Do Flat Panel Detector C-Arms Decrease Radiation Exposure Compared to Conventional Image Intensifiers?

OBJECTIVE: To compare the radiation dose and image quality between flat panel detector (FPD) and traditional image intensifier (II) C-arms at their lowest radiation settings. METHODS: In a ureteroscopy simulation using a cadaver model, the radiation exposure was compared between FPD and II at 4 pulses-per-second (pps) using both low dose and automatic exposure control (AEC) settings. Additionally, the lowest dose settings for each machine were compared (4 pps with low dose in the FPD and 1 pps with low dose in the II). Five trials of 5 minutes were conducted for each setting. Four new optically stimulated luminescent dosimeters were used in each trial to record radiation exposure. Ten blinded urologists completed a survey rating image quality for each setting. RESULTS: When comparing the FPD and II at their lowest possible settings, the FPD produced significantly more radiation (P <.05). Using both machines at 4 pps in low dose mode resulted in no significant difference between C-arms (P >.05). Conversely, operating the C-arms at 4 pps and AEC resulted in significantly higher radiation exposure from the FPD compared to the II (P <.05). There was no significant difference in image quality at each setting. CONCLUSION: FPDs produce significantly more radiation at the lowest settings compared to IIs. Surgeons should employ IIs when reducing radiation exposure as low as possible is imperative, such as when operating on pediatric and pregnant patients.

Liposomal versus plain bupivacaine for pain control following vaginal reconstruction.

INTRODUCTION: Liposomal bupivacaine (LB) is a depot formulation of bupivacaine, which releases the drug over 72 hours to prolong local pain control. This retrospective study compares the effect of using LB versus plain bupivacaine on postoperative pain control, length of hospital stay and cost among patients undergoing vaginal reconstructive surgery. MATERIALS AND METHODS: Patients who underwent vaginal reconstructive surgery with levatorplasty and received an injection of 20 cc of either plain bupivacaine or LB for pudendal nerve block were included. The primary outcomes included postoperative narcotic use and subjective pain score. The secondary outcome was postoperative length of stay. Comparisons between groups were performed using the T test, Mann Whitney U and Chi-square tests with p < 0.05 considered significant. RESULTS: Between June 2016 and December 2021, 25 patients had received LB as a pudendal nerve block and 25 had received plain bupivacaine. Demographics between groups were similar. There was no difference between postoperative morphine equivalent dose (MED) for plain bupivacaine versus LB (25.3 ± 65.8 vs. 24.9 ± 31.7 MED; p = 0.159) or length of hospital stay (15.8 ± 12.0 hours vs. 23.8 ± 20.0; p = 0.094). Furthermore, subjective pain was also similar between groups (0 vs. 1.6 ± 2.6, p = 0.68), (4.6 ± 2.3 vs. 4.9 ± 2.0 average POD 1 pain, p = 0.534) and (4.3 ± 2.1 for vs. 4.9 ± 2.1 average POD 2 pain, p = 0.373). CONCLUSION: LB is not superior to plain bupivacaine for controlling pain following vaginal reconstructive surgery, and justification for the exponentially greater cost of LB is not supported. Prospective investigations with larger sample sizes are needed to determine the optimal pain management for levatorplasty in vaginal reconstructive surgery.

Multimodal Pain Control Utilizing Buprenorphine for Robotic-assisted Laparoscopic Prostatectomy: A Quality Improvement Comparison to Conventional Opioid Management.

INTRODUCTION: This study investigated the effectiveness of buprenorphine as an alternative to the use of conventional opioids perioperatively in an effort to help mitigate the impact of the use of perioperative conventional opioids for patients undergoing robotic-assisted laparoscopic prostatectomy. METHODS: Outcomes of patients with localized prostate cancer undergoing robotic-assisted laparoscopic prostatectomy were examined before and after implementation of novel quality improvement study that included receiving buprenorphine compared to conventional opioids for pain control intraoperatively and postoperatively. The primary end point was adequate pain control with secondary end points being analgesic consumption at home, opioid-related side effects, and patient satisfaction. RESULTS: When analyzing the secondary end point of oral morphine milligram equivalents, the buprenorphine group received significantly less morphine milligram equivalent compared to the conventional opioid group (15.19 vs 47.91, P = .006). The buprenorphine group also had lower reported pain scores at discharge (4.3; scale 1-10) compared to the conventional opioid group (5.4), though this did not reach significance (P = .069). In the buprenorphine group, 76.9% strongly agreed that their pain was adequately controlled in the hospital compared to 57.5% of the conventional opioid group (P = .223). There was no difference in overall satisfaction at postoperative day 5 (P = .358). CONCLUSIONS: Our study demonstrates buprenorphine's analgesic capabilities to maintain adequate pain control and patient satisfaction compared to conventional opioids during robotic-assisted laparoscopic prostatectomy, while decreasing perioperative opioid use.

