Evaluating the Efficacy of AI Chatbots as Tutors in Urology: A Comparative Analysis of Responses to the 2022 In-Service Assessment of the European Board of Urology.

INTRODUCTION: This study assessed the potential of Large Language Models (LLMs) as educational tools by evaluating their accuracy in answering questions across urological subtopics. METHODS: Three LLMs (ChatGPT-3.5, ChatGPT-4, and Bing AI) were examined in two testing rounds, separated by 48-hours, using 100 Multiple-Choice Questions (MCQs) from the 2022 European Board of Urology (EBU) In-Service Assessment (ISA), covering five different subtopics. The correct answer was defined as "formal accuracy" (FA) representing the designated single best answer (SBA) among four options. Alternative answers selected from LLMs, which may not necessarily be the SBA but are still deemed correct, were labeled as "extended accuracy" (EA). Their capacity to enhance the overall accuracy rate when combined with FA was examined. RESULTS: In two rounds of testing, the FAs scores were achieved as follows: ChatGPT-3.5: 58% and 62%, ChatGPT-4: 63% and 77%, and BING AI: 81% and 73%. The incorporation of EA did not yield a significant enhancement in overall performance. The achieved gains for ChatGPT-3.5, ChatGPT-4, and BING AI were as a result 7% and 5%, 5% and 2%, and 3% and 1%, respectively (p>0.3). Within urological subtopics, LLMs showcased best performance in Pediatrics/Congenital and comparatively less effectiveness in Functional/BPS/Incontinence. CONCLUSION: LLMs exhibit suboptimal urology knowledge and unsatisfactory proficiency for educational purposes. The overall accuracy did not significantly improve when combining EA to FA. The error rates remained high ranging from 16 to 35%. Proficiency levels vary substantially across subtopics. Further development of medicine specific LLMs is required before integration into urological training programs.

How does artificial intelligence master urological board examinations? A comparative analysis of different Large Language Models' accuracy and reliability in the 2022 In-Service Assessment of the European Board of Urology.

PURPOSE: This study is a comparative analysis of three Large Language Models (LLMs) evaluating their rate of correct answers (RoCA) and the reliability of generated answers on a set of urological knowledge-based questions spanning different levels of complexity. METHODS: ChatGPT-3.5, ChatGPT-4, and Bing AI underwent two testing rounds, with a 48-h gap in between, using the 100 multiple-choice questions from the 2022 European Board of Urology (EBU) In-Service Assessment (ISA). For conflicting responses, an additional consensus round was conducted to establish conclusive answers. RoCA was compared across various question complexities. Ten weeks after the consensus round, a subsequent testing round was conducted to assess potential knowledge gain and improvement in RoCA, respectively. RESULTS: Over three testing rounds, ChatGPT-3.5 achieved RoCa scores of 58%, 62%, and 59%. In contrast, ChatGPT-4 achieved RoCA scores of 63%, 77%, and 77%, while Bing AI yielded scores of 81%, 73%, and 77%, respectively. Agreement rates between rounds 1 and 2 were 84% (κ = 0.67, p < 0.001) for ChatGPT-3.5, 74% (κ = 0.40, p < 0.001) for ChatGPT-4, and 76% (κ = 0.33, p < 0.001) for BING AI. In the consensus round, ChatGPT-4 and Bing AI significantly outperformed ChatGPT-3.5 (77% and 77% vs. 59%, both p = 0.010). All LLMs demonstrated decreasing RoCA scores with increasing question complexity (p < 0.001). In the fourth round, no significant improvement in RoCA was observed across all three LLMs. CONCLUSIONS: The performance of the tested LLMs in addressing urological specialist inquiries warrants further refinement. Moreover, the deficiency in response reliability contributes to existing challenges related to their current utility for educational purposes.

Predictors of Positive Surgical Margins after Robot-Assisted Partial Nephrectomy for Localized Renal Tumors: Insights from a Large Multicenter International Prospective Observational Project (The Surface-Intermediate-Base Margin Score Consortium).

