The PRO-RCC study: a long-term PROspective Renal Cell Carcinoma cohort in the Netherlands, providing an infrastructure for 'Trial within Cohorts' study designs.

BACKGROUND: Ongoing research in the field of both localized, locally advanced and metastatic renal cell carcinoma has resulted in the availability of multiple treatment options. Hence, many questions are still unanswered and await further research. A nationwide collaborative registry allows to collect corresponding data. For this purpose, the Dutch PROspective Renal Cell Carcinoma cohort (PRO-RCC) has been founded, for the prospective collection of long-term clinical data, patient reported outcome measures (PROMs) and patient reported experience measures (PREMs). METHODS: PRO-RCC is designed as a multicenter cohort for all Dutch patients with renal cell carcinoma (RCC). Recruitment will start in the Netherlands in 2023. Importantly, participants may also consent to participation in a 'Trial within cohorts' studies (TwiCs). The TwiCs design provides a method to perform (randomized) interventional studies within the registry. The clinical data collection is embedded in the Netherlands Cancer Registry (NCR). Next to the standardly available data on RCC, additional clinical data will be collected. PROMS entail Health-Related Quality of Life (HRQoL), symptom monitoring with optional ecological momentary assessment (EMA) of pain and fatigue, and optional return to work- and/or nutrition questionnaires. PREMS entail satisfaction with care. Both PROMS and PREMS are collected through the PROFILES registry and are accessible for the patient and the treating physician. TRIAL REGISTRATION: Ethical board approval has been obtained (2021_218) and the study has been registered at ClinicalTrials.gov (NCT05326620). DISCUSSION: PRO-RCC is a nationwide long-term cohort for the collection of real-world clinical data, PROMS and PREMS. By facilitating an infrastructure for the collection of prospective data on RCC, PRO-RCC will contribute to observational research in a real-world study population and prove effectiveness in daily clinical practice. The infrastructure of this cohort also enables that interventional studies can be conducted with the TwiCs design, without the disadvantages of classic RCTs such as slow patient accrual and risk of dropping out after randomization.

Cancer detection and complications of transperineal prostate biopsy with antibiotics when indicated.

OBJECTIVES: To describe the prostate cancer (PCa) detection rate, including clinically significant prostate cancer (csPCa), in a large cohort of patients who underwent transperineal ultrasonography-guided systematic prostate biopsy (TPB-US) using a probe-mounted transperineal access system, with magnetic resonance imaging (MRI) cognitive fusion in case of a Prostate Imaging-Reporting and Data System grade 3-5 lesion, under local anaesthesia in an outpatient setting. Additionally, to compare the incidence of procedure-related complications with a cohort of patients undergoing transrectal ultrasonography-guided (TRB-US) and transrectal MRI-guided biopsies (TRB-MRI). PATIENTS AND METHODS: This was an observational cohort study in men who underwent TPB-US prostate biopsy in a large teaching hospital. For each participant, prostate-specific antigen level, clinical tumour stage, prostate volume, MRI parameters, number of (targeted) prostate biopsies, biopsy International Society of Uropathology (ISUP) grade and procedure-related complications were assessed. csPCa was defined as ISUP grade ≥2. Antibiotic prophylaxis was only given in those with an increased risk of urinary tract infection. RESULTS: A total of 1288 TPB-US procedures were evaluated. The overall detection rate for PCa in biopsy-naive patients was 73%, and for csPCa it was 63%. The incidence of hospitalization was 1% in TPB-US (13/1288), compared to 4% in TRB-US (8/214) and 3% in TRB-MRI (7/219; P = 0.002). CONCLUSIONS: Contemporary combined systematic and target TPB-US with MRI cognitive fusion is easy to perform in an outpatient setting, with a high detection rate of csPCa and a low incidence of procedure-related complications.

A 6-month maintenance schedule of mitomycin C after radical nephroureterectomy for upper tract urothelial carcinoma for the prevention of intravesical recurrence: a retrospective, single center study.

