What are the urological causes of urinary retention?

From the Guidelines

Urinary retention can be caused by several urological conditions, with benign prostatic hyperplasia (BPH) being the most common cause in men, as an enlarged prostate compresses the urethra, making it difficult to empty the bladder completely 1.

Urological Causes of Urinary Retention

The causes of urinary retention can be categorized into obstructive and non-obstructive causes. Obstructive causes include:

• Benign prostatic hyperplasia (BPH)
• Urethral strictures
• Bladder stones
• Prostate cancer Non-obstructive causes include:
• Neurogenic bladder dysfunction
• Pelvic organ prolapse in women
• Medications such as anticholinergics, alpha-adrenergic agonists, and certain antidepressants

Diagnosis and Evaluation

Diagnosis and evaluation of urinary retention involve a combination of patient history, physical examination, and diagnostic tests such as uroflowmetry, ultrasound post-void residual (PVR) assessment, and urethro-cystoscopy 1.

Management

Management of urinary retention depends on identifying and treating the underlying cause, which may involve:

• Catheterization for immediate relief
• Medications like alpha-blockers for BPH
• Surgical interventions for mechanical obstructions
• Urethral endoscopic management or immediate suprapubic (SP) cystostomy for urgent management of urethral stricture 1 In patients with neurogenic lower urinary tract dysfunction (NLUTD), management involves risk stratification and surveillance, with low-risk patients requiring minimal evaluation and high-risk patients requiring annual clinical assessment, renal function assessment, and upper tract imaging 1.

From the FDA Drug Label

In A Long-Term Efficacy and Safety Study, efficacy was also assessed by evaluating treatment failures Treatment failure was prospectively defined as BPH-related urological events or clinical deterioration, lack of improvement and/or the need for alternative therapy. BPH-related urological events were defined as urological surgical intervention and acute urinary retention requiring catheterization.

The following table (Table 5) summarizes the results. Patients (%)* Event Placebo N=1503 Finasteride N=1513 Relative Risk† 95% CI P Value† Table 5: All Treatment Failures in A Long-Term Efficacy and Safety Study All Treatment Failures 37.1 26.2 0.68 (0.57 to 0.79) <0.001 Surgical Interventions for BPH 10.1 4.6 0.45 (0.32 to 0.63) <0.001 Acute Urinary Retention Requiring Catheterization 6.6 2.8 0. 43 (0.28 to 0.66) < 0.001

The urological causes of urinary retention mentioned in the drug label are:

• BPH-related urological events:
  • Urological surgical intervention
  • Acute urinary retention requiring catheterization
• Clinical deterioration:
  • Lack of improvement
  • Need for alternative therapy
• Surgical Interventions for BPH
• Acute Urinary Retention Requiring Catheterization 2 2

From the Research

Urological Causes of Urinary Retention

The urological causes of urinary retention can be classified into several categories, including:

• Obstructive causes:
  • Benign prostatic hyperplasia (BPH) is the most common cause of urinary retention, accounting for 53% of cases 3
  • Prostatitis, cystitis, urethritis, and vulvovaginitis are other common obstructive causes 4
• Infectious and inflammatory causes:
  • Urinary tract infections (UTIs) can cause urinary retention 4, 5
• Neurologic causes:
  • Cortical, spinal, or peripheral nerve lesions can cause urinary retention 4
  • Neurogenic bladder is a common cause of chronic urinary retention 4, 6
• Pharmacologic causes:
  • Medications with anticholinergic activity, such as antipsychotic drugs and antidepressant agents, can cause urinary retention 7
  • Opioids and anaesthetics can also cause urinary retention 7
  • Alpha-adrenoceptor agonists, benzodiazepines, NSAIDs, detrusor relaxants, and calcium channel antagonists have been associated with urinary retention 7

Specific Causes in Men and Women

In men, the most common cause of urinary retention is BPH 4, 3. In women, the most common cause is weakened power of the detrusor muscle 6. Other causes, such as pelvic organ prolapse, can also contribute to urinary retention in women 5.

Diagnosis and Management

Diagnosis of urinary retention involves a thorough history, physical examination, and selected diagnostic testing, including measurement of postvoid residual (PVR) volume of urine 4, 3. Management of urinary retention depends on the underlying cause and may include bladder catheterization, alpha blockers, and surgical or medical treatments 4, 5, 3.