Rigi10™ Malleable Penile Prosthesis
Also Known As
Post-void residual urine, PVR, residual urine volume (RUV), post-micturition residual, bladder residual volume, incomplete bladder emptying
Definition
Residual urine, also known as post-void residual (PVR) urine volume, refers to the amount of urine that remains in the bladder after a voluntary void or urination has been completed.1 This physiological parameter serves as an important diagnostic tool in urological assessment and can indicate various underlying pathological conditions affecting the urinary system.2 The normal residual urine volume in adults is generally considered to be less than 50-100 mL, with volumes exceeding this threshold potentially indicating abnormal bladder function.3
The presence of significant residual urine occurs when the bladder cannot be completely emptied during micturition, which may result from mechanical obstruction, neurological dysfunction, or muscular impairment affecting the coordinated action between the bladder detrusor muscle and urethral sphincters.4 When the bladder fails to empty completely, the rinsing function of the bladder is impaired, creating an environment where bacteria can more easily colonize the bladder wall, potentially leading to recurrent urinary tract infections and other complications.5
Clinical Context
Residual urine assessment plays a crucial role in the evaluation of various urological and neurological conditions. Clinically, measurement of post-void residual volume is indicated in patients presenting with symptoms of lower urinary tract dysfunction, including urinary frequency, urgency, hesitancy, weak stream, intermittency, and sensations of incomplete bladder emptying.1
The measurement of PVR is particularly important in the assessment of patients with suspected bladder outlet obstruction, such as benign prostatic hyperplasia (BPH) in men, or those with neurogenic bladder dysfunction resulting from conditions like multiple sclerosis, spinal cord injury, or diabetic neuropathy.2 In men with BPH, elevated PVR volumes may indicate the progression of the condition and help guide treatment decisions, although there is a surprising lack of clear correlation between elevated PVR and episodes of acute urinary retention (AUR) in some studies.3
In clinical practice, PVR measurement is typically performed immediately after voiding, as delays of as little as 10 minutes from bladder emptying to PVR determination can cause clinically significant overestimation of the volume.4 The measurement can be obtained using several methods, including transurethral catheterization (considered the gold standard but invasive), portable dedicated bladder ultrasound devices (bladder scanners), or formal bladder ultrasound examination.5
Elevated residual urine volumes may lead to several complications if left untreated, including recurrent urinary tract infections, bladder stones, and in severe cases, hydronephrosis and kidney damage due to backward pressure on the ureters and kidneys.6 Treatment approaches for elevated residual urine volumes depend on the underlying cause and may include pharmacological interventions, surgical procedures to relieve obstruction, or intermittent self-catheterization to manually empty the bladder.7