Transperineal ultrasound measurement of the levator plate angle and anorectal angle is a useful method for evaluating uterine prolapse : a prospective cohort study

Transperineal ultrasound measurement of the levator plate angle and anorectal angle is a useful method for evaluating uterine prolapse : a prospective cohort study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Transperineal ultrasound measurement of the levator plate angle and anorectal angle is a useful method for evaluating uterine prolapse : a prospective cohort study Jiangfeng Dai, Shunlan Liu, Jiawen Li, Shijie Zhang, Wu Xu, Guorong Lyu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4535033/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Confirming the patient's cervical position using transperineal ultrasound is not an easy task. This study aimed to employ transperineal ultrasound to measure the levator plate angle (LPA) and anorectal angle (ARA) in patients with varying degrees of uterine prolapse and to explore their efficacy in assessing uterine prolapse. Methods This prospective study consecutively enrolled 130 female patients who underwent examinations for lower urinary tract or pelvic floor dysfunction symptoms at the Second Affiliated Hospital of Fujian Medical University from August 2022 to December 2023. Participants were divided into three groups based on the Pelvic Organ Prolapse Quantification (POP-Q) system: POP-Q = 0 (n = 45), POP-Q = 1 (n = 45), and POP-Q ≥ 2 (n = 40). Transperineal ultrasound was used to measure the LPA and ARA at rest (rLPA and rARA) and during maximum Valsalva maneuver (vLPA and vARA). Changes in LPA and ARA from rest to maximal Valsalva (ΔLPA and ΔARA) were calculated. The differences in these ultrasound parameters among the three groups were compared. The area under the curve (AUC) was calculated to assess the diagnostic performance. Results With increasing severity of uterine prolapse, vLPA decreased progressively, while vARA and ΔARA initially decreased and then increased ( P < 0.05). Compared with the POP-Q stage = 0 group, rLPA was reduced in the POP-Q stage ≥ 2 group, and ΔLPA was reduced in the POP-Q stage = 1 and POP-Q stage ≥ 2 groups ( P < 0.05). The optimal cutoff values for diagnosing POP-Q stage ≥ 1 were 27.01° for rLPA, -2.29° for vLPA, and − 26.11° for ΔLPA, with corresponding AUCs of 0.65, 0.86, and 0.75. For diagnosing POP-Q stage ≥ 2, the optimal cutoff values were 24.11° for rLPA, -6.97° for vLPA, and − 34.57° for ΔLPA, with corresponding AUCs of 0.67, 0.80, and 0.69. DeLong's test indicated that vLPA had the highest efficacy in diagnosing both POP-Q stage ≥ 1 and POP-Q stage ≥ 2 ( P < 0.05). Conclusion Transperineal ultrasound measurement of the LPA and ARA is a simple and effective method for assessing uterine prolapse. Uterine prolapse ultrasound examination levator plate angle anorectal angle Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Pelvic organ prolapse (POP) is a common condition that can significantly impact patients' quality of life ( 1 , 2 ). The current clinical standard for assessing the severity of POP is the International Continence Society Pelvic Organ Prolapse Quantification system (ICS POP-Q), established in 1996 ( 3 ). However, this evaluation system is highly subjective and only provides information on the surface-level anatomical features, without insight into the deeper organ structures or functional anatomy( 2 ). Transperineal ultrasound (TPUS) has emerged as a modality that can complement the limitations of the POP-Q system ( 4 ). TPUS has been widely utilized for the quantification of pelvic organ prolapse ( 4 , 5 ). This technique is safe, simple, and demonstrates good reproducibility ( 6 – 9 ). To assess uterine prolapse using TPUS, two key reference lines need to be identified: one at the level of the inferior margin of the pubic symphysis, and another horizontal line through the anterior cervical lip, which is used to determine the position of the uterus on ultrasound ( 4 ). However, the uterus typically exhibits medium-level echogenicity, similar to the vaginal wall ( 10 ), particularly in postmenopausal women with a small, atrophic uterus, where the anterior cervical lip can be difficult to visualize. Interposition of bowel or rectal contents can also lead to incomplete imaging of the cervix and fornices ( 5 ). While the inferior aspect of the cervix or the vaginal gas or cervical Nabothian cysts may be used as landmarks, these can be challenging for the novice sonographer, and Nabothian cysts are not present in all patients. Therefore, alternative methods to diagnose uterine prolapse when the cervix is not clearly visualized on TPUS would be valuable. The levator ani muscle (LAM) plays a key role in supporting the pelvic organs ( 11 – 13 ). The levator plate angle (LPA) reflects the degree of inclination of the levator plate, and changes in the LPA with contraction and relaxation of the LAM correspond to the functional status of the LAM ( 14 , 15 ). The anorectal angle (ARA) is considered an important parameter for evaluating anorectal function, and the changes in ARA during maximal squeeze and Valsalva maneuvers are thought to reflect the functional state of the pelvic floor muscles ( 16 ). Previous studies have shown that ultrasound and defecography provide comparable measurements of the ARA ( 17 ). Therefore, we hypothesized that TPUS measurements of the LPA and ARA could provide diagnostic information for uterine prolapse. Based on the hypothesis above, this study aims to investigate the relationship between LPA and ARA measured by TPUS in different states and the severity of uterine prolapse. We anticipate that these measurements will provide valuable diagnostic indicators for uterine prolapse diagnosis. Materials and methods Study Design This prospective study consecutively enrolled patients who underwent POP-Q and TPUS examinations at the Second Affiliated Hospital of Fujian Medical University for symptoms of lower urinary tract or pelvic floor dysfunction from August 2022 to December 2023. The flowchart of the study population enrollment is shown in Fig. 1 . This study was approved by the institutional review boards of the Second Affiliated Hospital of Fujian Medical University (No. 2021–012). All subjects volunteered to participate and provided signed informed consent. The POP-Q examinations were performed by experienced gynecologists (with ≥ 2 years of ICS POP-Q examination experience), who were blinded to the participants' clinical information and ultrasound findings. The exclusion criteria were: (a) women aged < 18 years; (b) poor image quality that did not allow for complete visualization of the levator plate and pubic bone; (c) inability to perform a valid Valsalva maneuver or presence of levator muscle coactivation during the Valsalva maneuver ( 18 ); (d) history of large pelvic masses or pelvic-related surgeries; (e) pelvic floor dysfunction syndrome ( 19 ); (f) Women with predominant anterior or posterior vaginal wall prolapse. For women with multi-compartment prolapse, if uterine prolapse was at the same POP-Q stage as anterior or posterior vaginal wall prolapse, they were included. A total of 130 women were finally included in the study, with 45 in the POP-Q = 0 group, 45 in the POP-Q = 1 group, and 40 in the POP-Q ≥ 2 group. Transperineal Ultrasound Assessment Transperineal ultrasound was performed using the GE Voluson E8 or E10 ultrasound device (GE Healthcare, Zipf, Austria) with 4-8MHz curved array volume transducer and with an acquisition angle of 85°. Before the examination, participants were instructed to empty their bladder and bowel as much as possible and were trained to sustain a Valsalva maneuver for at least 6 seconds. The participants were examined in the lithotomy position, with the perineum fully exposed. The probe was placed on the median sagittal plane, and the images were adjusted until the inferior margin of the symphysis pubis, cervix, anorectal junction, and the posterior levator ani muscle were clearly visualized (Fig. 2 ). Each participant maintained the Valsalva maneuver for at least 6 seconds, and no levator muscle coactivation was observed (Fig. 3 ). Measurements included the LPA and ARA at rest (rLPA and rARA) and at maximal Valsalva maneuver (vLPA and vARA). The change in LPA from rest to maximal Valsalva (ΔLPA) was calculated as vLPA minus rLPA, and the change in ARA from rest to maximal Valsalva (ΔARA) was calculated as vARA minus rARA. The LPA was defined as the angle between the horizontal line at the inferior margin of the symphysis pubis and the line connecting the inferior margin of the symphysis pubis and the anorectal junction ( 20 ). The LPA was considered negative when the anorectal junction was located above the inferior margin of the symphysis pubis and positive when it was located below. The ARA is defined as the angle between the posterior wall of the rectum and the central axis of the anal canal ( 21 – 23 ). Two ultrasound physicians with identical qualifications repeated the measurements on the same ultrasound device. They were blinded to the clinical data and POP-Q stage of the participants before the examination. An ultrasound physician who did not participate in the study assisted in recording and obscuring the measurement values displayed on the screen, so the examining physicians were unaware of their own measurement values. Examiner A first performed the examination and measurements, followed by Examiner B 0.5 hours later, and then Examiner A again 0.5 hours later. The intraclass correlation coefficient (ICC) was used to evaluate the intra- and inter-observer reliability of the LPA and ARA measurements. Statistical Analysis Statistical analysis of the data was conducted using SPSS version 26.0 software for Windows (SPSS Inc, Chicago, IL, USA). Normality was assessed using the Shapiro-Wilk test. Data with normal distribution are presented as mean ± standard deviation ( x ± s ), and differences were analyzed using one-way analysis of variance. Non-normally distributed data are presented as median (interquartile range), and differences were analyzed using the