Gastrocystoplasty: long-term followup

PURPOSE

Gastrocystoplasty is no longer favored at many institutions due to complications, including the hematuria-dysuria syndrome and metabolic alkalosis. We reviewed our experience to determine the advantages and disadvantages of bladder augmentation using stomach body wall.

MATERIALS AND METHODS

We retrospectively reviewed the medical records, urodynamic studies, x-rays and laboratory evaluations of 47 children who underwent gastrocystoplasty at our institution between 1986 and June 1997. Parents and patients were contacted by telephone for detailed interviews to validate the medical record and determine whether there had been any changes since the last visit. Followup ranged from 9 months to 11 years (mean 4.4 years). Bladder dysfunction was secondary to spinal dysraphism in 38 children. Other diagnoses included cloacal and bladder exstrophy, posterior urethral valves, a persistent urogenital sinus and bilateral ectopic ureters.

RESULTS

Preoperative and postoperative ultrasound studies available for 79 renal units demonstrated a stable or improved upper tract in 75 (95%). Preoperative and postoperative serum sodium, potassium and creatinine levels showed no significant changes. Mean serum chloride decreased 2.7 mEq./l. and bicarbonate increased 3.3 mEq./l. In the 3 patients with renal insufficiency serum bicarbonate increased 8 mEq./l. Mean pressure specific bladder volume at less than 20 cm. water increased 177 cc and mean maximum bladder pressure decreased from 35 to 13 cm. water. Two-thirds of the patients had bacilluria and a fourth reported a symptomatic bladder infection. No patients had bothersome mucus or required routine bladder irrigation. Symptoms consistent with the hematuria-dysuria syndrome were present in 27% of the patients. No patients had symptoms more than once weekly. Symptoms occurred in 75% of the patients without a neurogenic bladder, such as exstrophy or posterior urethral valves, and in 14% of those with neurogenic bladder dysfunction. In 1 case a bladder stone developed 8 years after surgery. Five patients required reoperation for complications related to gastrocystoplasty. No patient had perforation.

CONCLUSIONS

Our data show that even after a mean of 4.4 years gastrocystoplasty has significant advantages over intestinal augmentation, including decreased chloride reabsorption, mucous production and urinary infection, and an extremely low incidence of stones and perforation. The gastric patch is associated with metabolic alkalosis and the hematuria-dysuria syndrome, which may be avoided and medically treated with proper patient selection and close followup. The procedure should be avoided in sensate patients with sufficient bowel.

Length of stay for specialized pediatric urologic care

BACKGROUND

Pediatric urologic specialists have been excluded from many recent managed care contracts because they are believed to be more expensive and of no better quality than general urologists in managing common urologic problems in children. We believed this to be inaccurate.

OBJECTIVES

To compare the length of stay at the University of California, San Francisco Medical Center for 2 common pediatric urologic operative procedures with data from other northern California hospitals and to document our results and patient satisfaction.

DESIGN

Retrospective analysis of HCIA statewide database (HCIA Inc, Orange, Conn).

SETTING

Northern California, 1995.

SUBJECTS

Children younger than 12 years undergoing surgery for repair of an obstruction of the ureteropelvic junction or vesicoureteral reflux.

MAIN OUTCOME MEASURE

Length of stay.

RESULTS

The length of stay in our hospital was similar to that observed in other hospitals in which other full-time pediatric urologic specialists practiced and was significantly less than that observed in other northern California hospitals, even when adjusted for risk. In fact, a savings of 279 hospital days would have been realized if all patients had the same length of stay as that achieved at University of California, San Francisco Medical Center. In the 38 patients operated on at our center, there was uniform surgical success. Of the parents, 92% (11/ 12) were satisfied with their child's care and 92% (11/ 12) believed they received enough information to know what to expect and how to care for their child at home. There were no data available evaluating quality from other northern California hospitals for comparison.

CONCLUSIONS

Our finding that actual and risk-adjusted length of stay were shorter when patients were treated by full-time pediatric urologists, while excellent quality was maintained, suggests that these specialists achieve their results with more efficiency and lower resource utilization than do general urologists. The implication of these results is that exclusive contracting that prevents patients from receiving care from full-time specialists results in overuse of valuable resources and possibly reduced quality. If our results are generalizable, they have important implications for health care reform in the United States.

