Patrick Yang

Do Illuminated Foot Pedals Improve the Speed and Accuracy of Pedal Activation During Endoscopic Procedures

PURPOSE Endourologic procedures such as percutaneous nephrolithotomy (PCNL) employ the use of foot pedals in low-light operating room (OR) settings. These pedals can be especially difficult to locate or distinguish when several pedals are present during a single operation. Improper instrument activation in the OR has led to serious complications ranging from unintentional electrocautery to patient burns and even an intraoperative explosion. This study evaluates the impact of color-coded illumination on speed and efficiency of foot pedal activation. MATERIALS AND METHODS During a simulated PCNL procedure, the foot pedals for a C-arm, laser, and ultrasonic lithotripter (USL) were placed in random positions. Ten participants performed pedal activation in a randomized sequence. Objective outcomes included time to instrument activation, number of attempted pedal presses, number of incomplete pedal presses, and number of incorrect pedal presses. Subjective preferences for pedal illumination were also determined. Data were analyzed using Mann-Whitney U, Wilcoxon signed-rank, and Chi-square tests with p < 0.05 indicating statistical significance. RESULTS Illuminated foot pedals were associated with decreases in the average activation time for all instruments collectively (3.95 seconds vs 6.49 seconds; p = 0.017) and individually (C-arm: 3.07 seconds vs 4.21 seconds; p = 0.006; laser: 13.04 seconds vs 15.18 seconds; p < 0.001; USL: 3.28 seconds vs 4.91 seconds; p < 0.001) compared with nonilluminated pedals. Illuminated pedals were associated with fewer attempted pedal presses (33.5 vs 39.5; p = 0.007) and incomplete pedal presses (1.5 vs 8.5; p = 0.002). The number of incorrect pedal presses decreased with illumination, but this did not reach statistical significance (0 vs 0.5; p = 0.08). Participants reported that illumination simplified pedal activation and recommended its use (p < 0.01). CONCLUSION Color-coded illumination improved the speed and efficiency of foot pedal activation during simulated PCNL. Participants subjectively preferred using illuminated foot pedals for endourologic procedures and felt that they improved safety and efficiency.

MP59-17 SUBCLINICAL RHABDOMYOLYSIS: AN UNDER-RECOGNIZED CONTRIBUTOR TO POSTOPERATIVE ACUTE KIDNEY INJURY IN PATIENTS UNDERGOING MINIMALLY INVASIVE UROLOGIC SURGERY

model (Spearman rho of 0.779) demonstrating preoperative GFR and GFR loss at 6 weeks post-op as the most important predictive factors. 10-year overall risk of NRCM was 29%. Significant predictors of NRCM were preoperative GFR, new baseline GFR, age, diabetes, and hypertension (all p<0.05). A predictive nomogram for 10-year NRCM was created with a c-index 0.71, demonstrating age and preoperative GFR as the most important predictive factors. GFR loss with surgery, as would be seen with typical PN vs. RN, only changed absolute mortality risk by 1-3% in nomogram-based examples (see Figure). CONCLUSIONS: GFR loss with RCS, which is directly related to choice of PN vs RN, strongly influences risk of developing CKD, but has much less impact on long-term survival. In contrast, age and preoperative GFR are much more robust predictors of 10year NRCM.

PD21-04 COMPARISON OF ULTRASOUND-GUIDED, CONVENTIONAL FLUOROSCOPIC, AND A NOVEL LASER DIRECT ALIGNMENT RADIATION REDUCTION TECHNIQUE FOR PERCUTANEOUS NEPHROLITHOTOMY

There was no association between patient0s CCI, age, race, insurance, hospital location (urban vs non-urban, and hospital type (teaching vs non-teaching) with regard to physician specialty obtaining RA. On multivariable analysis, RA by urologist was associated with lower rates of any complication (Clavien 1-5), shorter hospitalization (<2 days) and lower direct admission costs (<

V7-06 PERCUTANEOUS EXTERNALLY ASSEMBLED LAPAROSCOPIC (PEAL) SURGERY FOR FOWLER-STEPHENS ORCHIOPEXY: A VIDEO PRESENTATION

12,515) Figure 1. CONCLUSIONS: PCNL is performed with urologists obtaining percutaneous access the minority of the time in the United States. Highvolume urologists are more likely to obtain their own access. Access by urologist is associated with lower overall complications, shorter hospitalizations, and lower direct hospital costs.

