Urethral Morphology Research Articles

The role of ultrasound combined with water bath in the establishment of animal models of rat urethral stricture

Urinary tract injuries represent a significant clinical challenge, necessitating precise diagnosis and effective treatment strategies. Rat models are preferred for studying urinary tract injuries due to their size, visibility of external genitalia, and robust reproductive and growth capabilities. However, there is a lack of standardized methodologies for evaluating the endpoints of rat urinary tract injury models. This study aimed to investigate the methodology of model establishment, imaging evaluation techniques, and endpoint effectiveness. Twenty-four male Sprague-Dawley rats were randomly assigned to groups, including a blank control group and surgical groups. The surgical groups underwent urethral injury induced by recombinant transforming growth factor-β1 (TGF-β1) solution, followed by the random selection of one surgical group (n = 6) to receive treatment with mesenchymal stem cell (MSC) exosomes. High-frequency ultrasonography using a GE E10 device combined with a water bath method was employed to evaluate the urethral conditions of all rats. Ultrasonographic characteristics were scored for all surgical group rats, and an intergroup analysis was conducted between the surgical group and the control group rats. Statistical analysis was conducted using SPSS 22.0 software. Ultrasonographic assessment revealed significant differences in urethral echogenicity between the normal group and the surgical group, with noticeable changes in urethral morphology post-injury. Histopathological examination confirmed more severe urethral stenosis in the TGF group compared to the MSC group. High-frequency ultrasound could effectively differentiate between the two groups of rats. Additionally, there were significant differences in the scoring of ultrasonographic characteristics between the two groups. Urethral stricture presents a complex challenge in urology, often requiring invasive treatment modalities. The establishment of animal models plays a crucial role in understanding and addressing this condition. TGF-β1 induced fibrosis and MSC therapy represent promising avenues for urethral stricture management. High-frequency ultrasound combined with the immersion method offers a non-invasive and cost-effective approach for evaluating rat urethral stricture models. This study highlights the practicality of high-frequency ultrasound combined with the water bath method in evaluating rat urethral stricture models, as it can effectively differentiate between rats in the pure TGF-β1 induced group and those in the MSC treatment group based on urethral changes. The results underscore the importance of standardized methodologies for model assessment and the potential of non-invasive imaging techniques in preclinical research. Overall, this study contributes to advancing our understanding of urinary system injuries and holds implications for future therapeutic interventions in urology.

External validation and reliability assessment of posterior urethral morphology on initial voiding cystourethrogram as a predictor for infants with posterior urethral valves

The morphology of the bladder and posterior urethra on initial voiding cystourethrogram (VCUG) in posterior urethral valve (PUV) has been proposed as a meaningful early metric for short- and long-term kidney outcomes. Here, we seek to externally validate the proposed association and assess the reliability of PUV morphology characteristics. We reviewed our institutional database for patients managed for PUV between 2000 and 2022 and included those treated with primary ablation with at least 1 year of follow-up for kidney function. Each VCUG was evaluated by three independent raters for the height-width ratio of the bladder (HW-B), height-width ratio of the posterior urethra (HW-PU), and posterior-anterior urethral ratio (PA-UR), and trabeculation (none, fine, or coarse). We assessed the reliability in these with intra-class coefficient and Fleiss kappa for continuous and categorical data, respectively. We performed univariate analysis with nadir creatinine and five-year follow-up glomerular filtration rate (GFR). In total, 98 patients met inclusion criteria. The median age at diagnosis and ablation was 10 and 21 days, respectively. Patients with nadir creatinine <0.8mg/dL had higher follow-up GFR (101 vs. 20ml/min/1.73m2, p=0.04), and lower risk of CKD (odds ratio 14.7, p=0.002). The median value for HW-B was 1.4, median HW-PU was 2.1, and median PA-U was 4.7, There was significant inter-class agreement between all three measures of 0.80, 0.51, and 0.70 (p<0.001). The inter-rater agreement for bladder trabeculation was fair (Fleiss K=0.40, p<0.001). There was no statistically significant correlation between HW-B, HW-PU, PU-A with nadir creatinine (p=0.07, 0.33, 0.91) or 5-year GFR (0.27, 0.45, 0.62), respectively. There is significant interest in determining prognostic factors and metrics in PUV. The morphological characteristics on VCUG are reliable and is available information for all boys diagnosed with PUV, resulting in an attractive metric. While we do not demonstrate correlation with kidney outcomes, VCUG features warrant further attention as prognostic factors in PUV. PUV morphology on initial VCUG is a reliable metric of lower urinary tract deformity but is not associated with 5-year kidney outcomes.