Gastrocystoplasty: is there a consensus?

The problems encountered with ileal and colocystoplasty have led to the use of the stomach for bladder augmentation, termed gastrocystoplasty. The advantages of gastrocystoplasty over intestinal segment augmentation include reduced chloride reabsorption, decreased mucus production, decreased urinary infection in the presence of acid urine, extremely low incidence of stones, and avoidance of complications from short bowel syndrome. The gastric patch provides comparable improvements in bladder volume, pressure, and continence. The thick muscular wall of the stomach facilitates ureteric reimplantation as compared with the small intestine, but the rate of stenosis and reflux may not be superior. The disadvantages of the gastric patch include complications of severe systemic alkalosis, which is usually manifest in dehydrated, renal compromised patients, and the hematuria-dysuria syndrome (HDS), which is more prevalent in patients with renal insufficiency, normal pelvic sensation, and urinary incontinence. The postoperative complication rate of gastrocystoplasty is comparable with that of other augmentation procedures and similarly warrants proper selection and close follow-up of patients. In this report we review the literature and present the results, including a discussion of the technique and the pathophysiology of its complications.

Mesenchymal-epithelial interactions in bladder smooth muscle development: epithelial specificity

PURPOSE

We previously showed that mesenchymal-epithelial interactions are necessary for the development of bladder smooth muscle. Specifically without bladder epithelium embryonic bladder mesenchyme does not differentiate into smooth muscle. We determine whether this process is specific to bladder epithelium or whether epithelial cells from other organ systems induce bladder mesenchyme to differentiate into smooth muscle, as well as whether epithelial age is an important variable.

MATERIALS AND METHODS

We recombined 14-day bladder mesenchyme before smooth muscle differentiation with rat epithelium from 14-day, 19-day, newborn and adult bladder, ureter, colon, ileum, stomach, cornea and epidermis. In addition, bladder epithelium was recombined with 14-day embryonic small intestinal, 14-day embryonic gastric and newborn seminal vesicle mesenchyme. All tissue recombinants were grafted under the renal capsule of an adult rat syngeneic host for 3 weeks.

RESULTS

Immunohistochemical analysis with antibodies directed against smooth muscle alpha-actin revealed that all epithelial types studied induced bladder mesenchyme to differentiate into smooth muscle, although to different degrees. Induction of smooth muscle was independent of urothelial age. In addition, bladder epithelium induced intestinal, gastric and seminal vesicle mesenchyme to differentiate into smooth muscle and express an overall morphological pattern indicative of the bladder fibromuscular wall.

CONCLUSIONS

The mechanism whereby urothelium induces bladder mesenchyme to differentiate into smooth muscle is not specific to embryonic urothelium. Older urothelium and heterotypic epithelium also induce smooth muscle differentiation. With the common use of bowel, stomach and ureteral segments for bladder augmentation it is important to understand the interaction of different types of epithelium with the native bladder.

Anatomical studies of hypospadias

PURPOSE

Hypospadias is the most common congenital anomaly affecting the penis. Successful repair depends on an accurate understanding of anatomy. We compared the anatomy of hypospadiac and normal fetal penises.

MATERIALS AND METHODS

A fetal penis at 33 weeks of gestation with distal shaft hypospadias was serially sectioned and compared to 10 normal human fetal specimens at 8 to 32 weeks of gestation. Immunohistochemical localization was performed with S-100 protein and protein gene product 9.5 to localize neurons. Blood vessels were localized by the presence of red corpuscles, and immunohistochemical staining with von Willebrand's factor and factor VIII. Three-dimensional computer reconstructions of the nerves, corporeal bodies, tunica and urethra of the hypospadiac and normal fetal penises were compared.

