In vivo assessment of the elastic properties of women's pelvic floor during pregnancy using shear wave elastography: design and protocol of the ELASTOPELV study

What is known about changes in pelvic floor muscle strength and tone in women during the childbirth pathway? A scoping review

INTRODUCTION

This scoping review aims to comprehensively explore the existing research on the changes in pelvic floor function that occur throughout the childbirth pathway (antenatal, intrapartum, and postnatal period). Furthermore, it seeks to identify new opportunities and directions for future research in this field. In particular, this review focuses on investigating pelvic floor muscle strength and tone in women during the childbirth pathway.

METHODS

The following databases were investigated from their inception: PubMed, OVID, Medline, ScienceDirect, The Cochrane Central Library, Scopus, Web of Science, PEDro, Scholar Google, Embase, and CINHAIL. Literature research was carried out from March to October 2022. Records identified through database searching were imported to Covidence. According to Arksey and O'Malley's five-stage scoping review framework, researchers screen titles and abstracts for eligibility and exclude records that do not meet the inclusion criteria.

RESULTS

A total of 40 studies were included in the data extraction phase. These articles underwent a review, with a specific emphasis on examining the tone, strength, and distensibility of the pelvic floor throughout the childbirth pathway. Among the selected studies, 22 investigated pelvic floor strength, 7 the distensibility, and 3 articles the tone.

CONCLUSIONS

This review identified both areas of agreement and disagreement across all three themes examined, with a particular emphasis on labor and the postpartum period. Notably, the review unveiled a significant scarcity of data concerning the tone of pelvic floor muscles throughout the childbirth pathway. Further studies to investigate the relationship between midwifery care and pelvic floor outcomes are required to improve clinical practice.

In vivo measurement of the elastic properties of pelvic floor muscles in pregnancy using shear wave elastography

OBJECTIVE

We aimed to investigate changes in the elastic properties of levator ani muscle (LAM) and external anal sphincter (EAS) during pregnancy using shear wave elastography (SWE). Our secondary objective was to examine the association between the elastic properties of pelvic floor muscles (PFM) and perineal tears at childbirth.

METHODS

This was a prospective monocentric study, including nulliparous women. Three visits were planned (14-18, 24-28, and 34-38 weeks) with a SWE assessment of the LAM and EAS at rest and during Valsalva maneuver. Then, we collected data about the delivery's characteristics. Assessments were performed using an Aixplorer V12® device (SL 18-5 linear probe) using a transperineal approach, reporting the shear modulus in kPa. We looked for changes in PFM's elastic properties during pregnancy using one-way ANOVA for repeated measures. We compared the mean shear modulus in late pregnancy for each muscle and condition between women with an intact perineum at delivery and those with a perineal tear using Student's t test.

RESULTS

Forty-seven women were considered. Forty-five women had vaginal delivery of which 38 (84.4%) had perineal tears. We did not report any significant changes in the elastic properties of PFM during pregnancy. Women with an intact perineum at delivery had a stiffer EAS at Valsalva maneuver in late pregnancy (27.0 kPa vs. 18.2 kPa; p < 0.005).

CONCLUSIONS

There were no significant changes in the elastic properties of the PFM in pregnancy. Stiffer EAS in late pregnancy appears to be associated with a lower incidence of perineal tears.

Review of shear wave elastography in placental function evaluations

Background: Ultrasound is key to evaluating placental function. However, traditional ultrasound examinations cannot evaluate the changes in the biomechanical properties of the placenta in vivo. As a non-invasive technique, shear wave elastography (SWE) can be used analyze the physiological and biomechanical properties of the placenta. Moreover, it can evaluate the pathological changes in early placental insufficiency in a more direct and sensitive manner.Objective: This study aimed to systematically introduce SWE in placental function evaluations.Materials and methods: The terms 'placenta', 'ultrasound', and 'elastography' were searched on Pubmed, Embase, and CNKI databases (Apr 2023); this review was limited to results including placental sonoelastography.Results: Twenty-six studies satisfied the inclusion criteria and were included in this review. Herein, we introduce the basic principle of SWE, analyze the factors affecting placental measurements, and summarize the prospects of clinical applications of SWE in the field of obstetrical diseases.Conclusion: The SWE technology demonstrates excellent clinical application value and research prospects in obstetrics, particularly in placental function evaluation, owing to its objective and repeatable quantitative operation.

