A myogenic basis for the overactive bladder

OBJECTIVES

This article summarizes evidence supporting the conclusion that the spontaneous rises in pressure that occur in the overactive bladder, particularly in detrusor instability (DI), regardless of etiology, are myogenic.

METHODS

The evidence quoted has been obtained by several groups of investigators and includes electrophysiologic studies of detrusor myocytes, tension studies of strips of smooth muscle, in vivo experiments on animal models, and light and electron microscopic studies of the structure of the bladder wall.

RESULTS

The results of these studies demonstrate changes in the properties, structure, and innervation of the detrusor. These changes are consistent with the hypothesis that partial denervation of the detrusor may be responsible for altering the properties of the smooth muscle, leading to increased excitability and increased ability of activity to spread between cells, resulting in coordinated myogenic contractions of the whole detrusor.

CONCLUSIONS

It is suggested that alterations in the properties of the detrusor myocytes are a necessary prerequisite for the production of the unstable pressure rises seen in DI of any origin.

Decreased sensory receptors P2X3 and TRPV1 in suburothelial nerve fibers following intradetrusor injections of botulinum toxin for human detrusor overactivity

PURPOSE

Botulinum neurotoxin type A (BoNT/A) is effective in the treatment of intractable detrusor overactivity (DO). In addition to its known inhibitory effect on presynaptic release of acetylcholine by motor terminals, there is increasing evidence that BoNT/A may affect sensory fibers. We investigated a possible effect of BoNT/A on human bladder afferent mechanisms by studying the sensory receptors P2X3 and TRPV1 in biopsies from patients with neurogenic or idiopathic DO.

MATERIALS AND METHODS

A total of 38 patients (22 with neurogenic DO, 16 with idiopathic DO) with intractable DO were treated with intradetrusor BoNT/A, and bladder biopsies were taken at 4 and 16 weeks. Urodynamics and voiding diary were also recorded. Specimens were studied immunohistochemically for P2X3, TRPV1 and the pan-neuronal marker PGP9.5, in comparison with controls.

RESULTS

P2X3-immunoreactive and TRPV1-immunoreactive (-IR) fibers were decreased at 4 weeks after BoNT/A, and more significantly at 16 weeks (paired t test p=0.0004 and p=0.0008, respectively), when significant improvements were observed in clinical and urodynamic parameters. P2X3-IR fiber decrease was significantly correlated with reduction of urgency episodes at 4 and 16 weeks (p=0.0013 at 4 weeks and p=0.02 at 16 weeks), but not maximum cystometric capacity or detrusor pressures. TRPV1-IR fiber decrease showed a similar trend. PGP9.5-IR suburothelial fibers remained unchanged after treatment at both followups (p=0.85 and p=0.21 at 4 and 16 weeks, respectively). Urothelial cell P2X3-IR and TRPV1-IR also appeared unchanged.

CONCLUSIONS

Decreased levels of sensory receptors P2X3 and/or TRPV1 may contribute to the clinical effect of BoNT/A in detrusor overactivity.

A comparison between the response of patients with idiopathic detrusor overactivity and neurogenic detrusor overactivity to the first intradetrusor injection of botulinum-A toxin

PURPOSE

Several studies have shown that intradetrusor injections of botulinum neurotoxin type A (BoNT/A) may effectively treat intractable spinal neurogenic detrusor overactivity (NDO), but fewer reports exist on the use of BoNT/A in patients with idiopathic detrusor overactivity (IDO). The purpose of this study was to investigate whether comparable efficacy could be displayed in the response of patients with IDO to those with NDO.

MATERIALS AND METHODS

In a prospective, open label study, patients with urgency, and/or urgency incontinence due to urodynamically proven intractable detrusor overactivity received 300 units (NDO) or 200 units (IDO) of Botox injected into the bladder with a minimally invasive outpatient technique. Urodynamic maximum cystometric capacity and maximum detrusor pressure during filling, frequency of voids (frequency), number of incontinence episodes (leak) and number of voids associated with urgency per 24 hours (urgency) from 4-day voiding diaries were compared between the 2 groups at baseline and for changes at 4 and 16 weeks after treatment.

