Comparison of Pneumoperitoneum Stability Between a Valveless Trocar System and Conventional Insufflation: A Prospective Randomized Trial.

OBJECTIVE: To compare the variation in pneumoperitoneum and physiologic effects of patients undergoing laparoscopic renal surgery using the valveless trocar insufflation system (VI) vs a conventional insufflation system (CI). METHODS AND MATERIALS: We conducted a single-center, randomized controlled trial in patients undergoing renal surgery at 15 mm Hg insufflation using a VI system vs a CI system. The primary outcome measured was variation in insufflation pressure, and end-tidal CO2 at 10 and 25 minutes. RESULTS: Fifty-six patients (VI n = 28 or CI n = 28) met inclusion criteria and were randomized. There was significantly less variability in pressure readings, as measured by coefficient of variation, during VI compared to CI (7.8% vs 15.6%, P < .001). There was significantly less time spent within the range with pressure readings ≥18 mm Hg (median 0.2% vs 16.5%, P < .001) and ≤12 mm Hg (median 1.7% vs 5.6%, P = .011) during VI compared to CI. Additionally, there was significantly less time spent with pressure readings in the "unacceptable" range of ≥20 mm Hg (median 0% vs 0.08%, P < .001) and ≤10 mm Hg (median 0.09% vs 2.6%, P < .001) during the cases with VI compared to CI. End-tidal CO2 was significantly lower at 10 minutes (P = .036) after insufflation in the valveless trocar group compared to the conventional treatment group. There were no other significant differences in physiologic metrics. CONCLUSION: Compared with a CI, the VI provides a significantly more stable pneumoperitoneum during laparoscopic renal surgery and lower end-tidal CO2 at 10 minutes.

Crowd-Sourced Assessment of Technical Skills for Validation of Basic Laparoscopic Urologic Skills Tasks.

PURPOSE: The BLUS (Basic Laparoscopic Urologic Skills) consortium sought to address the construct validity of BLUS tasks and the wider problem of accurate, scalable and affordable skill evaluation by investigating the concordance of 2 novel candidate methods with faculty panel scores, those of automated motion metrics and crowdsourcing. MATERIALS AND METHODS: A faculty panel of surgeons (5) and anonymous crowdworkers blindly reviewed a randomized sequence of a representative sample of 24 videos (12 pegboard and 12 suturing) extracted from the BLUS validation study (454) using the GOALS (Global Objective Assessment of Laparoscopic Skills) survey tool with appended pass-fail anchors via the same web based user interface. Pre-recorded motion metrics (tool path length, jerk cost etc) were available for each video. Cronbach's alpha, Pearson's R and ROC with AUC statistics were used to evaluate concordance between continuous scores, and as pass-fail criteria among the 3 groups of faculty, crowds and motion metrics. RESULTS: Crowdworkers provided 1,840 ratings in approximately 48 hours, 60 times faster than the faculty panel. The inter-rater reliability of mean expert and crowd ratings was good (α=0.826). Crowd score derived pass-fail resulted in 96.9% AUC (95% CI 90.3-100; positive predictive value 100%, negative predictive value 89%). Motion metrics and crowd scores provided similar or nearly identical concordance with faculty panel ratings and pass-fail decisions. CONCLUSIONS: The concordance of crowdsourcing with faculty panels and speed of reviews is sufficiently high to merit its further investigation alongside automated motion metrics. The overall agreement among faculty, motion metrics and crowdworkers provides evidence in support of the construct validity for 2 of the 4 BLUS tasks.

Technique for office-based, ultrasonography-guided percutaneous biopsy of renal cortical neoplasms using a novel transducer for facilitated ultrasound targeting.

OBJECTIVES: To help clarify which small renal cortical neoplasms (RCNs) require surgery by using office-based, ultrasonography-guided percutaneous renal biopsy. PATIENTS AND METHODS: Biopsies were performed using facilitated ultrasound targeting (FUT) technology, which incorporates a needle guide and onscreen beam-steered technology to permit highly precise needle deployment. Patient and tumour characteristics, procedure time, complications and biopsy efficacy were documented. Wong-Baker pain levels were obtained before, during and 1 h after the procedure. RESULTS: Seven patients underwent biopsy, six for RCNs and one for medical renal disease. The mean (range) patient age was 68.5 (54-79) years, and the mean (range) tumour diameter was 2.55 (2.0-2.9) cm. Mean pain levels before, during and 1 h after the procedure were 0, 1.6 and 0.5, respectively. There were no intra- or post-procedural complications. Biopsy results were diagnostic in five of the six RCN cases and in the single case of medical renal disease. CONCLUSIONS: Our preliminary experience shows that office-based percutaneous renal biopsy using a novel transducer for FUT is safe and effective. An international multicentre study is planned to confirm these preliminary results.