Dynamic simulation and analysis of the influence of urethral morphological changes on urodynamics after benign prostatic hyperplasia surgery: A computational fluid dynamics study

Background and objectiveComputational fluid dynamics (CFD) technology has been widely used in medicine to simulate and analyse urine flow characteristics in urology. In previous studies, researchers have modelled the analysis with a simple circular urethra, ignoring the effect of the patient's true urethral morphology on the urinary flow rate. Moreover, the studies tended to be steady-state simulations rather than dynamic simulations. Therefore, this study is established a relatively realistic model of the posterior urethra based on MRI data combined with the urodynamic data of patients and analysed the urodynamic characteristics of the posterior urethra model after benign prostatic hyperplasia (BPH) surgery using a CFD dynamic simulation. MethodsBased on clinical MRI data, a three-dimensional real urethral model was established for two patients with BPH after surgery. The boundary conditions were set according to the patients’ real urodynamic data, and a Reynolds averaged Navier‒Stokes model was used for transient simulations. The dynamic simulation depicted the entire urination process, and the urine flow characteristics were studied under real urethral morphology after surgery. Results1. By comparing the three-dimensional trajectory of urine and the vortex identification cloud map based on the Q criterion, we intuitively observed the distribution of the vortex in the model, and a ‘gourd-shaped’ urethra was more likely to generate a vortex than a ‘funnel-shaped’ urethra. 2. After surgery for BPH, the changes in the posterior urethral pressure were mainly concentrated in the urethral membrane, and the velocity increased while the pressure decreased. The curve of the posterior urethral pressure changes during urination was simulated and calculated. The posterior urethral pressure gradients of the two patients were 6.6 cmH2O and 5.26 cmH2O. ConclusionsThe complete urinary discharge process can be dynamically simulated using CFD techniques. By comparing the simulation results, the posterior urethral morphology can have an important impact on the urinary flow characteristics. Determining the location of vortex generation can lay a foundation for personalized surgical plans for patients in the future. Furthermore, numerical simulations can provide a new method for the study of non-invasive posterior urethral pressure gradients.

Editorial comment on “Posterior urethral morphology on initial voiding cystourethrogram correlates to early renal outcomes in infants with posterior urethral valves”

In this interesting paper, the authors have studied the bladder height to width ratio (HW-B), posterior urethral height to width ratio (HW-PU), posterior-anterior urethral ratio (PA-UR) and bladder trabeculation grade on initial voiding cystourethrogram (VCUG) of children with posterior urethral valve (PUV) and found that only HW-PU significantly correlated with a higher nadir creatinine at one-year of age [1]. Niyogi [2] proposed that in children with PUV increasingly distorted bladder shape was associated with poor bladder dynamics and proposed shape, wall, reflux and diverticuli (SWRD) score.

