Three-dimensional printed hydrogel model vs cadaver: comparing inflatable penile prosthesis training and evaluation.

BACKGROUND: Penile prosthesis implantation offers a durable, safe, and effective treatment option for male erectile dysfunction; however, many urologists feel apprehensive and uncomfortable placing penile prostheses due to limited training, low surgical experience, and intra- and postoperative complication management. AIM: To compare a previously validated hydrogel inflatable penile prosthesis (IPP) training model with cadaver simulations across 4 main categories: anatomic replication and realism, procedural replication and realism, educational effectiveness, and efficacy and safety. METHODS: An overall 88 participants (15 attendings, 18 fellows, and 55 residents) performed guided IPP placements on a cadaver and a hydrogel model. Based on a 5-point Likert scale, postsurveys were used to assess the participants' opinions regarding anatomic replication and realism, procedural replication and realism, educational effectiveness, and safety between the hydrogel model and cadavers. OUTCOMES: A direct head-to-head scenario was created, allowing participants to fully utilize the hydrogel model and cadaver, which ensured the most accurate comparison possible. RESULTS: A total of 84% agreed that the hydrogel model replicates the relevant human cadaveric anatomy for the procedure, whereas 69% agreed that the hydrogel tissue resembles the appearance of cadaveric tissue. Regarding the pubic bone, outer skin, corporal bodies, dartos layer, and scrotum, 79%, 74%, 82%, 46%, and 30% respectively agreed that the hydrogel tissue resembled the texture/behavior of cadavers. Furthermore, 66% of participants agreed that the hydrogel model replicates all the procedural steps. Specifically, participants agreed that the model replicates the skin incision/dartos dissection (74%), placement of stay suture and corporotomy (92%), corporal dilation (81%), measurement of prosthetic size (98%), reservoir placement (43%), IPP placement (91%), scrotal pump placement (48%), and skin closure (51%). Finally, 86%, 93%, and 78% agreed that the hydrogel model is useful for improving technical skills, as a teaching/practicing tool, and as an evaluation tool, respectively. To conclude, 81% of participants stated that they would include the hydrogel model platform in their current training. CLINICAL IMPLICATIONS: By replicating the IPP procedure, the hydrogel model offers an additional high-fidelity training opportunity for urologists, allowing them to improve their skills and confidence in placing penile prostheses, with the goal of improving patient surgical outcomes. STRENGTHS AND LIMITATIONS: The hydrogel training model allows users to perform the entire IPP placement procedure with high anatomic realism and educational effectiveness, maintaining many of the high-fidelity benefits seen in cadavers while improving safety and accessibility. CONCLUSION: Ultimately, this high-fidelity nonbiohazardous training model can be used to supplement and bolster current IPP training curriculums.

Application of IRIS Three-Dimensional Anatomical Models As Preoperative Surgical Planning Tools in the Management of Localized Renal Masses.

Introduction: The use of volume-rendered images is gaining popularity in the surgical planning for complex procedures. IRIS™ is an interactive software that delivers three-dimensional (3D) virtual anatomical models. We aimed to evaluate the preoperative clinical utility of IRIS for patients with ≤T2 localized renal tumors who underwent either partial nephrectomy (PN) or radical nephrectomy (RN). Patients and Methods: Six urologists (four faculty and two trainees) reviewed CT scans of 40 cases over 2 study phases, using conventional two-dimensional (2D) CT alone (Phase-I), followed by the CT + IRIS 3D model (Phase-II). After each review, surgeons reported their decision on performing a PN or an RN and rated (Likert scale) their confidence in completing the procedure as well as how the imaging modality influenced specific procedural decisions. Modifications to the choice of procedure and confidence in decisions between both phases were compared for the same surgeon. Concordance between surgeons was also evaluated. Results: A total of 462 reviews were included in the analysis (231 in each phase). In 64% (95% CI: 58-70%) of reviews, surgeons reported that IRIS achieved a better spatial orientation, understanding of the anatomy, and offered additional information compared with 2D CT alone. IRIS impacted the planned procedure in 20% of the reviews (3.5% changed decision from PN to RN and 16.5% changed from RN to PN). In the remaining 80% of reviews, surgeons' confidence increased from 78% (95% CI: 72-84%) with 2D CT, to 87% (95% CI: 82-92%) with IRIS (p = 0.02); this confidence change was more pronounced in cases with a high RENAL score (p = 0.009). In 99% of the reviews, surgeons rated that the IRIS accurately represented the anatomical details of all kidney components. Conclusion: Application of IRIS 3D models could influence the surgical decision-making process and improve surgeons' confidence, especially for robot-assisted management of complex renal tumors.

