The new Malone antegrade continence enema automatic instillation device allows independence and decreases flush times

PURPOSE

The Malone antegrade continence enema procedure has changed the lives of many school-aged children who would otherwise be in diapers. Unfortunately, our current procedures to flush the Malone antegrade continence enema are difficult to accomplish independently and require an extensive time commitment. In this study we confirm that a new device, the ACE Malone automatic instillation device (ACE-MAID) is safe and effective, will decrease the time it takes to perform the flush and will increase independence.

MATERIALS AND METHODS

Nine patients were prospectively enrolled for a 1-year study. Patient age ranged from 4 to 16 years, and diagnoses included spina bifida (3 cases), imperforate anus (4) and infantile meningitis (1). The study consisted of initial and followup questionnaires, an "ACE-O-Gram," quality assurance testing of the ACE-MAID and an objective observation of current flushing technique.

RESULTS

The average objective start to finish flush time decreased from 45 minutes initially to 31 minutes using the ACE-MAID. Children who initially had more than 1 accident per month had a decrease in the number of stool accidents. When asked to compare the ACE-MAID device to the previous form of flushing 100% of patients stated that it was better. When asked if they would use the pump when the study was over 100% reported yes.

CONCLUSIONS

The new ACE-MAID proved safe and effective, decreased flush times, may decrease stool accidents and facilitates independence for children treated with a MACE procedure.

Linear growth after enterocystoplasty in children and adolescents: a review

The interposition of bowel in continuity with the urinary tract has allowed for the preservation of renal function and continence in children with bladder exstrophy, as well as neurogenic and valve bladders. Although bladder augmentation with ileum or colon has been shown to be safe, the long-term effects of metabolic acidosis in addition to abnormalities in linear growth and bone metabolism remain largely unknown. We reviewed the literature to critically examine linear growth in children who have had bladder augmentation with a particular emphasis on the correlation between acid-base status, bone mineralization and growth. The majority of studies suggest that linear growth is not affected by bladder augmentation. In the short-term, children post-augmentation have varying degrees of metabolic acidosis which, overtime, appears to resolve with no affect on linear growth. In a single study, bladder augmentation led to significant bone demineralization almost a decade after surgery, however, even in these children no decrease in linear growth was noted. No alterations in bone density levels were seen with short-term follow-up.

ABNORMAL DIMERCAPTO-SUCCINIC ACID SCANS PREDICT AN INCREASED RISK OF BREAKTHROUGH INFECTION IN CHILDREN WITH VESICOURETERAL REFLUX

PURPOSE

The management of high grade vesicoureteral reflux remains controversial, with breakthrough infections being an indication for surgical repair. We sought to determine if technetium dimercapto-succinic acid (DMSA) scan could help predict which children are at risk for breakthrough urinary tract infection.

MATERIALS AND METHODS

A retrospective review was performed on children presenting with a febrile urinary tract infection and prenatal hydronephrosis who were found to have vesicoureteral reflux and underwent a DMSA scan. Reflux was tabulated according to the highest grade. DMSA results were graded as 0-normal, no parenchymal or size defects, grade 1-focal parenchymal defects or less than a quarter of a renal unit involved, or grade 2-severe defects to include at least half of a renal unit, bilateral defects or unilateral atrophy.

RESULTS

A total of 120 consecutive patients were evaluated. An abnormal DMSA scan was documented in 57 (33 females and 24 males), and 35 with grade 1 and 22 with grade 2 defects. Of the patients 53 females and 10 males had a normal scan. Of the 57 children with an abnormal DMSA scan 6% presented with grades 1 and 2 vesicoureteral reflux, 24% with grade 3, 38% with grade 4 and 26% with grade 5. Of the children with grades 3 to 5 reflux 60% had a subsequent breakthrough infection. Of the 63 children with a normal DMSA scan 11% presented with grade 1 reflux, 28% with grade 2, 48% with grade 3, 11% with grade 4 and 2% with grade 5. Of these children 5 had a subsequent breakthrough infection.

CONCLUSIONS

An abnormality on DMSA scan in the presence of grade 3 to 5 reflux correlates with a greater chance of having a breakthrough infection (60%). We conclude that children with grade 3 to 5 vesicoureteral reflux and an abnormal DMSA scan are at increased risk for breakthrough urinary tract infection.

