Incidence and management of BPH surgery-related urethral stricture: results from a large U.S. database.

INTRODUCTION AND OBJECTIVES: Urethral stricture (US) is a well-known complication after surgical treatment of benign prostatic hyperplasia (BPH). This study aimed to evaluate the contemporary incidence of the US after different types of BPH surgery, to identify associated risk factors and to assess its management. METHODS: A retrospective analysis was conducted using the PearlDiver™ Mariner database, containing de-identified patient records compiled between 2011 and 2022. Specific International Classification of Diseases (ICD) and Current Procedural Terminology (CPT) codes were employed to identify population characteristics and outcomes. All the most employed surgical procedures for BPH treatment were considered. Multivariable logistic regression was employed to evaluate factors associated with diagnosis of post-operative US. RESULTS: Among 274,808 patients who underwent BPH surgery, 10,918 developed post-operative US (3.97%) within 12 months. Higher incidence of US was observed following TURP (4.48%), Transurethral Incision of the Prostate (TUIP) (3.67%), Photoselective Vaporization of the Prostate (PVP) (3.92%), HoLEP/ThuLEP (3.85%), and open Simple Prostatectomy (SP) (3.21%). Lower incidence rates were observed after laparoscopic\robot-assisted SP (1.76%), Aquablation (1.59%), Prostatic Urethral Lift (PUL) (1.07%), Rezum (1.05%), and Prostatic Artery Embolization (PAE) (0.65%). Multivariable analysis showed that patients undergoing PUL, Rezum, Aquablation, PAE, and PVP were associated with a reduced likelihood of developing US compared to TURP. US required surgical treatment in 18.95% of patients, with direct visual internal urethrotomy (DVIU) and urethroplasty performed in 14.55% and 4.50% of cases, respectively. Urethral dilatation (UD) in an outpatient setting was the primary management in most cases (76.7%). CONCLUSIONS: The present analysis from a contemporary large dataset suggests that the incidence of US after BPH surgery is relatively low (<5%) and varies among procedures. Around 94% of US cases following BPH surgery are managed using minimally invasive treatment approaches such as UD and DVIU.

Benign Prostatic Hyperplasia Surgery: A Snapshot of Trends, Costs, and Surgical Retreatment Rates in the USA.

BACKGROUND: An increasing number of novel surgical treatments (NSTs) for benign prostatic hyperplasia (BPH) have been proposed over time to achieve similar functional outcomes, but better perioperative and sexual outcomes than traditional procedures. OBJECTIVE: To assess the trends in the utilization and costs of BPH surgical procedures over the past decade, and to analyze the need for surgical retreatment after each procedure. DESIGN, SETTING, AND PARTICIPANTS: A retrospective observational population-based analysis was conducted using the PearlDiver Mariner (PearlDiver Technologies, Colorado Springs, CO, USA) database, including all-payer nationally available claims records collected from 2011 to 2022. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The number and type of BPH surgical procedures per year, costs associated with each BPH surgical treatment, incidence of BPH surgical retreatment rate, and time to BPH surgical retreatment were assessed. Negative binomial regression and Cochran-Armitage test were used for the temporal trend analysis. A multivariable logistic regression analysis evaluated the predictors of BPH surgical retreatment. RESULTS AND LIMITATIONS: In the study period, 274 808 patients received surgical treatment for BPH. The most common procedure was transurethral resection of the prostate (TURP; 71.7%). The overall utilization of BPH surgical treatment increased over the study period. Traditional surgery remained most performed for the entire period (87.8%), but a statistically significantly rising trend of NSTs was recorded. The mean reimbursements paid per procedure was 1.43 times higher (p < 0.001) for NSTs than for traditional procedures. The surgical retreatment rate was 9.4%. The mean time to surgical retreatment was 25.3 mo, with 85.5% of cases re-treated within 5 yr. At the multivariable analysis, transurethral incision of the prostate, photoselective vaporization of the prostate, prostatic urethral lift, convective water vapor energy, and prostatic artery embolization had a significantly greater likelihood of surgical retreatment than TURP. Holmium/thulium laser enucleation of the prostate (HoLEP/ThuLEP), open simple prostatectomy (SP), and laparoscopic/robot-assisted SP were associated with a lower probability of resurgery than TURP, but a similar probability between these procedures. Retrospective design and a lack of relevant clinical data were the main limitations. CONCLUSIONS: Over the past decade, there has been a progressive increase in the adoption of NSTs. The rate of surgical retreatment appears <10%, with patients undergoing SP and HoLEP/ThuLEP experiencing a statistically significantly lower probability of surgical retreatment. PATIENT SUMMARY: We investigated the trends, costs, and surgical retreatments of benign prostatic hyperplasia surgery. Transurethral resection of the prostate remains the most common procedure. Novel surgical treatments are associated with an upward trend, despite appearing more expensive overall. Retreatment is necessary in <10% of patients and generally within 5 yr.

