Review of the effect of 3D medical printing and virtual reality on urology training with ‘MedTRain3DModsim’ Erasmus + European Union Project

Background/aim

It is necessary to incorporate novel training modalities in medical education, especially in surgical fields, because of the limitations of cadaveric training. Traditional medical education has many drawbacks, such as residency working hour restrictions, patient safety conflicts with the learning needs, and the lack of hands-on workshops. The MedTRain3DModsim Project aimed to produce 3-dimensional (3D) medical printed models, simulations, and innovative applications for every level of medical training using novel worldwide technologies. It was aimed herein to improve the interdisciplinary and transnational approaches, and accumulate existing experience for medical education, postgraduate studies, and specialty training.

Materials and methods

This project focused on models of solid organs and the urinary system, including the kidney, prostate, ureter, and liver. With 3D medical printing, it is possible to produce a body part from inert materials in just a few hours with the standardization of medical 3D modeling.

Results

The target groups of this project included medical students and residents, graduate students from engineering departments who needed medical education and surgical training, and medical researchers interested in health technology or clinical and surgical an atomy.

Conclusion

It was also intended to develop a novel imaging platform for education and training by reevaluating the existing data using new software and 3D modalities. Therefore, it was believed that our methodology could be implemented in all related medical fields.

Prostate enlargement and altered urinary function are part of the aging process

Prostate disease incidence, both benign and malignant, directly correlates with age. Men under 40 years of age are rarely diagnosed with benign or malignant prostate disease, while 90% of men over the age of 80 have histological evidence of benign disease (benign prostatic hyperplasia; BPH). Although rodent models have been invaluable in the study of disease progression and treatment efficacy, the effect of age is often not considered. In examining aged (24-month-old) mice, we observed changes within the lower urinary tract that is typically associated with lower urinary tract dysfunction (LUTD) similar to models of BPH. In this study, we identify LUTD using functional testing as well as various imaging technologies. We also characterize the histological differences within the lower urinary tract between young (2-month-old) and aged mice including proliferation, stromal remodeling, and collagen deposition. Additionally, we examined serum steroid hormone levels, as steroid changes drive LUTD in mice and are known to change with age. We conclude that, with age, changes in prostate function, consistent with LUTD, are a consequence. Therapeutic targeting of endocrine and prostatic factors including smooth muscle function, prostate growth and fibrosis are likely to reestablish normal urinary function.

Fluoroscopic Evaluation of Adult Male Urethral Abnormalities

Retrograde urethrograms and voiding cystourethrograms provide clinicians with important information to determine treatment options and surgical interventions for patients with urethral abnormalities. This article discusses the elements with which radiologic technologists should be familiar, including urethra anatomy, the pathology of urethral abnormalities, imaging techniques, and special considerations for preoperative and postoperative patients.

Novel Card Games for Learning Radiographic Image Quality and Urologic Imaging in Veterinary Medicine

Second-year veterinary students are often challenged by concepts in veterinary radiology, including the fundamentals of image quality and generation of differential lists. Four card games were developed to provide veterinary students with a supplemental means of learning about radiographic image quality and differential diagnoses in urogenital imaging. Students played these games and completed assessments of their subject knowledge before and after playing. The hypothesis was that playing each game would improve students' understanding of the topic area. For each game, students who played the game performed better on the post-test than students who did not play that game (all p<.01). For three of the four games, students who played each respective game demonstrated significant improvement in scores between the pre-test and the post-test (p<.002). The majority of students expressed that the games were both helpful and enjoyable. Educationally focused games can help students learn classroom and laboratory material. However, game design is important, as the game using the most passive learning process also demonstrated the weakest results. In addition, based on participants' comments, the games were very useful in improving student engagement in the learning process. Thus, use of games in the classroom and laboratory setting seems to benefit the learning process.

Anatomy and physiology of the lower urinary tract

Functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. Neural control of micturition is organized as a hierarchic system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brainstem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brainstem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily during the early postnatal period, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults cause re-emergence of involuntary micturition, leading to urinary incontinence. The mechanisms underlying these pathologic changes are discussed.

Anatomy and Physiology of the Urinary Tract: Relation to Host Defense and Microbial Infection

The urinary tract exits to a body surface area that is densely populated by a wide range of microbes. Yet, under most normal circumstances, it is typically considered sterile, i.e., devoid of microbes, a stark contrast to the gastrointestinal and upper respiratory tracts where many commensal and pathogenic microbes call home. Not surprisingly, infection of the urinary tract over a healthy person's lifetime is relatively infrequent, occurring once or twice or not at all for most people. For those who do experience an initial infection, the great majority (70% to 80%) thankfully do not go on to suffer from multiple episodes. This is a far cry from the upper respiratory tract infections, which can afflict an otherwise healthy individual countless times. The fact that urinary tract infections are hard to elicit in experimental animals except with inoculum 3-5 orders of magnitude greater than the colony counts that define an acute urinary infection in humans (105 cfu/ml), also speaks to the robustness of the urinary tract defense. How can the urinary tract be so effective in fending off harmful microbes despite its orifice in a close vicinity to that of the microbe-laden gastrointestinal tract? While a complete picture is still evolving, the general consensus is that the anatomical and physiological integrity of the urinary tract is of paramount importance in maintaining a healthy urinary tract. When this integrity is breached, however, the urinary tract can be at a heightened risk or even recurrent episodes of microbial infections. In fact, recurrent urinary tract infections are a significant cause of morbidity and time lost from work and a major challenge to manage clinically. Additionally, infections of the upper urinary tract often require hospitalization and prolonged antibiotic therapy. In this chapter, we provide an overview of the basic anatomy and physiology of the urinary tract with an emphasis on their specific roles in host defense. We also highlight the important structural and functional abnormalities that predispose the urinary tract to microbial infections.

