Objective  To explore the feasibility of transluminal dual plane ultrasound (TDPU) in evaluating the structure and function of pelvic floor muscle. Methods  Non anorectal diseases patients who visited the Department of Medical Ultrasound, West China Hospital of Sichuan University, medical staff and medical staff’s relatives volunteers between May and November 2022 were selected. According to the criteria for ultrasound diagnosis of pelvic organ prolapse (POP) and the pelvic organ prolapse quantification (POP-Q) scoring criteria, the subjects were divided into normal group and POP group. The changes of the thickness of the left and right puborectalis muscle (PRM), the internal anal sphincter (IAS) and the external anal sphincter (EAS) at 3-, 6- and 9-o’clock, the depth and height of the perineal body (PB) were compared, and the changes of the elastic Young’s modulus of PRM, EAS and PB were compared through real-time shear wave elastography. Results  A total of 192 subjects were included, including 140 in the normal group and 52 in the POP group. There were statistically significant differences between the POP group and the normal group in terms of gestational frequency, parity, and history of vaginal delivery (P<0.05). There was no statistically significant difference in age, body mass index, menopausal history, and neonatal weight between the two groups (P>0.05). Under the condition of resting and maximum anal constriction, the thickness of PRM on the left and right sides of POP group was not significantly different from that of the normal group (P>0.05), but the elastic Young’s modulus of PRM on the left and right sides were lower than that of the normal group (P<0.05). At resting and maximum anal constriction, there was no significant difference in IAS thickness between the POP group and the normal group at 3-, 6- and 9-o’clock (P>0.05). At resting and maximum anal constriction, the thickness of deep and subcutaneous parts of EAS at 6-o’clock and the subcutaneous part of EAS at 9-o’clock in the POP group were smaller than those in the normal group (P<0.05). At resting and maximum anal constriction, the elastic Young’s modulus of EAS at 3-, 6- and 9-o’clock were lower than those in the normal group (P<0.05). There was no significant difference in the depth and height of PB between the POP group and the normal group at resting and maximum anal constriction (P>0.05). The elastic Young’s modulus of PB in the POP group was lower than that of the normal group (P<0.05). Under the condition of maximum anal constriction, the thickness of deep and subcutaneous parts of EAS at 3-o’clock in the POP group were lower than those in the normal group (P<0.05). Conclusion  TDPU can quantitatively evaluate the structure and function of pelvic floor muscle through different states of resting and maximum anal constriction, and also can provide ultrasonic basis for the diagnosis and treatment of female pelvic floor dysfunction diseases.

Citation： YANG Linhua, LUO Yuan, JING Jigang, ZHUANG Hua, LI Yongzhong. Evaluation of pelvic floor muscle structure and function by transluminal dual plane ultrasound. West China Medical Journal, 2023, 38(4): 559-566. doi: 10.7507/1002-0179.202212003 Copy