Objective: The aim of our study was to find correlation between Valsalva leak-point pressure (VLPP) and cough leak-point pressure (CLPP) and to determine whether water perfusion maximum urethral closure pressure (MUCP) correlates with Valsalva leak-point pressure (VLPP).
Design: Cross-sectional clinical study.
Settings: Gynecological and Obstetric Clinic, 1st Medical Faculty, Charles University and General Faculty Hospital, Prague.
Material and methods: Thirty women with previously untreated GSI were recruited to participate in a clinical study. Their mean age was 56.9, mean body mass index (BMI) 27.6, and mean parity 1.8. As part of the urethral pressure profile we determined MUCP and functional length (FUL) of the urethra. VLPP and CLPP were assessed during US examination using an ultrasound contrast medium and the color Doppler velocity (CDV). Funneling was described as the increase in distance between the inner edges of proximal urethra during Valsalva maneuver.
Results: We did not find statistically significant differences in the mean value of VLPP and CLPP. The mean value of VLPP was 51.6 cm H2O (SD=26.5) and CLPP 53.1 cm H2O (SD=25.5). The mean values of MUCP were 39.7 cm H2O (SD=22.1) with 500 ml and 41.5 cm H2O (SD=22.7) with 300 ml of sterile saline; the difference between them is not statistically significant. In the study group (n=30), 22 patients had low VLPP (< or = 60 cm H2O). Only 8 patients had simultaneously MUCP < or = 30 cm H2O and of these patients only 2 had simultaneously MUCP < or = 20 cm H2O (the bladder volume 300 ml). Similar results were obtained with the bladder volume 500 ml. We did not find statistically significant differences in the funneling of proximal urethra between the groups of patients with low MUCP (< or = 30 cm H2O) and with higher MUCP (> 30 cm H2O) and between the groups of patients with low VLPP (< or = 60 cm H2O) and with higher VLPP (> 60 cm H2O).
Conclusions: This study mainly compares two parameters--the MUCP and the VLPP. Based on our results we support the theory that ISD has a multifactorial basis, and a low MUCP or a low VLPP derives from two different pathogenic mechanisms. We support the Pajoncini hypothesis that low VLPP correlates with a deficiency in mucosal sealing and compromise of the intrinsic proximal component at the level of the bladder neck, and low MUCP correlates with a deficiency at the level of the rhabdosphincter in the middle urethra. In the future we must establish the prognostic value of the VLPP and the MUCP in the postoperative follow-up.