The anatomical knowledge of Joaquín Albarrán (1860-1912)

Joaquín Maria Albarrán (1860-1912) is broadly known as a brilliant mind and a pioneer of modern urology, in spite of his short life. Born in Cuba and being early an orphan, he was sent to Barcelona to study Medicine. Graduate at the age of seventeen, he continued his studies in Paris, where he was trained in surgery and urology, and spent the rest of his life having an extraordinary career as urology surgeon, chief of the Urology Department in Necker Hospital and professor at Paris Faculty of Medicine. Since his first studies, he had been passionate with anatomy, histology, pathology and microbiology and embodied in his books, today considered as classics, a great amount of the special knowledge he had for these fields and the most accurate descriptions of the operative techniques for the urinary tract system.

A study of the surgical scenario in endourology. The Campos instrument

OBJECTIVES

A new concept for endoscopy is presented in the form of a ureteroscope and cystoscope that efficiently adapts to the needs and situation of the surgical scenario, both in patient's health benefit and better results, and also physician's wellbeing.

METHODS

The concept of the instrument, in the neutral position, gives response to the urinary tract anatomy in supine decubitus: horizontally form side to side. The instrument has a handle with a rotor to control the distal active flexible segment of the shaft. It has a unique new shaft with at least three different elastic properties with a proximal firm first segment, followed by a second passive flexible and a third distal active flexible segment. Two pending US patents and another patent endorse the invention.

RESULTS

A perceptive instrument from first contact has been developed. The horizontal response reduces rotation requirements, X-ray needs down to 30 seconds at the most, and operating time to a third. It may be introduced and maneuvered with one hand only, avoiding the need for an assistant and it has the ad vantage that it may be used sitting.

CONCLUSIONS

Current operating room scenario generates a demanding situation, affecting even surgeon's own general health. The Campos Instrument has exclusive features for operating room ergonomic fusion, making procedures more dynamic. It simulta-neously procures patient and physician's health. Allows a predictable navigation and provides the stability of a firm endoscope with the diagnostic and therapeutic capabilities of the flexible.

Children's concepts of the urinary tract

OBJECTIVE

To assess children's body concepts about anatomy and physiology of the urinary tract, children drew pictures responding to the question 'Where do you believe urine comes from?'

SUBJECTS AND METHODS

A total of 152 children in three groups were examined. 81 children were out-patients. Of these, 36 children were being seen for the first time and 45 children had previously undergone bladder and bowel group training. They were compared to 71 continent controls. Children were given a body silhouette, in which they drew their view of the urinary tract.

RESULTS

Half of the children (52.6%) drew a bladder and other organs; nearly 43% drew a tube or other anatomically incorrect pictures. Significant differences were found for group and age. Children who had undergone the group training more often drew a bladder and other organs (80%). Correct pictures and pictures of bladder and other organs were more common from children aged 11-16 years.

CONCLUSION

Children have subjective concepts of the urinary tract which do not follow actual anatomy and physiology. For medical interventions as well as any training programmes, it is essential to understand these concepts and provide instructions in a child-centred and developmentally adequate way.

Urinary catheterization of male rabbits: a new technique and a review of urogenital anatomy

Rabbits are widely used as an animal model for urologic research studies in which urinary bladder catheterization is required. However, standard manual retrograde urinary catheterization proved to be difficult to perform on anesthetized male rabbits in a research study, with frequent misplacement of the catheter into the vesicular gland. Attempts to reposition the catheter into the bladder after initial entry into the vesicular gland frequently failed and resulted in exclusion of the animal from the study. We assessed the normal anatomy of the lower urinary tract of male rabbits to determine the cause of catheterization misdirection into the vesicular gland and to develop a more reliable technique for urinary bladder catheterization. A modified 'digital (finger) pressure' catheterization technique was developed for successful urinary catheterization of male rabbits. Retrospective statistical analysis of 45 rabbits used for urinary catheterization studies showed improvement in the success rate of catheterization by using the digital pressure technique over the standard method of retrograde urinary catheter insertion. In addition, we here review the relevant gross and histologic anatomy of the urogenital tract of male rabbits.

