumption (p < 0.001) and need for additional opioids (p = 0.02). In summary, the study results suggest the safety of omitting drain placement and remark on the need for personalized decision-making, which considers patient and procedural factors.

Robot-assisted excision of hemangioma of the right renal vein

Hemangiomas, benign vascular masses, occasionally occur in the kidneys, presenting as rare, small, unilateral, and solitary growths. Venous hemangiomas, a renal subtype, are atypical. While clinically nonspecific, they are typically asymptomatic and may be incidentally discovered during unrelated clinical workups. Diagnosing renal hemangioma preoperatively is challenging due to rarity, lacking standard radiographic criteria, and poor differentiation from aggressive renal neoplasms on contrast-enhanced imaging. These tumors commonly follow a benign course, with no documented recurrence. This video article showcases the robot-assisted excision of a renal vein hemangioma, addressing the expertise needed in managing this uncommon condition robotically.

Postoperative outcomes of transperitoneal versus retroperitoneal robotic partial nephrectomy: a propensity-score matched comparison focused on patient mobilization, return to bowel function, and pain

Literature meta-analyses comparing transperitoneal versus retroperitoneal approach to robotic partial nephrectomy (RPN) suggested some advantages favoring retroperitoneoscopy. Unfortunately, patient-centered data about mobilization, canalization, pain, and use of painkillers remained anecdotally reported. The present analysis aimed to compare transperitoneal versus retroperitoneal RPN focusing on such outcomes. Study data including baseline variables, perioperative, and postoperative outcomes of interest were retrieved from prospectively maintained institutional database (Jan 2018-May 2023) and compared between treatment groups (transperitoneal versus retroperitoneal). Propensity score matching was performed using the STATA command psmatch2 considering age, sex, body mass index, previous abdominal surgery, RENAL score, tumor size and location, and cT stage. The logit of propensity score was used for matching, with a 1:1 nearest neighbor algorithm, without replacement (caliper of 0.001). A total of 442 patients were included in the unmatched analysis: 330 underwent transperitoneal RPN 112 retroperitoneal RPN. After propensity score, 98 patients who underwent retroperitoneal RPN were matched with 98 patients who underwent transperitoneal RPN. Matched cohorts had comparable patients' demographics and tumor features. We found similarity between the two laparoscopic accesses in all outcomes but in blood loss, which favored retroperitoneoscopic RPN (median 150 (IQR 100-300) versus 100 (IQR 0-100) ml, p = 0.03). No differences were found in terms of time to mobilization with ambulation, return to complete bowel function, postoperative pain, but higher painkillers consumption was reported after transperitoneal RPN (p < 0.004). The present study compared the transperitoneal versus the retroperitoneal approach to RPN, confirming the similarity between the two approaches in all perioperative outcomes. Based on our findings, the choice of the surgical approach to RPN may remain something that the surgeon decides.

Irreversible electroporation: Beyond the limits of tumor ablation

Irreversible Electroporation (IRE) is a non-thermal tumor ablation technique. High-voltage electrical pulses are applied between pairs of electrodes inserted around and/or inside a tumor. The generated electric current induces the creation of nanopores in the cell membrane, triggering apoptosis. As a result, IRE can be safely used in areas near delicate vascular structures where other thermal ablation methods are contraindicated. Currently, IRE has demonstrated to be a successful ablation technique for pancreatic, renal, and liver tumors and is widely used as a focal therapeutic option for prostate cancer. The need for specific anesthetic management and accurate parallel placement of multiple electrodes entails a high level of complexity and great expertise from the interventional team is required. Nevertheless, IRE is a very promising technique with a remarkable systemic immunological capability and may impact on distant metastases (abscopal effect).

An Overview of Renal Cell Carcinoma Hallmarks, Drug Resistance, and Adjuvant Therapies

Renal neoplasms are highlighted as one of the 10 most common types of cancer. Renal cell carcinoma (RCC) is the most common type of renal cancer, considered the seventh most common type of cancer in the Western world. The most frequently altered genes described as altered are VHL, PBRM1, SETD2, KDM5C, PTEN, BAP1, mTOR, TP53, TCEB1 (ELOC), SMARCA4, ARID1A, and PIK3CA. RCC therapies can be classified in three groups: monoclonal antibodies, tyrosine kinase inhibitors, and mTOR inhibitors. Besides, there are targeted agents to treat RCC. However, frequently patients present side effects and resistance. Even though many multidrug resistance mechanisms already have been reported to RCC, studies focused on revealing new biomarkers as well as more effective antitumor therapies with no or low side effects are very important. Some studies reported that natural products, such as honey, epigallocatechin-3-gallate (EGCG), curcumin, resveratrol, and englerin A showed antitumor activity against RCC. Moreover, nanoscience is another strategy to improve RCC treatment and reduce the side effects due to the improvement in pharmacokinetics and reduction of toxicities of chemotherapies. Taking this into account, we conducted a systemic review of recent research findings on RCC hallmarks, drug resistance, and adjuvant therapies. In conclusion, a range of studies reported that RCC is characterized by high incidence and increased mortality rates because of the development of resistance to standard therapies. Given the importance of improving RCC treatment and reducing adverse effects, nanoscience and natural products can be included in therapeutic strategies.

Robotic approach with neoadjuvant chemotherapy in adult Wilms' tumor: A feasibility study report and a systematic review of the literature

Objective

The incidence of Wilms' tumor (WT) among adult individuals accounts for less than 1% of kidney cancer cases, with a prognosis usually less favorable when compared to younger individuals and an overall survival rate of 70% for the adult patients versus 90% for the pediatric cases. The diagnosis and treatment of WT are complex in the preoperative setting; neoadjuvant chemotherapy (NAC) or robotic surgery has rarely been described. This study aimed to review the literature of robotic surgery in WT and report the first adult WT management using both NAC and robotic strategy.

Methods

We reported a case of WT managed in a multidisciplinary setting. Furthermore, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations, a systematic review of the literature until August 2020 of WT treated with a robotic approach was carried out.