Anatomical studies of the mouse genital tubercle

BACKGROUND

To study the etiology of hypospadias, we propose the use of a mouse model, the embryonic mouse genital tubercle. In this study, we define the development of the mouse genital tubercle with special emphasis on urethral formation demonstrating anatomical similarities to human development.

MATERIALS AND METHODS

Serial sections of genital tubercles from embryonic male and female mice ages 14 to 21 days gestation from timed pregnant animals, newborn and adult mice were immunohistochemical stained with antibodies to E-cadherin, cytokeratins 7, 10, and 14. Patency of the urethral was assessed by india ink injection via the bladder. Urethral lumen morphology was determined by the creation of plastic resin cast. Surface morphology of the genital tubercle was defined by scanning electron microscopy.

RESULTS

India Ink injection into the bladder showed that the urethral lumen was patent from 14 days gestation. Plastic resin casts revealed that the male urethra was characterized by a S shaped curve, the presence of the bulbar urethral gland and a longer length than age matched females. The ontogeny of the genital tubercle development revealed two epithelial edges that subsequently touched and fused into the completed urethra. During development cytokeratin immunohistochemical staining demonstrated that the epithelial cells of the urethral lumen are of bladder origin and the surface cells of skin origin.

CONCLUSION

The functional and developmental anatomy of the mouse genital tubercle provides a useful model to study normal and abnormal human urethral development.

NEUROANATOMY OF THE HUMAN FEMALE LOWER UROGENITAL TRACT

PURPOSE

The neuroanatomy of the female lower urogenital tract remains controversial. We defined the topographical anatomy and differential immunohistochemical characteristics of the dorsal nerve of the clitoris, the cavernous nerve and the nerves innervating the female urethral sphincter complex.

MATERIALS AND METHODS

A total of 16 normal female human pelvic specimens at 14 to 34 weeks of gestation were studied by immunohistochemical techniques. Serial sections were stained with antibodies raised against the neuronal markers S-100 and neuronal nitric oxide synthase (nNOS), vesicular acetylcholine transporter, calcitonin gene-related peptide and substance P. The serial sections were computer reconstructed into 3-dimensional images.

RESULTS

Under the pubic arch at the hilum of the clitoral bodies the branches of the cavernous nerves joined the clitoral dorsal nerve to transform its immunoreactivity to nNOS positive. The cavernous nerves originated from the vaginal nervous plexus occupying the 2 and 10 o'clock positions on the anterolateral vagina and they traveled at the 5 and 7 o'clock positions along the urethra. The urethral sphincter complex was innervated by nNOS immunoreactive and nonimmunoreactive nerve fibers arising from the vaginal nervous plexus and pudendal nerve, respectively.

CONCLUSIONS

The dorsal nerve of the clitoris receives nNOS positive branches from the cavernous nerve as a possible redundant mechanism for clitoral erectile function. The urethral sphincter complex has dual innervation, which pierces into the urethral sphincter complex at different locations. The study of the neuroanatomy of the female lower urogenital tract is germane to the strategic design of female reconstructive surgery.

Children with a febrile urinary tract infection and a negative radiologic workup: factors predictive of recurrence

OBJECTIVES

To determine the recurrence rate and risk factors for urinary tract infection (UTI) in children who present with a febrile UTI and have a negative radiologic evaluation. Febrile UTIs with no urinary tract abnormalities are a common cause of morbidity in children.

METHODS

We performed a retrospective review of all children referred to our medical center after a febrile UTI.

RESULTS

We reviewed 850 charts. Of 850 children, 78 had had a febrile UTI and normal ultrasound and voiding cystourography findings. Of the 78 children, 25 had had a recurrent UTI (3 boys and 22 girls). Forty-five percent of the girls with a febrile UTI developed a recurrent UTI and 14% of the boys had a recurrent UTI (P = 0.02). Three boys (two younger than 1 year of age) were uncircumcised and had one recurrent febrile UTI. Eleven (39%) of 28 girls who first presented at younger than 1 year of age and 7 (58%) of 12 girls who presented at 5 years of age or older had recurrent UTIs. The recurrence rate in the 2 to 5-year-old age group was 24% (4 of 17). Seven of the older girls exhibited symptoms of dysfunctional elimination syndrome.

