Association of Baseline Magnetic Resonance Imaging Prostate Imaging Reporting and Data System Score With Prostate Cancer Active Surveillance Early Biopsy Reclassification: Data From the Michigan Urological Surgery Improvement Collaborative (MUSIC).

PURPOSE: The purpose of our study was to evaluate the association of baseline MRI Prostate Imaging Reporting and Data System (PI-RADS) score with biopsy reclassification in a multicenter active surveillance (AS) cohort. MATERIALS AND METHODS: We identified men in the Michigan Urological Surgery Improvement Collaborative registry (46 hospital-based/academic/private practice urology groups) with National Comprehensive Cancer Network (NCCN) low-risk and favorable intermediate-risk prostate cancer who underwent MRI within 6 months before or after initial biopsy and enrolled in AS from June 2016 to January 2021. The primary objective was to determine the association of baseline MRI PI-RADS score (≥4 lesion) with reclassification to high-grade prostate cancer (≥grade group 3) on surveillance biopsy. Multivariable Cox proportional hazards regression models were constructed and adjusted for pathologic, MRI, and clinical/biopsy factors, with landmark time of 6 months from diagnostic biopsy. We included an interaction term between PI-RADS score and NCCN group in the Cox model. RESULTS: A total of 1491 men were included with median age 64 years (IQR: 59-69) with median follow-up 11.0 months (IQR: 6.0-23.0) after landmark. Baseline PI-RADS ≥ 4 lesion was associated with an increased hazard of biopsy reclassification (HR: 2.3 [95% CI: 1.6-3.2], P < .001), along with grade group 2 vs 1 (HR: 2.5 [95% CI: 1.7-3.7], P < .001), and increasing age (per 10 years; HR: 1.8 [95% CI: 1.4-2.4], P < .001). The interaction between NCCN risk group with MRI findings was not significant (P = .7). CONCLUSIONS: In this multicenter cohort study of real-world data, baseline MRI PI-RADS score was significantly associated with early biopsy reclassification in men undergoing AS with NCCN low- or favorable intermediate-risk prostate cancer.

What Is the Optimal Stenting Duration After Ureteroscopy and Stone Intervention? Impact of Dwell Time on Postoperative Emergency Department Visits.

PURPOSE: AUA stone management guidelines recommend stenting duration following ureteroscopy be minimized to reduce morbidity; stents with extraction strings may be used for this purpose. However, an animal study demonstrated that short dwell time results in suboptimal ureteral dilation, and a pilot clinical study showed this increases postprocedure events. Using real-world practice data we examined stent dwell time after ureteroscopy and its association with postoperative emergency department visits. MATERIALS AND METHODS: We used the Michigan Urological Surgery Improvement Collaborative registry to identify ureteroscopy and stenting procedures (2016-2019). Pre-stented cases were excluded. Stenting cohorts with and without strings were analyzed. Using multivariable logistic regression we evaluated the risk of an emergency department visit occurring on the day of, or day after, stent removal based on dwell time and string status. RESULTS: We identified 4,437 procedures; 1,690 (38%) had a string. Median dwell time was lower in patients with a string (5 vs 9 days). Ureteroscopy in younger patients, smaller stones, or renal stone location had a higher frequency of string use. The predicted probability of an emergency department visit was significantly greater in procedures with string, compared to without string, when dwell times were less than 5 days (P < .01) but were not statistically significant after. CONCLUSIONS: Patients who had ureteroscopy and stenting with a string have short dwell times. Patients are at increased risk of a postoperative emergency department visit around the time of stent removal if dwell time is ≤4 days. We recommended stenting duration of at least 5 days in nonpre-stented patients.

Building a Roadmap for Surveillance of Renal Masses Using a Modified Delphi Method to Help Achieve Consensus.

OBJECTIVE: To establish a consensus for initial evaluation and follow-up of patients on active surveillance (AS) for T1 renal masses (T1RM). METHODS: A modified Delphi method was used to gather information about AS of T1RM, with a focus on patient selection, timing/type of imaging modality, and triggers for intervention. A consensus panel of Michigan Urological Surgery Improvement Collaborative-affiliated urologists who routinely manage renal masses was formed. Areas of consensus (defined >80% agreement) about T1RM AS were established iteratively via 3 rounds of online questionnaires. RESULTS: Twenty-six Michigan Urological Surgery Improvement Collaborative urologists formed the panel. Consensus was achieved for 321/587 scenarios (54.7%) administered through 124 questions. Life expectancy, age, comorbidity, and renal function were most important for patient selection, with life expectancy ranking first. All tumors <3 cm and all patients with life expectancy <1 year were considered appropriate for AS. Appropriateness also increased with elevated perioperative risk, increasing tumor complexity, and/or declining renal function. Consensus was for multiphasic axial imaging initially (contrast CT for GFR >60 or MRI for GFR >30) with first repeat imaging at 3-6 months and subsequent imaging timing determined by tumor size. Consensus was for chest imaging for tumors >3 cm initially and >5 cm at follow up. Renal biopsy was not felt to be a requirement for entering AS, but useful in several scenarios. Consensus indicated rapid tumor growth as an appropriate trigger for intervention. CONCLUSION: Our consensus panel was able to achieve areas of consensus to help define a clinically useful and specific roadmap for AS of T1RM and areas for further discussion where consensus was not achieved.

