URETHRAL INSTABILITY AS AN IMPORTANT ELEMENT OF DYSFUNCTIONAL VOIDING

Continuous urethral pressure measurements; measurement techniques; pressure variations; clinical interpretations; and clinical relevance. A Systematic Literature Analysis

AIMS

The clinical relevance of urethral pressure variations (UPV) in the pathophysiology of over active bladder syndrome (OAB) has remained controversial to date. Some studies report an association with OAB and/or detrusor over activity (DO). Recently the International Consultation on Incontinence-Research Society recommended new clinical research to be performed on this subject. We provide a systematic review of the literature to specify this recommendation.

METHODS

Literature search was performed in PubMed, Embase, Web of Science, Cochrane, Central, Cinahl, Academic Science Premier, Science Direct, and Wiley Online using a sensitive search string combination. All authors independently reviewed and scored full text papers and consensus about methodological quality was obtained according to Oxford Level of Evidence (LoE).

RESULTS

Four hundred eighty seven abstracts were screened, 25 papers met all predefined inclusion selection criteria. Incidence figures of UPV varied between 2% and 95%. Studies are of poor methodological quality with Oxford LoE scores of 3B and 4. Measurement methods and techniques show a large variety. The above mentioned association of DO/OAB with UPV is however frequently reported.

CONCLUSION

There exists a phenomenon of UPV, apart from DO, which may be a separate entity within OAB syndrome. Large variation in measurement techniques and patient populations hinders fundamental research as well as clinical progress. Clinical relevance of UPV and consequences for treatment therefore are yet to be established. Future prospective research with well-defined patient population and standardised urodynamic measurement techniques is needed. Results of standardized and objective evaluations should be compared to clinical signs and symptoms by validated questionnaires. Neurourol. Urodynam. 36:51-56, 2017. © 2015 Wiley Periodicals, Inc.

Regional differences in sensory innervation and suburothelial interstitial cells in the bladder neck and urethra

OBJECTIVE

To identify and characterize possible structural specialisations in the wall of the lower urinary tract (LUT) in the region of the bladder urethral junction (BUJ), with the specific objective of identifying regional variations in sensory nerve fibres and interstitial cells (ICs).

MATERIALS AND METHODS

The bladder base and urethra was removed from five male guinea pigs killed by cervical dislocation. Tissue pieces were incubated in Krebs' solution at 36 degrees C, gassed with 95% O(2) and 5% CO(2), fixed in 4% paraformaldehyde and processed for immunohistochemistry. The nonspecific marker vimentin and the general neuronal marker protein gene product (PGP) 9.5 were used to identify ICs and nerve fibres, respectively. Specific antibody binding was visualized using the appropriate secondary antibodies.

RESULTS

The wall of the LUT in the region immediately between the bladder base and the urethra, the BUJ, differed in its cellular composition relative to the adjacent areas. PGP-positive (PGP(+)) nerve fibres, presumptive afferent fibres, lay within the urothelium running between the epithelial cells. There were two general nerve patterns: branching fibres with no varicosities, and complex fibres with varicosities. Fibre collaterals with varicosities exited the urothelium and occupied the space under the urothelium adjacent to the layer of suburothelial ICs. The latter, lamina propria and around the muscle bundles were identified using vimentin (vim(+)). In the base a few vim(+) cells were also PGP(+). In the region of the BUJ there was a decrease in the amount of smooth muscle. In this region, below the lamina propria, there was an area densely populated with vim(+)/PGP(+) ICs. Nerve fibres ran between the cells in this region.

CONCLUSION

These structural specialisations within the urothelium and deeper layers of the BUJ suggest that they might be associated with specific functions. The localized highly branched network of the putative afferent nerves suggests the presence of a local axonal reflexes involving possible cross-talk between the urothelium and suburothelial layer. The function of the specialized region of ICs is not known and must await further information on the functional properties of this novel cell type. These observations show further the cellular heterogeneity of the cells in the LUT and the complexity of the structures. One of the major current challenges in functional urology is to understand the relationships between these novel structures and overall bladder and urethral function.

The standardization of terminology of lower urinary tract function in children and adolescents: report from the Standardisation Committee of the International Children's Continence Society

PURPOSE

We updated the terminology in the field of pediatric lower urinary tract function.

MATERIALS AND METHODS

Discussions were held of the board of the International Children's Continence Society and an extensive reviewing process was done involving all members of the International Children's Continence Society as well as other experts in the field.

RESULTS AND CONCLUSIONS

New definitions and a standardized terminology are provided, taking into account changes in the adult sphere and new research results.

DYSFUNCTIONAL ELIMINATION SYNDROME AS AN ETIOLOGY OF IDIOPATHIC URETHRITIS IN CHILDHOOD

PURPOSE

Idiopathic urethritis (IU) of childhood or urethrorrhagia is a common problem characterized by blood spotting in the underwear between voiding. A clear etiology has not been established and treatments vary. We postulate that idiopathic urethritis is a manifestation of underlying dysfunctional elimination syndrome (DES).