RESULTS

Except at the region of the abnormal urethral spongiosum and glans, the hypospadiac and normal penises showed no difference in neuronal innervation, corpora cavernosa and tunica albuginea architecture and blood supply. The nerves started proximally as 2 well defined bundles under the pubic rami superior and slightly lateral to the urethra. As the 2 crural bodies converged into the corpora cavernosa, the nerves diverged, spreading around the cavernous bodies up to the junction with the urethral spongiosum without remaining at the 11 and 1 o'clock positions. Along the entire shaft of the penis there were no neuronal structures at the 12 o'clock position. The most striking difference was in vascularity. In the hypospadiac penis factor VIII immunostaining revealed huge endothelial lined vascular channels filled with red blood cells. In contrast, the normal penis had well defined small capillaries around the urethra that fanned out into the glans. Vascularity was also extensive under the urethral plate. Nerve distribution in the abnormal glans was also less extensive than in the normal penis.

CONCLUSIONS

Increased knowledge of normal and hypospadiac penile anatomy with respect to the nerves, corporeal bodies, glans and vascularity is useful for the strategic design of penile reconstructive procedures.

Long-term benefits of early neurosurgery for lipomyelomeningocele

PURPOSE

Our previous experience with early neurosurgery for lipomyelomeningocele revealed that patients undergoing repair before age 1.5 years were more likely to have normal bladder function. We evaluate the durability of the urological benefits in patients with lipomyelomeningocele with longer followup.

MATERIALS AND METHODS

A retrospective chart review was performed on all patients who underwent urodynamic testing before and after primary neurosurgical repair of lipomyelomeningocele. A total of 43 patients presented between 1983 and 1995 with at least 12 months of followup (median 68, range 15 to 167).

RESULTS

Of the 43 patients 36 (84%) maintained stable clinical and urodynamic function, and 7 (16%) had late deterioration, which occurred between 9 months and 8 years postoperatively. Of 19 patients with normal urodynamic studies preoperatively 14 (74%) maintained normal function. Overall, 14 of 43 patients (33%) with lipomyelomeningocele had normal bladder and sphincter function during followup. The principal predictor of long-term normal bladder function was preoperative urodynamic status, since urodynamic studies were preoperatively normal in 13 of 14 patients (93%) who maintained normal bladder and sphincter function. Late neurosurgery was equally efficacious if urodynamic studies were normal.

CONCLUSIONS

Our data continue to support early diagnosis and neurosurgical intervention in patients with lipomyelomeningocele, since there is a higher likelihood of normal preoperative function that can be preserved. Furthermore, the results are durable in 84% of cases. However, close followup is necessary, since deterioration can occur up to 8 years postoperatively.

The correction of congenital penile curvature in young men

OBJECTIVE

To determine the long-term outcome of multiple parallel plication (MPP) used for correcting congenital penile curvature (with normal urethra and corpus spongiosum), a technique which takes account of the greater force of erection in young men (mean arterial pressure approximately 100 mmHg) than in neonates (approximately 60 mmHg).

PATIENTS AND METHODS

All young men who underwent surgical correction of congenital penile curvature using the multiple parallel plication technique between 1992 and 1995 were reviewed, from their charts and by a telephone survey.

RESULTS

Ten patients (mean age 22.3 years, SD 4, range 17-29) were identified, all of whom had been followed for more than one year (mean 2.8, SD 1.3, range 1.2-4.8). All 10 patients reported a preoperative curvature of 60-90 degrees; postoperatively, eight of the 10 patients had a successful outcome, based on self-documentation of a straighter penis (eight) and/or satisfactory intercourse (four). Two of these eight requested follow-up plications to correct a residual curvature of 15 degrees. All patients reported feeling the sutures as a small bump on the dorsal aspect of the penis. In one patient this was considered bothersome, but it did not interfere with intercourse. In one patient the curvature recurred 5 weeks after surgery, following intercourse. Another patient was lost to follow-up and could not be evaluated.

CONCLUSION

The MPP technique has the following advantages; it entails no dissection of the neurovascular bundle or corpus spongiosum of the tunica, avoiding complications (such as impotence and urethral injury) that may occur with manipulation of these structures; it can be performed under local anaesthesia and can be completed within 30 min; suture cut-through is unlikely because the dorsum (12 o'clock position) of the tunica albuginea is the thickest and hence strongest area of the corporal body; and the straightness of the penis can be determined easily because erection is sustained throughout the procedure. The disadvantages of the MPP technique are; several small bumps from the nonabsorbable sutures may be palpable, and the patient needs to be informed of this preoperatively: aspiration and phenylephrine injection may be required to prevent priapism.