RESULTS

A total of 44 patients with spinal NDO and 31 with IDO were treated. At 16 weeks, mean +/- standard error maximum cystometric capacity increased from 229.1 +/- 24.8 to 427.0 +/- 26.9 ml, p <0.0001 in NDO and from 193.6 +/- 24.0 to 327.1 +/- 36.1 ml, p=0.0008 in IDO. Maximum detrusor pressure during filling decreased from 60.7 +/- 6.8 to 26.1 +/- 3.7 cm H2O, p <0.0001 in NDO and from 62.1 +/- 10.8 to 45.1 +/- 8.1 cm H2O, p=0.027 in IDO. Frequency decreased from 12.3 +/- 0.7 to 6.6 +/- 0.6 voids per 24 hours, p <0.0001 in NDO and from 13.6 +/- 1.1 to 8.3 +/- 0.7, p=0.0002 in IDO. Leak decreased from 3.9 +/- 0.5 to 0.7 +/- 0.2 incontinence episodes per 24 hours, p <0.0001 in NDO and from 3.2 +/- 0.8 to 0.6 +/- 0.3, p=0.0017 in IDO, and urgency decreased from 7.5 +/- 0.6 to 1.44 +/- 0.3 episodes per 24 hours, p <0.0001 in NDO and from 10.9 +/- 1.7 to 4.9 +/- 1.1, p <0.0001 in IDO. The 2 groups were comparable for baseline data, but percent improvement in urgency was greater in patients with NDO at 4 weeks (78.2% vs 56.3%, p=0.019) and 16 weeks (78.3% vs 50.7%, p=0.013). Of patients with NDO 69% required self-catheterization de novo posttreatment compared with 19.3% of those with IDO.

CONCLUSIONS

Patients with intractable IDO respond to intradetrusor BoNT/A with equally significant improvements in urodynamic and lower urinary tract symptom parameters as those with spinal NDO, despite the lower dose of toxin used.

Clinical efficacy and safety of tolterodine compared to oxybutynin and placebo in patients with overactive bladder

This study compared the clinical efficacy (determined from micturition diaries) and safety of 12 weeks' treatment with either tolterodine 2 mg twice daily, oxybutynin 5 mg three times daily or placebo in patients with an overactive bladder. A total of 277 patients were randomized and treated at 25 centers. Both tolterodine and oxybutynin significantly increased volume voided/micturition compared to placebo. Both treatment groups evoked greater decreases in micturitions per 24 hours and incontinence episodes per 24 hours compared to placebo; however, only tolterodine was significantly better than placebo in reducing micturition frequency. Tolterodine and oxybutynin were equivalent in their effectiveness. Tolterodine was significantly better tolerated than oxybutynin when adverse events (particularly frequency and intensity of dry mouth), dose reduction and patient withdrawals were considered. Oxybutynin is an effective drug whose frequent adverse effects limit its clinical usefulness. Tolterodine has equivalent efficacy to oxybutynin, but with less severe adverse effects. This will allow patients to receive more effective treatment for their condition, with better compliance.

P2X3-immunoreactive nerve fibres in neurogenic detrusor overactivity and the effect of intravesical resiniferatoxin

OBJECTIVES

The ATP-gated purinergic receptor P2X3 is expressed by small diameter sensory neurons and has been identified in normal and neurogenic human bladder suburothelial fibres. Animal models have shown that ATP is released by the urothelium during bladder distension, suggesting a mechanosensory role for P2X3 receptors in normal bladder function. Successful treatment of spinal neurogenic detrusor overactivity (NDO) with intravesical resiniferatoxin (RTX), which partly acts on suburothelial C fibres, provides evidence for the emergence of a C fibre-mediated spinal reflex. The aim of this study was to investigate the possible role of P2X3-positive innervation in this pathological voiding reflex by comparing suburothelial P2X3 immunoreactivity of controls and in patients with NDO before and after intravesical RTX.

METHODS

Bladder biopsies were obtained from 8 controls and 20 patients with refractory NDO enrolled in a trial of intravesical RTX. P2X3 nerve fibre density and intensity were studied in the specimens by immunohistochemistry.

RESULTS

P2X3-IR nerve fibres were significantly increased in patients with NDO compared to controls (p=0.014). Thirteen patients had pre- and post-RTX biopsies available for immunohistochemistry; 5 of them responded clinically and 8 were non-responders. In the 5 patients who responded to RTX, there was a significant decrease in P2X3-positive fibres (p=0.032), whereas in non-responders, P2X3-IR nerve fibre density did not change significantly.

CONCLUSIONS

In patients with NDO, the numbers of P2X3-IR nerve fibres were increased in the suburothelium. There was a significant decrease in P2X3 immunoreactivity in responders to RTX, indicating a potential pathophysiological role for the P2X3 expressing fibres.

Histological changes in the urothelium and suburothelium of human overactive bladder following intradetrusor injections of botulinum neurotoxin type A for the treatment of neurogenic or idiopathic detrusor overactivity

BACKGROUND

We examined, for the first time in a prospective study, the histological changes in the urothelium and suburothelium of patients with neurogenic (NDO) or idiopathic detrusor overactivity (IDO) after one or repeat treatments with intradetrusor BoNTA.

METHODS

Flexible cystoscopic bladder biopsies were obtained from patients with urodynamically proven intractable spinal NDO or IDO before and 4 and 16 wk after one or repeat treatments with intradetrusor injections of BOTOX1 (NDO 300 U, IDO 200 U). Specimens were stained for haematoxylin-eosin and analysed blindly for inflammatory changes, fibrosis, hyperplasia, and dysplasia in the urothelium and suburothelium. Statistical comparisons were significant at p values less than 0.05.