Real-world Practice Stone-free Rates After Ureteroscopy: Variation and Outcomes in a Surgical Collaborative.

BACKGROUND: Studies assessing the stone-free rate (SFR) after ureteroscopy are limited to expert centers with varied definitions of stone free. Real-world data including community practices related to surgeon characteristics and outcomes are lacking. OBJECTIVE: To evaluate the SFR for ureteroscopy and its predictors across diverse surgeons in Michigan. DESIGN, SETTING, AND PARTICIPANTS: We assessed the Michigan Urological Surgery Improvement Collaborative (MUSIC) clinical registry for patients with renal or ureteral stones treated with ureteroscopy between 2016 and 2021 who had postoperative imaging. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Stone free was defined as no fragments on imaging reports within 60 d entered by independent data abstractors. Factors associated with being stone free were examined using logistic regression, including annual surgeon volume. We then assessed variation in surgeon-level SFRs adjusted for risk factors. RESULTS AND LIMITATIONS: We identified 6487 ureteroscopies from 164 surgeons who treated 2091 (32.2%) renal and 4396 (67.8%) ureteral stones. The overall SFRs were 49.6% (renal) and 72.7% (ureteral). Increasing stone size, lower pole, proximal ureteral location, and multiplicity were associated with not being stone free. Female gender, positive urine culture, use of ureteral access sheath, and postoperative stenting were associated with residual fragments when treating ureteral stones. Adjusted surgeon-level SFRs varied for renal (26.1-72.4%; p < 0.001) and ureteral stones (52.2-90.2%; p < 0.001). Surgeon volume was not a predictor of being stone free for renal stones. Limitations include the lack of imaging in all patients and use of different imaging modalities. CONCLUSIONS: The real-world complete SFR after ureteroscopy is suboptimal with substantial surgeon-level variation. Interventions focused on surgical technique refinement are needed to improve outcomes for patients undergoing ureteroscopy and stone intervention. PATIENT SUMMARY: Results from a diverse group of community practicing and academic center urologists show that for a large number of patients, it is not possible to be completely stone free after ureteroscopy. There is substantial variation in surgeon outcomes. Quality improvement efforts are needed to address this.

Stent Omission in Pre-stented Patients Undergoing Ureteroscopy Decreases Unplanned Health Care Utilization.

INTRODUCTION: Despite AUA guidelines providing criteria for ureteral stent omission after ureteroscopy for nephrolithiasis, stenting rates in practice remain high. Because pre-stenting may be associated with improved patient outcomes, we assessed the impact of stent omission vs placement in pre-stented and non-pre-stented patients undergoing ureteroscopy on postoperative health care utilization in Michigan. METHODS: Using the MUSIC (Michigan Urological Surgery Improvement Collaborative) registry (2016-2019), we identified pre-stented and non-pre-stented patients with low comorbidity undergoing single-stage ureteroscopy for ≤1.5 cm stones with no intraoperative complications. We assessed variation in stent omission for practices/urologists with ≥5 cases. Using multivariable logistic regression, we evaluated whether stent placement in pre-stented patients was associated with emergency department visits and hospitalizations within 30 days of ureteroscopy. RESULTS: We identified 6,266 ureteroscopies from 33 practices and 209 urologists, of which 2,244 (35.8%) were pre-stented. Pre-stented cases had higher rates of stent omission vs non-pre-stented cases (47.3% vs 26.3%). Among the 17 urology practices with ≥5 cases, stent omission rates in pre-stented patients varied widely (0%-77.8%). Among the 156 urologists with ≥5 cases, stent omission rates in pre-stented patients varied substantially (0%-100%); 34/152 (22.4%) never performed stent omission. Adjusting for risk factors, stent placement in pre-stented patients was associated with increased emergency department visits (OR 2.24, 95% CI:1.42-3.55) and hospitalizations (OR 2.19, 95% CI:1.12-4.26). CONCLUSIONS: Pre-stented patients undergoing stent omission after ureteroscopy have lower unplanned health care utilization. Stent omission is underutilized in these patients, making them an ideal group for quality improvement efforts to avoid routine stent placement after ureteroscopy.