Trends and Costs of Minimally Invasive Surgery for Kidney Cancer in the US: A Population-based Study.

OBJECTIVE: To analyze temporal trends and costs associated with the use of minimally invasive surgery (MIS) for kidney cancer in the US over the past decade. To examine the impact of social determinants of health (SDOH) on perioperative outcomes. METHODS: The PearlDiver Mariner, a national database of insurance billing records, was queried for this retrospective observational cohort analysis. The MIS population was identified and stratified according to treatment modality, using International Classification of Diseases and current procedural terminology codes. SDOH were assessed using International Classification of Diseases codes. Negative binomial regression was used to evaluate the overall number of renal MIS and Cochran-Armitage tests to compare the utilization of different treatment modalities, over the study period. Multivariable logistic regression analysis identified predictors of perioperative complications. RESULTS: A total of 80,821 MIS for kidney cancer were included. Minimally invasive partial nephrectomy adoption as a fraction of total MIS increased significantly (slope of regression line, reg. = 0.026, P <.001). Minimally invasive radical nephrectomy ($26.9k ± 40.9k) and renal ablation ($18.9k ± 31.6k) were the most expensive and cheapest procedures, respectively. No statistically significant difference was observed in terms of number of complications (P = .06) and presence of SDOH (P = .07) among the treatment groups. At multivariable analysis, patients with SDOH undergoing minimally invasive radical nephrectomy had higher odds of perioperative complications, while renal ablation had a significantly lower probability of perioperative complications. CONCLUSION: This study describes the current management of kidney cancer in the US, offering a socioeconomic perspective on the impact of this disease in everyday clinical practice.

Single port robot-assisted pyeloplasty: An early comparative outcomes analysis.

BACKGROUND: The treatment paradigm for ureteropelvic junction obstruction (UPJO) has shifted towards minimally invasive pyeloplasty. A comparison Single Port (SP) and Multi Port (MP) robot-assisted pyeloplasty (RAP) was performed. METHODS: Data from consecutive patients undergoing SP RAP or MP RAP between January 2021 and September 2023 were collected and analysed. Co-primary outcomes were length of stay (LOS), Defense and Veterans Pain Rating Scale (DVPRS), and narcotic dose. The choice of the robotic system depended on the surgeon's preference and availability of a specific robotic platform. RESULTS: A total of 10 SP RAPs and 12 MP RAPs were identified. SP RAP patients were significantly younger [23 years (20-34)] than MP RAP [42 years (35.5-47.5), p < 0.01]. No difference in terms of OT (p = 0.6), LOS (p = 0.1), DVPRS (p = 0.2) and narcotic dose (p = 0.1) between the two groups was observed. CONCLUSIONS: SP RAP can be implemented without compromising surgical outcomes and potentially offering some clinical advantages.

Single-port vs multi-port robot-assisted partial nephrectomy: A single center propensity score-matched analysis.

