Surface-Treated Pellethanes: Comparative Quantification of Encrustation in Artificial Urine Solution.

Introduction: Encrustation of implanted urinary tract devices is associated with significant morbidity. Pellethane® is a polyether-based compound noted for its strength, porosity, and resistance to solvents. We assessed Pellethane thermoplastic polyurethane (TPU) with and without surface coatings 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethyl ether (TETRA) for the potential to resist encrustation in an artificial urine environment. Materials and Methods: Samples of Pellethane TPU, HEMA Pellethane TPU, TETRA Pellethane TPU, and hydrogel-coated ureteral stent (Cook®) were suspended in a batch-flow model with an artificial urine solution (AUS). Every 48 hours for 90 days, 40% of the solution was replaced with fresh AUS. All samples were stored in a 37°C incubator. Subsequently, the samples were thoroughly dried for 48 hours before weighing. Scanning electron microscopy was used to assess the degree of encrustation. Nu-Attom Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the precise compositions of the encrustation specifically with regard to calcium, magnesium, and phosphate. Results: At the conclusion of the 90-day trial, the samples were analyzed, and the average mass changes were as follows: stent 63.78%, uncoated Pellethane TPU 11.50%, HEMA-coated Pellethane TPU 2.90%, and TETRA-coated Pellethane TPU 0.60%. Pellethane TPU products, and specifically those coated with HEMA and TETRA, exhibited less average mass increase and a lesser propensity to form encrustation than the traditional urinary tract stent. The mass increases noted on coated Pellethane devices were primarily ionic, whereas that of the stent was not. Conclusion: Pellethane, particularly with an HEMA-based preventative coating, may serve as a favorable alternative to traditional urinary stent material, providing its improved resistance to encrustation.

Prospective Randomized Comparison of Standard Hand Pump Infuser Irrigation vs an Automated Irrigation Pump During Percutaneous Nephrolithotomy and Ureteroscopy: Assessment of Operating Room Efficiency and Surgeon Satisfaction.

Introduction: The objective of this study was to determine if use of an automated irrigation pump (AIP) during ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) affects circulating nurse labor, irrigation-related issues, and surgeon and nurse satisfaction when compared to manual hand pump (HP) irrigation. Methods: Eighty consecutive adult patients undergoing unilateral URS or PCNL were prospectively randomized to irrigation with the HP or AIP. Preoperative pump setup time, intraoperative pump maintenance time, total pump time (setup+maintenance), and the number of irrigation-related concerns verbalized by the surgeon intraoperatively were recorded; postoperatively, surgeons and nurses rated their satisfaction with the irrigation system (1 = highly dissatisfied to 10 = highly satisfied). Results: Eighty patients were enrolled (39 AIP and 41 HP); 51 patients underwent URS and 29 patients underwent PCNL. On univariate analysis, the AIP resulted in a significantly reduced total pump time for URS (2.9 vs 5.9 minutes) and PCNL (4.6 vs 33.9 minutes; p < 0.001). The number of irrigation-related concerns was significantly lower in the AIP group during URS (1.2 vs 2.8, p < 0.001), but not during PCNL (1.9 vs 4.0, p = 0.07). The AIP was associated with significantly higher nurse satisfaction during URS (9.2/10 vs 6.5/10, p < 0.001) and PCNL (9.4/10 vs 4.4/10, p = 0.001). There was no significant association between pump type and surgeon satisfaction. On multivariate analysis of URS cases controlling for body mass index and number of stones, use of the AIP was a predictor of total pump time <5 minutes (odds ratio 25.8, 95% confidence interval [CI] 4.0-165.4; p < 0.001) and favorable (8-10/10) nurse satisfaction rating (odds ratio 25.4, 95% CI 4.1-164.0; p < 0.001). Operative time, stone-free rate, and liters of irrigant used with the HP and AIP were similar. Conclusions: During URS and PCNL, the AIP was associated with a significant reduction in irrigation pump time and higher nurse satisfaction.

Reducing kidney motion: optimizing anesthesia and combining respiratory support for retrograde intrarenal surgery: a pilot study.

