Diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion.

OBJECTIVE: To estimate the diagnostic test accuracy of magnetic resonance imaging (MRI) and pelvic floor ultrasound for levator ani muscle (LAM) avulsion in a general parous population, with view to establishing if ultrasound could substitute for MRI to diagnose LAM avulsion. METHODS: This was a cross-sectional study of 135 women 4 years after their first delivery. Signs and symptoms of pelvic floor dysfunction were assessed using validated methods. All women underwent four-dimensional transperineal ultrasound (TPUS), three-dimensional endovaginal ultrasound (EVUS) and MRI. Images were acquired at rest, on pelvic floor muscle contraction (PFMC) and on maximum Valsalva maneuver, and analyzed by two blinded observers. Predefined cut-off values were used to diagnose LAM avulsion. In the absence of a reference standard, latent class analysis (LCA) was used to establish diagnostic test characteristics for LAM avulsion as the primary outcome measure. Secondary outcomes were kappa (κ) agreement between imaging techniques, intraclass correlation coefficients (ICC) for hiatal measurements at rest, on PFMC and on maximum Valsalva maneuver, and the association of LAM avulsion with signs and symptoms of pelvic floor dysfunction. RESULTS: The prevalence of LAM avulsion was 23.0% for MRI, 11.1% for TPUS and 17.8% for EVUS. The prevalence of LAM avulsion using LCA was 15.7%. The sensitivity for LAM avulsion of TPUS (71% (95% CI, 50-90%)) and EVUS (91% (95% CI, 74-100%)) was lower than that of MRI (100% (95% CI, 84-100%)). The specificity of TPUS (100% (95% CI, 97-100%)) and EVUS (95% (95% CI, 91-99%)) was higher than that of MRI (91% (95% CI, 85-97%)). MRI and EVUS had high predictive values for the assessment of major LAM avulsion (positive predictive value (PPV), 95% and negative predictive value (NPV), 100%; PPV, 100% and NPV, 98%, respectively), while TPUS had high predictive values for minor LAM avulsion (PPV, 100% and NPV, 95%). Major LAM avulsion on MRI and EVUS was associated with anterior vaginal wall prolapse, which was not found for TPUS. The agreement in the diagnosis of LAM avulsion (κ, 0.69) and hiatal measurements (ICC, 0.60-0.81) was highest between MRI and EVUS. CONCLUSIONS: Pelvic floor ultrasound can be implemented as a triage test to assess parous women for LAM avulsion because of its high specificity. Ultrasound cannot substitute for MRI because of its lower sensitivity. The predictive ability of ultrasound is moderate for the presence, and very good for the absence, of LAM avulsion. A positive test should be confirmed by a different observer or imaging technique. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Natural history of levator ani muscle avulsion 4 years following childbirth.

OBJECTIVES: The primary aim was to evaluate prospectively the natural history of levator ani muscle (LAM) avulsion 4 years following first delivery and its correlation with signs and symptoms of pelvic floor dysfunction (PFD). The secondary aim was to investigate the effect of a second vaginal delivery on the incidence of LAM avulsion and PFD. METHODS: This was a prospective longitudinal study of nulliparous women recruited antenatally, who were assessed at 36 weeks' gestation and 3 months, 1 year and 4 years postpartum for signs and symptoms of PFD and presence of LAM avulsion. Pelvic floor muscle strength was assessed by digital palpation, and pelvic organ prolapse (POP) was assessed using the POP quantification (POP-Q) system. Validated questionnaires were used to evaluate urinary, bowel and sexual function and symptoms of POP. Transperineal ultrasound was performed to assess LAM integrity and hiatal biometry. Differences in signs and symptoms of PFD over time were evaluated using a linear mixed model, separately in women who had had one delivery and in those who had two or more deliveries during the study period. RESULTS: Of 269 women recruited, 147 (55%) attended the 4-year follow-up and were examined at a mean interval of 3.8 ± 0.4 years after their first delivery. Of these, 74 (50%) had a subsequent delivery. The prevalence of LAM avulsion 4 years after a first vaginal delivery was 13%, with no difference between women who had one and those who had two or more vaginal deliveries. Women with an intact LAM and one or more deliveries showed no change in signs and symptoms of PFD at 4 years compared with the previous assessments. Of women with one vaginal delivery who were diagnosed with LAM avulsion 3 months or 1 year postpartum, those in whom the LAM avulsion was no longer evident at 4 years (42%) showed worsening of POP-Q measurements, whereas those with persistent LAM avulsion (58%) showed significant worsening in pelvic floor muscle strength and hiatal area on ultrasound. After a second vaginal delivery, no new avulsions were diagnosed, however, previous LAM avulsion became more extensive in 44% of women and hiatal area increased in women with persistent LAM avulsion. CONCLUSIONS: The first vaginal delivery carries the greatest risk for LAM avulsion, with impact on signs of PFD 4 years later. A second vaginal delivery could result in deterioration of LAM avulsion, but no new avulsions were found. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Levator ani muscle morphology and function in women with obstetric anal sphincter injury.