Simulation of the upper urinary system

The ureter and its peristalsis motions have long been of significant interest in biomechanics. In this article we review experimental, theoretical, and numerical studies of the behavior of the ureter together with its mechanical properties, emphasizing studies that contain information of importance in building a virtual simulation tool of the complete ureter that includes its complex geometry, nonlinear material properties, and interaction with urine flow. A new technique to model the contraction of a ureter, which directly applies wall forces to model pacemaker activities, is presented. The required further steps to capture the full complex movement of the peristalsis are discussed, aiming to construct a computational platform that will provide a reliable tool to assist in the investigation and design of material devices (stents) for the renal system.

Proliferative and nonproliferative lesions of the rat and mouse urinary system

The INHAND Project (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP), and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying lesions observed in the urinary tract of rats and mice. The standardized nomenclature of urinary tract lesions presented in this document is also available electronically on the Internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous developmental and aging lesions as well as those induced by exposure to test materials. A widely accepted and utilized international harmonization of nomenclature for urinary tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists.

Site-specific effects of anosmia and cloacal gland anesthesia on Fos expression induced in male quail brain by sexual behavior

In rats, expression of the immediate early gene, c-fos observed in the brain following male copulatory behavior relates mostly to the detection of olfactory information originating from the female and to somatosensory feedback from the penis. However, quail, like most birds, are generally considered to have a relatively poorly developed sense of smell. Furthermore, quail have no intromittent organ (e.g., penis). It is therefore intriguing that expression of male copulatory behavior induces in quail and rats a similar pattern of c-fos expression in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BSTM) and parts of the amygdala. We analyzed here by immunocytochemistry Fos expression in the mPOA/BSTM/amygdala of male quail that had been allowed to copulate with a female during standardized tests. Before these tests, some of the males had either their nostrils plugged, or their cloacal area anesthetized, or both. A control group was not exposed to females. These manipulations did not affect frequencies of male sexual behavior and all birds exposed to a female copulated normally. In the mPOA, the increased Fos expression induced by copulation was not affected by the cloacal gland anesthesia but was markedly reduced in subjects deprived of olfactory input. Both manipulations affected copulation-induced Fos expression in the BSTM. No change in Fos expression was observed in the amygdala. Thus immediate early gene expression in the mPOA and BSTM of quail is modulated at least in part by olfactory cues and/or somatosensory stimuli originating from the cloacal gland. Future work should specify the nature of these stimuli and their function in the expression of avian male sexual behavior.

Functional anatomy of the female lower urinary tract and pelvic floor

Stress continence depends upon three factors: proximal urethral support, vesical neck closure, and urethral contractility. The position of the vesical neck is not static but mobile and under voluntary control. Its support depends upon connections of the urethrovaginal endopelvic fascia to the medial aspect of the levator ani. In addition, these fasciae are attached to the arcus tendineus fasciae pelvis which supports the urethra during levator relaxation, and probably during stress. Levator contraction supports the proximal urethra and also pulls the vesical neck anteriorly against a band of endopelvic fascia which is suspended between the arcus tendinei, compressing it closed. Relaxation of the muscles allows the vesical neck to descend, and facilitates its opening. The connective tissue and smooth muscle of the trigonal ring encircles the vesical neck's lumen, and may contribute to closure of this area. The striated urogenital sphincter muscle can contract to assist in maintaining continence in continent women whose vesical neck is not competent. It has a circular sphincteric portion from 20 to 60% of urethral length. From 60 to 80% it has a considerable bulk of muscle which forms an arch at the perineal membrane that would compress the urethra from above.

Central neural control of the lower urinary tract

The lower urinary tract has two main functions, the storage and periodic elimination of urine, which are regulated by a complex neural control system in the brain and spinal cord. This neural system exhibits switch-like patterns of activity that are generated by visceral reflex circuits, some of which are under voluntary control. Experimental studies in animals indicate that the micturition reflex is mediated by a spinobulbospinal pathway passing through a coordination centre (the pontine micturition centre) located in the rostral brainstem. This reflex pathway is, in turn, modulated by higher centres in the cerebral cortex which are presumably involved in the voluntary control of micturition. Several neurotransmitters (including GABA, opioid peptides and glutamic acid) appear to have a role in the central pathways controlling micturition. Since pharmacological manipulation of putative inhibitory transmitter mechanisms increases bladder activity and decreases bladder capacity it is possible that similar changes induced by pathological conditions may underlie bladder dysfunctions occurring in patients with neurogenic urinary incontinence. Further study of these neurotransmitter systems may yield new therapeutic approaches for the treatment of hyperactive bladder disorders.

Minimally-invasive electrical stimulation of the pudendal nerve: a pre-clinical study for neural control of the lower urinary tract

AIMS

Electrical stimulation of afferent pudendal nerve fibers can evoke sustained bladder contractions (SBC) in cats, yet evidence of therapeutic efficacy in human subjects is lacking. This pre-clinical study was undertaken to test the hypothesis that robust bladder contractions can be generated with a minimally-invasive needle electrode.

