Incidence and predictors of ipsilateral local recurrence following partial nephrectomy.

PURPOSE: Ipsilateral local recurrence (LR) after partial nephrectomy (PN) for renal cell carcinoma (RCC) may result from a metachronous tumor or PN bed recurrence. To date, literature has predominantly reported ipsilateral LRs collectively, although the pathophysiology and prognostic implications of these event may be distinct. We sought to assess variables associated with LR and evaluated associations of LR with metastasis and death from RCC. MATERIALS AND METHODS: We identified adults undergoing PN for unilateral, sporadic, localized RCC from 2000 to 2019 using a prospectively maintained, single institution registry. LR was defined as new, enhancing tumor within/near the PN bed on MRI/CT. Cox proportional hazards models were used to create a preoperative risk score for LR and to examine the association of LR with metastasis and CSS following PN among patients with clear cell RCC. RESULTS: In a cohort of 2,164 PNs, 106 true LRs were identified, for a 10-year incidence of 6.2%. A preoperative risk score for LR based on age, symptoms, solitary kidney, complex tumor necessitating open partial nephrectomy, and cT stage was created (c-index = 0.73). Postoperatively, positive margins, pT stage, and clear cell subtype were associated with LR. Notably, 21% (23/106) of patients with LR presented with synchronous metastases. Following LR, 5-year metastasis-free and cancer-specific survival were 64% and 71%, respectively. LR remained associated with metastasis (HR 6.25; P < 0.001) and death from RCC (HR 1.93; P = 0.03) on multivariable analysis. CONCLUSIONS: We developed a preoperative risk score to identify patients at risk for LR following PN. LR was an independent risk factor for metastasis and death from RCC. Further study is warranted to determine whether treatment of LR improves oncologic outcomes.

Open and Robotic Uretero-enteric Stricture Repair: Early Outcomes and Complications.

Objective: To characterize our single institutional experience with robotic and open uretero-enteric stricture (UES) repair. Materials and Methods: We queried our ureteral reconstructive database for UES repair between 01/2017 and 10/2023. Patients with <3 months follow-up were excluded. Prior to surgery, patients underwent ureteral rest (4 weeks) with conversion to nephrostomy tube. Clinical characteristics, complications, reconstructive success (uretero-enteric patency), need for repeat intervention, and renal function were assessed in patients undergoing open and robotic UES reconstruction. Results: Of 50 patients undergoing UES repair during the study period, 45 were included for analysis due to complete follow-up (34 [76%] robotic and 11 [24%] open repair). UES repair was performed in 50 renal units a median of 13 months (interquartile range 7-30) from index surgery, and most often involved the left renal unit (34/50; 68%). Compared with robotic, open cases were significantly more likely to have undergone open cystectomy (100% vs 68%, p = 0.04), have longer strictures (median 4 vs 1 cm, p < 0.001), require tissue substitution (27% vs 3%, p = 0.04), and have lengthier postoperative hospitalization (5 vs 2 days, p < 0.001). There was no significant difference in total operative time (410 vs 322 minutes) or 30d major complications (18% vs 21%). At a follow-up of 13 months, per patient reconstructive success was 100% (11/11) for open and 97% (33/34) for robotic, respectively. Conclusion: In select patients with short UES unlikely to require advanced reconstructive techniques, a robotic-assisted approach can be considered. Careful patient selection is associated with limited morbidity and high reconstructive success.

End-Stage Kidney Disease After Partial and Radical Nephrectomy Among Patients with Severe Chronic Kidney Disease.