Results

A 33-year-old female had a diagnosis of WT. She was scheduled to NAC, and according to the clinical and radiological response to a robotic radical nephrectomy with aortic lymph nodes dissection, she was managed with no intraoperative rupture, a favorable surgical outcome, and a follow-up of 25 months, which did not show any recurrence. The systematic review identified a total number of 230 cases of minimally invasive surgery reported in the literature for WT. Of these, approximately 15 patients were carried out using robotic surgery in adolescents while none in adults. Moreover, NAC has not been administered before minimally invasive surgery in adults up until now.

Conclusion

WT is a rare condition in adults with only a few cases treated with either NAC or minimally invasive approach so far. The advantage of NAC followed by the robotic approach could lead to favorable outcomes in this complex scenario. Notwithstanding, additional cases of adult WT need to be identified and investigated to improve the oncological outcome.

Randomized Clinical Trial Comparing On-clamp Versus Off-clamp Laparoscopic Partial Nephrectomy for Small Renal Masses (CLOCK II Laparoscopic Study): A Intention-to-treat Analysis of Perioperative Outcomes

Background

Recent randomized trials (RCTs) in the field of robotic partial nephrectomy (PN) showed no significant differences in perioperative outcomes between the off- and on-clamp approaches.

Objective

To compare the perioperative outcomes of on- versus off-clamp pure laparoscopic PN (LPN).

Design setting and participants

A multi-institutional analysis of the on- versus off-clamp approach during LPN in the setting of an RCT (CLOCK II trial; ClinicalTrials.gov NCT02287987) was performed.

Intervention

Off- versus on-clamp LPN.

Outcome measurements and statistical analysis

Baseline patient and tumor variables, and peri- and postoperative data were collected. Randomized allocation with a 1:1 ratio was assigned. Surgical strategy for managing the renal pedicle was dictated by the study protocol. In the off-clamp arm, the renal artery had to remain unclamped for the duration of the whole procedure. Reporting the intention-to-treat analysis is the purpose of the study.

Results and limitations

The study recruited 249 patients. Of them, 123 and 126 were randomized and allocated into the on- and off-clamp treatment groups, respectively. Treatment groups were comparable at baseline after randomization with respect to patients' demographics, comorbidities, renal function, and tumor size and complexity. A univariable analysis found no differences in the perioperative outcomes between the groups, including median (interquartile range) estimated blood loss (150 [100-200] vs 150 [100-250] ml, p = 0.2), grade ≥2 complication rate as classified according to the Clavien-Dindo system (5.7% vs 4.8%, p = 0.6), and positive surgical margin rate (8.2% vs 3.5% for the on- vs off-clamp group, p = 0.1). No differences were found in terms of the 1st (81.3 [66.7-94.3] vs 85.3 [71.0-97.7] ml/min, p = 0.2) and 5th postoperative days estimated glomerular filtration rate (83.3 [70.5-93.7] vs 83.4 [68.6-139.3] ml/min, p = 0.2). A multivariable analysis found each +1 increase in RENAL score corresponded to an increase in the protection from the occurrence of complications (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.54-0.97, p = 0.034), while each +1 cm increase in tumor size corresponded to an increase in the risk of blood transfusion (OR 1.39, 95% CI 1.14-1.70, p = 0.001).

Conclusions

In the setting of an RCT, no differences were found in the perioperative and early functional outcomes between on- and off-clamp LPN.

Patient summary

In this study, we investigated, by means of a randomized trial, whether avoiding the clamping of renal artery during laparoscopic resection of renal mass is able to translate into benefits. We found no differences in terms of safety, efficacy, and renal function from the standard approach, which includes arterial clamping.

Surgical outcomes of robot-assisted laparoscopic partial nephrectomy for cystic renal cell carcinoma

To compare the surgical outcomes of robot-assisted partial nephrectomy (RAPN) between patients with cystic renal cell carcinoma (cRCC) and those with solid RCC (sRCC). We retrospectively analyzed 1065 patients who underwent RAPN between 2013 and 2020 for a pathological diagnosis of RCC. Patients were divided into two groups: cRCC and sRCC. cRCC was diagnosed according to the Bosniak classification system. To minimize selection bias between the two groups, patient variables (patient characteristics) and tumor factors (such as size and complexity) were adjusted using 1:1 propensity score matching. Of the 1065 patients, 94 (9%) were diagnosed with cRCC. Bosniak categories of IIF, III, and IV were noted in 4 (4.2%), 31 (33%), and 59 (63%) patients, respectively. After matching, 83 patients each were assigned to the cRCC and sRCC groups. The operation time in cRCC tended to be longer than in sRCC but not significantly different (164 vs. 150 min, P = 0.0767). Other surgical outcomes, such as change in estimated glomerular filtration rate ( - 5.2 vs.  - 7.2%, P = 0.1577), perioperative complications (14.5 vs. 15.7%, P = 0.9225), estimated blood loss (62 vs. 58 mL, P = 0.5613), or negative surgical margin status (100 vs 99%, P = 0.236), were not significantly different between the two groups. During the follow-up period of about 2 years, one and two patients showed recurrence in the cRCC and sRCC groups, respectively. The surgical outcomes of RAPN were similar between cRCC and sRCC, demonstrating the feasibility of RAPN for cRCC.

Total renal volume and renal function after radical nephrectomy in renal neoplasm

INTRODUCTION

The reduction of renal mass after radical nephrectomy (RN) for renal neoplasm, could be associated with compensatory hypertrophy of the contralateral kidney. The capacity of compensation will determine the renal function (RF) evolution. Measuring of total renal volume (TRV) of the remaining kidney pre and post RN can help assess the RF evolution.

OBJECTIVES

To determine the correlation between TRV pre and post nephrectomy (a year of follow-up) with RF.

MATERIALS AND METHODS

A retrospective cohort study was carried out in 47 patients who had undergone RN from 2014 to 2018, due to renal cell carcinoma (confirmed by histopathology). The TRV was calculated, pre and post (a year of follow-up) RN, using ellipsoid formula equation, which were compared with clinical and analytical data. The results were analyzed by multivariate linear logistic models.

