Variations in Valsalva leak point pressure with increasing vesical volume

PURPOSE: Although leak point pressure testing is a valuable tool in the diagnosis of female stress urinary incontinence, little standardization in methodology exists. We examined the effect of vesical volume on leak point pressure to assess the need for determining an optimal volume for leak point pressure testing. MATERIALS AND METHODS: Video urodynamic testing was performed in 52 consecutive women with a mean age of 52 years who presented with stress urinary incontinence. By fluoroscopic criteria stress urinary incontinence was type I in 12 patients, type II in 20 and type III in 20. Leak point pressure determined at 50 cc volume increments was correlated with fluoroscopic criteria. RESULTS: Women with type I stress urinary incontinence had high leak point pressure, which remained high at increasing vesical volumes, and those with type III had low leak point pressure, which remained low at increasing volumes. In patients with type II incontinence initially high leak point pressure decreased significantly at increasing vesical volumes. The most appropriate classification of patients occurred at a volume of 250 to 300 cc. CONCLUSIONS: Leak point pressure is affected by vesical volume. At a volume of 250 to 300 cc leak point pressure correlates best with fluoroscopic findings, and it may be used to guide therapy in women presenting with stress urinary incontinence.