Chronic Urinary Retention

Chronic urinary retention is persistent incomplete bladder emptying with an abnormally high post void residual volume.

Unlike acute retention, the bladder often enlarges gradually and may become painless.

A commonly used practical definition is a post void residual of at least 300 mL persisting for months, although no single residual volume defines every clinically important case.

Causes include:

Outlet obstruction

• BPH

• Urethral stricture

• Prostate cancer

• Bladder neck obstruction

Detrusor underactivity

• Diabetes

• Chronic overdistension

• Neurological disease

• Age related detrusor dysfunction

• Previous pelvic surgery

High pressure versus low pressure retention

High pressure chronic retention

Bladder pressure remains elevated and is transmitted to the upper urinary tracts. Consequences include:

• Hydroureter

• Hydronephrosis

• Renal impairment

This requires prompt decompression.

Low pressure chronic retention

Large residual volume with relatively low bladder pressure.

Often associated with detrusor underactivity.

Renal function may remain preserved.

Symptoms may include:

• Weak stream
• Hesitancy
• Straining
• Prolonged voiding
• Incomplete emptying
• Frequency
• Overflow incontinence
• Nocturnal enuresis in advanced disease

Some patients are asymptomatic despite residual volumes exceeding one litre.

Look for complications:

• Recurrent UTI
• Bladder stones
• Hydronephrosis
• Renal impairment
• Overflow incontinence
• Recurrent retention episodes

Measure:

• Post void residual
• Creatinine and eGFR
• Urinalysis
• Urine culture when indicated
• Uroflowmetry

Ultrasound should assess:

• Bladder volume
• Bladder wall
• Diverticula
• Hydronephrosis
• Upper tract dilatation

Cystoscopy is indicated when:

• Urethral stricture is suspected
• Haematuria exists
• Bladder tumour or stone is possible

Urodynamics is particularly valuable when the distinction between:

• Bladder outlet obstruction

and

• Detrusor underactivity

will determine whether outlet surgery is likely to help.

Urgently decompress when there is:

• Renal impairment

• Hydronephrosis

• Recurrent infection

• Severe symptoms

• Overflow complications

• Very large residual with progressive deterioration

Use:

• Urethral catheter

or

• Suprapubic catheter

Monitor for post obstructive diuresis.

Long term bladder drainage

When definitive correction is not immediately possible:

• Clean intermittent catheterisation is preferable to chronic indwelling catheterisation when the patient or caregiver can perform it reliably.

• An indwelling suprapubic catheter is often preferable to prolonged urethral catheterisation when permanent drainage is necessary.

Outlet obstruction

Treat the cause.

BPH may require:

• Medical treatment

• TURP

• Endoscopic enucleation

• Aquablation

• Simple prostatectomy for very large glands

Urethral stricture requires stricture directed treatment.

Detrusor underactivity

Reducing prostate resistance can still help selected men with mixed obstruction and detrusor weakness, but surgery cannot restore a severely acontractile detrusor.

Patients with persistent acontractile bladder may require long term intermittent catheterisation.

Repeated outlet surgery in a patient whose fundamental problem is absent detrusor contraction should be avoided.