CONCLUSIONS

In children with a febrile UTI and a negative radiologic evaluation, recurrence was more common in girls. Boys who were uncircumcised may be at an increased risk of infection during the first year of life. In girls, the age at the time of the first infection was not predictive of recurrence. Although dysfunctional voiding and elimination may contribute to recurrent febrile UTIs in young children, an association seems to be present in children 5 years old and older.

Lack of defects in androgen production in children with hypospadias

Formation of the male urethra requires the synthesis of testosterone, its activation to dihydrotestosterone (DHT) in genital skin, and binding of DHT to the androgen receptor. Defects in any of those steps can cause hypospadias. To determine whether defects exist in the production of androgens in individuals with hypospadias, we examined enzymatic function of 3beta-hydroxysteroid dehydrogenase (3betaHSD), P450c17 (17alpha-hydroxylase and 17,20 lyase activity), and type 3 17betaHSD. Sixty-eight subjects participated in the study: 48 patients had hypospadias, and 20 had normal male genitalia. Subjects were stratified into groups based on age and severity of hypospadias, as defined by location of the urethral meatus after correction of penile curvature. Hormonal values in boys with hypospadias were compared by nonparametric analysis with those in age-matched controls. Controls excluded individuals with cryptorchidism, micropenis, known endocrine defects, or receiving steroid supplementation. Morning fasting serum levels of pregnenolone, progesterone, 11-deoxycorticosterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, dehydroepiandrosterone, androstenedione, androstenediol, testosterone, and DHT were determined. To focus on the proximal steps in androgen biosynthesis, 12 individuals with hypospadias underwent standard ACTH stimulation. No significant differences in the androgen precursors and metabolites were found between controls and individuals with hypospadias. The response to ACTH was variable without a significant difference between the patients with different degrees of hypospadias and/or published controls. These data indicate that enzymatic defects in the steroidogenic steps from cholesterol to DHT are not a common etiology of hypospadias. Routine abnormalities in the androgen biosynthetic pathway are an unlikely cause of any degree of hypospadias in boys without accompanying cryptorchidism or genital malformations.

An anatomical description of the male and female urethral sphincter complex

PURPOSE

We performed a detailed study of the lower urinary tract of the male and female human fetus to elucidate the anatomy of the urethral sphincter complex in both sexes and its relationship to the surrounding organs and tissues.

MATERIALS AND METHODS

A total of 12 male and 14 female normal human pelvic specimens ranging from 17.5 to 38 weeks of gestation were studied by serial sections and immunohistochemical analysis. Three-dimensional reconstructions were created from serial sections to demonstrate the anatomy of the lower urogenital tract and urethral sphincter in both sexes. Specific attention was directed to the sphincteric muscle of the urethra.

RESULTS

The urinary continence mechanism is formed by a combination of detrusor, trigone and urethral sphincter muscles with distinctive histological characteristics in both sexes. In males the external urethral sphincter covers the ventral surface of the prostate as a crescent shape above the verumontanum, horseshoe shape below the verumontanum and crescent shape along the proximal bulbar urethra. The levator ani muscles form an open circle around the external sphincter with a hiatus at the ventral aspect. In females the external urethral sphincter covers the ventral surface of the urethra in a horseshoe shape. Caudally the same horseshoe-shaped external sphincter increases in size to envelop the distal vagina. The levator ani muscles do not support the proximal urethra. The smooth and striated muscle components of the urethral sphincter complex are inseparable in both sexes.

CONCLUSIONS

The developmental anatomy of the urethral sphincter complex is analogous in both sexes. The male and female urinary sphincter mechanism is composed of detrusor, trigone and urethral muscles, each of different muscular origins. The levator ani does not surround the ventral aspect of the urethra and may not have an active role in continence in both sexes. This new concept in the anatomy of male and female sphincter morphology may help to refine our reconstructive and ablative surgical techniques.

The Distribution of Neuronal and Inducible Nitric Oxide Synthase in Urethral Stricture Formation

PURPOSE

The distribution of neuronal (n) and inducible (i) nitric oxide synthase (NOS) may have a role in the maintenance of normal urethral spongiosum and during the development of spongiofibrosis in urethral stricture disease.

