Identifying the facilitators and barriers to implementation of renal tumour biopsy in the diagnostic pathway for small renal masses.

OBJECTIVES: To understand the facilitators and barriers to the implementation of renal tumour biopsy (RTB) in the diagnostic pathway for renal tumours in England. PATIENTS AND METHODS: Participants consisted of patients who had a renal tumour diagnosed and/or treated at one of five tertiary centres in England, healthcare professionals involved in the direct care of patients diagnosed with renal tumours, and clinical service managers and commissioners. The study employed a mixed-methods research methodology consisting of individual interviews and an on-line survey that explored the types of facilitators and barriers individuals perceived and experienced and the frequency in which these were reported. A public dissemination event took place following the completion of data collection; to facilitate discussion of potential solutions to implementing RTB. RESULTS: There were 50 participant interviews (23 patients, 22 clinicians, and five health service commissioners/operations managers). The patient on-line survey received 52 responses, and the clinician survey received 22 responses. Patients most frequently reported influences in choosing whether to undergo RTB pertained to wanting to know the diagnosis of their kidney mass (40%), the advice or information provided by healthcare professionals (40%), and not wishing to delay treatment (23%). Clinicians most frequently reported barriers to recommending RTB related to their uncertainty of diagnostic accuracy (56%), availability of appointments or hospital beds (52%), concerns of risk of bleeding (44%), risk of seeding (41%), and delays in meeting national cancer pathway targets (41%). The dissemination event was attended by 18 participants (seven patients and 11 clinicians). Suggestions to improve implementation included reducing variation and promotion of standardisation of practice by a consensus statement, increasing the evidence base (clinicians) and improved communication by developing better patient aids such as videos and diagrams (patients and clinicians). CONCLUSION: Implementation of RTB may be dependent on the quality of information provided, its format and perceived reliability of the information. Increased utilisation of RTB may be improved by development of a consensus statement on the role of biopsy, with patients expressing a preference for alternative information aids such as patient videos.

Not-so-simple nephrectomy: Comparative analysis of radical and simple nephrectomy in a high-volume tertiary referral center.

OBJECTIVES: Simple nephrectomies can be challenging with significant morbidity. To prove the hypothesis of "not-so-simple" nephrectomy, we compared demographics, perioperative outcomes, and complications between simple and radical nephrectomy in a tertiary referral center. METHODS: We analyzed 473 consecutive radical nephrectomies (January 2018-October 2020) and simple nephrectomies (January 2016-October 2020). Univariate and multivariate analysis of perioperative outcomes utilized the Mann-Whitney U test, Chi-squared test, Mantel-Haenszel test of trend, and multiple linear regression. Radical nephrectomies were classified in cT1, cT2a, and cT2b-T3 subgroups and compared to simple nephrectomies. Minimally invasive and open techniques were compared between the two groups. Infected versus non-infected simple nephrectomies were compared. RESULTS: A total of 344 radical and 129 simple nephrectomies were included. Simple nephrectomy was an independent predictor of increased operative time (p = 0.001), length of stay (p = 0.049), and postoperative complications (p < 0.001). Simple nephrectomies had higher operative time (p < 0.001), length of stay (p = 0.014), and postoperative morbidity (p < 0.001) than cT1 radical nephrectomies and significantly more Clavien 1-2 complications than cT2a radical nephrectomies (p = 0.001). The trend was similar in minimally invasive operations. However, conversion to open rates was not significantly different. Infected simple nephrectomies had increased operative time (p < 0.001), length of stay (p = 0.005), blood loss (p = 0.016), and intensive care stay (p = 0.019). CONCLUSIONS: Patients undergoing simple nephrectomy experienced increased operative time and morbidity. Simple nephrectomy carries higher morbidity than radical nephrectomy in tumors ≤10 cm. Robotic simple nephrectomies may reduce open conversion rates. Postoperative intensive care and enhanced recovery may be essential in simple nephrectomy planning with infected pathology.

The Current Evidence for Factors that Influence Treatment Decision Making in Localized Kidney Cancer: A Mixed Methods Systematic Review.