Kruskal-Wallis H test. Bonferroni correction was applied for pairwise comparisons. Categorical data were presented as n ( % ) and compared using the chi-square test. The reliability of intra- and inter-observer measurements was assessed using the ICC with a 95% confidence interval. Correlation analysis was performed using Spearman's method, with |r| ≥ 0.8 indicating a high correlation, 0.5 ≤ |r| < 0.8 indicating a moderate correlation, 0.3 ≤ |r| < 0.5 indicating a low correlation, and 0 < |r| < 0.3 indicating a weak correlation. Receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was calculated. The DeLong test was used to compare the diagnostic performance, and the Youden index was used to determine the optimal cutoff value. For all analyses, P < 0.05 was considered statistically significant. Results Repeatability analysis of LPA and ARA measurements by transperineal ultrasound The intra- and inter-observer reproducibility of LPA and ARA measurements by the same physician and different physicians with the same qualifications under different conditions are shown in Table 1 . The results showed that the measurements of LPA and ARA under different conditions by the same physician or different physicians with the same qualifications had good consistency and repeatability, with ICC values all exceeding 0.83. Table 1 Intra-observer and inter-observer reproducibility of ultrasonographic measurements Measure Intra-observer reproducibility (n = 20) Inter-observer reproducibility (n = 20) ICC (95%CI) rLPA 0.987(0.968–0.995) 0.962(0.907–0.985) vLPA 0.962(0.907–0.985) 0.952(0.882–0.981) ∆LPA 0.977(0.943–0.991) 0.964(0.910–0.986) rARA 0.886(0.735–0.953) 0.868(0.696–0.945) vARA 0.858(0.676–0.941) 0.837(0.634–0.932) ∆ARA 0.953(0.882–0.982) 0.934(0.833–0.974) ICC, intraclass correlation coefficient; CI, confidence interval; rLPA, levator plate angle at rest; vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rARA, anorectal angle at rest; vARA, anorectal angle during maximum Valsalva maneuver; ∆ARA, change in anorectal angle from rest to maximal Valsalva. Comparison of clinical data and transperineal ultrasound measurement data The baseline demographic characteristics and transperineal ultrasound measurements of the study population are shown in Table 2 . There were statistically significant differences among the three groups in terms of average age, parity, history of vaginal delivery, menopausal status, and urinary incontinence symptoms ( P < 0.05). As the severity of uterine prolapse increased, vLPA gradually decreased ( P < 0.05). Compared to POP-Q stage = 0, rLPA decreased in the POP-Q stage ≥ 2, and both the POP-Q stage = 1 and POP-Q stage ≥ 2 showed a decrease in ΔLPA ( P < 0.05), as shown in Fig. 4 . With the increasing severity of uterine prolapse, vARA and ΔARA initially decreased and then increased ( P < 0.05); however, there was no statistically significant difference in rARA among different degrees of uterine prolapse ( P = 0.151), as shown in Fig. 5 . Spearman correlation analysis revealed a moderate negative correlation between the degree of uterine prolapse and vLPA ( r = -0.621, P < 0.001), and a low negative correlation between the degree of uterine prolapse and rLPA, ΔLPA ( r = -0.305, P < 0.001; r = -0.420, P < 0.001). Table 2 Clinical data and transperineal ultrasound measurements of the study population General Clinical and Ultrasonic Data POP-Q stage = 0 (n = 45) POP-Q stage = 1 (n = 45) POP-Q stage ≥ 2 (n = 45) F/H/X 2 P value Age (years) 36.11 ± 6.05 43.44 ± 9.36 45.68 ± 10.42 14.22 < 0.001 Parity (times) 1.47 ± 0.76 1.98 ± 0.94 1.82 ± 0.71 4.67 0.011 Vaginal delivery history 19(42.2%) 41(91.1%) 37(92.5%) 38.15 < 0.001 Menopausal 8(17.8%) 22(48.9%) 19(47.5%) 11.64 0.003 Urinary incontinence 9(20.0%) 23(51.1%) 17(42.5%) 9.84 0.007 rLPA (°) 25.47 ± 7.12 23.14 ± 6.71 20.10 ± 6.39 6.70 0.002 vLPA (°) 1.70(8.57) -9.19(10.96) -16.08(12.45) 50.86 < 0.001 ∆LPA (°) -23.41 ± 9.12 31.04 ± 9.34 -34.17 ± 10.26 14.47 < 0.001 rARA (°) 109.51(9.31) 111.73(9.79) 109.48(8.91) 3.78 0.151 vARA (°) 112.30(6.79) 103.33(10.00) 121.39(15.57) 45.03 < 0.001 ∆ARA (°) 4.17(3.20) -8.31(10.63) 11.52(6.82) 74.99 < 0.001 Data are presented as means ± standard deviations or median (interquartile range) or frequencies and percentages in parentheses. rLPA, levator plate angle at rest; vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rARA, anorectal angle at rest; vARA, anorectal angle during maximum Valsalva maneuver; ∆ARA, change in anorectal angle from rest to maximal Valsalva. Diagnostic efficacy of rLPA, vLPA, and ΔLPA for the severity of uterine prolapse The diagnostic efficacy of transperineal ultrasound parameters in assessing the severity of uterine prolapse is presented in Table 3 . DeLong's test showed that vLPA had the best efficacy in diagnosing POP-Q stage ≥ 1, (vLPA vs rLPA, Z = 3.679, P < 0.05; vLPA vs ΔLPA, Z = 3.070, P < 0.05) and POP-Q stage ≥ 2, (vLPA vs rLPA, Z = 2.282, P = 0.023; vLPA vs ΔLPA, Z = 3.178, P = 0.002). The optimal cutoff value of vLPA for diagnosing POP-Q stage ≥ 1 was − 2.29°, with a sensitivity of 0.87 and a specificity of 0.82. For POP-Q stage ≥ 2, the optimal cutoff value of vLPA was − 6.97°, with a sensitivity of 0.85 and a specificity of 0.68. Figures 6 and 7 display the ROC curves for rLPA, vLPA, and ΔLPA in diagnosing POP-Q stage ≥ 1 and POP-Q stage ≥ 2. Table 3 Accuracy of parameters measured by transperineal ultrasound in diagnosing the severity of uterine prolapse Parameter Cutoff value(°) AUC(95% CI) Sensitivity(95% CI) Specificity(95% CI) LR + LR - POP-Q stage ≥ 1 vLPA -2.29 0.86(0.78–0.91) 0.87(0.78–0.93) 0.82(0.68–0.92) 4.90 0.16 ∆LPA -26.31 0.75(0.67–0.82) 0.79(0.69–0.87) 0.62(0.47–0.76) 2.09 0.34 rLPA 27.01 0.65(0.57–0.74) 0.84(0.74–0.91) 0.49(0.34–0.64) 1.63 0.34 POP-Q stage ≥ 2 vLPA -6.97 0.80(0.72–0.87) 0.85(0.70–0.94) 0.68(0.57–0.77) 2.64 0.22 ∆LPA -34.57 0.69(0.60–0.77) 0.55(0.39–0.71) 0.79(0.69–0.87) 2.61 0.57 rLPA 24.11 0.67(0.58–0.75) 0.78(0.62–0.89) 0.52(0.41–0.63) 1.62 0.43 POP-Q, pelvic organ prolapse quantification; AUC, area under the receiver operating characteristic curve; CI, confidence interval; LR, likelihood ratio. Discussion The results of this study demonstrate that the intra- and inter-observer reliability of transperineal ultrasound measurements of LPA and ARA in the resting and Valsalva states were excellent, with ICC values all exceeding 0.83, consistent with previous studies ( 24 – 26 ). This indicates that the assessment of LPA and ARA is a feasible approach for evaluating the severity of uterine prolapse. Our study found that as the severity of uterine prolapse increased, the values of vLPA, rLPA, and ΔLPA gradually decreased. Spearman correlation analysis revealed a moderate negative correlation between the degree of uterine prolapse and vLPA, and a weak negative correlation between the degree of uterine prolapse and rLPA, ΔLPA. The LAM is a critical muscle group supporting pelvic floor organs, and its contraction and relaxation lead to the up-and-down movement of the levator plate, resulting in changes in the LPA angle. The stronger the contraction ability of the LAM, the greater the changes in the angle ( 14 ). In their study of pelvic floor disorders, Jeong et al ( 27 ) found that an increase in the scores for LAM deficiency was associated with changes in the static pelvic shape at rest, with the levator plate moving downward towards the perineum, leading to a decrease in LPA. Additionally, there was a moderate negative correlation between levator ani muscle deficiency scores and LPA at rest ( r = -0.528, P < 0.05). Hoyte et al ( 28 ) found that the vLPA was decreased in the prolapse group compared to the non-prolapse group. Qiu et al ( 29 )also reported that ΔLPA decreased with increasing POP-Q scores for posterior vaginal wall prolapse using dynamic MRI analysis. Our study supports these previous findings. Additionally, we established the optimal cutoff values for the diagnosis of uterine prolapse in POP-Q stage ≥ 1 and POP-Q stage ≥ 2 by transperineal ultrasound measurement of LPA in different states. Among these, the efficacy of vLPA was the highest. When the vLPA value was less than − 2.29°, the sensitivity and specificity for diagnosing POP-Q stage ≥ 1 were 0.87 and 0.82. Similarly, when the vLPA value was less than − 6.97°, the sensitivity and specificity for diagnosing POP-Q stage ≥ 2 were 0.85 and 0.68. These results indicate that vLPA can be effectively used to assess the severity of uterine prolapse. Currently, in the assessment of uterine prolapse using transperineal ultrasound, the distance from the horizontal line located at the lower edge of the pubic symphysis to the horizontal line at the anterior edge of the cervix is commonly used. However, identifying the position of the cervix is often challenging. In contrast, the measurement of the levator plate angle is less susceptible to interference from other factors and appears clearer in transperineal ultrasound examinations. Interestingly, we found that in patients with POP-Q stage = 1, both vARA and ΔARA decreased compared to those POP-Q stage = 0 and POP-Q stage ≥ 2, whereas in patients with POP-Q stage ≥ 2, ARA increased compared to POP-Q stage = 0. Anatomically, the LAM wraps around the rectoanal junction from the posterior aspect and provides cranial elevation of the rectoanal junction. Disruption of the LAM leads to increased ARA, as the normal posterior rectal contour cannot be maintained without the proper insertion of the LAM ( 30 ). This results in an increase in ARA during Valsalva maneuver ( 31 ). In patients with POP-Q stage = 1, the expansion of the levator ani muscle's hiatus during the Valsalva maneuver is more significant compared to those without prolapse, theoretically resulting in a larger ARA, but in our research, this was not the case. The reasons behind these results may be as follows: During the Valsalva maneuver in patients with POP-Q stage = 1, the uterus may not exhibit significant descent. Due to the weakened uterine fascia and ligaments, the uterus is prone to posterior downward movement, pressing the rectum toward the sacrum, resulting in a decrease