Background: To explore predictors of positive surgical margins (PSM) after robotic partial nephrectomy (PN) in a large multicenter international observational project, harnessing the Surface-Intermediate-Base (SIB) margin score to report the resection technique after PN in a standardized way. Methods: Data from consecutive patients with cT1-2N0M0 renal masses treated with PN from September 2014 to March 2015 at 16 tertiary referral centers and included in the SIB margin score International Consortium were prospectively collected. For the present study, only patients treated with robotic PN were included. Uni- and multivariable analysis were fitted to explore clinical and surgical predictors of PSMs after PN. Results: Overall, 289 patients were enrolled. Median (IQR) preoperative tumor size was 3.0 (2.3−4.2) cm and median (IQR) PADUA score was 8 (7−9). SIB scores of 0−2 (enucleation), 3−4 (enucleoresection) and 5 (resection) were reported in 53.3%, 27.3% and 19.4% of cases, respectively. A PSM was recorded in 18 (6.2%) patients. PSM rate was 4.5%, 11.4% and 3.6% in case of enucleation, enucleoresection and resection, respectively. Patients with PSMs had tumors with a higher rate of contact with the urinary collecting system (55.6% vs. 27.3%; p < 0.001) and a longer median warm ischemia time (22 vs. 16 min; p = 0.02) compared with patients with negative surgical margins, while no differences emerged between the two groups in terms of other tumor features (i.e., pathological diameter, PADUA score). In multivariable analysis, only enucleoresection (SIB score 3−4) versus enucleation (SIB score 0−2) was found to be an independent predictor of PSM at final pathology (HR: 2.68; 95% CI: 1.25−7.63; p = 0.04), while resection (SIB score 5) was not. Conclusions: In our experience, enucleoresection led to a higher risk of PSMs as compared to enucleation. Further studies are needed to assess the differential impacts of resection technique and surgeon's experience on margin status after robotic PN.

Impact of Trifecta definition on rates and predictors of "successful" robotic partial nephrectomy for localized renal masses: results from the Surface-Intermediate-Base Margin Score International Consortium.

BACKGROUND: Over the years, five different Trifecta score definitions have been proposed to optimize the framing of "success" in partial nephrectomy (PN) field. However, such classifications rely on different metrics. The aim of the present study was to explore how the success rate of robotic PN, as well as its drivers, vary according to the currently available definitions of Trifecta. METHODS: Data from consecutive patients with cT1-2N0M0 renal masses treated with robotic PN at 16 referral centers from September 2014 to March 2015 were prospectively collected. Trifecta rate was defined for each of the currently available definitions. Multivariable logistic regression analysis was used to evaluate possible predictors of "Trifecta failure" according to the different adopted formulation. RESULTS: Overall, 289 patients met the inclusion criteria. Among the definitions, Trifecta rates ranged between 66.4% and 85.9%. Multivariable analysis showed that predictors for "Trifecta failure" were mainly tumor-related (i.e. tumor's nephrometry) for those Trifecta scores relying on WIT as a surrogate metric for postoperative renal function deterioration (definitions 1,2), while mainly surgery-related (i.e. ischemia time and excision strategy) for those including the percentage change in postoperative eGFR as the functional cornerstone of Trifecta (definitions 3-5). CONCLUSIONS: There was large variability in rates and predictors of "unsuccessful PN" when using different Trifecta scores. Further research is needed to improve the value of the Trifecta metrics, integrating them into routine patient counseling and standardized assessment of surgical quality across institutions.

Impact of surgical approach and resection technique on the risk of Trifecta Failure after partial nephrectomy for highly complex renal masses.