The Correlation between Transperineal Shear-Wave Elastography and Transabdominal Ultrasound When Assessing Pelvic Floor Function in Nulliparous Women

Pelvic floor muscles (PFMs) play a crucial role in maintaining pelvic organ support and continence. However, pelvic floor dysfunction (PFD), often resulting from insufficient PFM control, poses a substantial global health challenge for women. This study aims to explore the relationship between levator ani muscle elasticity when assessed through transperineal shear-wave elastography (SWE) and bladder base displacement, quantified using transabdominal ultrasonography (TAUS), as a means to comprehensively evaluate PFM function. A total of 42 nulliparous women participated in this study. Participants received instructions on proper PFM contractions using Kegel exercises. Levator ani muscle elasticity was assessed both at rest and during contractions using transperineal SWE, while bladder base displacement was simultaneously measured through TAUS. Repeated measures demonstrated strong intraclass correlation coefficients of 0.906 at rest and 0.687 during contractions for levator ani muscle elasticity. The mean elasticity values were 24.7 ± 4.5 kPa at rest and 62.1 ± 10.4 kPa during contractions. Additionally, the mean bladder base displacement was 7.2 ± 2.5 mm, and the normalized bladder base displacement via body mass index was 0.3 ± 0.1 mm. Significantly, a moderate correlation was identified between the PFM function, represented by the difference in levator ani elasticity during contractions and resting, and bladder base displacement (r = 0.486, p = 0.001). These findings underscore the potential utility of transperineal SWE as a reliable and noninvasive method to assess levator ani muscle elasticity and, consequently, PFM function. In conclusion, this study sheds light on the interplay between PFM elasticity and bladder base displacement, offering insights into PFM function assessments. The observed correlation suggests the clinical relevance of SWE in providing valuable information for treatment planning in PFD. These findings contribute to a deeper understanding of PFM dynamics, ultimately aiding in the effective management of PFD among women.

In vivo assessment of the elastic properties of the external anal sphincter in term pregnant women using shear wave elastography

INTRODUCTION AND HYPOTHESIS

The objective was to assess the intraobserver intersession and interobserver intrasession reliability of shear wave elastography applied to the external anal sphincter in term pregnant women.

METHODS

This prospective study involved nulliparous pregnant women at 37 weeks or more with two visits (V1: one observer; V2 two observers) planned within a 12-h to 7-day interval. Measurements were performed using an Aixplorer V12® device with an SL 18-5 linear probe using a transperineal approach, allowing a measurement of the shear modulus (SM) in kPa. Measures were performed at rest, Valsalva maneuver, and maximal contraction. Reliability was assessed using the intraclass correlation coefficient (ICC). The study was approved by an ethics committee (ID RCB: 2020-A00764-65).

RESULTS

A total of 37 women were included. Intraobserver reliability was excellent at rest (ICC = 0.91 [0.84-0.95) and good during the Valsalva maneuver (ICC = 0.83 [0.72-0.90]) and contraction (ICC = 0.85 [0.75-0.91]). Interobserver reliability was good at rest (ICC = 0.79 [0.66-0.87]) and during Valsalva (ICC = 0.84 [0.73-0.90]), but moderate during contraction (ICC = 0.70 [0.53-0.82]).

CONCLUSIONS

Shear wave elastography is a reliable tool for assessing the elastic properties of the external anal sphincter in term pregnant women.

Evaluation of the clinical value of shear wave elastography for early detection and diagnosis of diabetic peripheral neuropathy: a controlled preliminary prospective clinical study

PURPOSE

This study aims to analyze the clinical application value of shear wave elastography (SWE) technique for early diagnosis of diabetic peripheral neuropathy (DPN).

METHODS

Diabetic patients hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Anhui Medical University from August 2021 to February 2022 were enrolled as DPN group (n=38) and non-DPN group (n=35) based on the neurophysiological examination results. 30 healthy subjects were recruited as the control group during the same period. Ultrasound examination of the tibial nerve and related laboratory tests were examined and collected for the total 103 study subjects. Statistical analysis of the collected data, and the receiver operating characteristic(ROC) curve for determination of the optimal cut-off values of mean stiffness of tibial nerve to detect DPN, with determination of area under curve (AUC), specificity, sensitivity, and Youden index.P value < 0.05 is considered statistically significant.

RESULTS

Gender, age and BMI differences among three groups were insignificant (P>0.05). The difference of serological indicators between DPN and non-DPN groups was also not found (P>0.05), whereas longer duration of diabetes was observed in DPN group as compared to non-DPN group. As to the ultra-sound relevant parameters, the cross-sectional area and elastic modulus of the tibial nerve in both lower extremities among these three groups were not significantly different (Oneway ANOVA analysis) although the differences were indeed observed if we compared DPN group exclusively with non-DPN group, or compared non-DPN group with healthy group, or compared DPN group with healthy group (t test). Additionally, the mean elasticity (Emean) cut-off value for the diagnosis of DPN was preferably taken as 67.55 kPa.

CONCLUSION

SWE has unique advantages in early detection and diagnosis of DPN, which deserve further research.