OBJECTIVES: To estimate the prevalence of, and explore the risk factors for, levator ani muscle (LAM) injury in women with clinically diagnosed obstetric anal sphincter injury (OASI). The secondary aim was to assess the association between LAM injury and pelvic floor muscle contraction, anal incontinence (AI) and urinary incontinence (UI) in women with OASI. METHODS: This was a cross-sectional study of 250 women with OASI, recruited between 2013 and 2015 from a tertiary referral center at Croydon University Hospital, UK. AI symptoms were assessed using the modified St Mark's incontinence score and UI was assessed using the International Consultation on Incontinence modular Questionnaire for Urinary Incontinence - Short Form. All participants underwent three/four-dimensional transperineal ultrasound at rest and on maximum pelvic floor muscle contraction. Major LAM injury was defined as a unilateral or bilateral defect in all three central slices on tomographic ultrasound imaging. Muscle contraction was assessed using the modified Oxford scale (MOS) and measured on ultrasound as the proportional change in the anteroposterior (AP) levator hiatal diameter between rest and contraction. Multivariable logistic regression analysis was used to study risk factors for LAM injury. Differences in contraction and AI and UI symptoms between women with intact and those with injured LAM were studied using multivariable ANCOVA and the Mann-Whitney U-test. RESULTS: Of the 248 women with OASI for whom ultrasound volumes of adequate quality were available, 29.4% were found to have major LAM injury. The prevalence of LAM injury was 23.6% after normal vaginal delivery and 40.2% after operative vaginal delivery (adjusted odds ratio, 4.1 (95% CI, 1.4-11.9); P = 0.01). LAM injury was associated with weaker pelvic floor muscle contraction, with an adjusted mean difference for proportional change in AP diameter of 5.0 (95% CI, 3.0-6.9) and MOS of 0.6 (95% CI, 0.3-0.9) (P < 0.001 for both). AI and UI symptom scores were similar between women with intact and those with injured LAM. CONCLUSIONS: Operative vaginal delivery was a risk factor for LAM injury in women with OASI. LAM injury was associated with weaker pelvic floor muscle contraction. Special attention is recommended for women with OASI and LAM injury, as they are at high risk for future pelvic floor disorders. The benefits of implementation of an intensive, focused and structured pelvic floor rehabilitation program need to be evaluated in these women. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Morfología y función del músculo elevador del ano en mujeres con lesión obstétrica del esfínter anal OBJETIVOS: Estimar la prevalencia y explorar los factores de riesgo de lesión del músculo elevador del ano (MEA) en mujeres con lesión obstétrica del esfínter anal (LOEA) diagnosticada clínicamente. El objetivo secundario fue evaluar la asociación entre la lesión del MEA y la contracción muscular del suelo pélvico, la incontinencia anal (IA) y la incontinencia urinaria (IU) en mujeres con LOEA. MÉTODOS: Este fue un estudio transversal de 250 mujeres con LOEA, reclutadas entre 2013 y 2015 en un centro de referencia terciario del Hospital Universitario de Croydon en el Reino Unido. Los síntomas de IA se evaluaron mediante una modificación de la puntuación de incontinencia de San Marcos y los de la IU mediante el Formulario resumido del Cuestionario Modular de la Consulta Internacional sobre Incontinencia para la Incontinencia Urinaria. Todas las participantes se sometieron a una ecografía transperineal tridimensional en reposo y en máxima contracción de los músculos del suelo pélvico. Las lesiones importantes del MEA se definieron como un defecto unilateral o bilateral en los tres cortes centrales de la ecografía tomográfica. La contracción muscular se evaluó mediante la escala de Oxford modificada (EOM) y se midió en la ecografía como el cambio proporcional en el diámetro hiatal del elevador anteroposterior (AP) entre el reposo y la contracción. Se utilizó un análisis de regresión logística multivariable para estudiar los factores de riesgo de lesión del MEA. Se estudiaron las diferencias en la contracción y los síntomas de IA e IU entre las mujeres con el MEA intacto y las lesionadas, mediante un ANCOVA multivariable y la prueba U de Mann-Whitney. RESULTADOS: De las 248 mujeres con LOEA para las que se disponía de una cantidad de ecografías de calidad adecuada, se encontró que el 29,4% tenía una lesión importante del MEA. La prevalencia de lesiones del MEA fue del 23,6% después de un parto vaginal normal y del 40,2% después de un parto vaginal quirúrgico (razones de momios ajustadas, 4,1 (IC 95%: 1,4-11,9); P=0,01). Las lesiones del MEA se asociaron con una contracción muscular más débil del suelo pélvico, con una diferencia de medias ajustada para el cambio proporcional en el diámetro del AP de 5,0 (IC 95%: 3,0-6,9) y para la EOM de 0,6 (IC 95%: 0,3-0,9) (P<0,001 para ambos). Las puntuaciones de los síntomas de la IA y la IU fueron similares entre mujeres con el MEA intacto y mujeres con lesiones. CONCLUSIONES: El parto vaginal quirúrgico fue un factor de riesgo de lesión del MEA en mujeres con LOEA. La lesión del MEA se asoció con una contracción muscular más débil del suelo pélvico. Se recomienda prestar una atención especial a las mujeres con LOEA y con lesiones del MEA, ya que tienen un alto riesgo de futuros trastornos del suelo pélvico. Es necesario evaluar en estas mujeres los beneficios de la implementación de un programa intensivo, focalizado y estructurado de rehabilitación del suelo pélvico.