RESULTS

The median age at the time of RN was 70 years old (range, 40-88 years). Most of them were men, 66%. The estimated glomerular filtration rate (eGFR) pre and post nephrectomy was 78 (40-100) and 53.3ml/min/m² (30-90) respectively (p=0.01). The TRV pre and post-nephrectomy was 168.2ml (100.4-257.2) and 187.8ml (115.5-273.1) respectively (p=0.001). The pre-nephrectomy eGFR (β=0.62; p=0.034) and the TRV (β=1.08; p<0.0001) were positively correlated with the post-nephrectomy TRV, while the eGFR at year of follow-up was correlated negatively (β=-1.18; p=0.047).

CONCLUSIONS

The measurement of pre and post nephrectomy TRV can help to predict renal function evolution at a year of follow-up.

Three-dimensional Reconstruction of Renal Vascular Tumor Anatomy to facilitate accurate preoperative planning of partial nephrectomy

Objectives

To evaluate the role of three-dimensional (3D) reconstruction tumors and vessels of the kidneys in aiding the preoperative planning of partial nephrectomy.

Materials and methods

Patients with renal tumors to be treated with partial nephrectomy were included. Each patient underwent a preoperative computed tomography (CT) survey, and the reconstruction of each patient's 3D arteriography and 3D surface-rendered tumor was performed based on the CT images for preoperative surgical planning.

Results

A total of 6 patients, three with tumors of the right kidney and three with tumors of the left kidney, were enrolled in the study. The patients' mean age was 49.33 ± 4.03 years (range: 45-57 years), and their mean tumor size was 4.4 ± 1.84 cm (range: 2.2-6.8 cm). Four underwent robot-assisted laparoscopic partial nephrectomies, one underwent a traditional laparoscopic partial nephrectomy, and one underwent a radical nephrectomy through laparotomy. Their average postoperative hospital stay was 6.7 days (range: 3-10 days). No intraoperative or postoperative complications were noted. The renal function was preserved in all the patients, and none of the patients exhibited evidence of local recurrence during more than 6 years of follow-up.

Conclusions

3D arteriography fused with 3D surface-rendered tumor image navigation facilitates precise preoperative planning.

Robotic-Assisted Versus Conventional Open Partial Nephrectomy (Robocop): A Propensity Score-Matched Analysis of 249 Patients

OBJECTIVES

The objective of this study was to compare open partial nephrectomy (OPN) and robotic-assisted PN (RAPN) based on a propensity score-matched sample and to test the Comprehensive Complication Index (CCI) as an end point for complications.

METHODS

Patients undergoing PN from 2010 to 2018 at a university care center were included. OPN and RAPN cases were matched in a 2:1 ratio using propensity score-matching with age, gender, BMI, RENAL score, and tumor size as confounders. The primary end point was complications measured with the CCI as continuous score (0-100, 100 indicating death).

RESULTS

Data of 570 patients were available. After matching, both cohorts (OPN = 166; RAPN = 83) showed no baseline differences. For the primary end point, CCI, RAPN was superior (RAPN 2.6 ± 7.9 vs. OPN 8.7 ± 13.9; p < 0.001). Additionally, RAPN was superior for length of stay (RAPN 6.5 ± 4.0 vs. OPN 7.4 ± 3.5 days; p < 0.001), hemoglobin drop (RAPN 2.8 ± 1.4 vs. OPN 3.8 ± 1.6 g/dL; p < 0.001), and drop of glomerular filtration rate (RAPN 11.4 ± 14.2 vs. OPN 19.5 ± 14.3 mL/min; p < 0.001). OPN had shorter operating times (RAPN 157 ± 43 vs. OPN 143 ± 45 min; p = 0.014) and less ischemia (RAPN 13% vs. OPN 28%; p = 0.016).

CONCLUSIONS

RAPN provides superior short-term results regarding overall complications without compromising renal function for small and less complex tumors. However, OPN remains an important option for more complex and larger tumors.

Contrast-enhanced ultrasound (CEUS) imaging for active surveillance of small renal masses

PURPOSE

To assess the safety and efficacy of contrast-enhanced ultrasound (CEUS) imaging for monitoring small (< 4 cm) renal masses (SRM) in patients undergoing active surveillance (AS).

METHODS

We retrospectively selected all consecutive patients with SRMs who underwent AS for at least 6 months at our Institution between January 2014 and December 2018. CEUS imaging was performed by two experienced genitourinary radiologists at established time points. The accuracy of CEUS for monitoring SRM size was compared with that of CT scan. For solid SRMs, four enhancement patterns (EP) were recorded. Radiological progression was defined as SRM growth rate ≥ 5 mm/year.

RESULTS

Overall, 158/1049 (15.1%) patients with SRMs underwent AS. At a median follow-up of 25 months (IQR 13-39), no patient died due to renal cell carcinoma (RCC). No patients experienced CEUS-related adverse events. There was a large variability in the pattern of growth of SRMs (overall median growth rate: 0.40 mm/year), with 9.5% of SRMs showing radiological progression. The median SRM size was comparable between CEUS and CT scan examinations at all time points. The vast majority (92.7%) of SRMs did not show a change in their EP over time; and there was no association between the SRM's EP and radiological progression or SRM size. Overall, 43 (27.2%) patients underwent delayed intervention (DI); median SRM size, and median growth rate were significantly higher in these patients as compared to those continuing AS.

CONCLUSION

In experienced hands, CEUS is a safe and effective strategy for active monitoring of SRMs in well-selected patients undergoing AS.

Automated segmentation of kidney and renal mass and automated detection of renal mass in CT urography using 3D U-Net-based deep convolutional neural network

OBJECTIVES

To develop a 3D U-Net-based deep learning model for automated segmentation of kidney and renal mass, and detection of renal mass in corticomedullary phase of computed tomography urography (CTU).

METHODS

Data on 882 kidneys obtained from CTU data of 441 patients with renal mass were used to learn and evaluate the deep learning model. The CTU data of 35 patients with small renal tumors (diameter ≤ 1.5 cm) were used for additional testing. The ground truth data for the kidney, renal tumor, and cyst were manually annotated on corticomedullary phase images of CTU. The proposed segmentation model for kidney and renal mass was constructed based on a 3D U-Net. The segmentation accuracy was evaluated through the Dice similarity coefficient (DSC). The volume of the maximum 3D volume of interest of renal tumor and cyst in the predicted segmentation by the model was used as an identification indicator, while the detection performance of the model was evaluated by the area under the receiver operation characteristic curve.