PURPOSE: To show the effect of a 6-month (4 times weekly followed by 5 times monthly) maintenance mitomycin C regimen on the prevention of intravesical recurrence (IVR) after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). METHODS: A total of 119 patients undergoing a RNU between 2007 and 2021 in a single center hospital were retrospectively reviewed. A total of 66 patients were eligible for further analysis. 27 patients received no post-operative MMC (median follow-up: 110 months) and 39 patients received a 6-month (4 times weekly, 5 times monthly) maintenance regimen of MMC (median follow up: 48 months). The primary outcome was the 1-, 2- and 5-year bladder recurrence free survival (BRFS). RESULTS: There was a significant difference (p = 0.001) in BRFS between the two groups. The 1-, 2, and 5-year BRFS for the MMC- group was 67%, 63% and 43%, respectively. The 1-, 2- and 5-year BRFS for the MMC + group was 95%, 86% and 86%, respectively. Univariate analysis showed no other potential prognostic factors that had a significant effect on the BRFS. CONCLUSION: A 6-month maintenance schedule of MMC is effective at significantly reducing the risk of IVR after RNU for UTUC. We could not find any other significant prognostic factors to predict IVR.

Surgical margins after partial nephrectomy as prognostic factor for the risk of local recurrence in pT1 RCC: a systematic review and narrative synthesis.

PURPOSE: To systematically review the published literature on surgical margins as a risk factor for local recurrence (LR) in patients undergoing partial nephrectomy (PN) for pT1 renal cell carcinomas (RCC). EVIDENCE ACQUISITION: A systematic literature search of relevant databases (MEDLINE, Embase and the Cochrane Library) was performed according to the PRISMA criteria up to February 2022. The hypothesis was developed using the PPO method (Patients = patients with pT1 RCC undergoing PN, Prognostic factor = positive surgical margins (PSM) detected on final pathology versus negative surgical margins (NSM) and Outcome = LR diagnosed on follow-up imaging). The primary outcome was the rate of PSM and LR. The risk of bias was assessed by the QUIPS tool. EVIDENCE SYNTHESIS: After assessing 1525 abstracts and 409 full-text articles, eight studies met the inclusion criteria. The percentage of PSM ranged between 0 and 34.3%. In these patients with PSM, LR varied between 0 and 9.1%, whereas only 0-1.5% of LR were found in the NSM-group. The calculated odds ratio (95% confident intervals) varied between 0.04 [0.00-0.79] and 0.27 [0.01-4.76] and was statistically significant in two studies (0.14 [0.02-0.80] and 0.04 [0.00-0.79]). The quality analysis of the included studies resulted in an overall intermediate to high risk of bias and the level of evidence was overall very low. A meta-analysis was considered unsuitable due to the high heterogeneity between the included studies. CONCLUSION: PSM after PN in patients with pT1 RCC is associated with a higher risk of LR. However, the evidence has significant limitations and caution should be taken with the interpretation of this data.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry.

OBJECTIVES: To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs. METHODS: From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy. RESULTS: In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51-0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10-0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05). CONCLUSION: An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments. KEY POINTS: • The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019. • Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51-0.81, p < 0.001). • Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

Potential Risk and Safety Measures in Laparoscopy in COVID-19 Positive Patients.

Background. During the COVID-19 pandemic the question arises if laparoscopy, as an aerosol forming procedure, poses a potential risk for viral transmission of SARS-CoV-2 to healthcare workers. Methods. A literature search was conducted using PubMed, Embase and MEDLINE. Articles reporting information regarding COVID-19 or other relevant viruses and laparoscopy, surgical smoke, aerosols and viral transmission were included. Results. Although aerosols produced during laparoscopy do not originate from the respiratory tract, the main transmission route of SARS-CoV-2, research did show SARS-CoV-2 to be present in other body fluids. The transmission risk via this route is however considered very low. As previous research showed potential viral transmission during laparoscopy for viruses that spread through contaminated body fluids, there might be a potential risk of SARS-CoV-2 transmission during laparoscopy, albeit considered very small. Conclusion. Due to the small risk compared to widely known benefits of laparoscopy, there is no reason to replace laparoscopy by laparotomy due to COVID-19 infection. To avoid the potential small risk of viral transmission, additional safety measures are advised.

