Dynamic Ultrasound Evaluation of Pelvic Floor Support Biomechanics After Transvaginal Mesh Implantation

Quantitative evaluation of biomechanical changes in the pelvic floor support system following transvaginal mesh (TVM) implantation using dynamic pelvic floor ultrasound (PFUS), and exploration of the correlation between these changes and tissue repair outcomes, clinical symptom improvement, and the risk of postoperative complications. A retrospective analysis was conducted on 91 patients who underwent pelvic floor reconstruction surgery, divided into a TVM group (n=53) and a non-mesh traditional repair control group (n = 38). Dynamic pelvic floor ultrasound was used to measure the levator hiatus area (LHA), bladder neck descent (BND), retrovesical angle (RVA), and levator ani muscle integrity at rest, during the Valsalva maneuver, and during contraction. Biomechanical parameters such as pelvic floor surrogate tissue deformation index, surrogate support rigidity index, and load-bearing capacity were evaluated. Compared with the control group, the TVM group showed a more significant reduction in LHA during the Valsalva maneuver (ΔLHA reduction = 5.9 cm 2 vs. 3.3 cm 2 , P < 0.05) and a higher rate of levator ani muscle tear repair (89.5% vs. 57.1%, P = 0.011), indicating that TVM implantation effectively reduces pelvic floor surrogate tissue deformation index and improves load transfer efficiency. Additionally, the TVM group demonstrated better bladder neck stability and more favorable correction of the retrovesical angle. A combined concurrent association analysis based on postoperative PFUS parameters showed good discriminative ability for concurrent postoperative complications (Bootstrap-corrected AUC = 0.97; single-parameter AUC range: 0.88-0.96), though external validation is required to confirm generalizability. Preoperative LHA > 32.5 cm 2 or severe levator ani muscle tear were associated with TVM efficacy (AUC = 0.85). During the 3-month postoperative follow-up, transvaginal mesh repair demonstrated more favorable surrogate deformation index and surrogate support stiffness index compared with conventional autologous tissue repair, reflecting short-term imaging correlations. Dynamic pelvic floor ultrasound, utilizing geometric surrogate mechanical indices, may serve as an exploratory tool for biomechanical comparison, providing an objective and noninvasive imaging modality for preliminary postoperative efficacy assessment. These findings are based on simplified surrogate indices and short-term data, and long-term follow-up is still warranted to monitor delayed mesh-related complications.