INTRODUCTION AND OBJECTIVES: The aim of the study is to compare key outcomes of Single-Port (SP) and Multi-Port (MP) robot-assisted partial nephrectomy (RAPN). METHODS: A retrospective analysis was conducted on our prospectively collected database of patients who underwent SP-RAPN or MP-RAPN at our institution from January 2021 to August 2023. To adjust for potential baseline pre-operative confounders, a 1:1 propensity-score matching analysis (PSMa) was performed. The primary endpoint was to compare perioperative outcomes between the two groups. The secondary endpoint was to compare the achievement of the "Trifecta" outcome (defined as negative surgical margins, absence of high-grade complications and change in eGFR values (ΔeGFR) < 10% at 6 months follow-up) in the matched cohort. RESULTS: After PSMa, 30 SP cases were matched 1:1 to 30 MP cases. In the matched cohort, there were no significant differences between SP and MP approaches in operative time, estimated blood loss, ischemia time, transfusions rate, intraoperative complications, postoperative complications, and positive surgical margin rates. Patients who underwent SP-RAPN had a shorter median length of stay [25 (IQR:24.0-34.5) vs 34 (IQR:30.2-48.0) hours, p < 0.003]. The Trifecta outcome was achieved in 16 (57%) of SP patients and 17 (63%) of MP patients (p = 0.8). CONCLUSIONS: SP-RAPN can be safely implemented in a Center with an established MP-RAPN program. Despite being early in the SP-RAPN experience, key surgical outcomes are not compromised. While offering comparable perioperative and short-term functional outcomes, SP-RAPN can translate into faster recovery and shorter LOS, paving the way for outpatient robotic surgery.

Toll-Like Receptor 4 Induction During Renal Ischemia Correlates with Serum Creatinine in a Pig Model.

Objectives: To determine whether toll-like receptor 4 (TLR4), a mediator of organ ischemia-reperfusion injury, is overexpressed during warm ischemia in a porcine solitary kidney model, and whether its expression correlates with creatinine, a surrogate for kidney function. Materials and Methods: Eight adult Yorkshire pigs underwent initial laparoscopic nephrectomy. After 1 week, animals were randomized into two groups: group 1 underwent laparoscopic renal hilar dissection, renal ischemia by cross-clamping, and reperfusion (ischemia group); group 2 underwent laparoscopic renal hilar dissection alone (sham group). Animals were survived to day 7 postrandomization. Peripheral blood was sampled for serum creatinine (sCr) and TLR4 expression at the following time points or corresponding intervals: prenephrectomy, 1-week postnephrectomy (preischemia), after 90 minutes of ischemia, 30 minutes postreperfusion, and at sacrifice. Intragroup TLR4 expression changes were analyzed using repeated measures ANOVA. Intergroup TLR4 expression was compared using Mann-Whitney's test. Correlation between sCr and TLR4 was assessed using Spearman's test. Results: Seven animals completed the experiment (four ischemia and three sham). Relative TLR4 expression significantly increased from baseline levels during ischemia, reperfusion, and sacrifice time points only in the ischemia group, and was significantly higher for the ischemia group after 90 minutes of ischemia (p = 0.034). sCr was significantly higher for the ischemia group during the reperfusion phase (p = 0.048). Relative TLR4 expression level significantly correlated with sCr in the overall cohort (Spearman's rho = 0.69) and in the ischemia group (Spearman's rho = 0.82; p < 0.0001 for each). Conclusions: Warm ischemia in a porcine solitary kidney induces acute overexpression of TLR4 in peripheral blood leukocytes, which is detectable. Relative TLR4 expression level strongly correlated with sCr but had an observable change sooner than change in sCr. Pending further investigation, TLR4 overexpression during renal ischemia may represent a sensitive quantitative marker of unilateral renal injury sustained during nephron-sparing surgery.