Thulium versus holmium for in situ lower pole laser lithotripsy.

INTRODUCTION: During in situ lower pole laser lithotripsy, the dependent location may result in increased challenge fragmenting stones and a risk for stone regrowth if residual fragments remain. The purpose of this study was to compare the thulium fiber laser (TFL) with the holmium laser (HL) for in situ lower pole lithotripsy. MATERIALS AND METHODS: In a 3D printed kidney benchtop model, sixty 1 cm BegoStones were placed in the lower pole and fragmented in situ until fragments passed through a 2 x 2 mm mesh. Laser lithotripsy was performed using twelve energy, frequency and fiber size combinations and residual fragments were compared. In addition, laser fiber diameters and subsequent ureteroscope deflections and flow rates were compared between fibers. RESULTS: The TFL resulted in decreased residual fragments compared to the HL (11% vs. 17%, p < 0.001) and the three settings with least residual fragments were all TFL. Compared to the 150 µm TFL (265° deflection), there was a loss of 9° and 34° in the 200 µm TFL and 272 µm HL fibers, respectively. The measured fiber sizes were greater than manufacturer specified fiber size in every instance. Irrigation rates inversely correlated with fiber size. CONCLUSION: The TFL resulted in 35% less residual stone fragments, up to 34° additional deflection, and an increased irrigation rate when compared to the HL. Optimal fragmentation settings are identified to further improve lower pole lithotripsy. The combination of reduced residual fragments, improved deflection, and better flow rates make the TFL advantageous for in situ lower pole lithotripsy.

Does qSOFA score predict ICU admission and outcomes in patients with obstructed infected ureteral stones?

INTRODUCTION: Obstructing stones with infection represent a true urologic emergency requiring prompt decompression. Historically the systemic inflammatory response syndrome (SIRS) criteria has been used to predict outcomes in patients with sepsis. The quick Sequential Organ Failure Assessment (qSOFA) score has been proposed as a prognostic factor in patients with acute pyelononephritis associated with nephrolithiasis. However there has been limited application of qSOFA to patients undergoing ureteral stenting with obstructive pyelonephritis. The purpose of this study was to evaluate the predictive value of the qSOFA score for postoperative outcomes following renal decompression in this patient population. MATERIALS AND METHODS: A retrospective review was conducted at three medical centers within one academic institution to identify patients with obstructive pyelonephritis secondary to ureteral stones. All patients underwent emergent ureteral stent placement for decompression. The primary outcome was the predictive value of preoperative qSOFA score ≥ 2 for intensive care unit (ICU) admission postoperatively. Univariate analysis and multivariate regression analysis were performed to identify factors associated with postoperative outcomes, with p < 0.05 considered significant. RESULTS: Of the 289 patients who had ureteral stents placed, 147 patients met inclusion criteria. Twenty-four (16.3%) patients required ICU admission and there were 3 (2%) mortalities, all of these within the ICU admission group. The sensitivity and specificity of the qSOFA score ≥ 2 for ICU admission was 70.8% and 79.5% respectively which outperformed SIRS criteria, which had a sensitivity and specificity of 100% and 33.6% respectively. CONCLUSION: A preoperative qSOFA score ≥ 2 was a significant predictor for postoperative ICU admission in patients undergoing ureteral stent placement for obstructive pyelonephritis. The qSOFA score can be used to determine which patients will require ICU admission.

Single-stage Simultaneous Retrograde and Antegrade Endoscopic Treatment of Giant Prostatic and Bladder Urethral Calculi.