Outcome after resection of occult and non-occult lymph node metastases at the time of nephrectomy.

PURPOSE: There is sparse evidence on outcomes of resected occult LN metastases at the time of nephrectomy (synchronous disease). We sought to analyse a large international cohort of patients and to identify clinico-pathological predictors of long-term survival. MATERIALS AND METHODS: We collected data of consecutive patients who underwent nephrectomy and LND for Tany cN0-1pN1 and cM0-1 RCC at 7 referral centres between 1988 and 2019. Patients were stratified into four clinico-pathological groups: (1) cN0cM0-pN1, (2) cN1cM0-pN1(limited, 1-3 positive nodes), (3) cN1cM0-pN1(extensive, > 3 positive nodes), and (4) cM1-pN1. Overall survival (OS) was estimated using the Kaplan-Meier method, and associations with all-cause mortality (ACM) were evaluated using Cox models with multiple imputations. RESULTS: Of the 4370 patients with LND, 292 patients with pN1 disease were analysed. Median follow-up was 62 months, during which 171 patients died. Median OS was 21 months (95% CI 17-30 months) and the 5-year OS rate was 24% (95% CI 18-31%). Patients with cN0cM0-pN1 disease had a median OS of 57 months and a 5-year OS rate of 43%. 5-year OS (median OS) decreased to 29% (33 months) in cN1cM0-pN1(limited) and to 23% (23 months) in cN1cM0-pN1(extensive) patients. Those with cM1-pN1 disease had the worst prognosis, with a 5-year OS rate of 13% (9 months). On multivariable analysis, age (p = 0.034), tumour size (p = 0.02), grade (p = 0.02) and clinico-pathological group (p < 0.05) were significant predictors of ACM. CONCLUSION: Depending on clinico-pathological group, grade and tumour size, 5-year survival of patients with LN metastases varies from 13 to 43%. Patients with resected occult lymph node involvement (cN0/pN1 cM0) have the best prognosis with a considerable chance of long-term survival.

A Phase II, single-arm trial of neoadjuvant axitinib plus avelumab in patients with localized renal cell carcinoma who are at high risk of relapse after nephrectomy (NEOAVAX).

Surgery is the standard treatment for nonmetastatic renal cell carcinoma. Despite curative intent, patients with a high risk of relapse have a 5-year metastasis-free survival rate of only 30% and prevention of recurrence is an unmet need. In a Phase III trial (JAVELIN Renal 101), progression-free survival of axitinib + avelumab was superior to sunitinib with a favorable objective response rate and no added toxicity profiles as known for axitinib or avelumab single agent. NEOAVAX is designed as open label, single arm, Phase II trial with a Simon's two-stage design evaluating neoadjuvant axitinib + avelumab followed by complete surgical resection in 40 patients with high-risk nonmetastatic clear-cell renal cell carcinoma. Primary end point is remission of the primary tumor (RECIST 1.1; Response Evaluation Criteria In Solid Tumors) following neoadjuvant therapy. Secondary end points include disease-free survival, overall survival, rate of metastasis and local recurrence, safety, and tolerability. Exploratory end points include investigation of effects on neoangiogenesis, immune infiltrates and myeloid-derived suppressor cell components to support a rationale for the combined use of axitinib and avelumab (NCT03341845).

Renal cryoablation: Multidisciplinary, collaborative and perspective approach.