Association Between Mental Health Conditions and Postoperative Complications After Gender-Affirming Surgery.

This cohort study assesses whether postoperative complications are associated with having been diagnosed with a mental health condition in patients who have undergone gender-affirming surgery.

Prolieve Transurethral Thermodilatation for Treatment of Symptomatic Benign Prostatic Hyperplasia: 5-Year Results from a Prospective Multicenter Trial.

Introduction and Objective: Prolieve® transurethral thermodilatation (TUTD) is the only third-generation transurethral microwave thermotherapy (TUMT) device that incorporates balloon dilation/compression of the prostatic urethra with cooled TUMT, at ≤50 W power. We evaluated its 5-year efficacy in the treatment of symptomatic benign prostatic hyperplasia (BPH) in an open-label prospective multicenter trial. Methods: Eligible patients with American Urological Association symptom index score (AUASS) ≥9, peak urine flow rate (Qmax) <12 mL/s, and prostate size 20-80 g without obstructing median lobe were enrolled. Prolieve TUTD was delivered in the office setting under local anesthesia. AUASS, quality of life (QOL), BPH impact index (BPHII), Qmax, and other measures were assessed at baseline, and at least annually thereafter to year 5. Adverse events (AEs) were recorded. Treatment success over time was analyzed using the Kaplan-Meier method while changes from baseline were evaluated using paired t-tests. Results: Intention to treat population was 225, of whom 220 with a mean (standard deviation) age of 65 (5.9) completed treatment. 187/220 (85%) did not require urethral catheterization. AUAS, QOL, and BPHII scores significantly improved from baseline in ≤3 months, with sustained improvements to year 5. Qmax also significantly improved from baseline at each annual follow-up evaluation. Cumulative 5-year surgical retreatment rate was 14.2% (95% confidence interval 9.5-20.8). Transient urinary urgency and dysuria were the most reported AEs. Conclusions: Prolieve TUTD is a safe and effective treatment option for BPH, with durable long-term improvements in voiding symptoms and urinary flow rates. It has a low catheterization rate and sexual side effects are rare. Clinical Trials.gov Registration Number: NCT02021032.

Pediatric hospitalizations for upper urinary tract calculi: Epidemiological and treatment trends in the United States, 2001-2014.

INTRODUCTION: The incidence of urolithiasis in the pediatric population in the United States has steadily been increasing over the past few decades. Few studies to date have examined trends in the hospitalization and inpatient surgical treatment of urolithiasis in the pediatric population using nationally representative data. OBJECTIVE: The aim was to evaluate nationwide trends in the rates of pediatric hospitalization and inpatient surgical activity for upper urinary tract calculi (UUTC) in the United States from 2001 to 2014. PATIENTS AND METHODS: The National Inpatient Sample (NIS) databases for 2001-2014 were queried. Hospitalizations for patients younger than age 18 (excluding newborns), with principal discharge diagnoses of kidney or ureteral calculi were selected. Surgical procedures during hospitalization were identified. Hospitalization and surgical activity data were analyzed using trends tests, chi-square statistics, and multivariable logistic regression as appropriate. RESULTS: Of an estimated 30.2 million pediatric hospitalizations during the study period, 44,369 overall (147 per 100,000) were for UUTC. The total number and proportion of UUTC hospitalizations per 100,000 all-cause admissions significantly decreased between 2001 and 2014 (p < 0.0001) (figure). Surgical intervention was undertaken in 19,946 (45%) of UUTC hospitalizations, with significantly increasing frequency over the study interval (p < 0.0001). Urinary tract drainage was the most frequently performed surgical intervention. On multivariable analysis, significant predictors of a higher likelihood of undergoing inpatient surgical intervention during hospitalization for UUTC included older age, female gender, deficiency anemias, hypertension, neurologic disorders, paralysis, and hospitalization after 2001. DISCUSSION: The declining trend in hospitalization for UUTC likely reflects a shift toward outpatient care for routine cases, reserving hospitalization for sicker patients or those with complications of urolithiasis. Similar to previous studies, we also observed that girls were significantly more likely than boys to be hospitalized for stone disease, and that majority of the stone activity in the pediatric population was in children aged 15-17 years. We also observed a sharp increase in the proportion of hospitalized patients who underwent surgical intervention between 2001 and 2014, but the primary driver of this trend remains uncertain. CONCLUSION: Pediatric hospitalizations for UUTC in US children significantly decreased between 2001 and 2014, while of those hospitalized the proportion who underwent stone-related surgical intervention significantly increased over the same period. A shift towards outpatient care, reserving hospitalization and inpatient surgical care for sicker patients, those with urolithiasis-related complications, or those who fail conservative management, is a possible explanation for these observed trends.

