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University of Oklahoma Health Sciences Center Oklahoma City, Oklahoma
Benign prostatic hyperplasia (BPH) is a histologic as well as a clinical diagnosis. The incidence of histologic BPH is actually higher than that of the clinical form. According to the Bureau of Statistics there are 30 million men in the United States older than 50 years of age. Approximately 30% of these men suffer from symptoms related to BPH,
A process of education regarding BPH is ongoing through industry advertisements and medical lay publications, which encourage visits to the primary care physicians who subsequently identify affected men. Also, the percentage of men older than 50 years of age is expected to increase from 30 to 39% by the year 2000 as ""baby boomers"" age and survival statistics improve. These numbers speak to the socioeconomic implications of BPH in the United States. Recognition of these issues by pharmaceutical and technology companies has resulted in the development of several new medical and surgical treatments.
The clinical presentation of BPH is quite variable. Most commonly the patient will complain of a series of obstructive and irritative symptoms. Obstructive symptoms include decreased urinary flow rate, hesitancy, an intermittent voided stream, the need to strain to urinate, and the sensation of incomplete emptying. Irritative symptoms of BPH include urgency, frequency, nocturia, and dysuria. These symptoms vary in intensity, and they cause a significant reduction in quality of life. Other presentations include signs or symptoms of bladder stones, hematuria, recurrent urinary tract infections (UTIs), overflow incontinence, and complete urinary retention. Although the man who presents to the emergency department with symptoms of heart failure, profound azotemia, hydronephrosis, and a postvoid residual urine of greater than a liter is much less common today, these presentations still do occur. Just as the presentation is variable, the natural history of BPH is likewise variable and often unpredictable: about a third will remain the same, another third will improve, and a third will worsen.
To evaluate BPH initially and follow the clinical course of the disease, a self-administered questionnaire has been developed by the American Urological Association (AUA), presented in Table 2 . This questionnaire elicits information on the presence of obstructive and irritative symptoms (i.e., urgency, frequency, weak stream, intermittent stream, incomplete emptying, hesitancy, and nocturia), which are graded in severity from 1 to 5. These scores are added to yield a composite symptom score of 0 to 35. Scores for mild symptoms are 0 to 8; moderate, 9 to 19; and severe, 20 to 35. Although treatment decisions cannot be made solely on the basis of the AUA symptom score, it is a reliable method for detecting BPH, selecting treatments, and monitoring disease and treatment progression.
Physical examination centers on the genitourinary system.
Abdominal examination may reveal a distended bladder
There are very few useful diagnostic tests and studies in the evaluation of BPH. A urinalysis (UA) should be performed to detect microscopic hematuria and to rule out a UTI, which can mimic or be caused by BOO. A urine culture should be performed if results of UA are suggestive of UTI. A prostate-specific antigen (PSA) level should be determined in all patients over the age of 40 years as a screening test for prostate cancer. Patients suspected of having associated prostatitis or UTI should receive appropriate antibiotic therapy before determination of PSA level. BPH can cause mild to moderate PSA elevations, especially when retention or significant obstruction is present, but even in these cases, serial measurements should be obtained because of the risk of coexistent prostate cancer. Serum creatinine determination is a good screening test to assess renal function. A complete blood count is necessary only in the face of a suspected severe infection or significant bleeding. Measurement of serum electrolytes is necessary only if a high serum creatinine level or heavy proteinuria suggests renal dysfunction.
Urologists commonly perform a uroflow test on patients with BPH since it is readily available to them and very inexpensive. The urinary flow rate and the duration of voiding are useful objective measurements that can be repeated for ongoing evaluation during medical or after surgical therapy. The voiding pattern also gives the urologist clues regarding possible bladder dysfunction that may be mimicking or complicating the BOO. Full urodynamic evaluation is not necessary in the vast majority of patients with BOO due to BPH. Patients in whom history, findings on physical examination, or results of uroflow studies are suspicious for bladder dysfunction (rather than obstruction) should, however, usually undergo urodynamic studies before surgical procedures are considered.
Many conditions can mimic prostatism or BOO (Table 3) . Prostate cancer can cause obstruction of the prostatic urethra. Anatomic obstruction can occur at locations other than the prostate, i.e., with meatal stenosis, urethral stricture
The most serious complications of BPH include recurrent gross hematuria, renal failure, hydronephrosis, recurrent infection, urosepsis, bladder stone formation from stasis of urine, and destruction of the contractile properties of the detrusor muscle from the muscular damage of chronic distention (Table 4) . Less serious complications are reduction in the quality of life from the inconveniences of urinary incontinence, nocturia, recurrent cystitis, and prolonged micturition. Also, chronic fatigue associated with frequent awakening due to nocturia can be quite debilitating.
There are basically three categories of treatment: watchful
waiting, medical treatment, and surgical treatment. Selection of the treatment
modality is based largely on the severity of symptoms, changes
Surgical treatments include transabdominal, transperineal, and transurethral approaches (Table 5) . All of the surgical approaches involve removing (""enucleating"") most or all of the adenoma that affects the transitional (periurethral) and central (near the posterior bladder neck) zones of the prostate; the peripheral zone of prostate tissue remains. The ""open"" surgical procedures are reserved for glands that are so large that troublesome intraoperative complications such as bleeding and electrolyte abnormalities are likely with a transurethral approach. Open prostatectomy effectively reduces the urethral resistance but also destroys part of the patient s continence mechanism, i.e., the bladder neck musculature, and the smooth muscle contractile force of the internal sphincter. Maintenance of continence requires the integrity of the pudendal nerve and the external sphincter. The side effects and risks of surgery include incisional pain and need for blood transfusion in up to 35% of patients. In terms of both short-term and long-term relief of voiding symptoms, open prostatectomy is the most successful of any form of treatment, with 98% of patients having subjective and objective (based on urodynamic studies) improvement. Subsequent reoperation is required in less than 1% of cases per year.