See Like an Expert: Gaze-Augmented Training Enhances Skill Acquisition in a Virtual Reality Robotic Suturing Task.

Introduction: The da Vinci Skills Simulator (DVSS) is an effective platform for robotic skills training. Novel training methods using expert gaze patterns to guide trainees have demonstrated superiority to traditional instruction. Portable head-mounted eye-trackers (HMET) offer the opportunity for eye tracking technology to enhance surgical robotic simulation training. Objective: To evaluate if training guided by expert gaze patterns can improve trainee performance over standard movement training techniques during robotic simulation. Methods: Medical students were recruited and randomized into gaze training (GT, n = 9) and movement training (MT, n = 8) groups. First, the participants reviewed an instructional video, with the GT group emulating expert gaze patterns and the MT group (n = 8) standard movement-based instruction. Training consisted of 10 repetitions of "Suture Sponge 3" on the DVSS while wearing HMET; the first three repetitions were followed by group-appropriate video coaching (gaze vs movement feedback), while the remaining repetitions were without feedback. Finally, two multitasking repetitions with a secondary bell-counting task were completed. Primary outcomes included DVSS scores during training and multitasking. Secondary outcomes included metrics collected from the HMET (gaze patterns and gaze entropy). Results: Total score, efficiency, and penalties improved significantly over the training in both groups; the GT group achieved higher scores on every attempt. Total scores in the GT group were higher than the MT group postvideo review (20.3 ± 21.8 vs 3.0 ± 6.2, p = 0.047), after coaching repetitions (61.8 ± 18.8 vs 30.1 ± 26.2, p = 0.01), and at the last training attempt (73.0 ± 16.5 vs 63.1 ± 17.4, p = 0.247). During multitasking, the GT group maintained higher total scores (75 ± 10.1 vs 63.3 ± 15.3, p = 0.01), efficiency (86.3 ± 7.4 vs 77.4 ± 11.2, p = 0.009), and superior secondary task performance (error: 6.3% ± 0.06 vs 10.7% ± 0.11, p = 0.20). Gaze entropy (cognitive-load indicator) and gaze pattern analysis showed similar trends. Conclusion: Gaze-augmented training leads to more efficient movements through adoption of expert gaze patterns that withstand additional stressors.

The Future of Penile Prosthetic Surgical Training Is Here: Design of a Hydrogel Model for Inflatable Penile Prosthetic Placement Using Modern Education Theory.

BACKGROUND: There is a significant need for a non-biohazardous, educational platform to equip and maintain the surgical skills required by urology trainees and low-volume implanters for inflatable penile prosthetic (IPP) placement. AIM: To design and develop an anatomic, hydrogel-based simulation platform for training and evaluate IPP placement using modern education theory. METHODS: The backward design concept was used as a framework in the design and development of an IPP simulation platform. Steps included delineating requirements from a physicians' perspective, translating requirements into engineering tasks (deliverables), developing a prototype, and pilot validation. Using a combination of 3-dimensional printing and hydrogel casting, a genitourinary tract model was constructed to replicate the appropriate steps of IPP placement guided by expert feedback. Full-immersion IPP simulations were performed through both infrapubic and penoscrotal approaches by 4 expert surgeons under operative conditions. Questionnaires evaluating the simulation's realism, value as a training tool, and further recommendations were completed. OUTCOMES: Using backward design educational pedagogy, a high-fidelity, full-procedural IPP simulation was fabricated and verified as an adequate educational tool for training and assessment. RESULTS: An expert consensus on the anatomic landmarks, steps and substeps, instruments, and errors to be included in the model was reached using a hierarchical task analysis and was successfully translated into a prototype hydrogel model. Experts performed all appropriate steps of IPP surgery and rated the simulation highly in terms of its realism and value as a training tool. On average, experts agreed that the model could function as a training tool, assessment tool, prerequisite for IPP accreditation, and requirement before live surgery. Experts stated they would have their trainees ideally complete an average of 1.75 models before live surgical training. All experts believed an operative checklist would be an ideal assessment tool. Witthaus MW, Saba P, Melnyk R, et al. The Future of Penile Prosthetic Surgical Training Is Here: Design of a Hydrogel Model for Inflatable Penile Prosthetic Placement Using Modern Education Theory. J Sex Med 2020;17:2299-2306.