Impact of the bladder detrusor muscular ring on lower urinary tract symptoms due to benign prostatic hyperplasia: A quantitative MRI analysis.

BACKGROUND: The etiology of lower urinary tract symptoms secondary to benign prostatic hyperplasia (LUTS/BPH) remains uncertain. OBJECTIVE: The purpose of our study was to quantitatively analyze anatomic characteristics on magnetic resonance imaging (MRI) to assess novel independent factors for symptoms. METHODS: This retrospective single-institution study evaluated treatment-naïve men who underwent prostate MRI within 3 months of international prostate symptom score (IPSS) scoring from June 2021 to February 2022. Factors measured on MRI included: size of the detrusor muscular ring (DMR) surrounding the bladder outlet, central gland (CG) mean apparent diffusion coefficient (ADC), levator hiatus (LH) volume, intrapelvic volume, intravesicular prostate protrusion (IPP) volume, CG volume, peripheral zone (PZ) volume, prostate urethra angle (PUA), and PZ background ordinal score. Multivariable logistic regression and receiver operating characteristic analysis were used to analyze factors for moderate/severe (IPSS ≥ 8) and severe LUTS/BPH (IPSS ≥ 20). RESULTS: A total of 303 men (mean age: 66.1 [SD: 8.1]) were included: 154 demonstrated moderate or severe symptoms with 28 severe and 149 with asymptomatic/mild symptoms. Increasing age [p = 0.02; odds ratio (OR): 1.05 (1.01-1.08)], PUA [p = 0.02; OR: 1.05 (1.01-1.09)], LH volume [p = 0.04; OR: 1.02 (1.00-1.05)], and DMR size measured as diameter [p < 0.001; OR: 5.0 (3.01-8.38)] or area [p < 0.001; OR: 1.92 (1.47-2.49)] were significantly independently associated with moderate/severe symptoms, with BMI [p = 0.02; OR: 0.93 (0.88-0.99)] inversely related. For every one cm increase in DMR diameter, patients had approximately five times the odds for moderate/severe symptoms. Increasing DMR size [diameter p < 0.001; OR: 2.74 (1.76-4.27) or area p < 0.001; OR: 1.37 (1.18-1.58)] was independently associated with severe symptoms. Optimal criterion cutoff of DMR diameter for moderate/severe symptoms was 1.2 cm [sensitivity: 77.3; specificity: 71.8; AUC: 0.80 (0.75-0.84)]. Inter-reader reliability was excellent for DMR diameter [ICC = 0.92 (0.90-0.94)]. CONCLUSION: Expansion of the DMR surrounding the bladder outlet is a novel anatomic factor independently associated with moderate and severe LUTS/BPH, taking into account prostate volumes, including quantified IPP volume, which were unrelated. Detrusor ring diameter, easily and reliably measured on routine prostate MRI, may relate to detrusor dysfunction from chronic stretching of this histologically distinct smooth muscle around the bladder neck.

Development of a Surgical Decision Aid for Patients with Nephrolithiasis: Shockwave Lithotripsy vs Ureteroscopy.

Introduction and Objective: Shared decision making is recommended to guide medical/surgical treatment strategies. We aimed at developing a surgical decision aid (SDA) facilitating decision making between ureteroscopy (URS) or shockwave lithotripsy (SWL) in patients with symptomatic nephrolithiasis. Methods: The SDA scope was identified through discussions with patients and urologists in the Michigan Urological Surgery Improvement Collaborative (MUSIC). A steering committee of patient advocates, MUSIC coordinating center, content experts, biostatisticians, and urologists was formed. Content domains were assessed through best available evidence and content experts. For content validation we anonymously surveyed 35 MUSIC urologists. Content validity ratios (CVR), numeric value indicating degree of expert validity, were calculated. Face validation interviews were conducted with patient advocates. Results: The SDA prototype using descriptive plain language and pictorial information was designed for nephrolithiasis patients, candidates for SWL or URS. It first provides patients procedural education whereas the second section informs urologists of patient goals. Six content domains were chosen: anesthesia type, effectiveness, number of procedures, risk, pain, and recovery. Overall, 91.4% and 85.7% of MUSIC urologists indicated that each section accomplished their goals, respectively. Anesthesia received an unacceptable CVR. High levels of face validation overall were reported with unacceptable scoring for anesthesia and recovery. Conclusions: We developed an SDA facilitating treatment choice between SWL and URS with promising content and face validity. Agreement and contradiction between anesthesia type and recovery validation results indicate the importance of shared decision making and the need for a validated SDA. Future work should focus on the SDAs value and opportunities for refinement in practice.

Which measurement method should be used for prostate volume for PI-RADS? A comparison of ellipsoid and segmentation methods.