INTRODUCTION: We aimed to compare the outcomes of open vs robotic partial nephrectomy (PN), focusing on predictors of Trifecta failure in patients with highly complex renal masses. PATIENTS AND METHODS: We queried the prospectively collected database from the SIB International Consortium, including 507 consecutive patients with cT1-2N0M0 renal masses treated at 16 high-volume referral centres, to select those with highly complex (PADUA score ≥10) tumors undergoing PN. RT was classified as enucleation, enucleoresection or resection according to the SIB score. Trifecta was defined as achievement of negative surgical margins, no acute kidney injury and no Clavien-Dindo grade ≥2 postoperative surgical complications. Multivariable logistic regression analysis was used to assess independent predictors of Trifecta failure. RESULTS: 113 patients were included. Patients undergoing open PN (n = 47, 41.6%) and robotic PN (n = 66, 58.4%) were comparable in baseline characteristics. RT was classified as enucleation, enucleoresection and resection in 46.9%, 34.0% and 19.1% of open PN, and in 50.0%, 40.9% and 9.1% of robotic PN (p = 0.28). Trifecta was achieved in significantly more patients after robotic PN (69.7% vs. 42.6%, p = 0.004). On multivariable analysis, surgical approach (open vs robotic, OR: 2.62; 95%CI: 1.11-6.15, p = 0.027) and tumor complexity (OR for each additional unit of the PADUA score: 2.27; 95%CI: 1.27-4.06, p = 0.006) were significant predictors of Trifecta failure, while RT was not. The study is limited by lack of randomization; as such, selection bias and confounding cannot be entirely ruled out. CONCLUSIONS: Tumor complexity and surgical approach were independent predictors of Trifecta failure after PN for highly complex renal masses.

The long-term outcome of urethrotomy for primary urethral strictures: a population-based analysis.

OBJECTIVE: To determine the long-term outcome of endoscopic urethrotomy for primary urethral strictures based on a population-based approach. PATIENTS AND METHODS: We analysed a nationwide database of all patients with urethral stricture disease who underwent endoscopic urethrotomy as a primary intervention between January 2006 and December 2007. All patients were followed individually for 7-9 years. Frequencies and types of surgical re-interventions were documented. Repeat surgical interventions were stratified into three treatment types: urethrotomy, urethroplasty, and end-to-end urethral anastomosis. RESULTS: A total of 1203 men underwent urethrotomy during the index period. The median (SD, range) patient age was 63 (15.7, 20-85) years. A total of 136 patients (11%) died during follow-up. Within the follow-up period, 932 patients (78%) received no further surgical re-intervention for recurrent disease, and 176 patients (14.6%) required one, 53 (4.5%) two, and 41 (3.4%) three or more procedures. The mean number of re-interventions was 1.5/patient and the lowest re-intervention rate was in patients aged ≥80 years (13.9%). In 236 cases (68%) at least one repeat urethrotomy was performed. An open reconstruction was performed in 87 cases (32%), with urethroplasty in 21 patients (24%), and end-to-end anastomosis in 66 patients (76%). The mean interval until re-intervention was 29.5 months. CONCLUSIONS: This long-term population-based study suggests that the invasive re-treatment rate in men following initial urethrotomy is 22% within 8 years and lowest in the advanced age cohort.

Impact of Resection Technique on Perioperative Outcomes and Surgical Margins after Partial Nephrectomy for Localized Renal Masses: A Prospective Multicenter Study.