in ARA (Fig. 3 B). Additionally, in patients with uterine prolapse accompanied by bladder prolapse, since the main prolapsed component is the uterus, the degree of descent of the bladder is also limited and tends to move posteriorly. Although the uterus is in between, it may still exert pressure on the rectum, causing a decrease in ARA. However, in patients with POP-Q stage ≥ 2, the uterus primarily descends downward or even protrudes externally. At this stage, apart from the more pronounced dilation of the levator ani muscle hiatus, there is also compression of the rectovaginal septum by the prolapsed uterus, resulting in an increase in ARA (Fig. 3 C). Therefore, we believe that vARA and ΔARA may provide some reference value in the assessment of uterine prolapse. This study excluded women with predominant anterior or posterior compartment prolapse and those with levator ani muscle coactivation or pelvic floor dysfunction, thereby avoiding the confounding effects of these factors. However, there are limitations to this study. It is a single-center study with a small sample size, and it did not include questionnaire surveys or defecography examinations for all patients to assess bowel function. Therefore, it is unclear whether there are differences in bowel control among the three groups of patients. Conclusion Transperineal ultrasound measurement of LPA is an effective method for evaluating uterine prolapse. Specifically, LPA assessment during Valsalva maneuver demonstrates the best diagnostic performance and could be incorporated as a new parameter in the transperineal ultrasound evaluation. ARA exhibits variations corresponding to different stages of uterine prolapse, and can be used as a supplementary reference in the assessment of uterine prolapse. Abbreviations POP Pelvic organ prolapse ICS POP-Q International Continence Society Pelvic Organ Prolapse Quantification system LAM levator ani muscle TPUS Transperineal ultrasound LPA Levator plate angle ARA Anorectal angle ICC Intraclass correlation coefficient ROC Receiver operating characteristic AUC Area under the curve Declarations Acknowledgments: Not applicable. Ethics approval and consent to participate: Participants in this study were fully informed about the study’s aims and protocol. Written informed consent was obtained from all participants. Ethical approval for this prospective data collection study was obtained from the Institutional Review Board of the Second Affiliated Hospital of Fujian Medical University (No. 2021 - 012). All procedures were in accordance with ethical standards and the Declaration of Helsinki. Consent for publication: Not Applicable. Availability of data and materials: The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to their containing information that could compromise the privacy of research participants. Competing interests: The authors declare no competing interests. Funding: This work was supported by the Fujian Provincial Health Commission science and technology plan project (2022CXB010) Authors' contributions: SZ.H. and GR.L. were responsible for the project design and manuscript revision; JF.D., SL.L. and SJ.Z. are responsible for data collation and statistics; JF.D., JW.L. and W.X. are responsible for manuscript writing; All authors reviewed the manuscript. References Raju R, Linder BJ. Evaluation and Management of Pelvic Organ Prolapse. Mayo Clinic Proceedings. 2021;96(12):3122-9. Shek KL, Dietz HP. Assessment of pelvic organ prolapse: a review. Ultrasound Obstet Gynecol. 2016;48(6):681–92. Madhu C, Swift S, Moloney-Geany S, Drake MJ. How to use the Pelvic Organ Prolapse Quantification (POP-Q) system? Neurourol Urodyn. 2018;37(S6):S39–43. Dietz HP. Ultrasound in the assessment of pelvic organ prolapse. Best Pract Res Clin Obstet Gynaecol. 2019;54:12–30. Dietz HP, Haylen BT, Broome J. Ultrasound in the quantification of female pelvic organ prolapse. Ultrasound Obstet Gynecol. 2001;18(5):511–4. Tan L, Shek KL, Atan IK, Rojas RG, Dietz HP. The repeatability of sonographic measures of functional pelvic floor anatomy. Int Urogynecol J. 2015;26(11):1667–72. Dietz HP, Rojas RG, Shek KL. Postprocessing of pelvic floor ultrasound data: how repeatable is it? Aust N Z J Obstet Gynaecol. 2014;54(6):553–7. Siafarikas F, Staer-Jensen J, Braekken IH, Bo K, Engh ME. Learning process for performing and analyzing 3D/4D transperineal ultrasound imaging and interobserver reliability study. Ultrasound Obstet Gynecol. 2013;41(3):312–7. Turel Fatakia F, Subramaniam N, Bienkiewicz J, Friedman T, Dietz HP. How repeatable is assessment of external anal sphincter trauma by exoanal 4D ultrasound? Ultrasound Obstet Gynecol. 2019;53(6):836–40. Dietz HP. Pelvic floor ultrasound: a review. Am J Obstet Gynecol. 2010;202(4):321–34. Azpiroz F, Fernandez-Fraga X, Merletti R, Enck P. The puborectalis muscle. Neurogastroenterol Motil. 2005;17(Suppl 1):68–72. Blomquist JL, Carroll M, Munoz A, Handa VL. Pelvic floor muscle strength and the incidence of pelvic floor disorders after vaginal and cesarean delivery. Am J Obstet Gynecol. 2020;222(1):62. e1- e8. Rodrigues AA Jr., Bassaly R, McCullough M, Terwilliger HL, Hart S, Downes K, et al. Levator ani subtended volume: a novel parameter to evaluate levator ani muscle laxity in pelvic organ prolapse. Am J Obstet Gynecol. 2012;206(3):e2441–9. Davis SN, Morin M, Binik YM, Khalife S, Carrier S. Use of pelvic floor ultrasound to assess pelvic floor muscle function in Urological Chronic Pelvic Pain Syndrome in men. J Sex Med. 2011;8(11):3173–80. Raizada V, Mittal RK. Pelvic floor anatomy and applied physiology. Gastroenterol Clin North Am. 2008;37(3):493–509. vii. Putz C, Alt CD, Wagner B, Gantz S, Gerner HJ, Weidner N, et al. MR defecography detects pelvic floor dysfunction in participants with chronic complete spinal cord injury. Spinal Cord. 2020;58(2):203–10. Yao YB, Yin HQ, Wang HJ, Liang HT, Wang B, Wang C. Is the transperineal ultrasonography approach effective for the diagnosis of rectocele? Gastroenterol Rep. 2021;9(5):461–9. Orno AK, Dietz HP. Levator co-activation is a significant confounder of pelvic organ descent on Valsalva maneuver. Ultrasound Obstet Gynecol. 2007;30(3):346–50. Li M, Jiang T, Peng P, Yang X. MR Defecography in Assessing Functional Defecation Disorder: Diagnostic Value of the Defecation Phase in Detection of Dyssynergic Defecation and Pelvic Floor Prolapse in Females. Digestion. 2019;100(2):109–16. Nam G, Song JY, Lee SR. A New Angle Measurement in Translabial Ultrasound as an Adjunct for the Diagnosis of Pelvic Organ Prolapse. Diagnostics (Basel Switzerland). 2022;12(1). Roos JE, Willmann JK, Weishaupt D, Lachat M, Marincek B, Hilfiker PR. Thoracic aorta: motion artifact reduction with retrospective and prospective electrocardiography-assisted multi-detector row CT. Radiology. 2002;222(1):271–7. Choi JS, Wexner SD, Nam YS, Mavrantonis C, Salum MR, Yamaguchi T, et al. Intraobserver and interobserver measurements of the anorectal angle and perineal descent in defecography. Dis Colon Rectum. 2000;43(8):1121–6. Jorge JM, Wexner SD, Marchetti F, Rosato GO, Sullivan ML, Jagelman DG. How reliable are currently available methods of measuring the anorectal angle? Dis Colon Rectum. 1992;35(4):332–8. Rostaminia G, White DE, Quiroz LH, Shobeiri SA. Levator plate descent correlates with levator ani muscle deficiency. Neurourol Urodyn. 2015;34(1):55–9. Lone F, Sultan AH, Stankiewicz A, Thakar R. Interobserver agreement of multicompartment ultrasound in the assessment of pelvic floor anatomy. Br J Radiol. 2016;89(1059):20150704. García-Mejido JA, García Pombo S, Fernández-Conde C, Fernández-Palacín A, Borrero C, Sainz-Bueno JA. Reproducibility of the anorectal angle with transperineal ultrasound. Quant imaging Med Surg. 2023;13(3):1664–71. Jeong HY, Park DH, Lee JK. Levator plate descent angle in pelvic floor disorders. Tech Coloproctol. 2021;25(9):1011–8. Hoyte L, Schierlitz L, Zou K, Flesh G, Fielding JR. Two- and 3-dimensional MRI comparison of levator ani structure, volume, and integrity in women with stress incontinence and prolapse. Am J Obstet Gynecol. 2001;185(1):11–9. Qiu Z, Song Y. A Hypothesis Generating the Mechanical Systems Underlying Posterior Vaginal Prolapse Based on Observed Displacements by Dynamic Magnetic Resonance Imaging. Female Pelvic Med Reconstr Surg. 2020;26(9):585–90. García-Mejido JA, García-Pombo S, Fernández-Conde C, Borrero C, Fernández-Palacín A, Sainz-Bueno JA. The Role of Transperineal Ultrasound for the Assessment of the Anorectal Angle and Its Relationship with Levator Ani Muscle Avulsion. Tomography. 2022;8(3):1270–6. Cyr MP, Kruger J, Wong V, Dumoulin C, Girard I, Morin M. Pelvic floor morphometry and function in women with and without puborectalis avulsion in the early postpartum period. Am J Obstet Gynecol. 2017;216(3):274. e1- e8. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4535033","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":314750043,"identity":"b62523ef-2a66-4c5a-a60c-a8536050f51b","order_by":0,"name":"Jiangfeng Dai","email":"","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jiangfeng","middleName":"","lastName":"Dai","suffix":""},{"id":314750044,"identity":"59fd2342-7014-4c3f-950c-48c6a7609a9a","order_by":1,"name":"Shunlan Liu","email":"","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shunlan","middleName":"","lastName":"Liu","suffix":""},{"id":314750045,"identity":"13585c95-5a0b-4c15-83ff-b44a536310d4","order_by":2,"name":"Jiawen Li","email":"","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jiawen","middleName":"","lastName":"Li","suffix":""},{"id":314750047,"identity":"14568c40-7082-42f5-89f9-3ae9cedebda5","order_by":3,"name":"Shijie Zhang","email":"","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shijie","middleName":"","lastName":"Zhang","suffix":""},{"id":314750049,"identity":"b2b7e8f1-453e-41ab-9ea4-610d368c8731","order_by":4,"name":"Wu Xu","email":"","orcid":"","institution":"Fujian Provincial Maternity and Children's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Wu","middleName":"","lastName":"Xu","suffix":""},{"id":314750051,"identity":"e1e053c6-9826-4300-b4ea-3049f8fd4f17","order_by":5,"name":"Guorong Lyu","email":"","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Guorong","middleName":"","lastName":"Lyu","suffix":""},{"id":314750053,"identity":"35f2aa5c-b325-4e20-ad0a-a595fea361a0","order_by":6,"name":"Shaozheng He","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsklEQVRIiWNgGAWjYBACAwYGNgbGBhs5flK1pBlLNpCo5XDihgPEajFnb3/28OeOw8bGx5M3MPyo2EZYi2XPGXMDyTPpcmZnnhUw9py5TYTDbuSwSRi2WRub3cgxYGZsI0bL/efPJBLbmBM3zyBayw0GM4mDbc6JGySI1nImx0yysS3NWALol4PE+eX48WeSP9uAUdmevPHBjwoitCCBBIMDJKkHayFVxygYBaNgFIwQAACHkj7Ut4fdvAAAAABJRU5ErkJggg==","orcid":"","institution":"The Second Affiliated Hospital of Fujian Medical University","correspondingAuthor":true,"prefix":"","firstName":"Shaozheng","middleName":"","lastName":"He","suffix":""}],"badges":[],"createdAt":"2024-06-05 15:08:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4535033/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4535033/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":59216162,"identity":"982b79ef-7461-4579-9655-e80447b23171","added_by":"auto","created_at":"2024-06-27 19:02:14","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":230862,"visible":true,"origin":"","legend":"\u003cp\u003eA flowchart of inclusion of participant\u003c/p\u003e","description":"","filename":"Figure1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/31992c906dbe85c54711a6d2.jpeg"},{"id":59215069,"identity":"b9aa8643-288c-4e5f-ab12-519ac612a183","added_by":"auto","created_at":"2024-06-27 18:54:14","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":832449,"visible":true,"origin":"","legend":"\u003cp\u003eTransperineal ultrasound showing levator plate angle and anorectal angle in different stages of uterine prolapse at rest. Figure A, POP-Qstage = 0; figure B, POP-Q stage = 1; figure C, POP-Q stage ≥ 2; PS, pubic symphysis; LPA, levator plate angle; ARA, anorectal angle; The yellow line indicates the levator plate angle, and the green line indicates the anorectal angle.\u003c/p\u003e","description":"","filename":"Figure2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/724831fa94c7682fd520c2a8.jpeg"},{"id":59215074,"identity":"1e4d87fe-7f6d-415c-b131-c8cd883b9135","added_by":"auto","created_at":"2024-06-27 18:54:14","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":730267,"visible":true,"origin":"","legend":"\u003cp\u003eTransperineal ultrasound showing levator plate angle and anorectal angle in different stages of uterine prolapse during Valsalva maneuver. Figure A, POP-Q stage = 0; figure B, POP-Qstage = 1; figure C, POP-Qstage ≥ 2; PS, pubic symphysis; LPA, levator plate angle; ARA, anorectal angle; The yellow line indicates the levator plate angle , and the green line indicates the anorectal angle. The pink arrow indicates the direction of force exerted by the prolapsing uterus or cervix on the anterior wall of the rectum or the rectovaginal septum.\u003c/p\u003e","description":"","filename":"Figure3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/6733dfa76c88db7497bc20f5.jpeg"},{"id":59215075,"identity":"6adcc6de-9896-4819-a955-2680fde6c9c6","added_by":"auto","created_at":"2024-06-27 18:54:14","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":118035,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of levator plate angle under different conditions in uterine prolapse. rLPA, levator plate angle at rest; vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva. The middle line represents the average levator plate angle position in each stage of uterine prolapse under the different conditions. Note: *, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.05; **, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.01; ***, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; ****, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.0001; \u003cem\u003eNS\u003c/em\u003e, no statistical significance.\u003c/p\u003e","description":"","filename":"Figure4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/e19474c18feb4f1cc935af10.jpeg"},{"id":59215072,"identity":"09d13b46-4ef6-452f-9821-fdf289bee87a","added_by":"auto","created_at":"2024-06-27 18:54:14","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":161650,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of anorectal angle under different conditions in uterine prolapse. rARA, anorectal angle at rest; vARA, anorectal angle during maximum Valsalva maneuver; ∆ARA, change in anorectal angle from rest to maximal Valsalva. The middle line represents the average anorectal angle position in each stage of uterine prolapse under the different conditions. Note: *, \u003cem\u003eP \u003c/em\u003e\u0026lt;0.05; **, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.01; ***, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.001; ****, \u003cem\u003eP \u003c/em\u003e\u0026lt; 0.0001; \u003cem\u003eNS\u003c/em\u003e, no statistical significance.\u003c/p\u003e","description":"","filename":"Figure5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/51f1665e8c03f62b02e9ab2b.jpeg"},{"id":59216161,"identity":"1c0f4bd9-7511-45c0-8868-8f903a91fb83","added_by":"auto","created_at":"2024-06-27 19:02:14","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":90593,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operating characteristic (ROC) curves for diagnosing POP-Q stage ≥ 1 using rLPA, vLPA, and ∆LPA. vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rLPA, levator plate angle at rest; AUC, area under the receiver operating characteristic curve.\u003c/p\u003e","description":"","filename":"Figure6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/3c6d93b429c8a1ba94053715.jpeg"},{"id":59215070,"identity":"e2279931-661d-4b56-98c3-3d3ce5e3a1bb","added_by":"auto","created_at":"2024-06-27 18:54:14","extension":"jpeg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":90257,"visible":true,"origin":"","legend":"\u003cp\u003eReceiver operating characteristic (ROC) curves for diagnosing POP-Q stage ≥ 2 using rLPA, vLPA, and ∆LPA. vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rLPA, levator plate angle at rest; AUC, area under the receiver operating characteristic curve.\u003c/p\u003e","description":"","filename":"Figure7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/695991efe3a2de4ca9b3779b.jpeg"},{"id":82255542,"identity":"52985772-5519-483a-8626-9e196f0745cc","added_by":"auto","created_at":"2025-05-08 11:01:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3138177,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4535033/v1/25cb8840-c8d0-4164-bde0-2e4bcb977dc1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Transperineal ultrasound measurement of the levator plate angle and anorectal angle is a useful method for evaluating uterine prolapse : a prospective cohort study","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePelvic organ prolapse (POP) is a common condition that can significantly impact patients' quality of life (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). The current clinical standard for assessing the severity of POP is the International Continence Society Pelvic Organ Prolapse Quantification system (ICS POP-Q), established in 1996 (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). However, this evaluation system is highly subjective and only provides information on the surface-level anatomical features, without insight into the deeper organ structures or functional anatomy(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Transperineal ultrasound (TPUS) has emerged as a modality that can complement the limitations of the POP-Q system (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). TPUS has been widely utilized for the quantification of pelvic organ prolapse (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). This technique is safe, simple, and demonstrates good reproducibility (\u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo assess uterine prolapse using TPUS, two key reference lines need to be identified: one at the level of the inferior margin of the pubic symphysis, and another horizontal line through the anterior cervical lip, which is used to determine the position of the uterus on ultrasound (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). However, the uterus typically exhibits medium-level echogenicity, similar to the vaginal wall (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e), particularly in postmenopausal women with a small, atrophic uterus, where the anterior cervical lip can be difficult to visualize. Interposition of bowel or rectal contents can also lead to incomplete imaging of the cervix and fornices (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). While the inferior aspect of the cervix or the vaginal gas or cervical Nabothian cysts may be used as landmarks, these can be challenging for the novice sonographer, and Nabothian cysts are not present in all patients. Therefore, alternative methods to diagnose uterine prolapse when the cervix is not clearly visualized on TPUS would be valuable.\u003c/p\u003e \u003cp\u003eThe levator ani muscle (LAM) plays a key role in supporting the pelvic organs (\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). The levator plate angle (LPA) reflects the degree of inclination of the levator plate, and changes in the LPA with contraction and relaxation of the LAM correspond to the functional status of the LAM (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). The anorectal angle (ARA) is considered an important parameter for evaluating anorectal function, and the changes in ARA during maximal squeeze and Valsalva maneuvers are thought to reflect the functional state of the pelvic floor muscles (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Previous studies have shown that ultrasound and defecography provide comparable measurements of the ARA (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Therefore, we hypothesized that TPUS measurements of the LPA and ARA could provide diagnostic information for uterine prolapse.