Multilayered hydrogel scaffold construct with native tissue matched elastic modulus: A regenerative microenvironment for urethral scar-free healing.

The unsuitable deformation stimulus, harsh urine environment, and lack of a regenerative microenvironment (RME) prevent scaffold-based urethral repair and ultimately lead to irreversible urethral scarring. The researchers clarify the optimal elastic modulus of the urethral scaffolds for urethral repair and design a multilayered PVA hydrogel scaffold for urethral scar-free healing. The inner layer of the scaffold has self-healing properties, which ensures that the wound effectively resists harsh urine erosion, even when subjected to sutures. In addition, the scaffold's outer layer has an extracellular matrix-like structure that synergizes with adipose-derived stem cells to create a favorable RME. In vivo experiments confirm successful urethral scar-free healing using the PVA multilayered hydrogel scaffold. Further mechanistic study shows that the PVA multilayer hydrogel effectively resists the urine-induced inflammatory response and accelerates the transition of urethral wound healing to the proliferative phase by regulating macrophage polarization, thus providing favorable conditions for urethral scar-free healing. This study provides mechanical criteria for the fabrication of urethral tissue-engineered scaffolds, as well as important insights into their design.

Risk of Glans Dehiscence Associated with Vascular Flap Coverage of the Glanular Neourethra during Primary Urethroplasty: A Randomised Controlled Trial.

BACKGROUND: Hypospadias is one of the common congenital anomalies of male genitalia. Although over 300 different operative techniques have been described, post-operative complications are still common, of which glans dehiscence (GD) is the most severe complication requiring redo urethroplasty. Some surgeons use the vascular flap to cover the glanular part of the neourethra to prevent GD, but there are controversies regarding its usefulness. There is a paucity in the literature, about articles evaluating the risk of GD associated with vascular flap coverage of the glanular neourethra during primary urethroplasty. MATERIALS AND METHODS: We planned a single-blinded, parallel-design, randomised controlled trial involving 56 cases of hypospadias treated with single-stage urethroplasty amongst the admitted cases of hypospadias for primary urethroplasty in the Department of Paediatric Surgery, AIIMS, Bhubaneswar, from November 2017 to December 2019 as an M.Ch. thesis project. This was approved by the Institutional Ethics Committee and enrolled in the national registry of clinical trial. 28 patients were randomised into Group A (without flap coverage of the glanular part of the neourethra) and 28 patients were randomised into Group B (with flap coverage of the glanular neourethra). RESULTS: Only 2 (7.1%) cases amongst the Group A patients developed GD, while 9 (32.1%) cases of Group B had GD (P = 0.013). CONCLUSIONS: Extending the vascular flap coverage up to the glanular part of the neourethra till the neo-meatus during primary urethroplasty is significantly associated with GD.

Rare vesicourethral foreign body caused by sexual eccentricity - case report.

BACKGROUND: There are many types of foreign bodies in the bladder and urethra. The most common way is to insert foreign bodies through the external urethra by oneself or by others. It is often seen in situations such as masturbation, mental disorder, curiosity, etc. This article discusses the clinical diagnosis and treatment methods and preventive measures for foreign bodies in the bladder and urethra caused by sexual fetishes. CASE PRESENTATION: This article introduces a rare case. The patient was a 54-year-old male who inserted a thermometer into his urethra during masturbation and could not remove it. During the operation, we tried various methods to remove the thermometer many times, but due to the angle of the thermometer embedded in the bladder and urethra and the smooth tip of the thermometer, it could not be removed with foreign body forceps. Finally, a homemade negative pressure aspirator (consisting of a section of infusion tube and a 50 ml syringe) was used to completely remove the thermometer from the bladder and urethra. The Written informed consent was obtained from patient did not experience complications such as mercury leakage and bladder and urethral perforation. A telephone follow-up 4 months later showed that the patient urinated smoothly without discomfort such as frequent urination and urgency. DISCUSSION: There are many types of vesicourethral foreign bodies. When treating vesicourethral foreign bodies clinically, these can be removed through endoscopy, laparoscopy or open surgery according to the size, type and nature of the foreign bodies. At the same time, in order to effectively prevent the occurrence of bladder and urethra foreign bodies, sex education should be vigorously promoted.