PURPOSE: The impact of resection technique on partial nephrectomy outcomes is controversial. The aim of this study was to evaluate the pattern of resection techniques during partial nephrectomy and the impact on perioperative outcomes, acute kidney injury, positive surgical margins and the achievement of the Trifecta (negative surgical margins, no perioperative Clavien-Dindo grade 2 or greater surgical complications and no postoperative acute kidney injury). MATERIALS AND METHODS: We prospectively collected data on consecutive patients with cT1-2N0M0 renal masses treated with partial nephrectomy at a total of 16 referral centers from September 2014 to March 2015. After partial nephrectomy the resection technique was classified by the surgeon as enucleation, enucleoresection or resection according to the SIB (Surface-Intermediate-Base) margin scores 0 to 2, 3 or 4 and 5, respectively. Multivariable logistic regression analysis was done to evaluate the potential impact of the resection technique on postoperative surgical complications, positive surgical margins, acute kidney injury and Trifecta achievement. RESULTS: Overall 507 patients were included in analysis. The resection technique was classified as enucleation in 266 patients (52%), enucleoresection in 150 (30%) and resection in 91 (18%). The resection technique (enucleoresection vs enucleation and resection) was the only significant predictor of positive surgical margins. Tumor complexity, surgical approach (open and laparoscopic vs robotic) and resection technique (enucleoresection vs enucleation) were significant predictors of Clavien-Dindo grade 2 or greater surgical complications. The surgical approach (open and laparoscopic vs robotic), the resection technique (enucleoresection vs enucleation) and warm ischemia time were significantly associated with postoperative acute kidney injury and Trifecta achievement. CONCLUSIONS: Resection techniques significantly impact surgical complications, early functional outcomes and positive surgical margins after partial nephrectomy of localized renal masses.

Real-World Evidence Data on Metastatic Renal-Cell Carcinoma Treatment in Austria: The RELACS Study.

BACKGROUND: Treatment decisions in routine clinical practice are based on reports of clinical trials, which represent highly selected populations. Limited studies reported real-world evidences representing routine clinical practices in patients with renal-cell carcinoma (RCC) in Europe. The aim of this retrospective, noninterventional chart review was to collect data on the treatment landscape for patients with advanced/metastatic RCC in routine clinical practice in a broader patient population in Austria. PATIENTS AND METHODS: Patients with advanced/metastatic RCC receiving systemic treatment between June 2010 and June 2016 across 12 centers in Austria were included. Parameters were entered into an electronic case report form from the participating sites via the application Hermesoft electronic data capture system. Progression-free survival (PFS) and overall survival (OS) were the 2 primary end points. RESULTS: The median PFS and OS were 12 months and 44 months, respectively (first-line PFS was 14 months for pazopanib and 13 months for sunitinib; first-line OS was 44 months for pazopanib and 48 months for sunitinib). Factors influencing the OS were sex, with female patients at a significantly higher risk than male patients (hazard ratio = 1.719), Eastern Cooperative Oncology Group performance status > 0 increased the risk twice (hazard ratio = 2.048), and number of metastases > 3 before the first line doubled the risk compared to metastases (hazard ratio = 2.064). CONCLUSION: OS in this retrospective chart review was considerably longer than the previous reports in real-world patients, underlining the benefit of current RCC treatment options in routine clinical practice.

Impact of Metabolic Diseases, Drugs, and Dietary Factors on Prostate Cancer Risk, Recurrence, and Survival: A Systematic Review by the European Association of Urology Section of Oncological Urology.