The clinical application of transperineal ultrasound in urogynaecology

Key content Transperineal ultrasound allows reproducible imaging of pelvic floor conditions that aids in the thorough assessment required to diagnose and treat urogynaecological conditions. Views that can be obtained include two‐dimensional (2D) sagittal views of the bladder neck, urethra and pelvic floor; 2D coronal views of the anal canal; and three‐dimensional (3D) or four‐dimensional (4D) views of the genital hiatus and anal canal. This allows assessment of the post‐void residual volumes, detrusor wall thickness and dynamic assessment of the urethral morphology. Ultrasonographic assessment enables accurate information about maternal birth trauma to be ascertained, including levator ani muscle avulsion and obstetric anal sphincter injury. Transperineal ultrasound can be used to identify and assess previously implanted vaginal mesh and midurethral slings. Learning objectives To understand the role of ultrasound in clinical urogynaecology practice, including the assessment of slings and meshes. To know the ultrasound probes, techniques and views used to image the pelvic floor and anal sphincters by transperineal ultrasound. To describe assessment of the lower urinary tract, pelvic organ prolapse and obstetric anal sphincter injury using ultrasound. Ethical issues Thorough assessment of the pelvic floor is mandatory against the background of technological advances in the investigation of pelvic floor dysfunction. As a common and major complication of childbirth, maternal birth trauma must be assessed fully to support primary and secondary prevention. Thorough assessment must underlie the use of mesh implants, and dealing with sling and mesh complications is enhanced by imaging.

Posterior urethral morphology on initial voiding cystourethrogram correlates to early renal outcomes in infants with posterior urethral valves

Posterior urethral valves (PUV) is a leading cause of chronic renal failure in childhood. Bladder and posterior urethral deformity in infants with PUV are highly variable on initial voiding cystourethrogram (VCUG). Some types of deformity may be more important than others in determining the severity of the condition. Identification of specific VCUG features may allow for a simple, early screening assessment for patients. Determine whether morphologic features on the initial VCUG correlate to renal outcomes as measured by the creatinine nadir in the first year after ablation. Children with PUV treated by primary valve ablation before 12 months old and followed >1 year were identified. Initial diagnostic VCUG was evaluated for the bladder height to width ratio (HW-B), posterior urethral height to width ratio (HW-PU), and posterior-anterior urethral ratio (PA-UR). A trabeculation grade was assigned by three pediatric urologists, and reflux was noted. Univariable analyses with chi-square and t-test were used to compare bladder and posterior urethral morphology factors among those who obtained a creatinine nadir <0.8 or ≥0.8mg/dL in the first year after ablation. Linear regression was performed to correlate morphology values with true creatinine nadir. A total of 120 boys were ablated at mean age of 40.5 days (range 0-342) and followed for 5.9 years (± 3.85). Among these, 21 (17.5%) had a creatinine nadir ≥0.8mg/dL. Mean overall HW-B and mean PA-UR were not significantly different between those with creatinine nadir <0.8 versus ≥0.8mg/dL. Bladder trabeculation grade was not associated with creatinine nadir. For the entire cohort, only the difference in HW-PU was statistically significant between creatinine nadir groups with a much higher ratio among those with a nadir ≥0.8 (p<0.001). Linear regression demonstrated a significant positive correlation between the HW-PU and creatinine nadir (R 2=0.097, p=0.002). The presence of bilateral reflux is significantly associated with creatinine nadir ≥0.8mg/dL (p=0.001). We investigate for the first time the association of morphology features on the initial VCUG with renal outcome in PUV patients. Posterior urethral deformity as quantified by a higher HW-PU ratio is significantly correlated with a higher creatinine nadir, whereas measured bladder morphology metrics are not. HW-PU may be an indirect measure of the severity of obstruction in posterior urethral valves. The HW-PU appears to be a meaningful early morphologic metric for renal outcome.

Hypoxia-preconditioned adipose-derived stem cells combined with scaffold promote urethral reconstruction by upregulation of angiogenesis and glycolysis