MATERIALS AND METHODS

In seven adult cats, triggered electromyographic (EMG) signals from the external anal sphincter (EAS) were used to minimize the needle-to-nerve distance; while reflex bladder contractions were recorded as 20-sec trains of current pulses of varying amplitude (threshold to 10 mA) and frequency (1-100 Hz) were applied to the nerve. This stimulation paradigm was repeated at successively greater needle-to-nerve distances (0.5 cm intervals) and also at different electrode positions along the nerve.

RESULTS

Electrophysiological access to the pudendal nerve was consistently achieved, as indicated by the average threshold for EAS activation (0.31+/-0.19 mA). Using different combinations of stimulus amplitude and frequency, robust SBCs were evoked in every experiment. More rostral electrode positions exhibited stimulation amplitudes and corresponding maximum bladder pressures (0.68+/-0.36 mA and 25.3+/-3.5 cmH2O, respectively) that were comparable to those of more invasive stimulation methods.

CONCLUSIONS

The needle electrode provides a minimally-invasive approach that will enable the study of reflexes mediated by pudendal afferents in humans, and allow pre-operative testing before implanting a permanent device.

Does a full bladder aid upper tract visualization in magnetic resonance urography?

The aim of this study was to evaluate whether a full bladder improved the visualization of the upper renal tract during magnetic resonance urography (MRU). Twenty volunteers were recruited into the study. The MRU imaging was carried out on a 1.5-T MR system. Imaging was carried out in the coronal plane using a half-Fourier acquired single-shot turbo-spin-echo technique. All volunteers were examined in two separate MRU studies to visualize the urinary tract. The first study was carried out with a 'full' bladder followed by a study with an 'empty' bladder, leading to a total of 40 examinations. Two radiologists then reviewed maximum intensity projection images from both 'full' and 'empty' studies independently. Both left and right upper tracts were divided into five segments. A three-point grading system was used to evaluate visualization. Excellent visualization = 3, good visualization = 2 and poor visualization = 1. Maximum score per patient was 30. Results were tabulated and analysed using an Excel database. The average score for visualization for the 'full' bladder group was 22.1/30 (73.8%) and the average score for the empty bladder was 16.2/30 (54%). Overall improvement in visualization was 5.9/30 (19.8%). There was strong interobserver agreement, with a concordance value of 92.5%. The MRU carried out in healthy young adult volunteers with a full bladder allows improved visualization of the upper tracts.

[Anatomy and physiology of the lower urinary tract]

Neurogenic lower urinary tract dysfunction is frequent, due to lesions of the central and/or peripheral somatic and/or autonomic nervous system whose role is to ensure the regulation and control of lower urinary tract function. Due to the presence of both smooth and striated muscle cells in structures of the lower urinary tract, nerve pathways and nerve centres belong to both the somatic and autonomic nervous systems.

Chapitre 3 - Démarche et bilan diagnostique en neuro-urologie

This chapter is designed to propose an analysis of the diagnostic approach in neurourology based on classifications of neurogenic bladder and the therapeutic objectives to be achieved. Based on this analysis, a diagnostic flow-chart is proposed to be used as a guide in the multidisciplinary discussion and to allow a standardized approach. The surgical specificities of neurourology require certain rules of preoperative, intraoperative and postoperative management, regardless of the type of surgery performed. These rules are summarized and should constitute practice guidelines in this field.

Anatomy and physiology of urinary elimination. Part 1

Elimination of urine is an essential bodily function, but independence in this activity may be affected by physical and mental disability. Part 1 of this article discusses the anatomy and physiology of the renal and urinary tract and the production of urine. Urinalysis is a vital nursing assessment and the collection of specimens and the range of tests undertaken are outlined. Assisting patients to use the toilet, commode or bedpan is an essential nursing skill. The importance of sensitivity, empathy and moving and handling risk assessment is discussed, and the assessment and management of urinary tract infection and urinary tract stones are addressed. The importance of prevention of cross infection for nurses and patients is highlighted throughout the article.

Effect of castration on male rabbit lower urinary tract tissue enzymes

OBJECTIVES

The influence of testosterone on the prostate and corpus cavernosum have been studied extensively. However, the influence of testosterone on the lower urinary tract (bladder and urethra) have not been investigated to any great extent. The aim of this study was to determine whether androgen deprivation alters lower urinary tract metabolism.

METHODS

A total of 16 rabbits were divided into four groups of four rabbits each. Each rabbit in groups 1-3 underwent surgical bilateral castration for duration of 1, 2 , and 4 weeks, and group 4 underwent sham operations. Sections of bladder body and base wall and mucosa, urethra and corpora were isolated, frozen, and stored under liquid nitrogen. The activities of citrate synthase-thapsigargin sensitive Ca(2+) ATPase (Sarco/Endoplasmic Reticulum Ca(2+ )ATPase [SERCA]), and choline acetyl-transferase were examined as markers for mitochondrial function, sarcoplasmic reticular calcium storage and release, and cholinergic nerve function, respectively.

RESULTS

The activity of SR function indicator, Ca(2+) ATPase was significantly higher in the control corpora than in the control bladder or urethra. Castration resulted in decreased activity in the mitochondria specific enzyme, citrate synthase, the activity of which was greatest in the urethra and lowest in the corpora. Cholinergic nerve density indicator, choline acetyl-transferase activity was greatest in the bladder body and lowest in the urethra.