RESULTS

Signs of chronic inflammation were found in 59.1% of baseline biopsies (65.6% of NDO vs. 50% of IDO, p=0.049), 67.6% of post-first biopsies and 86.4% after repeat injections. The two groups were comparable for degree of baseline inflammation, which did not change significantly after first injection and up to 16 wk after a third injection. Mild fibrosis was found in 2.2% of biopsies examined, equally before and after treatment, but not after repeat injections. No dysplasia or hyperplasia was identified. Eosinophils were identified more frequently in biopsies taken after repeat injections compared with the post-first injection and baseline biopsies (chi2=8.23, p=0.018). No difference existed between NDO and IDO bladders.

CONCLUSIONS

BoNTA injections do not appear to be producing significant inflammatory changes, fibrosis, or dysplastic changes in human bladder urothelium/suburothelium after a single injection and in a limited number of repeat treatment biopsies. The presence of eosinophils might be treatment-related, because they were mostly found in post-treatment biopsies.

Time dependent changes in diabetic cystopathy in rats include compensated and decompensated bladder function

PURPOSE

Diabetic bladder dysfunction is among the most common and bothersome complications of diabetes mellitus. While bladder filling and voiding problems have been reported, the precise functional changes in diabetic bladders remain unclear. We investigated time dependent changes in bladder function in streptozotocin induced diabetic rats.

MATERIALS AND METHODS

Cystometrograms and detrusor muscle contractility were examined in male age matched control and diabetic Sprague-Dawley rats (Harlan, Indianapolis, Indiana) 3, 6, 9, 12 and 20 weeks after diabetes induction with streptozotocin.

RESULTS

Diabetes decreased average body weight and increased bladder weight, capacity and compliance. Peak detrusor leak pressure increased gradually from weeks 3 to 6 to 9 in diabetic rats (mean +/- SEM 47.3 +/- 2.5, 50.8 +/- 3.0 and 56.0 +/- 3.6 cm H(2)O) and in controls (36.9 +/- 1.4, 37.7 +/- 1.5 and 41.6 +/- 1.81 cm H(2)O, respectively). However, at 12 and 20 weeks diabetic rats deviated strongly from this trend with peak detrusor leak pressure decreasing vs controls (41.6 +/- 2.8 and 37.3 +/- 0.9 vs 45.2 +/- 1.7 and 49.6 +/- 1.4 cm H(2)O, respectively) and post-void resting pressures increasing from 9-week levels vs controls (interactions p <0.0001). In contractility studies increased contractile force responses of diabetic animals to carbamylcholine chloride, potassium chloride, adenosine 5'-triphosphate and electric field stimulation peaked at 6 or 9 weeks but at 12 to 20 weeks they generally reverted toward those of controls (carbamylcholine chloride and electrical field stimulation interactions p = 0.0022 and 0.01, respectively).

CONCLUSIONS

Diabetic bladders may undergo a transition from a compensated to a decompensated state and transition in the streptozotocin rat model may begin 9 to 12 weeks after induction.

Increased nerve growth factor expression triggers bladder overactivity

Prior studies have demonstrated an association between visceral inflammation, an increase in nerve growth factor (NGF) expression, and development of hyperalgesia. Because multiple mediators are released during inflammatory processes, we examined the effect of NGF alone using viral gene transfer in vivo. Replication-deficient adenoviral vectors encoding for NGF or beta-galactosidase were injected into the bladder wall. NGF levels were determined with an enzyme-linked immunoabsorbance assay. Cystometrograms were obtained 3 and 5 days after gene transfer by using a surgically implanted bladder catheter in awake male rats. Although the treatment with a control virus did not change NGF levels compared with those of naive animals, the vector encoding for NGF increased NGF protein levels in the bladder 4-fold. Histologically, no evidence of inflammation was noted. Expression of NGF led to bladder overactivity, whereas beta-galactosidase expression was without effect. These data demonstrate that a transient increase in NGF expression without associated inflammation sensitizes visceral reflex pathways, leading to bladder overactivity. Treatment strategies targeting NGF signaling might be useful in disorders involving sensitization of peripheral nerves.

PERSPECTIVE

Growth factors have been implicated in the pathogenesis of inflammatory pain. This study uses gene transfer to demonstrate that NGF sensitizes afferent pathways in the absence of inflammation, making it a potentially relevant treatment target.