MATERIALS AND METHODS

Eight normal and 33 strictured human bulbar urethras were studied by histological and immunohistochemical techniques for the neuronal markers S-100, nNOS and iNOS. The smooth muscle-to-collagen ratio was calculated by morphometric analysis of Masson's trichrome sections. Immunohistochemical staining patterns of the neuronal markers in normal urethral tissue was compared to that in urethral stricture tissue with spongiofibrosis.

RESULTS

The smooth muscle-to-collagen ratio was significantly lower in the strictured urethra compared to that in the control group (p = 0.001). In the strictured bulbar urethra nNOS immunoreactivity was decreased compared to that in normal urethral tissue. The severity of spongiofibrosis corresponded to the loss of nNOS immunoreactivity. iNOS immunoreactivity was found in strictured urethral epithelium and spongiosal tissue, whereas the control group was nonimmunoreactive to iNOS.

CONCLUSIONS

Urethral stricture formation is a fibrotic process associated with significant changes in NOS metabolism. Abnormal collagen synthesis following urethral trauma may be stimulated by inappropriate iNOS activity. A functional nerve supply to the urethral spongiosum seems to be crucial in the maintenance of the unique ultrastructure of the urethral spongiosum.

Anatomical studies of the female genitalia: surgical reconstructive implications

Surgery for patients with genital ambiguity must be based on an accurate diagnosis, thorough understanding of the genital anatomy and realistic expectations for the patient, family and treating multi-specialty team. The goal is to create a functional and cosmetic outcome consonant with the gender assignment with the least amount of morbidity to the patient and family. An understanding of the normal genital neuroanatomy is essential for a successful surgical approach and outcome. Based on fetal human specimens, we have refined the three-dimensional relationship of the dorsal nerve of the clitoris, the female cavernosal nerve and the vaginal plexus. The surgical approach to patients with severe clitoral virilization should preserve erectile function and the neural innervation of the clitoris. When indicated, surgery should be performed in infancy to minimize psychological trauma and surgical complications from scarring. Herein, we review the neuroanatomy of the female genitalia and the implications for the rare patient who needs surgical reconstruction.

Induction of hypospadias in a murine model by maternal exposure to synthetic estrogens

We tested the hypothesis that maternal exposure to synthetic estrogen can cause hypospadias in male offspring and defined the morphological changes in the disrupted urethral seam. Timed pregnant C57/6 mice were exposed to synthetic estrogens. The genital tubercles were examined for the presence of hypospadias using histology, three-dimensional computer reconstruction, and plastic cast injection molds of the urethra. Microscopic serial analysis confirmed the presence of hypospadias, which occurred in approximately 50% of the synthetic-estrogen-treated male fetuses. No effect was seen in the female embryos. Plastic cast injection showed that affected males had a shorter total urethral length and loss of male anatomic features such as the prostatic utricle. Exposure to synthetic estrogens during pregnancy affects the normal development of the urethra in the mouse. We conclude that endocrine disrupters play an important role in genital tubercle anomalies.

The effect of oestrogen and testosterone on the urethral seam of the developing male mouse genital tubercle

OBJECTIVES

To describe the effects of exogenous oestrogens and androgens on urethral formation in the mouse, as the development of the mouse and human urethra have significant similarities, and understanding normal male urethral development may help to identify the causes of abnormal development, e.g. hypospadias.

MATERIALS AND METHODS

Timed-pregnant C57/6 mice were exposed to synthetic oestrogens and androgens. The morphology of the genital tubercles was examined histologically and with three-dimensional computer reconstruction. Specific attention was focused on the developing urethral seam.

RESULTS

Microscopic serial analysis confirmed the presence of an arrest in seam formation in about half of oestrogen-treated male fetuses. In contrast, there was acceleration of urethral fold fusion and a longer urethral tube in those treated with androgens. Oestrogen-treated fetuses had a thin periurethral spongiosa, in contrast to androgen-treated fetuses which developed a thicker periurethral spongiosa. The effect of oestrogens on seam area formation did not depend on the dose, but in contrast, in the androgen-treated fetuses it was.

CONCLUSION

Oestrogens and androgens have a direct effect on the fusion of the urethral fold that leads to seam formation. Normal urethral development depends on the delicate balance of these complementary hormones.