INTRODUCTION: Calculi encountered in the lower urinary tract typically reside within the bladder, less often in the urethra. In this video, we present a minimally invasive endoscopic approach for removal of the largest total stone volume in the lower urinary tract reported in the literature to date. METHODS: A 25-year-old male (body mass index 61 kg/m2) with neurogenic bladder presented with urosepsis and acute kidney injury secondary to obstructive uropathy. Computerized tomography (CT) of the abdomen and pelvis demonstrated bilateral severe hydroureteronephrosis, a 4.2-cm bladder stone, and 3 urethral stones, including a 7.7-cm prostatic urethral stone and 2 membranous urethral stones (Fig. 1). Urgent bilateral percutaneous nephrostomy tubes were placed. The patient elected for endoscopic management. RESULTS: The patient was placed in the supine lithotomy position. His buried penis and narrow urethra only accommodated a 16-French flexible cystoscope. Multiple stones were encountered in the membranous urethra. A 60-W SuperPulse Thulium Fiber laser at 2 J and 30 Hz was utilized to dust the urethral stones efficiently. Simultaneous ultrasound-guided percutaneous access into the bladder was obtained and ultrasonic lithotripsy via shockpulse was used to clear the bladder stone and prostatic stone from above. Total stone treatment time was 240 minutes. Suprapubic and urethral catheters were placed at the conclusion. Postoperative day 1 CT scan confirmed stone-free status and he was discharged postoperative day 2. Outpatient nephrostogram demonstrated patency of bilateral ureters and nephrostomy tubes were removed. CONCLUSION: Higher morbidity procedures including open or laparoscopic approaches have been described for management of large lower urinary tract stones. In this video, we demonstrate a minimally invasive approach of combined simultaneous antegrade and retrograde lithotripsy to achieve a stone-free status in this morbidly obese and complicated patient.

Guidewire type and prior use affects ureteral stent insertion force.

INTRODUCTION: To improve the success rate and safety of ureteral stent insertion, we sought to identify the effect of guidewire type and prior use upon the force needed to advance a 6Fr ureteral stent over various guidewires. MATERIALS AND METHODS: Two-hundred forty stent insertion trials were performed in an ex vivo porcine urinary tract model. Ten trials were randomly performed over 12 new and 12 used guidewires. For each trial, the force required to advance a 6Fr Cook double-pigtail ureteral stent was recorded. Guidewires included the Olympus Glidewire, Cook Fixed Core, and Boston Scientific Amplatz Super Stiff, Sensor, ZIPwire, and Zebra wire. RESULTS: The mean force needed for stent advancement was the lowest for the new Glidewire (0.18N) and ZIPwire (0.22N), with no significant difference to each other (p = 0.90). The following new wires required increasingly higher stent insertion forces compared to the Glidewire, the Zebra (0.60N; p < 0.01), Fixed Core (1.25N; p < 0.01), Sensor (1.43N; p < 0.01), and Amplatz Super Stiff wires (2.03N; p < 0.01). There was no statistical difference between new and used Glidewires (0.18N versus 0.29N; p = 0.14) and Zebra wires (0.59N versus 0.60N; p = 0.88). All other used wires required a significantly greater advancement force than their new counterparts (p < 0.01). CONCLUSIONS: For the same stent, the force required for stent advancement varies greatly between guidewire types. In addition, used guidewires typically required more force compared to new guidewires. In long or difficult cases, switching to a new wire may improve the ease of stent placement and reduce potential complications.

Should donors who have used marijuana be considered candidates for living kidney donation?

BACKGROUND: The use of marijuana in the USA has been steadily increasing over the last 10 years. This study is the first to investigate the effect of marijuana use by live kidney donors upon outcomes in both donors and recipients. METHODS: Living kidney donor transplants performed between January 2000 and May 2016 in a single academic institution were retrospectively reviewed. Donor and recipient groups were each divided into two groups by donor marijuana usage. Outcomes in donor and recipient groups were compared using t-test, Chi-square and mixed linear analysis (P < 0.05 considered significant). RESULTS: This was 294 living renal donor medical records were reviewed including 31 marijuana-using donors (MUD) and 263 non-MUDs (NMUD). It was 230 living kidney recipient records were reviewed including 27 marijuana kidney recipients (MKRs) and 203 non-MKRs (NMKR). There was no difference in donor or recipient perioperative characteristics or postoperative outcomes based upon donor marijuana use (P > 0.05 for all comparisons). There was no difference in renal function between NMUD and MUD groups and no long-term difference in kidney allograft function between NMKR and MKR groups. CONCLUSIONS: Considering individuals with a history of marijuana use for living kidney donation could increase the donor pool and yield acceptable outcomes.