Renal cryoablation is becoming an established treatment option for small renal masses. It allows preservation of renal function without compromising cancer control. The technique has evolved considerably since it was first reported using liquid nitrogen over 20 years ago. We describe the modern technique for both laparoscopic and image guided renal cryoablation. Renal cryoablation is performed either laparoscopically or percutaneously depending on tumour characteristics. Common features include biopsy of the mass, protection of adjacent organs, and the use of compressed argon gas for freezing and helium for thawing. Dynamic monitoring is used to ensure adequate treatment. The shape of the iceball can be modified by adding extra needles or changing their positions. A double freeze/thaw is necessary for confident ablation of all cancer cells. The laparoscopic approach includes exposure of the tumour and may involve extensive mobilisation of the kidney. Laparoscopic ultrasound is essential for correct localisation of the tumour, needle placement, and monitoring the treatment. A Temperature probe is placed at the edge of the tumour to record treatment temperature. The percutaneous approach is typically performed with CT guidance. Adjacent organs can be protected by injecting saline or carbon dioxide. Early imaging is helpful to detect or rule out incomplete treatment. Post-operative follow-up is structured at specific intervals (e.g. 3, 6, 12 months then annually) and perhaps tailored or modified based on the degree of suspicion of inadequate treatment.

Oncological outcomes and complication rates after laparoscopic-assisted cryoablation: a European Registry for Renal Cryoablation (EuRECA) multi-institutional study.

OBJECTIVE: To assess complication rates and intermediate oncological outcomes of laparoscopic-assisted cryoablation (LCA) in patients with small renal masses (SRMs). PATIENTS AND METHODS: A retrospective review of 808 patients treated with LCA for T1a SRMs from 2005 to 2015 at eight European institutions. Complications were analysed according to the Clavien-Dindo classification. Kaplan-Meier analyses were used to estimate 5- and 10-year disease-free survival (DFS) and overall survival (OS). RESULTS: The median [interquartile (IQR)] age was 67 (58-74) years. The median (IQR) tumour size was 25 (19-30) mm. The transperitoneal approach was used in 77.7% of the patients. The median postoperative hospital stay was 2 days. In all, 514 patients with a biopsy-confirmed renal cell carcinoma (RCC) were available for survival analyses. The median (IQR) follow-up for the RCC-cohort was 36 (14-56) months. A total of 32 patients (6.2%) were diagnosed with treatment failure. The 5-/10-year DFS was 90.4%/80.0% and 5-/10-year OS was 83.2%/64.4%, respectively. A total of 134 postoperative complications (16.6%) were reported, with severe complications (grade ≥III) in 26 patients (3.2%). An American Society of Anesthesiologists score of 3 was associated with an increased risk of overall complications (odds ratio 2.85, 95% confidence interval 1.32-6.20; P = 0.005). CONCLUSIONS: This large series of LCA demonstrates satisfactory long-term oncological outcomes for SRMs. However, although LCA is considered a minimally invasive procedure, risk of complications should be considered when counselling patients.

The Impact of a Multidisciplinary Tumor Board (MTB) on Treatment Decision Making for Patients With Renal Cell Carcinoma (RCC): 5-Year Data Analysis.

OBJECTIVE: To describe the impact of a multidisciplinary tumor board (MTB) for renal cell carcinoma (RCC) patients in a locoregional renal cancer network by evaluating shared decision making (SDM) and adherence to MTB recommendations. DESIGN, SETTING AND PARTICIPANTS: This prospective cohort study included all cases from a Dutch renal cancer network with suspicion of or histologically confirmed RCC discussed in MTBs between 2017-2022. Main endpoints were distribution of cases presented, proportion of recommendations with multiple treatment options enabling shared decision making (SDM), definite treatment after SDM and adherence to MTB recommendations. Further endpoints were definite treatment per tumor stage stratified by age and inclusion in clinical trials. Outcomes were displayed as means and proportions (%). Pearson's Chi-Squared test was used to analyze the effect of age on definite treatment advice. RESULTS: Overall, 2651 cases were discussed, of which 1900 (72%) were new referrals and 751 (28%) rediscussions. Majority of cases were cT1a-b tumors (46%) and 22% were local recurrences or metachronous metastatic. Adherence to MTB recommendation was 96% and in 30% multiple treatment options were recommended, allowing for SDM. In 45% of cases with cT1a tumors multiple treatment options were recommended by the MTB, resulting in (cryo)ablation (32%) and AS (30%) as most frequent definite treatments after SDM. Among patients with cT3-4 tumors the inclusion rate in clinical trials was 47%. CONCLUSIONS: A network MTB creates opportunity to discuss multiple treatment options and clinical trials in SDM with patients at a high rate of adherence to MTB recommendation.