Use of Fluoroscopy and Potential Long-Term Radiation Effects on Cataract Formation.

INTRODUCTION: The lens of the eye is extremely susceptible to radiation and long-term exposure can induce cataract formation. Our objective was to explore the risk of cataract formation for urologists at our institution. METHODS: A retrospective review of a multisurgeon database of fluoroscopic cases between October 2013 to December 2014 was queried. Procedures were performed by different subspecialties and ranged from stent insertion/ureteroscopy to percutaneous nephrolithotomy. Fluoroscopic parameters were recorded from all cases and the radiation dosimetry was calculated through methods described by the National Council on Radiation Protection. The data were extrapolated to determine the risk of cataract formation. The technical specifications of the GE OEC 990 mobile C-arm unit were used for calculations. RESULTS: A total of 780 cases were analyzed, of which 182 were endourology cases. Average fluoroscopic time was 34.86 seconds per case. Average tube potential and current were 86.84 kV and 1.95 mA, respectively. Pediatric urologists utilized fluoroscopy the least, 11.84 seconds per case (p = 0.0022). Endourology trained faculty had fluoroscopy exposure of 68.35 seconds per case (p < 0.0001), whereas others were exposed 26.24 seconds per case (p < 0.0001). For the highest exposed urologist, the estimated dose to the eyes was 5.64 µGy per case. Total estimated cumulative dose over the study timeframe was 997.58 µGy, or 748.19 µGy per year. CONCLUSIONS: The defined threshold in the absorbed dose for cataract formation is 0.5 Gy. Resident exposure was the highest, at 11% of the annual limit, and the most exposed urologists had an estimated dose of 5% of the annual limit. At current exposure levels, it would not be feasible to reach the stated safety limit during 50 to 60 years of practice. However, changing exposure guidelines could result in stricter safety limits.

Comparison of Urinary Tract Infection Rates Associated with Transurethral Catheterization, Suprapubic Tube and Clean Intermittent Catheterization in the Postoperative Setting: A Network Meta-Analysis.

PURPOSE: We performed a network meta-analysis of available randomized, controlled trials to elucidate the risks of urinary tract infection associated with transurethral catheterization, suprapubic tubes and intermittent catheterization in the postoperative setting. MATERIALS AND METHODS: PubMed®, EMBASE® and Google Scholar™ searches were performed for eligible randomized, controlled trials from January 1980 to July 2015 that included patients who underwent transurethral catheterization, suprapubic tube placement or intermittent catheterization at the time of surgery and catheterization lasting up to postoperative day 30. The primary outcome of comparison was the urinary tract infection rate via a network meta-analysis with random effects model using the netmeta package in R 3.2 (www.r-project.org/). RESULTS: Included in analysis were 14 randomized, controlled trials in a total of 1,391 patients. Intermittent catheterization and suprapubic tubes showed no evidence of decreased urinary tract infection rates compared to transurethral catheterization. Suprapubic tubes and intermittent catheterization had comparable urinary tract infection rates (OR 0.903, 95% CI 0.479-2.555). On subgroup analysis of 10 randomized, controlled trials with available mean catheterization duration data in a total of 928 patients intermittent catheterization and suprapubic tube were associated with significantly decreased risk of urinary tract infection compared to transurethral catheterization when catheterization duration was greater than 5 days (OR 0.173, 95% CI 0.073-0.412 and OR 0.142, 95% CI 0.073-0.276, respectively). CONCLUSIONS: Transurethral catheterization is not associated with an increased urinary tract infection risk compared to suprapubic tubes and intermittent catheterization if catheterization duration is 5 days or less. However, a suprapubic tube or intermittent catheterization is associated with a lower rate of urinary tract infection if longer term catheterization is expected in the postoperative period.