BACKGROUND: One of the greatest challenges presented with RIRS is the potential for movement of the stone within the operative field associated with diaphragm and chest respiratory excursions due to mechanical ventilation. To overcome this challenge, we propose in this pilot study a new general anesthesia technique combining high frequency jet ventilation (HFJV) with small volume mechanical ventilation (SVMV). Data regarding safety, feasibility and surgeons' impression was assessed. METHODS: Patients undergoing RIRS for kidney stones from November 2017 to May 2018 were prospectively recruited to participate in the study. In each case after the beginning of general anesthesia (GA) with mechanical ventilation (MV) surgeons were asked to assess the mobility of the operative field and conditions for laser lithotripsy according to the developed questionnaire scale. The questionnaire consisted of 5 degrees of assessment of kidney mobility and each question was scored from 1 to 5, 1 being very mobile (extremely poor conditions for dusting) and 5 completely immobile (Ideal conditions for dusting). After the assessment GA was modified with combined respiratory support (CRS), reducing tidal volume and respiratory rate (small volume mechanical ventilation, SVMV) and applying in the same time transcatheter high frequency jet ventilation (HFJV) inside the closed circuit. After beginning of CRS, surgeons were once again asked to assess the mobility of the operative field and the conditions for laser lithotripsy. Main ventilation parameters were recorded and compared in both regimens. RESULTS: A total of 38 patients were included in the study. The mean age was 49 (range 45-53) with a mean stone size of 10 mm (range 10-14) and Hounsfield unit of 1060 (range 930-1190). All patients underwent successful RIRS and no intraoperative complications occurred throughout the duration of the study. A statistically significant difference between ventilation parameters prior to and after CRS institution was detected in all cases, however their clinical impact was negligible. Despite this, assessment via the questionnaire scale point values varied significantly before and after the application of CRS and were 2.3 (2.1; 2.6) and 3.8 (3.7; 4.0) respectively (p < 0.001). CONCLUSIONS: The novel combined respiratory approach consisting of HFJV and SVMV appears to provide better conditions for stone dusting through reduced respiratory kidney motion and is not associated with adverse health effects or complications. TRIAL REGISTRATION: NCT03999255 , date of registration: 25th June 2019 (retrospectively registered).

Endockscope: A Disruptive Endoscopic Technology.

Objective: To assess optical performance and diagnostic capability of the Endockscope system (ES) vs the standard endoscopic system (SES) using four rigid/semi-rigid endoscopes. The ES combines a smartphone, lens system, and a rechargeable light-emitting diode (LED) light source to provide a low-cost alternative ($45) to the standard camera and high-powered light source ($45,000) used in endoscopic procedures. Materials and Methods: Video clips (<20 seconds) of standard rigid nephroscopy, semi-rigid ureteroscopy, rigid cystoscopy, and laparoscopy in two adult male cadavers were recorded using the ES combined with either the Apple iPhone X or Samsung Galaxy S9+ and also with the high-definition SES (Karl Storz). Sixteen urologists blinded to the camera modality assessed the image resolution, brightness, color, sharpness, and overall quality using a Likert-type scale; acceptability for diagnostic purposes was judged on a binary scale (yes/no). Results: For rigid cystoscopy, there was no statistical difference between both ES systems and the SES. For semi-rigid ureteroscopy the two ES systems performed equal to or better than the SES. For rigid nephroscopy, the ES plus Galaxy was comparable to the SES, except in brightness (p < 0.05), whereas the ES plus iPhone was inferior in various parameters. For laparoscopy, the ES plus Galaxy was inferior to the SES in brightness and overall quality (p < 0.05); the ES plus iPhone was inferior for all laparoscopic image parameters compared with the SES. For diagnostic purposes, the ES plus Galaxy was equivalent to the SES for all endoscopes; the ES plus iPhone was equivalent to the SES for cystoscopy, ureteroscopy, and nephroscopy. Conclusion: The ES plus the Apple iPhone X or Samsung Galaxy S9+ offers comparable imaging and provides diagnostic information equivalent to the standard system for rigid endoscopy of the kidney, ureter, and bladder; the Galaxy S9+ provides comparable imaging and diagnostic capabilities for evaluation of the abdomen.