RationaleTissue engineering is a promising alternative for urethral reconstruction, and adipose-derived stem cells (ADSCs) are widely used as seeding cells. Hypoxia preconditioning can significantly enhance the therapeutic effects of ADSCs. The low oxygen tension of postoperative wound healing is inevitable and may facilitate the nutritional function of ADSCs. This study aimed to investigate if hypoxia-preconditioned ADSCs, compared to normoxia-preconditioned ADSCs, combined with scaffold could better promote urethral reconstruction and exploring the underlying mechanism.MethodsIn vitro, paracrine cytokines and secretomes that were secreted by hypoxia- or normoxia-preconditioned ADSCs were added to cultures of human umbilical vein endothelial cells (HUVECs) to measure their functions. In vivo, hypoxia- or normoxia-preconditioned ADSCs were seeded on a porous nanofibrous scaffold for urethral repair on a defect model in rabbits.ResultsThe in vitro results showed that hypoxia could enhance the secretion of VEGFA by ADSCs, and hypoxia-preconditioned ADSCs could enhance the viability, proliferation, migration, angiogenesis, and glycolysis of HUVECs (p < 0.05). After silencing VEGFA, angiogenesis and glycolysis were significantly inhibited (p < 0.05). The in vivo results showed that compared to normoxia-preconditioned ADSCs, hypoxia-preconditioned ADSCs combined with scaffolds led to a larger urethral lumen diameter, preserved urethral morphology, and enhanced angiogenesis (p < 0.05).ConclusionsHypoxia preconditioning of ADSCs combined with scaffold could better promote urethral reconstruction by upregulating angiogenesis and glycolysis. Hypoxia-preconditioned ADSCs combined with novel scaffold may provide a promising alternative treatment for urethral reconstruction.

Vorticity in lower urinary tract can be assessed and associates with urinary tract morphology in men.

The aim of this study is to develop a method to evaluate the fluid dynamics of urine flow in the lower urinary tract (LUT), especially that of vorticity. This investigation included three sub-studies to demonstrate urine flow in the entire LUT. First, we attempted to observe vorticity generation in the urinary bladder during spontaneous voiding using transabdominal color Doppler ultrasonography (CDUS). Second, we performed transrectal CDUS to evaluate the vorticity of urine flow in the prostatic urethra. Patients with prostate cancer were enrolled before robotic surgery and divided into the vorticity and non-vorticity groups based on CDUS findings for comparisons of longitudinal urethral diameter and prostatic urethral angle. Third, the vorticity of the voided urine stream was observed using a high-speed video-camera. Micturition was done in a standing position while synchronously monitored for urine flow using uroflowmetry. Vorticity formation could be dynamically demonstrated in the urinary bladder and prostatic urethra using CDUS. The prostatic urethral angle of the vorticity group was more than that of the non-vorticity group. High-speed video recording could clearly capture vorticity and spiral shape generation in voided urine. The distance from the external urethral orifice to the first twist changed in accordance with urine flow rate. In a series of sub-studies, this investigation proved vorticity generation in the LUT and voided urine. Vorticity was detectable in the LUT and in voided urine using CDUS and a high-speed video-camera. Vorticity generation might be associated with urethral morphology.

Morphological and clinical evaluation of prostatic urethra using modified sonourethrography with retrograde jelly injection.

Using modified sonourethrography (mSUG) with retrograde jelly injection to precisely measure the morphological characteristics of the prostatic urethra, we assessed prostatic urethral morphology associated with clinical parameters of benign prostatic hyperplasia (BPH). BPH patients (n = 43) and control patients with localized prostate cancer (PC; n = 57) were imaged by mSUG before surgery. Using the seminal colliculus as a landmark, prostatic urethral angulation (PUA), sagittal urethral diameter, and anterior or posterior prostatic urethral length were measured. The International Prostatic Symptoms Score (IPSS) was also evaluated in all patients. The Bladder Outlet Obstruction Index (BOOI) was measured in BPH patients that could void in a pressure-flow study. Parameters were compared between BPH and PC patients, and correlations among morphological and clinical parameters were evaluated. Prostatic urethras were clearly observed in all patients by mSUG. PUA, sagittal urethral diameter, and posterior urethral length were all greater in BPH than PC patients (P < .05). Among all parameters examined, PUA had the strongest correlation with IPSS (r = 0.56). Longitudinal urethral diameter showed the strongest correlation with BOOI, whereas PUA was not correlated with BOOI. Prostatic urethral morphology can be imaged precisely by mSUG. Morphometric measurements showed that increased PUA was strongly correlated with problematic urinary symptoms, and a flattened shape of the posterior urethra, such as extension of the sagittal urethral diameter, was correlated with urinary tract obstruction by BPH.