PURPOSE: With a growing number of treatment options for localized kidney cancer, patients and health care professionals have both the opportunity and the burden of selecting the most suitable management option. This mixed method systematic review aims to understand the barriers and facilitators of the treatment decision making process in localized kidney cancer. MATERIALS AND METHODS: We searched PubMed®, Embase® and Cochrane Central databases between January 1, 2004 and April 23, 2020 using the Joanna Briggs Manual for Evidence Synthesis and the Preferred Reporting Items for Systematic Review and Meta-analysis statement. We identified 553 unique citations; of these, 511 were excluded resulting in 42 articles included for synthesis. The Purpose, Respondents, Explanation, Findings and Significance and the Strengthening the Reporting of Observational Studies in Epidemiology checklist was applied. RESULTS: The key themes describing barriers and facilitators to treatment decision making were identified and categorized into 3 domains: 1) kidney cancer specific characteristics, 2) decision maker related criteria and 3) contextual factors. The main facilitators identified within these domains were size at diagnosis, age, comorbidities, body mass index, gender, nephrometry scoring systems, biopsy, socioeconomic status, family history of cancer, year of diagnosis, geographic region and practice pattern. The key barriers were race, gender, patient anxiety, low confidence in diagnostic and treatment options, cost of procedure, and practice patterns. CONCLUSIONS: Future interventions designed to improve the decision making process for localized kidney cancer should consider these barriers and facilitators to ensure a better patient experience.

Impact of the first surge of the COVID-19 pandemic on a tertiary referral centre for kidney cancer.

OBJECTIVE: To analyse the impact of the COVID-19 pandemic on a centralized specialist kidney cancer care pathway. MATERIALS AND METHODS: We conducted a retrospective analysis of patient and pathway characteristics including prioritization strategies at the Specialist Centre for Kidney Cancer located at the Royal Free London NHS Foundation Trust (RFH) before and during the surge of COVID-19. RESULTS: On 18 March 2020 all elective surgery was halted at RFH to redeploy resources and staff for the COVID-19 surge. Prioritizing of patients according to European Association of Urology guidance was introduced. Clinics and the specialist multidisciplinary team (SMDT) meetings were maintained with physical distancing, kidney surgery was moved to a COVID-protected site, and infection prevention measurements were enforced. During the 7 weeks of lockdown (23 March to 10 May 2020), 234 cases were discussed at the SMDT meetings, 53% compared to the 446 cases discussed in the 7 weeks pre-lockdown. The reduction in referrals was more pronounced for small and asymptomatic renal masses. Of 62 low-priority cancer patients, 27 (43.5%) were deferred. Only one (4%) COVID-19 infection occurred postoperatively, and the patient made a full recovery. No increase in clinical or pathological upstaging could be detected in patients who underwent deferred surgery compared to pre-COVID practice. CONCLUSION: The first surge of the COVID-19 pandemic severely impacted diagnosis, referral and treatment of kidney cancer at a tertiary referral centre. With a policy of prioritization and COVID-protected pathways, capacity for time-sensitive oncological interventions was maintained and no immediate clinical harm was observed.

Growth and renal function dynamics of renal oncocytomas in patients on active surveillance.

OBJECTIVES: To study the natural history of renal oncocytomas and address indications for intervention by determining how growth is associated with renal function over time, the reasons for surgery and ablation, and disease-specific survival. PATIENTS AND METHODS: The study was conducted in a retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at the Royal Free London NHS Foundation Trust (2012 to 2019). Comparison between groups was performed using Mann-Whitney U-tests and chi-squared tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR). RESULTS: Longitudinal data from 98 patients with 101 lesions were analysed. Most patients were men (68.3%) and the median (interquartile range [IQR]) age was 69 (13) years. The median (IQR) follow-up was 29 (26) months. Most lesions were small renal masses, and 24% measured over 4 cm. Over half (64.4%) grew at a median (IQR) rate of 2 (4) mm per year. No association was observed between tumour size and eGFR over time (P = 0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma. CONCLUSION: Natural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow-up of over 2 years. Active surveillance should be considered the 'gold standard' management of renal oncocytomas up to 7cm.

