Chapter 81: Benign Prostatic Hyperplasia

INTRODUCTION

• Benign prostatic hyperplasia (BPH), is a non-cancerous condition in which an enlarged prostate compresses the urethra, blocking the outflow of urine. It is characterized by three stages: BPH, benign prostatic enlargement (BPE), and benign prostatic obstruction (BPO).

PATHOPHYSIOLOGY

• Three types of prostate gland tissue are epithelial or glandular, stromal or smooth muscle, and capsule. Both stromal tissue and capsule are embedded with α₁-adrenergic receptors.

• The precise pathophysiologic mechanisms that cause BPH are not clear. Both intraprostatic dihydrotestosterone (DHT) and type II 5α-reductase are believed to be involved.

• BPH commonly results from both static (gradual enlargement of the prostate) and dynamic (agents or situations that increase α-adrenergic tone and constrict the gland’s smooth muscle) factors. Examples of drugs that can exacerbate symptoms include testosterone, α-adrenergic agonists (eg, decongestants), and those with significant anticholinergic effects (eg, antihistamines, phenothiazines, tricyclic antidepressants, antispasmodics, and antiparkinsonian agents).

CLINICAL PRESENTATION

• Patients present with a variety of signs and symptoms categorized as obstructive or irritative. Symptoms vary over time.

• Obstructive signs and symptoms result when dynamic and/or static factors reduce bladder emptying. Patients experience urinary hesitancy, urine dribbles out of the penis, and the bladder feels full even after voiding.

• Irritative signs and symptoms are common and result from long-standing obstruction at the bladder neck. Patients experience urinary frequency, urgency, and nocturia.

• Obstructive and irritative voiding symptoms are referred to as lower urinary tract symptoms (LUTS) which are not limited to BPH but may also be caused by neurogenic bladder or urinary tract infections.

• BPH progression may produce complications including urinary retention, chronic kidney disease, gross hematuria, urinary incontinence, recurrent urinary tract infection, bladder diverticula, and bladder stones.

DIAGNOSIS

• Includes careful medical history, physical examination, objective measures of bladder emptying (eg, peak and average urinary flow rate and postvoid residual [PVR] urine volume), and laboratory tests (eg, urinalysis and prostate-specific antigen [PSA]).

• On digital rectal examination, the prostate is usually but not always enlarged (>20 g), soft, smooth, and symmetric.

TREATMENT

• Goals of Treatment: The goals are to control symptoms, prevent progression of complications, and delay need for surgical intervention.

• Management options include watchful waiting, pharmacologic therapy, and surgical intervention. The choice depends on severity of signs and symptoms (Table 81-1).

• Watchful waiting is appropriate for patients with mild disease (Fig. 81-1). Patients are reassessed at 6–12 month intervals and educated about behavior modification, such as fluid restriction before bedtime, minimizing caffeine and alcohol intake, frequent emptying of the bladder, and avoiding drugs that exacerbate voiding symptoms.