MP42-08 MALE URETHRAL SPHINCTER COMPLEX REVISITED USING NOVEL MR IMAGING TECHNIQUES

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology I1 Apr 2017MP42-08 MALE URETHRAL SPHINCTER COMPLEX REVISITED USING NOVEL MR IMAGING TECHNIQUES Kyoko Sakamoto, Valmik Bhargava, Vadim Malis, M. Raj Rajasekaran, and Shantanu Sinha Kyoko SakamotoKyoko Sakamoto More articles by this author , Valmik BhargavaValmik Bhargava More articles by this author , Vadim MalisVadim Malis More articles by this author , M. Raj RajasekaranM. Raj Rajasekaran More articles by this author , and Shantanu SinhaShantanu Sinha More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1297AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Anatomical description of the male urethral sphincter complex (internal lissospincter and external rhabdosphincter) has undergone several revisions as previous conclusions were mostly derived from gross cadaveric dissection of adult male pelvis. These findings have been plagued by distortions of the anatomical structures in cadavers. Our objective was to elucidate the anatomy of the urethral sphincter muscles by resorting to in vivo, non-invasive imaging, using proton-density (PD), diffusion tensor imaging (DTI) and fiber tracking and thereby improve our understanding by avoiding the errors in cadaveric studies. METHODS Normal healthy five male young subjects, (mean age ~25 yrs) were scanned on a 3T GE MR scanner, using a multi-channel cardiac coil, lying supine, feet-first. After acquisition of a high resolution sagittal scout scan (Fig. A), axial morphological proton-density scans were prescribed and acquired extending from a few slices below the base of the bladder to beyond the entry of the urethra into the penis (~18-22 slices depending on the height of the subject). Three mm thick DTI scans were acquired and analyzed to obtain first the tensor axial images (Fig. B-C) to construct fibers within this urethral complex. RESULTS A consistent finding was that of possibly two sphincter like muscles (Fig. D-E), with one proximal near the bladder neck (yellow arrow in Fig. A, B) and the other more distal (Fig. C). In the tensor images, blue color indicates fibers oriented superior- inferior, red left-right while green anterior-posterior directions. Fiber tracking of these tensor images yields fiber structures within the urethral sphincter complex. The proximal sphincter is shown in Fig. D, the distal sphincter in Fig. E. The connecting superior-inferior longitudinal fibers are shown in blue in Fig. F. A consistent finding was the distance between the two sphincters is between 21 and 24 mm (i.e., 7 to 8 slices). CONCLUSIONS This is perhaps the first DTI and fiber tracking of the male urethral sphincter complex. Our findings support the two sphincter concept to constrict/close the urethral opening. These observations will form the basis of normal urethral morphology that can be monitored in post-surgery patients and correlated with age /urinary incontinence symptoms. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e546-e547 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Kyoko Sakamoto More articles by this author Valmik Bhargava More articles by this author Vadim Malis More articles by this author M. Raj Rajasekaran More articles by this author Shantanu Sinha More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The changes of urethral morphology recognized in voiding cystourethrography after endoscopic transurethral incision for posterior urethral valve in boys with intractable daytime urinary incontinence and nocturnal enuresis.

Endoscopic transurethral incision (TUI) of posterior urethral valve (PUV) can improve daytime urinary incontinence (DUI) and nocturnal enuresis (NE). However, the underlying mechanism has not been elucidated. In this study, we retrospectively examined the mobility of the urethra before and after TUI by measuring the urethral angle with voiding cystourethrography (VCUG), to clarify the effects of TUI on the morphology of the urethra during voiding. Between July 2010 and December 2014, 29 boys with intractable DUI and/or NE were diagnosed as PUV and underwent endoscopic TUI. VCUG during voiding phase was performed at sequential radiographic spot images (1 image per second) at a 45° angle in oblique standing position. The point at which the angle of the urethra was the smallest during urination was regarded as the minimum urethral angle. The maximum urethral angle during early voiding phase was compared with the minimum urethral angle, and the percentage by which this angle changed was calculated as the flexion rate. Then changes in minimum urethral angle and flexion rate were analyzed before and 3-4 months after TUI. After TUI, the minimum urethral angle on VCUG became more obtuse (before vs. after TUI, respectively: 112.7 vs. 124.5°, p < 0.001), the flexion rate decreased (before vs. after TUI, respectively: 11.8 vs. 4.1%, p < 0.001). This study demonstrated a significant difference in the degree of change. The findings may contribute to understanding of the mechanism of improvement in symptoms after TUI in patients with PUV.