Robot-assisted kidney transplantation: update from the European Robotic Urology Section (ERUS) series.

OBJECTIVE: To report the results of the robot-assisted kidney transplantation (RAKT) experience performed in 10 European centres by members of the European Robotic Urology Section (ERUS)-RAKT group. PATIENTS AND METHODS: This is a multicentre prospective observational study of RAKT. Descriptive analysis of recipients and donor characteristics, surgical data, intraoperative outcomes, complications rate and functional results were collected and analysed. RESULTS: Between July 2015 and September 2019, 291 living-donor RAKTs were performed. Recipients were mostly male (189 [65%]), the mean Standard deviation (sd) age was 45.2 (13.35) years, the mean (sd) body mass index was 27.13 (19.28) kg/m2 , and RAKT was pre-emptive in 155 (53.8%) cases. Right and multiple arteries kidneys were used in 15.4%. The mean (sd) total surgical and re-warming time was 244 (70.5) min and 53.16 (15.27) min, respectively. In all, 17 patients presented with postoperative bleeding (5.7%). Five kidneys had delayed graft function; five (2%) were lost due to thrombosis and one due to acute rejection. Two patients had arterial stenosis, three had incisional hernias, six had ureteric stenosis, and nine had lymphoceles. Neither surgical nor re-warming times were correlated with postoperative serum creatinine levels (P > 0.05). Comparison of surgical data between the first 120 cases and the following 171 cases showed a significantly shorter total surgical time in the second group (265 vs 230 min, P = 0.005). CONCLUSIONS: This is the largest European multicentre study of RAKT with good surgical and functional results competitive with open kidney transplant series, with a relatively short learning curve when performed in centres with a wide experience in open kidney transplantation and robotic surgery.

Pattern, timing and predictors of recurrence after surgical resection of chromophobe renal cell carcinoma.

PURPOSE: Currently there are no specific guidelines for the post-operative follow-up of chromophobe renal cell carcinoma (chRCC). We aimed to evaluate the pattern, location and timing of recurrence after surgery for non-metastatic chRCC and establish predictors of recurrence and cancer-specific death. METHODS: Retrospective analysis of consecutive surgically treated non-metastatic chRCC cases from the Royal Free London NHS Foundation Trust (UK, 2015-2019) and the international collaborative database RECUR (15 institutes, 2006-2011). Kaplan-Meier curves were plotted. The association between variables of interest and outcomes were analysed using univariate and multivariate Cox proportional hazards regression models with shared frailty for data source. RESULTS: 295 patients were identified. Median follow-up was 58 months. The five and ten-year recurrence-free survival rates were 94.3% and 89.2%. Seventeen patients (5.7%) developed recurrent disease, 13 (76.5%) with distant metastases. 54% of metastatic disease diagnoses involved a single organ, most commonly the bone. Early recurrence (< 24 months) was observed in 8 cases, all staged ≥ pT2b. 30 deaths occurred, of which 11 were attributed to chRCC. Sarcomatoid differentiation was rare (n = 4) but associated with recurrence and cancer-specific death on univariate analysis. On multivariate analysis, UICC/AJCC T-stage ≥ pT2b, presence of coagulative necrosis, and positive surgical margins were predictors of recurrence and cancer-specific death. CONCLUSION: Recurrence and death after surgically resected chRCC are rare. For completely excised lesions ≤ pT2a without coagulative necrosis or sarcomatoid features, prognosis is excellent. These patients should be reassured and follow-up intensity curtailed.

Safety and feasibility of early single-dose mitomycin C bladder instillation after robot-assisted radical nephroureterectomy.