Trends of chlamydia and gonorrhea infections by anatomic sites among men who have sex with men in south China: a surveillance analysis from 2018 to 2022.

BACKGROUND: Chlamydia and gonorrhea notifications are rapidly rising in men who have sex with men (MSM). Currently, there are limited data on the prevalence of chlamydia and gonorrhea across various anatomical sites. Our study aimed to explore the prevalence, association and changing trends of urethral and rectal chlamydia and gonorrhea among MSM in Guangdong Province, China. METHODS: We analyzed data among MSM attending sexually transmitted infections (STI) clinics in the Guangdong governmental sentinel network between 2018 and 2022. Chi-square tests were used to compare the difference, Join-point regressions for analyzing changing trends, and multivariate logistic regressions for examining associated factors. RESULTS: We included 4856 men in the analysis. Rectal chlamydia significantly increased from 13.8% to 26.4% over the past 5 years (average annual percentage change [AAPC] 19.2%, 95%CI 1.0-40.6, p = 0.043). After adjusting for covariates, chlamydia infection positively associated with main venue used to seek sexual partners (aOR = 2.31, 95%CI 1.17-4.55), having regular sexual partners in the past 6 months (aOR = 3.32, 95%CI 1.95-5.64), receiving HIV counselling and testing services (aOR = 2.94, 95%CI 1.67-5.17), receiving peer education (aOR = 1.80, 95%CI 1.14-2.83), infection with syphilis (aOR = 2.02, 95%CI 1.02-4.01) and infection with gonorrhea (aOR 7.04, 95% CI 3.01-16.48). Gonorrhea infection positively associated with having regular sexual partners in the past 6 months (aOR = 3.48.95%CI 1.16-10.49), and infection with chlamydia (aOR 7.03, 95% CI 2.99-16.51). CONCLUSIONS: To conclude, our findings reveal a high prevalence of chlamydia infections among MSM, particularly in the rectal area. Comprehensive chlamydia and gonorrhea health services are necessary for MSM to improve sexual health.

The role of prostatic urethral angle and intravesical prostatic protrusion on surgical capsule calculi formation in the prostate: A retrospective study.

PURPOSE: To investigate the relationship between prostatic urethral angle (PUA) and the development of surgical capsule calculi (SCC) within the prostate, and to examine the presence and impact of intravesical prostatic protrusion (IPP). MATERIALS AND METHODS: A retrospective analysis was conducted on 90 patients who underwent radical prostatectomy, with preoperative assessments using both transrectal ultrasound of the prostate (TRUS) and magnetic resonance imaging. Patients were divided into groups with and without SCC and further categorized into type 1 and type 2 stones based on the location and severity of the calculi. Statistical analysis included chi-square and independent sample t-tests, with p<0.05 considered significant. RESULTS: Of the patients, 82.2% were diagnosed with SCC. No significant difference in PUA was found between patients with and without SCC. However, a notable disparity in IPP presence was observed, suggesting an inverse correlation with SCC development. Additionally, no significant differences were identified when comparing the two types of SCC based on PUA and IPP measurements. CONCLUSIONS: The presence of IPP exhibited an inverse relationship with SCC, suggesting diminished urine flow pressure over the prostatic urethra may reduce the likelihood of SCC formation. However, no direct association between PUA and the presence or severity of SCC was identified. These findings highlight the complexity of factors contributing to prostatic calculi development and the potential role of IPP in this context.

Assessment of Combined Resection-Anastomosis and Urethropexy in Dogs with Urethral Prolapse.