How a Donor Nephrectomy Population Can Help Give Perspective to the Effects of Renal Parenchymal Preservation During Partial Nephrectomy.

Introduction: Volume of renal parenchymal loss is known to affect postoperative renal function after partial nephrectomy (PN). We utilize a novel comparison using donor nephrectomy (DN) patients to demonstrate the primary effect parenchymal volume loss plays on postoperative renal function following PN. Materials and Methods: Records of 250 living donor (DN) and 118 PN patients were retrospectively reviewed. Baseline characteristics and preoperative estimated glomerular filtration rate (eGFR)s were recorded. Percent changes in eGFR and incidences of surgically induced chronic kidney disease (CKD-S) in short, intermediate, and long-term postoperative periods were compared. Univariate and multivariate analyses of prognostic factors for development of CKD-S were performed. The PN group was further divided into subgroups with different lengths of warm ischemia time (WIT) and compared with DN patients. Results: At baseline, DN patients were younger, less likely to be male, had lower body mass index, lower American Society of Anesthesiologists, and higher preoperative eGFR (all p < 0.001). At hospital discharge, intermediate follow-up, and latest follow-up, renal function changes in DN and PN groups were -40.5% vs. -3.6%, -34.1% vs. -5.5%, and -33.2% vs. -4.4%, respectively (all p < 0.001). More DN than PN patients developed CKD-S (p < 0.001). DN was a significant risk factor for the development of chronic kidney disease on univariate and multivariate analyses (p < 0.001). On subgroup analysis, both subgroups with WIT 1 to 30 minutes and 31 to 60 minutes had less renal function decline at all time points compared with DN (p < 0.001). Conclusions: Volume of renal parenchyma retained is the dominant driver of postoperative renal function after nephrectomy, compared with all other factors. Surgeons should minimize parenchymal loss during PN to optimize postoperative renal function.

Impact of a Wireless System Upon Verbal Communication in a Simulated Robotic Operating Theater.

OBJECTIVE: To compare the efficacy of communication via the standard Da Vinci Si speaker system with a wireless, hands-free audio system in a prospective blinded study. METHODS: Nine hundred and sixty surgical phrases were spoken in a simulated robotic operating room (OR), including 480 phrases expressed via the Da Vinci Si speakers and 480 phrases expressed through a wireless, hands-free system. Using a dual console robotic system, communication was evaluated. Wireless headsets were given to the console and assistant robotic console surgeons, bedside assistant, anesthesiologist, and circulating nurse. An accurate response was defined as hearing the phrase correctly and transcribing it on a data sheet. The primary outcome was the number of correct phrases recorded during the study and secondary outcomes included subjective clarity and effectiveness of communication reported using a Likert scale. RESULTS: Overall, the wireless, hands-free system increased the accuracy of communication (390/480 [81.3%]) compared to the conventional robotic system (310/480 [64.4%]; P <.001). The bedside assistant, anesthesiologist, and circulating nurse had significantly fewer correct phrases recorded than the assistant robotic console surgeon when using the robotic speakers (P <.05 for all). In contrast, there were no significant differences in the number of correct phrases recorded between different positions when using the wireless system. Subjectively, the wireless system resulted in improved clarity and effectiveness of communication (P = .021; P <.001, respectively). CONCLUSION: Robotic operating systems have intrinsic barriers to effective communication between the surgeon and the rest of the operating room team. Improved communication could reduce surgical errors and improve patient safety.

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.

Efficacy of antegrade and retrograde warm saline pyeloperfusion during renal cryoablation for ureteral preservation.

OBJECTIVE: Cryoablation of renal tumors adjacent to the ureter or pelvicalyceal system carries risks for thermal injury of the collecting system. Although cold antegrade perfusion has been described for radiofrequency ablation, warm saline perfusion for renal cryoablation has not been well-characterized. The purpose of this study was to determine the safety and feasibility of antegrade and retrograde warm saline perfusions during percutaneous renal cryoablation. MATERIAL AND METHODS: A retrospective review was performed on 136 patients treated with percutaneous renal cryoablation at a single academic institution between 2009 and 2015. Six patients undergoing antegrade (n=3) or retrograde (n=3) warm saline perfusion for protection of the collecting system were identified. Warm saline was perfused through a 4 French nephrostomy tube in the antegrade technique and through a 6 French end-hole catheter in the retrograde technique. Outcome measures were tumor recurrence rates, success of urothelial preservation, hospital stay, blood loss and procedural time. RESULTS: Four tumors were in the lower pole and two tumors in the middle pole. The mean distance from tumor to ureter was 6.8 mm (0.8-11.5 mm) and no patient developed ureteral stricture. There was no tumor recurrence at a median follow-up of 37.3 months (7-65). The median procedural time was 3 hours and 13 minutes. One patient in each group developed minor complications (Clavien I and II) and there were no major complications. CONCLUSION: This study demonstrates the feasibility of antegrade and retrograde warm saline perfusion for ureteral preservation during cryoablation, without compromising oncologic outcomes.

