BENIGN PROSTATIC HYPERPLASIA III: COMPLICATIONS AND MEDICAL TREATMENT
The most important clinical feature of benign prostatic hyperplasia (BPH) is the functional disturbance of urination that results from bladder outlet obstruction. Prostatic enlargement obstructs the urethra and increases the bladder pressure required for normal micturition. This leads to compensatory or work hypertrophy of the bladder wall. With chronic obstruction, the thickened bladder wall develops trabeculations and cellules, and ultimately, diverticulae. After reaching its limit of compensation, the bladder ﬁnally dilates and decompensates and eventually becomes atonic and ﬂaccid, with the loss of contractility. During this process of decompensation, residual urine accumulates after urination and hydrostatic pressure is transmitted through incompetent or obstructed ureteral oriﬁces to the kidneys, resulting in hydroureter and hydronephrosis. Thus, obstructive uropathy due to prostatism is an uncommon but important cause of renal failure. Super- imposed acute pyelonephritis accelerates renal damage and can precipitate fatal uremia, especially when the hydronephrosis has lowered renal reserve. Hydronephrosis can develop insidiously when urinary symptoms are minimal; in such cases, medical attention may be sought because of uremic symptoms, including nausea, vomiting, anorexia, headaches, weakness, and even convulsions. Equally life-threatening is urosepsis that may occur from poor bladder emptying in the setting of infected urine.
The onset and severity of urinary symptoms depend in part on the location of BPH nodules. A strategically situated median lobe may actually cause earlier and more severe obstruction from “ball-valving” into the bladder neck than might extensive lateral-lobe hyperplasia. Early symptoms of BPH are urinary hesitation, a decrease in the caliber of the stream and day and nighttime urinary frequency, reﬂecting disturbances in bladder function. As the bladder wall thickens, the voiding capacity is reduced, resulting in worsening urinary frequency. Urination may be interrupted or may require several efforts for completion, because the bladder wall loses tone and tires quickly. In the end- stage condition, the dilated and acontractile bladder holds large quantities of residual urine that can lead to overﬂow incontinence. In the later stages, acute urinary retention may occur, especially during periods of excess ﬂuid intake and output.
Hematuria is also common with BPH, as it is associated with neovascularity and dilated veins on the urethral surface. Superimposed infection (cystitis) may also aggravate the symptoms, It should be stressed, however, that the symptoms of BPH may be mild and remain stable for years, especially if the bladder is compensating efﬁciently.
Treatment of benign prostatic hyperplasia should begin with an assessment of urinary symptoms and ﬁndings from urologic evaluation. Standardized symptom score evaluation along with a serum creatinine and prostate-speciﬁc antigen (PSA) and urinalysis usually sufﬁces in most cases. Further evaluation can include measuring urinary ﬂow rates in relation to normalized ranges and assessing postvoid residual urine volumes by ultrasound or catheter placement to better examine the integrity of urination. If watchful waiting is not an option because of symptom severity or compromised urination, oral medical therapy with 5-alpha reductase inhibitors that block the production of DHT from testosterone, or alpha-blockers that relax smooth musculature of the bladder neck, prostate, and urethra are very effective in the majority of cases. 5-Alpha reductase inhibitors affect the secretory prostate and slowly shrink the gland by one-third of its original volume over 6 months. Accordingly, serum PSA will also fall by 50% from baseline levels over the same time frame. As such, this treatment is best suited for larger prostates.
Decreased sexual functioning and increased hair growth are side effects in a minority of cases. In addition, 5-alpha reductase inhibitors may reduce the subsequent development of prostate cancer. Alpha-blockers work more rapidly to improve urination but have side effects that include dizziness and retrograde ejaculation. With this therapy, the prostate will continue to grow and may require more medical or surgical therapy over time. If medical therapy fails, then surgical intervention can be considered as outlined in Plates 4-14 through 4-17.