The literature regarding surgical repair of urethral prolapse in dogs is limited and associated with a high recurrence rate. We hypothesized that combined resection and anastomosis (R&A) with urethropexy would be associated with less recurrence of urethral prolapse compared with R&A alone. Medical records of dogs managed surgically for urethral prolapse were reviewed (2013-2023) from three tertiary care hospitals. Inclusion criteria included complete medical records, including surgery reports, short-term postoperative complications, and longer-term follow-up. Forty-six male dogs successfully met the inclusion criteria (16 castrated; 30 intact). Brachycephalic breeds were overrepresented (37/46, 80%). Surgical repair by R&A alone (n = 27), urethropexy alone (n = 6), or a combined R&A and urethropexy (n = 13) was performed. Recurrence rates for these techniques were 13/27 (48%), 2/6 (33%), and 1/13 (8%), respectively. The recurrence rate of urethral prolapse treated by a combined R&A and urethropexy was significantly lower (P < .05) than R&A alone, despite more dogs being overweight and less surgeon experience (each P < .05). Interestingly, dogs neutered before initial diagnosis may be more likely to have postoperative recurrence. Considering general anesthesia risks, an initial combination procedure for urethral prolapse may help prevent recurrence.

What maximal urethral closure pressure threshold predicts failure of mid-urethral sling surgery?

OBJECTIVE: Low Maximal Urethral Closure Pressure (MUCP) is linked to unfavourable outcome of anti-incontinence surgery, however the cut-off value varied within studies. This study aimed to predict the cut-off value of MUCP that contributes to poor outcome of Mid-Urethral Sling (MUS) surgery in Urinary Stress Incontinence (USI) patients. MATERIALS AND METHODS: Records of 729 women underwent MUS procedure from January 2004 to April 2017 reviewed. Patients were divided into four MUCP groups, which were <20 cmH2O (≥20 and < 40) cmH2O (≥40 and ≤ 60) cmH2O and >60 cmH2O. Objective evaluation comprising 72-h voiding diary, multichannel urodynamic study (UDS) and post-operative bladder neck angle measurement. Subjective evaluation through validated urinary symptoms questionnaires. Primary outcome was objective cure rate of negative urine leak on provocative filling cystometry and 1-h pad test weight <2 g, and subjective cure rate was negative response to question 3 of UDI-6. Secondary outcome was identifying risk factors of cure failure for MUS in low MUCP groups. To identify the risk factors of cure failure, MUCP groups were narrowed down into <40 cmH2O or ≥40 cmH2O. RESULTS: Total of 688 women evaluated. Overall objective cure rate was 88.2% with subjective cure rate of 85.9%. Objective and subjective cure rates were lower in groups with low MUCP <40 cmH2O. Failure of MUS correlate significantly in patients with low MUCP <40 cmH20, bladder neck angle <30° and Functional urethral length (FUL) < 2 cm. CONCLUSION: Women with MUCP <40cmH2O, bladder neck angle <30° and FUL < 2 cm are more likely to have unfavorable outcome following MUS surgery. We proposed the cut-off low MUCP <40cmH2O as predictor for fail MUS surgery in SUI patients.

Safety and efficacy of lasers compared to cold knife in direct visual internal urethrotomy: a systematic review and Meta-analysis.

Cold knife urethrotome was introduced in 1971 and it had an 80% success rate. New advancements in this field have shed light on the use of various lasers such as carbon dioxide, Nd: YAG, KTP, Argon, Ho: YAG, and excimer lasers. It has been observed that cold knife urethrotomy has a higher recurrence rate than laser urethrotomy, but the superiority of either treatment modality has not been established yet. Data were thoroughly searched through PubMed, Scopus, and clinicaltrials.gov. We also used clinicaltrials.gov for ongoing and published research. The data was analyzed via R studio version 2023.12.1 (oceanstorm). For dichotomous variables, Odds Ratio (OR) were used to pool data and standardized mean difference was used for continuous variables with 95% confidence intervals (CIs). A total of 14 studies including 1114 participants were included in this meta-analysis. The results of the combined analysis revealed significant relation with a mean difference of 0.99 (95% CI: 0.37; 1.62), and favored laser group. The overall results have shown the laser to have a significant favorable profile demonstrating a recurrence, Odds Ratio of 0.42 (95% CI:0.27;0.65). Patients with laser therapy had a lower risk of complication rate (OR 0.49, 95% Cl: 0.35; 0.67). All the findings obtained by the analysis in this study favour lasers significantly over the cold knife technique especially when mean Qmax, with recurrence and complications taken into account.

