Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy.

Acute kidney injury (AKI) is a common postoperative outcome in urology patients undergoing surgery for nephrolithiasis. The objective of this study was to determine the prevalence of postoperative AKI and its degrees of severity, identify risk factors, and understand the resultant outcomes of AKI in patients with nephrolithiasis undergoing percutaneous nephrolithotomy (PCNL). A cohort of patients admitted between 2012 and 2019 to a single tertiary-care institution who had undergone PCNL was retrospectively analyzed. Among 417 (n = 326 patients) encounters, 24.9% (n = 104) had AKI. Approximately one-quarter of AKI patients (n = 18) progressed to Stage 2 or higher AKI. Hypertension, peripheral vascular disease, chronic kidney disease, and chronic anemia were significant risk factors of post-PCNL AKI. Corticosteroids and antifungals were associated with increased odds of AKI. Cardiovascular, neurologic complications, sepsis, and prolonged intensive care unit (ICU) stay percentages were higher in AKI patients. Hospital and ICU length of stay was greater in the AKI group. Provided the limited literature regarding postoperative AKI following PCNL, and the detriment that AKI can have on clinical outcomes, it is important to continue studying this topic to better understand how to optimize patient care to address patient- and procedure-specific risk factors.

The Duration of Stone Disease and the Impact of a Stone Event on Patients' Quality of Life.

Introduction: With a 5-year stone recurrence rate of 30% to 50%, kidney stone formers are subject to significant morbidity that negatively impacts their health-related quality of life (HRQOL). We sought to determine the impact of age at kidney stone onset, duration of stone disease, and kidney stone event (surgery or stone passage) on HRQOL of individual patients by querying the validated and prospectively collected Wisconsin Stone Quality of Life (WISQOL) database. Patients and Methods: Cross-sectional data were obtained from a total of 2438 kidney stone formers from 14 institutions in North America who completed the WISQOL questionnaire during the period from 2014 to 2019. The 28-question survey has a 1- to 5-point scale for each item (total score range 0-140). Multivariable linear regression models assessed the impact of age at kidney stone onset, duration of stone disease, and time since most recent surgery or stone passage on HRQOL. Results: Of 2438 patients, older age at kidney stone onset and longer duration of disease were both independent predictors of better WISQOL scores (ß = 0.33 points/year; confidence interval [CI] 0.17-0.49; p < 0.001; and ß = 0.50 points/year; CI 0.32-0.68; p < 0.001, respectively). Of 1376 patients who underwent surgery between 2010 and 2019, longer time since most recent surgery was an independent predictor of better WISQOL scores (ß = 2.28 points/year; CI: 1.47-3.10; p = <0.001). Of 1027 patients with spontaneous stone passage occurring between 2010 and 2019, longer time since most recent stone passage was an independent predictor of better WISQOL scores (ß = 1.59 points/year; CI: 0.59-2.59; p = <0.05). Conclusions: Our study demonstrates that older age at onset, longer duration of disease, and longer time since most recent surgery or stone passage were independent predictors of better HRQOL in kidney stone formers. Results of future studies that focus on optimizing stone-related modifiable risk factors to decrease the number of recurrent stone episodes and thus the need for recurrent surgeries will be essential.

The Impact of Ureteral Access Sheath Use on the Development of Abnormal Postoperative Upper Tract Imaging after Ureteroscopy.

PURPOSE: Ureteral access sheaths are commonly used during ureteroscopy to facilitate stone removal, improve visibility and maintain low intrarenal pressures. However, the use of a ureteral access sheath can cause ureteral wall ischemia and ureteral tears, potentially increasing the risk of postoperative ureteral stricture and obstruction. We studied the impact of ureteral access sheath use on postoperative imaging studies. Secondary objectives included studying the impact of other intraoperative parameters on postoperative imaging studies. MATERIALS AND METHODS: A retrospective chart review was conducted of cases that underwent ureteroscopy for nephroureterolithiasis across 2 high volume institutions between January 2012 and September 2016. Patient demographics, cumulative stone size, operative time, use of ureteral access sheath, laser lithotripsy, basket extraction, preoperative ureteral stent and postoperative ureteral stent placement were extracted from the electronic medical record. Findings of followup renal ultrasound, kidney-ureter-bladder x-ray and/or computerized tomography at approximately 8 weeks after surgery were recorded. RESULTS: A total of 1,332 ureteroscopies were performed with 1,060 cases (79.6%) returning for routine upper tract imaging after ureteroscopy. Postoperative hydronephrosis was noted following 127 cases (12.0%). Factors predicting presence of hydronephrosis after ureteroscopy include lower body mass index (p=0.0016), greater cumulative stone size (p=0.0003), increased operative time (p <0.0001), preoperative ureteral stent (OR 1.49, p=0.0299) and postoperative ureteral stent placement (OR 6.43, p=0.0031). Postoperative hydronephrosis was not associated with use of ureteral access sheath, age, laser lithotripsy or basket extraction. CONCLUSIONS: Use of ureteral access sheath did not have a significant impact on development of postoperative hydronephrosis, suggesting ureteral access sheath is safe for use during ureteroscopy. Ureteral strictures remain rare following ureteroscopy, seen in only 1.0% of our cohort. With an observed prevalence of hydronephrosis of 12.0% on followup imaging at 8 weeks, routine upper tract imaging after ureteroscopy remains a valuable prognostic tool.

Evaluation of Patient Factors That Influence Predictive Formulas for Determining Ureteral Stent Length When Compared to Direct Measurement.

Objectives: To compare direct ureteral length measurements with predictive formulas used for the preoperative assessment of ureteral length, and to evaluate patient factors that impact the accuracy of these predictive formulas. Methods: Patients undergoing ureteral stenting for benign and malignant indications were included. Clinical factors analyzed were gender, race, height, weight, prior abdominal or pelvic surgery, radiation therapy, pelvic organ prolapse (POP), laterality, hydronephrosis, and pre-existing ureteral stent. Three predictive formulas and a common height-based formula were used. Direct ureteral measurements were obtained with a ruled 5F ureteral catheter. Predictive formulas were compared with direct ureteral measurements using scatterplot and Spearman's correlation coefficient. Univariate and multivariate logistic regressions were used to evaluate patient factors associated with ≥2 cm deviation from direct ureteral measurements. Results: A total of 108 patients (134 ureters) were analyzed. All predictive formulas correlated poorly with direct ureteral measurements, although as much as 60% of ureteral stent lengths were accurately predicted. Several patient factors significantly impacted accuracy of formulas: male gender (p = 0.04), POP (p = 0.05), body mass index (BMI) ≥25 (p = 0.03), and pre-existing ureteral stent (p = 0.05). Conclusion: Our study suggests that predictive formulas for ureteral stent length have poor accuracy when compared to direct measurement, especially for patients with elevated BMI and POP. Our institution considers direct ureteral measurement the gold standard for determining ureteral stent length-a method that is universally applicable and independent of patient factors.

Long-term Recurrence Rates in Uric Acid Stone Formers With or Without Medical Management.

OBJECTIVE: To determine if medical therapy affects long-term clinical outcomes in uric acid stone formers (UASF). METHODS: We identified 53 UASF who had complete stone clearance following stone procedure by computed tomography (CT) and had ≥1 postoperative 24-hour urine collection and a clinical follow-up ≥6 months with a surveillance CT scan. Patients were divided into "adherent to medical therapy" (compliance with potassium citrate ± allopurinol verified by computerized pharmacy data) or nonadherent groups. Primary outcomes were CT stone recurrence rate and need for surgical stone intervention. RESULTS: We found 28 of 53 (53%) adherent and 25 of 53 (47%) nonadherent individuals (14 declined medication, 11 intolerant). With median follow-up of 24 months, no significant differences were noted between groups in regards to stone recurrence (32%; P = .99) or in 24-hour urine pH compared to baseline or follow-up (range 5.46-5.62; P = 0.06). Adherent patients, however, had smaller CT stone recurrence sizes (6.3 ± 3.8 vs 11.8 ± 6.2 mm, P = .02), were 28% less likely to require stone surgery compared to those without therapy (P <.01), and trended toward longer time intervals without recurrence (23.1 ± 18.8 vs 10.5 ± 7.5 months, P = .10) compared to nonadherents. Study confounders included a variety of medication dosages and adherences, limited nonadherent follow-up, and small study number. CONCLUSION: UASF adherent to medical therapy had smaller recurrence sizes and fewer surgical interventions vs nonadherent, highlighting the protective role of potassium citrate in UA stone disease. The comparable urine pH and stone recurrence rates between groups, however, underscore areas for improvement in future UA stone prevention strategies.

The Urology Applicant: An Analysis of Contemporary Urology Residency Candidates.

OBJECTIVE: To better understand today's urology applicant. METHODS: All 2016 Urology Residency Match applicants to the study-participating institutions were provided a survey via email inquiring about their paths to urology, their career aspirations, how they evaluate a training program, and how they perceive residency programs evaluate them. RESULTS: Of a possible 468 applicants registered for the match, 346 applicants completed the survey. Only 8.7% had a mandatory urology rotation, yet 58.4% believed that a mandatory urology rotation would influence their career decision. Most applicants (62.1%) spent more than 8 weeks on urology rotations, and 79.2% completed 2 or more away rotations. Applicants were attracted to urology by the diversity of procedures, prior exposure to the field, and the mix of medicine and surgery, with mean importance scores of 4.70, 4.52, and 4.45 of 5, respectively. Female applicants were more likely to be interested in pediatric urology, trauma or reconstructive urology, and female pelvic medicine and reconstructive surgery. Significant differences in survey results were noted when applicants were separated by gender. Three-fourths of respondents (75.7%) applied to more than 50 residency programs. Applicants ranked operative experience, interactions with current residents, and relationships between faculty and residents as the most important criteria when evaluating training programs. Of the subspecialties, 62.1% of applicants expressed most interest in urologic oncology. At this stage in their career, a significant majority (83.5%) expressed interest in becoming academic faculty. CONCLUSION: This study provides new information that facilitates a more comprehensive understanding of today's urology applicants.

The Effect of Continued Low Dose Aspirin Therapy in Patients Undergoing Percutaneous Nephrolithotomy.

PURPOSE: Aspirin is often stopped prior to percutaneous nephrolithotomy due to concern about the surgical bleeding risk. There is evidence that discontinuing aspirin perioperatively increases thromboembolic events and continuing it may be safe. We assessed the effect of continuing low dose aspirin through percutaneous nephrolithotomy and its effect on surgical and safety outcomes. MATERIALS AND METHODS: We retrospectively reviewed the records of 285 consecutive percutaneous nephrolithotomies performed between 2012 and 2015 at our institution. We compared outcomes and complications in patients who continued 81 mg aspirin daily to those in patients not receiving aspirin. RESULTS: A total of 67 patients (24.5%) were maintained on low dose aspirin and 207 (75.5%) were not on aspirin. The aspirin group was older (66 vs 52 years), included more tobacco users (58.2% vs 31.4%) and had a higher ASA® (American Society of Anesthesiologists®) score (2.9 vs 2.5, all p <0.001). There was no difference in mean S.T.O.N.E. (size, topography [stone location], obstruction, number of stones and evaluation of HU) score (7.6 vs 7.7, p = 0.71) or blood loss (44 vs 54 ml, p = 0.151). There was no difference in residual stone fragment size, including 0 to 2 mm in 65.3% vs 61.4% of aspirin vs no aspirin cases, 3 to 4 mm in 19.4% vs 16.2% and greater than 4 mm in 15.3% vs 22.4% (p = 0.407). Length of stay and the change in hemoglobin, hematocrit and creatinine were similar. There was no difference in the readmission rate (14.9% vs 12.6%, p = 0.618) or the total complication rate (34.4% vs 26.6%, p = 0.221). There was also no difference in the number of major complications (10.4% vs 5.8%, p = 0.193), bleeding complications (3.0% vs 2.9%, p = 0.971) and the transfusion rate (1.5% vs 1.0%, p = 0.57). CONCLUSIONS: Percutaneous nephrolithotomy appears effective and safe in patients who continue low dose aspirin perioperatively.

Pseudomonas aeruginosa as an Etiologic Agent of Nephrolithiasis in Deep Water Divers.

Background: A number of occupations and professions may be associated with unique hazards relevant to urologic care. Case Presentation: We relate the presentation, care, and the occupational hazard of urinary tract infection (UTI), presenting as cystitis and pyelonephritis, with stone formation in a scuba diver. The patient voiced concern that his diving suit malfunction was related to his UTI and stone disease. We review the risk of UTI in the diving environment. We also report the development of infection-related stone in this case. Our evaluation included consultation with an expert in diving and associated equipment. Conclusion: Careful installation of P-valves in dry suits, proper maintenance, and monitoring for leakage improved post-dive hygiene, and proper maintenance of P-valve tubing and diving equipment may decrease the incidence of these complications described. Urologists treating UTI and stone disease should be aware of this occupation-related hazard.

Multicenter External Validation and Comparison of Stone Scoring Systems in Predicting Outcomes After Percutaneous Nephrolithotomy.

BACKGROUND AND PURPOSE: Several scoring systems have recently emerged to predict stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL). We aimed to compare the most commonly used scoring systems (Guy's stone score, S.T.O.N.E. nephrolithometry, and CROES nomogram), assess their predictive accuracy for SFR and other postoperative variables, and develop a risk group stratification based on these scoring systems. MATERIALS AND METHODS: We performed a retrospective review of patients who have had a PCNL at four academic institutions between 2006 and 2013. Primary outcome was SFR within 3 weeks of the surgery and secondary outcomes were operative time (OT), complications, and length of stay (LOS). We performed chi-squared, t-test, logistic, linear, and Poisson regressions, as well as receiver operating characteristics curve with area under the curve (AUC) calculation. RESULTS: We identified 586 patients eligible for analysis. Of these, 67.4% were stone free. Guy's, S.T.O.N.E., and CROES score were predictive of SFR on multivariable logistic regression (odds ratio [OR]: 1.398, 95% confidence interval [CI]: 1.056, 1.852, p = 0.019; OR: 1.417, 85% CI: 1.231, 1.631, p < 0.001; OR: 0.993, 95% CI: 0.988, 0.998, p = 0.004) and have similar predictive accuracy with AUCs of 0.629, 0.671, and 0.646, respectively. On multivariable linear regression, only S.T.O.N.E. was an independent predictor of longer OT (ß = 14.556, 95% CI: 12.453, 16.660, p < 0.001). None of the scores were independent predictors of postoperative complications or a longer LOS. Poisson regression allowed for risk group stratification and showed the S.T.O.N.E. score and CROES nomogram to have the most distinct risk groups. CONCLUSIONS: The three evaluated scoring systems have similar predictive accuracy of SFR. S.T.O.N.E. has additional value in predicting OT. Risk group stratification can be used for patient counseling. Further research is needed to identify whether or not any is superior to the others with regard to clinical usefulness and predictive accuracy.

Calcium Oxalate Stone Fragment and Crystal Phagocytosis by Human Macrophages.

PURPOSE: In murine and human hyperoxaluric conditions macrophages can be seen surrounding renal calcium oxalate crystal deposits. We hypothesized that macrophages have a role in degrading and destroying these deposits. We investigated the inflammatory response and phagocytic mechanisms when macrophages were exposed to human kidney stones and inorganic crystals. MATERIALS AND METHODS: Human monocytes were differentiated into resting, fully differentiated macrophages by treatment with recombinant human macrophage colony-stimulating factor (M-CSF) or GM-CSF (granulocyte M-CSF) for 6 days. After confirming phenotype by flow cytometry the macrophages were exposed for 20 hours to fragments of sterile human calcium oxalate stones or calcium oxalate crystals. Crystal uptake was determined, and supernatant cytokine and chemokine profiles were analyzed using antibody arrays. Quantitative reverse transcriptase-polymerase chain reaction was done to validate mRNA profile expression. RESULTS: Under direct vision fluorescence microscopy activated human macrophages were noted to surround stone fragments and synthesized crystals, and destroy them in a step-by-step process that involved clathrin mediated endocytosis and phagocytosis. An inflammatory cascade was released by macrophages, including the chemokines chemokine ligand (CCL)2, CCL3, interleukin (IL)-1 receptor antagonist (IL-1ra), complement component C5/C5a and IL-8. Response patterns to stone and crystal material depended on macrophage phenotype and activation status. CONCLUSIONS: In our in vitro study macrophages differentiated with M-CSF showed greater ability to phagocytize crystal deposits than those treated with GM-CSF. Following clathrin mediated endocytosis macrophages released a number of cytokines that are crucial for the inflammatory immune response. This suggests that tissue macrophages have an important role in preventing kidney stone disease by removing and digesting interstitial renal crystal deposits.

Changing Default Fluoroscopy Equipment Settings Decreases Entrance Skin Dose in Patients.

PURPOSE: Proper fluoroscopic education and protocols may reduce the patient radiation dose but few prospective studies in urology have been performed. Using optically stimulated luminescent dosimeters we tested whether fluoroscopy time and/or entrance skin dose would decrease after educational and radiation reduction protocols. MATERIALS AND METHODS: At default manufacturer settings fluoroscopy time and entrance skin dose were prospectively measured using optically stimulated luminescent dosimeters in patients undergoing ureteroscopy, retrograde pyelogram/stent or percutaneous nephrolithotomy with access for stone disease. A validated radiation safety competency test was administered to urology faculty and residents before and after web based, hands-on fluoroscopy training. Default fluoroscopy settings were changed from continuous to intermittent pulse rate and from standard to half-dose output. Fluoroscopy time and entrance skin dose were then measured again. RESULTS: The cohorts of 44 pre-protocol and 50 post-protocol patients with stones were similarly matched. The change in mean fluoroscopy time and entrance skin dose from pre-protocol to post-protocol was -0.6 minutes and -11.6 mGy (33%) for percutaneous nephrolithotomy (p = 0.62 and <0.001), 0.5 minutes and -0.1 mGy (34%) for ureteroscopy (p = 0.42 and 0.31), and 0.1 minute and -0.1 mGy (29%) for retrograde pyelogram/stent (p = 0.85 and 0.49, respectively). Urologist post-training test scores increased 30% from pretraining scores (p = 0.1). CONCLUSIONS: Radiation safety training protocols improved clinical knowledge but did not significantly alter fluoroscopy time. Changing equipment default settings to intermittent pulse rate (12 frames per second) and half-dose lowered the entrance skin dose by 30% across all endourology patients but most significantly during percutaneous nephrolithotomy. To limit patient radiation exposure fluoroscopy default settings should be decreased before all endourology procedures and image equipment manufacturers should consider lowering standard default renal settings.

Clinical, pathologic, and functional outcomes after nephron-sparing surgery in patients with a solitary kidney: a multicenter experience.

BACKGROUND AND PURPOSE: Surgical management of a renal neoplasm in a solitary kidney is a balance between oncologic control and preservation of renal function. We analyzed patients with a renal mass in a solitary kidney undergoing nephron-sparing procedures to determine perioperative, oncologic, and renal functional outcomes. PATIENTS AND METHODS: A multicenter study was performed from 12 institutions. All patients with a functional or anatomic solitary kidney who underwent nephron-sparing surgery for one or more renal masses were included. Tumor size, complications, and recurrence rates were recorded. Renal function was assessed with serum creatinine level and estimated glomerular filtration rate. RESULTS: Ninety-eight patients underwent 105 ablations, and 100 patients underwent partial nephrectomy (PN). Preoperative estimated glomerular filtration rate (eGFR) was similar between the groups. Tumors managed with PN were significantly larger than those managed with ablation (P<0.001). Ablations were associated with a lower overall complication rate (9.5% vs 24%, P=0.01) and higher local recurrence rate (6.7% vs 3%, P=0.04). Eighty-four patients had a preoperative eGFR ≥60 mL/min/1.73 m(2). Among these patients, 19 (23%) fell below this threshold after 3 months and 15 (18%) at 12 months. Postoperatively, there was no significant difference in eGFR between the groups. CONCLUSIONS: Extirpation and ablation are both reasonable options for treatment. Ablation is more minimally invasive, albeit with higher recurrence rates compared with PN. Postoperative renal function is similar in both groups and is not affected by surgical approach.

Impact of body mass index and tumor location on the incidence of benign histology at the time of nephron-sparing surgery.

PURPOSE: Gender, smoking history, patient age, and tumor size have been found to impact the likelihood of benign histology at the time of nephron-sparing surgery (NSS). Providing external validation of these variables and evaluating the relationship between body mass index (BMI) and tumor location on the likelihood of benign histology during NSS for T1 tumors were the objectives of this study. METHODS: Data were analyzed for consecutive patients undergoing NSS for T1 disease. Central tumors either were completely encircled by renal parenchyma, descended below the cortico-medullary junction, or were in direct opposition to the collecting system, renal sinus, or the hilar structures. Categorical variables were evaluated with chi-square test, and continuous variables were analyzed with independent sample t test. Logistic regression identified independent predictors of final pathology. RESULTS: NSS was performed in 316 patients, of whom 79 (24 %) had benign tumors. Patients with benign tumors were more likely to be female, to have a lower BMI, and to have peripheral tumors. On multivariate analysis, female gender (hazard ratio, 3.97; 95 % CI, 2.92-4.53, p < 0.001), peripheral tumor location (hazard ratio, 2.27; 95 % CI, 1.73-3.21, p = 0.014), and lower BMI (hazard ratio, 1.5; 95 % CI, 1.12-1.94, p = 0.015) were independently associated with benign histopathology at the time of surgical resection. CONCLUSIONS: Prospectively identifying which T1 tumors are benign would have tremendous implications for the patient. Ours is the first study that has identified the impact of tumor location and BMI on the risk of benign histology. Additional studies are needed to corroborate these findings and incorporate these data into future nomograms.

Chemokine and chemokine receptor expression in kidney tumors: molecular profiling of histological subtypes and association with metastasis.

PURPOSE: Molecular characterization of renal cell carcinoma may help differentiate benign oncocytoma from malignant renal cell carcinoma subtypes and predict metastasis. Chemokines, eg IL-8 and chemokine receptors such as CXCR4 and 7, promote inflammation and metastasis. SDF-1 is a CXCR4 and 7 ligand with 6 known isoforms. We evaluated the expression of these chemokines and chemokine receptors in kidney specimens. MATERIALS AND METHODS: Using quantitative polymerase chain reaction we measured mRNA levels of IL-8, CXCR4 and 7, and SDF1 isoforms α, ß and γ in a total of 166 specimens from 86 patients, including 86 tumor samples and 80 matched normal kidney samples. Mean ± SD followup was 18.9 ± 12 months (median 19.5). Renal cell carcinoma specimens included the clear cell, papillary and chromophobe subtype in 65, 10 and 5 cases, respectively, and oncocytoma in 6. A total of 17 cases were positive for metastasis. RESULTS: Median CXCR4 and 7, and SFD1-γ levels were increased twofold to tenfold. SDF1-α and ß were unchanged or lower in clear cell renal cell carcinoma and papillary tumors than in normal tissue. Median SDF1-γ, IL-8, and CXCR4 and 7 were increased threefold to fortyfold in chromophobe tumors compared to oncocytoma. CXCR4 and 7 were increased in tumors less than 4 cm (mean 3,057 ± 2,230 and 806 ± 691) compared to oncocytoma (336 ± 325 and 201 ± 281, respectively, p ≤0.016). On multivariate analysis CXCR4 (p = 0.01), CXCR7 (p = 0.02) and SDF1-ß (p = 0.005) were independently associated with metastasis. Combined CXCR7 plus SDF1-α and CXCR7 plus IL-8 markers showed the highest sensitivity (71% to 81%) and specificity (75% to 80%) of all individual or combined markers. CONCLUSIONS: Chemokines and chemokine receptors differentiate renal cell carcinoma and oncocytoma. Combined SDF1-α plus CXCR7 and IL-8 plus CXCR7 markers have about 80% accuracy for predicting renal cell carcinoma metastasis.

Single-center clinical comparison of two reinforced ureteral access sheaths for retrograde ureteroscopic treatment of urinary lithiasis.

BACKGROUND: Ureteral access sheaths (UAS) are used to facilitate ureteroscopic procedures. Difficulties in use, including sheath distortion, buckling, and difficulty in placement, have been reported. However, few clinical comparisons have been performed. We present the first large-scale comparison of the Applied ForteXE(®) and ACMI-Gyrus Uropass(®) UAS. METHODS: We retrospectively compared patients who underwent ureteroscopy for urolithiasis with one of two types of UAS: Applied Forte XE(®) or ACMI-Gyrus Uropass(®). Demographics, operative parameters, and outcomes were assessed. Statistical analysis was performed. RESULTS: In 125 (64.4%) male and 69 (35.6%) female patients, 194 UAS were used. One hundred and thirteen (58.2%) Applied Forte XE(®) and 81 (41.8%) ACMI-Gyrus Uropass(®) were utilized. Success rates for sheath deployment were as follows: overall = 186/194 (95.8%); Applied Forte XE(®) = 107/113 (94.7%); and ACMI-Gyrus Uropass(®) = 79/81 (97.5%) (P = 0.472). Of the 194 patients 131 (67.5%) had a pre-existing stent. Sheath deployment failures occurred in 7 men and 1 woman, of which 4/8 (50%) had no pre-existing stent. Limitations of deployed sheaths occurred at low frequency in both Applied Forte XE 17/107 (15.9%) and ACMI-Gyrus 6/79 (7.6%), with no significant difference observed (P = 0.120). Limitations in use was high in men (P = 0.019). At a mean follow-up of 41 months, no ureteral strictures were noted. CONCLUSIONS: No significant differences were seen in overall success rates for both sheaths. Both sheaths had high deployment success rates and a similar low frequency of sheath-related limitations. We noted increased limitations in the use of deployed sheaths in men. Successful sheath use may depend on both the sheath itself and patient/operative parameters.

Factors that impact the outcome of minimally invasive pyeloplasty: results of the Multi-institutional Laparoscopic and Robotic Pyeloplasty Collaborative Group.

PURPOSE: We compared laparoscopic and robotic pyeloplasty to identify factors associated with procedural efficacy. MATERIALS AND METHODS: We conducted a retrospective multicenter trial incorporating 865 cases from 15 centers. We collected perioperative data including anatomical and procedural factors. Failure was defined subjectively as pain that was unchanged or worse per medical records after surgery. Radiographic failure was defined as unchanged or worsening drainage on renal scans or worsening hydronephrosis on computerized tomography. Bivariate analyses were performed on all outcomes and multivariate analysis was used to assess factors associated with decreased freedom from secondary procedures. RESULTS: Of the cases 759 (274 laparoscopic pyeloplasties with a mean followup of 15 months and 465 robotic pyeloplasties with a mean followup of 11 months, p <0.001) had sufficient data. Laparoscopic pyeloplasty, previous endopyelotomy and intraoperative crossing vessels were associated with decreased freedom from secondary procedures on bivariate analysis, with a 2-year freedom from secondary procedures of 87% for laparoscopic pyeloplasty vs 95% for robotic pyeloplasty, 81% vs 93% for patients with vs without previous endopyelotomy and 88% vs 95% for patients with vs without intraoperative crossing vessels, respectively. However, on multivariate analysis only previous endopyelotomy (HR 4.35) and intraoperative crossing vessels (HR 2.73) significantly impacted freedom from secondary procedures. CONCLUSIONS: Laparoscopic and robotic pyeloplasty are highly effective in treating ureteropelvic junction obstruction. There was no difference in their abilities to render the patient free from secondary procedures on multivariate analysis. Previous endopyelotomy and intraoperative crossing vessels reduced freedom from secondary procedures.

Robot-assisted laparoscopic dismembered pyeloplasty for ureteropelvic junction obstruction: a multi-institutional experience.