The other forms of surgical therapy involve transurethral delivery
of energy to the prostatic urethra to ablate prostatic adenoma. Transurethral
resection of the prostate (TURP) is the procedure most commonly performed for
BPH. In the standard TURP, a wire loop electrode operated through a large
cystoscopic sheath is used to resect the adenomatous tissue from the inside out
under direct cystoscopic visualization. TURP requires a great deal of training
and skill to perform effectively and safely. The procedure can be performed
with the patient under general
Another transurethral approach is electrovaporization of the prostate using a ""roller ball""-type electrode and very high levels of electric current. Transurethral incision of the prostate involves use of an electric cutting knife to incise the prostate and bladder neck in one or two places. Both electrovaporization and incision are associated with lower rates of bleeding but have been found to be useful primarily only in patients with smaller glands. Laser procedures can be effective but are associated with high morbidity, because the treated tissue has to slough off over the month or so following the procedure. Prostate stents are effective in promoting bladder emptying, but a high incidence of severe irritative voiding symptoms has limited the use of these devices for now. Microwave therapy, cryotherapy, thermal therapy, newer laser techniques, and various other procedures have been or are being proposed, tested, and marketed. None of these techniques has been proved to match the effectiveness of TURP.
Medical treatment of BPH includes the use of alpha blockers and the 5alpha-reductase inhibitor finasteride (Proscar). The alpha blockers include terazosin (Hytrin), doxazosin (Cardura), and the ""prostate-selective"" alpha blocker tamsulosin (Flomax). The less selective alpha blockers have crossover effects on other receptors that can affect the venous and arterial receptors; therefore, these agents can produce systemic side effects such as orthostatic hypotension, syncope, dizziness, somnolence, nasal congestion, and nausea.
The alpha blockers cause relaxation of the smooth muscles at the bladder neck and the prostatic urethra, which can effectively reduce urethral resistance and ameliorate symptoms. The less selective alpha blockers doxazosin and terazosin are administered in slowly escalating doses over a 4- to 5-week period up to 4 and 5 mg, respectively. At these doses, 70% of the patients can be expected to have a 30% improvement in the AUA symptom score. This form of therapy is ineffective in the remaining 30%. Another dose escalation--to 8 mg for doxazosin and 10 mg for terazosin--may provide further symptomatic improvement in some patients. Above these levels, toxicity outweighs benefits. Tamsulosin is a prostate-selective alpha blocker that does not require dose titration. Postural and orthostatic hypotension are
Finasteride produces its effect by blocking the conversion of testosterone to dihydrotestosterone, the most potent androgen. Early studies showed that 50% of patients could expect a 50% rate of symptomatic improvement. A Veterans Affairs cooperative clinical trial, however, has questioned the efficacy of finasteride. Perhaps the best candidate for this agent is a patient with BOO symptoms and a very large prostate.
It should be emphasized that watchful waiting is not an absence of treatment but constitutes a treatment plan in itself. Watchful waiting for BPH involves yearly digital rectal examination (DRE), measurement of prostate-specific antigen (PSA), urinalysis, and monitoring of AUA scores. Complications are treated as they arise, and treatment (surgical or medical) is initiated as needed for symptom progression. Up to 30% of patients managed with watchful waiting experience symptomatic improvement. The patients who get better with watchful waiting, however, tend to be those with mild symptoms of a relatively recent onset, so patient selection for this treatment option is important.
Benign prostatic hyperplasia and its accompanying bladder outlet symptoms are significant causes of morbidity in the older male patient population. A variety of medical and surgical therapies of proven safety and effectiveness are available for treatment of this condition. The challenge facing clinicians today is in properly applying the sometimes bewildering array of treatment methods to their individual patients.
These choices can be guided by some basic principles. First, the severity of a patient s symptoms needs to be determined with some precision, especially the extent to which these symptoms interfere with daily activities and bother the patient. Second, the patient s expectations and hopes regarding treatment must also be identified. Third, the benefits, risks, and cost of each therapy need to be considered and discussed with the patient. Patients with minimal or moderate symptoms, for example, may be very happy with only modest improvement. Patients with severe symptoms, on the other hand, may not be satisfied by merely advancing to a less severe or moderate symptom category.
As previously described, 30% of patients will show some improvement with watchful waiting, but this is usually minimal improvement. With medical therapy, 50 to 70% of patients can be expected to show a 30% improvement in symptoms. With standard transurethral resection of the prostate, about 90% of patients can expect to experience minimal or no BPH symptoms after the initial recovery period.
In summary, then, patients with minimal symptoms are usually best served by watchful waiting or medical therapy. Patients with moderate symptoms are best initially managed with medical therapy, but clinicians must promote realistic expectations by articulating the high expense of the medications, the very real possibility of troublesome side effects, the degree of potential symptomatic improvement, and the 30% possibility of achieving little or no relief at all. Patients with severe symptoms usually need surgical therapy at some point in their clinical course if they hope to achieve significant relief. Here, too, realistic expectations need to be conveyed regarding the possibilities of surgical complications and inadequate symptomatic improvement.
Although therapeutic trials have helped clarify the proper use of these treatments, clinical experience applied attentively to the patient s specific symptoms, expectations, and overall health status remains the cornerstone of care in BPH.
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