MATERIALS AND METHODS

During a 5-year period we reviewed the records of all children diagnosed with IU in our practice. In total 72 children fit the analysis criteria. There were 68 boys and 4 girls. All children presented with either gross blood per urethra or microhematuria. Children with active infection, immunodeficiency, neurogenic bladder, vesicoureteral reflux, infravesical obstruction, urethral trauma or other genitourinary anomalies were excluded. Evaluation included thorough history and physical examination, urinalysis and urine culture. Renal and bladder ultrasound, voiding cystourethrogram and uroflow/electromyogram/post-void residual volume were obtained in select patients. Study children were divided into 2 cohorts. The first cohort (group 1, 37 patients) was treated with traditional remedies using antibiotics, urinary analgesics and/or anticholinergics. The second cohort (group 2, 35 patients) was treated by bowel and bladder regimens, laxatives when necessary, and biofeedback and/or alpha-blockers when sphincter dyssynergia was identified.

RESULTS

A total of 13 patients in group 1 (35%) had a full response to treatment, 6 (16%) had a partial response and 18 (49%) failed to respond. A total of 29 patients in group 2 (83%) had a full response to treatment, 2 (6%) had a partial response and 4 (11%) had no response. It took an average of 12.1 months to respond fully in group 1, while in group 2 the same full response took an average of 5.2 months. Of the 18 children who crossed over from group 1 to group 2, 15 (83%) had a full response with an average response time of 7.3 months.

CONCLUSIONS

Our data clearly reveal a higher cure rate when children with urethritis are treated according to DES guidelines. IU of childhood is a manifestation of underlying DES and should be treated as such.

alpha1-Adrenergic mechanism in diabetic urethral dysfunction in rats

PURPOSE

We investigated the contribution of alpha1-adrenoceptor mechanisms to urethral dysfunction associated with diabetes mellitus (DM) in rats.

MATERIALS AND METHODS

Eight weeks after streptozotocin injection (65 mg/kg intraperitoneally) the effects of DM on urethral relaxation mechanisms were evaluated with subjects under urethane anesthesia by simultaneous recordings of intravesical pressure in isovolumetric conditions and urethral perfusion pressure (UPP).

RESULTS

In diabetic rats the intravesical pressure thresholds for inducing urethral relaxation and the lowest urethral pressure (UPP nadir) during urethral relaxation were significantly higher by 142% and 86%, respectively, than in normal rats, while baseline UPPs were not significantly different. The mean rate of high frequency oscillations of urethral striated muscle in diabetic rats was also significantly lower by 23% than in normal rats. After alpha-bungarotoxin treatment (333 mug/kg intravenously) to eliminate striated muscle sphincter contractions the SD of baseline UPPs was significantly larger by 93% than in normal rats. Intravenous administration of terazosin (0.4 mg/kg), an alpha1-adrenoceptor antagonist, significantly decreased the UPP nadir, intravesical pressure thresholds inducing urethral relaxation and the SD by 41%, 87% and 138%, respectively, in diabetic rats but not in normal rats. In the 2 groups of animals after alpha-bungarotoxin treatment urethral relaxation during a reflex bladder contraction was inhibited by Nomega-nitro-L-arginine (40 mg/kg intravenously), a nitric oxide synthase inhibitor.

CONCLUSIONS

During reflex bladder contractions streptozotocin induced diabetic rats showed smooth and striated muscle dysfunctions of the urethra. The inhibition of alpha1-adrenoceptors, which decreased the UPP nadir and UPP fluctuation, may be useful for treating urethral dysfunction in DM.

Bladder and urethral responses to pelvic nerve stimulation in the pig

OBJECTIVE

The aim of our study of the pig was to investigate the responses of smooth muscle of the bladder and the urethral sphincter to preganglionic parasympathetic stimulation, and to assess the effect on the lower urinary tract of IV administration of alpha,beta-methylene-ATP.

MATERIALS AND METHODS

In seven anaesthetised female pigs, the responses to repeated 20 s pelvic nerve stimulations before and after IV administration of 0.02 mg/kg alpha-beta-methylene-ATP, and the responses to the drug itself, were recorded in the bladder and the urethra separately.

RESULTS

In the urethral high-pressure zone, pre-stimulation pressure was a mean of 61+/-11 cmH2O. During pelvic nerve stimulation, urethral pressure declined by 48+/-9 cmH2O, while the bladder pressure increased to 30+/-18 cmH2O. The rate of pressure changes during the first 3 s of stimulation (initiation of voiding) was larger in the urethra than in the bladder (urethral pressure decrease: 13.0+/-3.1 cmH2O/s, bladder pressure increase: 3.2+/-2.5 cmH2O/s). Administration of alpha,beta-methylene-ATP was followed by a significant but temporary enlargement in the bladder response to pelvic nerve stimulation to 36+/-20 cmH2O, p = 0.028, n = 7, but no change in urethral response.

CONCLUSIONS

At least 80% of the urethral pre-stimulation pressure was exerted by the smooth muscle. The synergic activation of the detrusor and the urethral smooth muscle in response to preganglionic parasympathetic nerve stimulation was controlled by the peripheral nerves or by the neuromuscular transmission. Administration of alpha,beta-methylene-ATP increased the bladder response to pelvic nerve stimulation without changing the urethral response.