MP66-12 PERCUTANEOUS EXTERNALLY ASSEMBLED LAPAROSCOPIC INSTRUMENTS FOR FOWLER-STEPHENS ORCHIOPEXY: THE FEASIBILITY OF A NEW SURGICAL SYSTEM

METHODS: A collaborative team was formed and consisted of a pediatric urologist trained in minimally invasive and oncologic surgery as primary surgeon with an adult minimally invasive oncologic urologist as proctor. Key aspects for translation to the pediatric setting included: port placement, lower insufflation pressure, choice and size of instruments and supplies, and minimization of potential hemorrhage and ischemia with selective clamping/early unclamping technique. This approach was applied to a 14 kilogram, 3 year old female with a right lower pole lesion with cystic and solid components, concerning for malignancy. RESULTS: The mass was resected with negative margins and demonstrated benign pathology. Clamp time was 14 minutes, and EBL was minimal. There were no intraor post-operative complications. The patient’s creatinine was unchanged, and a follow-up ultrasound demonstrated no residual mass in a normal appearing right kidney. CONCLUSIONS: Collaboration of experienced pediatric and robotic teams allows for successful adaptation of adult techniques to pediatric patients. Specific considerations must be made in order to achieve safety and feasibility of RPN with selective clamping for renal preservation in cases of pediatric renal masses.

V8-04 PERCUTANEOUS EXTERNALLY ASSEMBLED LAPAROSCOPIC (PEAL) NEPHRECTOMY

INTRODUCTION AND OBJECTIVES: Concern exists regarding overuse of computed tomography (CT) children with nephrolithiasis. While guidelines for pediatric nephrolithiasis call for imaging such as plain film of the kidney-ureter-bladder (KUB) or renal ultrasound (US) to minimize ionizing radiation in both initial and follow-up management, little is known regarding follow-up imaging practices. We explored nationwide imaging patterns in children following emergency department (ED) evaluations for nephrolithiasis, hypothesizing that initial imaging choice and need for admission or readmission increase the risk of follow-up CT scans. METHODS: Claims from MarketScan (2007-2013), an employer-based dataset of privately insured patients, were used to assess children 1-18 presenting to the ED an acute nephrolithiasis event, defined as no prior ED visits or surgical interventions for nephrolithiasis within 6 months. Independent variables were age, gender, region of care and insurance status, initial imaging modality, need for hospital admission, and return ED visits. Primary outcome was imaging modality 90 days following an encounter. Appropriate imaging was defined as either KUB or US. Using logistic regression, odds for receiving CT or appropriate imaging in follow-up were calculated. RESULTS: A total of 871 children with an ED visit for nephrolithiasis met inclusion criteria. Median age was 16 (range 1-18) and the majority of patients were female (550, 63.0%). KUB was the most common initial modality (520, 59.7%) followed by CT (196, 22.5%) and US (150, 17.2%). A total of 282 (30.9%) children received no follow-up imaging. Of children receiving any follow-up imaging, appropriate imaging was obtained in 306 (51.9%) and CT obtained in 283 (48.0%) children. Of children initially receiving a CT, 79 (40.3%) had a CT in follow-up. Predictors for imaging patterns are shown in the Table. CONCLUSIONS: Overuse of CT in children with nephrolithiasis is not limited to initial presentation as one third of all children presenting to the ED received a CT in follow-up. Identifiable risk factors for followup CT include younger age, complexity of stone event, and region of care. Clinical pathways directing imaging strategies for pediatric nephrolithiasis should focus on follow-up imaging as well as initial evaluation.