Cellular signaling in the bladder

Embryologically, the urinary bladder is formed from endodermally derived epithelial cells and mesenchymal cells from the urogenital sinus and allantois. Experimentally, we have shown that bladder mesenchyme differentiates into bladder smooth muscle via an unknown signaling mechanism that originates from the urothelium. It is hypothesized that this signaling between the cellular types, occurs via growth factors. Evidence supporting this hypothesis is that a number of known growth factors, such as TGF beta 2 and 3, KGF and TGF alpha, as well as their receptors are regulated as a function of bladder development and are also modulated during experimental bladder outlet obstruction. Furthermore, growth factors most likely affect extracellular matrix degradative proteins which play a role in bladder remodeling during development, as well as in partial outlet obstruction. There is certainly impressive cellular communication that occurs during development and also occurs postnatally; such as during bladder injury. We have recently shown that KGF is directly responsible for the proliferation of urothelium during bladder injury. This normally quiescent cell, which in humans turns over once every six months to a year when injured, has the incredible ability to immediately proliferate covering the exposed areas of bladder muscle and submucosa. This proliferation is due to the direct effects of KGF, a classic paracrine growth factor which is secreted by the stromal compartment of the bladder and acts directly on the urothelium which harbors the receptor. The bladder also has an uncanny ability to regenerate. In a model to study the basic science behind bladder regeneration, a partial cystectomy was performed and an acellular tissue matrix devoid of all cellular elements was sutured to the defect. Within four days, the urothelium completely covered the acellular matrix, and within two weeks native smooth muscle was seen streaming into the acellular matrix in association with a new epithelium. It is hypothesized that cellular interactions between the epithelium and the mesenchyme, as we have shown in bladder differentiation, are encouraging the new growth of smooth muscle. For the bladder to be a safe and effective storage chamber the ideal cellular lining should be urothelium. Cells from the gastrointestinal are not optimal for this purpose since they either secrete or absorb electrolytes. We believe that the cellular interactions that occur between the urothelium and the foreign intestinal stroma will in time change the phenotype of the urothelium. Newer strategies for bladder replacement which take into account cellular signaling are critical for our young patients with neurogenic bladder disorders.

Surgical repair of urethral circumcision injuries

PURPOSE

The 2 types of urethral injury that can occur during circumcision are urethrocutaneous fistula and urethral distortion secondary to partial glans amputation. We report the surgical repair of these rare injuries.

MATERIALS AND METHODS

In 8 patients urethrocutaneous fistulas located on the distal penile shaft or at the coronal margin were managed by splitting the glans and using a Mathieu style skin flap in 4 or vascularized penile skin flap in 4 to bridge the urethral defect. Three patients underwent repair of a hypospadiac deviated urethra secondary to partial glans amputation by 1 cm. of urethral mobilization and repositioning the meatus into a terminal position within the remaining glans tissue.

RESULTS

The 8 patients with urethrocutaneous fistulas voided via a terminal meatus without fistula recurrence at a mean followup of 3.2 years (range 1 to 6). The 3 patients with partial glans amputation and urethral deviation repaired by short urethral advancement had functionally acceptable results, defined as a normal urinary stream, although 1 required meatal dilation postoperatively.

CONCLUSIONS

The 2 types of urethral injuries that can occur during circumcision are a subcoronal urethrocutaneous fistula and scarred abnormal urethra from partial glans amputation. The urethrocutaneous fistula can be successfully repaired by splitting the glans and forming a neourethra from a vascularized pedicle flap of penile skin. The abnormal urethra after partial glans amputation is more difficult to repair but repositioning the urethra in a more cosmetic location has restored function.

The effect of testosterone on androgen receptors and human penile growth

PURPOSE

Recent rat studies suggest that early exposure to exogenous testosterone accelerates the loss of androgen receptors and compromises eventual penile length. In humans we hypothesize that down regulation of the androgen receptor is not the mechanism that stops penile growth. To test this hypothesis we investigated the effects of androgen deprivation and supplementation on the developing human penis.