OBJECTIVES: To assess the safety and feasibility of early single-dose mitomycin C (MMC) bladder instillation after robot-assisted radical nephroureterectomy (RARNU) at a tertiary kidney cancer centre. RARNU with bladder cuff excision and subsequent MMC bladder instillation to reduce recurrence risk is the 'gold standard' for high-risk upper urinary tract urothelial carcinoma (UUTUC). We adapted a RARNU technique with precise distal ureteric dissection, bladder cuff excision and watertight bladder closure. PATIENTS AND METHODS: We retrospectively reviewed all patients undergoing RARNU for UUTUC at our centre performed as a standardised transperitoneal procedure comprising of: bladder cuff excision, two-layer watertight closure and intraoperative bladder leak test; without re-docking/re-positioning of the robotic surgical system. Patient demographics, the timing of MMC instillation, adverse events (surgical and potentially MMC-related) and length of stay (LOS) were assessed according to the Clavien-Dindo classification. RESULTS: A total of 69 patients underwent a RARNU with instillation of MMC. The median (interquartile range [IQR]) age was 70 (62-78) years. The median (IQR) day of MMC instillation was 2 (1-3) days and the median (IQR) LOS was 2 (2-4) days, with urethral catheter removal on day of discharge in all cases. Only Grade I Clavien-Dindo complications occurred in seven patients (10%); five had ileus, one a wound infection and one a self-limiting delirium, all managed conservatively. No adverse events potentially related to MMC instillation were noted within 30 days postoperatively. CONCLUSION: The use of intravesical MMC instillation given in the immediate postoperative period appears feasible and safe in patients undergoing RARNU with intraoperative confirmation of a water-tight closure ensuring early catheter-free discharge, with no significant adverse events. The potential reduction in intravesical recurrence in patients receiving early MMC needs to be assessed with longitudinal follow-up studies.

Guideline adherence for the surgical treatment of T1 renal tumours correlates with hospital volume: an analysis from the British Association of Urological Surgeons Nephrectomy Audit.

OBJECTIVE: To assess European Association of Urology guideline adherence on the surgical management of patients with T1 renal tumours and the effects of centralisation of care. PATIENTS AND METHODS: Retrospective data from all kidney tumours that underwent radical nephrectomy (RN) or partial nephrectomy (PN) in the period 2012-2016 from the British Association of Urological Surgeons Nephrectomy Audit were retrieved and analysed. We assessed total surgical hospital volume (HV; RN and PN performed) per centre, PN rates, complication rates, and completeness of data. Descriptive analyses were performed, and confidence intervals were used to illustrate the association between hospital volume and proportion of PN. Chi- squared and Cochran-Armitage trend tests were used to evaluate differences and trends. RESULTS: In total, 13 045 surgically treated T1 tumours were included in the analyses. Over time, there was an increase in PN use (39.7% in 2012 to 44.9% in 2016). Registration of the Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) complexity score was included in March 2016 and documented in 39% of cases. Missing information on postoperative complications appeared constant over the years (8.5-9%).  A clear association was found between annual HV and the proportion of T1 tumours treated with PN rather than RN (from 18.1% in centres performing <25 cases/year [lowest volume] to 61.8% in centres performing ≥100 cases/year [high volume]), which persisted after adjustment for PADUA complexity. Overall and major (Clavien-Dindo grade ≥III) complication rate decreased with increasing HV (from 12.2% and 2.9% in low-volume centres to 10.7% and 2.2% in high-volume centres, respectively), for all patients including those treated with PN. CONCLUSION: Closer guideline adherence was exhibited by higher surgical volume centres. Treatment of T1 tumours using PN increased with increasing HV, and was accompanied by an inverse association of HV with complication rate. These results support the centralisation of kidney cancer specialist cancer surgical services to improve patient outcomes.

Comprehensive training in robotic surgery.

