Urinary bladder This hollow muscular organ has two main functions: Low pressure (storage) of urine Expulsion of urine at appropriate time (voiding) functional features  normal capacity of 400–500 ml,  sensation of fullness  ability to accommodate various volumes without a change in intraluminal pressure (compliance)  ability to initiate and sustain a contraction until the bladder is empty.  voluntary initiation or inhibition of voiding despite the involuntary nature of the organ.

The urethra and sphincteric mechanism Functions: To provide effective continence mechanism for majority of the time during the storage phase. To allow adequate emptying from the bladder with minimum resistance during the voiding phase. there are 2 sphincteric elements:  an internal involuntary smooth-muscle sphincter at the bladder neck, consists of a powerful inner layer of muscle bundles arranged in a circular orientation.(also prevents retrograde ejaculation).  an external voluntary striated-muscle sphincter from the level of verumentanum down to the distal aspect of membranous urethra in males and at the mid urethra in females.

male and female sphincteric mechanisms

Comparison of male and female sphincteric mechanism MaleFemale Proximal bladder neck mechanism powerfulweak Distal urethral mechanismpowerfulProne to effect of exogenous influences such as pelvic floor weakness and damage or denervation consequent upon childbirth ProstateFurther increases bladder outlet resistance Not present UrethraLong (20-25 cm)Short (3-5 cm)

Pelvic floor muscles Composed mainly of levator ani muscles, endo-pelvic fascia, ad supporting ligaments. Maintain pelvic organs in the correct position and plays a vital role in continence. Form a supporting hammock beneath the urethra, and during increases in intra- abdominal pressure, the urethra is compressed against this hammock.

Ureterovesical junction The function of the ureterovesical junction is to prevent backflow of urine from the bladder to the upper urinary tract. Longitudinal muscle from the ureter contributes to the makeup of the trigone. Stretching of the trigone has an occlusive effect on the ureteral openings.

Neuronal control of the lower urinary tract Coordinates the activities of bladder and sphincteric mechanisms Control receptive relaxation of the bladder (compliance) Sense bladder fullness Maintain continence with increasing bladder fullness Initiate voluntary voiding

Motor (efferent) control The storage phase in under sympathetic control The voiding phase is under parasympathetic control Sensory (afferent ) control Transmit information regarding the fullness of the bladder as well as the presence of any noxious stimuli ( cold or chemical), they are involved in both involuntary reflexes and conscious sensation of bladder fullness.

The principal innervation of the lower urinary tract TypeOriginDetrusor muscle Sphincteric muscle Principal neurotransmitter hypogastricsympatheticT10-L2RelaxationContracts sphincteric smooth muscle Noradrenaline pelvicPara- sympathetic S2-S4 (spinal micturition center) ContractionRelaxationAcetylcholine pudendalSomaticS2-S4 (Onuf’s nucleus) N/AContracts sphincteric striated muscle and pelvic floor Acetylcholine

The micturition reflex Intact reflex pathways via the spinal cord and the pons are required for normal micturition. Afferents from the bladder are essential for the activation of the sacral center, which then causes detrusor contraction, bladder neck opening, and sphincteric relaxation. The pontine center, through its connection with the sacral center, may send either excitatory or inhibitory impulses to regulate the micturition reflex.

Cerebral (suprapontine) control Although micturition and urine storage are primarily functions of the autonomic nervous system, these are under voluntary control from suprapontine cerebral centers, so that other groups of muscles (arm, leg, hand, bulbocavernosus) can be integrated to assist in urination at the appropriate time and place. Cerebral lesions (eg, from tumor,Parkinson’s disease, vascular accident) are known to affect the perception of bladder sensation and result in voiding dysfunction.

Urodynamic studies techniques used to obtain graphic recordings of activity in the urinary bladder, Urethral sphincter, and pelvic musculature. uroflowmetry: is the study of the flow of urine from the urethra

FLOW RATE IS THE PRODUCT OF DETROSAL ACTION AGAINST OUTLET RESISTANCE, so variation from normal might reflect dysfunction. The normal peak flow rate (Qmax) for males is 20–25 mL/s and for females 20–30 mL/s. A flow rate less than 10 ml / sec is definitive evidence of obstruction. THE NORMAL UROGRAPH IS BELL SHAPED average flow, max flow, and flow time.

Cystometry Cystometry simply is a plot of intravesical volume vs. pressure Compliance= volume/pressure Intravesical pressure is the summation of both detrusor pressure and intra-abdominal Pressure Normal voiding pressure are below 40 cm H2O

Sphincteric function Urinary sphincteric function can be evaluated either by recording the electromyographic activity of the voluntary component of the sphincteric mechanism or by recording the activity of both smooth and voluntary components by measuring the intraurethral pressure of the sphincteric unit. The latter method is called pressure profile measurement (profilometry).  Closure pressure: urethral pressure – intravesical pressure i.e the net closure pressure  Functional length: the length of the segment with positive closure pressure

Neuropathic bladder disorder Upper motor neuron lesions or spastic bladder Due to lesions above sacral micturition center, above the conus medullaris T12 vertebral level Due to less of inhibition from higher centers Common lesions include vascular accidents, tumors, multiple sclerosis, and inflammatory conditions like encephalitis. Contracted detrusor results in one of the followings :  Frequency and urgency when the sphincteric pressure is normal  Retention when the sphincteric pressure is high  Incontinence when the sphincteric pressure is low

Lower motor neuron lesions flaccid or atonic bladder Direct damage to peripheral innervation of the bladder or sacral cord segments S2-4 Causes include trauma, tumors,tabes dorsalis, and congenital anomalies (spinal bifida and meningomyelocele) Patients experience principally retention and overflow incontinence, male patients lose their erections.