The Effect of Botulinum Toxin (Masport) Injection Following Internal Urethrotomy of Bulbar Urethral Stricture: A Pilot Study.

The application of Botulinum toxin (Masport) in urology has a long history. We aimed to assess the effect of local Masport on improvement in patients with urethral stricture by reducing the recurrence of urethral stricture. This pilot study conducted was a double-blind randomized clinical trial with code IRCT20191222045852N1 on patients suffering from urethral stricture. Finally, 28 patients were allocated to intervention and control groups. Twelve patients received intralesional injection with Masport in addition to internal urethrotomy, while 16 patients underwent internal urethrotomy with normal saline. The Cox regression hazard model was used to evaluate the effect of treatment status on recurrence time adjusted for the age, length, and location of the stenosis, cause of the stenosis, and history of previous operations. The effect of treatment type was significant at the .05 level. The past medical history and cause of urethral stricture had a significant impact on relapse-free survival. Also, the improvement in the mean score of the EuroQol Visual Analogue Scale (EQ-VAS), International Prostate Symptom Score (IPSS), and Q-max in the group with Masport was significantly different from the group with normal saline. The internal urethrotomy with intralesional injection of Masport has a better survival prognosis than internal urethrotomy with normal saline group. Therefore, the authors suggest that, given this successful initial clinical trial, consideration be given to future studies involving the use of botox in the management of urethral strictures in conjunction with internal urethrotomy.

Revisiting the external urethral sphincter: new anatomical insights from a human cadaver study.

PURPOSE: The external urethral sphincter (EUS) is critical for urinary continence, but its complex anatomy is not fully understood, complicating its preservation during prostate surgeries. This study aims to elucidate the anatomy and development of the EUS to enhance surgical techniques for continence preservation. METHODS: The study consisted of a postmortem examination of three male cadavers, aged 52, 64, and 60, with intact urogenital systems. Specimens including the prostate and EUS were dissected, fixed in formalin, and stained with Hematoxylin-Eosin for microscopic analysis. Histological assessments focused on the muscle composition and structure of the EUS and prostate. RESULTS: Macroscopic examination revealed symmetrical prostates without pathologies. Histologically, the anterior prostate lacked tubuloalveolar glands, showing striated muscle fibers from the external urethral sphincter extending into the prostate and prostatic urethra. Reduced glandular structure and prevalent smooth muscle were noted. This intricate integration of striated muscle fibers at the EUS-prostate interface underscores the anatomical complexity vital for surgical preservation of urinary continence. CONCLUSION: Our study reveals a complex EUS-prostate relationship, challenging the view of the EUS as merely a circular muscle. The findings demonstrate the importance of the EUS's extension into the prostate for urethral stabilization and continence. Recognizing this anatomy is crucial for maintaining urinary continence in prostate surgeries and enhancing postoperative outcomes.

The bacterial displacement test: an in vitro microbiological test for the evaluation of intermittent catheters and urinary tract infection.

AIMS: Intermittent catheters (ICs) are commonly used in bladder management, but catheter-associated urinary tract infections (CAUTIs) remain challenging. Insertion tips may reduce the risk of CAUTIs by minimizing bacterial transfer along the urinary tract. However, there are few laboratory tests to evaluate such technologies. We describe the use of an adapted in vitro urethra agar model to assess bacterial displacement by ICs. METHODS AND RESULTS: Simulated urethra agar channels (UACs) were prepared with catheter-specific sized channels in selective media specific to the challenge organisms. UACs were inoculated with Escherichia coli and Enterococcus faecalis before insertion of ICs, and enumeration of UAC sections was performed following insertion. Four ICs were evaluated: Cure Catheter® Closed System (CCS), VaPro Plus Pocket™, Bard® Touchless® Plus, and SpeediCath® Flex Set. CCS demonstrated significantly reduced bacterial displacement along the UACs compared to the other ICs and was also the only IC with undetectable levels of bacteria toward the end of the UAC (representing the proximal urethra). CONCLUSION: The bacterial displacement test demonstrated significant differences in bacterial transfer between the test ICs with insertion tips, which may reflect their different designs. This method is useful for evaluating CAUTI prevention technology and may help guide future technology innovations.