Electrospun Poly(l-lactide)/Poly(ethylene glycol) Scaffolds Seeded with Human Amniotic Mesenchymal Stem Cells for Urethral Epithelium Repair.

Tissue engineering-based urethral replacement holds potential for repairing large segmental urethral defects, which remains a great challenge at present. This study aims to explore the potential of combining biodegradable poly(l-lactide) (PLLA)/poly(ethylene glycol) (PEG) scaffolds and human amniotic mesenchymal cells (hAMSCs) for repairing urethral defects. PLLA/PEG fibrous scaffolds with various PEG fractions were fabricated via electrospinning. The scaffolds were then seeded with hAMSCs prior to implantation in New Zealand male rabbits that had 2.0 cm-long defects in the urethras. The rabbits were randomly divided into three groups. In group A, hAMSCs were grown on PLLA/PEG scaffolds for two days and then implanted to the urethral defects. In group B, only the PLLA/PEG scaffolds were used to rebuild the rabbit urethral defect. In group C, the urethral defect was reconstructed using a regular urethral reparation technique. The repair efficacy was compared among the three groups by examining the urethral morphology, tissue reconstruction, luminal patency, and complication incidence (including calculus formation, urinary fistula, and urethral stricture) using histological evaluation and urethral radiography methods. Findings from this study indicate that hAMSCs-loaded PLLA/PEG scaffolds resulted in the best urethral defect repair in rabbits, which predicts the promising application of a tissue engineering approach for urethral repair.

Pelvic floor muscle training in women with stress urinary incontinence causes hypertrophy of the urethral sphincters and reduces bladder neck mobility during coughing

The purpose of this study was to determine the effect of a 12-week pelvic floor muscle (PFM) training program on urethral morphology and mobility in women with stress urinary incontinence (SUI). Forty women with SUI were randomly assigned to one of two groups: the treatment group received 12 weekly physiotherapy sessions during which they learned how to properly contract their pelvic floor muscles (PFMs) and a home exercise program was prescribed, reviewed, and progressed; the control group received no treatment. Before and after the 12-week study period, ultrasound imaging was used to evaluate bladder neck position and mobility during coughing and Valsalva maneuver in supine and in standing, as well as urethral morphology. Secondary outcome measures included a 3-day bladder diary, 30-min pad test, the Incontinence Impact Questionnaire (IIQ-7) and the Urogenital Distress Inventory (UDI-6). The women in the treatment group demonstrated reduced bladder neck mobility during coughing and increased cross-sectional area of their urethra after as compared to before the training. These changes were not evident in the control group. No differences in the resting position of the bladder neck or in bladder neck excursion during Valsalva maneuver were noted in either group. Concomitantly the women in the treatment group demonstrated significant improvements in the 3-day bladder diary and IIQ-7 after the PFM training and improved significantly more than the control group. Physiotherapist-supervised PFM training reduces bladder neck motion during coughing, and results in hypertrophy of the urethral sphincter in women who present with SUI.

OC10.05: Parity and urethral mobility and morphology measured by ultrasound

OC10.05: Parity and urethral mobility and morphology measured by ultrasound

Normal Kadın Üretrasının Radyografik Varyasyonları: Voiding Sistoüretrografi ile Klasifikasyon