PURPOSE: AUA guidelines prioritize nephron sparing in patients with preexisting chronic kidney disease (CKD). However, few studies analyze long-term renal function in patients with preoperative severe CKD who undergo extirpative renal surgery. Herein, we compare the hazard of progression to end-stage kidney disease (ESKD) following partial nephrectomy (PN) and radical nephrectomy (RN) among patients with preoperative severe CKD. MATERIALS AND METHODS: Patients with stage 4 CKD who underwent PN or RN from 1970 to 2018 were identified. A multivariable Fine-Gray subdistribution hazard model was employed to assess associations with progression to ESKD accounting for the competing risk of death. RESULTS: A total of 186 patients with stage 4 CKD underwent PN (n = 71; 38%) or RN (n = 115; 62%) for renal neoplasms with median follow-up of 6.9 years (interquartile range 3.8-14.1). On multivariable analyses adjusting for competing risk of death, the subdistribution hazard ratio (SHR) for older age at surgery (SHR for 5-year increase 0.81; 95% CI 0.73-0.91; P < .001) and higher preoperative estimated glomerular filtration rate (SHR for 5-unit increase 0.63; 95% CI 0.47-0.84; P = .002) was associated with lower hazard of progression to ESKD. There was no significant difference in hazard of ESKD between PN and RN (SHR 0.82; 95% CI 0.50-1.33; P = .4). CONCLUSIONS: Among patients with preoperative severe CKD, higher preoperative estimated glomerular filtration rate was associated with lower hazard of progression to ESKD after extirpative surgery for renal neoplasms. We did not observe a significant difference in overall hazard for developing ESKD between PN and RN.

Mayo Clinic Validation of the AUA Risk Groups for Localized Renal Cell Carcinoma.

PURPOSE: The AUA guidelines introduced a new risk group stratification system based primarily on tumor stage and grade to guide surveillance for patients treated surgically for localized renal cell carcinoma (RCC). We sought to evaluate the predictive ability of these risk groups using progression-free survival (PFS) and cancer-specific survival (CSS), and to compare their performance to that of our published institutional risk models. MATERIALS AND METHODS: We queried our Nephrectomy Registry to identify adults treated with radical or partial nephrectomy for unilateral, M0, clear cell RCC, or papillary RCC from 1980 to 2012. The AUA stratification does not apply to other RCC subtypes as tumor grading for other RCC, such as chromophobe, is not routinely performed. PFS and CSS were estimated using the Kaplan-Meier method. Predictive abilities were evaluated using C indexes from Cox proportional hazards regression models. RESULTS: A total of 3191 patients with clear cell RCC and 633 patients with papillary RCC were included. For patients with clear cell RCC, C indexes for the AUA risk groups and our model were 0.780 and 0.815, respectively (P < .001) for PFS, and 0.811 and 0.857, respectively (P < .001), for CSS. For patients with papillary RCC, C indexes for the AUA risk groups and our model were 0.775 and 0.751, respectively (P = .002) for PFS, and 0.830 and 0.803, respectively (P = .2) for CSS. CONCLUSIONS: The AUA stratification is a parsimonious system for categorizing RCC that provides C indexes of about 0.80 for PFS and CSS following surgery for localized clear cell and papillary RCC.

Initial Experience and Clinical Assessment of the Karl Storz FLEX-XC1 Single-Use Flexible Ureteroscope.

INTRODUCTION: The Karl Storz FLEX-XC1 is a novel single-use flexible ureteroscope that uses the same videographics platform as its reusable digital counterpart. We evaluated the technical performance of the FLEX-XC1 in its initial clinical use. METHODS: We reviewed a series of consecutive ureteroscopy procedures performed by 2 endourologists using the FLEX-XC1 for indications for which we typically use a single-use device: total stone burden > 15 mm or > 10 mm in the lower pole, anticipated case duration > 60 minutes, bilateral procedure, or upper tract urothelial cancer procedures. We assessed device tip deflection, intraoperative mechanical failure, and clinical outcomes for each case. Surgeons rated visual clarity, image quality, and maneuverability on a 1 to 5 Likert scale. RESULTS: Of 29 procedures using FLEX-XC1, 27 (93%) were successfully completed. Preoperative upward deflection was < 270° in 6 (21%) cases, and downward deflection was < 270° in 9 (31%) cases. Three types of intraoperative malfunctions occurred: rotational twisting of deflectable tip (4 cases, 13%), device not advancing through distal ureter (1 case, 3%), and working channel not accommodating a 365-µm laser (1 case, 3%). Visual clarity, image quality, and maneuverability were rated as 5 "very good" or 4 "good" in 100%, 100%, and 97% of cases, respectively. No device-specific or general 30-day complications were observed. CONCLUSIONS: The FLEX-XC1 showed comparable image quality and maneuverability to reusable digital devices. We observed incomplete deflection in up to 31% of cases and mechanical failure in 2 cases. The FLEX-XC1 may be advantageous in prolonged cases where maintaining visual clarity is paramount.