Checking vesicourethral anastomosis for urinary extravasation during radical prostatectomy: is it still necessary in the robotic era? A prospective, randomized case-control study.

PURPOSE: This study aims to evaluate the role of intraoperative control of the watertightness of vesicourethral anastomosis extravasation control (VUAEC) in predicting vesicourethral anastomosis (VUA) healing and early postoperative outcomes in patients undergoing robot-assisted radical prostatectomy (RARP). METHODS: 100 patients who underwent RARP between October 2020 and May 2023 were consecutively included in the study. Preoperatively, the patients were randomized to undergo VUAEC (Group-A) or not (Group-B). Patients in Group-A were evaluated in 2 subgroups: those with no extravasation observed during VUAEC (Group-A1; n = 31 (62%)) and those with extravasation (Group-A2; n = 19 (38%)). On the 8th post-operative day, a gravity cystogram (GC) was performed on all patients to assess VUA healing. RESULTS: There was no statistically significant difference between the groups in terms of clinical features, drain removal time, length of hospital stay, extravasation on GC, catheter removal time and postoperative complications (p > 0.05, for each). There was also no statistically significant difference between the subgroups in terms of drain removal time, length of hospital stays, catheter removal time (p > 0.05, for each). In Group-A2, urinary extravasation on GC was found in a greater percentage, but the difference remained statistically insignificant (p = 0.082). CONCLUSIONS: Performing intraoperative VUAEC did not have a significant role in the prediction of VUA healing and early postoperative outcomes in patients undergoing RARP. The current study did not identify a substantial clinical benefit of routine intraoperative VUAEC.

Prognostic significance of residual tumor at restaging transurethral bladder resection in high-risk non-muscle-invasive bladder cancer.

PURPOSE: To assess prognostic significance of residual tumor at repeat transurethral resection (reTUR) in contemporary non-muscle-invasive bladder cancer (NMIBC) patients. METHODS: Patients were identified retrospectively from eight referral centers in France, Italy and Spain. The cohort included consecutive patients with high or very-high risk NMIBC who underwent reTUR and subsequent adjuvant BCG therapy. RESULTS: A total of 440 high-risk NMIBC patients were screened, 29 (6%) were upstaged ≥ T2 at reTUR and 411 were analyzed (T1 stage: n = 275, 67%). Residual tumor was found in 191 cases (46%). In patients with T1 tumor on initial TURBT, persistent T1 tumor was found in 18% of reTUR (n = 49/275). In patients with high-grade Ta tumor on initial TURBT, T1 tumor was found in 6% of reTUR (n = 9/136). In multivariable logistic regression analysis, we found no statistical association between the use of photodynamic diagnosis (PDD, p = 0.4) or type of resection (conventional vs. en bloc, p = 0.6) and the risk of residual tumor. The estimated 5-yr recurrence and progression-free survival were 56% and 94%, respectively. Residual tumor was significantly associated with a higher risk of recurrence (p < 0.001) but not progression (p = 0.11). Only residual T1 tumor was associated with a higher risk of progression (p < 0.001) with an estimated 5-yr progression-free survival rate of 76%. CONCLUSIONS: ReTUR should remain a standard for T1 tumors, irrespective of the use of en bloc resection or PDD and could be safely omitted in high-grade Ta tumors. Persistent T1 tumor at reTUR should not exclude these patients from conservative management, and further studies are needed to explore the benefit of a third resection in this subgroup.