CONCLUSIONS

Our data indicate that (1) significant differences exist in the activities of all three enzymes in the various organs associated with the lower urinary tract; and (2) that castration results in significant alterations in the activities of all three enzymes in the bladder body, base, urethra, and corpora.

Insertion of a urinary catheter

Although a common procedure in the care of older people, the insertion of a urinary catheter carries considerable risk--for example, from infection or trauma. Changing demographics mean that the number of older people requiring catheterisation is likely to increase. This article explores the incidence of catheter use and associated complications, and explains the correct procedure for catheter insertion.

Pelvic Floor Muscle Biofeedback in the Treatment of Urinary Incontinence: A Literature Review

Biofeedback is efficacious in the training of the pelvic floor musculature in order to enhance continence. This article reviews the anatomy and physiology of micturition as the underlying rationale for pelvic floor muscle biofeedback in the treatment of urinary incontinence. It critically reviews 28 studies published in peer reviewed journals from 1975 to 2005 that were prospective, randomized studies with parametric statistical analyses, operationally defined patient selection criteria, treatment protocols and outcome measures. The overall mean treatment improvement for patients undergoing biofeedback for urinary incontinence was 72.61%. In 21 of 35 (60%) paired comparisons, biofeedback demonstrated superior symptomatic outcome to control or alternate treatment groups. Larger studies and a standardization of technology and methodology are required for more conclusive determinations.

Midline extraperitoneal approach to upper urinary tract surgery: Anatomical basis of surgical technique

AIM

To overcome the disadvantages inherent in the standard surgical approach to the kidney, we introduced a novel surgical technique via a midline extraperitoneal approach. The surgical technique is not substantially different from that of the standard midline transperitoneal approach, except no entry is made into the peritoneal cavity. Although the peritoneum itself is extremely thin and fragile, the peritoneum together with underlying subperitoneal fascia can be dissected readily as a substantial layer, if the proper plane is dissected. Further medial mobilization of the peritoneal sac en bloc by pursuing the fusion fascia plane allows full exposure of the kidney, ureter and great vessels. This approach was adopted for consecutive 51 patients during a 10-month period in 2003. All operations, including 33 radical nephrectomies and 11 nephroureterectomies were completed successfully without significant technical difficulties and differences in operation time and estimated blood loss compared to the transperitoneal approach. No intra- or perioperative complication occurred. All patients did seem to have a much more comfortable postoperative period with minor pain and few abdominal complaint, and the clinical impression was that they resumed the physical activity and oral intake earlier than those after the transperitoneal approach (P = 0.056). There are no operation-related problems such as intra-abdominal adhesion or abdominal muscle weakness resulting in some deformity at 2-year or more follow up. This approach combines the advantages of the transperitoneal midline and extraperitoneal flank approach. Its use will undoubtedly reduce the complications inherent in the transperitoneal approach or the flank approach.

Development and differentiation of the ureteric bud into the ureter in the absence of a kidney collecting system

Six1-/- mice were found to have apparently normal ureters in the absence of a kidney, suggesting that the growth and development of the unbranched ureter is largely independent of the more proximal portions of the UB which differentiates into the highly branched renal collecting system. Culture of isolated urinary tracts (from normal and mutant mice) on Transwell filters was employed to study the morphogenesis of this portion of the urogenital system. Examination of the ureters revealed the presence of a multi-cell layered tubule with a lumen lined by cells expressing uroplakin (a protein exclusively expressed in the epithelium of the lower urinary tract). Cultured ureters of both the wild-type and Six1 mutant become contractile and undergo peristalsis, an activity preceded by the expression of alpha-smooth muscle actin (alphaSMA). Treatment with a number of inhibitors of signaling molecules revealed that inhibition of PI3 kinase dissociates the developmental expression of alphaSMA from ureter growth and elongation. Epidermal growth factor also perturbed smooth muscle differentiation in culture. Moreover, the peristalsis of the ureter in the absence of the kidney in the Six1-/- mouse indicates that the development of this clinically important function of ureter (peristaltic movement of urine) is not dependent on fluid flow through the ureter. In keeping with this, isolated ureters cultured in the absence of surrounding tissues elongate, differentiate and undergo peristalsis when cultured on a filter and undergo branching morphogenesis when cultured in 3-dimensional extracellular matrix gels in the presence of a conditioned medium derived from a metanephric mesenchyme (MM) cell line. In addition, ureters of Six1-/- urinary tracts (i.e., lacking a kidney) displayed budding structures from their proximal ends when cultured in the presence of GDNF and FGFs reminiscent of UB budding from the wolffian duct. Taken together with the above data, this indicates that, although the distal ureter (at least early in its development) retains some of the characteristics of the more proximal UB, the growth and differentiation (i.e., development of smooth muscle actin, peristalsis and uroplakin expression) of the distal non-branching ureter are inherent properties of this portion of the UB, occurring independently of detectable influences of either the undifferentiated MM (unlike the upper portion of the ureteric bud) or more differentiated metanephric kidney. Thus, the developing distal ureter appears to be a unique anatomical structure which should no longer be considered as simply the non-branching portion of the ureteric bud. In future studies, the ability to independently analyze and study the portion of the UB that becomes the renal collecting system and that which becomes the ureter should facilitate distinguishing the developmental nephrome (renal ontogenome) from the ureterome.