Development and Validation of a Multivariable Nomogram Predictive of Post-Nephroureterectomy Renal Function.

BACKGROUND AND OBJECTIVE: The timing of perioperative nephrotoxic chemotherapy for upper tract urothelial carcinoma (UTUC) remains controversial and strongly depends on predicted platinum eligibility after radical nephroureterectomy (RNU). The study objective was to develop and validate a multivariable nomogram to predict estimated glomerular filtration rate (eGFR) following RNU. METHODS: This was a multi-institutional retrospective study of patients with UTUC treated with RNU from 2000 to 2020 at seven high-volume referral centers. Use of adjuvant chemotherapy was risk-stratified. Patients were retrospectively randomly allocated 2:1 to discovery and validation cohorts. Discovery data were used to identify independent factors associated with GFR at 1-3 mo after RNU on linear regression, and backward selection was applied for model construction. Accuracy was defined as the percentage of predicted eGFR results within 30% of the corresponding observed eGFR. KEY FINDINGS AND LIMITATIONS: We included 1100 patients, of whom 733 were in the discovery and 367 were in the validation cohort. Multivariable predictors of postoperative eGFR decline included advanced age (odds ratio [OR] -0.18, 95% confidence interval [CI] -0.28 to -0.08), diabetes (OR -2.38, 95% CI -4.64 to -0.11), and hypertension (OR -2.24, 95% CI -4.16 to -0.32). Factors associated with favorable postoperative eGFR included larger tumor size (OR 10.57, 95% CI 7.4-13.74 for tumors >5 cm vs ≤2 cm) and preoperative eGFR (OR 0.44, 95% CI 0.39-0.49). A composite nomogram predicted postoperative eGFR with good accuracy in both the discovery (80.5%) and validation (78.6%) cohorts. Limitations include exclusion of patients who received neoadjuvant chemotherapy. CONCLUSIONS: A nomogram that incorporates ubiquitous preoperative clinical variables can predict post-RNU eGFR and was validated with an independent cohort. PATIENT SUMMARY: We developed a tool that uses patient data to predict eligibility for chemotherapy after surgery to remove the kidney and ureter in patients with cancer in the upper urinary tract.

Oncologic Outcomes in Patients with Residual Upper Tract Urothelial Carcinoma Following Neoadjuvant Chemotherapy.

BACKGROUND AND OBJECTIVE: Growing evidence supports the use of neoadjuvant chemotherapy (NAC) for upper tract urothelial carcinoma (UTUC). However, the implications of residual UTUC at radical nephroureterectomy (RNU) after NAC are not well characterized. Our objective was to compare oncologic outcomes for pathologic risk-matched patients who underwent RNU for UTUC who either received NAC or were chemotherapy-naïve. METHODS: We retrospectively identified 1993 patients (including 112 NAC recipients) who underwent RNU for nonmetastatic, high-grade UTUC between 1985 and 2022 in a large, international, multicenter cohort. We divided the cohort into low-risk and high-risk groups defined according to pathologic findings of muscle invasion and lymph node involvement at RNU. Recurrence-free survival (RFS), overall survival (OS), and cancer-specific survival (CSS) estimates were calculated using the Kaplan-Meier method. Multivariable analyses were performed to determine clinical and demographic factors associated with these outcomes. KEY FINDINGS AND LIMITATIONS: Among patients with low-risk pathology at RNU, RFS, OS, and CSS were similar between the NAC and chemotherapy-naïve groups. Among patients with high-risk pathology at RNU, the NAC group had poorer RFS (hazard ratio [HR] 3.07, 95% confidence interval [CI] 2.10-4.48), OS (HR 2.06, 95% CI 1.33-3.20), and CSS (subdistribution HR 2.54, 95% CI 1.37-4.69) in comparison to the pathologic risk-matched, chemotherapy-naïve group. Limitations include the lack of centralized pathologic review. CONCLUSIONS AND CLINICAL IMPLICATIONS: Patients with residual invasive disease at RNU after NAC represent a uniquely high-risk population with respect to oncologic outcomes. There is a critical need to determine an optimal adjuvant approach for these patients. PATIENT SUMMARY: We studied a large, international group of patients with cancer of the upper urinary tract who underwent surgery either with or without receiving chemotherapy beforehand. We identified a high-risk subgroup of patients with residual aggressive cancer after chemotherapy and surgery who should be prioritized for clinical trials and drug development.