Expert classification of hypospadias: an external validation and evaluation of agreement for Glans-Urethral Meatus-Shaft (GMS) and Hypospadias Objective Penile Evaluation (HOPE) scores.

PURPOSE: This study evaluates the inter-rater agreements of both the Glans-Urethral Meatus-Shaft (GMS) hypospadias score and Hypospadias Objective Penile Evaluation (HOPE) score, aiming to standardize disease classification for consistent agreement in clinically relevant characteristics of hypospadias. METHODS: Photos of hypospadias in children were collected from two separate institutions. Three raters scored the photos using GMS and HOPE, excluding penile torsion and curvature assessment in HOPE due to photo limitations. RESULTS: A total of 528 photos were included. With GMS, Fleiss' multi-rater kappa showed an agreement of 0.745 for glans-urethral plate, 0.869 for meatus, and 0.745 for shaft. For HOPE scores, the agreements were 0.888 for position of meatus, 0.669 for shape of meatus, 0.730 for shape of glans, and 0.708 for the shape of the skin. The lower agreement in the shape of the meatus evaluation may be attributed to the lack of a quantitative classification method in HOPE. Experts rely on their subjective judgment based on the provided example photos and their index patient. CONCLUSIONS: While there is high agreement among experts when evaluating hypospadias using the GMS and HOPE scoring criteria, only the position of the meatus achieved nearly perfect agreement highlighting that the current scoring systems entail a subjective element in disease classification.

UroLift to preserve seminal parameters in young male with LUTS from BPH.

PURPOSE: Prostatic urethral lift has been an effective ejaculation sparing treatment for benign prostatic hypertrophy. The aim of this study was to evaluate the effect on male semen parameters. METHODS: Between July 2014 and January 2022, 20 young men with urinary symptoms of BPH, unresponsive to drug treatment and motivated to preserve ejaculation for eventual paternity, underwent UroLift. Semen analysis was performed before and 6 month after surgery with evaluation of pH, volume, sperm concentration, total motility, vitality and morphology according to WHO 2011. All underwent digital rectal examination, transrectal prostate ultrasound to measure prostate volume, PSA, uroflowmetry, cystoscopy and urodynamics test if necessary. Objective and subjective urinary function was scheduled at 1, 3, 6, 12 month than yearly with UFM, IPSS, IIEF-5, and MSHQ-EjD-SF. RESULTS: At a mean follow-up of 36 month (range 12 to 63), no retroejaculation or changes in seminal parameters occurred. Mean age was 44.5 (range 36.5 to 48) years. Mean operative time was 15 (range 10 to 20) min and 2.5 (range 2 to 4) implants per patients were used. At 6 month there were no difference in terms of total sperm count, volume, pH, motility, vitality, morphology, liquefaction, leucocytes (p = 0.9; p = 0.8; p = 0.7; p = 1; p = 1; p = 1; p = 0,2; p = 0.5). At last, Q-max increased by 64.4% (p = 0.001), post-void residual volume decreased by 66.6% (p = 0.016), and IPSS decreased by 60% (p < 0.001). IIEF and MSHQ-EjD-SF were preserved (p = 0.14, p = 0.4). CONCLUSIONS: UroLift appears safe technique to correct LUTS from BPH in young men desirous to preserve seminal analysis.

Monopolar versus bipolar transurethral resection of bladder Tumour: post-hoc analysis of a prospective trial.