A history of urolithiasis risk in space.

INTRODUCTION: The development of renal stones in space would not only impact the health of an astronaut but could critically affect the success of the mission. MATERIALS AND METHODS: We reviewed the medical literature, texts and multimedia sources regarding the careers of Dr. Abraham Cockett and Dr. Peggy Whitson and their contributions to the study of urolithiasis in space, as well as the studies in between both of their careers that helped to further characterize the risks of stone formation in space. RESULTS: Dr. Abraham T. K. Cockett (1928-2011) was Professor and Chair of the Department of Urology at the University of Rochester and served as AUA President (1994-1995). In 1962, Dr. Cockett was one of the first to raise a concern regarding astronauts potentially forming renal stones in space and suggested multiple prophylactic measures to prevent stone formation. Many of the early studies in this field used immobilized patients as a surrogate to a micro-gravity environment to mimic the bone demineralization that could occur in space in order to measure changes in urinary parameters. Dr. Peggy A. Whitson (1960-), is a biochemistry researcher and former NASA astronaut. She carried out multiple studies examining renal stone risk during short term space shuttle flights and later during long-duration Shuttle-Mir missions. CONCLUSION: From the early vision of Dr. Cockett to the astronaut studies of Dr. Whitson, we have a better understanding of the risks of urolithiasis in space, resulting in preventive measures for urolithiasis in future long duration space exploration.

Transvesical Versus Transabdominal - Which is the Best Approach to Bladder Diverticulectomy Using the Single Port Robotic System?

OBJECTIVE: Application of the Single Port (SP) robotic platform [Intuitive] is expanding. Using 2 illustrative examples of bladder diverticula (BD) resulting from bladder outflow obstruction (BOO), we describe in this video our techniques utilizing SP to treat BD via Extravesical (EV#1) and Transvesical (TV#2) approaches. METHODS: In EV#1, a 56-year old, with BOO due to benign prostate enlargement (BPE) of a 30 mL prostate, and a 5 cm BD, was treated with RABD-SP. A subumbilical SP access was used to approach and excise the BD in an EV fashion. The BPE was treated with Rezum. A 16 Fr urethral catheter was placed. In TV#2, a 67-year old, with urinary retention due to a 55 mL BPE and a 6 cm BD in the right posterolateral aspect adjacent the ureteric orifice, was treated with RABD-SP using a Gelport (no additional assistant ports). An open cut-down was performed onto a prefilled bladder and secured onto the abdominal wall with stay sutures. After draining the bladder, a Gelport was introduced into the bladder for SP docking with pneumo-vesical insufflation. Intravesical (inside-out) excision of the BD was performed with protection of the adjacent right ureteric orifice with an open access ureteral catheter. Utilizing the TV access, a simple prostatectomy was performed. A 22 Fr, 3-way catheter was placed at the end. RESULTS: For EV#1 and TV#2, estimated blood losses were 5 and 100 mL, length stay was 1 day in both, without any immediate perioperative complications. Both patients had successful trials of void on postoperative day 7 and 9, respectively. CONCLUSION: RABD-SP can be customized to treat BD, via transabdominal (extravesical) or transvesical (with bladder pneumo-insufflation) approaches, and combined with different BOO treatments (Rezum or simple prostatectomy, for instance), in a patient-specific personalized manner.

