Roshan M. Patel

Prone Versus Supine Percutaneous Nephrolithotomy: What Is Your Position?

Purpose of ReviewPercutaneous nephrolithotomy (PCNL) is the gold standard surgical procedure for treating large, complex renal stones. Due to its challenging nature, PCNL has undergone many modifications in surgical technique, instruments, and also in patient positioning. Since the first inception of PCNL, prone position has been traditionally used. However, alternative positions have been proposed and assessed over the years. This is a comprehensive review on the latest developments related to positioning in the practice of PCNL.Recent FindingsThe prone position and its modifications are the most widely used positions for PCNL, but with the introduction of various supine positions, the optimal position has been up for debate. Recent meta-analysis has shown a superior stone-free rate in the prone position and comparable complication rates to the supine position. The advantage of ease of access to the urethra for simultaneous retrograde techniques in the supine position is also possible with modifications in the prone position such as the split-leg technique.SummaryModern-day PCNL has transformed from an operation traditionally undertaken in the prone position to a procedure in which a prone or supine position may be employed; however, published data have not shown significant superiority of either approach.

MP75-14 THE IMPACT OF ONE WEEK OF PRE-OPERATIVE TAMSULOSIN ON DEPLOYMENT OF 16-FRENCH URETERAL ACCESS SHEATHS

quantified by the number of ureteroscope passes through a ureteral access sheath (UAS). METHODS: We prospectively evaluated patients undergoing URS with laser lithotripsy at our institution from December 2015 to October 2016. UAS were used in all patients except those with distal ureteral stones. Every attempt was made to extract all stone fragments, regardless of size, after fragmentation. Patient demographics, stone number, size, and location, and the number of passes of the ureteroscope were recorded. SFR was determined using non-contrast CT scan approximately 8 weeks after the procedure. Stone free (SF) cohort was compared to the residual fragment (RF) cohort using the student0s T-test and the chi-squared test, and binary logistic regression identified factors associated with stone free status. Statistical significance was set at p < 0.05. RESULTS: In total, 104 patients (141 renal units) underwent URS, with 67 patients (84 renal units) completing radiographic follow up to date. Mean number of stones was 3.3 and mean aggregate stone size was 13mm. Our overall SFR was 55%, with a mean number of ureteroscope passes of 44 (range 1 164). On univariate comparison between the SF and RF cohorts, SF patients had fewer numbers of stones (2.4 vs. 4.3, p1⁄40.001), smaller aggregate stone size (11 vs. 15mm, p1⁄40.02), and a smaller proportion of renal or renal and ureteral stones (54% and 15% vs. 66% and 26%, respectively, p1⁄40.003). There were no significant differences in OR time, UAS size, or the number of ureteroscope passes (41 vs. 48, p1⁄40.4) between groups. Binary logistic regression revealed no significant factors predictive of SF status. CONCLUSIONS: SFRs by CT after URS are disappointingly low even with aggressive manual fragment retrieval. Larger sample size is likely to identify select cohorts of patients that benefit most from URS.

Multi-institutional Evaluation of Upper Urinary Tract Biopsy Using Backloaded Cup Biopsy Forceps, a Nitinol Basket, and Standard Cup Biopsy Forceps

OBJECTIVE To compare the performance of 3 contemporary ureteroscopic biopsy devices for the histopathologic diagnosis of upper tract urothelial carcinoma (UTUC). METHODS We retrospectively reviewed 145 patients who underwent 182 urothelial biopsies using 2.4F backloaded cup biopsy forceps, a nitinol basket, or 3F standard cup biopsy forceps at 3 tertiary academic centers between 2011 and 2016. Experienced genitourinary pathologists provided an assessment of each specimen without knowledge of the device used for biopsy. For patients who underwent nephroureterectomy without neoadjuvant chemotherapy within 3 months of biopsy-proven UTUC diagnosis, the biopsy grade was compared with both the grade and stage of the surgical specimen. RESULTS Biopsy utilization varied among the 3 institutions (P <.0001). Significant variabilities in specimen size (P = .001), the presence of intact urothelium (P = .008), and crush artifact (P = .028) were found among the biopsy devices. The quality of specimens from backloaded cup forceps was rated similarly to the nitinol basket (P >.05) and was favored over standard cup forceps specimens. Grade concordance was not affected by specimen size (P >.05), morphology (P >.1), or location (P >.5). No difference existed among the devices in the rate of acquiring a grade concordant biopsy; however, the backloaded cup forceps provided concordant biopsies that could be distinguished as low- and high-grade (P = .02). CONCLUSION The backloaded cup forceps and nitinol basket obtained a higher quality urothelial specimen compared with standard cup forceps. Ureteroscopic biopsy device selection did not significantly impact the accuracy of the histologic diagnosis of UTUC.