Anatomical Studies of the Fibroblast Growth Factor-10 Mutant, Sonic Hedge Hog Mutant and Androgen Receptor Mutant Mouse Genital Tubercle

OBJECTIVES

Congenital genital abnormalities have a diverse spectrum from hypospadias to cloacal anomalies. The molecular events in the normal and abnormal development of the genital tubercle (GT) are still obscure. Genetically engineered mice with specific gene deletions that affect genital anatomy are a useful tool to better understand the etiology of genital abnormalities. In this study, we compared the genital tubercle anatomy of the androgen receptor (AR) deficient, fibroblastic growth factor (FGF)-10 deficient and Sonic HedgeHog (Shh) deficient mutant male mice to that of the wild type male and female mouse.

MATERIALS AND METHODS

The lower pelvis of the androgen receptor deficient, FGF-10 deficient, Shh deficient mutant male and wild type male and female mouse at different gestational days (E13-21) and post natal ages (1 day-1 week) were studied. GTs were imaged, serially sectioned and stained immunohistochemically with antibodies raised against E-Cadherin, Cytokeratin 7, 10 and 14. Serial sections of the GTs were selected and three-dimensional computerized images were created to better elucidate the anatomy.

RESULTS

AR deficient mutant male mouse revealed a distinctive GT anatomy, different from both sexes. The corporal bodies and glans remained hypoplastic whereas the urethral spongiosa was more developed than the wild type female counterpart. This finding is consistent with the AR mutant mouse being a unique morphologic phenotype distinct from the normal male and female. FGF-10 deficient mutant male mouse revealed normal corporal bodies with failure of the urethral plate to fuse ventrally consistent with hypospadias. The Shh deficient mutant mouse demonstrated complete agenesis of GT outgrowth and a persistent cloaca.

CONCLUSION

Animal models bred by gene knockout technology or natural occurring mutants contribute to the basic understanding of normal and abnormal GT development. The anatomy of the these three mutant mice confirms the importance of the androgen receptor, FGF-10 and Shh in genital development.

The impact of prenatal androgens on vaginal and urogenital sinus development in the female mouse

PURPOSE

In females abnormal urogenital virilization can occur secondary to prenatal exposure to exogenous or endogenous androgens. We studied the effects of different doses of prenatal androgens on urogenital sinus development and the location of the vaginal confluence in a mouse model.

MATERIALS AND METHODS

Timed pregnant C57/6 mice were exposed to 2, 5 and 10 mg testosterone propionate on gestational days 14 through 18. On gestational day 19 the genital tubercles and internal genitalia were examined grossly and histologically for the presence of virilization. Three-dimensional computer reconstruction was done and plastic cast injection molds of the urogenital sinus were made in select specimens.

RESULTS

Microscopic analysis confirmed the spectrum of virilization, which occurred in 98% of testosterone propionate treated female fetuses. Plastic cast injection showed that affected females had a longer urogenital sinus, more proximal confluence and shorter vagina in a dose dependent manner. Histological sections and 3-dimensional reconstruction revealed that the bladder neck moved proximal under the pubic bone, also in a dose dependent manner.

CONCLUSIONS

Prenatal exposure to increasing levels of androgen causes urogenital sinus elongation in a female mouse fetus. In the mouse model the confluence area moves proximally together with the bladder neck in a dose dependent manner.

Neuroanatomy of the male urethra and perineum

OBJECTIVE

To describe the topography of the perineal nerves from their pudendal origin to their course into the male genitalia, with specific attention on the course of the perineal nerve along the ventral penis, including branches into bulbospongiosus muscle and corpus spongiosum.

MATERIALS AND METHODS

The study comprised 18 normal human fetal penile specimens at 17.5-38 weeks of gestation (determined by fetal heel-to-toe length). Specimens were fixed in formalin, embedded in paraffin wax and serially sectioned at 6 micro m. The penile specimens contained the whole penis from the glans to the crural bodies, beneath the pubic arch and the perineum up to the anal verge. Immunocytochemistry was assessed on selected sections with antibodies against the neuronal markers S-100 and nitric oxide synthase (nNOS). Three-dimensional computer reconstruction of serial sections allowed an in-depth analysis of the neuroanatomy of the fetal penis, perineum and surrounding structures.

