The relationships of urethral and pelvic floor muscles and the urethral pressure measurements in women with stress urinary incontinence

Objectives: To investigate the relationships between urethral and paraureth ral anatomy and urethral pressure measurements in women with stress urinary incontinence (SUI). Materials and Methods: A total of 83 women with SUI and 33 with frequency u rgency syndrome but not SUI were included in the study. The parameters of t ransrectal sonography of the urethra and urethral pressure profilometry wer e compared among the subjects with each of four types of SUI and non-SUI su bjects. Results: Videourodynamic study revealed that 26 women had type 0 SUI, 39 ha d type 1 SUI, 19 had type 2 SUI and 9 had type 3 SUI. The urethral striated muscular area was significantly smaller in subjects with type 3 SUI than i n subjects with type 0 SUI and in non-SUI subjects. The thickness of the ur ethropelvic ligaments was thinner in subjects with SUI than in non-SUI subj ects. Maximal urethral closure pressure (MUCP) was also significantly small er in subjects with SUI than in non-SUI subjects. Pressure transmission rat io (PTR) was lower in subjects with type 1, 2 and 3 SUI than in subjects wi th type 0 SUI and no SUI. Pelvic floor contractility was significantly lowe r for subjects with type 3 SUI than for the other groups of subjects. Leak point pressure (LPP) showed a significantly progressive decrease from type 1 to 3 SUI subjects. Conclusions: This study found that SUI in women is a condition in which the urethral and paraurethral structures become progressively deficient. The i ntrinsic and extrinsic structural deficiencies result in a lower MUCP, smal ler PTR, insufficient pelvic floor contractility on the urethra, and a lowe r LPP in SUI patients. Copyright (C) 2000 S. Karger AG, Basel.