ULTRASONOGRAPHY OF THE LIVER, SPLEEN, AND URINARY TRACT OF THE CHEETAH (ACINONYX JUBATUS)

Diseases of the abdomen of the cheetah (Acinonyx jubatus) include those affecting the liver, spleen, and urinary tract. The most common diseases of captive-bred cheetah are gastritis, gastric ulceration, glomerulosclerosis, and hepatic veno-occlusive disease, and are the most frequent causes of mortality in these animals. The purpose of this study was to describe the ultrasonographic anatomy of the normal liver, spleen, kidney, and urinary bladder of the anesthetized captive-bred cheetah. Twenty-one cheetahs were examined. Eight of the 21 animals had subclinical evidence of either gastritis or chronic renal disease. The ultrasonographic appearances of the liver, gall bladder, common bile duct, and spleen were evaluated and various measurements made. Statistical analyses of the measurements were performed on all the healthy and subclinically ill animals taking sex, age, mass, and anesthetic protocol into account. There were no significant differences in any parameters between the healthy and subclinically ill animals (P > 0.25) and data were combined for statistical analyses. The mean mass was 41.1kg ( +/- 8.8) and the mean age was 5.0 years (+/- 2.2). The mean thickness of the liver medial to the gall bladder was 67.0 mm (+/- 14.8) and the liver was within the left costal arch in 75% of animals, extended caudal to the right costal arch in 50% of animals for an average of 30 mm, and extended caudal to the sternum in 63% of animals for an average of 32.5 mm. The maximum mean hepatic vein diameter at the entrance to the caudal vena cava was 8.6 +/- 2.8 mm; the mean diameters of the portal vein at the hilus and that of the caudal vena cava as it entered the liver were 7.5 +/- 1.6 and 9.9 +/- 4.1 mm, respectively. The mean diameter of the caudal vena cava was significantly affected by the type of anesthetic used (P < 0.10). The mass of the animals was significant in explaining the variance in maximum portal vein diameters (P < 0.10). The mean maximum velocity of the hepatic vein flow at the entrance to the caudal vena cava was 25.3 +/- 2.8 cm/s (n=4), the hilar portal vein was 11.7 +/- 3.3 cm/s (n=7), and the caudal vena cava was 33.8 +/- 19.8 cm/s (n=5). The mean maximum gall bladder length and width, and the mean common bile duct diameters were 44.6 mm (+/- 10.4), 23.3 mm (+/- 5.0), and 8.1 mm (+/- 2.4), respectively. Age was significant in explaining the variance in gall bladder lengths (P<0.10). Urinary tract ultrasonography was performed only in animals that had normal urea and creatinine levels (n=13). Renal cortico-medullary distinction was present in all kidneys and a cortico-medullary rim sign was seen in 21 of 26 kidneys. Mean kidney length, height, and width was 63.9 +/- 5.7, 38.1 +/- 5.2, and 42.1 +/- 5 mm, respectively. The average resistivity index was 0.58 (n=5). Mean urinary bladder length, height, and width were 57.0, 19.2, and 34.9 mm, respectively.

Congenital progressive hydronephrosis (cph) is caused by an S256L mutation in aquaporin-2 that affects its phosphorylation and apical membrane accumulation

Congenital progressive hydronephrosis (cph) is a spontaneous recessive mutation that causes severe hydronephrosis and obstructive nephropathy in affected mice. The mutation has been mapped to the distal end of mouse chromosome 15, but the mutated gene has not been found. Here, we describe the identification of a single base pair change in aquaporin-2 (Aqp2) in cph mutants through genetic linkage mapping. The C-T change led to the substitution of a Ser (S256) by a Leu in the cytoplasmic tail of the Aqp2 protein, preventing its phosphorylation at S256 and the subsequent accumulation of Aqp2 on the apical membrane of the collecting duct principal cells. The interference with normal trafficking of Aqp2 by this mutation resulted in a severe urine concentration defect. cph homozygotes demonstrated polydipsia and produced a copious amount of hypotonic urine. The urine concentration defect could not be corrected by [deamino-Cys1,D-Arg8]-vasopressin (DDAVP, a vasopressin analog), characteristic of nephrogenic diabetes insipidus. The nephrogenic diabetes insipidus symptoms and the absence of developmental defects in the pyeloureteral peristaltic machinery in the mutants before the onset of hydronephrosis suggest that the congenital obstructive nephropathy is most likely a result of the polyuria. This study has revealed the genetic basis for the classical cph mutation and has provided direct genetic evidence that S256 in Aqp2 is indispensable for the apical accumulation, but not the general glycosylation or membrane association, of Aqp2.