RESULTS

After the pudendal nerve leaves the pudendal canal it gives rise to the perineal nerve branches in the ischiorectal fossa. Perineal nerves travel alongside the ischiocavernous and bulbospongiosus muscles and before reaching the latter, nerve branches course into the bulbospongiosus muscle. During its pathway within this muscle, fine nerve fibres course into the corpus spongiosum by piercing through the junction of the muscle. At the penoscrotal area, the perineal nerves give branches to the scrotum, funnelling into the interscrotal septum. Perineal nerves continue their pathway over the ventral side of penis covering the ventral surface of corpus spongiosum. Branches of the dorsal nerve of the penis at the junction of corpus cavernosum and corpus spongiosum assemble into a network with the perineal nerves. All perineal nerves from their main trunk at the ischiorectal fossa until their interaction with dorsal nerve of penis at the base of penis were nNOS negative. After the interaction with the dorsal nerve of penis, they become nNOS positive.

CONCLUSION

Integrating neuroanatomical knowledge about the perineal nerves and their communication with the dorsal nerve of penis should facilitate a strategic approach to reconstructive procedures on the penis. Special care should be taken at the junction between the corpora cavernosa and spongiosa, where the dorsal nerve joins the perineal nerve, and at the proximal bulbospongiosus muscle, thereby protecting the fine nerves piercing into the cavernosa spongiosa.

Cellular and molecular mechanisms of development of the external genitalia

The limb and external genitalia are appendages of the body wall. Development of these structures differs fundamentally in that masculine development of the external genitalia is androgen dependent, whereas development of the limb is not. Despite this fundamental difference in developmental regulation, epithelial-mesenchymal interactions play key roles in the development of both structures, and similar regulatory molecules are utilized as mediators of morphogenetic cell-cell interactions during development of both the limb and external genitalia. Given the relatively high incidence of hypospadias, a malformation of penile development, it is appropriate and timely to review the morphological, endocrine, and molecular mechanisms of development of the genital tubercle (GT), the precursor of the penis in males and the clitoris in females. Morphological observations comparing development of the GT in humans and mouse emphasize the validity of the mouse as an animal model of GT development and validate the results of experimental studies. Accordingly, the use of mutant mice provides important insights into the roles of specific regulatory molecules in development of the external genitalia. While our current understanding of the morphological and molecular mechanisms of mammalian external genitalia development is still rudimentary, this review summarizes the current state of our knowledge and whenever possible draws from the rich experimental embryology literature on other relevant organs such as the developing limb. Future research on the hormonal and molecular mechanisms of GT development may yield strategies to prevent or reduce the incidence of hypospadias and to elucidate the molecular genetic mechanisms of GT morphogenesis, especially in relation to common organogenetic pathways utilized in other organ systems.

Urothlelium Facilitates the Recruitment and Trans-Differentiation of Fibroblasts into Smooth Muscle in Acellular Matrix

PURPOSE

Tissue engineering has shown promise for patients requiring bladder reconstruction secondary to diverse diseases such as spina bifida and tuberculosis. In this study we addressed whether urothelium in conjunction with an acellular bladder matrix is necessary for the recruitment of host cells to repopulate the graft and whether the urothelium facilitates trans-differentiation of host fibroblastic cells into bladder smooth muscle type cells.

MATERIALS AND METHODS

Urothelium from embryonic mice and rats (E18) was microdissected from bladder stroma after enzymatic digestion with 10 mM ethylenediaminetetraacetic acid. Acellular bladder matrix was prepared from postnatal day 1 rat and mouse pups using a combination of membrane disruption and DNA digestion. Urothelium was placed inside the bladder matrix and then grown either underneath the renal capsule or subcutaneously in athymic mice for 2 to 24 weeks. Grafts were sectioned and immunocytochemistry was performed with antibodies for alpha-actin smooth muscle, uroplakin, cytokeratins and vimentin to assess for the development of detrusor muscle.

RESULTS

Embryonic bladder urothelium resulted in ingrowth of fibroblasts into acellular matrix in greater than 85% of 60 grafts consisting of acellular matrix and bladder urothelium. Moreover, there was apparent trans-differentiation of these fibroblasts into a smooth muscle phenotype. This smooth muscle development occurred in a graded, incremental fashion starting as early as 3 weeks and resulting in almost complete repopulation of the matrix at 6 months.