Percutaneous Image Guided Cryoablation of Adrenal Metastases From Renal Cell Carcinoma: A Single Institution Review.

OBJECTIVES: To assess the safety, technical success, disease progression, and survival associated with percutaneous image-guided cryoablation of renal cell carcinoma metastasis (mRCC) in the adrenal gland. METHODS: Retrospective, single-institution review of adult patients undergoing percutaneous cryoablation for adrenal mRCC between the years of 2007-2021. Technical parameters, technical success, safety, and survival were analyzed according to standard criteria. RESULTS: Forty-six patients (39 male; mean age 66 ± 8.8 years) with 57 tumors ablated over 51 sessions with a median hospital length of stay of 1 day (range 0-3 days). Forty-four (96%) had primary of clear cell histology. Aim of ablation was curative intent in 39 of 57 tumors (72%) with local tumor control in the remainder. There were 2 (4%) technical failures and technique efficacy was achieved in 52 out of the remaining 55 (95%). There were no Common Terminology Criteria for Adverse Events' immediate complications and 4 of 51 (8%) delayed complications. Twenty-five of 57 (44%) had disease progression anywhere, away from ablation site. One-, 3-, and 5-year recurrence free survival rates were 100%, 89%, and 89% and overall survival was 98%, 85%, and 71%. Fifty-one of 57 (89%) underwent preprocedural alpha blockade with hypertensive crisis in 27 of 56 (54%) available records, of which there were no adverse outcomes. CONCLUSION: Percutaneous cryoablation of mRCC to the adrenal glands is safe with robust local control, leading to advocacy for its ongoing use in this patient population. Multi-disciplinary management is recommended for successful treatment.

Reuse and Reprocessing of Endoscopic Instruments: For.

Reusable endoscopes appear to be most environmentally sustainable when the carbon footprint of routine device maintenance is optimized. Single-use endoscopes may offer cost-savings in clinical settings that accelerate device damage, such as prolonged procedure time or complex patient anatomy. For many urology practices, a hybrid approach that integrates single-use and reusable devices may be most economically sensible and environmentally sound.

Examination of nutritional factors associated with urolithiasis risk in plant based meat alternatives marketed to children and infants.