CONTEXT: To date, established risk factors for prostate cancer (PCa) are limited to age, race, family history, and certain genetic polymorphisms. Despite great research efforts, available evidence on potentially modifiable risk factors is conflicting. Moreover, most studies on PCa risk factors did not consider the impact of prostate-specific antigen (PSA) testing on PCa diagnosis. OBJECTIVE: To provide a detailed overview of the latest evidence on the role of metabolic diseases, drugs, and dietary factors for risk of PCa incidence, recurrence, and survival in men exposed to PSA testing. EVIDENCE ACQUISITION: A systematic review of the English-language literature was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Randomized, case-control, or cohort studies published during the periods 2008-2017 (on drugs and metabolic diseases) and 2003-2017 (on dietary factors), with extensive follow-up (≥8-10yr for studies on PCa risk; ≥2-5yr for studies on PCa recurrence, progression, and survival, depending on the review subtopic) and adjusting of the analyses, beyond established risk factors, for either rate of PSA testing (for risk analyses) or PCa stage and primary treatment (for survival analyses), were eligible for inclusion. EVIDENCE SYNTHESIS: Overall, 39 reports from 22 observational studies were included. Studies were heterogeneous regarding definitions of exposure or outcomes, length of follow-up, risk of bias, and confounding. For some risk factors, evidence was insufficient to assess potential effects, while for others there was no evidence of an effect. For selected risk factors, namely metformin, aspirin and statin use, diabetes, obesity, and specific dietary intakes, there was low-quality evidence of modest effects on PCa risk. CONCLUSIONS: Current evidence from long-term observational studies evaluating the effect of drugs, metabolic diseases, and dietary factors for PCa risk considering the impact of PSA testing is still not conclusive. Future research is needed to confirm the associations suggested by our review, exploring their potential biological explanations and selecting those risk factors most likely to trigger effective public health interventions. PATIENT SUMMARY: We reviewed the available studies published in the recent literature on the potential role of drugs, metabolic diseases, and food and dietary factors for the risk of prostate cancer, considering the impact of prostate-specific antigen testing on prostate cancer diagnosis. We found that for some factors data are currently insufficient to make definitive conclusions, while for others available studies seem to indicate an effect on the risk of prostate cancer.

Latest Evidence on the Impact of Smoking, Sports, and Sexual Activity as Modifiable Lifestyle Risk Factors for Prostate Cancer Incidence, Recurrence, and Progression: A Systematic Review of the Literature by the European Association of Urology Section of Oncological Urology (ESOU).

CONTEXT: Smoking, sexual activity, and physical activity (PA) are discussed as modifiable lifestyle factors associated with prostate cancer (PCa) development and progression. OBJECTIVE: To evaluate the available evidence concerning the association of smoking, sexual activity, and sports and exercise on PCa risk, treatment outcome, progression, and cancer-specific mortality. EVIDENCE ACQUISITION: A systematic review of studies published between 2007 and 2017 using MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement criteria was conducted. EVIDENCE SYNTHESIS: While data concerning the impact of smoking on PCa development remain conflicting, there is robust evidence that smoking is associated with aggressive tumor features and worse cancer-related outcome, which seems to be maintained for 10 yr after smoking cessation. Less convincing and limited evidence exists for the association of sexual activity with PCa risk. The findings related to PA and PCa support the inference that exercise might be a useful factor in the prevention of PCa and tumor progression, while it is not finally proved under which specific conditions PA might be protective against disease development. CONCLUSIONS: Smoking is associated with aggressive tumor features and worse cancer-related prognosis; as this negative impact seems to be maintained for 10yr after smoking cessation, urologists should advise men to quit smoking latest at PCa diagnosis to improve their prognosis. As several studies indicate a positive impact of exercise on tumor development, progression, and treatment outcome, it is certainly reasonable to advocate an active lifestyle. Least convincing evidence is available for the interaction of sexual activity and PCa, and well-conducted and longitudinal studies are clearly necessary to evaluate whether the suggested associations between PCa risk and sexual behavior are real or spurious. PATIENT SUMMARY: In this systematic review, we looked at the impact of smoking, sexual activity, and sports and exercise on prostate cancer risk and outcome after treatment. While the evidence for sexual activity is not overall clear, we found that smoking might lead to more aggressive cancers and result in worse treatment outcome. Physical activity might prevent prostate cancer and improve cancer-related outcomes as well. Hence, it is certainly reasonable to advocate an active lifestyle and advise men to quit smoking.

Assessment of volume preservation performed before or after partial nephrectomy accurately predicts postoperative renal function: Results from a prospective multicenter study.