Incorporation and validation of clinically relevant performance metrics of simulation (CRPMS) into a novel full-immersion simulation platform for nerve-sparing robot-assisted radical prostatectomy (NS-RARP) utilizing three-dimensional printing and hydrogel casting technology.

OBJECTIVES: To incorporate and validate clinically relevant performance metrics of simulation (CRPMS) into a hydrogel model for nerve-sparing robot-assisted radical prostatectomy (NS-RARP). MATERIALS AND METHODS: Anatomically accurate models of the human pelvis, bladder, prostate, urethra, neurovascular bundle (NVB) and relevant adjacent structures were created from patient MRI by injecting polyvinyl alcohol (PVA) hydrogels into three-dimensionally printed injection molds. The following steps of NS-RARP were simulated: bladder neck dissection; seminal vesicle mobilization; NVB dissection; and urethrovesical anastomosis (UVA). Five experts (caseload >500) and nine novices (caseload <50) completed the simulation. Force applied to the NVB during the dissection was quantified by a novel tension wire sensor system fabricated into the NVB. Post-simulation margin status (assessed by induction of chemiluminescent reaction with fluorescent dye mixed into the prostate PVA) and UVA weathertightness (via a standard 180-mL leak test) were also assessed. Objective scoring, using Global Evaluative Assessment of Robotic Skills (GEARS) and Robotic Anastomosis Competency Evaluation (RACE), was performed by two blinded surgeons. GEARS scores were correlated with forces applied to the NVB, and RACE scores were correlated with UVA leak rates. RESULTS: The expert group achieved faster task-specific times for nerve-sparing (P = 0.007) and superior surgical margin results (P = 0.011). Nerve forces applied were significantly lower for the expert group with regard to maximum force (P = 0.011), average force (P = 0.011), peak frequency (P = 0.027) and total energy (P = 0.003). Higher force sensitivity (subcategory of GEARS score) and total GEARS score correlated with lower nerve forces (total energy in Joules) applied to NVB during the simulation with a correlation coefficient (r value) of -0.66 (P = 0.019) and -0.87 (P = 0.000), respectively. Both total and force sensitivity GEARS scores were significantly higher in the expert group compared to the novice group (P = 0.003). UVA leak rate highly correlated with total RACE score r value = -0.86 (P = 0.000). Mean RACE scores were also significantly different between novices and experts (P = 0.003). CONCLUSION: We present a realistic, feedback-driven, full-immersion simulation platform for the development and evaluation of surgical skills pertinent to NS-RARP. The correlation of validated objective metrics (GEARS and RACE) with our CRPMS suggests their application as a novel method for real-time assessment and feedback during robotic surgery training. Further work is required to assess the ability to predict live surgical outcomes.

Bladder oxidative stress in sleep apnea contributes to detrusor instability and nocturia.

PURPOSE: Obstructive sleep apnea is associated with voiding symptoms in humans and animals, and yet its effects on the urinary tract are poorly understood. We examined bladder structure and function, markers of oxidative damage and the redox survival pathway in a rat model of obstructive sleep apnea to identify changes. MATERIALS AND METHODS: To model obstructive sleep apnea we used a rat oxycycler system to create cyclical interruption in breathing oxygen, thereby producing intermittent hypoxemia. Male Sprague Dawley® rats were divided into an obstructive sleep apnea, a sham treated and a control group of 8 each. After 8-week exposure to obstructive sleep apnea conditions we assessed daytime and nighttime rat voiding behavior in metabolic cages. Cystometrograms were done and bladder tissue was processed for biochemical assays, enzyme-linked immunosorbent assay and transmission electron microscopy. RESULTS: Increased urinary frequency and total urine output developed in rats exposed to obstructive sleep apnea conditions. Cystometric changes included detrusor instability, bladder noncompliance and increased spontaneous contractions. These changes were associated with bladder oxidative stress characterized by significant increases in tissue levels of malondialdehyde and advanced oxidation protein products. Obstructive sleep apnea activated cell survival signaling manifested by increased expression of PI3K and phosphorylated Akt1. Transmission electron microscopy revealed marked ultrastructural damage to subcellular elements. CONCLUSIONS: Intermittent hypoxia in obstructive sleep apnea causes oxidative stress with ultrastructural and functional changes in the bladder. Sleep apnea related nocturia/voiding symptoms could be the result of these direct changes. Untreated sleep apnea has significant health consequences. Identifying urinary oxidative stress products in patients with nocturia may be useful as an economical noninvasive biomarker to identify undiagnosed obstructive sleep apnea.