INTRODUCTION: The global prevalence of pediatric nephrolithiasis continues to rise amidst increased sodium and animal protein intake. Plant-based meat alternatives (PBMAs) have recently gained popularity due to health benefits, environmental sustainability, and increased retail availability. PBMAs have the potential to reduce the adverse metabolic impact of animal protein on kidney stone formation. We analyzed PBMAs targeted to children to characterize potential lithogenic risk vs animal protein. METHODS: We performed a dietary assessment using a sample of PBMAs marketed to or commonly consumed by children and commercially available at national retailers. Nutrient profiles for PBMAs were compiled from US Department of Agriculture databases and compared to animal protein sources using standardized serving sizes. We also analyzed nutrient profiles for plant-based infant formulas against typical dairy protein-based formulas. Primary protein sources were identified using verified ingredient lists. Oxalate content was extrapolated from dietary data sources. RESULTS: A total of 41 PBMAs were analyzed: chicken (N = 18), hot dogs (N = 3), meatballs (N = 5), fish (N = 10), and infant formula (N = 5). Most products (76%) contained a high-oxalate ingredient as the primary protein source (soy, wheat, or almond). Average oxalate content per serving was substantially higher in these products (soy 11.6 mg, wheat 3.8 mg, almond 10.2 mg) vs animal protein (negligible oxalate). PBMAs containing pea protein (24%) had lower average oxalate (0.11 mg). Most PBMAs averaged up to six times more calcium and three times more sodium per serving compared to their respective animal proteins. Protein content was similar for most categories. CONCLUSIONS: Three-quarters of the examined plant-based meat products for children and infants contain high-oxalate protein sources. Coupled with higher per-serving sodium and calcium amounts, our findings raise questions about possible lithogenic risk in some PBMAs, and further studies are needed to assess the relationship between PBMAs and nephrolithiasis.

Diagnosis and Management of Non-Metastatic Upper Tract Urothelial Carcinoma: AUA/SUO Guideline.

PURPOSE: The purpose of this guideline is to provide a useful reference on the effective evidence-based diagnoses and management of non-metastatic upper tract urothelial carcinoma (UTUC). MATERIALS/METHODS: The Pacific Northwest Evidence-based Practice Center of Oregon Health & Science University (OHSU) team conducted searches in Ovid MEDLINE (1946 to March 3rd, 2022), Cochrane Central Register of Controlled Trials (through January 2022), and Cochrane Database of Systematic Reviews (through January 2022). The searches were updated August 2022. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (Table 1).[Table: see text]Results:This Guideline provides updated, evidence-based recommendations regarding diagnosis and management of non-metastatic UTUC including risk stratification, surveillance and survivorship. Treatments discussed include kidney sparing management, surgical management, lymph node dissection (LND), neoadjuvant/adjuvant chemotherapy and immunotherapy. CONCLUSION: This standardized guideline seeks to improve clinicians' ability to evaluate and treat patients with UTUC based on available evidence. Future studies will be essential to further support these statements for improving patient care. Updates will occur as the knowledge regarding disease biology, clinical behavior and new therapeutic options develop.

Healthcare system contact following ureteroscopy: does discharge instruction readability matter?

INTRODUCTION: We aimed to assess the impact of discharge instruction (DCI) readability on 30-day postoperative contact with the healthcare system. MATERIALS AND METHODS: Utilizing a multidisciplinary team, DCI were modified for patients undergoing cystoscopy, retrograde pyelogram, ureteroscopy, laser lithotripsy, and stent placement (CRULLS) from a 13th grade to a 7th grade reading level. We retrospectively reviewed 100 patients including 50 consecutive patients with original DCI (oDCI) and 50 consecutive patients with improved readability DCI (irDCI). Clinical and demographic data collected including healthcare system contact (communications [phone or electronic message], emergency department [ED], and unplanned clinic visits) within 30 days of surgery. Uni/multivariate logistic regression analyses used to identify factors, including DCI-type, associated with increased healthcare system contact. Findings reported as odds ratios with 95% confidence intervals and p values (< 0.05 significant). RESULTS: There were 105 contacts to the healthcare system within 30 days of surgery: 78 communications, 14 ED visits and 13 clinic visits. There were no significant differences between cohorts in the proportion of patients with communications (p = 0.16), ED visits (p =1.0) or clinic visits (p = 0.37). On multivariable analysis, older age and psychiatric diagnosis were associated with significantly increased odds of overall healthcare contact (p = 0.03 and p = 0.04) and communications (p = 0.02 and p = 0.03). Prior psychiatric diagnosis was also associated with significantly increased odds of unplanned clinic visits (p = 0.003). Overall, irDCI were not significantly associated with the endpoints of interest. CONCLUSIONS: Increasing age and prior psychiatric diagnosis, but not irDCI, were significantly associated with an increased rate of healthcare system contact following CRULLS.