\u003c/p\u003e \u003cp\u003eBased on the hypothesis above, this study aims to investigate the relationship between LPA and ARA measured by TPUS in different states and the severity of uterine prolapse. We anticipate that these measurements will provide valuable diagnostic indicators for uterine prolapse diagnosis.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design\u003c/h2\u003e \u003cp\u003eThis prospective study consecutively enrolled patients who underwent POP-Q and TPUS examinations at the Second Affiliated Hospital of Fujian Medical University for symptoms of lower urinary tract or pelvic floor dysfunction from August 2022 to December 2023. The flowchart of the study population enrollment is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e. This study was approved by the institutional review boards of the Second Affiliated Hospital of Fujian Medical University (No. 2021\u0026ndash;012). All subjects volunteered to participate and provided signed informed consent.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe POP-Q examinations were performed by experienced gynecologists (with \u0026ge;\u0026thinsp;2 years of ICS POP-Q examination experience), who were blinded to the participants' clinical information and ultrasound findings. The exclusion criteria were: (a) women aged\u0026thinsp;\u0026lt;\u0026thinsp;18 years; (b) poor image quality that did not allow for complete visualization of the levator plate and pubic bone; (c) inability to perform a valid Valsalva maneuver or presence of levator muscle coactivation during the Valsalva maneuver (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e); (d) history of large pelvic masses or pelvic-related surgeries; (e) pelvic floor dysfunction syndrome (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e); (f) Women with predominant anterior or posterior vaginal wall prolapse. For women with multi-compartment prolapse, if uterine prolapse was at the same POP-Q stage as anterior or posterior vaginal wall prolapse, they were included. A total of 130 women were finally included in the study, with 45 in the POP-Q\u0026thinsp;=\u0026thinsp;0 group, 45 in the POP-Q\u0026thinsp;=\u0026thinsp;1 group, and 40 in the POP-Q\u0026thinsp;\u0026ge;\u0026thinsp;2 group.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eTransperineal Ultrasound Assessment\u003c/h2\u003e \u003cp\u003eTransperineal ultrasound was performed using the GE Voluson E8 or E10 ultrasound device (GE Healthcare, Zipf, Austria) with 4-8MHz curved array volume transducer and with an acquisition angle of 85\u0026deg;. Before the examination, participants were instructed to empty their bladder and bowel as much as possible and were trained to sustain a Valsalva maneuver for at least 6 seconds. The participants were examined in the lithotomy position, with the perineum fully exposed. The probe was placed on the median sagittal plane, and the images were adjusted until the inferior margin of the symphysis pubis, cervix, anorectal junction, and the posterior levator ani muscle were clearly visualized (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Each participant maintained the Valsalva maneuver for at least 6 seconds, and no levator muscle coactivation was observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Measurements included the LPA and ARA at rest (rLPA and rARA) and at maximal Valsalva maneuver (vLPA and vARA). The change in LPA from rest to maximal Valsalva (ΔLPA) was calculated as vLPA minus rLPA, and the change in ARA from rest to maximal Valsalva (ΔARA) was calculated as vARA minus rARA. The LPA was defined as the angle between the horizontal line at the inferior margin of the symphysis pubis and the line connecting the inferior margin of the symphysis pubis and the anorectal junction (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). The LPA was considered negative when the anorectal junction was located above the inferior margin of the symphysis pubis and positive when it was located below. The ARA is defined as the angle between the posterior wall of the rectum and the central axis of the anal canal (\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTwo ultrasound physicians with identical qualifications repeated the measurements on the same ultrasound device. They were blinded to the clinical data and POP-Q stage of the participants before the examination. An ultrasound physician who did not participate in the study assisted in recording and obscuring the measurement values displayed on the screen, so the examining physicians were unaware of their own measurement values. Examiner A first performed the examination and measurements, followed by Examiner B 0.5 hours later, and then Examiner A again 0.5 hours later. The intraclass correlation coefficient (ICC) was used to evaluate the intra- and inter-observer reliability of the LPA and ARA measurements.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eStatistical analysis of the data was conducted using SPSS version 26.0 software for Windows (SPSS Inc, Chicago, IL, USA). Normality was assessed using the Shapiro-Wilk test. Data with normal distribution are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (\u003cem\u003ex\u0026thinsp;\u0026plusmn;\u0026thinsp;s\u003c/em\u003e), and differences were analyzed using one-way analysis of variance. Non-normally distributed data are presented as median (interquartile range), and differences were analyzed using the Kruskal-Wallis \u003cem\u003eH\u003c/em\u003e test. Bonferroni correction was applied for pairwise comparisons. Categorical data were presented as n (\u003cem\u003e%\u003c/em\u003e) and compared using the chi-square test. The reliability of intra- and inter-observer measurements was assessed using the ICC with a 95% confidence interval. Correlation analysis was performed using Spearman's method, with \u003cem\u003e|r|\u003c/em\u003e \u0026ge; 0.8 indicating a high correlation, 0.5 \u0026le; \u003cem\u003e|r|\u003c/em\u003e \u0026lt; 0.8 indicating a moderate correlation, 0.3 \u0026le; \u003cem\u003e|r|\u003c/em\u003e \u0026lt; 0.5 indicating a low correlation, and 0 \u0026lt; \u003cem\u003e|r|\u003c/em\u003e \u0026lt; 0.3 indicating a weak correlation. Receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was calculated. The DeLong test was used to compare the diagnostic performance, and the Youden index was used to determine the optimal cutoff value. For all analyses, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eRepeatability analysis of LPA and ARA measurements by transperineal ultrasound\u003c/h2\u003e \u003cp\u003eThe intra- and inter-observer reproducibility of LPA and ARA measurements by the same physician and different physicians with the same qualifications under different conditions are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The results showed that the measurements of LPA and ARA under different conditions by the same physician or different physicians with the same qualifications had good consistency and repeatability, with ICC values all exceeding 0.83.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eIntra-observer and inter-observer reproducibility of ultrasonographic measurements\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMeasure\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIntra-observer reproducibility (n\u0026thinsp;=\u0026thinsp;20)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eInter-observer reproducibility (n\u0026thinsp;=\u0026thinsp;20)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eICC (95%CI)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.987(0.968\u0026ndash;0.995)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.962(0.907\u0026ndash;0.985)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.962(0.907\u0026ndash;0.985)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.952(0.882\u0026ndash;0.981)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆LPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.977(0.943\u0026ndash;0.991)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.964(0.910\u0026ndash;0.986)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erARA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.886(0.735\u0026ndash;0.953)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.868(0.696\u0026ndash;0.945)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evARA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.858(0.676\u0026ndash;0.941)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.837(0.634\u0026ndash;0.932)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆ARA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.953(0.882\u0026ndash;0.982)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.934(0.833\u0026ndash;0.974)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eICC, intraclass correlation coefficient; CI, confidence interval; rLPA, levator plate angle at rest; vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rARA, anorectal angle at rest; vARA, anorectal angle during maximum Valsalva maneuver; ∆ARA, change in anorectal angle from rest to maximal Valsalva.