MATERIALS AND METHODS

A total of 15 normal human fetal penises at 7 to 19 weeks of gestation (mean plus or minus standard deviation 12 +/- 4.5) was divided in half sagittally. Specimens were grafted beneath the renal capsule of male athymic nude mice or nude rats. Three groups of host animals were prepared, including 10 with no testosterone that were castrated at grafting, 15 with testosterone and 5 with super testosterone in which 50 mg. testosterone propionate pellets were implanted subcutaneously at grafting. Each fetal penile specimen was its own control, since half was implanted into an intact animal and the other into a castrated or super testosterone host. Six weeks after grafting the specimens were analyzed for gross size (length), histology and expression of androgen receptors.

RESULTS

All human fetal penile specimens grew from the nadir size and appeared as white exophytic growths on the surface of the host kidneys. Normal grafts were larger than castrate specimens (mean 6.9 +/- 2.1 versus 3.9 +/- 2.1 mm., p = 0.014). Mean length of the super testosterone specimens (7.3 +/- 2.3 mm.) was not significantly greater than that of normal specimens (p = 0.797). Histological analysis revealed that all specimens were composed of viable penile tissue. Cellular density of the castrate penises was approximately 2 times greater than that of the normal and super testosterone specimens (40.6 +/- 5.9 versus 25.1 +/- 2.8 cells per cm.2, p > 0.001), as calculated on enlarged micrographs. Supraphysiological doses of testosterone did not change the histology compared to controls. Immunohistochemical localization revealed androgen receptors expressed throughout the corporeal bodies, surrounding stroma and penile skin with intracellular localization to nucleus. The mean proportion of cells expressing androgen receptors was higher in the castrate (29.4 +/- 5.2 cells per cm.2) than in the normal (24.0 +/- 3.7) and super testosterone (24.7 +/- 4.5) grafts (p = 0.005). However, in regard to growth there was no change in the proportion of androgen receptor positive cells among the groups.

CONCLUSIONS

Testosterone influences penile growth, possibly as a result of extracellular stromal expansion. The number of androgen receptor positive cells in the human fetal penis did not change among the castrate, normal and super testosterone hosts. These experiments support the hypothesis that penile growth cessation is mediated by mechanisms other than down regulation of the androgen receptor. Furthermore, these data support the hypothesis that early administration of androgen to prepubertal male individuals does not result in a shorter phallus in adulthood.

Development and regenerative ability of bladder in the transgenic epidermal growth factor receptor gene knockout mouse

PURPOSE

During embryogenesis we have previously shown that urothelium is essential for normal bladder growth and development. Urothelial growth may be mediated by peptides of the epidermal growth factor family, since the epidermal growth factor receptor is expressed in bladder urothelium and epidermal growth factor has been shown to induce deoxyribonucleic acid synthesis and migration of urothelial cells in vitro. Bladders from transgenic mice in which the epidermal growth factor receptor gene has been knocked out were used to examine the possible role of epidermal growth factor in bladder growth and development, detrusor neoformation and bladder regeneration.

MATERIALS AND METHODS

Whole bladders from transgenic knockout mice 0 to 10 days old were surgically implanted into the "subdetrusor" space of adult athymic nude rat hosts. After 10 days the dome of the host rat bladder was resected with the distal half of the transplanted knockout mouse bladder. Augmentation cystoplasty was then performed on the host rat bladder using acellular tissue matrix with a portion of the acellular matrix sutured directly to the transplanted knockout mouse bladder. The animals were sacrificed 2 or 3 weeks postoperatively. To test the ability of knockout bladder tissue to regenerate into the transplanted matrix species specific Hoechst dye was used to determine whether the cells within the acellular matrix were of host (rat) or transplant (knockout mouse) origin. Immunocytochemical analysis was used to assess muscle neoformation. Controls consisted of wild-type mouse bladders from the same litter. Since epidermal growth factor receptor knockout mice usually die in the neonatal period, the role of the epidermal growth factor receptor signaling pathway in long-term muscle development was evaluated by transplanting knockout and wild-type control bladders under the renal capsule of athymic nude mouse hosts. These mice were sacrificed 30 days later and muscle development was assessed using immunocytochemical analysis.

RESULTS

Histologically the transplanted acellular tissue matrix in the experimental and control animals appeared the same, containing well differentiated urothelial and smooth muscle cells that had migrated into the transplanted matrix. Staining with species specific Hoechst dye revealed that urothelial and smooth muscle cells transplanted from the knockout and wild-type mouse bladders invaded and regenerated in the transplanted matrix. There was no apparent difference in the amount of knockout or control mouse tissue in the transplanted matrix. Also, the long-term renal capsule transplants revealed no difference in the amount of smooth muscle in the epidermal growth factor receptor knockout and wild-type bladders.

CONCLUSIONS

Signaling through the epidermal growth factor receptor pathway is not necessary for normal bladder development or bladder regeneration after injury.

Smooth and striated muscle development in the intrinsic urethral sphincter

PURPOSE

The intrinsic urethral sphincter is composed of adjacent striated and smooth muscle. We studied the sequential expression of smooth and striated muscle proteins to gain insight into the ontogeny of intrinsic sphincter development.

MATERIALS AND METHODS

The intrinsic urethral sphincters of timed Fischer 344 rat embryos at 14, 16 and 18 days of gestation, neonates on postnatal day 1 and adult animals were examined. Serial sections of the urethra and adjacent levator ani muscles were studied histologically with hematoxylin and eosin, anti-alpha-smooth muscle actin, anti-alpha-sarcomeric actin and antistriated muscle myosin heavy chain antibodies.

RESULTS

The intrinsic urethral sphincter was identified within the periurethral mesenchyma as early as day 14 of gestation. Although striated myotubules were identified within the urethra by hematoxylin and eosin staining starting on postnatal day 1, striated muscle myosin heavy chain protein was absent in the embryonic and neonatal development of the sphincter, and it was expressed only in the mature myotubule of adults. alpha-Smooth muscle actin was expressed throughout the urethral sphincter of embryonic and neonatal animals. In adults alpha-smooth muscle actin was confined to the smooth muscle component of the urethra. Co-expression of alpha-smooth and alpha-sarcomeric muscle actin by the striated sphincter myotubule was noted only in neonates.

CONCLUSIONS

Development of the intrinsic urethral sphincter is characterized by sequential expression of well characterized muscle marker proteins. The co-expression of smooth and striated muscle markers by developing sphincter myotubule suggests the possibility that trans-differentiation of smooth to striated muscle occurs in the developing genitourinary tract.

Neurogenic bladder dysfunction due to myelomeningocele: neonatal versus childhood treatment

PURPOSE

We sought to determine whether the neonatal institution of treatment of neurogenic bladder dysfunction in myelomeningocele patients at high risk for urinary tract deterioration improves renal and bladder outcome.

MATERIALS AND METHODS

We reviewed the records of patients with bladder dysfunction believed to be at high risk for renal deterioration based on urodynamic studies. All patients were treated with clean intermittent catheterization. We compared rates of urinary infection, hydronephrosis, reflux, continence and surgical intervention in 46 patients in whom treatment was started in year 1 of life and 52 treated after age 4 years.

RESULTS

Renal outcome was similar in both groups with persistent hydronephrosis in 6 of 46 patients (13%) and 7 of 52 (14%), respectively. However, significantly fewer bladder augmentation procedures were required in patients started on treatment during year 1 of life (5 of 46, 11% versus 14 of 52, 27%, p < 0.05).

CONCLUSIONS

In addition to any psychological benefit, early intervention with clean intermittent catheterization in children with neurogenic bladder dysfunction may help to prevent irreversible bladder dysfunction and limit the need for bladder augmentation.

Growth factors in bladder wound healing

INTRODUCTION

Surgical and traumatic injuries to the bladder initiate a complex series of biological processes that result in wound healing. This process involves cellular proliferation, migration and differentiation; removal of damaged tissue; and production of extracellular matrix all of which may be controlled by growth factors. In skin, keratinocyte growth factor (KGF) is induced following incisional injury. We hypothesize that in bladder wound healing KGF and other growth factors are induced to modulate tissue repair.