MP24-15 SURFACE-TREATED PELLETHANE: COMPARATIVE QUANTIFICATION OF ENCRUSTATION IN ARTIFICIAL URINE SOLUTION

INTRODUCTION AND OBJECTIVES: Pellethane is an aromatic polyether-based thermoplastic polyurethane noted for its strength, flexibility, and resistance to solvents. No studies have assessed the encrustation properties of Pellethane and surface-treated Pellethanes in urine. In an effort to identify a better material for ureteral stents, we sought to assess the stability in artificial urine (AU) (Ward0s Science ) of uncoated Pellethane and Pellethane surface-grafted with either 2hydroxyethyl methacrylate (HEMA), a hydrogel, or tetraethylene glycol dimethyl ether (tetraglyme), both of which have the ability to resist protein adsorption. METHODS: In a batch-flow AU model (Figure 1), Pellethane, HEMA-grafted Pellethane, and tetraglyme-grafted Pellethane, were tested against a commercially available hydrogel-coated latex urinary catheter (Bard ) and a hydrophilic polymer-coated polyurethane ureteral stent (Cook Medical ). Encrustation was quantified by the change in dry weight. Cylindrical samples of comparable mass were weighed prior to suspension in AU; 3-day, 7-day, and 30-day immersion trials were conducted. AU solution refresh was done on alternating days. Samples were dried for 48 hours in a fume hood prior to being weighed. RESULTS: Pellethane products exhibited less mass increase than the commercially available catheter or stent (Table 1). At the conclusion of the 30-day trial, the mass changes were: catheter, +6.40%; stent, +8.63%; uncoated Pellethane, +0.58%; HEMA-grafted Pellethane, +0.07%; and tetraglyme-grafted Pellethane, -0.76%. The tetraglyme-coated Pellethane may have lost mass due to extraction of components from the tetraglyme coating in AUS. CONCLUSIONS: Compared to commercially available urinary catheters and ureteral stents, Pellethane with and without surfacetreatment with HEMA or tetraglyme reduces encrustation in an artificial urine model. Source of Funding: none

Quarter Century Management of Chronic Ureteropelvic Junction Obstruction in a Solitary Kidney with a Ureteral Stent.

Abstract Background: The ureteral stent provides a conduit for urinary drainage from the kidney to the bladder and is integral to contemporary urologic practice. A ureteral stent is often utilized in acute conditions to prevent or overcome obstruction; however, in nonsurgical patients, because of disease or preference, a ureteral stent may be used as a last resort for long-term management of a stricture in lieu of a nephrostomy tube. This case highlights a patient whose chronic ureteral obstruction has been managed with an indwelling ureteral stent for 25 years; remarkably, stent exchanges are currently required only every 2 years. Case Presentation: A 33-year-old man initially presented with a solitary left kidney and a ureteropelvic junction obstruction. The patients right kidney was nonfunctioning since childhood because of a presumed ureteropelvic junction obstruction with grade IV hydronephrosis. The patient underwent two failed open repairs of the left kidney in the 1980s, resulting in a totally intrarenal, constricted renal pelvis; an endopyelotomy in 1992 also failed and required angioembolizaton of a segmental renal vessel. The patient refused any further surgical procedures and thus has been managed exclusively with a 7/14F × 28 cm endopyelotomy stent (Boston Scientific®) for 25 years; the interval between stent changes was slowly expanded until they are now being done at 2-year intervals. The patient has not developed recurrent urinary tract infections, stent colic, or stent encrustation. Conclusion: Patients who require chronic indwelling ureteral stents are rare. In this situation, with careful monitoring, the interval between stent exchanges was extended to 2 years, thereby precluding a chronic nephrostomy tube.

“STONE TREES”: Metabolic Evaluation and Medical Treatment of the Urolithiasis Patient Made Easy

In this review, a simplified straightforward algorithmic approach to the metabolic evaluation and treatment of the at-risk or recurrent urolithiasis patient is provided. Eight diagnoses and eight therapies are provided, which cover over 95% of renal stone disease.

The Endockscope Using Next Generation Smartphones: “A Global Opportunity”

INTRODUCTION The Endockscope combines a smartphone, a battery powered flashlight and a fiberoptic cystoscope allowing for mobile videocystoscopy. We compared conventional videocystoscopy with the Endockscope paired with next generation smartphones in an ex-vivo porcine bladder to evaluate its image quality. MATERIALS AND METHODS The Endockscope consists of a three-dimensional (3D) printed attachment that connects a smartphone to a flexible fiberoptic cystoscope plus a 1000 lumen light-emitting diode (LED) cordless light source. Video recordings of porcine cystoscopy with a fiberoptic flexible cystoscope (Storz) were captured for each mobile device (iPhone 6, iPhone 6S, iPhone 7, Samsung S8, and Google Pixel) and for the high-definition (HD) H3-Z versatile camera setup with both the LED light source and the xenon light (XL) source. Eleven faculty urologists, blinded to the modality used, evaluated each video for image quality/resolution, brightness, color quality, sharpness, overall quality, and acceptability for diagnostic use. RESULTS When comparing the Endockscope coupled to a Galaxy S8, iPhone 7, and iPhone 6S with the LED portable light source to the HD camera with XL, there were no statistically significant differences (p < 0.01) in any metric. Eighty-two percent and 55% of evaluators considered the iPhone 7 + LED light source and iPhone 6S + LED light, respectively, appropriate for diagnostic purposes as compared with 100% who considered both the HD camera with XL and Galaxy S8 + LED appropriate. The iPhone 6 and Google Pixel coupled with the LED source were both inferior to the HD camera with XL in all metrics. CONCLUSIONS The Endockscope system with a LED light source (

The Effect of Positioning on Ureteral Stone Retropulsion: “Gravity Works”

45) when coupled with either an Apple iPhone 7 or Samsung Galaxy S8 is comparable to conventional videocystoscopy with a standard camera and XL light source (total cost:

MP100-03 MULTI-POINT THERMAL SENSING NEEDLES: IMPROVED ONCOLOGICAL OUTCOMES FOLLOWING CRYOABLATION

45,000).

PD42-09 CLINICAL COMPARISON OF CONVENTIONAL AND MOBILE ENDOCKSCOPE VIDEOCYSTOSCOPY USING AN AIR OR FLUID IRRIGANT

To evaluate the potential impact of alterations in ‘patient’ position on laser‐induced ureteric stone retropulsion in an in vitro model.