Neurogenic and non-neurogenic bladder dysfunction

Children with a neurological defect have a clear cause for their bladder dysfunction; however, in neurologically normal children the cause of their incontinence is usually unclear. When no anatomical abnormalities seem to be present a functional problem is generally the cause. This type of incontinence is referred to as 'functional incontinence'. The different forms of bladder and sphincter dysfunction will be discussed and treatment modalities described. As the treatment modalities in children with neuropathic bladders focus on medical and especially surgical options, special attention is paid to new developments in surgical treatment. For those with functional incontinence treatment options are more variable and the new developments are described.

Neurogenic failures of the external urethral sphincter closure and relaxation; a videourodynamic study

Urinary urgency and voiding difficulty are common features in neurological diseases, which can be attributed to dysfunction of the urethral sphincter and the detrusor. However, little is known about dynamic sphincter behaviour in neurological diseases. The present study aimed at investigating neurogenic failures of the external urethral sphincter closure and relaxation by videourodynamic study. We recruited 44 neurological patients with urinary urgency and frequency, 27 men and 17 women, mean age 61 years, and 28 of them had voiding difficulty as well. None had abnormal finding of digital examination or ultrasound echography of the pelvic organs. Using triple-lumen 7F catheter under X-ray fluoroscope, we measured detrusor pressure, external urethral sphincter pressure (Pura) and external sphincter EMG in all patients. We also performed pressure-flow study and obtained the Abram-Griffiths (AG) number, a numerical grade of obstruction. During filling 30 had detrusor hyperreflexia. EMG-cystometry showed uninhibited external sphincter relaxation (UESR) in eight patients, seven of whom had detrusor hyperreflexia as well. Patients with UESR showed an abnormal reduction of Pura, mean reduction 64 +/- 27 cmH2O (mean +/- standard deviation). During UESR the Pura and EMG activity fluctuated, and fluoroscopic image showed bladder neck opening in four with extreme urge sensation, including one without detrusor hyperreflexia. During an attempt of voiding three patients with voiding difficulty had detrusor-external sphincter dyssynergia (DESD) with detrusor contraction and eight had unrelaxing external sphincter without detrusor contraction. Fluoroscopic image showed an incomplete or absent urethral opening at the external sphincter. Four of them had severe straining on voiding together with intermittent increment of EMG activity without a normal funneling of the bladder neck. The mean reduction of Pura during voiding was 6.4 +/- 6.7 cmH2O and 5.0 +/- 9.5 cmH2O (in women and men, respectively) with DESD or unrelaxing external sphincter which was less than 39 +/- 25 cmH2O and 53 +/- 47 cmH2O in those without (P < 0.01). The mean AG number was 15 +/- 21 and 51 +/- 19 (for women and men, respectively) with DESD or unrelaxing external sphincter which was larger than 6.2 +/- 34 and 35 +/- 22 in those without (P < 0.05). In conclusion, UESR and DESD/unrelaxing external sphincter could be a factor for urinary urgency and voiding difficulty in neurological patients, evidence of central dysregulation affecting the Onuf's nucleus and its fibres to the external urethral sphincter.

Neuronal innervation of urethral and anal sphincters: surgical anatomy and clinical implications

The present review describes the neuronal innervation of the external urethral and anal sphincters. A knowledge of this innervation helps in understanding the clinical symptoms of urinary and anorectal pathology, and in choosing the appropriate technique of nerve localization or block. An ability to locate the pudendal nerve, on the basis of surgically documented anatomy, has important diagnostic and therapeutic advantages. It can be used to study the integrity of pelvic floor muscles, in biofeedback training, nerve blocks, pudendal canal decompression, chronic stimulation trials to treat urinary or faecal incontinence, and in nerve conduction studies or evoked potential recordings. Furthermore, the superficial location of the sphincteric innervation in the perineum and ischiorectal fossa renders the nerve branches susceptible to injury during operative correction of urinary or faecal incontinence. Supported by a knowledge of anatomy, we can make firm recommendations on which to base safe surgical techniques that avoid damage to urethral and anal sphincteric innervation.

Paediatric voiding dysfunction and enuresis

Urinary incontinence and nocturnal enuresis are frequently encountered problems in children. In this review some aspects will be highlighted. Especially the different types of monosymptomatic nocturnal enuresis as well as some recent developments in children with dysfunctional voiding will be discussed.

Non-bacterial cystitis

The concept of non-bacterial cystitis (NBC) combines sterile urine and cystitic symptoms as well as inflammatory changes, in particular in the mucosa and submucosa of the bladder. It includes a multiplicity of vicious circles along the entire continence reflex. An understanding of NBC presupposes knowledge of the origin of the normal urinary urge and its successful control. Against the background of the steadily increasing incidence of interstitial cystitis (often irreversible end-stage NBC), it is suggested here that in the face of a failure of first-line therapeutics (anticholinergics, cyclic antidepressants or oestrogens), one must consider without delay the possible presence of NBC.