Validation of the AUA BLUS Tasks.

PURPOSE: Standardized assessment of laparoscopic skill in urology is lacking. We investigated whether the AUA (American Urological Association) BLUS (Basic Laparoscopic Urologic Skills) skill tasks are valid to address this need. MATERIALS AND METHODS: This institutional review board approved study included 27 medical students, 42 urology residents, 18 fellows and 37 faculty urologists across 8 sites. Using the EDGE (Electronic Data Generation and Evaluation) device (Simulab, Seattle, Washington) 454 recordings were collected on peg transfer, pattern cutting, suturing and clip applying tasks, which together comprise the expert determined BLUS tasks. We collected synchronized video and tool motion data for each trial. For each task errors, time, path length, economy of motion, peak grasp force and EDGE score were collected. An expert panel of 5 faculty members performed GOALS (Global Objective Assessment of Laparoscopic Skills) evaluations on a representative subset of peg transfer and suturing skill tasks performed by 24 participants (IRR = 0.95). RESULTS: Demographically derived skill levels proved unsuitable to evaluate construct validity. Separation of mean scores by grouped skill levels was strongest for the suturing task. Objective motion metrics and errors supported construct validity vis-à-vis correlation with blinded expert video ratings (motion metrics R(2) = 0.95, p <0.01). Expert scores appeared to reward errors in suturing but not in block transfer. CONCLUSIONS: BLUS skill task performance scoring can discriminate among basic laparoscopic technical skill levels. Self-reported demographics are an unreliable source of determining laparoscopic technical skill.

Comparison of optics and performance of single channel and a novel dual-channel fiberoptic ureteroscope.

OBJECTIVE: To evaluate performance characteristics and optics of a novel dual-working channel fiberoptic ureteroscope (Wolf Cobra) with 2 single-channel fiberoptic ureteroscopes and to a single-channel distal sensor standard definition digital ureteroscope URF-V (SD-DS). METHODS: Four new ureteroscopes (Cobra, Viper, X(2), and SD-DS) were compared for active deflection, irrigation flow, and optical characteristics. We performed a porcine ureteroscopy and measured the time for cleaning the middle calyx after injection of 10 cc of a standardized bloody solution. RESULTS: The SD-DS showed a higher resolution (7.42 lines/mm; P = .0001) compared with the fiberoptic ureteroscopes; among the fiberoptic ureteroscopes, the Cobra had the highest resolution than the Viper and X(2) (P = .0001). Grayscale distribution and color representation were identical for the fiberoptic ureteroscopes, whereas the SD-DS provided a superior color representation and a significant higher depth of field. The Cobra provided superior flow with empty working channel (86 cc/min vs 68 cc/min [Viper] vs 62.5 cc/min [X(2)] vs 62 cc/min [SD-DS]; P = .0001) and with various accessories (P <.0001). With regard to deflection, the Storz X(2) and the Cobra provided superior deflection up and down (P <.0001). When evacuating a standardized bloody field, the Cobra provided significant shorter evacuation times compared with those of the Viper, X(2), and SD-DS (36.6 vs 72 vs 65.6 vs 72.6 seconds, respectively; P = .0001). CONCLUSION: The additional working channel of the Wolf Cobra may improve vision and performance during challenging ureteroscopic cases by providing an increased flow. The enhanced irrigation capabilities of the Cobra have to be balanced with a larger diameter of this ureteroscope.

Evaluation of the impact of three-dimensional vision on laparoscopic performance.

INTRODUCTION: Recent technological advancements have led to the introduction of new three-dimensional (3D) cameras in laparoscopic surgery. The 3D view has been touted as useful during robotic surgery, however, there has been limited investigation into the utility of 3D in laparoscopy. MATERIALS AND METHODS: We performed a prospective, randomized crossover trial comparing a 0° 3D camera with a conventional 0° two-dimensional (2D) camera using a high definition monitor (Karl Storz, Tuttlingen, Germany). All participants completed six standardized basic skills tasks. Quality testing scores were measured by the number of drops, grasping attempts, and precision of needle entry and exiting. Additionally, resolution, color distribution, depth of field and distortion were measured using optical test targets. RESULTS: In this pilot study, we evaluated 10 medical students, 7 residents, and 7 expert surgeons. There was a significant difference in the performance in all the six skill tasks, for the three levels of surgical expertise and training levels in 2D vs 3D except for the cut the line quality score and the peg transfer quality score. Adjusting for the training level, 3D camera image results were superior for the number of rings left (p=0.041), ring transfer quality score (p=0.046), thread the rings (no. of rings) (p=0.0004), and thread the rings quality score (p=0.0002). The 3D camera image was also superior for knot tying (quality score) (p=0.004), peg transfer (time in seconds) (p=0.047), peg transfer pegs left (p=0.012), and for peg transfer quality score (p=0.001). The 3D camera system showed significantly less distortion (p=0.0008), a higher depth of field (p=0.0004) compared with the 2D camera system. CONCLUSION: 3D laparoscopic camera equipment results in a significant improvement in depth perception, spatial location, and precision of surgical performance compared with the conventional 2D camera equipment. With this improved quality of vision, even expert laparoscopic surgeons may benefit from 3D imaging.