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eComparison of clinical data and transperineal ultrasound measurement data\u003c/h2\u003e \u003cp\u003eThe baseline demographic characteristics and transperineal ultrasound measurements of the study population are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. There were statistically significant differences among the three groups in terms of average age, parity, history of vaginal delivery, menopausal status, and urinary incontinence symptoms (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). As the severity of uterine prolapse increased, vLPA gradually decreased (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Compared to POP-Q stage\u0026thinsp;=\u0026thinsp;0, rLPA decreased in the POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, and both the POP-Q stage\u0026thinsp;=\u0026thinsp;1 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 showed a decrease in ΔLPA (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e. With the increasing severity of uterine prolapse, vARA and ΔARA initially decreased and then increased (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05); however, there was no statistically significant difference in rARA among different degrees of uterine prolapse (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.151), as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Spearman correlation analysis revealed a moderate negative correlation between the degree of uterine prolapse and vLPA (\u003cem\u003er\u003c/em\u003e = -0.621, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and a low negative correlation between the degree of uterine prolapse and rLPA, ΔLPA (\u003cem\u003er\u003c/em\u003e = -0.305, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001; \u003cem\u003er\u003c/em\u003e = -0.420, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical data and transperineal ultrasound measurements of the study population\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGeneral Clinical and Ultrasonic Data\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePOP-Q stage\u0026thinsp;=\u0026thinsp;0\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePOP-Q stage\u0026thinsp;=\u0026thinsp;1\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePOP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;45)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eF/H/X\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.11\u0026thinsp;\u0026plusmn;\u0026thinsp;6.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.44\u0026thinsp;\u0026plusmn;\u0026thinsp;9.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e45.68\u0026thinsp;\u0026plusmn;\u0026thinsp;10.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParity (times)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.82\u0026thinsp;\u0026plusmn;\u0026thinsp;0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.011\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVaginal delivery history\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19(42.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41(91.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e37(92.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e38.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMenopausal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(17.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22(48.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19(47.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e11.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.003\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUrinary incontinence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9(20.0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23(51.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e17(42.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e9.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.007\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erLPA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.47\u0026thinsp;\u0026plusmn;\u0026thinsp;7.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.14\u0026thinsp;\u0026plusmn;\u0026thinsp;6.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.10\u0026thinsp;\u0026plusmn;\u0026thinsp;6.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e0.002\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evLPA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.70(8.57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-9.19(10.96)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-16.08(12.45)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e50.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆LPA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-23.41\u0026thinsp;\u0026plusmn;\u0026thinsp;9.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31.04\u0026thinsp;\u0026plusmn;\u0026thinsp;9.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-34.17\u0026thinsp;\u0026plusmn;\u0026thinsp;10.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e14.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erARA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e109.51(9.31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e111.73(9.79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e109.48(8.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.151\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evARA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e112.30(6.79)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e103.33(10.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e121.39(15.57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e45.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆ARA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.17(3.20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-8.31(10.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.52(6.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e74.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e\u0026lt;\u0026thinsp;0.001\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eData are presented as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations or median (interquartile range) or frequencies and percentages in parentheses. rLPA, levator plate angle at rest; vLPA, levator plate angle during maximum Valsalva maneuver; ∆LPA, change in levator plate from rest to maximal Valsalva; rARA, anorectal angle at rest; vARA, anorectal angle during maximum Valsalva maneuver; ∆ARA, change in anorectal angle from rest to maximal Valsalva.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eDiagnostic efficacy of rLPA, vLPA, and ΔLPA for the severity of uterine prolapse\u003c/h2\u003e \u003cp\u003eThe diagnostic efficacy of transperineal ultrasound parameters in assessing the severity of uterine prolapse is presented in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. DeLong's test showed that vLPA had the best efficacy in diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1, (vLPA vs rLPA, \u003cem\u003eZ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.679, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05; vLPA vs ΔLPA, \u003cem\u003eZ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.070, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, (vLPA vs rLPA, \u003cem\u003eZ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.282, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.023; vLPA vs ΔLPA, \u003cem\u003eZ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.178, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.002). The optimal cutoff value of vLPA for diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 was \u0026minus;\u0026thinsp;2.29\u0026deg;, with a sensitivity of 0.87 and a specificity of 0.82. For POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, the optimal cutoff value of vLPA was \u0026minus;\u0026thinsp;6.97\u0026deg;, with a sensitivity of 0.85 and a specificity of 0.68. Figures\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e6\u003c/span\u003e and \u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003e display the ROC curves for rLPA, vLPA, and ΔLPA in diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAccuracy of parameters measured by transperineal ultrasound in diagnosing the severity of uterine prolapse\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCutoff value(\u0026deg;)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAUC(95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSensitivity(95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSpecificity(95% CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLR +\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eLR -\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePOP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-2.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.86(0.78\u0026ndash;0.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.87(0.78\u0026ndash;0.93)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.82(0.68\u0026ndash;0.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e4.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆LPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-26.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.75(0.67\u0026ndash;0.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.79(0.69\u0026ndash;0.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.62(0.47\u0026ndash;0.76)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e27.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.65(0.57\u0026ndash;0.74)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.84(0.74\u0026ndash;0.91)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.49(0.34\u0026ndash;0.64)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePOP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003evLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-6.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.80(0.72\u0026ndash;0.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.85(0.70\u0026ndash;0.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.68(0.57\u0026ndash;0.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e∆LPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-34.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.69(0.60\u0026ndash;0.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.55(0.39\u0026ndash;0.71)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.79(0.69\u0026ndash;0.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003erLPA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.67(0.58\u0026ndash;0.75)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.78(0.62\u0026ndash;0.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.52(0.41\u0026ndash;0.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePOP-Q, pelvic organ prolapse quantification; AUC, area under the receiver operating characteristic curve; CI, confidence interval; LR, likelihood ratio.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe results of this study demonstrate that the intra- and inter-observer reliability of transperineal ultrasound measurements of LPA and ARA in the resting and Valsalva states were excellent, with ICC values all exceeding 0.83, consistent with previous studies (\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). This indicates that the assessment of LPA and ARA is a feasible approach for evaluating the severity of uterine prolapse.