The impact of physical activity during pregnancy on labor and delivery

BACKGROUND

Physical activity in pregnancy is associated with decreased risks of adverse pregnancy outcomes such as gestational diabetes and preeclampsia. However, the relationship between the amount and type of physical activity during pregnancy and subsequent labor outcomes remains unclear.

OBJECTIVE

This study aimed to test the hypothesis that higher levels of physical activity across different lifestyle domains in pregnancy are associated with a shorter duration of labor.

STUDY DESIGN

This study is a secondary analysis of a prospective cohort study in which patients with singleton pregnancies without a major fetal anomaly were administered the Kaiser Physical Activity Survey in each trimester. The Kaiser Physical Activity Survey was designed specifically to quantify various types of physical activities in women and includes 4 summative indices-housework/caregiving, active living habits, sports, and occupation. The study included women at full-term gestations admitted for induction of labor or spontaneous labor. The primary outcome of this analysis was duration of the second stage of labor. Secondary outcomes were duration of the active stage, prolonged first and second stage, mode of delivery, rates of second-stage cesarean delivery, operative vaginal delivery, severe perineal lacerations, and postpartum hemorrhage. These outcomes were compared between patients with and without high physical activity levels, defined as overall Kaiser Physical Activity Survey score ≥75th percentile in the third trimester. Multivariable logistic regression was used to adjust for obesity and epidural use. In addition, a subgroup analysis of nulliparous patients was performed.

RESULTS

A total of 811 patients with complete Kaiser Physical Activity Survey data in the third trimester were included in this analysis. The median Kaiser Physical Activity Survey score was 9.5 (8.2-10.8). Of the 811 patients, 203 (25%) had higher levels of physical activity in pregnancy. There was no difference in the duration of the second stage of labor between patients with and without higher physical activity levels (1.29±2.94 vs 0.97±2.08 hours; P=.15). The duration of active labor was significantly shorter in patients with higher levels of physical activity (5.77±4.97 vs 7.43±6.29 hours; P=.01). Patients with higher physical activity levels were significantly less likely to have a prolonged first stage (9.8% vs 19.4%; P<.01; adjusted relative risk, 0.55; 95% confidence interval, 0.34-0.83). However, rates of prolonged second-stage cesarean delivery, operative vaginal deliveries, and perineal lacerations were similar between the 2 groups.

CONCLUSION

Patients who are more physically active during pregnancy have a shorter duration of active labor.

Transperineal ultrasound shear-wave elastography is a reliable tool for assessment of the elastic properties of the levator ani muscle in women

Our main objective was to assess the intraoperator intersession reproducibility of transperineal ultrasound Shear Wave Elastography (SWE) to measure the levator ani muscle (LAM) elastic properties. Secondary objective was to compare reproducibility when considering the mean of three consecutives measurements versus one. In this prospective study involving non-pregnant nulliparous women, two visits were planned, with a measurement of the shear modulus (SM) on the right LAM at rest, during Valsalva maneuver and maximal contraction. Assessments were done with a transperineal approach, using an AIXPLORER device with a linear SL 18–5 (5-18 MHz) probe. For each condition, 3 consecutive measures were performed at each visit. The mean of the three measures, then the first one, were considered for the reproducibility by calculating intraclass correlation coefficient (ICC), and coefficient of variation (CV). Twenty women were included. Reproducibility was excellent when considering the mean of the 3 measures at rest (ICC = 0.90; CV = 15.7%) and Valsalva maneuver (ICC = 0.94; CV = 10.6%), or the first of the three measures at rest (ICC = 0.87; CV = 18.6%) and Valsalva maneuver (ICC = 0.84; CV = 19.9%). Reproducibility was fair for measurement during contraction. Transperineal ultrasound SWE is a reliable tool to investigate LAM elastic properties at rest and during Valsalva maneuver.

Advancing frontiers in rheumatic and musculoskeletal imaging

In recent years, technological improvements allowed imaging modalities to become increasingly essential in achieving early and precise diagnoses in the field of rheumatic and musculoskeletal diseases (RMDs). To date, imaging examinations are routinely used in all steps of diagnostic and therapeutic care pathways of patients affected by RMDs. The articles published in this Article Collection clearly show the efforts of researchers to find innovative applications of musculoskeletal imaging in clinical practice and to face the crucial challenges that remain in the interpretation and quality control of images. Highly performing diagnostic technologies are currently available to early diagnose and accurately monitor several musculoskeletal disorders, but also to guide personalized interventional therapeutic procedures tailored to the individual patients in the emerging process of precision medicine. Among these new modalities, some are particularly promising and thereby subject to several lines of research in RMDs, including SPECT-CT and dual-energy CT, MRI sequences, high and ultra-high frequency ultrasound with effective tools like shear wave elastography.