RESULTS

The proposed model showed a high accuracy in segmentation of kidney and renal tumor, with average DSC of 0.973 and 0.844, respectively. It performed moderately in the renal cyst segmentation, with an average DSC of 0.536 in the test set. Also, this model showed good performance in detecting renal tumor and cyst.

CONCLUSIONS

The proposed automated segmentation and detection model based on 3D U-Net shows promising results for the segmentation of kidney and renal tumor, and the detection of renal tumor and cyst.

KEY POINTS

• The segmentation model based on 3D U-Net showed high accuracy in segmentation of kidney and renal neoplasm, and good detection performance of renal neoplasm and cyst in corticomedullary phase of CTU. • The segmentation model based on 3D U-Net is a fully automated aided diagnostic tool that could be used to reduce the workload of radiologists and improve the accuracy of diagnosis. • The segmentation model based on 3D U-Net would be helpful to provide quantitative information for diagnosis, treatment, surgical planning, etc.

A rare case of a cystic renal mass with heterotopic ossification and a mini literature review

INTRODUCTION

It is a challenge to make accurate pre-surgical diagnosis for renal tumors. This study is to report the findings, management, and outcome of one rare case of ossification in a cystic renal mass. We present and discuss the pathological characteristics, radiologic features, and treatment alternatives of the patient.

PATIENTS AND METHODS

A 38 years old female patient had intermittent epigastric pain and microscopic hematuria for two months. Computerized tomography (CT) scan and Magnetic Resonance imaging (MRI) showed a mass with rough edge and dense calcification in the upper pole of the right kidney and normal left kidney. Pre-operative diagnosis is cystic nephroma or cystic renal mass (Bosniak III type, Bosniak renal cyst classification). GFR was within normal limits for age and no other significant laboratory aberrations were noted. Patient underwent a right retroperitoneal laparoscopic partial nephrectomy (margin status was negative). A mini literature review was performed to highlight the principals of diagnosis and treatment of cystic renal mass with heterotopic ossification.

RESULTS

The entire renal mass was successfully removed from upper pole of the right kidney by laparoscopic nephron sparing surgery. The size of renal mass is 38×35×30 mm3 with thick and hard capsular wall. The cystic cavity contains yellow lipid-like substances without stone. Histological examination revealed renal cyst in which the cyst wall reveals fibrosis and no obvious lining epithelium. The additional unique feature includes the presence of dense calcification and ossification in the renal mass. Localization tissue of yellow bone marrow was detected. No complications occurred in 9 months after surgery during follow-up.

CONCLUSIONS

Cystic renal mass with heterotopic ossification is a rare case of non-malignant renal tumor. Whether surgery is needed depends to whether patients have symptoms. For symptom renal tumors, laparoscopic nephron sparing surgical procedure is recommended. Furthermore, complete surgical resection of the lesion is needed when the mass is suspected to be malignant. An accurate histologic diagnosis is key in its diagnosis.

Development of a Novel Risk Score to Select the Optimal Candidate for Cytoreductive Nephrectomy Among Patients with Metastatic Renal Cell Carcinoma. Results from a Multi-institutional Registry (REMARCC)

BACKGROUND

Selection of patients for upfront cytoreductive nephrectomy (CN) in metastatic renal cell carcinoma (mRCC) has to be improved.

OBJECTIVE

To evaluate a new scoring system for the prediction of overall mortality (OM) in mRCC patients undergoing CN.

DESIGN, SETTING, AND PARTICIPANTS

We identified a total of 519 patients with synchronous mRCC undergoing CN between 2005 and 2019 from a multi-institutional registry (Registry for Metastatic RCC [REMARCC]).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional hazard regression was used to test the main predictors of OM. Restricted mean survival time was estimated as a measure of the average overall survival time up to 36 mo of follow-up. The concordance index (C-index) was used to determine the model's discrimination. Decision curve analyses were used to compare the net benefit from the REMARCC model with International mRCC Database Consortium (IMDC) or Memorial Sloan Kettering Cancer Center (MSKCC) risk scores.

RESULTS AND LIMITATIONS

The median follow-up period was 18 mo (interquartile range: 5.9-39.7). Our models showed lower mortality rates in obese patients (p = 0.007). Higher OM rates were recorded in those with bone (p = 0.010), liver (p = 0.002), and lung metastases (p < 0.001). Those with poor performance status (<80%) and those with more than three metastases had also higher OM rates (p = 0.026 and 0.040, respectively). The C-index of the REMARCC model was higher than that of the MSKCC and IMDC models (66.4% vs 60.4% vs 60.3%). After stratification, 113 (22.0%) patients were classified to have a favorable (no risk factors), 202 (39.5%) an intermediate (one or two risk factors), and 197 (38.5%) a poor (more than two risk factors) prognosis. Moreover, 72 (17.2%) and 51 (13.9%) patients classified as having an intermediate and a poor prognosis according to MSKCC and IMDC categories, respectively, would be reclassified as having a good prognosis according to the REMARCC score.

CONCLUSIONS

Our findings confirm the relevance of tumor and patient features for the risk stratification of mRCC patients and clinical decision-making regarding CN. Further prospective external validations are required for the scoring system proposed herein.

PATIENT SUMMARY

Current stratification systems for selecting patients for kidney removal when metastatic disease is shown are controversial. We suggest a system that includes tumor and patient features besides the systems already in use, which are based on blood tests.

Open partial nephrectomy: current review

Partial nephrectomy (PN) is increasingly considered the gold standard treatment for localized renal cell carcinomas (RCCs) where technically feasible. The advantage of nephron-sparing surgery lies in preservation of parenchyma and hence renal function. However, this advantage is counterbalanced with increased surgical risk. In recent years with the popularization of minimally invasive partial nephrectomy (laparoscopic and robotic), the contemporary role of open PN (OPN) has changed. OPN has several advantages, particularly in complex patients such as those with a solitary kidney, multi-focal tumors, and significant surgical history, as well as providing improved application of renoprotective measures. As such, it is a technique that remains relevant in current urology practice. In this article we discuss the evidence, indications, operative considerations and surgical technique, along with the role of OPN in contemporary nephron-sparing surgery.

