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.