Bladder wall abnormalities in myelodysplastic bladders: a computer assisted morphometric analysis

Myelodysplasia represents the most common cause of neurogenic bladder dysfunction in children. The specific histological features associated with myelodysplastic bladders have not been previously characterized. Our objective was to study the relationship between smooth muscle and connective tissue in control and myelodysplastic bladders using classical morphometric analysis with the assistance of an automated image analysis system. Gross histological analysis of the bladder specimens of normal stillborn fetuses showed organized muscle bundles embedded in a small amount of connective tissue. The bladder specimens of myelomeningocele stillborn fetuses showed a marked paucity of muscle bundles as well as a significantly diminished size of the muscle bundles. The myelomeningocele bladder specimens obtained from patients undergoing autopsy and those undergoing augmentation cystoplasty revealed significant interfascicular and pericellular infiltration of the smooth muscle by dense connective tissue. Quantitative morphometric analysis showed that the myelomeningocele stillborn fetuses have a significant increase in the volumetric content of connective tissue compared to control stillborn fetuses. The bladders of myelomeningocele patients who underwent autopsy or augmentation cystoplasty had a 3-fold increase in connective tissue when compared to normal controls. These findings reveal that structural changes in the histological components of the myelodysplastic bladder can be demonstrated not only in patients of varying ages undergoing autopsy or augmentation cystoplasty but also in the developing fetus. These findings enhance our understanding of the relationship of connective tissue proliferation to smooth muscle in the myelodysplastic bladder. We discuss the relationship of these findings to pathological detrusor morphology and detrusor dysfunction.

Pediatric robotic-assisted laparoscopic augmentation ileocystoplasty and Mitrofanoff appendicovesicostomy: complete intracorporeal--initial case report

INTRODUCTION

To the best of our knowledge, we report the first case of complete intracorporeal robotic-assisted laparoscopic augmentation ileocystoplasty and Mitrofanoff appendicovesicostomy in a pediatric patient, outlining the surgical technique and short-term results.

TECHNICAL CONSIDERATIONS

The operative steps of the open procedure were replicated laparoscopically using robotic-assistance. In brief, 5 transperitoneal laparoscopic ports were placed before docking the da Vinci S robotic system. A 20-cm ileal segment was isolated, and the gastrointestinal anastomosis was performed in an end-to-end fashion using intracorporeal suturing. The appendix was anastomosed to the right posterior wall of the bladder over an 8F feeding tube in an extravesical fashion. The bladder was incised in a coronal plane, and the simple ileal on-lay patch was anastomosed to the posterior and anterior walls of the bladder. A suprapubic catheter and pelvic drain were placed, and the Mitrofanoff stoma was then fashioned. Cystography was performed at 4 weeks postoperatively.

CONCLUSIONS

This preliminary first successful report suggests that robotic-assisted ileocystoplasty and appendicovesicostomy is feasible. A reasonable outcome with early recovery, resumption of normal activities, and excellent cosmesis can be achieved in selected patients. However, whether a robotic-assisted approach provides any significant advantages over conventional open procedures is yet to be determined with a large case series.

Characterization of Neuropathic Bladder Smooth Muscle Cells in Culture

PURPOSE

Clinically bladder cells used in tissue engineering techniques will come from neuropathic bladders and not normal bladders. We determined if neuropathic bladder smooth muscle (SM) cells (SMCs) retain functional differences when cultured in vitro.

MATERIALS AND METHODS

Primary cultures of SMCs were established from patients with a neuropathic bladder (5) and a normal bladder (5). Expression of alpha-SM actin and SM myosin heavy chain was determined using immunocytochemical staining and Western blot analysis. Baseline cell proliferation and the mitogenic response to angiotensin II was assessed by cell counting and cell viability assays. Cell contractility was determined for normal and neuropathic SMCs using an in vitro collagen lattice assay. Cell adherence was measured assessed using partial and complete trypsinization assays.

RESULTS

Normal and neuropathic SMCs showed similar morphology in culture, and similar patterns of alpha-SM actin and SM myosin expression. Following 10 days of plating under optimal growth conditions the number of neuropathic SMCs was 170% more than normal SMCs. In response to angiotensin II neuropathic SMCs reached 54% of maximal growth capacity as opposed to 30% for normal SMCs (p <0.01). Neuropathic SMCs contracted significantly less in 10% serum and calcium ionophore (p <0.05), as determined by in vitro contractility assays. Neuropathic SMCs had 19% and 30% less adherent cells than normal SMCs (p <0.01) following isotonic solution washes and trypsinization, respectively.

CONCLUSIONS

These results demonstrate that cultured neuropathic bladder SMCs possess and maintain different characteristics than normal SMCs in vitro. The potential clinical implications of using these cells in conjunction with tissue engineering techniques for the promotion of bladder regeneration requires further investigation.

Brainstem in multiple system atrophy: clinicopathological correlations

1. Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder that manifests with parkinsonism, cerebellar ataxia, and autonomic failure in various combinations. 2. Orthostatic hypotension, neurogenic bladder, laryngeal stridor and sleep apnea, and rapid eye movement (REM) sleep behavior disorder are prominent manifestations of MSA. 3. In MSA, there is severe depletion of catecholaminergic neurons of the C1 and A1 areas in the ventrolateral medulla, and this may contribute to orthostatic hypotension and endocrine disturbances in this disorder, respectively. 4. Loss of corticotrophin-releasing factor (CRF) neurons in the pontine micturition area may contribute to neurogenic bladder dysfunction. 5. Respiratory abnormalities may reflect loss of cholinergic neurons in the arcuate nucleus of the ventral medulla. 6. Loss of cholinergic mesopontine neurons, in the setting of loss of locus ceruleus neurons and preservation of rostral raphe neurons, may contribute to REM sleep abnormalities in MSA.