PURPOSE: Partial nephrectomy (PN) is standard for small renal masses, improving renal function by preserving renal parenchyma compared with radical nephrectomy. Recent work demonstrated that postoperative surgeon assessment of volume preservation (SAVP) and 3D imaging measurements agree and correlate with postoperative function. We hypothesize preoperative assessment of volume preservation (PAVP) with PN based on preoperative imaging will reliably indicate postoperative renal function. MATERIALS AND METHODS: Data were collected from 336 patients undergoing PN for suspected renal cancer by 40 surgeons at 12 centers in Europe and the United States within the Surface-Intermediate-Base International Consortium. Surgeons recorded PAVP and SAVP for individual patients; pre- and postoperative glomerular filtration rate (GFR) was estimated by Chronic Kidney Disease Epidemiology Collaboration equations. Correlations between PAVP, SAVP, and postoperative GFR were assessed with linear regression models. Bland-Altman analysis was used to assess agreement between PAVP and SAVP with a significant cutoff of 5%. RESULTS: Median PAVP was 90% (interquartile range [IQR] 85%-100%) and SAVP was 90% (IQR: 80%-94%). PAVP and SAVP were moderately correlated (R2 = 0.67, P < 0.0001) and deemed "interchangeable" by Bland-Altman analysis at a 5% acceptable rate of difference (95% CI: -5.4, -3.1). Median postoperative GFR was 77.3 (IQR: 56.2, 92.0). Both PAVP (R2 = 0.82, P < 0.0001) and SAVP (R2 = 0.83, P < 0.0001) were correlated with postoperative GFR. Multivariable models utilizing volume-adjusted GFR based on PAVP or SAVP significantly and similarly predicted postoperative GFR (R2 = 0.72 for each). CONCLUSION: Renal function is closely linked to the amount of parenchymal volume preservation, whether estimated prior to surgery (PAVP) or afterward (SAVP). PAVP provides reasonably accurate information for decision-making in patients considering PN.

Does the Unexpected Presence of Non-organ-confined Disease at Final Pathology Undermine Cancer Control in Patients with Clinical T1N0M0 Renal Cell Carcinoma Who Underwent Partial Nephrectomy?

BACKGROUND: A non-negligible proportion of individuals diagnosed with cT1 renal cell carcinoma (RCC) are upstaged to pT3a at final pathology. Few data on oncological outcomes for these patients are available to determine whether partial nephrectomy (PN) might jeopardise cancer control. OBJECTIVE: To assess, within an international multi-institutional collaboration, whether PN might undermine cancer control relative to radical nephrectomy (RN) in RCC patients with unexpected pT3a disease. DESIGN, SETTING, AND PARTICIPANTS: International multi-institutional collaboration including patients with cT1abN0M0-pT3a RCC. INTERVENTION: PN or RN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We used Kaplan-Meier analyses, before and after propensity-score matching, to evaluate differences in metastatic progression (MP) and cancer-specific mortality (CSM) rates during follow-up. Univariable and multivariable Cox regression analyses were used to assess predictors of MP and CSM. RESULTS AND LIMITATIONS: Overall, 309 patients with cT1abN0M0 RCC (cT1aN0M0, n=107, 34.6%; cT1bN0M0, n=202, 65.4%) had pT3a disease according to final pathology. Patients were treated with either PN (n=71, 23%) or RN (n=238, 77%). MP at 1, 2, and 5 yr was detected in 9.1%, 13.3%, and 24.1% of patients, respectively. CSM was 3.5%, 10.7%, and 18.4% at 1, 2, and 5 yr, respectively. After matching, no difference in terms of MP or CSM was observed between the PN and RN cohorts (both p>0.3). On multivariable analysis, type of surgery (PN vs RN) was not an independent predictor of either MP (p=0.3) or CSM (p=0.4). Limitations include the retrospective design. CONCLUSIONS: In patients with unexpected pT3a RCC at final pathology, PN does not appear to jeopardise cancer control with regard to MP and CSM. PATIENT SUMMARY: Cancer control is similar between patients treated with removal of the entire kidney and those with only partial removal, even if the final histology examination demonstrates a tumour that is unexpectedly not confined within the kidney.

Current Status of Focal Cryoablation for Small Renal Masses.

