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. Summary: 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

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

Robot-assisted surgery in horseshoe kidneys: A safety and feasibility multi-centre case series

OBJECTIVE: We assessed the safety and feasibility of minimally invasive robot-assisted surgery for horseshoe kidney (HSK). METHOD: A prospectively maintained data set for consecutive patients undergoing robotic kidney surgery was reviewed for patients with HSK. Cases were performed by experienced robotic surgeons, across two high-volume centres between 2016 and 2020. RESULTS: A prospectively maintained data set for consecutive patients undergoing robotic kidney surgery was reviewed for patients with HSK. Cases were performed by experienced robotic surgeons, across two high-volume centres between 2016 and 2020. CONCLUSION: We report one the largest series of robot-assisted surgery on HSK. Robotic surgery is safe and feasible for HSK in centralised high-volume centres with acceptable perioperative outcomes. Established benefits of minimally invasive surgery, such as reduced LOS and low complication rates, were demonstrated. LEVEL OF EVIDENCE: 4

Interactive virtual 3D image reconstruction to assist renal surgery in patients with fusion anomalies of the kidney

Objective: Renal fusion anomalies are rare and usually present as horseshoe kidneys or crossed fusion ectopia. The complex renal anatomy seen in patients with these anomalies can present a challenge. Pre-operative planning is therefore paramount in the surgical management of these cases. Herein we report the use of interactive virtual three-dimensional (3D) reconstruction to aid renal surgery in patients with fusion anomalies of the kidney. / Materials and Methods: A total of seven cases were performed between May 2016 and October 2020. 3D reconstruction was rendered by Innersight Labs using pre-operative computed tomography (CT) scans. / Results: Five patients had malignant disease and two patients had benign pathology. Robotic and open operations were performed in four and three patients, respectively. / Conclusion: The use of 3D reconstruction in the cases reported in this series allowed for the identification of variations in renal vasculature, and this informed the choice of operative approach. / Oxford Centre for Evidence-Based Medicine Evidence Level: 4

Growth and renal function dynamics of renal oncocytomas 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

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

OBJECTIVES: To report on the contemporary UK experience of surgical management of renal oncocytomas. SUBJECTS AND METHODS: Descriptive analysis of practice and postoperative outcomes of cases 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 30 days. RESULTS: Over 4 years, 32130 renal surgical cases were recorded in the UK, of which 1202 were oncocytomas (3.7%). Most patients were male (n=756; 63.3%), the median age was 66.8 years (interquartile range (IQR) 13). Median lesion size was 4.1cm (IQR 3; range 1-25cm), 43.5% were ≤4cm and 34.2% were 4 to 7cm lesions. Thirty-five patients (2.9%) had preoperative renal tumour biopsy. The majority of patients had minimally invasive surgery, either radical (n=683; 56.8%), partial nephrectomy (n=483; 40.2%) or other procedures (n=36; 3%). One in five (n=253; 20.2%) patients had in-hospital complications: 48 were Clavien-Dindo classification grade III or above (4% of total cohort), including 3 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. This article is protected by copyright. All rights reserved

Protocol for a feasibility study of a cohort embedded randomised controlled trial comparing NEphron Sparing Treatment (NEST) for small renal masses

Introduction: Small renal masses (SRMs; ≤4 cm) account for two-thirds of new diagnoses of kidney cancer, the majority of which are incidental findings. The natural history of the SRM seems largely indolent. There is an increasing concern regarding surgical overtreatment and the associated health burden in terms of morbidity and economy. Observational data support the safety and efficacy of percutaneous cryoablation but there is an unmet need for high-quality evidence on non-surgical management options and a head-to-head comparison with standard of care is lacking. Historical interventional trial recruitment difficulties demand novel study conduct approaches. We aim to assess if a novel trial design, the cohort embedded randomised controlled trial (RCT), will enable carrying out such a comparison. / Methods and analysis: Single-centre prospective cohort study of adults diagnosed with SRM (n=200) with an open label embedded interventional RCT comparing nephron sparing interventions. Cohort participants will be managed at patient and clinicians’ discretion and agree with longitudinal clinical data and biological sample collection, with invitation for trial interventions and participation in comparator control groups. Cohort participants with biopsy-proven renal cell carcinoma eligible for both percutaneous cryoablation and partial nephrectomy will be randomly selected (1:1) and invited to consider percutaneous cryoablation (n=25). The comparator group will be robotic partial nephrectomy (n=25). The primary outcome of this feasibility study is participant recruitment. Qualitative research techniques will assess barriers and recruitment improvement opportunities. Secondary outcomes are participant trial retention, health-related quality of life, treatment complications, blood transfusion rate, intensive care unit admission and renal replacement requirement rates, length of hospital stay, time to return to pre-treatment activities, number of work days lost, and health technologies costs. / Ethics and dissemination: Ethical approval has been granted (UK HRA REC 19/EM/0004). Study outputs will be presented and published. / Trial registration: ISRCTN18156881; Pre-results

Diagnostic criteria for oncocytic renal neoplasms:a survey of urologic pathologists

Renal oncocytoma and chromophobe renal cell carcinoma (RCC) have been long recognized as distinct tumors; however, it remains unknown if uniform diagnostic criteria are used to distinguish these tumor types in practice. A survey was distributed to urologic pathologists regarding oncocytic tumors. Responses were received from 17/26 invitees. Histologically, >1 mitotic figure was regarded as most worrisome (n=10) or incompatible (n=6) with oncocytoma diagnosis. Interpretation of focal nuclear wrinkling, focal perinuclear clearing, and multinucleation depended on extent and did not necessarily exclude oncocytoma if minor. Staining techniques most commonly used included: CK7 (94%), KIT (71%), vimentin (65%), colloidal iron (59%), CD10 (53%), and AMACR (41%). Rare CK7-positive cells (≤5%) was regarded as most supportive of oncocytoma, although an extent excluding oncocytoma was not universal. Multiple chromosomal losses were most strongly supportive for chromophobe RCC diagnosis (65%). Less certainty was reported for chromosomal gain or a single loss. For tumors with mixed or inconclusive features, many participants use an intermediate diagnostic category (82%) that does not label the tumor as unequivocally benign or malignant, typically "oncocytic neoplasm" or "tumor" with comment. The term "hybrid tumor" was used variably in several scenarios. A slight majority (65%) report outright diagnosis of oncocytoma in needle biopsies. The morphologic, immunohistochemical, and genetic characteristics that define oncocytic renal tumors remain incompletely understood. Further studies correlating genetics, behavior, and histology are needed to define which tumors truly warrant classification as carcinomas for patient counseling and follow-up strategies

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease