Benchtop Evaluation of Miniature Percutaneous Nephrolithotomy Lithotrites.

Introduction: Percutaneous nephrolithotomy (PCNL) is the preferred treatment for kidney stones >2 cm. While PCNL has traditionally been performed using 24F to 30F access sheaths, there is a trend toward smaller sheaths and scopes to perform mini-PCNL (mPCNL). We performed benchtop assessment of multiple mPCNL lithotrites. Methods: One 1 cm3, hard Begostone phantom was placed in a cylinder with four 5.5 mm cylindrical openings to simulate the size of a 16.5F mPCNL sheath. Lithotripsy was performed with the 1.5 and 1.9 mm Trilogy, 1.83 mm ShockPulse, or a 200 µm Holmium:YAG (Ho:YAG) laser. Suction was used for the mechanical lithotrites. The Trilogy probes were set at 50% impact, 6 Hz, 80% ultrasound and 10% suction. The ShockPulse was used at high-power setting with low suction. The 1.9 mm Trilogy probe was used with a 15F mini-nephroscope. The 1.83 mm ShockPulse, 1.5 mm Trilogy and laser fiber were used with a 12F mini-nephroscope. The 120 W holmium laser was set at 0.5 J/70 Hz Moses-Distance. Ten independent runs were performed with modality. Time to complete stone clearance was recorded and mass stone clearance rates were calculated. Results: The Trilogy 1.9 mm showed superior stone clearance rate (11.69 ± 3.68 mg/s) vs the ShockPulse (SP) 1.83 mm (6.29 ± 1.37 mg/s, p = 0.003), the laser fiber (4.73 ± 0.61 mg/s, p < 0.0005), and the Trilogy 1.5 mm (6.84 ± 1.21 mg/s). The 200 µm laser fiber was inferior to all mechanical lithotrites. There was no difference between the 1.5 mm Trilogy and the 1.83 mm ShockPulse (p = 0.772). This translates to 3.9, 4.8, and 8.1 minutes less treatment time vs the 1.5 mm Trilogy, SP, and laser, respectively, for a spherical 1.5 cm diameter calcium oxalate monohydrate stone. Conclusion: Among these four commonly used mPCNL lithotripters, the Trilogy 1.9 mm demonstrated superior stone clearance rates in this benchtop model vs the Ho:YAG laser, 1.83 mm SP, and Trilogy 1.5 mm. Future clinical testing is warranted to evaluate the optimal lithotrite for mPCNL.

Investigating Risk Factors for Urine Culture Contamination in Outpatient Clinics: A New Avenue for Diagnostic Stewardship.

Mixed flora in urine cultures usually occur due to pre-analytic contamination. In our outpatient urology clinic, we found a high prevalence of mixed flora (46.2%), which was associated with female sex and older age. Patient education did not impact the rate of mixed flora. Future efforts should target high-risk patients.

Evolution of Single-Use Urologic Endoscopy: Benchtop and Initial Clinical Assessment of a New Single-Use Flexible Cystoscope.

Introduction: Office cystoscopy is one of the most frequently performed procedures by a urologist. However, single-use cystoscopes remain quite undeveloped. Ambu® has developed single-use broncoscopes, rhinolaryngoscopes, and duodenoscopes. Recently, they released a single-use cystoscope. In this study, we performed a benchtop and an initial clinical assessment of the Ambu aScope™ (4) Cysto (aS4C) single-use cystoscope. Materials and Methods: Ten new, never-used aS4C single-use cystoscopes were assessed for optical performance, maximal tip flexion, and irrigation flow rate with empty working channel, 365 µm laser fiber, 0.035 in hydrophilic-tipped wire, 1.9F nitinol basket, and a 1.8 mm flexible stent grasper. All cystoscopes were then fully flexed 25 times in each direction, and maximal flexion angles were remeasured with and without instruments. Optical resolution, distortion, and depth of field were measured and compared with our reusable digital flexible cystoscopes. Assessment of clinical use was performed for inpatient bedside procedures using a Likert feedback survey and the NASA Task Load Index. Results: Maximal upward flexion exceeded 200° and 160° for all working instruments in upward and downward flexion. Downward flexion demonstrated different flexion between instrument groups in pre- and postcycling (p < 0.001). There was no clinical difference between the pre- and postcycling flexion. Flow rate decreased with increasing working instrument size (p < 0.001). The Olympus HD cystoscope resolution was superior at 3 and 5 mm distance, but not at other distances. The Ambu scope was superior to the Olympus SD scope at all distances except 3 mm. The aS4C had higher Likert scale survey scores for clinical use. Conclusions: The new Ambu single-use cystoscope demonstrates good flexion across instruments and comparable optics with reusable cystoscopes. In addition, initial inpatient bedside use of the aS4C and Monitor system compares favorably with the Olympus reusable cystoscope. Further testing in clinical scenarios such as hematuria, urothelial carcinoma, and operative endoscopy is warranted.

Novel Irrigation Protocol for Renal Pelvis Sterilization During Percutaneous Nephrolithotomy: A Pilot Study.

While percutaneous nephrolithotomy (PCNL) remains the treatment modality of choice for kidney stones larger than 2 cm, infectious complications are most common, ranging from 5% to 32%. We present here a novel technique for potentially improving collecting system sterility during PCNL and initial postoperative outcomes. Retrospective chart analysis data of our irrigation protocol were collected from our first 56 patients between February and July 2019. Traditional prone PCNL was performed in a standard manner using fluoroscopic guidance. Using a ureteral catheter that was placed cystoscopically, a renal pelvis urine culture was taken and subsequently 10 mL of betadine solution was instilled into the collecting system. Gentamicin in normal saline (80 mg/3 L) was utilized as the irrigant fluid for the first 6 L of irrigation. From this cohort, 57% patients were women and mean age was 60 ± 14 years. About 23% of patients were diabetic and 55% were hypertensive. Seventy percent of patients had stone burden >2 cm and no patients had stone burden <1 cm. Fifteen patients had positive urine cultures treated preoperatively, while four patients had contaminated cultures. All patients were treated with our antibiotic irrigation and betadine protocol regardless of preoperative cultures or antibiotics. Mean baseline creatinine level was 0.95 ± 0.41, with a mean change of 0.18 at postoperative day 1. Of the 15 (26%) of 56 patients with a systemic inflammatory response syndrome response (two of following four criteria: white blood cells <4 or >12; heart rate >90; hypothermia <96.8°F or hyperthermia >100.4°F; and respiratory rate >20), only six patients (11%) were febrile and two patients had positive blood cultures (3%). There were no adverse reactions to the betadine or antibiotic irrigation. We present here our initial experience of a new technique for renal pelvis sterilization and its safety and feasibility using intrarenal instillation of betadine and antibiotic irrigation. No Clinical Trial Registration number applicable.

Management and treatment options when facing malignant ureteral obstruction.

Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide-ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first-line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra-anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: "malignant ureteral obstruction," "tandem ureteral stents," "metallic ureteral stents," "resonance stent," "metal mesh ureteral stents" and "extra-anatomic stents." The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head-to-head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case-by-case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence-based medicine and guidelines for patients with malignant ureteral obstruction.

Massive Neobladder Stones in Postcystectomy Patient Lost to Follow Up.

A 59-year-old man with a history of muscle-invasive bladder cancer status post cystectomy with neobladder creation presented to the Emergency Department with a 4-month history of lower abdominal pain, dysuria, and intermittent hematuria. He was found to have 2 massive bladder stones on CT scan, measuring 12 × 10.5 × 14 cm and 6.5 × 7.5 × 10 cm. Stones were successfully removed via open neocystolithotomy. Stones were composed of a mixture of calcium phosphate (80%) and calcium carbonate (20%).

Efficacy of Multi-Detector Computed Tomography for the Diagnosis of Medullary Sponge Kidney.

OBJECTIVE: To expand the diagnostic armamentarium for medullary sponge kidney (MSK), we evaluate the use of high-resolution multidetector computed tomography (MDCT) for MSK diagnosis and compare to the standard intravenous urography (IVU). Despite a significant prevalence amongst stone formers, diagnosis of this well described condition has declined. IVU, the gold standard in MSK diagnosis, has largely been replaced by CT, which has previously been shown unable to demonstrate signs of MSK. METHODS AND MATERIALS: Patients with known history of MSK based on IVU underwent limited MDCT urogram. Control group patients, without MSK, also had MDCT urograms performed for other clinically indicated conditions. Studies were scored by board-certified radiologists on a 0-2 scale based on the likelihood of MSK. IVU studies, when available, were similarly graded. RESULTS: MDCT was diagnostic of MSK in 9 out of the 10 patients with known history of MSK. No false positives were present in our series. The one case of MSK not detected on MDCT was graded as a "1" on its respective IVU. Sensitivity and specificity were 90 and 100%, respectively, when compared with IVU. CONCLUSION: Concordance with IVU findings, despite a small reduction in sensitivity, indicates MDCT to be a suitable, and more readily available replacement for IVU in the diagnosis of MSK.

