Ultrasound assessment of pelvic floor muscle contraction: reliability and development of an ultrasound-based contraction scale

OBJECTIVES

To determine intra- and interrater reliability and agreement for ultrasound measurements of pelvic floor muscle contraction and to assess the correlation between ultrasound and vaginal palpation. We also aimed to develop an ultrasound scale for assessment of pelvic floor muscle contraction.

METHODS

This was a cross-sectional study of 195 women scheduled for stress urinary incontinence (n = 65) or prolapse (n = 65) surgery or who were primigravid (n = 65). Pelvic floor muscle contraction was assessed by vaginal palpation using the Modified Oxford Scale (MOS) and by two- and three-dimensional (2D/3D) transperineal ultrasound. Proportional change in 2D and 3D levator hiatal anteroposterior (AP) diameter and 3D levator hiatal area between rest and contraction were used as measures of pelvic floor muscle contraction. One rater repeated all ultrasound measurements on stored volumes, which were used for intrarater reliability and agreement analysis, and three independent raters analyzed 60 ultrasound volumes for interrater reliability and agreement analysis. Reliability was assessed using the intraclass correlation coefficient (ICC) and agreement using Bland-Altman analysis. Tomographic ultrasound was used to identify women with major levator injury. Spearman's rank correlation coefficient (r_S ) was used to assess the correlation between ultrasound measurements of pelvic floor muscle contraction and MOS score. The proportion of women allocated to each category of muscle contraction (absent, weak, moderate or strong) by palpation was used to determine the cut-offs for the ultrasound scale.

RESULTS

Intrarater ICC was 0.81 (95% CI, 0.74-0.85) for proportional change in 2D levator hiatal AP diameter. Interrater ICC was 0.82 (95% CI, 0.72-0.89) for proportional change in 2D AP diameter, 0.80 (95% CI, 0.69-0.88) for proportional change in 3D AP diameter and 0.72 (95% CI, 0.56-0.83) for proportional change in hiatal area. The prevalence of major levator injury was 22.6%. The strength of correlation (r_S ) between ultrasound measurements and MOS score was 0.52 for 2D AP diameter, 0.62 for 3D AP diameter and 0.47 for hiatal area (P < 0.001 for all). On the ultrasound contraction scale, proportional change in 2D levator hiatal AP diameter of < 1% corresponds to absent, 2-14% to weak, 15-29% to normal and > 30% to strong contraction.

CONCLUSIONS

Ultrasound seems to be an objective and reliable method for evaluation of pelvic floor muscle contraction. Proportional change in 2D levator hiatal AP diameter had the highest ICC and moderate correlation with MOS score assessed by vaginal palpation, and we constructed an ultrasound scale for assessment of pelvic floor muscle contraction based on this measure. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Impact of levator muscle avulsions on Manchester procedure outcomes in pelvic organ prolapse surgery

INTRODUCTION

Levator ani muscle avulsions potentially increase recurrence after anterior colporrhaphies. We aimed at evaluating the impact of avulsions on anatomical and patient-reported outcomes 1 year after the Manchester procedure for primary anterior compartment pelvic organ prolapse.

MATERIAL AND METHODS

Prospective cohort study of 189 women undergoing the Manchester procedure between October 2014 and January 2017. Avulsions were diagnosed by transperineal ultrasound. Women with and without avulsions were compared for 1-year postoperative outcomes; Pelvic Organ Prolapse Quantification measurements, subjective satisfaction (1-worse to 4-cured), failure (new prolapse treatment), response to validated questionnaires on pelvic floor distress and sexual function, and a composite outcome (subjectively cured and optimal anterior compartment outcome (stage 0-I)). Optimal mid-compartment outcome was defined as cervix ≥5 cm above the hymen. Factors potentially associated with poor anatomical outcomes (anterior compartment stage ≥II) or pelvic floor distress were analyzed using regression analyses.