Renal Function After CT-Guided Cryoablation of Small Renal Tumours in Patients with Solitary Kidney: An Analysis of European Multinational Prospective EuRECA Registry.

PURPOSE: Treatment of renal cell carcinoma (RCC) in patients with solitary kidneys remains challenging. The purpose of this multicentre cohort study was to explore how renal function is affected by percutaneous image-guided cryoablation in patients with solitary kidneys. MATERIAL AND METHODS: Data from the European Registry for Renal Cryoablation database were extracted on patients with RCC in solitary kidneys treated with image-guided, percutaneous cryoablation. Patients were excluded if they had multiple tumours, had received previous treatment of the tumour, or were treated with more than one cryoablation procedure. Pre- and post-treatment eGFR (within 3 months of the procedure) were compared. RESULTS: Of 222 patients with solitary kidneys entered into the database, a total of 70 patients met inclusion criteria. The mean baseline eGFR was 55.8 ± 16.8 mL/min/1.73 m2, and the mean 3-month post-operative eGFR was 49.6 ± 16.5 mL/min/1.73 m2. Mean eGFR reduction was - 6.2 mL/min/1.73 m2 corresponding to 11.1% (p = 0.01). No patients changed chronic kidney disease group to severe or end-stage chronic kidney disease (stage IV or V). No patients required post-procedure dialysis. CONCLUSION: Image-guided renal cryoablation appears to be safe and effective for renal function preservation in patients with RCC in a solitary kidney. Following cryoablation, all patients had preservation of renal function without the need for dialysis or progression in chronic kidney disease stage despite the statistically significant reduction in eGFR. LEVEL OF EVIDENCE 3: Observational study.

A National Study of the Rate of Benign Pathology After Partial Nephrectomy for T1 Renal Cell Carcinoma: Should We Be Satisfied?

Objectives: To determine the rate of benign pathology in cT1 tumors following partial nephrectomy in the Netherlands, thereby evaluating the rate of overtreatment. Methods: Data were collected from a nationwide database containing histopathology of resected renal tissue from 2014 to 2022. Patients who underwent partial nephrectomy for suspected RCC staged T1a-b were extracted for analysis. Data are shown in percentages, and multivariable logistic regression was performed to determine predictive factors for benign pathology. Results: 3409 cases were analyzed, of which 403 (12%) were benign and 3006 (88%) malignant. Subtype analysis showed 2126 (62%) cases of clear-cell RCC, followed by 604 (18%) of papillary RCC and 344 (10%) oncocytomas. Mean age was 63 years among patients with malignant pathology versus 65 years for patients with benign lesions (p < 0.001). Mean tumor size was 3.2 cm for malignant pathology and 2.9 cm for benign (p < 0.001). The rates of benign and malignant pathology did not change between 2014 and 2022 (p = 0.377). Multivariable regression showed age ≥ 65 years (65-79 years [OR 1.881, p = 0.002], ≥ 80 years [OR 3.642, p < 0.001]) and tumor size (OR 0.793, p < 0.001) as predictors for benign pathology. The main limitation of this study is that we do not know the biopsy rate of our cohort. Conclusion: This study reports a low rate of 12% benign pathology after partial nephrectomy in the Netherlands. It remains debatable whether these rates are acceptable, or if renal tumor biopsies should be utilized more frequently to reduce overtreatment.

Primary urethral carcinoma in females: an epidemiologic study on demographical factors, histological types, tumour stage and survival.