CONCLUSIONS

These data support the hypothesis that epithelial mesenchymal signaling is important for the differentiation of bladder smooth muscle. Smooth muscle development during augmentation with acellular matrix is facilitated by the placement of epithelia onto the surface of the matrix.

Neuroanatomy of the ureterovesical junction: clinical implications

PURPOSE

The anatomy of the ureterovesical junction is germane to surgical reconstruction in patients with significant reflux. In this study we refine the description of the neuroanatomy of the distal ureter and ureterovesical junction.

MATERIALS AND METHODS

The distal ureter and bladder including the ureterovesical junction from 6 normal human fetuses (3 female and 3 male) at 21 to 40 weeks of gestation were studied using immunohistochemical analysis and 3-dimensional imaging techniques with antibodies against the nonspecific neuronal markers S-100 and nitric oxide synthase (nNOS).

RESULTS

Nerves were observed to occupy the medial aspect of the distal ureter. At the ureterovesical junction the nerves encircled the entire ureter. They traveled just outside Waldeyer's sheath, leaving a safe area for surgical dissection under the sheath. As the ureter tunneled into the bladder, the nerves localized to the lateral wall of detrusor muscle. The nerves originating from the ureter and bladder and innervating the trigonal area were immunoreactive to S-100 and nNOS. nNOS positive nerve fibers arising from the bladder and ureteral nerves were found spreading among the detrusor fibers in the trigonal area.

CONCLUSIONS

A detailed knowledge of the distal ureteral and ureterovesical junction neuroanatomy and the pathway of these nerves in relation to the anatomical landmarks is critical for preserving bladder function. Based on these anatomical dissections, we would recommend careful dissection within Waldeyer's sheath during ureteral reconstructive surgery.

Identification of communicating branches among the dorsal, perineal and cavernous nerves of the penis

PURPOSE

The mechanism of human erection requires the coordination of an intact neuronal system that includes the cavernous, perineal, and dorsal nerves of the penis. We defined the communication of these 3 nerves that travel under the pubic arch using specific neuronal immunohistochemical staining and 3-dimensional reconstruction imaging technique.

MATERIALS AND METHODS

A total of 18 normal human fetal penile specimens at 17.5 to 32 weeks of gestation were studied by immunohistochemical techniques. Serial sections were stained with antibodies raised against the neuronal markers S-100, and neuronal nitric oxide synthase (nNOS), vesicular acetylcholine transporter (VAChT), calcitonin gene-related peptide and substance P.

RESULTS

The continuation of the dorsal neurovascular bundle of the prostate was documented under the pubic arch. Two distinct nerve bundles were identified superior to the urethra and medial to the origin of the crural bodies. Nerve bundles were observed to join the corporeal bodies at the penile hilum. Proximal to the penile hilum the dorsal nerves stained only for S-100 and VAChT. From the junction of the crural bodies at the hilum to the glans penis dorsal nerve fibers stained positive for S-100, VAChT and nNOS. Calcitonin gene-related peptide and substance P demonstrated positive staining at the distal nerves, particularly at the glans. In contrast, the whole course of the cavernous nerve stained for S-100 and nNOS. Under the pubic arch at the penile hilum the cavernous nerves were found to convey nNOS positive branches to the dorsal nerve to transform its immunoreactivity to nNOS positive. Proximal nNOS negative perineal nerves were shown to stain positive for nNOS distal on the penis. Interaction between nNOS positive dorsal nerve branches and perineal nerves was at the cavernous-spongiosal junction, where the bulbospongiosus muscle terminates.

CONCLUSIONS

At penile hilum, where the corporeal bodies start to separate, the cavernous nerve sends nNOS positive fibers to join the dorsal nerve of the penis, thereby, changing the functional characteristics of the distal penile dorsal nerve. Similarly the nNOS negative, ventrally located perineal nerve originating from the pudendal nerve becomes nNOS reactive at the cavernous-spongiosal junction. These 2 examples of redundant neuronal wiring in the penis may impact erectile function, especially during reconstructive surgery.