Comparison of optics and performance of a distal sensor high definition cystoscope, a distal sensor standard definition cystoscope, and a fiberoptic cystoscope.

OBJECTIVE: To evaluate performance characteristics and optics of a new generation high-definition distal sensor (HD-DS) flexible cystoscope, a standard-definition distal sensor (SD-DS) cystoscope, and a standard fiberoptic (FO) cystoscope. METHODS: Three new cystoscopes (HD-DS, SD-DS, and FO) were compared for active deflection, irrigation flow, and optical characteristics. Each cystoscope was evaluated with an empty working channel and with various accessories. Optical characteristics (resolution, grayscale imaging, color representation, depth of field, and image brightness) were measured using United States Air Force (USAF)/Edmund Optics test targets and illumination meter. We digitally recorded a porcine cystoscopy in both clear and blood fields, with subsequent video analysis by 8 surgeons via questionnaire. RESULTS: The HD-DS had a higher resolution than the SD-DS and the FO at both 20 mm (6.35 vs 4.00 vs 2.24 line pairs/mm) and 10 mm (14.3 vs 7.13 vs 4.00 line pairs/mm) evaluations, respectively (P <.001 and P <.001). Color representation and depth of field (P = .001 and P <.001) were better in the HD-DS. When compared to the FO, the HD-DS and SD-DS demonstrated superior deflection up and irrigant flow with and without accessory present in the working channel, whereas image brightness was superior in the FO (P <.001, P = .001, and P <.001, respectively). Observers deemed the HD-DS cystoscope superior in visualization in clear and bloody fields, as well as for illumination. CONCLUSION: The new HD-DS provided significantly improved visualization in a clear and a bloody field, resolution, color representation, and depth of field compared to SD-DS and FO. Clinical correlation of these findings is pending.

In vitro comparison of a novel facilitated ultrasound targeting technology vs standard technique for percutaneous renal biopsy.

OBJECTIVE: To improve the understanding of the epidemiology of renal cortical neoplasms through pretreatment biopsy, we evaluated a facilitated ultrasound targeting (FUT) technology. The technology allows a needle to be passed through the transducer probe and guided along a virtual dotted line on the monitor. We compared the FUT with standard percutaneous biopsy (PB) technique. MATERIALS AND METHODS: Forty-eight participants with various levels of training were recruited. Participants performed ultrasound-guided biopsies on phantom models using FUT and the standard biopsy technique in a randomized sequence. The phantom models consisted of pimento olives embedded in an opaque mold of Metamucil and Knox gelatin. Patients were given up to 10 attempts to achieve 3 complete specimens from the olives. Patients rated each biopsy technique. Results were stratified by level of experience. RESULTS: The mean time to obtain 3 complete biopsy specimens was significantly faster for FUT compared with the standard technique (140 seconds vs 246 seconds, P = .0001). The mean number of attempts needed to obtain 3 specimens was significantly less with FUT compared with the standard technique (4.3 vs 5.6 attempts, P = .0007). Patients reported that FUT was significantly easier to use compared with the standard technique (P = .0005). No significant order effect was observed. CONCLUSION: In this in vitro comparison, FUT increased the efficiency and efficacy of PB for users of all experience levels. FUT may allow urologists with limited PB experience to perform the procedure reliably and easily. Clinical evaluation of this technology is actively in progress.

Interobserver reliability and reproducibility of s.T.o.N.e. Nephrolithometry for renal calculi.