Conventional vs Computer-Assisted Stereoscopic Ultrasound Needle Guidance for Renal Access: A Randomized Crossover Bench-Top Trial.

PURPOSE: Ultrasound (US) guidance during renal access and mass biopsy reduces radiation exposure, but can be technically challenging. A needle guidance system might simplify these procedures. The purpose of this randomized crossover trial was to compare conventional and computer-assisted US needle guidance systems for renal access and mass biopsy. MATERIALS AND METHODS: Seventy-one subjects were randomized to perform renal access or mass biopsy on a phantom using conventional and computer-assisted US guidance in a crossover study design. The primary outcome was success rate including subgroup analysis by experience level. Secondary outcomes included total procedure time, time to hit target, number of course corrections, and total punctures. In addition, subjective preferences of participants were also collected. RESULTS: Procedure success rate was higher with the computer-assisted US than with conventional US for both novice (98.0% (48/49) vs 81.6% (40/49); p < 0.001) and experienced US users (100% (22/22) vs 81.8% (18/22); p < 0.001). Computer-assisted US significantly shortened the total procedure time (94.0 seconds vs 192.9 seconds; p ≤ 0.001), time required to hit the target (62.5 seconds vs 121.6 seconds; p ≤ 0.001), and the number of course corrections (0.56 vs 2.89; p < 0.001) compared with conventional US. Computer-assisted US did not significantly reduce the number of needle punctures (1.75 vs 2.39; p = 0.132). Seventy-three percent of subjects preferred the computer-assisted US system. CONCLUSION: A computer-assisted needle guidance system increases effective US targeting for renal access and mass biopsy for novice and experienced users.

Jackets Off: The Impact of Laser Fiber Stripping on Power Output and Stone Degradation.

PURPOSE: To investigate the effect of laser fiber stripping on stone fragmentation and laser fiber power output. MATERIALS AND METHODS: In a benchtop simulation of laser lithotripsy, 20 BegoStone phantoms were positioned within a ureteral model and irradiated for 10 minutes at 8 Hz and 0.8 J. A freshly cleaved 365 µm laser fiber was used for all trials, with half of the fibers also undergoing stripping. Power output was measured at 1-minute intervals, beginning with an initial prelithotripsy recording at 0 minutes. Fiber tips were imaged with scanning electron microscopy. In a single-blinded manner, final masses of residual stone fragments were measured and used to quantify stone breakdown. Independent-sample Mann-Whitney U tests were performed with significance set at p < 0.05, comparing stripped and unstripped fiber tips with respect to power output and fraction of stone fragmentation. RESULTS: Mean power output after 1 minute of lasing was significantly greater in unstripped laser fibers (p = 0.015), while fibers, whether stripped or not, demonstrated no significant output differences prelithotripsy or at any time from 2 to 10 minutes. However, stripped laser fibers achieved significantly increased stone breakdown compared to unstripped fibers (p = 0.004), fragmenting 63 mg (25%) more of the initial stone mass per trial. CONCLUSIONS: Although unstripped laser fibers provided superior power output at 1 minute, output at all other time points was similar between stripped and unstripped fibers. However, despite similar optical output, stripped laser fibers achieved greater stone fragmentation, possibly due to improved contact between stone and fiber tip.