INTRODUCTION: Previously, in a randomised trial we demonstrated bipolar transurethral resection of bladder tumor (TURBT) could achieve a higher detrusor sampling rate than monopolar TURBT. We hereby report the long-term oncological outcomes following study intervention. METHODS: This is a post-hoc analysis of a randomized phase III trial comparing monopolar and bipolar TURBT. Only patients with pathology of non-muscle invasive bladder cancer (NMIBC) were included in the analysis. Per-patient analysis was performed. Primary outcome was recurrence-free survival (RFS). Secondary outcomes included progression-free survival (PFS), cancer-specific survival (CSS) and overall survival (OS). RESULTS: From the initial trial, 160 cases were randomised to receive monopolar or bipolar TURBT. 24 cases of non-urothelial carcinoma, 22 cases of muscle-invasive bladder cancer, and 9 cases of recurrences were excluded. A total of 97 patients were included in the analysis, with 46 in the monopolar and 51 in the bipolar group. The median follow-up was 97.1 months. Loss-to-follow-up rate was 7.2%. Regarding the primary outcome of RFS, there was no significant difference (HR = 0.731; 95%CI = 0.433-1.236; P = 0.242) between the two groups. PFS (HR = 1.014; 95%CI = 0.511-2.012; P = 0.969), CSS (HR = 0.718; 95%CI = 0.219-2.352; P = 0.584) and OS (HR = 1.135; 95%CI = 0.564-2.283; P = 0.722) were also similar between the two groups. Multifocal tumours were the only factor that was associated with worse RFS. CONCLUSION: Despite the superiority in detrusor sampling rate, bipolar TURBT was unable to confer long-term oncological benefits over monopolar TURBT.

Impact of contrast agents on organ dosimetry in pediatric diagnostic fluoroscopy: the voiding cystourethrogram.

Objective.International Commission on Radiological Protection (ICRP) Task Group 113 is developing reference values of organ and effective dose coefficients (DCs) for radiography, fluoroscopy, and computed tomography imaging exams. In support of these efforts, our focus is on pediatric diagnostic fluoroscopy. Contrast agents used during clinical examinations are an important consideration of the work undertaken by the Task Group. This work demonstrates the importance of including organ contrast volume concentrations for the calculation of reference organ DCs in the voiding cystourethrogram (VCUG).Approach.The ICRP newborn and 15 year female reference phantoms were utilized within the Particle and Heavy Ion Transport code system for the calculation of organ DCs. A pediatric radiologist with over 30 years of clinical experience defined the imaging fields for a VCUG examination consistent with clinical practice. Of these, four imaging fields were selected for investigation. The transport simulations modeled an iodinated contrast solution similar to Bracco Group's 18% weight per volume, cystografin diatrizoate meglumine and typical bladder content was supplemented to make up the remainder volume. Iodinated contrast volumes of 0%, 25%, 50%, 75%, and 100% concentration by volume were modeled and associated DCs for in-field organs were computed.Main results.Organ DCs were calculated for the urinary bladder wall, colon wall, ovaries, and uterus for both female phantoms under irradiation geometries representative of a VCUG examination. Some organ DCs increased with iodine volume in the bladder and other organ DCs decreased as the iodine contrast volume completely filled the bladder (100%).Significance.The study results demonstrate for the newborn phantom percent differences in organ DCs varied between 0%-10% for the organs of interest, while they varied between 0%-22% in the 15 year phantom suggesting the importance of including contrast media in Monte Carlo radiation transport simulations of the VCUG examination.

A novel technique for atraumatic transurethral catheterisation of male rats.

Transurethral catheterisation of male rats is technically difficult owing to anatomical peculiarities. In the male rat, the urethral striated sphincter consists of two lateral fascicles separated by an anterior and a posterior strip of connective tissue, which impedes the smooth insertion of a urinary catheter. For rat studies requiring continuous collection of urine, bladder irrigation, or measurement of bladder pressure, investigators either have to exclude the male population (be limited to the female population) or perform percutaneous (suprapubic) bladder puncture in male rats, which is more traumatic and invasive than transurethral catheterisation. This paper describes a novel, atraumatic method of transurethral catheterisation in the male rat, with the aid of a microscope and microsurgical instruments. Six Wistar rats were used for this experiment, all of which were catheterised successfully, with no evidence of bladder or urethral injury. The study shows that male rats can be safely catheterised via the urethra with the aid of a microscope and microsurgical instruments for both visual and tactile feedback. This is a relatively straightforward technique to learn and can allow for inclusion of male rats in future studies requiring urinary analysis or bladder irrigation, without the need for traumatic percutaneous (suprapubic) bladder puncture.