\u003c/p\u003e \u003cp\u003eOur study found that as the severity of uterine prolapse increased, the values of vLPA, rLPA, and ΔLPA gradually decreased. Spearman correlation analysis revealed a moderate negative correlation between the degree of uterine prolapse and vLPA, and a weak negative correlation between the degree of uterine prolapse and rLPA, ΔLPA. The LAM is a critical muscle group supporting pelvic floor organs, and its contraction and relaxation lead to the up-and-down movement of the levator plate, resulting in changes in the LPA angle. The stronger the contraction ability of the LAM, the greater the changes in the angle (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In their study of pelvic floor disorders, Jeong et al (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e) found that an increase in the scores for LAM deficiency was associated with changes in the static pelvic shape at rest, with the levator plate moving downward towards the perineum, leading to a decrease in LPA. Additionally, there was a moderate negative correlation between levator ani muscle deficiency scores and LPA at rest (\u003cem\u003er\u003c/em\u003e = -0.528, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Hoyte et al (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e) found that the vLPA was decreased in the prolapse group compared to the non-prolapse group. Qiu et al (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e)also reported that ΔLPA decreased with increasing POP-Q scores for posterior vaginal wall prolapse using dynamic MRI analysis. Our study supports these previous findings. Additionally, we established the optimal cutoff values for the diagnosis of uterine prolapse in POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 by transperineal ultrasound measurement of LPA in different states. Among these, the efficacy of vLPA was the highest. When the vLPA value was less than \u0026minus;\u0026thinsp;2.29\u0026deg;, the sensitivity and specificity for diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 were 0.87 and 0.82. Similarly, when the vLPA value was less than \u0026minus;\u0026thinsp;6.97\u0026deg;, the sensitivity and specificity for diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 were 0.85 and 0.68. These results indicate that vLPA can be effectively used to assess the severity of uterine prolapse. Currently, in the assessment of uterine prolapse using transperineal ultrasound, the distance from the horizontal line located at the lower edge of the pubic symphysis to the horizontal line at the anterior edge of the cervix is commonly used. However, identifying the position of the cervix is often challenging. In contrast, the measurement of the levator plate angle is less susceptible to interference from other factors and appears clearer in transperineal ultrasound examinations.\u003c/p\u003e \u003cp\u003eInterestingly, we found that in patients with POP-Q stage\u0026thinsp;=\u0026thinsp;1, both vARA and ΔARA decreased compared to those POP-Q stage\u0026thinsp;=\u0026thinsp;0 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, whereas in patients with POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, ARA increased compared to POP-Q stage\u0026thinsp;=\u0026thinsp;0. Anatomically, the LAM wraps around the rectoanal junction from the posterior aspect and provides cranial elevation of the rectoanal junction. Disruption of the LAM leads to increased ARA, as the normal posterior rectal contour cannot be maintained without the proper insertion of the LAM (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). This results in an increase in ARA during Valsalva maneuver (\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e). In patients with POP-Q stage\u0026thinsp;=\u0026thinsp;1, the expansion of the levator ani muscle's hiatus during the Valsalva maneuver is more significant compared to those without prolapse, theoretically resulting in a larger ARA, but in our research, this was not the case. The reasons behind these results may be as follows: During the Valsalva maneuver in patients with POP-Q stage\u0026thinsp;=\u0026thinsp;1, the uterus may not exhibit significant descent. Due to the weakened uterine fascia and ligaments, the uterus is prone to posterior downward movement, pressing the rectum toward the sacrum, resulting in a decrease in ARA (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). Additionally, in patients with uterine prolapse accompanied by bladder prolapse, since the main prolapsed component is the uterus, the degree of descent of the bladder is also limited and tends to move posteriorly. Although the uterus is in between, it may still exert pressure on the rectum, causing a decrease in ARA. However, in patients with POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, the uterus primarily descends downward or even protrudes externally. At this stage, apart from the more pronounced dilation of the levator ani muscle hiatus, there is also compression of the rectovaginal septum by the prolapsed uterus, resulting in an increase in ARA (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003eC). Therefore, we believe that vARA and ΔARA may provide some reference value in the assessment of uterine prolapse.\u003c/p\u003e \u003cp\u003eThis study excluded women with predominant anterior or posterior compartment prolapse and those with levator ani muscle coactivation or pelvic floor dysfunction, thereby avoiding the confounding effects of these factors. However, there are limitations to this study. It is a single-center study with a small sample size, and it did not include questionnaire surveys or defecography examinations for all patients to assess bowel function. Therefore, it is unclear whether there are differences in bowel control among the three groups of patients.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eTransperineal ultrasound measurement of LPA is an effective method for evaluating uterine prolapse. Specifically, LPA assessment during Valsalva maneuver demonstrates the best diagnostic performance and could be incorporated as a new parameter in the transperineal ultrasound evaluation. ARA exhibits variations corresponding to different stages of uterine prolapse, and can be used as a supplementary reference in the assessment of uterine prolapse.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003ePOP\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePelvic organ prolapse\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eICS POP-Q\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInternational Continence Society Pelvic Organ Prolapse Quantification system\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eLAM\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003elevator ani muscle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eTPUS\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTransperineal ultrasound\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eLPA\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLevator plate angle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eARA\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnorectal angle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eICC\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIntraclass correlation coefficient\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eROC\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eReceiver operating characteristic\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eAUC\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eArea under the curve\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eParticipants in this study were fully informed about the study\u0026rsquo;s aims and protocol. Written informed consent was obtained from all participants. Ethical approval for this prospective data collection study was obtained from the Institutional Review Board of the Second Affiliated Hospital of Fujian Medical University (No. 2021 - 012).\u0026nbsp;All procedures were in accordance with ethical standards and the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConsent for publication:\u003c/em\u003e\u003c/strong\u003e Not Applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAvailability of data and materials:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eThe data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to their containing information that could compromise the privacy of research participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCompeting interests:\u003c/em\u003e\u003c/strong\u003e The authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFunding:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eThis work was supported by the Fujian Provincial Health Commission science and technology plan project (2022CXB010)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAuthors\u0026apos; contributions:\u0026nbsp;\u003c/em\u003e\u003c/strong\u003eSZ.H. and GR.L. were responsible for the project design and manuscript revision; JF.D., SL.L. and SJ.Z. are responsible for data collation and statistics; JF.D., JW.L. and W.X. are responsible for manuscript writing; All authors reviewed the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRaju R, Linder BJ. Evaluation and Management of Pelvic Organ Prolapse. Mayo Clinic Proceedings. 2021;96(12):3122-9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShek KL, Dietz HP. Assessment of pelvic organ prolapse: a review. Ultrasound Obstet Gynecol. 2016;48(6):681\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMadhu C, Swift S, Moloney-Geany S, Drake MJ. How to use the Pelvic Organ Prolapse Quantification (POP-Q) system? Neurourol Urodyn. 2018;37(S6):S39\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDietz HP. Ultrasound in the assessment of pelvic organ prolapse. Best Pract Res Clin Obstet Gynaecol. 2019;54:12\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDietz HP, Haylen BT, Broome J. Ultrasound in the quantification of female pelvic organ prolapse. Ultrasound Obstet Gynecol. 