PURPOSE OF REVIEW: Robotic training in urology can be poorly structured, lack a basic skills foundation, and may not include teaching in important nontechnical human factor skills vital to the safe delivery of robotic care. Assessment of acquired skills is not routine. There is a need for structured and standardized curricular to deliver validated training and final assessment. The present reviews the current literature on training methods for robotic surgery, and examines the evidence for their effect on performance, where available. RECENT FINDINGS: There is good evidence for the beneficial effect of dry lab simulators on robotic skills acquisition, but less for cadaveric and animal models. Two urological authorities have developed comprehensive curricula for robotic training that take a novice robotic surgeon through the full stages of robotic skills acquisition. These are in the early stages of development and validation but have stimulated the development of curricula in other specialties. SUMMARY: The future landscape for robotic urology training is likely to include structured, mandated, and centralized training, possibly administered by urological organizations. There will be roles for telementoring, advanced education for robotic trainers, and regular revalidation of expert robotic surgeons.

Contemporary surgical management of renal oncocytoma: a nation's outcome.

OBJECTIVE: To report on the contemporary UK experience of surgical management of renal oncocytomas. PATIENTS AND METHODS: Descriptive analysis of practice and postoperative outcomes of patients with a final histological diagnosis of oncocytoma included in The British Association of Urological Surgeons (BAUS) nephrectomy registry from 01/01/2013 to 31/12/2016. Short-term outcomes were assessed over a follow-up of 60 days. RESULTS: Over 4 years, 32 130 renal surgical cases were recorded in the UK, of which 1202 were oncocytomas (3.7%). Most patients were male (756; 62.9%), the median (interquartile range [IQR]) age was 66.8 (13) years. The median (IQR; range) lesion size was 4.1 (3; 1-25) cm, 43.5% were ≤4 cm and 30.3% were 4-7 cm lesions. In all, 35 patients (2.9%) had preoperative renal tumour biopsy. Most patients had minimally invasive surgery, either radical nephrectomy (683 patients; 56.8%), partial nephrectomy (483; 40.2%) or other procedures (36; 3%). One in five patients (243 patients; 20.2%) had in-hospital complications: 48 were Clavien-Dindo classification grade ≥III (4% of the total cohort), including three deaths. Two additional deaths occurred within 60 days of surgery. The analysis is limited by the study's observational nature, not capturing lesions on surveillance or ablated after biopsy, possible underreporting, short follow-up, and lack of central histology review. CONCLUSION: We report on the largest surgical series of renal oncocytomas. In the UK, the complication rate associated with surgical removal of a renal oncocytoma was not negligible. Centralisation of specialist services and increased utilisation of biopsy may inform management, reduce overtreatment, and change patient outcomes for this benign tumour.

Renal cell tumors with clear cell histology and intact VHL and chromosome 3p: a histological review of tumors from the Cancer Genome Atlas database.

Clear cell renal cell carcinoma is by far the most common form of kidney cancer; however, a number of histologically similar tumors are now recognized and considered distinct entities. The Cancer Genome Atlas published data set was queried (http://cbioportal.org) for clear cell renal cell carcinoma tumors lacking VHL gene mutation and chromosome 3p loss, for which whole-slide images were reviewed. Of the 418 tumors in the published Cancer Genome Atlas clear cell renal cell carcinoma database, 387 had VHL mutation, copy number loss for chromosome 3p, or both (93%). Of the remaining, 27/31 had whole-slide images for review. One had 3p loss based on karyotype but not sequencing, and three demonstrated VHL promoter hypermethylation. Nine could be reclassified as distinct or emerging entities: translocation renal cell carcinoma (n=3), TCEB1 mutant renal cell carcinoma (n=3), papillary renal cell carcinoma (n=2), and clear cell papillary renal cell carcinoma (n=1). Of the remaining, 6 had other clear cell renal cell carcinoma-associated gene alterations (PBRM1, SMARCA4, BAP1, SETD2), leaving 11 specimens, including 2 high-grade or sarcomatoid renal cell carcinomas and 2 with prominent fibromuscular stroma (not TCEB1 mutant). One of the remaining tumors exhibited gain of chromosome 7 but lacked histological features of papillary renal cell carcinoma. Two tumors previously reported to harbor TFE3 gene fusions also exhibited VHL mutation, chromosome 3p loss, and morphology indistinguishable from clear cell renal cell carcinoma, the significance of which is uncertain. In summary, almost all clear cell renal cell carcinomas harbor VHL mutation, 3p copy number loss, or both. Of tumors with clear cell histology that lack these alterations, a subset can now be reclassified as other entities. Further study will determine whether additional entities exist, based on distinct genetic pathways that may have implications for treatment.