M2 receptors in genito-urinary smooth muscle pathology

In vitro bladder contractions in response to cumulative carbachol doses were measured in the presence of selective muscarinic antagonists from rats which had their major pelvic ganglion bilaterally removed (denervation, DEN) or from rats in which the spinal cord was injured (SCI) via compression. DEN induced both hypertrophy (505+/-51 mg bladder weight) and a supersensitivity of the bladders to carbachol (EC50=0.7+/-0.1 uM). Some of the SCI rats regained the ability to void spontaneously (SPV). The bladders of these animals weighed 184+/-17 mg, significantly less than the bladders of non voiding rats (NV, 644+/-92 mg). The potency of carbachol was greater in bladder strips from NV SCI animals (EC50=0.54+/-0.1 uM) than either bladder strips from SPV SCI (EC50=0.93+/-0.3 microM), DEN or control (EC50=1.2+/-0.1 microM) animals. Antagonist affinities in control bladders for antagonism of carbachol induced contractions were consistent with M3 mediated contractions. Antagonist affinities in DEN bladders for 4-diphenlacetoxy-N-methylpiperidine methiodide (4-DAMP, 8.5) and para fluoro hexahydrosilodifenidol (p-F-HHSiD, 6.6); were consistent with M2 mediated contractions, although the methoctramine affinity (6.5) was consistent with M3 mediated contractions. p-F-HHSiD inhibited carbachol induced contraction with an affinity consistent with M2 receptors in bladders from NV SCI (pKb=6.4) animals and M3 receptors in bladders from SPV SCI animals (pKb=7.9). Subtype selective immunoprecipitation of muscarinic receptors revealed an increase in total and an increase in M2 receptor density with no change in M3 receptor density in bladders from DEN and NV SCI animals compared to normal or sham operated controls. M3 receptor density was lower in bladders from SPV SCI animals while the M2 receptor density was not different from control. This increase in M2 receptor density is consistent with the change in affinity of the antagonists for inhibition of carbachol induced contractions and may indicate that M2 receptors or a combination of M2 and M3 receptors directly mediate smooth muscle contraction in bladders from DEN and NV SCI rats.

Electrical stimulation for the treatment of bladder dysfunction: current status and future possibilities

Electrical stimulation of peripheral nerves can be used to cause muscle contraction, to activate reflexes, and to modulate some functions of the central nervous system (neuromodulation). If applied to the spinal cord or nerves controlling the lower urinary tract, electrical stimulation can produce bladder or sphincter contraction, produce micturition, and can be applied as a medical treatment in cases of incontinence and urinary retention. This article first reviews the history of electrical stimulation applied for treatment of bladder dysfunction and then focuses on the implantable Finetech-Brindley stimulator to produce bladder emptying, and on external and implantable neuromodulation systems for treatment of incontinence. We conclude by summarizing some recent research efforts including: (a) combined sacral posterior and anterior sacral root stimulator implant (SPARSI), (b) selective stimulation of nerve fibers for selective detrusor activation by sacral ventral root stimulation, (c) microstimulation of the spinal cord, and (d) a newly proposed closed-loop bladder neuroprosthesis to treat incontinence caused by bladder overactivity.

Surgical results in patients with tuberculosis of the spine and severe lower-extremity motor deficits: a retrospective study of 48 patients

Object

Significant numbers of patients with spinal tuberculosis (TB), especially in developing countries, still present late after disease onset with severe neurological deficits. The authors conducted a study to assess the outcome in these patients.

Methods

Fifty-nine patients with spinal TB and severe motor deficits underwent surgery at the authors' center during the past 10 years. Data obtained in 48 patients with a minimum of 3 months of follow up (mean follow-up period 12.8 months) were analyzed. The disease in 34 patients was characterized by Frankel Grade A/B (Medical Research Council Grade 0/5) and in 14 patients by Frankel Grade C (unable to walk even with support) at admission. Thirty (88%) of the 34 patients with Frankel Grade A/B status and 13 (92.8%) of the 14 patients with Frankel Grade C status at admission experienced improvement to Frankel Grade D/E (walking with or without support) at the last follow-up examination 3 or more months after surgery. The degree of improvement exhibited by patients with a Frankel Grade A/B spinal cord injury was comparable to that shown by patients with Frankel Grade C status. Even patients with flaccid paraplegia, gross sensory deficit, prolonged weakness, spinal cord signal changes demonstrated on magnetic resonance imaging, and bladder involvement have experienced dramatic improvement in motor function since surgery. A significant number of the patients have shown remarkable improvement in other symptoms such as pain (91.6%), spasticity (88%), and bladder symptoms (88%).