The neuroanatomy of the human scrotum: surgical ramifications

OBJECTIVE

To define the scrotal nerve origin and distribution with respect to surrounding structures in male human fetuses, by using neuronal-specific markers and three-dimensional (3D) imaging techniques, as the developmental neuroanatomy of the human scrotum has not been studied in detail and an explicit description of nerve derivation and distribution in the human scrotum is germane to genital reconstructive surgery.

MATERIALS AND METHODS

Sixteen normal human fetal penile specimens at 17.5-38 weeks of gestation were studied. Specimens were fixed in formalin, embedded in paraffin wax, serially sectioned at 6 micro m and stained with the neuronal marker S-100. All of the specimens contained the whole penis and scrotum from glans to anal verge. The gestational age of the fetuses was determined by fetal heel-to-toe length. 3D-computer reconstruction of serial sections allowed a detailed analysis of the neuroanatomy of the fetal penis and scrotum.

RESULTS

The nerves innervating the ventral side of the proximal penis and scrotum originated mainly from the perineal nerves arising from pudendal nerves. The nerves travelling along the ventral side of penis coalesced at the penoscrotal area to be directed into the interscrotal septum. At the penoscrotal junction, nerves on both sides of the ventral penis shifted to the interscrotal septum in a triangular fashion. The interscrotal septum was densely occupied by nerve fibres. Nerves were distributed horizontally to both hemiscrotal walls through this interscrotal septum. Both hemiscrota seem primarily to be innervated separately.

CONCLUSION

The interscrotal septum has a dense innervation. Both hemiscrota were innervated mainly by horizontally distributed nerve fibres arising from the interscrotal septum. Any procedure violating the penoscrotal and interscrotal septal area may jeopardize scrotal innervation.

The outcome of bladder neck closure in children with severe urinary incontinence

PURPOSE

We evaluated the outcome of children who underwent bladder neck closure for the management of severe urinary incontinence.

MATERIALS AND METHODS

Bladder neck closure was performed in 12 patients with bladder exstrophy, 4 with myelomeningocele and 4 with urogenital sinus anomalies for severe urinary incontinence that persisted after multiple failed bladder outlet procedures. The effectiveness of bladder neck closure and the need for subsequent surgeries were ascertained.

RESULTS

Mean followup was 5.4 years (range 1 to 12). At 3 months after surgery 40% of the patients were completely dry, 20% had leakage via the stoma and 40% had a urethral fistula. After additional surgeries 85% of the patients were completely continent 2 years following bladder neck closure (15% declined further surgeries or had an ileal conduit). Of the 15 patients with followup longer than 3 years only 40% remained completely dry, and leakage via the stoma developed in 47% after being dry for 1 year. Repeat urodynamic studies did not show any adverse changes in bladder dynamics in the incontinent patients. Stomal stenosis occurred in 30% of the patients and bladder stones developed in 40%. None of the patients had hydronephrosis or bladder perforation. The early complication of fistula formation and the late development of leakage via the stoma appear to be related in part to compliance with intermittent catheterization.

CONCLUSIONS

Bladder neck closure is an effective method of achieving urinary continence in children in whom other bladder outlet surgery has failed. However, its success is dependent in part upon compliance with intermittent catheterization. Finally children who have undergone bladder neck closure are at an increased risk for stomal stenosis and bladder stones.

Surgical management of the neurogenic bladder and bowel

Spina bifida and myelodysplasia are associated with neurogenic abnormalities of the bladder and bowel function. All children with myelodysplasia require an evaluation of their urinary tract with ultrasound and urodynamics to confirm normal bladder and kidney function. Patients with anatomical and functional abnormalities require treatment, the mainstay being intermittent catheterization and anticholinergic medication. The treatment goals for patients with a neurogenic bladder are the preservation of the upper urinary tract, bladder and bowel continence, independence, autonomy, and facilitation of self-esteem. A minority of children will not respond to conservative therapy and will ultimately require surgical intervention. This review will discuss the surgical options for bladder augmentation, bladder neck reconstruction and closure, as well as the methods for the creation of continent catheterizable stomas. The timing, indications, and description for each procedure will be addressed. Finally, the antegrade continence enema procedure will be described for the management of refractory fecal incontinence.