Surgical and Minimally Invasive Therapies for the Management of the Small Renal Mass.

PURPOSE OF REVIEW: This article aims to summarise recent developments in surgical and minimally invasive therapies in the management of small renal masses (SRMs). RECENT FINDINGS: The incidence of the small renal mass is increasing. Standard management of the SRM is partial nephrectomy. More recently, use of ablative techniques to manage the SRM has been increasing and an exciting array of technical advances is currently being made in the field. Nephron-sparing surgery looks set to become more financially viable with the advent of newer robotic platforms and, potentially, even less invasive with the evaluation of single-port access. Real-time imaging promises to improve tumour definition, nephron preservation and vascular management intraoperatively. Advances in surgical and minimally invasive therapies for the management of the SRM have the potential to improve cancer clearance and long-term renal function preservation. Patients will experience safer, more reliable and less invasive treatments for their small renal tumours. We describe the current advances underlying these changes.

Multicentre outcomes of robot-assisted partial nephrectomy after major open abdominal surgery.

OBJECTIVE: To evaluate the outcomes of robot-assisted partial nephrectomy RAPN after major prior abdominal surgery (PAS) using a large multicentre database. PATIENTS AND METHODS: We identified 1 686 RAPN from five academic centres between 2006 and 2014. In all, 216 patients had previously undergone major PAS, defined as having an open upper midline/ipsilateral incision. Perioperative outcomes were compared with those 1 470 patients who had had no major PAS. The chi-squared test and Mann-Whitney U-test were used for categorical and continuous variables, respectively. RESULTS: There was no statistically significant difference in Charlson comorbidity index, tumour size, R.E.N.A.L. nephrometry score or preoperative estimated glomerular filtration rate (eGFR) between the groups. Age and body mass index were higher in patients with PAS. The PAS group had a higher estimated blood loss (EBL) but this did not lead to a higher transfusion rate. A retroperitoneal approach was used more often in patients with major PAS (11.2 vs 5.4%), although this group did not have a higher percentage of posterior tumours (38.8 vs 43.3%, P = 0.286). Operative time, warm ischaemia time, length of stay, positive surgical margin, percentage change in eGFR, and perioperative complications were not significantly different between the groups. CONCLUSIONS: RAPN in patients with major PAS is safe and feasible, with increased EBL but no increased rate of transfusion. Patients with major PAS had almost twice the likelihood of having a retroperitoneal approach.

Urinary fistula after robot-assisted partial nephrectomy: a multicentre analysis of 1 791 patients.

OBJECTIVE: To evaluate the incidence of and risk factors for a urine leak in a large multicentre, prospective database of robot-assisted partial nephrectomy (RPN). PATIENTS AND METHODS: A database of 1 791 RPN from five USA centres was reviewed for urine leak as a complication of RPN. Patient and tumour characteristics were compared between patients with and those without postoperative urine leaks. Fisher's exact test was used for qualitative variables and Wilcoxon sum-rank tests were used for quantitative variables. A review of the literature on PN and urine leak was conducted. RESULTS: Urine leak was noted in 14/1 791 (0.78%) patients who underwent RPN. The mean (sd) nephrometry score of the entire cohort was 7.2 (1.9), and 8.0 (1.9) in patients who developed urine leak. The median (range) postoperative day of presentation was 13 (3-32) days. Patients with urine leak presented in delayed fashion with fever (two of the 14 patients, 14%), gastrointestinal complaints (four patients, 29%), and pain (five patients, 36%). Eight of the 14 patients (57%) required admission, while eight (57%) and nine (64%) had a drain or stent placed, respectively. Drains and stents were removed after a median (range) of 8 (4-13) days and 21 (8-83) days, respectively. Variables associated with urine leak included tumour size (P = 0.021), hilar location (P = 0.025), operative time (P = 0.006), warm ischaemia time (P = 0.005), and pelvicalyceal repair (P = 0.018). Upon literature review, the historical incidence of urine leak ranged from 1.0% to 17.4% for open PN and 1.6-16.5% for laparoscopic PN. CONCLUSION: The incidence of urine leak after RPN is very low and may be predicted by some preoperative factors, affording better patient counselling of risks. The low urinary leak rate may be attributed to the enhanced visualisation and suturing technique that accompanies the robotic approach.