Conclusions

A significant proportion of patients with spinal TB and severe motor deficits experience remarkable improvement after surgical decompression and hence should undergo surgery even though they may be suffering from paraplegia of considerable duration.

Ureterocystoplasty: the 'bladder' augmentation of choice

OBJECTIVE

To reduce the complications of enterocystoplasty by augmenting the bladder with a megaureter.

PATIENTS AND METHODS

Ureterocystoplasty was performed in eight children aged 20 months-15 years. Three had impaired renal function and three were in established chronic polyuric renal failure.

RESULTS

The seven older children were dry by day with clean intermittent catheterization and the youngest, at the age of 3 1/2 years, had a dry interval of 2 h after catheterization. The three children with polyuric renal failure required nocturnal catheterization or were wet at night. The post-operative urodynamics showed a significant improvement in all cases with abolition of detrusor instability in seven patients and a reduction in end filling pressure. Bladder volume increased from a mean of 100 ml (range 45-215) to 311 ml (range 150-450) (P = 0.01). There was no deterioration in renal function.

CONCLUSION

The early results of ureterocystoplasty compare favourably with those of enterocystoplasty without the risks of long-term metabolic and neoplastic complications.

Anorectal and bladder function after sacrifice of the sacral nerves

STUDY DESIGN

The quantitative changes in anorectal and bladder functions after sacrifice of the sacral nerves were assessed.

OBJECTIVES

To evaluate the bladder and anorectal functions before and after sacral nerve division in patients with sacral bone tumors.

SUMMARY OF BACKGROUND DATA

The quantitative changes in bladder and anorectal functions after sacrifice of the sacral nerves have not been intensively studied. The purpose of this investigation was to measure the bladder and anorectal function before and after sacral nerve division using manometry and cystometry.

METHODS

Surgical resection of a sacral tumor was performed in five patients. The sacral nerves were sacrificed bilaterally in three patients and unilaterally in two patients. Anorectal function was evaluated on the basis of symptoms and physiologic tests. Micturition function was evaluated based on symptoms, and intravesical pressures were measured by cystometry.

RESULTS

The two patients with unilateral sacral nerve loss did not experience subjective problems with defecation or micturition, although the residual volume of urine was increased after surgery. Two of the three patients with bilateral sacral nerve loss had no urge to defecate, were unable to differentiate between feces and flatus, and experienced no urgency. Fecal incontinence was uncommon because of firm feces. It was possible to control defecation using enemas on alternate days. The third patient underwent colostomy because the maximum resting pressure, which is controlled by the hypogastric nerves, was affected before surgery.

CONCLUSION

Unilateral sacrifice of sacral nerves results in little bladder or anorectal dysfunction.

Trigonal injection of botulinum toxin-A does not cause vesicoureteral reflux in neurogenic patients

AIMS

We evaluated the effect of botulinum toxin type A (BTX-A) injections in the trigone on the antireflux mechanism and evaluated its short-term efficacy.

MATERIALS AND METHODS

Between April and December 2006, 21 patients (10 men and 11 women) were prospectively evaluated. All were incontinent due to refractory NDO and underwent detrusor injection of 300 units of BTX-A, including 50 units into the trigone. Baseline and postoperative evaluation after eight weeks included cystogram, urinary tract ultrasound and urodynamics.

RESULTS

At baseline, 20 patients had no vesicoureteral (VUR) and one had grade II unilateral VUR. Postoperative evaluation revealed no cases of de novo VUR and the patient with preinjection VUR had complete resolution of the reflux. Ultrasound showed 5 (23.8%) patients with hydronephrosis before BTX-A injection and only one (4.8%) at the followup evaluation (p=0.066). After treatment, 9 (42.8%) patients became dry, 11 (52.4%) were improved and one (4.8%) had no improvement. Improved patients received antimuscarinic treatment and 8 (38.1%) became dry, with a final total continence rate of 80.1%. Cystometric capacity increased from 271+/-92 to 390+/-189 ml (p=0.002), reflex volume varied from 241+/-96 to 323+/-201 ml (p=0.020) and maximum detrusor pressure reduced from 66+/-39 to 38+/-37 cm H(2)O (p<0.001).

CONCLUSIONS

Our results confirm the safety of trigone injections of BTX-A in terms of development of VUR and upper urinary tract damage. Whether they are beneficial for patients with NDO or other causes of voiding dysfunction will need further studies.

Bladder cancer in patients with spinal cord injury

OBJECTIVE

The incidence of bladder cancer in spinal cord injury (SCI) is 16 to 28 times higher than that in the general population. The objective of this study was to investigate the characteristics of bladder cancer that are unique to the SCI population.

DESIGN

Retrospective review.

METHODS

The charts of 16 patients diagnosed with bladder cancer from 1982 to 2001 were reviewed for type of cancer, exposure to risk factors, presenting symptoms, and survival time.