Effect of ribavirin on viral kinetics and liver gene expression in chronic hepatitis C.

OBJECTIVE: Ribavirin improves treatment response to pegylated-interferon (PEG-IFN) in chronic hepatitis C but the mechanism remains controversial. We studied correlates of response and mechanism of action of ribavirin in treatment of hepatitis C. DESIGN: 70 treatment-naive patients were randomised to 4 weeks of ribavirin (1000-1200 mg/d) or none, followed by PEG-IFNα-2a and ribavirin at standard doses and durations. Patients were also randomised to a liver biopsy 24 h before or 6 h after starting PEG-IFN. Hepatic gene expression was assessed by microarray and interferon-stimulated gene (ISG) expression quantified by nCounter platform. Temporal changes in ISG expression were assessed by qPCR in peripheral-blood mononuclear cells (PBMC) and by serum levels of IP-10. RESULTS: After 4 weeks of ribavirin monotherapy, hepatitis C virus (HCV) levels decreased by 0.5±0.5 log10 (p=0.009 vs controls) and ALT by 33% (p<0.001). Ribavirin pretreatment, while modestly augmenting ISG induction by PEG-IFN, did not modify the virological response to subsequent PEG-IFN and ribavirin treatment. However, biochemical, but not virological, response to ribavirin monotherapy predicted response to subsequent combination treatment (rapid virological response, 71% in biochemical responders vs 22% non-responders, p=0.01; early virological response, 100% vs 68%, p=0.03; sustained virological response 83% vs 41%, p=0.053). Ribavirin monotherapy lowered serum IP-10 levels but had no effect on ISG expression in PBMC. CONCLUSIONS: Ribavirin is a weak antiviral but its clinical effect seems to be mediated by a separate, indirect mechanism, which may act to reset IFN-responsiveness in HCV-infected liver.

Temperature rise after peginterferon alfa-2a injection in patients with chronic hepatitis C is associated with virological response and is modulated by IL28B genotype.

BACKGROUND & AIMS: Interferon treatment for chronic hepatitis C is associated with non-specific symptoms including fever. We aimed to determine the association of temperature changes with interferon antiviral activity. METHODS: 60 treatment-naïve patients with chronic hepatitis C (67% genotype 1/4/6, 33% genotype 2/3) were admitted to start peginterferon alfa-2a and ribavirin in a clinical trial. Temperature was measured at baseline and 3 times daily for the first 24h and the maximal increase from baseline during that time (ΔTmax) was determined. Serum HCV-RNA, interferon-gamma-inducible protein-10 (IP-10) and expression of interferon-stimulated genes (ISGs - CD274, ISG15, RSAD2, IRF7, CXCL10) in peripheral blood mononuclear cells (PBMCs) were measured at very early time points, and response kinetics calculated. The IL28B single nucleotide polymorphism, rs12979860, was genotyped. RESULTS: Temperatures rose by 1.2±0.8°C, peaking after 12.5h. ΔTmax was strongly associated with 1st phase virological decline (r=0.59, p<0.0001) and was independent of gender, cirrhosis, viral genotype or baseline HCV-RNA. The association with 1st phase decline was seen in patients with rs12979860CC genotype (r = 0.65, p <0.0001) but not in CT/TT (r = 0.13, p = 0.53) and patients with CC genotype had a higher DTmax (1.4 ± 0.8 C vs. 0.8 ± 0.6 +C, p = 0.001). DTmax was associated with 6- and 24-h induction of serum IP-10 and of PBMC ISG expression, but only in patients with rs12979860CC [corrected].ΔTmax weakly predicted early virological response (AUC=0.68, CI 0.49-0.88). CONCLUSIONS: Temperature rise following peginterferon injection is closely associated with virological response and is modulated by IL28B polymorphism, reflecting host interferon-responsiveness.