Robot-assisted hepatic mobilization and control of suprahepatic infradiaphragmatic inferior vena cava for level 3 vena caval thrombectomy: An IDEAL stage 0 study.

Robot-assisted level 1/2 inferior vena caval (IVC) thrombectomy techniques have been recently described for clinical use. Following the IDEAL recommendations on safe surgical innovation, we here describe a robotic approach for level 3 IVC thrombectomy in fresh frozen cadavers (IDEAL stage 0). In all cadavers (n = 3), hepatic mobilization with control of short hepatic veins, contralateral renal vein, infrarenal IVC and suprahepatic-infradiaphragmatic IVC could be achieved successfully, without converting to open surgery. Clinical feasibility of our technique remains to be tested.

Renal mass biopsy - a practical and clinicopathologically relevant approach to diagnosis.

Advancements in imaging modalities have increased the frequency of renal mass discovery. Imaging has typically been considered sufficient to guide management for a large proportion of these tumours, but renal mass biopsies (RMBs) have an increasing role in determining malignancy and can be a valuable tool for preventing unnecessary surgery in patients with benign tumours. A structured approach should be used to help to navigate the expanding repertoire of renal tumours, many of which are molecularly defined. In terms of tumour subtyping, the pathologist's strategy should focus on stratifying patients into clinically different prognostic groups according to our current knowledge of tumour behaviour, including benign, low-grade or indolent, intermediate malignant or highly aggressive. Crucial pathological features and morphological mimicry of tumours can alter the tumour's prognostic group. Thus, pathologists and urologists can use RMB to select patients with tumours at a reduced risk of progression, which can be safely managed with active surveillance within a tailored imaging schedule, versus tumours for which ablation or surgical intervention is indicated. RMB is also crucial in the oncological setting to distinguish between different high-grade tumours and guide tailored management strategies.

Nephron Sparing Treatment (NEST) for Small Renal Masses: A Feasibility Cohort-embedded Randomised Controlled Trial Comparing Percutaneous Cryoablation and Robot-assisted Partial Nephrectomy.

There is a paucity of high-level evidence on small renal mass (SRM) management, as previous classical randomised controlled trials (RCTs) failed to meet accrual targets. Our objective was to assess the feasibility of recruitment to a cohort-embedded RCT comparing cryoablation (CRA) to robotic partial nephrectomy (RPN). A total of 200 participants were recruited to the cohort, of whom 50 were enrolled in the RCT. In the CRA intervention arm, 84% consented (95% confidence interval [CI] 64-95%) and 76% (95% CI 55-91%) received CRA; 100% (95% CI 86-100%) of the control arm underwent RPN. The retention rate was 90% (95% CI 79-96%) at 6 mo. In the RPN group 2/25 (8%) were converted intra-operative to radical nephrectomy. Postoperative complications (Clavien-Dindo grade 1-2) occurred in 12% of the CRA group and 29% of the RPN group. The median length of hospital stay was shorter for CRA (1 vs 2 d; p = 0.019). At 6 mo, the mean change in renal function was -5.0 ml/min/1.73 m2 after CRA and -5.8 ml/min/1.73 m2 after RPN. This study demonstrates the feasibility of a cohort-embedded RCT comparing CRA and RPN. These data can be used to inform multicentre trials on SRM management. PATIENT SUMMARY: We assessed whether patients with a small kidney tumour would consent to a trial comparing two different treatments: cryoablation (passing small needles through the skin to freeze the kidney tumour) and surgery to remove part of the kidney. We found that most patients agreed and a full trial would therefore be feasible.