Reevaluation of metanephric stromal tumor two decades after it was named: A narrative review

OBJECTIVE

The aim of this narrative review is to provide an overview and update of metanephric stromal tumor (MST).

MATERIALS AND METHODS

All English language studies published from January 1, 2000 to December 31, 2019 in PubMed, EBSCO, Elsevier ScienceDirect, Springer Link and Taylor & Francis databases were searched with the search terms "metanephric stromal tumor" for this review.

RESULTS

Seventeen eligible case reports representing 47 patients according to inclusion and exclusion criteria were included in this study. The average age of the patients was under 4 years (range from 2 d to 56 y) and over half of the cases (52.1%, 25/47) are were diagnosed as MST by accident or during examinations for other diseases. Morphologically, tumor specimens of almost all cases presented concentric "onion-skin cuffing" or characteristic collarettes around renal tubules under low power. There were 79.2% (18/25) of patients exhibited BRAF V600E mutations. Immunohistochemistry (IHC) is characterized by CD34 (+), Vimentin (+), Desmin (-), S-100 (-), SMA (-). Most patients underwent surgeries, and no metastasis or recurrence was found except for one case.

CONCLUSION

MST is a rare benign pediatric renal tumor with surgical treatment as the first choice. CT examinations and ultrasonography are two widely accepted techniques for the diagnosis of MST. Percutaneous renal biopsy (PRB) is an effective and accurate way of preoperative diagnosis, however, it is not recommended for children under 10 years or with a cystic mass in CT images. The relationship between BRAF V600E mutations and mild clinical manifestations of MST is in need of further verification by biological experiments and clinical studies.

Adrenal-Renal Fusion with Adrenal Cortical Adenoma and Ectopic Adrenal Tissue, Presenting as Suspected Renal Mass: A Case Report

Adrenal-renal fusion with adrenal cortical adenoma is a rare anomaly with only a few cases described in the literature. Imaging-based identification of this anomaly remains a diagnostic challenge, making it difficult to differentiate upper pole renal malignancy from adrenal cortical adenoma. We describe a case of a 62-year-old woman with an upper pole cystic renal mass on imaging, who underwent robotic partial nephrectomy. Intraoperatively the renal mass was found to be an adrenal-renal fusion anomaly, with ectopic adrenal tissue. Adrenal-renal infusion of an adrenal cortical adenoma was confirmed on final pathology. Due to lack of imaging-based diagnosis, this condition should be considered in the differential for upper pole renal masses.

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

BACKGROUND

Chronic kidney disease (CKD) is a severe long-term complication after partial nephrectomy (PN). Clinical and scientific focus lies on patients with impaired renal function at the time of surgery. Little data is available on patients with normal preoperative renal function (NPRF).

PATIENTS AND METHODS

Patients who underwent PN with a preoperative estimated glomular filtration rate > 60 mL/min/1.73m² were retrospectively examined at 8 European urologic centers. The occurrence of new onset CKD ≥ stage III after surgery (sCKD) was defined as the primary endpoint. Group comparisons and risk correlations were determined. Based on this data, a risk stratification model for sCKD was developed.

RESULTS

Of the 1315 patients with NPRF included, 249 (18.9%) developed sCKD after a median follow-up of 44 months (range, 6-255 months). Pair analysis and univariable regression revealed age, arterial hypertension, American Society of Anesthesiologists score, tumor stage, surgical approach, intraoperative blood loss, perioperative blood transfusions and preoperative CKD stage as predictors for sCKD development. Multivariate analysis confirmed perioperative blood transfusion (hazard ratio [HR], 2.96; P ≤ .0001), age (≥ 55 years; HR, 2.60; P = .0002), tumor stage (> pT1; HR, 2.15; P = .025), and preoperative CKD stage (stage II vs. I; HR, 3.85; P ≤ .0001) as independent risk factors. A model that stratified patient risk for new onset CKD was highly significant (P < .0001).

CONCLUSION

Every fifth patient with NPRF developed sCKD following PN. Elderly patients with higher tumor stage and who require blood transfusion appear to be at increased risk. Based on our risk stratification, patients with ≥ 2 risk factors are candidates for an early, nephrologic follow-up.

[Partial nephrectomy in mesorrenal tumors greater than 4 cm: 15 years of experience.]

OBJECTIVES

Mesorenal tumors (those located in the renal middle line or between both poles) are complex cases for partial nephrectomy (PN). Our objective is to evaluate oncological and perioperative results of PN in these patients with mesorenal tumors greater than 4 cm, mesophytic or endophytic.

METHODS

A review of the medical records of patients with tumors with these characteristics operated between January 2016 and June 2016 was performed.

RESULTS

36 cases were included. The mean age was 54.2 years (24-79) with 12 cases of male gender. Mean surgical time: 139 minutes (120-280); 30 cases with complete clamping with mean ischemia of 19 minutes (10-90) and 6 compression of the parenchyma. Mean estimated bleeding: 280 ml (100-900). Mean tumor diameter: 4.3 cm (4.0 to 7.6). Preoperative and postoperative mean glomerular filtration rate 89 ml/min and 76 ml/min (p=0.32) respectively. Median length of stay: 3.8 days (2-21). There were 2 (6.5%) complications (II and IIIb). One case (3.3%) presented positive margin. One patient died due to progression at 14 months. With a median follow-up of 52.1 months (10-168) no recurrences were observed.

CONCLUSIONS

We consider that mesorenal tumors, with significant penetration within the renal parenchyma and greater than 4 cm, PN presents both oncological and satisfactory results.

Low Rate of Cancer Events After Partial Nephrectomy for Renal Cell Carcinoma: Clinicopathologic Analysis of 1994 Cases with Emphasis on Definition of "Recurrence"

BACKGROUND

Systematic pathology reviews in patients who experienced a clinical "recurrence" after partial nephrectomy for renal cell carcinoma (RCC) are anecdotal; therefore, definitions of "recurrence" varies considerably. We aimed to better define local recurrence by re-evaluation of surgical specimens of patients who experienced "recurrences" after partial nephrectomy at our institution.