Patient evaluation should include:  Full neurological examination to establish the sensory level, the anal, bulbocavernosal, knee, ankle, and toe reflexes.  Urine analysis, renal function tests.  Periodic cystourethrograms looking specifically for VUR.  Cystoscopy to evaluate the bladder and urethra  Urodynamic studies to record bladder and sphincteric pressure profiles.

Differential diagnosis Cystitis Chronic urethritis Vesical irritation secondary to psychic disorders Myogenic damage Interstitial cystitis Cystocele Infravesical obstruction

Treatment We need to restore the low pressure activity to the bladder to  protects upper tracts and preserve renal function  Restore continence  Control infection

In spinal shock Intermittent sterile catheterization When indwelling catheterization is needed consider small size foley catheter (16Fr) or SPC VCUG to rule out reflux Cystogram is needed 3 monthly at first then annually looking for complications Encourage plenty of fluid intake, early wheelchair ambulation, and measure to avoid calculus formation.

Spastic bladder: reasonable bladder capacity: trigger techniques to initiate voiding, plus anticholinergic medications. Markedly diminshed capacity:  Indwelling catheter or condom (no VUR)  Parasympatholytic drugs like oxybutanin and delterodine.  Intravesical botulinum toxin injection  Neurostimulation or bladder pacemaker  Bladder augmentation and urinary diversion

Flaccid bladder:  Bladder training: timed voiding every 2 hours, by suprapubic pressure (Crede maneuver) and abdominal wall straining.  Clean intermittent catheterization every 3-4 hours.  Surgery in the form of bladder neck incision or excision or big prostate to reduce bladder outflow resistance.  Parasympathomimetic drugs: bethanicol bromide 50 mg every 6-8 hours.

Urinary incontinence the involuntary loss of urine to the degree that is socially and hygienically unacceptable to the patient.  It affects about 30% of women above 65yrs.  Some elderly patients accept it as a sign of aging  Some times its transient and resolves spontaneously as that which follows child birth or associated with bladder infection  But it is usually chronic and progressive and requires treatment

Types: Anatomic or genuine urinary stress incontinence Urge incontinence Neuropathic incontinence Congenital incontinence False (overflow) incontinence Iatrogenic incontinence Fistulous incontinence

Stress urinary incontinence Is leakage resulting from any type of straining (coughing, laughing, sneezing, or lifting), that puts pressure on the bladder. Common causes are aging, lack of estrogen, neurological disorders and obstetrical / surgical trauma Defect is demonstrable radiologicaly Restoration of normal anatomy restores continence

Mechanism of leak 1. Insufficient urethral support from the endopelvic fascia and muscles is the most important etiology.this results in hypermobility of the vesicourethral segment, here the sphincter itself is intact. 2. Intrinsic Sphincter Deficiency ( ISD ) occurs when there is failure of the urethral sphincter due to mucosal and muscular atrophy and denervation.

Anatomy: The anatomic feature is that of hypermobility or a lowering of the position of the VU segment Various relations between the urethra, bladder, and bony landmarks have been studied  Posterior vesicourethral angle  Axis of inclination (urethral line vs. vesical plane)  UV junction and the SCIPP

Urethral hypermobility test

Radiology Do lateral cystogram with urethral catheter inserted at rest and stress to study the relationship of VU junction and pubic bone, normal mobility during stress should be less than 1.5 cm

Urodynamic Features Low urethral pressure profile, with reduced closure pressure Shorter functional length with the loss in the proximal segment In severe cases there is loss of voluntary increase in urethral pressure These changes may be mild in rest, but will be very prominent during stress

Diagnosis History: Degree of leakage, its relation to activity, position and status of bladder filling Time of onset, and course of progression Previous surgical and obstetrical history Medications taken and medical illnesses Examination: Pelvic exam: laxity of pelvic support, and degree of prolapse Neurological exam should be done if neuropathy is suspected

Cystography is done to demonstrate the anatomic abnormality, not to make the diagnosis The diagnosis is made by urodynamic study in rest and stress

Treatment Conservative therapy may involve hormonal replacement, pelvic floor exercises, bladder retraining, and life style modification such as weight reduction or avoidance of foods that irritate the bladder. Other options include the use of a urethral plug or vaginal pessary. Surgical intervention may be needed to restore anatomical relationships.

Types of Surgical Procedures 1. Retropubic suspensions as,MMK,Burch 2. Transvaginal needle suspension as TVT and TOT. 3. Sling operations as anterior rectus sheath slings 4. Periurethral injection specially for Intrinsic sphincter deficiency

Urge Incontinence The basic feature is detrusor instability and loss of urine while attempting to inhibit micturition The bladder is described to be overactive with clinical symptoms of urgency, frequency, and nocturia The bladder overactivity can result from bladder inflammation, obstruction or neurological trauma

Urodynamic Features Normal or high closure pressure Normal response to stress and filling Detrusor hyperirritability with contractions overcoming urethral resistance In some cases the detrusor pressure remains normal, but there is dropping in the urethral closure pressure leading to leak (urethral instability) Combination of the two

Treatment Bladder training Decreased fluid intake Scheduled voiding Relaxation technique Anticholinergic drugs Intravesical botulinum toxin injection Surgery rarely needed as SNS, augmentation, and diversion