Differentiating reconstructive techniques in partial nephrectomy: a propensity score analysis.

INTRODUCTION: To assess whether volumetric measurements can differentiate functional changes between reconstructive techniques after partial nephrectomy. MATERIALS AND METHODS: One hundred and fifty-six patients undergoing partial nephrectomy for a single renal mass were retrospectively studied between 2008 and 2012. Computed tomography scans were available for volume calculations on 56 (18 non-renorrhaphy and 38 renorrhaphy). Institutional review board approval was obtained. The primary outcome was %volume loss in the operated kidney, which was calculated from three-dimensional reconstructions using a semiautomatic segmentation algorithm. Multivariable regression and propensity score analysis was performed. RESULTS: Volumetric analysis detected a difference in mean %volume loss between two-layer reconstruction (cortical renorrhaphy and base-layer) and base-layer only (15.6% versus 3.8%, p < 0.001). The mean %glomerular filtration rate (GFR) loss was also greater in the two-layer group (8.9% versus 2.4%, p = 0.03). Demographics were similar between groups except the two-layer group was older, had more males, and increased ischemia time. On multivariable regression the presence of two-layer closure (ß = -15.2%, p < 0.001) and tumor diameter (ß = -7.4, p = 0.004) were significant predictors of %volume loss while ischemia time (p = 0.88) was not. Two-layer closure remained a predictor on propensity-adjusted analysis (ß = -14.3, p = 0.004). The base-layer only group had two (5.3%) urine leaks and two (5.3%) bleeding complications. The two-layer group had two (1.7%) urine leaks and three (2.5%) bleeding complications (p = 0.23, 0.41). CONCLUSIONS: Volume loss calculated from CT scans can be used to monitor postoperative renal function. Techniques for renal reconstruction and tumor diameter are associated with volume and functional loss after partial nephrectomy and should be controlled for in future studies.

Reducing Operating Room Costs Through Real-Time Cost Information Feedback: A Pilot Study.

PURPOSE: To create a protocol for providing real-time operating room (OR) cost feedback to surgeons. We hypothesize that this protocol will reduce costs in a responsible way without sacrificing quality of care. METHODS: All OR costs were obtained and recorded for robot-assisted partial nephrectomy and laparoscopic donor nephrectomy. Before the beginning of this project, costs pertaining to the 20 most recent cases were analyzed. Items were identified from previous cases as modifiable for replacement or omission. Timely feedback of total OR costs and cost of each item used was provided to the surgeon after each case, and costs were analyzed. RESULTS: A cost analysis of the robot-assisted partial nephrectomy before the washout period indicates expenditures of $5243.04 per case. Ten recommended modifiable items were found to have an average per case cost of $1229.33 representing 23.4% of the total cost. A postwashout period cost analysis found the total OR cost decreased by $899.67 (17.2%) because of changes directly related to the modifiable items. Therefore, 73.2% of the possible identified savings was realized. The same stepwise approach was applied to laparoscopic donor nephrectomies. The average total cost per case before the washout period was $3530.05 with $457.54 attributed to modifiable items. After the washout period, modifiable items costs were reduced by $289.73 (8.0%). No complications occurred in the donor nephrectomy cases while one postoperative complication occurred in the partial nephrectomy group. CONCLUSION: Providing surgeons with feedback related to OR costs may lead to a change in surgeon behavior and decreased overall costs. Further studies are needed to show equivalence in patient outcomes.

Synchronous perivesical and renal malignant rhabdoid tumor in a 9-year-old boy: a case report and review of literature.

Pediatric extrarenal malignant rhabdoid tumors (MRTs) are rare and aggressive (20% 5-year survival). Only 2 cases of bladder MRTs have been published. We report on a 9-year-old boy presenting with gross hematuria, palpable pelvic mass, and an obstructed, nonfunctional kidney. Evaluation was consistent with a 9.7 cm extrarenal MRT invading the bladder and prostate. He underwent a cystoprostatectomy, Indiana pouch continent urinary reservoir creation, and a left nephroureterectomy. A discrete 2.5 cm focus of renal MRT was found. To our knowledge, this is the first case of simultaneous perivesical and renal MRT. We review the current management of pediatric extrarenal MRTs.