Oncologic Efficacy of Radio Frequency Ablation for Small Renal Masses: Clear Cell vs Papillary Subtype.

PURPOSE: Current radio frequency ablation series do not distinguish renal cell carcinoma subtypes when reporting oncologic efficacy. Papillary neoplasms may be more amenable to radio frequency ablation than clear cell carcinoma because they are less vascular, which may limit heat energy loss. We report the long-term outcomes of patients treated with radio frequency ablation for small renal masses by renal cell carcinoma subtype. MATERIALS AND METHODS: The records of patients undergoing radio frequency ablation for small renal masses (cT1a) at 2 institutions from March 2007 to July 2012 were retrospectively reviewed. Patients were included in analysis if they had biopsy confirmed clear cell or papillary renal cell carcinoma histology. Patients had at least 1 contrast enhanced cross-sectional image following radio frequency ablation. Demographic data between tumor subtypes were compared using the paired t-test. Oncologic outcomes were determined by Kaplan-Meier survival analysis and survivor curves were compared with the log rank test. RESULTS: A total of 229 patients met study inclusion criteria. There were 181 clear cell tumors and 48 papillary tumors. Median followup was 33.2 months. There was no difference between tumor groups based on patient age, tumor size or grade, or months of followup. Five-year disease-free survival was 89.7% for clear cell tumors and 100% for papillary tumors (p = 0.041). There was no significant difference in overall survival (88.4% vs 89.6%, p = 0.764). CONCLUSIONS: Radio frequency ablation outcomes seem to be determined in part by renal cell carcinoma subtype with clear cell renal tumors having less favorable outcomes. We hypothesize that this is due to differences in tumor vascularity. Our experience suggests that future tumor ablation studies should consider reporting outcomes based on tumor cell types.

The performance of a modified RENAL nephrometry score in predicting renal mass radiofrequency ablation success.

OBJECTIVE: To assess the predictive performance of a modified RENAL nephrometry score for renal tumors undergoing radiofrequency ablation (RFA). METHODS: Patients who underwent RFA were identified from 2002 to 2011, and RENAL nephrometry scoring was performed for each. A modified RENAL (m-RENAL) nephrometry score was created to account for the small sizes of tumors ablated for which the size variable, R, was adjusted. A size of 3 cm was calculated as the optimal cutoff for the R component of the m-RENAL nephrometry score, and tumors were given an R score of 1 if <3 cm, 2 if 3-4 cm, or 3 if >4 cm. Other RENAL variables were unchanged. Oncologic outcomes were stratified by complexity tertiles defined as low (4-6), medium (7-9), and high (10-12). Outcomes were reported as initial ablation success (IAS), recurrence-free survival (RFS), and metastatic-free survival (MFS). The Kaplan-Meir method was used to estimate survival based on complexity tertile. RESULTS: Two hundred forty patients were identified who underwent RFA, of which 192 patients were eligible for analysis. Median follow-up was 32.2 months, and median tumor size was 2.4 cm. IAS was achieved in 185 of 192 patients (96.4%). Overall, the estimated 3-year RFS was 95.1% and MFS was 97.3%. There was no statistical difference between complexity tertiles using the standard RENAL nephrometry score; however, the m-RENAL nephrometry score was significantly associated with IAS and RFS (P = .027 and P = .003, respectively). There were too few events (n = 3) to perform statistical analysis for MFS. CONCLUSION: A modification to the size variable increases the performance of the RENAL nephrometry score when used to stratify RFA ablation success.