Pathophysiology of overactive bladder

Overactive bladder (OAB) is a complex of symptoms frequently encountered in the primary care setting. Impediments to optimal management of OAB include inaccurate perceptions on the part of patients and primary care providers, e.g., that the symptoms of OAB represent a natural progression of aging and are beyond the scope of treatment or that diagnosis and treatment are specialist concerns. Complicating the physician's task is the reluctance of many patients to initiate discussion of their OAB symptoms and the fact that patients often develop disruptive coping strategies rather than seek medical treatment, possibly because of a belief that OAB is a normal part of aging rather than an actual medical condition. In most cases, OAB may be managed quite well by the primary care physician who has an understanding of the pathophysiology of OAB. This article reviews normal bladder function and then explores pathophysiologic changes that likely cause the symptoms of OAB.

Nursing management of paediatric urethral catheterisation

This article outlines evidence-based approaches to paediatric catheterisation in acute care settings. The reasons for catheterisation, anatomy and physiology of the urinary system and the procedure and potential complications are discussed.

[Anatomical and surgical meaning of the bladder during the performance of radical hysterectomy]

During the performance of radical hysterectomies in the everyday practice, oncologists continuously face difficulties and problems related to the urinary tract at the time of early and late postoperative period and occasionally intraoperatively. Bladder complications are hypo- and atonia, which may lead to hydroyreter and hydronephrosis. These hypo- and atonia sometimes delate adjuvant therapies and this influences therapeutic results. Thus in the present review are reported the blood supply, nerve structures and bladder function, which preserving may result in less complications after radical hysterectomy

[Anatomical and surgical meaning of the ureters during the performance of radical hysterectomy]

During the pelvic surgery ureters are dissected until they flow to the bladder. For this reason surgen must be knowleadgable about the anatomy of the vesico-ureteral unit and the blood supply of the ureters,because the majority of the early and late complications, especially following pelvic irradiation,are related to the function of kidneys and ureters. In the present review attention is paid on the ureters as an anatomical marker during the performance of radical hysterectomy and on the possible intraoperative complications, identification and avoidance of ureteral injuries,as well. Authors also discussed on the management of ureteral damages.

Pharmacology of the lower urinary tract: basis for current and future treatments of urinary incontinence

The lower urinary tract constitutes a functional unit controlled by a complex interplay between the central and peripheral nervous systems and local regulatory factors. In the adult, micturition is controlled by a spinobulbospinal reflex, which is under suprapontine control. Several central nervous system transmitters can modulate voiding, as well as, potentially, drugs affecting voiding; for example, noradrenaline, GABA, or dopamine receptors and mechanisms may be therapeutically useful. Peripherally, lower urinary tract function is dependent on the concerted action of the smooth and striated muscles of the urinary bladder, urethra, and periurethral region. Various neurotransmitters, including acetylcholine, noradrenaline, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in this neural regulation. Muscarinic receptors mediate normal bladder contraction as well as at least the main part of contraction in the overactive bladder. Disorders of micturition can roughly be classified as disturbances of storage or disturbances of emptying. Failure to store urine may lead to various forms of incontinence, the main forms of which are urge and stress incontinence. The etiology and pathophysiology of these disorders remain incompletely known, which is reflected in the fact that current drug treatment includes a relatively small number of more or less well-documented alternatives. Antimuscarinics are the main-stay of pharmacological treatment of the overactive bladder syndrome, which is characterized by urgency, frequency, and urge incontinence. Accepted drug treatments of stress incontinence are currently scarce, but new alternatives are emerging. New targets for control of micturition are being defined, but further research is needed to advance the pharmacological treatment of micturition disorders.

Is the rhesus monkey (Macaca mulatta) comparable to humans? Histomorphology of the sphincteric musculature of the lower urinary tract including 3D-reconstruction

The physiology of the muscle systems of the human lower urinary tract is still not known in detail. To study the functional basics of this complex organ system, experiments are often performed in animal models including rhesus monkeys. To apply the results of animal model studies to the humans, a clear knowledge of the comparative anatomy of both species is necessary. However, detailed comparative studies of the lower urinary tract of the rhesus monkey and the humans are lacking. Accordingly, a detailed study on the sphincteric musculature of the lower urinary tract of the rhesus monkey was performed in order to demonstrate anatomical correspondences and differences between both species. The lower urinary tract anatomy was investigated in 18 male and female rhesus monkeys (Macaca mulatta) by serial sections. Immunohistochemical staining methods were used to differentiate striated and smooth musculature. Three-dimensional reconstructions were performed in order to demonstrate the topographical anatomy of the different muscle systems. In both man and male rhesus monkeys, a urethral sphincter muscle exists independent of the pelvic floor musculature, with a smooth and a striated muscular part. A urinary diaphragm (diaphragma urogenitale) does neither exist in the rhesus monkey nor in the human. In contrast to women, a striated muscle encircles the urethra and vagina together in the female rhesus monkey. A vesical sphincter muscle, found in the human bladder outlet, does not exist in the rhesus monkey.