Predictors of narcotic use after percutaneous nephrolithotomy.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is associated with significant variability in postoperative pain and subsequent narcotic use. The purpose of this study was to determine the factors associated with high narcotic use following PCNL. MATERIALS AND METHODS: A single-center retrospective review of patients undergoing initial PCNL between 2004 and 2014 was performed. Preoperative, intraoperative and postoperative factors associated with postoperative narcotic usage were analyzed. The primary outcome variable was mean narcotic usage, standardized to intravenous morphine-equivalents. Patients in the lowest 75th percentile were compared to those in the highest 25th percentile. Univariate and multivariate statistical analyses were performed, with p < 0.05 considered significant. RESULTS: When the 243 patients were compared from lowest to highest quartile, total narcotic use during the first 48 hour period was 2.3, 8.4, 15.6, and 41.7 mg of morphine-equivalents. On univariate analysis, predictors of high narcotic use included age 20-39 (p < 0.001), preoperative narcotic use (p < 0.001), presence of a postoperative complication (p = 0.044), and high stone burden (p = 0.002). Age < 20 (p < 0.001) and > 60 years (p = 0.014) were associated with low narcotic use. On multivariate analysis, age 20-39 (OR 6.87, 95% CI 2.22-21.23, p = 0.001), male gender (OR 2.47, CI 1.05-5.81, p = 0.037), and preoperative narcotic use (OR 3.27, CI 1.41-7.60, p = 0.006) were associated with higher opioid requirement. CONCLUSION: Patients who were aged 20-39, males, and those with prior narcotic exposure used the highest doses of narcotics postoperatively. Knowledge of the factors predictive of high narcotic usage may allow better preoperative management of patient expectations and more effective postoperative care to prevent the complications of high narcotic usage.

Percutaneous Externally Assembled Laparoscopic vs Laparoendoscopic Single-Site Nephrectomy in a Porcine Model: A Prospective, Randomized, Blinded, Study.

OBJECTIVE: To compare the outcomes between laparoendoscopic single-site (LESS) and a novel percutaneous externally assembled laparoscopic (PEAL) nephrectomy in an in vivo porcine model. MATERIALS AND METHODS: Ten female farm pigs were randomized to LESS nephrectomy (5) or PEAL nephrectomy (5). Operative times, estimated blood loss, and intraoperative and postoperative complications were compared. The surgeons used a Likert scale to grade difficulty of peritoneal access, port placement, tool assembly, hilar dissection, closure, and overall difficulty of surgery. Scar assessment was performed by a blinded plastic surgeon using the Vancouver Scar Scale. Descriptive statistics were reported as median and range. The Mann-Whitney U test was used for continuous and ordinal variables. A p value <0.05 was considered significant. RESULTS: Median operative time was significantly shorter in the PEAL group vs the LESS group (85 minutes vs 127 minutes, p = 0.03). Median Likert scores showed overall hilar dissection and nephrectomy to be significantly easier using PEAL compared with LESS (2 vs 9, p < 0.01 for both). The PEAL instruments left no visible scar at 5 feet in any animal, and only 1 out of 10 scars could be identified on physical examination. CONCLUSIONS: The PEAL surgical paradigm demonstrates nearly scarless outcomes while providing shorter operative times and easier performance than LESS nephrectomy in a porcine model.

High-Frequency Dusting Versus Conventional Holmium Laser Lithotripsy for Intrarenal and Ureteral Calculi.

INTRODUCTION: The efficiency of holmium laser lithotripsy for urolithiasis depends upon several factors, including laser pulse energy and frequency and stone composition and retropulsion. This study investigates the complex interplay between these factors and quantifies lithotripsy efficiency using different laser settings in a benchtop kidney and ureter model. MATERIALS AND METHODS: In vitro caliceal and ex vivo porcine ureteral models were constructed. Calcium oxalate monohydrate stones were fragmented using a 200-µm laser fiber. In the caliceal model, stone fragmentation and vaporization rates at settings of 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz were compared. In the ureteral model, fragmentation time, retropulsion rate, fragmentation rate, and fragmented stone weight were compared at settings of 0.6 J/5 Hz and 0.2 J/15 Hz. Retropulsive forces generated at 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz settings were compared. Analysis was performed using Student's t-test and one-way ANOVA. RESULTS: In the caliceal model, the 0.6 J/5 Hz setting fragmented and vaporized stones at a higher rate than the 0.2 J/15 Hz setting (0.072 vs. 0.049 mg/s; p < 0.001). However, when the 0.2 J energy setting was combined with the 50 Hz frequency, the fragmentation rate (0.069 mg/s) was similar to the fragmentation rate at 0.6 J/5 Hz (0.072 mg/s; p = 0.677). In the ureteral model, the 0.6 J/5 Hz setting produced higher fragmentation rates (0.089 vs. 0.049 mg/s; p < 0.001), but resulted in significantly lower fragmented stone weight overall (16.815 vs. 25.485 mg; p = 0.009) due to higher retropulsion rates (0.732 vs. 0.213 mm/s; p < 0.001). Retropulsive forces decreased significantly when pulse energy decreased from 0.6 to 0.2 J (0.907 vs. 0.223 N; p < 0.001). Frequency did not affect retropulsive force at 15 and 50 Hz settings (0.223 vs. 0.288 N; p = 0.509). CONCLUSIONS: Laser lithotripsy of calcium oxalate monohydrate stones in the ureter should be performed using the low-energy, moderate-frequency dusting setting to minimize retropulsion and maximize efficiency. In the renal calix, the low-energy high-frequency setting performed similarly to the high-energy low-frequency setting.