Effect of Dataset Size and Medical Image Modality on Convolutional Neural Network Model Performance for Automated Segmentation: A CT and MR Renal Tumor Imaging Study.

The aim of this study is to investigate the use of an exponential-plateau model to determine the required training dataset size that yields the maximum medical image segmentation performance. CT and MR images of patients with renal tumors acquired between 1997 and 2017 were retrospectively collected from our nephrectomy registry. Modality-based datasets of 50, 100, 150, 200, 250, and 300 images were assembled to train models with an 80-20 training-validation split evaluated against 50 randomly held out test set images. A third experiment using the KiTS21 dataset was also used to explore the effects of different model architectures. Exponential-plateau models were used to establish the relationship of dataset size to model generalizability performance. For segmenting non-neoplastic kidney regions on CT and MR imaging, our model yielded test Dice score plateaus of [Formula: see text] and [Formula: see text] with the number of training-validation images needed to reach the plateaus of 54 and 122, respectively. For segmenting CT and MR tumor regions, we modeled a test Dice score plateau of [Formula: see text] and [Formula: see text], with 125 and 389 training-validation images needed to reach the plateaus. For the KiTS21 dataset, the best Dice score plateaus for nn-UNet 2D and 3D architectures were [Formula: see text] and [Formula: see text] with number to reach performance plateau of 177 and 440. Our research validates that differing imaging modalities, target structures, and model architectures all affect the amount of training images required to reach a performance plateau. The modeling approach we developed will help future researchers determine for their experiments when additional training-validation images will likely not further improve model performance.

Comparing Oncological and Perioperative Outcomes of Open versus Laparoscopic versus Robotic Radical Nephroureterectomy for the Treatment of Upper Tract Urothelial Carcinoma: A Multicenter, Multinational, Propensity Score-Matched Analysis.

OBJECTIVES: To identify correlates of survival and perioperative outcomes of upper tract urothelial carcinoma (UTUC) patients undergoing open (ORNU), laparoscopic (LRNU), and robotic (RRNU) radical nephroureterectomy (RNU). METHODS: We conducted a retrospective, multicenter study that included non-metastatic UTUC patients who underwent RNU between 1990-2020. Multiple imputation by chained equations was used to impute missing data. Patients were divided into three groups based on their surgical treatment and were adjusted by 1:1:1 propensity score matching (PSM). Survival outcomes per group were estimated for recurrence-free survival (RFS), bladder recurrence-free survival (BRFS), cancer-specific survival (CSS), and overall survival (OS). Perioperative outcomes: Intraoperative blood loss, hospital length of stay (LOS), and overall (OPC) and major postoperative complications (MPCs; defined as Clavien-Dindo > 3) were assessed between groups. RESULTS: Of the 2434 patients included, 756 remained after PSM with 252 in each group. The three groups had similar baseline clinicopathological characteristics. The median follow-up was 32 months. Kaplan-Meier and log-rank tests demonstrated similar RFS, CSS, and OS between groups. BRFS was found to be superior with ORNU. Using multivariable regression analyses, LRNU and RRNU were independently associated with worse BRFS (HR 1.66, 95% CI 1.22-2.28, p = 0.001 and HR 1.73, 95%CI 1.22-2.47, p = 0.002, respectively). LRNU and RRNU were associated with a significantly shorter LOS (beta -1.1, 95% CI -2.2-0.02, p = 0.047 and beta -6.1, 95% CI -7.2-5.0, p < 0.001, respectively) and fewer MPCs (OR 0.5, 95% CI 0.31-0.79, p = 0.003 and OR 0.27, 95% CI 0.16-0.46, p < 0.001, respectively). CONCLUSIONS: In this large international cohort, we demonstrated similar RFS, CSS, and OS among ORNU, LRNU, and RRNU. However, LRNU and RRNU were associated with significantly worse BRFS, but a shorter LOS and fewer MPCs.