PURPOSE: Prostate volume and PSA density (PSAd) are important in the risk stratification of suspected prostate cancer (Pca). PI-RADS v2.1 allows for determining volume via segmentation or ellipsoid calculation. The purpose of our study was to compare ellipsoid and segmentation volume calculation methods and evaluate if PSAd diagnostic performance is altered. METHODS: We retrospectively assessed 397 patients (mean age/standard deviation: 63.7/7.4 years) who underwent MRI and prostate biopsy or prostatectomy, with Pca classified by Gleason ≥3 + 4 and ≥4 + 4 disease. Prostate total volumes were determined with ellipsoid calculations (TVe) and with semi-automated segmentation (TVs), along with inter-rater reliability with intraclass correlation coefficient (ICC). PSAd was calculated for TVe and TVs and ROC curves were created to compare performance for Gleason ≥3 + 4 and ≥4 + 4 disease. RESULTS: TVe was significantly higher than TVs (p < 0.0001), with mean TVe = 55.4 mL and TVs = 51.0 mL. ROC area under the curve for PSAd derived with TVe (0.63, 95%CI:0.59-0.68) and TVs (0.64, 95%CI:0.59-0.68) showed no significant difference for Gleason ≥3 + 4 disease (p = 0.45), but PSAd derived with TVs (0.63, 95%CI: 0.58-0.68) significantly outperformed TVe (0.61, 95%CI: 0.57-0.67) for Gleason ≥4 + 4 disease (p = 0.02). Both methods demonstrated excellent inter-rater reliability with TVe with ICC of 0.93(95%CI: 0.92-0.94) and TVs with ICC of 0.98(95%CI: 0.98-0.99). CONCLUSION: Traditional ellipsoid measurements tend to overestimate total prostate volume compared to segmentation, but both methods demonstrate similar diagnostic performance of derived PSA density for PI-RADS clinically significant disease. For higher grade disease, PSAd derived from segmentation volumes demonstrates statistically significant superior performance. Both methods are viable, but segmentation volume is potentially better.

Benign prostate hyperplasia as a potential protective factor against prostate cancer: Insights from a magnetic resonance imaging study of compositional characteristics.

PURPOSE: The structural relationship between benign prostate hyperplasia (BPH) and prostate cancer (Pca) is controversial. The purpose of our study was to examine the association between quantitative prostate compositional metrics by magnetic resonance imaging (MRI) and Pca. METHODS: We identified 405 patients who underwent prostate MRI and biopsy and/or prostatectomy from January 2019 to January 2021 at our institution. Segmentation volumetric methods were used to assess central gland (CG) and peripheral zone (PZ) volume. PZ mean thickness and mean apparent diffusion coefficient (ADC), marker of underlying histologic components, were measured. Multivariable logistic regression was performed with outcomes of ≥Grade Group (GG) 2 Pca and for multifocal disease. RESULTS: On multivariable analysis, higher CG volumes were at lower odds of ≥GG2 disease (n = 227) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001), taking into account PZ volume (p = 0.18) and thickness (p = 0.70). For every one cc increase in CG volume, there was an approximately 3% decrease in odds of ≥GG2 disease. Similar findings were noted for multifocal disease (n = 180) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001). Notably, ADC of the normal PZ was not significantly associated with CG volume (p = 0.21) nor a predictor of disease (p = 0.49). CONCLUSIONS: Increasing central gland volume, driven by BPH, is associated with lower odds of significant Pca, including multifocal disease, while PZ anatomic and histologic surrogate changes were noncontributory. Findings support BPH impediment of global tumor growth predicted by theoretical mechanobiological model. This potential stabilizing factor should be further studied for risk stratification and in consideration for BPH therapy.

Partial nephrectomy should be classified as an inpatient procedure: Results from a statewide quality improvement collaborative.

OBJECTIVES: To examine length of stay (LOS) and readmission rates for all minimally-invasive partial nephrectomy (MIPN) and MI radical nephrectomy (MIRN) performed for localized renal masses ≤7 cm in size (cT1RM) within 12 Michigan urology practices. Both RN and PN are commonly performed in treating cT1RM. Although technically more complex and associated with higher complication rates, Centers for Medicare & Medicaid Services considers MIPN an outpatient procedure and MIRN is inpatient. METHODS: We collected data for renal surgeries for cT1RM at MUSIC-KIDNEY practices between May 2017-February 2020. Data abstractors recorded clinical, radiographic, pathologic, surgical, and short-term follow-up data into the registry for cT1RM patients. RESULTS: Within MUSIC-KIDNEY, 807 patients underwent MI renal surgery at 12 practices. Median LOS for cT1RM patients after MIPN (n = 531, 66%) was 2 days and after MIRN (n = 276, 34%) was also 2 days. Among patients undergoing laparoscopic or robotic PN, 171 (32%), 230 (43%), and 130 (24%) stayed ≤1, 2, ≥3 days. Among patients undergoing laparoscopic or robotic RN, 81 (29%), 112 (41%), and 83 (30%) stayed ≤1, 2, ≥3 days. No significant difference was observed between MIPN and MIRN on LOS commensurate with outpatient surgery (≤1-day, OR = 0.97, P = 0.87). CONCLUSIONS: Less than one-third of patients had a LOS ≤1-day and LOS was comparable for MIPN and MIRN. Centers for Medicare & Medicaid Services should be advised that MIPN is a more complex surgery than MIRN, most patients receiving a MIPN will require a ≥2-day hospital stay and it would be more appropriate to classify MIPN an inpatient procedure with MIRN.