METHODS

We have created a model of surgical bladder injury in the rodent. At 12, 24 and 48 hrs and 5 and 7 days after injury, the bladder was bisected and total RNA extracted from the anterior or wounded half and posterior or non-wounded half. Histological analysis of the bladder wound was performed with Mason's Trichrome and immunohistochemistry against smooth muscle alpha actin. RNase protection assays were performed to examine the expression of KGF, transforming growth factor (TGF)alpha and TGF beta 2 and 3 as well as the receptors for KGF and epidermal growth factor (EGF). Lastly, the effects of the exogenous administration of KGF on the bladder was tested on neonatal mice by daily injections of 5 micrograms KGF per gram body weight for 5 days.

RESULTS

At 12 hours after injury KGF mRNA expression in the anterior wounded bladder half and posterior non-wounded bladder half was 8 and 6 times higher respectively, compared to unoperated control bladders. A similar response was seen for TGF alpha, where the 12 hour mRNA expression was 4.5 times higher in the anterior wounded bladder half and 3.5 times higher in the posterior non-wounded bladder half compared to unoperated control bladders. The nadir mRNA expression for both KGF and TGF alpha occurred at 7 days after bladder injury and was the same as in unoperated control bladders. EGFR mRNA expression was approximately 2 times higher in both the anterior wounded and posterior non-wounded bladder halves compared to the nadir levels which occurred at 24 hours after injury. TGF beta 2 and beta 3 mRNA levels did not significantly change in either the anterior wounded or posterior non-wounded bladder halves. Exogenous KGF stimulation resulted in a marked urothelial proliferation when compared to age matched control animals.

CONCLUSION

During the early phases of bladder wound healing (12-24 hours post injury), mRNA for KGF and TGF alpha increased, whereas TGF beta 2 and beta 3 and the KGFR and EGFR remain unchanged. Additionally, exogenous KGF has a direct effect on urothelial proliferation. KGF and TGF alpha warrant further study as potential mediators of bladder wound healing.

Neuroanatomical ontogeny of the human fetal penis

OBJECTIVE

To determine the development of the human penis, and hence the cause of congenital anomalies, using an immunohistochemical analysis of fetal penile ontogeny.

MATERIALS AND METHODS

In 25 human fetal penile specimens (gestational age 8 to 23 weeks) various tissues were localized immunohistochemically using stains for alpha-actin (smooth muscle), cytokeratin 8 and 14 (epithelium) and protein gene-product (PGP) 9.5 (neurons).

RESULTS

Nerves were identified in the penis with anti-PGP in specimens of all ages, prominent dorsally at the 11 and 1 o'clock positions but also extending around the tunica to the junction of the corpus spongiosum and corpora cavernosa, suggesting that these structures may be injured in procedures which straighten the penis. The nerves continued into the glans on the dorsal aspect, suggesting that glans reduction in feminizing genitoplasties should be performed on the ventral aspect. Smooth muscle was first noted at 10 weeks' gestation, with epithelial differentiation occurring in the earliest specimens studied (8 weeks' gestation). With time, smooth muscle density was highest in the corpus spongiosum, especially between it and the corpora cavernosa. Smooth muscle also developed close to the urethral epithelium. The tunica albuginea showed consistent variations in thickness, with the mid-dorsal 12 o'clock position being the thickest, followed by the 5 and 7 o'clock periurethral positions.

CONCLUSION

A better knowledge of penile development and of the relationship of the nerves to the corpora cavernosa is useful in the strategic design of penile straightening procedures and feminizing genitoplasties.