OBJECTIVE: To report a 6-year multi-institutional experience and outcomes with robot-assisted laparoscopic pyeloplasty (RLP) for the repair of ureteropelvic junction obstruction (UPJO). PATIENTS AND METHODS: Between June 2002 and October 2008, 168 adult patients from 3 institutions underwent RLP for UPJO. A retrospective analysis of prospectively collected data were performed after institutional review board approval. Diagnosis was by intravenous urogram or computed tomography scan and diuretic renogram. All patients underwent RLP through a 4-port laparoscopic technique. Demographic, preoperative, operative, and postoperative endpoints for primary and secondary repair of UPJO were measured. Success was defined as a T½ of <20 minutes on diuretic renogram and symptom resolution. Pain resolution was assessed by subjective patient reports. RESULTS: Of 168 patients, 147 (87.5%) had primary repairs and 21 (12.5%) had secondary repairs. Of the secondary repairs, 57% had a crossing vessel etiology. Mean operative time was 134.9 minutes, estimated blood loss was 49 mL, and length of stay was 1.5 days. Mean follow-up was 39 months. Overall, 97.6% of patients had a successful outcome, with a 6.6% overall complication rate. CONCLUSIONS: To our knowledge, this review represents the largest multi-institutional experience of RLP with intermediate-term follow-up. RLP is a safe, efficacious, and viable option for either primary or secondary repair of UPJO with reproducible outcomes, a high success rate, and a low incidence of complications.

Molecular characterization of kidney cancer: association of hyaluronic acid family with histological subtypes and metastasis.

BACKGROUND: Molecular profiling of renal cell carcinomas (RCCs) may improve the distinction between oncocytoma and malignant RCC subtypes and aid in early detection of metastasis. The hyaluronic acid (HA) family includes HA synthases (HAS1, HAS2, HAS3), hyaluronidases (HYAL-1, HYAL-2, HYAL-3, HYAL-4, PH20, HYAL-P1), and HA receptors (CD44s, CD44v, RHAMM). HA family members promote tumor growth and metastasis. The authors evaluated the expression of HA family members in kidney specimens. METHODS: By using quantitative polymerase chain reaction, mRNA levels of 12 HA family members were measured in tumor specimens obtained from 86 consecutive patients undergoing nephrectomy; 80 of them also provided normal specimens. Mean and median follow-up were 15.2 ± 8.8 and 13.8 months. RCC specimens included clear cell RCC: 65; papillary: 10; chromophobe: 5; oncocytoma: 6; metastasis positive: 17. RESULTS: Median HAS1, CD44s, and RHAMM transcript levels were elevated 3- to 25-fold in clear cell RCC and papillary and chromophobe tumors when compared with normal tissues. HYAL-4, CD44s, and RHAMM levels were elevated 4- to 12-fold in clear cell RCC and papillary tumors when compared with oncocytomas; only HYAL-4 levels distinguished between chromophobe and oncocytoma (P = .009). CD44s and RHAMM levels were significantly higher in tumors <4 cm (510 ± 611 and 19.6 ± 20.8, respectively) when compared with oncocytoma (46.4 ± 20 and 3.8 ± 2.5; P ≤ .006). In univariate and multivariate analyses, CD44s (P < .0001), RHAMM (P < .0001), stage, tumor size, and/or renal vein involvement were significantly associated with metastasis. The combined CD44s + RHAMM marker had 82% sensitivity and 86% specificity to predict metastasis. CONCLUSIONS: CD44s and RHAMM levels distinguish between oncocytoma and RCC subtypes regardless of tumor size and are potential predictors of RCC metastasis.

Laparoscopic-guided radiofrequency ablation is safe for the treatment of enhancing renal masses among patients prescribed antithrombotic agents.

Patients undergoing laparoscopic-guided radiofrequency ablation (LRFA) for the treatment of a renal mass are commonly prescribed antithrombotic agents for the management of comorbid medical diseases. We retrospectively evaluated the safety of LRFA in this group. From October 2005 to June 2010, 109 patients underwent LRFA. Antithrombotic therapy was prescribed to 52 of these patients. Agents were managed the week of surgery per current practice guidelines from the American College of Chest Physicians. Intraoperatively, patients prescribed at least one antithrombotic agent lost a median of 10 mL of blood, while patients not on an antithrombotic agent also lost 10 mL of blood (P = .828). Both groups had a similar rate of procedure-related complications (intraoperative, P = 1.00; postoperative, P = .673). No patient required a blood transfusion or experienced a postoperative thromboembolic event. In conclusion, when current practice guidelines are followed, LRFA is safe among patients prescribed antithrombotic agents.