Infection-related hospitalization following ureteroscopic stone treatment: results from a surgical collaborative.

BACKGROUND: Unplanned hospitalization following ureteroscopy (URS) for urinary stone disease is associated with patient morbidity and increased healthcare costs. To this effect, AUA guidelines recommend at least a urinalysis in patients prior to URS. We examined risk factors for infection-related hospitalization following URS for urinary stones in a surgical collaborative. METHODS: Reducing Operative Complications from Kidney Stones (ROCKS) is a quality improvement (QI) initiative from the Michigan Urological Surgery Improvement Collaborative (MUSIC) consisting of academic and community practices in the State of Michigan. Trained abstractors prospectively record standardized data elements from the health record in a web-based registry including patient characteristics, surgical details and complications. Using the ROCKS registry, we identified all patients undergoing primary URS for urinary stones between June 2016 and October 2017, and determined the proportion hospitalized within 30 days with an infection-related complication. These patients underwent chart review to obtain clinical data related to the hospitalization. Multivariable logistic regression analysis was performed to determine risk factors for hospitalization. RESULTS: 1817 URS procedures from 11 practices were analyzed. 43 (2.4%) patients were hospitalized with an infection-related complication, and the mortality rate was 0.2%. Median time to admission and length of stay was 4 and 3 days, respectively. Nine (20.9%) patients did not have a pre-procedure urinalysis or urine culture, which was not different in the non-hospitalized cohort (20.5%). In hospitalized patients, pathogens included gram-negative (61.5%), gram-positive (19.2%), yeast (15.4%), and mixed (3.8%) organisms. Significant factors associated with infection-related hospitalization included higher Charlson comorbidity index, history of recurrent UTI, stone size, intra-operative complication, and procedures where fragments were left in-situ. CONCLUSIONS: One in 40 patients are hospitalized with an infection-related complication following URS. Awareness of risk factors may allow for individualized counselling and management to reduce these events. Approximately 20% of patients did not have a pre-operative urine analysis or culture, and these findings demonstrate the need for further study to improve urine testing and compliance.

Variable Use of Postoperative Imaging Following Ureteroscopy: Results from a Statewide Quality Improvement Collaborative.

OBJECTIVE: To understand patient and practice-level factors impacting postoperative imaging use after ureteroscopy (URS) for urinary stone disease. METHODS: The Michigan Urological Surgery Improvement Collaborative's Reducing Operative Complications from Kidney Stones (MUSIC ROCKS) initiative is a consortium of 52 urologists from 11 practices in Michigan. From June 2016 to July 2017, we prospectively collected clinical data for patients undergoing URS for stone treatment by MUSIC ROCKS participants. We measured the proportion of these patients who underwent US, AXR, and/or CT within the first 60 days after their procedure. We then assessed variation in the use of post-URS imaging according to patient characteristics and across MUSIC ROCKS practices. RESULTS: During the 13-month study period, we identified 2850 patients who were treated with URS for stone disease. Overall, only 47.6% of these patients underwent postoperative imaging. AXR was the most common modality used (55.0% of patients), followed by US (21.9%) and CT (11.1%). As shown in the Figure, use of post-URS imaging varied widely across participating practices (23.7%-73.6%; P <.01). Imaging receipt did not differ by patient age, gender, or insurance status. However, patients with more comorbidities, renal stones and those with larger stones were more likely to receive post-URS imaging (P <.05 for each comparison). CONCLUSION: Fewer than half of patients in Michigan undergo postoperative imaging after URS for stone disease. Moreover, there is substantial variation across providers in post-URS imaging use. These findings help identify opportunities to improve the quality of care for patients with urinary stone disease in the State.

A Retrospective Comparative Outcomes and Cost Analysis of Office Based, Ultrasound Guided Renal Mass Biopsy Performed by Urologists and Standard Hospital Biopsies for Small Renal Masses.