The role of type IV collagenases in rat bladder development and obstruction

The role of type IV collagenases during rat bladder development and in response to partial bladder outlet obstruction was evaluated. Gelatinase gel zymography was performed on developing rat bladders (gestation d 16 and 19, at birth, 5, 10, 15, 20, 30, and 75 d postnatally), after partial obstruction of the bladder outlet in young adults and after separation of the epithelium from the mesenchyme in young adults. Bladder function was assessed by cystometry in obstructed animals. During development, the 72-kD type-IV collagenase [matrix metalloproteinase (MMP)-2, both latent and activated] was maximally expressed in the fetal period and decreased with age; whereas the 92-kD gelatinase (MMP-9) was not expressed in developing or adult bladders. MMP-2 was localized to the bladder mesenchyme and was undetectable in isolated epithelium. In 46 obstructed rats, there was an 8-fold increase in bladder volume and weight along with smooth muscle hypertrophy (mean smooth muscle cell diameter 7.09 +/- 0.11 microns versus 4.65 +/- 0.05 microns in normal animals, p < 0.001). Obstructed rats had increased quantities of latent and activated MMP-2 and MMP-9 compared with sham-operated and normal controls. These findings suggest that expression and activation of type IV collagenases (MMP-2 and 9) are developmentally regulated and play a role in bladder remodeling during developmental morphogenesis and after partial outlet obstruction.

Clean intermittent catheterization in boys using the LoFric catheter

PURPOSE

We compared a recently developed hydrophilic catheter to the standard polyethylene catheter in regard to hematuria, infection and patient satisfaction.

MATERIALS AND METHODS

A hydrophilic LoFric or standard Mentor catheter was assigned at random to 17 and 16 boys, respectively, who were skilled in intermittent self-catheterization. They were evaluated by weekly urinalysis and a questionnaire.

RESULTS

Significantly fewer episodes of microscopic hematuria occurred in the LoFric than Mentor catheter group (9 episodes in 6 subjects versus 19 episodes in 11, p < 0.05). There were also fewer episodes of bacteriuria in the LoFric group but the difference was not statistically significant. Mean scores plus or minus standard deviation on a visual analogue scale with 0 equal to most and 10 equal to least favorable were LoFric 3.3 +/- 2.8 versus Mentor 4.9 +/- 2.7 for catheter convenience and 2.7 +/- 2.4 versus 4.2 +/- 2.6 for insertion comfort, significantly favoring the LoFric group (p < 0.05 for both). Of the 16 LoFric subjects 13 preferred to continue its use, particularly those with a history of urethral trauma or sphincteric spasm.

CONCLUSIONS

In boys the LoFric catheter appears to cause less trauma. Although it is not reusable and is more expensive than the standard catheter, satisfaction is higher with the LoFric device and for select patients it has significant advantages.

Role of mesenchymal-epithelial interactions in normal bladder development

PURPOSE

To assess the role of cell-cell interactions in the development of bladder smooth muscle.

MATERIAL AND METHODS

Bladders from 14-day rat fetuses (prior to smooth muscle differentiation) were isolated and digested with trypsin to separate the mesenchyme and epithelium. Three types of specimens were prepared for grafting under the renal capsule of syngeneic adult hosts: a) intact bladder (BL) which had been isolated from fetuses of timed pregnant rats by surgical methods alone; b) bladder mesenchyme (BLM) alone (urothelium removed following trypsinization); and c) isolated BLM recombined with bladder urothelium (BLM + BLE). After 2 weeks of in vivo growth the grafts were assessed by immunocytochemical techniques for the expression of smooth muscle cells markers (actin, myosin, vinculin, laminin and desmin). The same experiments were repeated in vitro. In the final experiment, the induction of bladder smooth muscle was elicited in situ across species lines. Fourteen-day rat BLM was grafted onto the proximal ureter of an athymic nude mouse after ipsilateral nephrectomy.

RESULTS

Grafts of intact BL and BLM + BLE recombinants expressed smooth muscle differentiation. In contrast, grafts of BLM alone remained devoid of smooth muscle. This was also true for the in vitro studies in which, after 5 days of growth, BLM + BLE recombinants (n = 12) showed clear evidence of smooth muscle differentiation. In contrast, cultures of BLM alone (n = 12) exhibited poor growth without smooth muscle differentiation. In the final experiment testing the induction of smooth muscle across species, after 1 month in vivo growth the urothelium of the cut end of the ureter had invaded the grafted BLM. The BLM grafts (n = 3) had increased 30 times in size, and immunocytochemical staining showed clear expression of smooth muscle markers in the grafted BLM in proximity to the urothelium.

CONCLUSION

We have shown that the differentiation of smooth muscle in the rat bladder is dependent upon an inductive interaction with the epithelium.