Bench-Top Feasibility Testing of a Novel Percutaneous Renal Access Technique: The Laser Direct Alignment Radiation Reduction Technique (DARRT).

INTRODUCTION: Traditional techniques for obtaining percutaneous renal access utilize continuous fluoroscopy. In an attempt to minimize radiation exposure, we describe a novel laser direct alignment radiation reduction technique (DARRT) for percutaneous access and test it in a bench-top model. METHODS: In this randomized-controlled bench-top study, 20 medical personnel obtained renal accesses using both the conventional bullseye technique and the laser DARRT. The primary endpoint was total fluoroscopy time. Secondary endpoints included insertion time, puncture attempts, course corrections, and subjective procedural difficulty. In the laser DARRT, fluoroscopy was used with the C-arm positioned with the laser beam at a 30° angle. The access needle and hub were aligned with the laser beam. Effective caliceal puncture was confirmed with fluoroscopy and direct vision. The Paired samples Wilcoxon signed rank test was used for statistical analysis with significance at p < 0.05. RESULTS: A total of 120 needle placements were recorded. Fluoroscopy time for needle access using the laser DARRT was significantly lower than the bullseye technique in all groups as follows: attendings (7.09 vs 18.51 seconds; p < 0.001), residents (6.55 vs 13.93 seconds; p = 0.001), and medical students (6.69 vs 20.22 seconds; p < 0.001). Students rated the laser DARRT easier to use (2.56 vs 4.89; p < 0.001). No difference was seen in total access time, puncture attempts, or course corrections between techniques. CONCLUSION: The laser DARRT reduced fluoroscopy time by 63%, compared with the conventional bullseye technique. The least experienced users found the laser DARRT significantly easier to learn. This novel technique is promising and merits additional testing in animal and human models.

The Impact of Operating Room Noise Upon Communication During Percutaneous Nephrostolithotomy.

OBJECTIVE: Equipment and personnel contribute to the overall noise level in the operating room (OR). This study aims to determine intraoperative noise levels during percutaneous nephrostolithotomy (PCNL) and the effects of this noise upon intraoperative communication. METHODS: A PCNL benchtop model was used to measure intraoperative noise and determine its effect upon communication in three progressively increasing sound environments (baseline ambient noise, ambient noise with PCNL equipment, and ambient noise with both PCNL equipment and music). Five trials with 20 different medical words/phrases were spoken by the surgeon and responses were recorded by the first assistant, anesthesiologist, and circulating nurse. In addition, noise levels during PCNL were compared to common environmental noise levels. RESULTS: In the bench top model, noise levels were 53.49 A-weighted decibels (dBA) with ambient noise, 78.79 dBA with equipment in use, and 81.78 dBA with equipment and music. At the ambient noise level, the first assistant, anesthesiologist, and circulator correctly recorded 100%, 100%, and 96% of the words, respectively. The correct response rate by the subjects decreased to 97% (p = 0.208), 81% (p = 0.012), and 56% (p < 0.001) upon addition of PCNL equipment, and 90% (p = 0.022), 48% (p = 0.002), and 13% (p < 0.001) upon addition of music and PCNL equipment in the first assistant, anesthesiologist, and circulator, respectively. In the simulated OR model, PCNL noise level (81.78 dBA) was comparable to a passing freight train at 30 feet (82.2 dBA, p = 0.44). CONCLUSION: Noise pollution decreases effective intraoperative communication during PCNL. It is important for surgeons to understand the effect noise can have on attempted communication to prevent errors due to miscommunication. In addition, methods to decrease intraoperative noise pollution and improve communication in the OR could improve patient safety and outcomes.