Proposal for a urodynamic redefinition of detrusor underactivity

Area of Science:

• Urology
• Urodynamics
• Lower Urinary Tract Symptoms

Background:

• Idiopathic detrusor underactivity (IDU) presents with voiding lower urinary tract symptoms (LUTS) in men.
• A clear urodynamic definition for IDU in non-obstructed, non-neurological men is lacking.
• Understanding IDU is crucial for effective diagnosis and management of voiding dysfunction.

Purpose of the Study:

• To establish a comprehensive urodynamic definition for idiopathic detrusor underactivity in men.
• To differentiate IDU based on detrusor contraction strength and speed.
• To investigate the relationship between urodynamic parameters and bladder emptying efficiency.

Main Methods:

• Retrospective analysis of 75 men with voiding LUTS and 40 age-matched controls.
• Assessment of intrinsic detrusor contraction strength (isovolumetric detrusor pressure) and speed (maximum possible detrusor contraction velocity).
• Determination of bladder emptying efficiency using nonparametric statistics.

Main Results:

• All 75 patients met the criteria for detrusor underactivity, defined by reduced contraction velocity and/or pressure compared to controls.
• Patients were classified into three groups based on detrusor contractility and bladder emptying efficiency.
• Significant decreases in maximum possible detrusor contraction velocity and isovolumetric detrusor pressure were observed in patients compared to controls and across patient groups.

Conclusions:

• Detrusor underactivity in this cohort was primarily characterized by reduced detrusor contraction speed rather than strength.
• A revised definition emphasizing bladder speed and/or strength, with or without poorly sustained contractions, proved more effective.
• The proposed classification may represent the evolutionary stages of IDU, from initial impairment to significant voiding dysfunction.