Force-length relationship in the pelvic floor muscles under transverse vaginal distension: a method study in healthy women

AIMS

The purpose of this study was to investigate whether there is a relationship between changes in the diameter of the urogenital hiatus and force developed in pelvic floor musculature. In addition, we wanted to examine the reliability of the method that measures force development in the pelvic floor in the transverse direction of the urogenital hiatus.

MATERIALS AND METHODS

Passive and total force in the pelvic floor was measured with an intra-vaginal device in 20 healthy parous volunteers. The measurements were done with a consecutively increasing diameter in the transverse plane of the urogenital hiatus. The procedure was repeated with a few days interval.

RESULTS

The measurements show an increase in force with an increasing device-diameter. The results are reliable at all the diameters tested, estimated by the within-subject day-to-day variability which was non-significant. The 40 mm diameter device is most favourable, estimated by Bland Altman plots of the test-retest measurements.

CONCLUSIONS

Force development in pelvic floor muscles increased as a function of vaginal diameter when measured in the frontal plane. The measurements were reliable at all the different diameters chosen.

Anatomic and physiologic considerations in ureteroscopy

The successful and safe implementation of ureteroscopic techniques depends on considerations of anatomy and physiology. Combining knowledge of the drainage system of the kidney with its vascular supply, predictive patterns of incisions can be applied within the collecting system to safely avoid vascular injury. In addition, awareness of the variation in normal and pathologic anatomy and physiology is key to effective interventions. An appreciation of the impact of ureteroscopy on normal anatomy and physiology can prevent complications and promote improved therapeutic outcomes.

Magnetic resonance urography by virtual reality modelling

PURPOSE

The purpose of this study was to create a 3D visualization of the urinary tract by a novel virtual reality approach, and to evaluate the usefulness of this method for papillary classification as compared with 2D urogram obtained by maximum intensity projection (MIP).

MATERIALS AND METHODS

In one healthy pig, magnetic resonance urography was performed using a T1-weighted 3D gradient echo pulse sequence. Post-processing was performed by means of an MIP algorithm and by using 3D virtual reality modelling, followed by manual classification of papillae as being either simple or compound.

RESULTS

The 2D MIP urogram demonstrated 6 simple and 6 compound papillae, whereas the 3D urogram demonstrated 5 simple and 7 compound papillae. In both urograms, some papillae were unsuccessfully classified.

CONCLUSION

The possibility of using virtual reality devices allowed 3D rotation and offered additional diagnostic information. However, further studies should reveal its feasibility in diseased kidneys.

MR urography: evaluation of different techniques in non-dilated tracts

OBJECTIVE

To assess the effectiveness of different MRI sequences for the visualisation of the different components of the non-dilated urinary tract.

METHOD

20 asymptomatic individuals were prospectively evaluated using 2 different heavily T2 weighted sequences, and after the injection of 2 different doses of gadolinium (Gd-DTPA). Images were independently scored.

RESULTS

The low dose Gd-DTPA enhanced MR urography (MRU) sequence was the best overall sequence for the visualisation of both the pelvicalyceal systems and ureters. The combination of information from the other sequences was additive.

CONCLUSIONS

Combined use of heavily T2 weighted and Gd-DTPA enhanced MRU produces diagnostic images and does not require pre-imaging preparation other than oral hydration.

Is the male dog comparable to human? A histological study of the muscle systems of the lower urinary tract

Because of their superficial anatomical resemblance, the male dog seems to be suitable for studying the physiologic and pathological alterations of the bladder neck of human males. The present study was carried out to compare and contrast the muscular anatomy of the male dog lower urinary tract with that of humans. The complete lower urinary tract, including the surrounding organs (bulb of penis, prostate, rectum and musculature of the pelvic floor) were removed from adult and newborn male dogs and histologically processed using serial section technique. Based on our own histological investigations, three-dimensional (3D)-models of the anatomy of the lower urinary tract were constructed to depict the corresponding structures and the differences between the species. The results of this study confirm that the lower urinary tract of the male dog bears some anatomical resemblance (musculus detrusor vesicae, prostate, prostatic and membranous urethra) to man. As with human males, the two parts of the musculus sphincter urethrae (glaber and transversostriatus) are evident in the canine bladder neck. Nevertheless, considerable differences in formation of individual muscles should be noted. In male dogs, no separate anatomic entity can be identified as vesical or internal sphincter. The individual course of the ventral and lateral longitudinal musculature and of the circularly arranged smooth musculature of the urethra is different to that of humans. Differences in the anatomy of individual muscles of the bladder neck in the male dog and man suggest that physiological interpretations of urethral functions obtained in one species cannot be attributed without qualification to the other.

MR urography in children

Thanks to the development of rapid sequences with better resolution, applications of uro MR have rapidly increased in children. Difficulties that remain are related to the variable ages of the patients. It is therefore mandatory to standardize as much as possible the techniques that are used in order to obtain reproducible results. In this review, the examination protocols will be explained. In a second part the current applications in children will be illustrated and discussed, especially in comparison with the other imaging techniques.