INTRODUCTION: Renal mass biopsy is useful in the evaluation of small renal masses. We have previously reported that office based, ultrasound guided renal mass biopsy is safe, effective and feasible when performed by urologists. This study compares office based, ultrasound guided renal mass biopsy performed by urologists and hospital based renal mass biopsy. METHODS: We retrospectively studied 70 patients who underwent office based, ultrasound guided renal mass biopsy and 155 who underwent hospital based, ultrasound or computerized tomography guided renal mass biopsy for evaluation of a small renal mass (4.0 cm or less) between January 2010 and February 2016. RESULTS: A total of 70 patients underwent office based, ultrasound guided renal mass biopsy. Median age in this group was 69.5 years, median body mass index was 29.5 kg/m2 and 61.4% of the patients (43) were male. A total of 103 patients underwent hospital based, ultrasound guided biopsy. Median age in this group was 68.0 years, median body mass index was 29.3 kg/m2 and 53.4% of the patients (55) were male. Finally, 52 patients underwent hospital based, computerized tomography guided biopsy. Median age in this group was 69 years, median body mass index was 30.1 kg/m2 and 51.9% of the patients (27) were male. Median tumor size was 2.7 cm in patients undergoing office based, ultrasound guided renal mass biopsy, 2.2 cm in those undergoing hospital based, ultrasound guided biopsy and 2.1 cm in those undergoing hospital based, computerized tomography guided biopsy (p = 0.001). Renal cell carcinoma was found in 43 of 70 (61.4%), 74 of 103 (71.8%) and 33 of 52 (63.5%) respective biopsies. Respective diagnostic rates were 81.4% (57 of 70 cases), 88.3% (91 of 103) and 86.5% (45 of 52, p = 0.434). Concordance with surgical pathology was 97.7% (42 of 43 cases), 100% (35 of 35) and 100% (15 of 15), respectively. Complication rates were 4.3% (3 of 70 patients), 13.6% (14 of 103) and 13.5% (7 of 52), respectively (p = 0.096). Cost analysis revealed that when available, office based, ultrasound guided renal mass biopsy provides the health care system a total savings of approximately $46,011 yearly. CONCLUSIONS: Office based, ultrasound guided renal mass biopsy for small renal masses is a safe and efficacious option for select patients, and potentially offers greater convenience and availability as well as decreased health care costs.

Completely Isolated Retroperitoneal Enteric Duplication Cyst with Adenocarcinoma Transformation Managed with Robotic Radical Nephrectomy.

Background: Enteric duplication cysts are congenital malformations that typically affect children in infancy, but can also affect adults. Rarely, these cysts can be complicated by malignancy. We present the first case of retroperitoneal duplication cyst that was complicated by malignancy transformation and managed by robot-assisted excision. Case presentation: A 64-year-old female with a history of a left-sided renal cyst presented with a 4-month history of abdominal pain and fatigue. MRI revealed a bilobed cyst, with components measuring 6.9 × 6.6 and 6.1 × 6.9 cm, which had grown since previous imaging, and hemorrhage in some portions of the cysts, as well as cystic wall enhancement, suggesting a possible malignancy. The patient consented to a robot-assisted partial (possible radical) nephrectomy. During the procedure, the cystic structure appeared to have grown since imaging, was intimately associated with the hilum, and had a complex vasculature, which prompted us to perform a radical nephrectomy. Grossly, the specimen consisted of a 14.8 cm cystic structure at the superior portion of the kidney, but was not contained within the renal parenchyma. Histologically, the internal mucosa of the cyst showed columnar epithelium with high-grade dysplasia and carcinoma in situ with focal individual cell infiltration into the superficial portion of the inferior part of the cyst. The patient saw a medical oncologist and was instructed to follow up with quarterly imaging to assess for disease progression. Conclusion: Enteric duplication cysts are uncommon entities that can occur in various locations in the body, causing a wide spectrum of symptoms, and are rarely complicated by malignancy transformation. Robot-assisted surgical resection is an option that we have shown to be effective in managing these patients.

Office-based Ultrasound-guided Renal Core Biopsy Is Safe and Efficacious in the Management of Small Renal Masses.

