关键词: 压力性尿失禁； ,  , TVT； ,  , TVT-O； ,  , 有限元分析； ,  , 生物力学

Abstract: Objective   To simulate common sling surgeries for stress urinary incontinence (SUI) in elderly women using finite element analysis methods: tension-free vaginal tape (TVT) and tension-free vaginal tape - obturator (TVT-O), and to evaluate their therapeutic effects at different positions of urethra. Methods    A pelvic geometry model was constructed based on magnetic resonance imaging (MRI) images of a woman without pelvic floor diseases. The thinning of elderly vaginal tissue was considered as a reduction in tissue stiffness. Abdominal pressure was applied to simulate valsalva maneuver, and TVT and TVT-O were placed at the proximal, mid-distal, and distal parts of urethra, respectively, to obtain mechanical data. Results    The sling at the proximal part of urethra would lead to the α-angle and bladder neck displacement less than normal values. The "funnel" phenomenon disappeared when the sling was located at the proximal and mid-distal parts of urethra, but still existed when located at the distal part; the pressure magnitude between the sling and urethra at different positions was: proximal > mid-distal > distal.   Conclusions   The sling at the proximal part of urethra (30%) is prone to cause excessive tightness of urethra, leading to postoperative complications, the sling at the distal part of urethra (80%) has poor therapeutic effect, the sling at the mid-distal part of urethra (60%) has a good therapeutic effect and a low incidence of postoperative complications. The placement of TVT at the mid-distal part of urethra should be the preferred surgical method for elderly women with SUI.

Key words: Stress urinary incontinence; ,  ,  TVT; ,  ,  TVT-O; ,  ,  Finite element analysis; ,  , Biomechanics