2001;18(5):511\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTan L, Shek KL, Atan IK, Rojas RG, Dietz HP. The repeatability of sonographic measures of functional pelvic floor anatomy. Int Urogynecol J. 2015;26(11):1667\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDietz HP, Rojas RG, Shek KL. Postprocessing of pelvic floor ultrasound data: how repeatable is it? Aust N Z J Obstet Gynaecol. 2014;54(6):553\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSiafarikas F, Staer-Jensen J, Braekken IH, Bo K, Engh ME. Learning process for performing and analyzing 3D/4D transperineal ultrasound imaging and interobserver reliability study. Ultrasound Obstet Gynecol. 2013;41(3):312\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTurel Fatakia F, Subramaniam N, Bienkiewicz J, Friedman T, Dietz HP. How repeatable is assessment of external anal sphincter trauma by exoanal 4D ultrasound? Ultrasound Obstet Gynecol. 2019;53(6):836\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDietz HP. Pelvic floor ultrasound: a review. Am J Obstet Gynecol. 2010;202(4):321\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAzpiroz F, Fernandez-Fraga X, Merletti R, Enck P. The puborectalis muscle. Neurogastroenterol Motil. 2005;17(Suppl 1):68\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlomquist JL, Carroll M, Munoz A, Handa VL. Pelvic floor muscle strength and the incidence of pelvic floor disorders after vaginal and cesarean delivery. Am J Obstet Gynecol. 2020;222(1):62. e1- e8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRodrigues AA Jr., Bassaly R, McCullough M, Terwilliger HL, Hart S, Downes K, et al. Levator ani subtended volume: a novel parameter to evaluate levator ani muscle laxity in pelvic organ prolapse. Am J Obstet Gynecol. 2012;206(3):e2441\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDavis SN, Morin M, Binik YM, Khalife S, Carrier S. Use of pelvic floor ultrasound to assess pelvic floor muscle function in Urological Chronic Pelvic Pain Syndrome in men. J Sex Med. 2011;8(11):3173\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaizada V, Mittal RK. Pelvic floor anatomy and applied physiology. Gastroenterol Clin North Am. 2008;37(3):493\u0026ndash;509. vii.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePutz C, Alt CD, Wagner B, Gantz S, Gerner HJ, Weidner N, et al. MR defecography detects pelvic floor dysfunction in participants with chronic complete spinal cord injury. Spinal Cord. 2020;58(2):203\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao YB, Yin HQ, Wang HJ, Liang HT, Wang B, Wang C. Is the transperineal ultrasonography approach effective for the diagnosis of rectocele? Gastroenterol Rep. 2021;9(5):461\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOrno AK, Dietz HP. Levator co-activation is a significant confounder of pelvic organ descent on Valsalva maneuver. Ultrasound Obstet Gynecol. 2007;30(3):346\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi M, Jiang T, Peng P, Yang X. MR Defecography in Assessing Functional Defecation Disorder: Diagnostic Value of the Defecation Phase in Detection of Dyssynergic Defecation and Pelvic Floor Prolapse in Females. Digestion. 2019;100(2):109\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNam G, Song JY, Lee SR. A New Angle Measurement in Translabial Ultrasound as an Adjunct for the Diagnosis of Pelvic Organ Prolapse. Diagnostics (Basel Switzerland). 2022;12(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoos JE, Willmann JK, Weishaupt D, Lachat M, Marincek B, Hilfiker PR. Thoracic aorta: motion artifact reduction with retrospective and prospective electrocardiography-assisted multi-detector row CT. Radiology. 2002;222(1):271\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChoi JS, Wexner SD, Nam YS, Mavrantonis C, Salum MR, Yamaguchi T, et al. Intraobserver and interobserver measurements of the anorectal angle and perineal descent in defecography. Dis Colon Rectum. 2000;43(8):1121\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJorge JM, Wexner SD, Marchetti F, Rosato GO, Sullivan ML, Jagelman DG. How reliable are currently available methods of measuring the anorectal angle? Dis Colon Rectum. 1992;35(4):332\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRostaminia G, White DE, Quiroz LH, Shobeiri SA. Levator plate descent correlates with levator ani muscle deficiency. Neurourol Urodyn. 2015;34(1):55\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLone F, Sultan AH, Stankiewicz A, Thakar R. Interobserver agreement of multicompartment ultrasound in the assessment of pelvic floor anatomy. Br J Radiol. 2016;89(1059):20150704.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarc\u0026iacute;a-Mejido JA, Garc\u0026iacute;a Pombo S, Fern\u0026aacute;ndez-Conde C, Fern\u0026aacute;ndez-Palac\u0026iacute;n A, Borrero C, Sainz-Bueno JA. Reproducibility of the anorectal angle with transperineal ultrasound. Quant imaging Med Surg. 2023;13(3):1664\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJeong HY, Park DH, Lee JK. Levator plate descent angle in pelvic floor disorders. Tech Coloproctol. 2021;25(9):1011\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoyte L, Schierlitz L, Zou K, Flesh G, Fielding JR. Two- and 3-dimensional MRI comparison of levator ani structure, volume, and integrity in women with stress incontinence and prolapse. Am J Obstet Gynecol. 2001;185(1):11\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQiu Z, Song Y. A Hypothesis Generating the Mechanical Systems Underlying Posterior Vaginal Prolapse Based on Observed Displacements by Dynamic Magnetic Resonance Imaging. Female Pelvic Med Reconstr Surg. 2020;26(9):585\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarc\u0026iacute;a-Mejido JA, Garc\u0026iacute;a-Pombo S, Fern\u0026aacute;ndez-Conde C, Borrero C, Fern\u0026aacute;ndez-Palac\u0026iacute;n A, Sainz-Bueno JA. The Role of Transperineal Ultrasound for the Assessment of the Anorectal Angle and Its Relationship with Levator Ani Muscle Avulsion. Tomography. 2022;8(3):1270\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCyr MP, Kruger J, Wong V, Dumoulin C, Girard I, Morin M. Pelvic floor morphometry and function in women with and without puborectalis avulsion in the early postpartum period. Am J Obstet Gynecol. 2017;216(3):274. e1- e8.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Uterine prolapse, ultrasound examination, levator plate angle, anorectal angle","lastPublishedDoi":"10.21203/rs.3.rs-4535033/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4535033/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eConfirming the patient's cervical position using transperineal ultrasound is not an easy task. This study aimed to employ transperineal ultrasound to measure the levator plate angle (LPA) and anorectal angle (ARA) in patients with varying degrees of uterine prolapse and to explore their efficacy in assessing uterine prolapse.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis prospective study consecutively enrolled 130 female patients who underwent examinations for lower urinary tract or pelvic floor dysfunction symptoms at the Second Affiliated Hospital of Fujian Medical University from August 2022 to December 2023. Participants were divided into three groups based on the Pelvic Organ Prolapse Quantification (POP-Q) system: POP-Q\u0026thinsp;=\u0026thinsp;0 (n\u0026thinsp;=\u0026thinsp;45), POP-Q\u0026thinsp;=\u0026thinsp;1 (n\u0026thinsp;=\u0026thinsp;45), and POP-Q\u0026thinsp;\u0026ge;\u0026thinsp;2 (n\u0026thinsp;=\u0026thinsp;40). Transperineal ultrasound was used to measure the LPA and ARA at rest (rLPA and rARA) and during maximum Valsalva maneuver (vLPA and vARA). Changes in LPA and ARA from rest to maximal Valsalva (ΔLPA and ΔARA) were calculated. The differences in these ultrasound parameters among the three groups were compared. The area under the curve (AUC) was calculated to assess the diagnostic performance.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eWith increasing severity of uterine prolapse, vLPA decreased progressively, while vARA and ΔARA initially decreased and then increased (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Compared with the POP-Q stage\u0026thinsp;=\u0026thinsp;0 group, rLPA was reduced in the POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 group, and ΔLPA was reduced in the POP-Q stage\u0026thinsp;=\u0026thinsp;1 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 groups (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The optimal cutoff values for diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 were 27.01\u0026deg; for rLPA, -2.29\u0026deg; for vLPA, and \u0026minus;\u0026thinsp;26.11\u0026deg; for ΔLPA, with corresponding AUCs of 0.65, 0.86, and 0.75. For diagnosing POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2, the optimal cutoff values were 24.11\u0026deg; for rLPA, -6.97\u0026deg; for vLPA, and \u0026minus;\u0026thinsp;34.57\u0026deg; for ΔLPA, with corresponding AUCs of 0.67, 0.80, and 0.69. DeLong's test indicated that vLPA had the highest efficacy in diagnosing both POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;1 and POP-Q stage\u0026thinsp;\u0026ge;\u0026thinsp;2 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eTransperineal ultrasound measurement of the LPA and ARA is a simple and effective method for assessing uterine prolapse.\u003c/p\u003e","manuscriptTitle":"Transperineal ultrasound measurement of the levator plate angle and anorectal angle is a useful method for evaluating uterine prolapse : a prospective cohort study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-27 18:54:09","doi":"10.21203/rs.3.rs-4535033/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1a246546-655d-48e6-8f3e-ffa2d5d4ed51","owner":[],"postedDate":"June 27th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-05-08T10:53:35+00:00","versionOfRecord":[],"versionCreatedAt":"2024-06-27 18:54:09","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4535033","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4535033","identity":"rs-4535033","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}