OBJECTIVE: To evaluate the safety and efficacy of ultrasound (US)-guided percutaneous renal mass biopsy (RMB) performed in the office setting by urologists. MATERIALS AND METHODS: This is a retrospective study involving patients who underwent office-based US-guided percutaneous RMB between April 2010 and October 2015. Baseline vital signs and US were performed prior to the procedure. Patients were then observed for 1 hour after the procedure and repeat vital signs and US were performed. Hemodynamically stable patients who did not develop hematoma were discharged. RESULTS: In 108 patients, 70 (64.8%) were male, median age was 69.5 years, and median mass size was 3.3 cm (interquartile range: 2.5-4.6). Biopsy yield was as follows: 72 (66.7%) had renal cell carcinoma, 14 (13.0%) had benign renal parenchyma, 11 (10.2%) had oncocytoma, 6 (5.6%) had angiomyolipoma, 2 (1.9%) had lymphoma, and 3 (2.8%) had other disease. The initial nondiagnostic rate was 14 of 108 (13.0%). There were 28 of 108 (25.9%) patients observed whereas 79 of 108 (73.2%) received surgery or ablative therapy. Final pathology was concordant with biopsy results in 66 of 68 (97.1%) cases. Three patients experienced a grade I Clavien-Dindo surgical complication, all of which were managed conservatively. CONCLUSION: Office-based US-guided RMB is safe and efficacious in the management of appropriately selected SRM. It potentially offers improved dynamic characterization of solid renal mass, greater convenience to patients, as well as cost savings. Further studies are needed to evaluate this promising technique.

Percutaneous Cryoablation vs Partial Nephrectomy: Cost Comparison of T1a Tumors.

PURPOSE: To compare cost of percutaneous cryoablation vs open and robot-assisted partial nephrectomy of T1a renal masses from the hospital perspective. MATERIALS AND METHODS: We retrospectively compared cost, clinical and tumor data of 37 percutaneous cryoablations to 26 open and 102 robot-assisted partial nephrectomies. Total cost was the sum of direct and indirect cost of procedural and periprocedural variables. Clinical data included demographics, Charlson Comorbidity Index (CCI), hospitalization time, complication rate, ICU admission rate, and 30-day readmission rates. Tumor data included size, RENAL nephrometry score, and malignancy rate. Student's t-test was used for continuous variables and Fisher's exact or chi-square tests for categorical data. RESULTS: Mean total cost was lower for percutaneous cryoablation than open or robot-assisted partial nephrectomy: $6067 vs $11392 or $11830 (p<0.0001) with lower cost of procedure room: $1516 vs $3272 or $3254 (p<0.0001), room and board: $95 vs $1907 or $1106 (p<0.0001), anesthesia: $684 vs $1223 or $1468 (p<0.0001), and laboratory/pathology fees: $205 vs $804 or $720 (p<0.0001). Supply and device cost was higher than open: $2596 vs $1352 (p<0.0001), but lower than robot-assisted partial nephrectomy: $3207 (p=0.002). Mean hospitalization times were lower for percutaneous cryoablation (p<0.0001), while age and CCI were higher (p<0.0001). No differences in tumor size, nephrometry score, malignancy rate complication, ICU, or 30-day readmission rates were observed. CONCLUSION: Percutaneous cryoablation can be performed at significantly lower cost than open and robotic partial nephrectomies for similar masses.

Urine kidney injury molecule-1: a potential non-invasive biomarker for patients with renal cell carcinoma.

BACKGROUND: KIM-1 staining is upregulated in proximal tubule-derived renal cell carcinoma (RCC) including clear renal cell carcinoma and papillary renal cell carcinoma, but not in chromophobe RCC (distal tubular tumor). This study was designed to prospectively examine urine KIM-1 level before and 1 month after removal of renal tumors. PATIENTS AND DESIGN: A total of 19 patients were eventually enrolled in the study based on pre-operative imaging studies. Pre-operative and follow-up (1 month) urine KIM-1 levels were measured. The urine KIM-1 levels (uKIM-1) were then normalized to urine creatinine levels (uCr). Renal tumors were also stained for KIM-1 using immunohistochemical techniques. RESULTS: The KIM-1-negative staining group included 7 cases, and the KIM-1-positive group consisted of 12 cases. The percentage of KIM-1-positive staining RCC cells ranged from 10 to 100 %, and the staining intensity ranged from 1+ to 3+. In both groups, serum creatinine levels were both significantly elevated after nephrectomy. In the KIM-1-negative group, uKIM-1/uCr remained at a similar level before (0.37 ± 0.1 ng/mg Cr) and after nephrectomy (0.32 ± 0.01 ng/mg Cr). However, in the KIM-1-positive group, elevated uKIM-1/uCr at 1.20 ± 0.31 ng/mg Cr was significantly reduced to 0.36 ± 0.1 ng/mg Cr, which was similar to the pre-operative uKIM-1/uCr (0.37 ± 0.1 ng/mg Cr) in the KIM-1-negative group. CONCLUSION: Our small but prospective study showed significant reduction in uKIM-1/uCr after nephrectomy in the KIM-1 positive group, suggesting that urine KIM-1 may serve as a surrogate biomarker for kidney cancer and a non-invasive pre-operative measure to evaluate the malignant potential of renal masses.