PD19-05 THE OPTIMAL GUIDEWIRE TYPE AND EFFECT OF PRIOR USE ON THE EASE OF URETERAL STENT INSERTION

INTRODUCTION AND OBJECTIVES: A physical damage can occur to the neurovascular bundles during the procedure, due to the use of cautery and tractions. Nowadays bio-engineeringis developing novel devices with the aim of co-operate the neural renewal. Among them chitosan seems to be promising with neuro-regenerative properties. In our Institution we tried to use chitosan membranes as scaffold for neural renewal after nerve-sparingrobot-assisted radical prostatectomy (RARP). In laboratory setting results were promising so we designed a prospective studytrying to confirm chitosan properties inclinicalpractice. Primary end-point: to evaluate the feasibility of the application of chitosan membrane on neuro-vascular bundles after nerve-sparing RARP. Secondary end-point: To evaluate the recovery of erectile function at 1, 2, and 3 months postoperatively by performing a matched-pair analysis comparing the group of patients who underwent chitosan application to a control group who did not. METHODS: 47patients who underwent nerve sparing RARP (07/2015 01/2016) were enrolled. Criteria for inclusion was an IIEF>17. A control group of patients was selected. Potency recovery was defined as erection enough for intercourse or masturbation. Membranes were adequately prepared by immersion in saline solution and cutting. After that reconstructive phase of RARP was performed,chitosan membranes were introduced and applied on the bundles. RESULTS: Baseline data of patients in the Groups were comparable. Concerning intraoperative data, no modifications of operative time was recorded in the Chitosan Group;No intraoperative complications occurred. Postoperative complications rate was not affected by the application of the membrane. Concerning the functional data, a faster erectile function recovery was recorded in the cohort of patients who underwent chitosan application. CONCLUSIONS: In our experience, the application of chitosan membranes on the neurovascular bundles after robot-assisted RP was easy and safe. Preliminary functional outcomes showed a faster recovery of erectile function in the cohort of patients who underwent the application of the membranes. Larger sample size and randomized trials are needed in order to confirm these preliminary outcomes.

MP63-06 COMPARISON OF PATIENT RADIATION EXPOSURE DURING PERCUTANEOUS NEPHROSTOLITHOTOMY USING 3 DIFFERENT TECHNIQUES: A CADAVER STUDY

INTRODUCTION AND OBJECTIVES: Ureteral stent insertion is a frequent procedure in endourology, with no clear consensus on the best wire type to facilitate stent insertion. Use of wires may result in deterioration of their protective coating, requiring greater force for stent insertion. The purpose of this study was to identify the effect of wire type, and prior use, upon average insertion force needed for a 6Fr ureteral stent. METHODS: Stent insertion was tested using an ex vivo porcine urinary tract model with continuous water infusion (1cc/min) to simulate urine production. For each trial, a new, soft, 6Fr Cook JJ ureteral stent was advanced over new and used 0.03800 diameter guide wires including the Glidewire (Terumo), Standard Teflon-coated wire (Cook), Superstiff wire (Cook), Sensor wire (Boston Scientific), Zip-wire (Boston Scientific), and Zebra wire (Boston Scientific). A Mark-10 digital force gauge was attached to the stent, and at a constant advancing rate of 2 rotations per second, the forces to advance the stent over the wire were calculated. 10 trials of stent insertion were randomly performed on 12 new and 12 used guide wires (total of 240 placements). RESULTS: The new Glidewire had the lowest average force required for stent advancement (0.18N). The forces for insertion of all other new wires were significantly higher; Standard (1.25N; p<0.01), Superstiff (2.03N; p<0.01), Sensor (1.87; p<0.01), Zip (0.22N; p<0.01), and Zebra (0.61; p<0.01). When comparing the average insertion force between new and used wires, the used wires required greater mean force in the Standard (2.42N vs. 1.25N; p <0.01), Superstiff (2.68N vs. 2.03N; p <0.01), and Zipwire (0.36N vs. 0.22N; p <.01), but there was no statistical difference between used and new fibers in the Glidewire (0.28N vs. 0.18N; p1⁄40.14), Sensor ( 1.66N vs. 1.87N; p1⁄40.18) and Zebra wire (0.59N vs.0.61N; p1⁄40.67). CONCLUSIONS: The Glidewire resulted in the lowest force for ureteral stent insertion. It may be used several times with no significant effect on ureteral stent insertion force due its resilient lubricious hydrophilic coating. Employing a used Standard, Superstiff and Zip-wire may result in additional stent insertion force. Knowledge of the forces required for stent insertion over various guide wires may allow surgeons to improve the ease and safety of stent placement.