Pelvic floor dysfunction (PFD) is an umbrella term used to describe pelvic function disorders including pelvic organ prolapse (POP), urinary incontinence, faecal incontinence and descending perineal syndrome (DPS). Many different modalities have been used to diagnose the posterior compartment pelvic floor disorders including defecography, ultrasound and MRI. Static 2D trans-perineal ultrasound has been used for many years in diagnosing patients with pelvic floor dysfunction. Dynamic trans-perineal ultrasound has been suggested by Beer-Gabel et al., (2002) to assess the interaction of the pelvic viscera and its relationship to pelvic floor musculature in patients with evacuatory disorders and pelvic floor dysfunction (1). 3D/4D ultrasound is being used with promising result compared to MRI as it is increasingly accessible, cheaper, dynamic, and utilises a non-invasive technique. (2) We aim to review the role of the 3D /4D trans-perineal ultrasound in diagnosis of posterior compartment disorders and its reliability as a good bedside screening tool for colorectal surgeons.

A comprehensive review of PubMed/Medline, Scopus, and Web of Science was conducted for studies using the following  ‘Pelvic floor sonography’; ‘Pelvic floor 3D’; ‘Perineal ultrasound’; ‘Introital ultrasound’; ‘Pelvic floor’; ‘3D’ and ‘4D’; between the period 2000 to 2023. Preliminary results identified 104 published articles. Articles which discussed the role of transperineal/translabial (introital) 3D ultrasound in diagnosis of posterior compartment disorders were included. Anterior compartment disorder diagnosed with 3D Transperineal US in addition to isolated 2d or endoanal 3D approach or endovaginal 3D studies to assess posterior compartment disorders were excluded

The total number of studies included in this review was 48 (including ;12 review articles, 1 systematic review and metanalysis). Twenty four (68.5 %) of the remaining studies discussed biometrics and changes that affect the levator ani muscle (LAM) and with gynaecological specialty authors. The total number of participants included was 5699.

Majority of studies used trans-perineal or introital non-invasive 3D ultrasonography with curved array transducer to perform dynamic 2D ultrasound followed by 3D/4D imaging as first reported by Dietz et al., (2004), whilst only 3 studies used the endovaginal probe for translabial ultrasound.
Detection of levator Muscle defects and hiatal biometry measurements on transperineal 3D ultrasound showed moderate to good agreement in comparison to findings on MRI. When compared to defection proctography, 3D/4D transperineal ultrasound was better tolerated and showed very promising results in detection of rectocele, anismus and enterocele; yielding information on middle and anterior compartment disorders in the same setting. Additionally, 3D/4D transperineal ultrasound has the advantage that it can be learnt in a short period of time and could be easily incorporated into pelvic floor examinations.

Being useful, non-invasive with good outcomes, 3D trans-perineal ultrasound can be considered as a primary screening tool that can used more by colorectal surgeons as a bed side tool. However, This review does not discuss other methods that can be used for pelvic floor disorder diagnosis. Most of the studies are observational retrospective studies. More randomised control trials with large number of participants are recommended to compare accuracy of different probes and to compare this technique with other isolated or integrated ultrasound techniques and other methods of pelvic floor disorder diagnostic tools

Beer-Gabel, M., Teshler, M., Barzilai, N., Lurie, Y., Malnick, S., Bass, D., & Zbar, A. (2002). Dynamic transperineal ultrasound in the diagnosis of pelvic floor disorders: pilot study. Diseases of the colon & rectum, 45, 239-248.
Dietz, H. P. (2004). Ultrasound imaging of the pelvic floor. Part II: three-dimensional or volume imaging. Ultrasound in Obstetrics and Gynecology: The Official Journal of the International Society of Ultrasound in Obstetrics and Gynecology, 23(6), 615-625.
Notten, K. J., Vergeldt, T. F., van Kuijk, S. M., Weemhoff, M., & Roovers, J. P. W. (2017). Diagnostic accuracy and clinical implications of translabial ultrasound for the assessment of levator ani defects and levator ani biometry in women with pelvic organ prolapse: a systematic review. Urogynecology, 23(6), 420-428.

Continence 7S1 (2023) 100900
DOI: 10.1016/j.cont.2023.100900