Does 4D transperineal ultrasound have additional value over 2D transperineal ultrasound for diagnosing posterior pelvic floor disorders in women with obstructed defecation syndrome?

OBJECTIVE: To establish the diagnostic test accuracy of two-dimensional (2D) and four-dimensional (4D) transperineal ultrasound (TPUS) for diagnosis of posterior pelvic floor disorders in women with obstructed defecation syndrome (ODS), in order to assess if 4D ultrasound imaging provides additional value. METHODS: This was a prospective cohort study of 121 consecutive women with ODS. Symptoms of ODS and pelvic organ prolapse on clinical examination were assessed using validated methods. All women underwent both 2D- and 4D-TPUS. Imaging analysis was performed by two blinded observers. Posterior pelvic floor disorders were dichotomized into presence or absence, according to predefined cut-off values. In the absence of a reference standard, a composite reference standard was created from a combination of results of evacuation proctography, magnetic resonance imaging and endovaginal ultrasound. Primary outcome measures were diagnostic test characteristics of 2D- and 4D-TPUS for rectocele, enterocele, intussusception and anismus. Secondary outcome measures were interobserver agreement, agreement between the two imaging techniques, and association of severity of ODS symptoms and degree of posterior vaginal wall prolapse with conditions observed on imaging. RESULTS: For diagnosis of all four posterior pelvic floor disorders, there was no difference in sensitivity or specificity between 2D- and 4D-TPUS (P = 0.131-1.000). Good agreement between 2D- and 4D-TPUS was found for diagnosis of rectocele (κ = 0.675) and moderate agreement for diagnoses of enterocele, intussusception and anismus (κ = 0.465-0.545). There was no difference in rectocele depth measurements between the techniques (19.9 mm for 2D vs 19.0 mm for 4D, P = 0.802). Interobserver agreement was comparable for both techniques, although 2D-TPUS had excellent interobserver agreement for diagnosis of enterocele and rectocele depth measurements, while this was only moderate and good, respectively, for 4D-TPUS. Diagnoses of rectocele and enterocele on both 2D- and 4D-TPUS were significantly associated with degree of posterior vaginal wall prolapse on clinical examination (odds ratio (OR) = 1.89-2.72). The conditions observed using either imaging technique were not associated with severity of ODS symptoms (OR = 0.82-1.13). CONCLUSIONS: There is no evidence of superiority of 4D ultrasound acquisition to dynamic 2D ultrasound acquisition for the diagnosis of posterior pelvic floor disorders. 2D- and 4D-TPUS could be used interchangeably to screen women with symptoms of ODS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.