RESULTS

Fewer women with avulsions (present in 50.8%) obtained optimal mid-compartment outcomes (88.2% vs 77.1%; P = 0.05). The groups were otherwise similar in terms of mid-compartment reduction, anterior compartment results, failure rate, subjective satisfaction, pelvic floor/sexual symptoms, and combined optimal subjective and anatomical outcome. Only preoperative anterior compartment stage ≥III was associated with poor anatomical outcome (P < 0.01). A high preoperative symptom score was associated with a high postoperative symptom score (P < 0.001).

CONCLUSIONS

Although fewer women with avulsions obtained optimal mid-compartment results, avulsions had no impact on other anatomical or symptomatic outcomes 1 year after the Manchester procedure for primary anterior compartment prolapse.

Association of urinary and anal incontinence with measures of pelvic floor muscle contractility

OBJECTIVE

To assess the association between clinical and sonographic measures of pelvic floor muscle (PFM) function and symptoms of urinary and anal incontinence (AI).

METHODS

This was a retrospective study of women seen at a tertiary urogynecological unit. All women had undergone a standardized interview, clinical examination including Modified Oxford Scale (MOS) grading, urodynamic testing and four-dimensional translabial ultrasound (TLUS). Cranioventral shift of the bladder neck (BN) and reduction in the hiatal anteroposterior (AP) diameter were measured using ultrasound volumes acquired on maximal PFM contraction, blinded against all clinical data.

RESULTS

Data from 726 women with a mean age of 56 ± 13.7 (range, 18-88) years and a mean body mass index of 29 ± 6.1 (range, 17-55) kg/m(2) were analyzed. Stress (SI) and urge (UI) urinary incontinence were reported by 73% and 72%, respectively, and 13% had AI. Mean MOS grade was 2.4 ± 1.1 (range, 0-5). Mean cranioventral BN shift on TLUS was 7.1 ± 4.4 (range, 0.3-25.3) mm; mean reduction in AP hiatal diameter was 8.6 ± 4.8 (range, 0.3-31.3) mm. On univariate analysis, neither MOS nor TLUS measures were strongly associated with symptoms of urinary incontinence or AI; associations were non-significant except for BN displacement/SI (7.3 mm vs 6.5 mm; P = 0.028), BN displacement/UI (6.85 vs 7.75; P = 0.019), hiatal AP diameter/AI (9.6 mm vs 8.5 mm; P = 0.047) and MOS/SI (2.42 vs 2.19; P = 0.013).

CONCLUSIONS

In this large retrospective study we did not find any strong associations between sonographic or palpatory measures of PFM function and symptoms of urinary incontinence or AI. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

The association between different measures of pelvic floor muscle function and female pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

We aimed to compare palpatory and translabial ultrasound (TLUS) measurements of pelvic floor muscle (PFM) function with symptoms and signs of female pelvic organ prolapse (FPOP) to determine a possible association.

METHODS

We analysed data from 726 women with a mean age of 56 (SD 13.7, range 18-88) years, seen for symptoms of pelvic floor dysfunction between August 2011 and April 2013. The examination included a standardised interview and clinical assessment of FPOP with Pelvic Organ Prolapse Quantification (POP-Q) measurements, Modified Oxford Scale (MOS) grading and 4D TLUS.

RESULTS

Symptoms of prolapse were reported in 51.4% (373 out of 726) with a mean bother score of 5.8 (SD 2.91, range 0-10). A clinically significant POP (Incontinence Society [ICS]-POP-Q stage ≥ 2) in any compartment was diagnosed in 77.1%. Mean MOS was 2.4 (SD 1.1, range 0-5). Significant POP on TLUS was seen in 54.6% (389 out of 712). TLUS volumes at rest and on maximal PFM contraction were analysed on a desktop PC, to assess the degree of bladder neck (BN) cranioventral shift and levator antero-posterior (AP) diameter reduction, blinded against other data. Mean cranioventral BN shift was 7.11 (SD 4.36, range 0.32-25.32) mm and mean levator AP diameter reduction was 8.6 (SD 4.8, range 0.3-31.3) mm. MOS was strongly associated with subjective and objective POP (P ≤ 0.001), whereas this was not true for TLUS measurements of tissue displacement.

CONCLUSION

The MOS seems to be a more valid measure of PFM function than sonographically determined BN displacement or reduction of hiatal AP diameter observed on PFM contraction.