PURPOSE: To assess the reliability of the S.T.O.N.E. (stone size [S], tract length [T], obstruction [O], number of involved calices [N], and essence or stone density [E]) nephrolithometry scoring system by testing its reproducibility between different observers. PATIENTS AND METHODS: Preoperative images of 58 patients who underwent percutaneous nephrolithotomy (PCNL) were reviewed. Medical students, urology residents, one fellow, and a urology attending independently reviewed all images and scored the renal stones. Interobserver reliabilities of the total score for all categories and each component were evaluated by the intraclass correlation (ICC) and a κ coefficient. RESULTS: The interobserver reliability for the total score demonstrated high correlations for all components and total score (ICC=S, T, O, N, E and total 0.80, 0.97, 0.89, 0.84, 0.91, and 0.87, respectively). κ rates for individual components between two medical students were 0.36, 1, 0.31, 0.45, 0.33, and 0.30 for the S, T, O, N, E components and total score, respectively. κ values between the two urology residents were 0.71, 1, 0.92, 0.79, 0.93, and 0.67 for S, T, O, N, E components and total score, respectively. κ values between the urology fellow and an attending physician were 0.95, 1, 0.88, 0.94, 0.89, and 0.87 for S, T, O, N, E components and total score, respectively. P value for all the scoring components was <0.05, indicating that the estimated κ was not a result of chance. CONCLUSIONS: The S.T.O.N.E. nephrolithometry has excellent interobserver reliability. Quantifying the S and N metrics was the most challenging and least reliable. Standardized protocols to measure these components should be considered to improve accuracy and reproducibility of the scoring system.

In vitro randomized comparison of a standard and novel echogenic needle for ultrasonography-guided renal targeting.

BACKGROUND AND PURPOSE: Urologists are becoming increasingly aware of the importance of pretreatment percutaneous renal biopsy of small renal cortical neoplasms. A barrier to the routine performance of ultrasonography-guided percutaneous renal biopsy has been the technical challenges associated with the procedure. We evaluated a new modified needle, which incorporates an echogenic needle tip designed to improve the needle tip's visibility under ultrasonographic visualization. We evaluated and compared the ultrasonographic imaging quality of the echogenic needle (EN) and a standard needle (SN). METHODS: Forty-eight participants were recruited to perform ultrasonography-guided needle targeting and drainage of a simulated cyst within a phantom model. The simulated cysts were embedded in an opaque gel mold. Each participant was blinded to the type of needle being deployed and was asked to identify and aspirate the simulated cyst with each needle under ultrasonography guidance. Each needle was tested at three ultrasound-aiming angles, (0, 15, and 30 degrees). The quality of needle visibility under ultrasonographic imaging was assessed via a questionnaire, including needle preference and a visibility score (1-10) at each aiming angle. Participants were stratified by level of ultrasound experience. RESULTS: For each angle tested, the EN received higher visibility ratings. The mean visibility scores for the EN vs the SN were 6.44 vs 5.52 at 0 degrees (P=0.001), 7.77 vs 6.96 at 15 degrees (P=0.0004) and 8.33 vs 7.54 at 30 degrees (P=0.0001). Participants reported significantly greater comfort using the EN needle compared with the SN (P=0.001). These results held true regardless of the sequence of needle tested first. Also, there was a significant difference in visibility scores by angle (P=0.0001). Larger angles (30>15>0) resulted in higher scores. CONCLUSIONS: In this in vitro trial, the application of the EN improved needle visibility for users of all levels of experience. Clinical correlation is pending.

Tracking and assessment of technical skills acquisition among urology residents for open, laparoscopic, and robotic skills over 4 years: is there a trend?

BACKGROUND AND PURPOSE: Tracking the progression of technical skill acquisition during urology residency training is an essential yet challenging task that has been mostly based on anecdotal and subjective performance assessment. We evaluated five surgical tasks used at our institution to assess skill acquisition among residents over 4 consecutive years in an effort to determine appropriate skill testing for resident proficiency relative to level of training for future performance testing. METHODS: Urology residents were tested yearly throughout the course of their residency with five surgical tasks in an open, laparoscopic, and robotic format. The five tasks were: (1) rings on a peg, (2) thread the rings, (3) cut the line, (4) hexagonal suturing, and (5) suture and knot tying. Evaluation was performed by a trained instructor to assess quantity and quality of the skill task performance. RESULTS: The highest scores were obtained on all open tasks regardless of training level. Residents performed second best on robotic and lowest on the laparoscopic skill tasks. The score difference among surgery platforms was statistically significant P<0.0005 across all tasks. It was Tasks 2 and 5, however, that showed a statistically significant difference in overall quantity×quality score between different postgraduate year (PGY) residents (P=0.03 and P=0.02). In addition, the quantity score for Task 5 also showed a statistically significant difference among PGY residents (P=0.04). There was no statistically significant difference in time to perform tasks among PG years. CONCLUSIONS: The high-level Tasks 2 and 5 were the most useful in differentiating different levels of skill task competency among urology residents and appear to be most useful in assessing the degree of improvement among residents during training. These tasks have subsequently been worked into our institution's testing curriculum.