RESULTS

The presenting manifestations were gross hematuria in 14 patients, papillary urethral growth in 1 patient, and acute obstructive renal failure in 1 patient. The diagnosis was made on initial cystoscopic evaluation in 16 patients; 3 patients required further evaluation. Eight of the 11 screening cytologies were suspicious for a malignancy prior to the diagnosis. Seven patients had transitional cell carcinoma, 6 patients had squamous cell carcinoma (SCCA), and 3 patients had both. The bladder wasmanaged with chronic indwelling catheter in 12 patients. Nine patients died of bladder cancer metastases and the remaining 3 patients died of other causes. Six patients survived 5 years or more; 4 were still alive at the completion of this study.

CONCLUSION

Gross hematuria in individuals with SCI warrants aggressive assessment for bladder cancer. Chronic indwelling catheter, smoking, and renal and bladder stones are important risk factors for cancer. The incidence of SCCA in the SCI popullation is much higher than in the general population. Cystoscopic and cytologic evaluation in patients with advanced disease may fail to confirm the diagnosis in a high proportion of patients.

Quantification of bladder smooth muscle orientation in normal and spinal cord injured rats

Spinal cord injuries (SCI) often lead to severe bladder dysfunctions. Our previous studies have demonstrated that following SCI, rat bladder wall tissue became hypertrophied, significantly more compliant, and changed its mechanical behavior from orthotropic to isotropic. In order to elucidate the link between the tissue microstructure and mechanical properties of the wall, we have developed a novel semi-automated image analysis method to quantify smooth muscle bundle orientation and mass fraction in the bladder wall tissues from normal and 10 day-post-SCI rats. Results of the present study revealed that there were significant (p < 0.05) increases in smooth muscle area fractions as well as significantly (p < 0.001) fewer cell nuclei per muscle area in the SCI groups compared to the normal groups. Furthermore, while the normal rat bladders exhibited predominant smooth muscle orientation only in the longitudinal direction, the SCI rat bladders exhibited smooth muscles oriented in both the circumferential and longitudinal directions. These results provide first evidence that bladder smooth muscle cells exhibit hypertrophy rather than hyperplasia and developed a second, orthogonal orientation of smooth muscle bundles following SCI. The results of the present study corroborate our previous mechanical anisotropy data and provide the basis for development of structure-based constitutive models for urinary bladder wall tissue.

Myogenic bladder decompensation in boys with a history of posterior urethral valves is caused by secondary bladder neck obstruction?

OBJECTIVE

To investigate whether myogenic bladder decompensation in patients treated for congenital posterior urethral valves (PUV, the most serious cause of infravesical obstruction in male neonates and infants) may be secondary to bladder neck obstruction, as despite prompt ablation of PUV these patients can have dysfunctional voiding during later childhood or adolescence, the so-called 'valve bladder syndrome'.

PATIENTS AND METHODS

The study comprised 18 boys (mean age 14 years, range 6.2-18.5) who had had successful transurethral ablation of PUV between 1982 and 1996, and had completed a follow-up which included serial assessment of serum creatinine, completion of a standard voiding diary, ultrasonography with measurement of urine before and after voiding, a urodynamic examination with simultaneous multichannel recording of pressure, volume and flow relationships during the filling and voiding phases, coupled with video-cystoscopy at least twice. The mean (range) follow-up was 9.3 (6-17) years.

RESULTS

Urodynamic investigation showed myogenic failure with inadequate bladder emptying in 10 patients; five with myogenic failure also had unstable bladder contractions. On video-cystoscopy the posterior bladder neck lip appeared elevated in all patients but in those with myogenic failure it was strongly suggestive of hypertrophy, with evidence of obstruction. At the last follow-up one patient with myogenic failure who had had bladder neck incision and four others who were being treated with alpha-adrenergic antagonists had a significant reduction of their postvoid residual urine.

CONCLUSION

Despite early valve ablation, a large proportion of boys treated for PUV have gradual detrusor decompensation, which may be caused by secondary bladder neck obstruction leading to obstructive voiding and finally detrusor failure. Surgical or pharmacological intervention to improve bladder neck obstruction may possibly avert this course, but further studies are needed to validate this hypothesis.

