Lower urinary tract symptoms (LUTS) affect approximately 2.3 billion people worldwide, of whom approximately half or men.
It is reported that 13% of men age 40 to 49 years and 28% of men older than 70 years have BPH.
Divided into obstructive and irritative categories.
Obstructive symptoms include straining, hesitancy, weak stream, intermittency, and sense of incomplete bladder emptying.
Irritative symptoms include urgency, frequency and nocturia.
Uroflow study is a objective, noninvasive way to evaluate such symptoms.
Uroflow study requires at least 150 cc of urine volume.
Abnormal results in uroflow is seen in patients with detrusor muscle dysfunction.
Peak urinary flow rates of less than 15 mL/s and increased urine residuals often present in men with BPH.
Risk factors include BPH, overactive bladder, family history, metabolic syndrome, including obesity, dyslipidemia, hypertension, insulin resistance, increased waist to hip ratio,and older age.
In men lower urinary tract symptoms can be caused by bladder outlet obstruction secondary to benign prosthetic hypertrophy, an overactive bladder detrusor, a syndrome of urinary urgency and frequency, or both.
Chronic bladder outlet obstruction can lead to collagen deposition in the bladder wall, caused diffuse bladder wall, thickening, decreases detrusor contractility, and decreased bladder compliance and may cause bladder diverticula.
These processes can further exacerbate obstructive LUTS and will cause irritative symptoms, such as urgency, frequency, and incontinence.
Chronic urinary retention secondary to bladder outlet obstruction or decompensated detrusor can lead to hydronephrosis, kidney insufficiency, bladder calculi, hematuria, and recurrent UTI.
Less common causes of LUTS include prostate or bladder, malignancy, and neurologic disease diseases, such as multiple sclerosis, Parkinson’s disease, stroke, and spinal cord injuries, which may lead to overactive or underactive bladder.
Poorly controlled diabetes may cause urinary frequency secondary to osmotic diuresis or a diabetic neurogenic bladder.
During normal voiding bladder filling is characterized by increased sympathetic detrusor muscle tone and somatic external urethra sphincter tone to maintain continence.
When the bladder is adequately filled, afferent stimulation of sensory nerves in the detrusor alert the brain of the need to void, when appropriate, the brain coordinates voiding by activating the brain stem pontine maturation center to decrease detrusor sympathetic tone, increase the detrusor parasympathetic tone, and decrease somatic sphincter tone.
Abnormalities in the anatomy of physiology of any of these processes can cause LUTS.
Male voiding symptoms caused by bladder or outlet obstruction are due to androgen dependent hyperplasia of both glandular, and stromal prostate elements growing into the lumen of the prostatic urethra, leading to static obstruction.
This hyperplasia is due to lifelong exposure to testosterone that is converted in the prostate to more active dihydrotestosterone by 5- alpha reductase.
Activation of the alpha 1a receptor of prostatic, smooth muscle increases muscle tone around the urethral lumen, crossing dynamic obstruction.
The severity of self-reported LUTS does not necessarily correlate with prostate size of degree of bladder outlet obstruction.
The major contributor to irritative symptoms is thought to be detrusor activity, characterized by uninhibited, involuntary contractions for bladder filling.
Detrusor overactivity is caused by parasympathetic chronic M2/M3 and beta three adrenergic signaling that decreases bladder compliance and causes sensations of urgency and frequency.
Dysfunctional neurologic control of the bladder in efferent parasympathetic signals from the brain to the bladder or sensory afferent pathways from the bladder to the brain may contribute to detrusor over activity.
Inappropriate release of ATP by urothelial cells during bladder filling may also contribute to detrusor over activity.
Diagnosis:
Evaluation includes: a voiding diary, urine analysis, urine culture, bladder ultrasound, PSA level, if there is concern for prostate cancer.
A voiding diary, documents, fluid intake and volumes on a 24 hour level assessing whether LUTS is secondary to diuretic use, excessive fluid intake or caffeine consumption.
Urinalysis can reflect urinary tract infection, or hematuria which needs to be further evaluated.
Physical examination includes palpation of the lower abdomen for bladder distention or bladder scan ultrasound to measure a post void residual volume helps identify urinary retention.
Digital rectal exam is limited value because digital prostate size assessment correlates poorly with actual prostate size.
Treatment:
Behavioral therapy, including pelvic floor physical therapy, timed voiding, and fluid restriction can improve symptoms.
Medications, including alpha blockers (tamulosin)), 5 alpha reductase (finasterase)minhibitors, and phosphodiesterase 5 inhibitors (tadafil), anticholinergics improve lower tract symptoms and can prevent symptom worsening measured by increase IPSS greater than equal to four points or development of secondary sequelae, such as urinary retention.
Combination therapy is more effective than monotherapy.
Treatment for overactive bladder detrusor muscle includes anticholinergics and beta3 agonists (mirabegron) , reduces voiding frequency by 2 to 4 times per day and reduces episodes of urinary incontinence by 10 to 20 times per week.
Surgery such as TURP, holmium laser enucleation and minimally invasive surgery are highly effective for refractory, complicated cases of BPH.
Minimally invasive procedure such as water vapor therapy and prostatic urethral lift have lower complications of incontinence, erectile dysfunction, and retrograde ejaculation, but are associated with increased need for surgical retreatment compared with TURP and holmium laser enucleation of the prostate.
Behavior modifications, eliminating excess fluid intake, caffeine, and alcohol and restricting fluid several hours before sleep are the major components of such therapy, level exercises and pelvic floor physical therapy for urgency and timed voiding and double voting can address incomplete bladder emptying.
Caffeine can exacerbate frequency and irritative symptoms through diuresis and detrusor excitatory affects media via central maturation centers.
Caffeine reduction can improve urinary urgency and nocturnal and enuresis.