Focal cryoablation is an established minimally invasive technique for the treatment of small renal masses. Because of the lack of robust evidence, it is indicated in selected patients who have relative contraindications to extirpative approaches. With appropriate selection of patients, cryoablation is safe and effective. Main advantages are low risk for complication, minimal invasiveness, and good functional outcomes; oncological outcomes require further studies. The role of the percutaneous approach has been expanding because of its ability to reduce pain and hospitalization, the possibility of performing the procedure under sedation, and the fact that it is potentially more cost effective.

Periarterial papaverine improves early postoperative renal function after retroperitoneoscopic partial nephrectomy.

OBJECTIVE: To study the impact of periarterial papaverine application on the postoperative glomerular filtration rate (GFR) after retroperitoneoscopic partial nephrectomy (PN). MATERIALS AND METHODS: A consecutive series of patients underwent retroperitoneoscopic PN with intraoperative, periarterial application of 50 mg of papaverine. These patients were compared with a group of patients who underwent retroperitoneoscopic PN at this institution prior to this protocol. Patients were matched for preoperative GFR, tumor size, ischemia time, and operative time. RESULTS: In total, 37 patients who received periarterial papaverine (P) and 37 patients without periarterial papaverine, who served as controls (C), were included in this analysis and matched according to preoperative GFR (P: 98.2, C: 97.8 ml/min/1.72 m(2)), tumor size (P: 2.5 cm, C: 2.5 cm), ischemia time (P: 22 min, C: 23 min), and operative time (P: 86 min, C: 85 min). Postoperative GFR was 86.4 ml/min/1.72 m(2) in controls (C) and 91.8 ml/min/1.72 m(2) in the papaverine group. The pre- to postoperative decrease in GFR was reduced by 56.9% in the papaverine group compared with controls (relative decrease in GFR: P: 5.3% vs. C: 12.5%; P = 0.02). Intra- and postoperative complications were pneumothorax (P: n = 2, C: n = 3), urinary fistula (P: n = 0, C: n = 2), and one suture-fixed drainage (P: n = 1, C: n = 0). No papaverine-related side effects were observed, and the surgical procedure was not hampered by the periarterial application of papaverine. CONCLUSION: As with laparoscopic donor nephrectomy, periarterial papaverine seems to improve postoperative renal function after retroperitoneoscopic partial nephrectomy. This nephroprotective effect might be particularly advantageous for patients with an impaired renal function preoperatively.

Positive surgical margins after nephron-sparing surgery.

CONTEXT: Little is known on the natural history of positive surgical margins (PSMs) in partial nephrectomy (PN). Accumulating data suggest that secondary nephrectomy might not be necessary in all patients with PSMs after PN. OBJECTIVE: Provide an overview on incidence and risk factors for PSMs after partial nephrectomy and on the rate of local and distant disease recurrence related to PSMs. We also provide recommendations on how to avoid and how to treat PSMs after PN. EVIDENCE ACQUISITION: A nonsystematic literature research was based on Medline, Scopus, and Web of Science queries on these keywords: nephron-sparing surgery, partial nephrectomy/ies, and margin. Only human studies (original research) published in English were included. EVIDENCE SYNTHESIS: PSMs are present in 0-7% of patients after open PN, in 0.7-4% after laparoscopic PN, and in 3.9-5.7% after robot-assisted PN. The thickness of healthy parenchyma surrounding the tumour is irrelevant as long as complete tumour removal is achieved. The coincidence of a highly malignant tumour and PSM increases the risk of local recurrence. Intermediate follow-up data indicate that the vast majority of patients with PSMs will not experience local or distant tumour recurrence. Frozen-section analysis for evaluation of resection margins during PN is of minor clinical significance, as the surgeon's gross assessment of macroscopically negative margins provides reliable results. CONCLUSIONS: PSMs in PN are rare. As indicated by intermediate follow-up data, the majority of patients with PSMs after PN remain without disease recurrence, and a surveillance strategy seems preferable to surgical reintervention.