MATERIALS AND METHODS

Retrospective analysis of our institutional partial nephrectomy data set was performed. Patients who were clinically diagnosed with a local recurrence during the oncological follow-up after primary intervention for RCC were considered (January 2007 to December 2017, institutional review board number 5065, 15-1593). Re-evaluation of specimens coming from either primary treatment or management of the diagnosed recurrent disease was performed by 2 dedicated urologic pathologists. According to the findings of the pathology review, patients were assigned to 3 groups of disease event: (1) local recurrence of RCC; (2) new occurrence of RCC; and (3) micrometastatic RCC. Patient demographic characteristics, tumor pathological characteristics, oncological outcomes, disease treatment, and follow-up were reported for each patient. Cancer-specific survival was compared using the Kaplan-Meier method.

RESULTS

Of 1994 cases recorded in the institutional database, data on 30 patients who were clinically diagnosed with a local recurrence were extracted. After pathology review, 9 patients were found who truly developed a local recurrence (group 1). Positive surgical margin status was poorly related to the likelihood of a true local recurrence as defined herein. Twelve patients were assessed with a new occurrence of RCC (group 2). Nine were diagnosed with micrometastatic RCC (group 3). With comparable follow-up lengths among the groups (39 [interquartile range (IQR), 32-45] versus 51.5 [IQR, 35-90.5] versus 42 [IQR, 13-65], group 1 versus 2 versus 3, respectively; P = .4), patients classified in group 1 and 3 had comparable cancer-specific survival (P = .5). Conversely, patients in group 2 were less likely to die of disease compared with group 1 and 3 patients (P = .02).

CONCLUSION

Careful pathologic classification of RCC disease events after partial nephrectomy has important prognostic implications and allows more precise study of the clinical significance of margin status.

Novel use of the AngioVac system

The Vortex Medical AngioVac Cannula was employed in a 71-year-old man with a renal neoplasm with occlusion of the inferior vena cava and involvement of the right atrial cavity. Due to the presence of diffuse metastases, surgery was not indicated, and the AngioVac system was employed to remove the free-floating mobile atrial mass, thus minimizing the risk of pulmonary embolism and as a bioptic tool to allow a correct histological diagnosis. This novel use of this system may be advantageous in other similar cases.

Imaging of Unusual Renal Tumors

PURPOSE OF REVIEW

Renal masses are a wide entity and a common finding in clinical practice. Detection of these masses has increased in the last years, yet mortality rates have slightly decreased.

RECENT FINDINGS

According to the World Health Organization classification, there are 8 types, 51 subtypes, and a lot more subsequent subclassifications of renal tumors. Histopathological analysis should always be assessed for final diagnosis of theses tumors. However, imaging can be an important diagnostic guidance. The most common diagnoses of renal tumor are clear cell carcinoma, papillary renal cell carcinoma, angiomyolipoma, and transitional cell carcinoma. Nonetheless, a considerable variety of particular tumors can arise from the kidney, challenging the expertise of radiologists and urologists on this subject. The awareness of these unusual entities is vital for professionals working at a complex medical facility with greater volume of patients. We hereby present uncommon renal tumors and its pathological and radiological features.

Development and Internal Validation of a Nomogram for Predicting Renal Function after Partial Nephrectomy

Loss of renal function can be a clinically impactful event after partial nephrectomy (PN). We aimed to create a model to predict loss of renal function in patients undergoing PN. Data for 1897 consecutive patients who underwent PN with warm ischemia between 2008 and 2017 were extracted from our institutional database. Loss of renal function was defined as upstaging of chronic kidney disease in terms of the estimated glomerular filtration rate (eGFR) at 3 mo after PN. A nomogram was built based on a multivariable model comprising age, sex, body mass index, baseline eGFR, RENAL score, and ischemia time. Interval validation and calibration were performed using data from 676 patients for whom complete data were available. Receiver operator characteristic (ROC) curves with 1000 bootstrap replications were plotted, as well as the observed incidence versus the nomogram-predicted probability. We also applied the extreme training versus test procedure known as leave-one-out cross-validation. After internal validation, the area under the ROC curve was 76%. The model demonstrated excellent calibration. At an upstaging cutoff of 27% probability, upstaging was predicted with a positive predictive value of 86%. PATIENT SUMMARY: In this report, we created a model to predict postoperative loss of renal function after partial nephrectomy for renal tumors. Inputting baseline characteristics and ischemia time into our model allows early identification of patients at higher risk of renal function decline after partial nephrectomy with good predictive power.

Management of the small renal mass

The increasing use of cross-sectional imaging has led to an increase in the diagnosis of incidental small renal masses (SRMs). About 20% of such masses are benign, while a significant proportion of malignant SRMs demonstrate slow growth kinetics and non-aggressive histologic features. Given these characteristics, lesions that were traditionally treated surgically are increasingly managed with less aggressive approaches. Further contributing to the evolving management paradigm is accumulating evidence supporting the safety of active surveillance and the efficacy of percutaneous renal mass biopsy in guiding management decisions. This review first discusses the epidemiology and diagnostic work-up of SRMs. The available management options are then examined, with emphasis placed on the clinical factors considered in selecting an appropriate approach. The existing evidence and long-term outcomes of each strategy are discussed. Finally, an overview of the current paradigm for the management of a patient with a SRM is provided. The goal is to provide physicians with the necessary understanding to appropriately manage this increasingly common condition.

The impact of T1 renal tumor characteristics on baseline renal function in patients undergoing partial nephrectomy: A renal scan based objective assessment

INTRODUCTION AND OBJECTIVES

To objectively assess the impact of renal tumors characteristics and other measurable factors on baseline renal function in patient undergoing partial nephrectomy (PN).

METHODS

Patients who underwent laparoscopic PN for a T1 renal mass between 2012 and 2016 and who also had a mercapto-acetyltriglycine renal scan prior to surgery were retrieved from a single institution prospectively-collected database. Split renal function (SRF) and Effective Renal Plasma Flow (ERPF) for both the operated kidney and the unaffected contralateral were calculated. Patient demographics and tumor characteristics (e.g. size, location and; nephrometry score) were assessed. Renal function of both the operated and the unaffected; contralateral kidney were compared. Statistical analysis was performed by using Statistica 8.0 (StatSoft).

RESULTS

227 patients were deemed eligible and included in the analysis. Univariable analysis showed a significant impact of age-adjusted CCI (p = 0.027), hypertension (p = 0.031) and age (p < 0.001) on operated kidney ERPF. Gender (p = 0.011), hypertension (p = 0.042), CCI (both standard and age-adjusted, p = 0.021 and = 0.003, respectively) and age (p < 0.001) were significantly; associated with contralateral unaffected kidney ERPF. Multivariable analysis confirmed age (p < 0.001) and hypertension (p < 0.021) as independent factors in both the operated and the unaffected kidney.

CONCLUSIONS

Characteristics of the renal mass (including nephrometry score and size) seem to have no clinically relevant impact on baseline renal function in patients undergoing partial nephrectomy for cT1 renal tumors. Age, hypertension and co-morbidities confirm to represent un-modifiable significant factors influencing baseline renal function.

Partial Nephrectomy Versus Radical Nephrectomy for Clinical T1b and T2 Renal Tumors: A Systematic Review and Meta-analysis of Comparative Studies

BACKGROUND

Partial nephrectomy (PN) is the reference standard of management for a cT1a renal mass. However, its role in the management of larger tumors (cT1b and cT2) is still under scrutiny.

OBJECTIVE

To conduct a meta-analysis assessing functional, oncologic, and perioperative outcomes of PN and radical nephrectomy (RN) in the specific case of larger renal tumors (≥cT1b). The primary endpoint was an overall analysis of cT1b and cT2 masses. The secondary endpoint was a sensitivity analysis for cT2 only.

EVIDENCE ACQUISITION

A systematic literature review was performed up to December 2015 using multiple search engines to identify eligible comparative studies. A formal meta-analysis was performed for studies comparing PN to RN for both cT1b and cT2 tumors. In addition, a sensitivity analysis including the subgroup of studies comparing PN to RN for cT2 only was conducted. Pooled estimates were calculated using a fixed-effects model if no significant heterogeneity was identified; alternatively, a random-effects model was used when significant heterogeneity was detected. For continuous outcomes, the weighted mean difference (WMD) was used as summary measure. For binary variables, the odds ratio (OR) or risk ratio (RR) was calculated with 95% confidence interval (CI). Statistical analyses were performed using Review Manager 5 (Cochrane Collaboration, Oxford, UK).

EVIDENCE SYNTHESIS

Overall, 21 case-control studies including 11204 patients (RN 8620; PN 2584) were deemed eligible and included in the analysis. Patients undergoing PN were younger (WMD -2.3 yr; p<0.001) and had smaller masses (WMD -0.65cm; p<0.001). Lower estimated blood loss was found for RN (WMD 102.6ml; p<0.001). There was a higher likelihood of postoperative complications for PN (RR 1.74, 95% CI 1.34-2.2; p<0.001). Pathology revealed a higher rate of malignant histology for the RN group (RR 0.97; p=0.02). PN was associated with better postoperative renal function, as shown by higher postoperative estimated glomerular filtration rate (eGFR; WMD 12.4ml/min; p<0.001), lower likelihood of postoperative onset of chronic kidney disease (RR 0.36; p<0.001), and lower decline in eGFR (WMD -8.6ml/min; p<0.001). The PN group had a lower likelihood of tumor recurrence (OR 0.6; p<0.001), cancer-specific mortality (OR 0.58; p=0.001), and all-cause mortality (OR 0.67; p=0.005). Four studies compared PN (n=212) to RN (n=1792) in the specific case of T2 tumors (>7cm). In this subset of patients, the estimated blood loss was higher for PN (WMD 107.6ml; p<0.001), as was the likelihood of complications (RR 2.0; p<0.001). Both the recurrence rate (RR 0.61; p=0.004) and cancer-specific mortality (RR 0.65; p=0.03) were lower for PN.

CONCLUSIONS

PN is a viable treatment option for larger renal tumors, as it offers acceptable surgical morbidity, equivalent cancer control, and better preservation of renal function, with potential for better long-term survival. For T2 tumors, PN use should be more selective, and specific patient and tumor factors should be considered. Further investigation, ideally in a prospective randomized fashion, is warranted to better define the role of PN in this challenging clinical scenario.

PATIENT SUMMARY

We performed a cumulative analysis of the literature to determine the best treatment option in cases of localized kidney tumor of higher clinical stage (T1b and T2, as based on preoperative imaging). Our findings suggest that removing only the tumor and saving the kidney might be an effective treatment modality in terms of cancer control, with the advantage of preserving the kidney function. However, a higher risk of perioperative complications should be taken into account when facing larger tumors (clinical stage T2) with kidney-sparing surgery.

Primary Renal Rhabdomyosarcoma: An Unusual Bone Metastasizing Tumor of Kidney

Rhabdomyosarcoma (RMS) is one of the common malignant tumors in the pediatric age group. There is only a single case report of primary renal alveolar RMS. Fine needle aspiration (FNA) findings of primary renal RMS has not been reported so far. Hence we present an unusual case of primary alveolar RMS of the kidney. An 11 year old boy presented with an abdominal mass. On FNA a diagnosis of undifferentiated sarcoma and anaplastic Wilms tumor were considered. The tumor was resected and showed histopathological features of alveolar rhabdomyosarcoma. He developed multiple bony metastases and succumbed to the illness despite aggressive chemotherapy. RMS of the kidney should be considered in the differential diagnosis of children with a renal mass, and may have an aggressive clinical course with bone metastases.

Low yield of surveillance imaging after surgery for T1 kidney cancer

PURPOSE

To examine the mode of relapse detection and subsequent treatment after partial or radical nephrectomy in patients with low-risk (pT1, N0, Nx) kidney cancer.

METHODS

Retrospective study on 1404 patients treated with partial or radical nephrectomy for low-risk kidney cancer from the years 2000-2012. Scans for chest imaging (X-ray or CT) and abdominal imaging (CT, MRI, or ultrasound) are tabulated. For those patients with relapse, the site, mode of detection, and symptoms were recorded.