Objective: Female urethra can be visualized in different anatomical shapes during voiding cystourethrography.We presented the different types of urethral shapes which we encountered and to correlate our larger series with literature. Materials and methods: The VCU examinations of pediatric patients for the investigation of mainly vesicoureteral reflux or other urinary system pathologies mostly referred with the prediagnosis of urinary tract infections and enuresis nocturna were retrospectively evaluated. 381 patients without any micturation symptoms and with normal urethral meatus underwent 426 vesicoureteral reflux examinations. The shapes of urethra were described and then classified according to the sort of shapes appeared during vesicoureteral reflux examination. Results: We identified six different types of urethral morphology. The most common configuration in our study was cylindirical shaped urethra (n=170) (44%). These were subclassified as thick (n=38) (9.9%), thin (n=25) (6.5%), long (n=65) (17%) and short (n=42) (11%). Others were goblet (n=69) (19%), fusiform (n=66) (17%), spinning top (n=44) (12%), wedge (n=27) (7%), and beaded (n=5) (1%) shaped urethras. Conclusion: During the vesicoureteral reflux procedure female urethra can be visualised in diverse shapes. Radiologist and pediatricians must become familiar to the normal anatomical shapes of female urethra for not to interpret it as pathological.

Three-dimensional ultrasonographic assessment of compression effect on urethra following tension-free vaginal tape and transobturator tape procedures

To compare the anatomical difference using three-dimensional (3D) ultrasound between the urethra at rest and during straining, in women who have undergone a tension-free vaginal tape (TVT) or TVT-obturator tape (TVT-O) procedure for stress urinary incontinence (SUI). We reviewed retrospectively 48 women with SUI who had undergone either a TVT (n = 24) or a TVT-O (n = 24) procedure. All women underwent urinalysis, pelvic examination, pad test, 3D perineal ultrasonography and personal interview about urinary symptoms within 1 year after surgery. After both TVT and TVT-O procedures, the area and longest and shortest diameters of the hypoechoic core of the mid-urethra were significantly smaller during straining than during resting (P < 0.01). The distance between tape and urethra was similarly smaller during straining in both groups. Analysis of ultrasound measurements in women reporting success (n = 40) and those reporting failure (n = 8) of the procedure showed the area and longest and shortest diameters of the hypoechoic core of the mid-urethra to be significantly smaller during straining than during resting in both groups (P < 0.01). However, the shortest diameter of the proximal and distal urethra during straining were significantly smaller only in the successful group (P < 0.01). There are differences in urethral morphology during straining compared with during resting in women with TVT and those with TVT-O, regardless of tape procedure. A urethral compression effect of slings may have an important role in the continence mechanism.

Development of a rabbit's urethral sphincter deficiency animal model for anatomical-functional evaluation

The aim of the study was to develop a new durable animal model (using rabbits) for anatomical-functional evaluation of urethral sphincter deficiency. A total of 40 New Zealand male rabbits, weighting 2.500 kg to 3.100 kg, were evaluated to develop an incontinent animal model. Thirty-two animals underwent urethrolysis and 8 animals received sham operation. Before and at 2, 4, 8 and 12 weeks after urethrolysis or sham operation, it was performed cystometry and leak point pressure (LPP) evaluation with different bladder distension volumes (10, 20, 30 mL). In each time point, 10 animals (8 from the study group and 2 from the sham group) were sacrificed to harvest the bladder and urethra. The samples were evaluated by H&E and Masson 's Trichrome to determine urethral morphology and collagen/smooth muscle density. Twelve weeks after urethrolysis, it was observed a significant decrease in LPP regardless the bladder volume (from 33.7 ± 6.6 to 12.8 ± 2.2 cmH₂O). The histological analysis evidenced a decrease of 22% in smooth muscle density with a proportional increase in the collagen, vessels and elastin density (p < 0.01). Transabdominal urethrolysis develops urethral sphincter insufficiency in rabbits, with significant decrease in LPP associated with decrease of smooth muscle fibers and increase of collagen density. This animal model can be used to test autologous cell therapy for stress urinary incontinence treatment.