PURPOSE: To obtain insight into demographical factors, histology and survival rates of females diagnosed with primary urethral cancer and to determine favourable treatment. METHODS: Data from 91 females with primary urethral carcinoma, age varying from 15 to 85 years, registered between 1989 and 2008 at the National Cancer Registry of the Netherlands were used for this study. Demographical factors, incidence rate, morphology and tumour stage according to TNM classification were analysed. Kaplan-Meier survival curves were constructed and stratified by stage, histological type and treatment modality. RESULTS: The overall crude annual incidence was 0.7 per million women with a peak incidence in the age group of 80-84 years. Analysis of the morphology showed urothelial cell carcinoma (UCC) in 45 %, squamous cell carcinoma (SCC) in 19 %, adenocarcinoma (AC) in 29 %, and unknown or undifferentiated carcinoma accounted for 6 %. Almost half of patients (46 %) had advanced disease at time of diagnosis and was mainly treated with surgery and/or radiotherapy. The 5-year survival rates of stage 0-II, stage III and stage IV were 67, 53 and 17 %, respectively. The 5-year survival rates of SCC, UCC and AC were 64, 61 and 31 %, respectively. CONCLUSIONS: Female primary urethral carcinoma is a rare condition, and the majority of patients were aged above 65 years. Almost half of patients have advanced disease upon diagnosis. TNM stage and histological type of disease are the most determining factors for survival. Extended surgery with or without radiotherapy seems to be the most favourable treatment. Awareness and early diagnosis are important to improve survival.

Oncological and Peri-Operative Outcomes of Percutaneous Cryoablation of Renal Cell Carcinoma for Patients with Hereditary RCC Diseases-An Analysis of European Multi-Centre Prospective EuRECA Registry.

This study aims to evaluate the safety, efficacy, and renal function preservation of percutaneous cryoablation (PCA) for small renal masses (SRMs) in inherited RCC syndromes. Patients with inherited T1N0M0 RCCs (<7 cm) undergoing PCA from 2015 to 2021 were identified from the European Registry for Renal Cryoablation (EuRECA). The primary outcome was local recurrence-free survival (LRFS). The secondary outcomes included technical success, peri-operative outcomes, and other oncological outcomes estimated using the Kaplan-Meier method. Simple proportions, chi-squared tests, and t-tests were used to analyse the peri-operative outcomes. A total of 68 sessions of PCA were performed in 53 patients with RCC and 85 tumours were followed-up for a mean duration of 30.4 months (SD ± 22.0). The overall technical success rate was 99%. The major post-operative complication rate was 1.7%. In total, 7.4% (2/27) of patients had >25% reduction in renal function. All oncological events were observed in VHL patients. Estimated 5-year LRFS, metastasis-free survival, cancer-specific survival, and overall survival were 96.0% (95% CI 75-99%), 96.4% (95% CI 77-99%), 90.9% (95% CI 51-99%), and 90.9% (95% CI 51-99%), respectively. PCA of RCCs for patients with hereditary RCC SRMs appears to be safe, offers low complication rates, preserves renal function, and achieves good oncological outcomes.

Gradient changes in porcine renal arterial vascular anatomy and blood flow after cryoablation.

PURPOSE: We quantified temporal changes in vascular structure and blood flow after cryosurgery of the porcine kidney in vivo. MATERIALS AND METHODS: We studied 5 groups of 4 kidneys each with a survival time of 20 minutes, 4 hours, 2 days, and 1 and 2 weeks after cryoablation, respectively. Before harvesting the kidneys, fluorescently labeled microspheres were administrated in the descending aorta. After harvest the kidney and its vasculature were casted with fluorescently dyed elastomer, frozen and processed in an imaging cryomicrotome to reveal the 3-dimensional arterial branching structure and microsphere distribution. In regions of interest vessels were segmented by image analysis software and histograms were constructed to reveal the total summed vessel length as a function of diameter. A characteristic diameter of the ablated area was measured. RESULTS: The 20-minute survival group histograms showed a significant shift of the peak to larger diameters (p<0.002), indicating that smaller vessels were destroyed. Microsphere density was decreased to 2% in the ablated region but not in the nonablated border zone, depending on the remaining crater crossing larger vessels. After 2 weeks neither vessels nor microspheres were left in the ablated area, which had shrunk by about 40% in diameter. Study limitations are the lack of histological confirmation and the use of normal rather than cancerous tissue. CONCLUSIONS: Larger vessels remain patent just after ablation and transport blood to the border of the ablation crater but perfusion within the crater is halted instantly. Characteristic crater diameter increases initially but decreases thereafter. Destruction of vessels and tissue is complete 2 weeks after cryoablation.