RESULTS

Twenty-one patients relapsed with a median follow-up of 4.1 years for patients who did not relapse. In 17 (81 %) patients, relapse was detected by imaging alone, while 4 (19 %) patients presented with symptoms. Of the patients who relapsed by imaging, 13 (76 %) were treated immediately, while 4 (24 %) continued observation. During the first 3 years of follow-up, 5762 imaging studies were performed to detect 8 relapses, with 6 patients receiving immediate treatment. The median number of imaging studies per patient per year for the first 3 years was 1.7 (interquartile range 1.0, 2.3) including 30 % CT, 3 % MRI, 36 % X-ray, and 31 % ultrasounds.

CONCLUSION

We found a low yield of surveillance imaging in the first 3 years for pT1 kidney cancer. Nearly 1000 imaging studies were performed to detect one relapse that required treatment. Further studies are needed to evaluate the clinical impact of imaging surveillance according to recent guidelines.

Comparison between laparoscopic and open radical nephrectomy for the treatment of primary renal tumors in children: single-center experience over a 5-year period

OBJECTIVES

To compare the outcomes of laparoscopic nephrectomy (LN) with open radical nephrectomy (ORN) in the management of consecutive pediatric neoplasms.

PATIENTS AND METHODS

Retrospective cohort study of consecutive children treated for primary renal tumors between 2006 and 2011, segregated based on surgical modality (LN/ORN). Pre-, intra- and postoperative data and outcomes were collected.

RESULTS

Demographics from the 45 patients (13 LN, 32 ORN) were similar, and tumors in the LN group were smaller [6.59 ± 1.8 cm vs. 10.99 ± 2.99 cm ORN (p < 0.05)]. Six patients had preoperative chemotherapy (two LN, four ORN). No tumor ruptures occurred with either technique. Wilms tumor (seven LN, 24 ORN) was the most common diagnosis, followed by renal cell carcinoma (four LN, four ORN). Procedure length was similar between groups (282 ± 79 LN, 263 ± 81 min ORN). Mean length of stay was significantly shorter for LN (2.9 vs. 5.9 days; p = 0.002). Postoperative narcotic requirements and use of nasogastric tube were higher in the ORN group. After a median follow-up of 18 (LN) and 33 months (ORN), 1 and 4 recurrences occurred, respectively.

CONCLUSIONS

LN is an attractive alternative to open surgery in carefully selected cases of pediatric renal tumors. Procedure length and incidence of intra-operative rupture were not increased, while post-operative recovery and hospital stay were shorter for LN. Longer follow-up is mandatory to confirm comparable oncological outcomes to ORN.

PAX8 expression in sporadic hemangioblastoma of the kidney supports a primary renal cell lineage: implications for differential diagnosis

Hemangioblastoma is a benign, morphologically distinctive neoplasm of disputed histogenesis that typically occurs in the central nervous system either in the setting of von Hippel-Lindau disease or more often sporadically. Extraneural hemangioblastoma is exceptional and raises a challenging differential diagnosis. Herein, we report a primary renal hemangioblastoma occurring in 51-year-old woman without stigmata of von Hippel-Lindau disease. Histologically, the tumor was composed of sheets of polygonal epithelioid stromal cells with ample pale or eosinophilic, vacuolated cytoplasm in an arborizing capillary network. Tumor cells showed variable nuclear pleomorphism, intranuclear cytoplasmic invaginations, scattered hyaline globules, and psammoma-like calcifications. Some areas showed branching hemangiopericytoma-like vessels with tumor cells radiating from the wall, while other areas were edematous and hyalinized with sparse stromal cells and abundant reticular vessels. Immunohistochemically, the tumor cells reacted strongly and diffusely with antibodies to PAX8, CD10, α-inhibin, S100 protein, neuron-specific enolase, and vimentin, and they showed focal positivity with antibodies to epithelial membrane antigen and AE1/AE3. Tumor cells were negative for CK7, CK8/18, RCC antigen, synaptophysin, chromogranin, c-kit, D2-40, HMB45, melan-A, cathepsin K, SMA, desmin, CD31, CD34, and estrogen and progesterone receptors. Positive immunoreactivity for PAX8 is unexpected and contrasts to central nervous system (CNS) hemangioblastomas, which are essentially always negative for PAX8. This novel finding adds support to the hypothesis that the immunoprofile of extraneural hemangioblastoma varies with site of origin, perhaps as a result of tumor cell lineage and retention of organ-specific markers or acquisition of site-specific antigens due to local factors.

Robotic partial nephrectomy outcomes at a single institution and experience with R.E.N.A.L. nephrometry score

Partial nephrectomy is the current gold-standard treatment of small renal masses. The articulated instruments of the surgical robot have made the laparoscopic approach more feasible. We present our experience with 50 robot-assisted laparoscopic partial nephrectomy (RALPN) surgeries and attempt to validate a recently reported nephrometry score. From July 2008 to July 2010, 50 (53 planned) elective RALPNs were performed utilizing the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA). All patients had an enhancing renal mass on CT scan pre-operatively. Clinicopathologic, surgical, and renal functional (Cockcroft-Gault formula) outcomes were recorded prospectively and analyzed. Mean tumor size, length of surgery (LS), warm ischemia time (WIT), and nephrometry scores were 3.6 cm (1-8), 303 min (133-610), 29.1 min (11-42), and 6.8 (4-11) respectively. Renal cell carcinoma was found in 39 (78%) patients. When evaluating the nephrometry score, comparison of low, medium, and high complexity tumors for length of surgery, WIT, and estimated blood loss (EBL) showed no difference (p > 0.05). Nearness to the collecting system (N score 1 vs. N score 3) showed increased EBL (195 ml vs. 510 mL, p = 0.005), and location relative to polar lines (L score 1 and L score 2) increased mean LS (265 vs. 359 min, p = 0.02). RALPN is safe and effective. Nephrometry scores are a method of standardizing tumor complexity and can be utilized in comparing tumor cohorts but may not be predictive of intra-operative outcomes.