Differentially expressed gene networks in cultured smooth muscle cells from normal and neuropathic bladder

Neuropathic bladder dysfunction results from abnormal development of the spine, spinal cord injuries, or diseases such as diabetics. Patients with neuropathic bladders often require surgical intervention such as bladder reconstruction to improve incontinence and prevent renal damage. Tissue engineering with ex-vivo cultured bladder cells has been suggested as one means for improving bladder function. However, we previously demonstrated that cultured bladder smooth muscle cells (SMCs) derived from neuropathic bladder exhibit and maintain altered pathologic phenotypes in culture. To identify genes that are responsible for the abnormal neuropathic phenotypes specifically elevated cell proliferation, the expression levels of 1,185 genes were compared between cultured SMCs derived from normal and neuropathic bladders using a cDNA array consisting of well-annotated genes. The expression data were analyzed using several methods to identify differentially expressed genes. The resulting sets of differentially expressed genes were examined by pathway analysis to identify the networks that remain abnormal in the culture-stable phenotype of neuropathic SMCs. A total of 18 genes that are differentially expressed between cultured normal and neuropathic bladder SMCs were identified. Of these 17 were up-regulated greater than 2-fold in neuropathic bladder SMCs, six of them along with one gene that was not up-regulated greater than 2-fold in cultured neuropathic bladder SMCs were confirmed and identified by more stringent analysis methods including significance analysis of microarrays, class comparison, and class prediction analyses. The major dysregulated pathways include fibroblast growth factor signaling, PTEN signaling, and integrin signaling. Our results further suggest that altered neuropathic bladder SMC phenotypes is stable in the culture environments and that SMCs derived from diseased bladders may not be appropriate for tissue engineering purpose without modification of pathologically altered genes expression.

Estimation of bladder volume from afferent neural activity

Refractive urinary dysfunction in individuals suffering from neurogenic bladder syndrome can be treated with implanted neurostimulators that restore, to some degree, the control of the urinary bladder. A sensor capable of relaying feedback from bladder activity to the implanted neurostimulator is required to implement a closed-loop system to improve overall implant efficacy and minimize deleterious effects to neural tissue caused by continuous electrical stimulation. In this paper, we present a method that allows real-time estimation of bladder volume from the primary afferent activity of bladder mechanoreceptors. Our method was validated with data acquired from anesthetized rats in acute experiments. It was possible to qualitatively estimate three states of bladder fullness in 100% of trials when the recorded afferent activity exhibited a Spearman's correlation coefficient of 0.6 or better. Furthermore, we could quantitatively estimate bladder volume, and also its pressure, using timeframes of properly chosen duration. The mean volume estimation error was 5.8 ±3.1%. Our results also demonstrate that it is possible to quantify both phasic and tonic bladder responses during slow filling and isovolumetric measurements, respectively.

Structural and functional characterization of bladder smooth muscle in fetal rats with retinoic acid-induced myelomeningocele

Myelomeningocele (MMC) is the most common cause of neurogenic bladder dysfunction (NBD). We recently developed a novel retinoic acid (RA)-induced MMC model in fetal rats. The objective of this study was to use this model to assess functional and structural characteristics of the detrusor muscle in MMC-associated NBD. Time-dated pregnant Sprague-Dawley rats were gavage fed 60 mg/kg RA dissolved in olive oil or olive oil alone [embryonic day 10 ( E10)]. Bladder specimens from olive oil-exposed fetuses (OIL; n = 71), MMC ( n = 79), and RA-exposed-no MMC (RA, n = 62) were randomly assigned for functional and histopathological evaluation and protein analysis. Contractility responses to field and agonist-mediated stimulation (KCl and bethanecol) were analyzed. The expression patterns of α-smooth muscle actin, myosin, desmin, vimentin, and collagen III and I were analyzed by immunohistochemistry and Western blotting. Spatial and temporal distribution of nerve fibers within the detrusor muscle was monitored by neurotubulin-β-III throughout gestation. Neither OIL, MMC, nor RA detrusor responded to field stimulation. MMC bladder strips showed a significant decrease in contractility after KCl and bethanechol stimulation compared with OIL and RA bladders. Bladder detrusor morphology and expression patterns of smooth muscle markers were similar between groups. Detrusor muscles in OIL and RA fetuses were densely innervated, possessing abundant intramural ganglia and nerve trunks that branch to supply smooth muscle bundles. In MMC bladders, neurotubulin-β-III-positive nerve fibers were markedly decreased with advancing gestational age and were almost completely absent at term ( E22). We conclude that the biomechanical properties of fetal rat MMC bladders are analogous to that seen in humans with MMC-associated NBD. Decreased nerve density indicates loss of peripheral neural innervation throughout gestation. The early observation of decreased innervation and decreased contractility in the absence of morphologic abnormalities in muscle structure or extracellular matrix supports a pathophysiological hypothesis that denervation is the primary insult preceding the observed alterations in bladder muscle structure and function.

Diabetic cystopathy: neuropathological examination of urinary bladder biopsies

Neuropathological examination of bladder biopsies was done on 14 patients with severe insulin-dependent adult-onset diabetes and compared with the acetylcholinesterase and S100 staining of 38 control specimens. A decrease in acetylcholinesterase activity, due to axonal degeneration was found in all cases. An increase in S100 positivity was found in the majority and is due to Schwann cell proliferation as a regeneration attempt after demyelination or axonal degeneration. When acetylcholinesterase activity decreases and an S100 density increase is found in a patient with diabetes, this combination is highly suggestive of thorough diabetic cystopathy amenable to early symptomatic treatment.