Cone beam computed tomography: an assessment of renal image quality and applicability for percutaneous renal cryotherapy in a swine model.

OBJECTIVES: To assess cone bean computed tomography (CBCT) for renal imaging in a phantom model, ex vivo kidney and an in vivo porcine percutaneous renal cyroablation (PRC). CBCT provides 3-dimensional sectional imaging without the space requirements, repositioning, and expenditure of computed tomography (CT). METHODS: CBCT was focused on a radiological phantom with electron density of renal tissue and visualization was recorded. The ability of CBCT to image an ex vivo kidney in a water bath, with and without contrast, was then evaluated. An in vivo porcine animal model was then used to perform PRC and the scanner was evaluated in regard to image of the kidneys, a fiber-agarose pseudotumor, and guidance of the cryoprobe. RESULTS: Qualitative assessment of phantom images revealed sufficient contrast between the renal tissue and water densities. Images of the ex vivo porcine kidneys without contrast revealed limited renal architecture, whereas retrograde contrast revealed 3D images of renal shape and vascular/collecting system architecture visible in axial and sagittal planes. Noncontrast imaging facilitated precise needle guidance but was inadequate to consistently visualize ice-ball formation during cryoablation. At necropsy, all tumors were encompassed by the cryolesion with >1-cm margins, except for 1 pseudotumor that had been placed extracapsularly. CONCLUSIONS: CBCT is an imaging modality capable of excellent spatial resolution and soft-tissue sensitivity in a radiographic phantom and ex vivo and in situ porcine renal models. Based on our preliminary results, further refinements in image quality are required to improve soft tissue visualization to be applied to percutaneous renal cryoablation.

Insight into current surgical techniques and practice patterns associated with robotic-assisted radical prostatectomy: a national survey of urologists within the USA.

Robotic-assisted radical prostatectomy (RARP) has been rapidly adopted throughout the USA. The purpose of this study is to describe the prevailing RARP operative techniques and perceptions within the USA. An anonymous web-based survey was sent electronically to a list of 920 robotic urological surgeons. The survey assessed surgeon demographics, surgical technique, and postoperative care related to RARP. The study was comprised of urologists from community hospitals (76%) and university hospitals/specialty centers (24%). All geographic sections of the American Urological Association were represented. The most common neurovascular preservation techniques were ante/retrograde approach (48%), athermal (22%), and preservation of lateral pelvic fascia (17%). Surgeon choice of neurovascular preservation technique varied with the average number of procedures performed per year (P = 0.0065). High-volume surgeons tended to require a higher number of robotic cases in order to go through the learning curve of the "comfortable" (P = 0.001) and "expert" levels (P < 0.0001). The majority of surgeons reported that RARP (as compared with open surgery) improved urinary continence (77.2%), sexual function (65.6%), and surgical margin rates (53.8%). RARP is an evolving surgical procedure with significant variability in practice patterns among US surgeons. Further studies are necessary to compare the various techniques in order to improve surgical outcomes.

Fibrin glue v sutured bolster: lessons learned during 100 laparoscopic partial nephrectomies.

PURPOSE: Laparoscopic partial nephrectomy (LPN) is performed with marked technical variations. We defined the limits of sutureless LPN and determined which closure technique is best in a particular situation. MATERIALS AND METHODS: During 100 consecutive LPNs fibrin glue products were used for closure in the first 75 (group 1) and sutured bolsters were applied when the collecting system (CS) or renal sinus was entered in the final 25 (group 2). RESULTS: In groups 1 and 2 hand assisted laparoscopy was used in 72% vs 40% of cases and hilar clamping was used in 27% vs 92%, respectively. Mean tumor size was 25 vs 26 mm, tumor depth was 11 vs 13 mm, distance to the renal sinus was 9 vs 5 mm, operating room time was 185 vs 210 minutes, estimated blood loss was 398 vs 247 cc and hospital stay was 2.9 vs 2.6 days in groups 1 and 2, respectively. Overall postoperative hemorrhage and urine leakage occurred in 9% and 2% of patients, respectively. Tumors associated with postoperative hemorrhage/leakage tended to be larger (35 vs 24 mm, p = 0.007) and closer to the renal sinus (0.5 vs 8.2 mm, p = 0.02). Postoperative hemorrhage or urine leakage occurred in 41% of the 17 patients in group 1 with CS or renal sinus entry but in only 2 of the 58 (3.4%) without entry (p <0.0001). In group 2 hemorrhage/leakage occurred in 11% of the 18 patients with CS or renal sinus entry (vs same subset in group 1, p = 0.04). CONCLUSIONS: LPN with closure using fibrin glue products provides adequate hemostasis when the CS or renal sinus is not entered. When the CS or renal sinus is entered, a sutured bolster is recommended.