Prostate cancer detection using combined auto-fluorescence and light reflectance spectroscopy: ex vivo study of human prostates.

This study was conducted to evaluate the capability of detecting prostate cancer (PCa) using auto-fluorescence lifetime spectroscopy (AFLS) and light reflectance spectroscopy (LRS). AFLS used excitation at 447 nm with four emission wavelengths (532, 562, 632, and 684 nm), where their lifetimes and weights were analyzed using a double exponent model. LRS was measured between 500 and 840 nm and analyzed by a quantitative model to determine hemoglobin concentrations and light scattering. Both AFLS and LRS were taken on n = 724 distinct locations from both prostate capsular (nc = 185) and parenchymal (np = 539) tissues, including PCa tissue, benign peripheral zone tissue and benign prostatic hyperplasia (BPH), of fresh ex vivo radical prostatectomy specimens from 37 patients with high volume, intermediate-to-high-grade PCa (Gleason score, GS ≥7). AFLS and LRS parameters from parenchymal tissues were analyzed for statistical testing and classification. A feature selection algorithm based on multinomial logistic regression was implemented to identify critical parameters in order to classify high-grade PCa tissue. The regression model was in turn used to classify PCa tissue at the individual aggressive level of GS = 7,8,9. Receiver operating characteristic curves were generated and used to determine classification accuracy for each tissue type. We show that our dual-modal technique resulted in accuracies of 87.9%, 90.1%, and 85.1% for PCa classification at GS = 7, 8, 9 within parenchymal tissues, and up to 91.1%, 91.9%, and 94.3% if capsular tissues were included for detection. Possible biochemical and physiological mechanisms causing signal differences in AFLS and LRS between PCa and benign tissues were also discussed.

LESS and NOTES instrumentation: future.

PURPOSE OF REVIEW: Laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) are novel techniques with potential to minimize the morbidity of surgery. Challenging ergonomics, instrument clashing, and the lack of true triangluation still remain great concerns. RECENT FINDINGS: New technological developments in instrument design have been created to enhance clinical applicability of these techniques. Further technological advancements including the incorporation of novel robotic surgical platforms (R-LESS) exploit the ergonomic benefits in an attempt to further advance LESS surgery. Promising devices include magnetic anchoring and guidance systems that have the potential to allow external manoeuvring of intracorporeal instruments while facilitating triangulation and reducing clashing. As well, the benefit of miniature in-vivo robots that can be placed endoscopically intra-abdominally and controlled wirelessly will allow internal manipulation of tissue from internal repositionable platforms. SUMMARY: It remains to be seen whether LESS or NOTES will prove their clinical benefit over standard laparoscopic or robotic procedures. In this chapter, we review the current LESS and NOTES technology, and focus on new innovations and research in the field.

Evaluation of anatomic and morphologic nomogram to predict malignant and high-grade disease in a cohort of patients with small renal masses.