下部尿路閉塞の3次元モデルの作成と仮想内視鏡画像による診断法の有効性の検討

I observed bladder and urethral morphology and lumen by making a virtual endoscopy (VE) of the bladder and a urethra for patients with lower urinary tract symptoms. I have herein reported the procedures to use this model to evaluate the condition of patients more precisely. Of those referred for investigation of lower urinary tract symptoms, subjects were 22 boys (5-13 years old, mean 9) in whom voiding cystourethrography (VCUG) was suspected for urethral obstruction between March, 2009 and October, 2010. Eleven of these 22 cases were extracted at random and underwent voiding computed tomography (VCT). Except one dropped out, the 21 cases were assigned to a VCT/VCUG combination group or a VCUG-single group. We confirmed the two groups, the rate of agreement of imaging views and cystourethroscopy (CS) views, and the effectiveness of endoscopic operation. I made the following imaging diagnoses in the VCT/VCUG combination group: congenital obstructive posterior urethral membrane (COPUM), n = 7; Cobb's collar, n = 1; and COPUM and Cobb's collar combined, n = 3. In contrast, in the VCUG-single group, I diagnosed COPUM, n = 5; bulbar region urethral stricture, n = 2; posterior urethral expansion, n = 2; and bladder form abnormality, n = 1. The rate of agreement between preoperative diagnosis and CS views on imaging was 72.7% in the VCT/VCUG combination group, and 33.3% in the VCUG-single group. All patients underwent transurethral incision (TUI) of the urethral obstruction. In the VCT/VCUG combination group, effectiveness of the TUI was assessed as good in 2 cases and moderate in 6 cases giving an overall effectiveness rate (good + moderate) of 72.7%. In the VCUG-single group, effectiveness was rated as moderate in 5 cases (overall effectiveness rate = 50%). I developed a method of VE for lower urinary tract obstruction of children and examined the effectiveness. This method was found to be more effective than conventional urinary tract imaging. With the developments in the equipment, this method may in future be useful as an adjunct to CS and urodynamic studies.

Racial differences in female urethral morphology and levator hiatal dimensions: An ultrasound study

To compare the urethral sphincter morphology and levator hiatal dimensions between white and black premenopausal nulliparous asymptomatic women using 3D/4D translabial ultrasonography. Nulliparous black and white women were recruited in a tertiary gynecological center. All women were completely asymptomatic for pelvic floor dysfunction. Women were assessed with 3D/4D translabial ultrasound scan of the pelvic floor, at rest. Measurements of the total urethral sphincter volume (TSV), rhabdosphincter volume, (RSV) and levator hiatal dimensions (LH) were taken at rest, after voiding. Twenty-three white and 14 black women (37 in total) were investigated. Subjects did not differ by age or body mass index (BMI). Black women were found to have significantly larger rhabdosphincters (RS) than their white counterparts (8.88 cm(3) ± 1.65 vs. 5.97 cm(3) ± 1.82, respectively, P = 0.000). With respect to levator hiatal dimensions at rest, black women had a significantly wider transverse diameter (LHt) than white women (mean difference of LHt = 0.43 cm, 95% CI 0.08-0.78, P < 0.05). Asymptomatic black nulliparous women have significantly larger rhabdosphincters than their white counterparts. Racial differences in the female urethral morphology could provide an insight on the pathophysiology of stress urinary incontinence.

The effect of solifenacin on urethral sphincter morphology

The aim of the study was to determine whether a 6-week course of 5 mg of solifenacin succinate used to treat mixed incontinence, produces measurable changes in the appearance of the urethral sphincter. Twenty-six women undergoing treatment for mixed incontinence were recruited from a urogynaecology unit after failing to improve with conservative treatments and bladder drill. All underwent dual channel subtracted cystometry, which showed mixed urodynamic stress incontinence and detrusor overactivity. All patients underwent a 3D transperineal ultrasound before solifenacin therapy was started and after 6 weeks of treatment. The urethral length, width and volume of the smooth muscle and total sphincter volume were compared before and after the treatment. Clinically, 13 reported no improvement in either stress or urge incontinence. Eight women reported improvement in their urgency symptoms but no benefit in their stress leakage. Four women reported resolution of both stress and urge incontinence. One woman reported worsening of her bladder symptoms. There was no significant change in the urethral length (p = 0.27), width (p = 0.50), volume of smooth muscle (p = 0.87) or total sphincter volume (p = 0.60) before and after treatment with solifenacin. A 6-week course of solifenacin resulted in no measurable changes in the appearance of the urethral sphincter.