Salvage Robot-assisted Renal Surgery for Local Recurrence After Surgical Resection or Renal Mass Ablation: Classification, Techniques, and Clinical Outcomes.

BACKGROUND: Salvage treatment for local recurrence after prior partial nephrectomy (PN) or local tumor ablation (LTA) for kidney cancer is, as of yet, poorly investigated. OBJECTIVE: To classify the treatments and standardize the nomenclature of salvage robot-assisted renal surgery, to describe the surgical technique for each scenario, and to investigate complications, renal function, and oncologic outcomes. DESIGN, SETTING, AND PARTICIPANTS: Sixty-seven patients underwent salvage robot-assisted renal surgery from October 2010 to December 2020 at nine tertiary referral centers. SURGICAL PROCEDURE: Salvage robot-assisted renal surgery classified according to treatment type as salvage robot-assisted partial or radical nephrectomy (sRAPN or sRARN) and according to previous primary treatment (PN or LTA). MEASUREMENTS: Postoperative complications, renal function, and oncologic outcomes were assessed. RESULTS AND LIMITATIONS: A total of 32 and 35 patients underwent salvage robotic surgery following PN and LTA, respectively. After prior PN, two patients underwent sRAPN, while ten underwent sRARN for a metachronous recurrence in the same kidney. No intra- or perioperative complication occurred. For local recurrence in the resection bed, six patients underwent sRAPN, while 14 underwent sRARN. For sRAPN, the intraoperative complication rate was 33%; there was no postoperative complication. For sRARN, there was no intraoperative complication and the postoperative complication rate was 7%. At 3 yr, the local recurrence-free rates were 64% and 82% for sRAPN and sRARN, respectively, while the 3-yr metastasis-free rates were 80% and 79%, respectively. At 33 mo, the median estimated glomerular filtration rates (eGFRs) were 57 and 45 ml/min/1.73 m2 for sRAPN and sRARN, respectively. After prior LTA, 35 patients underwent sRAPN and no patient underwent sRARN. There was no intraoperative complication; the overall postoperative complications rate was 20%. No local recurrence occurred. The 3-yr metastasis-free rate was 90%. At 43 mo, the median eGFR was 38 ml/min/1.73 m2. The main limitations are the relatively small population and the noncomparative design of the study. CONCLUSIONS: Salvage robot-assisted surgery has a safe complication profile in the hands of experienced surgeons at high-volume institutions, but the risk of local recurrence in this setting is non-negligible. PATIENT SUMMARY: Patients with local recurrence after partial nephrectomy or local tumor ablation should be aware that further treatment with robot-assisted surgery is not associated with a worrisome complication profile, but also that they are at risk of further recurrence.

Renal biopsies performed before versus during ablation of T1 renal tumors: implications for prevention of overtreatment and follow-up.

PURPOSE: To assess the difference between renal mass biopsy (RMB) performed either before or during the ablation procedure. METHODS: A retrospective multicenter study was performed in patients with a cT1 renal mass treated with ablation between January 2007 and July 2019, including a search in the national pathology database for patients with a RMB planned for ablation. Patient and tumor characteristics and information on malignant, benign, and non-diagnostic biopsy results were collected to establish rates of overtreatment and number of ablations avoided in case of benign or non-diagnostic histology. RESULTS: RMB was performed in 714 patients, of which 231 patients received biopsy before planned ablation, and 483 patients at the time of ablation. Pathology results before ablation were malignant in 63% (145/231), benign in 20% (46/231) and non-diagnostic in 17% (40/231). Pathology results at the time of ablation were malignant in 67.5% (326/483), benign in 16.8% (81/483) and non-diagnostic in 15.7% (76/483), leading to a total of 32.5% of ablation of benign or non-diagnostic lesions. Of the patients with a benign biopsy obtained before ablation, 80.4% (37/46) chose not to undergo ablation. Patients with inconclusive biopsy before planned ablation chose an informed individualized approach including ablation, repeated biopsy, or no intervention in 56%, 34% and 10%. CONCLUSION: This study emphasizes the importance of obtaining a biopsy prior to the ablation procedure in a separate session to lower the rate of potentially unnecessary ablations.