OBJECTIVE: To evaluate a nomogram using the RENAL Nephrometry Score (RENAL-NS) that was developed to characterize masses as benign vs. malignant and high vs. low grade in our patients with small renal masses treated with partial nephrectomy (PN). The nomogram was previously developed and validated in patients with widely variable tumor sizes. MATERIALS AND METHODS: Retrospective review of PN performed between 1/2003 and 7/2011. Imaging was reviewed by a urologic surgeon for RENAL-NS. Final pathology was used to classify tumors as benign or malignant and low (I/II) or high (III/IV) Fuhrman grade. Patient age, gender, and RENAL score were entered into the nomogram described by Kutikov et al. to determine probabilities of cancer and high-grade disease. Area under the curve was determined to assess agreement between observed and expected outcomes for prediction of benign vs. malignant disease and for prediction of high- vs. low-grade or benign disease. RESULTS: A total of 250 patients with 252 masses underwent PN during the study period; 179/250 (71.6%) had preoperative imaging available. RENAL-NS was assigned to 181 masses. Twenty-two percent of tumors were benign. Eighteen percent of tumors were high grade. Area under the curve was 0.648 for predicting benign vs. malignant disease and 0.955 for predicting low-grade or benign vs. high-grade disease. CONCLUSIONS: The RENAL-NS score nomogram by Kutikov does not discriminate well between benign and malignant disease for small renal masses. The nomogram may potentially be useful in identifying high-grade tumors. Further validation is required where the nomogram probability and final pathologic specimen are available.

Renal tumour nephrometry score does not correlate with the risk of radiofrequency ablation complications.

OBJECTIVES: To assess whether the R.E.N.A.L. nephrometry score (consists of [R]adius [tumour size as maximal diameter], [E]xophytic/endophytic properties of the tumour, [N]earness of tumour deepest portion to the collecting system or sinus, [A]nterior [a]/posterior [p] descriptor and the [L]ocation relative to the polar line) is associated with complication risk in patients that have radiofrequency ablation (RFA) for small renal masses (SRMs). To evaluate a standardised system for predicting complication risks which has not been studied. PATIENTS AND METHODS: We reviewed the records of all patients who underwent RFA at our institution between May 2001 and May 2011. RFA was performed using a temperature-based system and a 25-G nine-tine array needle probe. Patients with preoperative imaging available for R.E.N.A.L. nephrometry scoring were included. R.E.N.A.L. composite scores, tertile stratification and preoperative patient characteristics were analysed for significance in relation to complications. Complications were defined using the Clavien-Dindo classification system. RESULTS: In all, 199 patients had preoperative R.E.N.A.L. nephrometry scores available; 170 underwent percutaneous RFA and 29 laparoscopic RFA. The mean (range) American Society of Anesthesiologists (ASA) score was 2.6 (1-4). The mean (range) tumour size was 2.4 (0.7-5.4) cm. Overall, 14 complications were identified; 10 minor (Clavien I-II) and four major (Clavien III-IV). There was no significant association between complications and R.E.N.A.L. nephrometry score, R.E.N.A.L. nephrometry tertiles, tumour diameter, tumour location or ASA score (P > 0.05). CONCLUSION: R.E.N.A.L. nephrometry scoring fails to predict complications of RFA for SRMs when using a temperature-based nine-tine array probe.

A comparison of long term renal functional outcomes following partial nephrectomy and radiofrequency ablation.

INTRODUCTION: To compare long term glomerular filtration rate (GFR) outcomes of partial nephrectomy and radiofrequency ablation performed for renal malignancy. MATERIALS AND METHODS: Renal function of 347 patients undergoing radiofrequency ablation (n = 142) or partial nephrectomy (n = 205) for renal malignancy between 1994 and 2011 were compared from a retrospective database at a single tertiary care center. Minimum 1 year of follow up was required, resulting in a mean follow up of 48.2 (SD +/- 28.2) months. Renal function was estimated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The primary study outcome was progression of Chronic Kidney Disease (CKD) stage, calculated using the Kaplan-Meier life table method. Multivariate analysis was also conducted to determine the level of association between GFR decline and treatment modality. RESULTS: The 5 year freedom from CKD stage progression for radiofrequency ablation and partial nephrectomy was 85.4% (95% CI 76.8%-91.1%) versus 82.1% (95% CI 73.7%-88.1%) (p = 0.06). A longer follow up interval was associated with greater GFR decline, although hypertension, diabetes, age, and tumor size were not. CONCLUSION: Radiofrequency ablation provides similar long term renal function preservation benefit as partial nephrectomy.