Immediate effect of kidney cryoablation on renal arterial structure in a porcine model studied by imaging cryomicrotome.

PURPOSE: Injury to blood microvessels has a crucial role in effective cryoablation for renal masses. We visualized vascular injury induced by a clinically applied cryoablation instrument and established a microvascular diameter threshold for vascular damage. MATERIALS AND METHODS: In 5 anesthetized pigs 1 kidney each was exposed and 3, 17 gauge cryoneedles were inserted in 1 pole. Tissue was exposed to freezing for 2 x 10 minutes with a 10-minute thaw between freezes. After nephrectomy the arteries were injected with fluorescence dyed casting material and the kidney was frozen to -20C and cut in 40 to 60 micron slices in the imaging cryomicrotome, where fluorescent images of the cutting plane of the bulk were obtained. This resulted in a 3-dimensional image of the arterial tree that was segmented, resulting in unbranched vessel segments. Histograms were constructed with the total segment length per diameter bin plotted as function of diameter. RESULTS: The ablated zone was sharply demarcated on fluorescent and normal light images. Mean +/- SD diameter at the peak of the histogram from control areas was 152.4 +/- 5.3 micron. Compared to control areas the peak diameter of ablated areas was shifted to a larger diameter by an average of 25.4 +/- 2.6 micron. CONCLUSIONS: Immediate renal cryoablation injury destroys arteries smaller than 180 micron. Branching structures of larger arteries remain anatomically intact and connected to vascular structures in surrounding tissue.

Renal Function Loss After Cryoablation of Small Renal Masses in Solitary Kidneys: European Registry for Renal Cryoablation Multi-Institutional Study.

Objectives: To estimate and quantify the loss of kidney function in solitary kidneys with small renal masses (SRMs) after laparoscopy-assisted renal cryoablation (LARC), from the European Registry for Renal Cryoablation (EuRECA) database. Patients and Methods: Of the 808 patients from eight European centers in the database, 102 patients had SRMs in solitary kidneys. Patient demographics, body mass index (BMI), American Society of Anesthesiologists (ASA) grade, Charlson comorbidity index, and tumor characteristics including nephrometry (PADUA) score where available were collected. Renal function data in the form of estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) stratification both preoperatively and at 3 months postoperatively were collected. Results: The median (interquartile range [IQR]) age was 67 (59-81) years, the median (IQR) BMI was 26 (23.9-28.9) kg/m2, and the median (IQR) ASA score was 2 (2-3). The median Charlson score was 4 (range: 0-10). The median (IQR) tumor size in cross-sectional imaging was 26 (19-38) mm. The follow-up data were available for 72 patients with a median follow-up for this group of 38 (range: 10-132) months. The mean preoperative eGFR was 55.0 mL/minute/1.73 m2 (standard deviation [SD] = 18.1), and the mean postoperative eGFR was 51.8 mL/minute/1.73 m2 (SD = 18.8). The change was -3.1 mL/minute/1.73 m2 (95% confidence interval -5.2 to -1.0) units, which was statistically significant (p = 0.004). The change in the CKD stages comparing before and after LARC was not significant (paired two-tailed t-test, p = 0.06). Critically, the decrease in the eGFR did not translate to any significant adverse outcome and zero patients required dialysis. Conclusion: To the best of our knowledge, this is the largest study of renal function after LARC in SRMs in solitary kidneys. Cryotherapy in this imperative situation is safe, carries clinically insignificant reduction in renal function, therefore providing an option to minimize the risk of developing renal failure necessitating dialysis.