Pelvic floor disorders in females are complex and encompass symptoms from all three compartments(1). The prevalence ranges from 1.9% to 46.5%(2–4). It is not possible to reliably understand the cause of pelvic floor symptoms based on history and examination alone and tailored investigations can be performed to guide treatment planning(5) such as integrated total pelvic floor ultrasound, defaecation proctogram, and defaecating MRI(6).

Transperineal ultrasound (TPUS) is a non-invasive test that allows the dynamic assessment of the entire pelvic floor with the detection and measurement of rectocele, enterocoele, cystocele, middle compartment descent(enterocoele, sigmoidocoele or uterine/vaginal prolapse) and perineal descent(7) and the assessment of pelvic floor function, such as the coordination of the pelvic floor on Valsalva maneuver.

Dynamic Transvaginal ultrasound (TVUS) enables the assessment of rectocele, enterocoele, intussusception, and the assessment of pelvic floor function on the Valsalva maneuver. It is an invasive test and may duplicate many of the negative findings already appreciated during transperineal scanning. 

We hypothesized that TPUS can be used as a screening tool, such that when it shows limited pathology, then, the invasive TVUS will not add any further information.

This is a single-institution study of patients with multi-compartment pelvic floor symptoms who underwent both transperineal and transvaginal ultrasound in a tertiary colorectal pelvic floor unit (PFU). PFU receives a mixture of both rural and urban referrals. 

Patients were identified from a prospectively maintained departmental database. Data was collected from the prospective database for age, ethnicity, and socioeconomic status. Consultant verified TPUS and TVUS reports were accessed through electronic patient records and data regarding anatomical and functional abnormalities was collected between March 2013 and October 2023.

A total of seven ethnicities were recorded, which were White British, White other, Black British, Black other, Asian, Mixed and Others. Socioeconomic status was proxied by the English Indices of Deprivation Measure 2019 (IMD)(8). The IMD scale ranges from 1 to 10. Patients were classified by the IMD score and divided into quintiles (1-5), by combining adjacent decile groups. The lowest quintile represented the most deprived while the highest quintile represented the least deprived.  

Data collected for anatomical abnormalities detected on TPUS included rectocele (bulge of the rectal wall over and beyond the perineal body such that rectum herniated into the vagina), enterocoele (hyperechoic mass descending from above the rectal ampulla into the vagina or rectovaginal space), middle compartment descent (Hyperechoic mass descending from the top into the vagina or rectovaginal space) and cystocele ( graded in relation to the vagina) while anatomical abnormalities detected on anterior TVUS included bladder neck descent (distance between the position of the bladder neck during squeezing up and on maximal descent). Data collected for anatomical abnormalities on posterior TVUS included rectocele (protrusion of the anterior rectal wall with impingement onto the perineal body on posterior transvaginal scanning), intussusception (innovative method was adopted as with the Oxford Radiological Grading System), and enterocoele (small bowel between the rectum and the endovaginal probe ). Functional parameters such as propulsion (poor propulsive effort was noted while bearing down) and coordination (poor coordination was the failure to open the anorectal angle during bearing down, rest: push ratio ≤1) were also collected for both TPUS and TVUS.

Data was analyzed after excluding missing values where a p-value <0.05 was considered significant.

A total of 1625 women underwent both TPUS and TVUS to investigate multi-compartment pelvic floor symptoms where the mean age was 52 +/- 14 years. 

Ethnicity
Unfortunately, 775 patients (47.7%)  did not have ethnicity recorded. The distribution was as follows: Asians (38,2.3%), Black British (22, 1.4), Black other (106, 6.5%), Mixed (24, 1.5%), Other (33, 2.0%), White British (529, 32.6%) and White other (98, 6%). 

Socio-economic status
There were 18 patients (1.1%) with data missing on IMD.  The distribution of patients according to IMD quintiles was as follows: IMD quintile 1 (251, 15.4%), IMD quintile 2 (451, 27.8%), IMD quintile 3 (356, 21.9%), IMD quintile 4 (282, 17.4%) and IMD quintile 5 (267, 16.4%). 

Anatomical abnormalities detected on TPUS and TVUS
Anatomical abnormalities observed on TPUS were 1134 rectocele, 183 enterocoeles, 175 middle compartment descent, and 742 cystoceles while 713 rectoceles, 104 enterocoeles, and 399 pathological intussusceptions (Grade III-V) were observed on posterior TVUS. Good bladder neck support was seen in 788(71.2%) on anterior TVUS. Of the total, 59.4% of rectocoeles and 40% of enterocoeles were detected on both TPUS and TVUS.


Functional abnormalities detected on TPUS and TVUS
Propulsion and co-ordination on TPUS
On TPUS, 328 patients (20.2%) had data missing for propulsion while 325 patients (20%) for coordination.  On TPUS, 952(73.4%) patients had good and 345(26.6%) had poor propulsion. On TPUS, 1018(78.3%) patients had good and 282(21.7%) had poor coordination. A total of 872(67.2%) patients had good propulsion and coordination while 202(15.6%) had poor propulsion and coordination on TPUS. 

Propulsion and co-ordination on TVUS
On TVUS, 322 patients (19.8%) had data missing for propulsion and coordination. On TVUS, 844(64.8%) patients had good and 459(35.2%) had poor propulsion. On TVUS, 900 (69.1%) patients had good and 403(30.69%) had poor coordination. A total of 808(62%) patients had good propulsion and coordination while 367(28.2%) had poor propulsion and coordination on TVUS.


Anatomical abnormalities detected on TPUS versus TVUS
Table 1 shows a comparison between findings detected on TPUS and TVUS

After excluding missing data, an enterocoele on TVUS was found in 1.9% when none were found on TPUS (NPV 98.1%), while a rectocele on TVUS was found in 7.9% when none on TPUS (NPV 92.1%).  Poor bladder neck support on TVUS was found in 8.8% when no cystocele was observed on TPUS (NPV 91.2%). Fewer anatomical abnormalities (rectocele, enterocoele, cystocele, intussusception, middle compartment descent, and poor bladder neck support) were detected on both TPUS and TVUS when patients had poor co-ordination and propulsion (p-value <0.001).


Table 2 shows a comparison of anatomical abnormalities detected when the propulsion and coordination were good versus poor (p-value < 0.001)

•	Recording ethnicity correctly may help understand if there exists any variability in the severity of symptoms, translating into variability in findings on ultrasound.

•	In comparison to TVUS, TPUS detected more rectocoele and enterocoele. This can be due to endo-probe which is used during TVUS preventing the full development of prolapsing structure, e.g.,  when the probe splints the rectocele, it causes it to flatten and prevents the herniation of the anorectal wall into the vagina. 

•	Observations can be under-reported if propulsion and coordination are poor.

•	Investigations are better performed after patients have undergone pelvic floor re-training so that anatomical abnormalities can be better appreciated with improved propulsion and coordination.

•	TPUS can be used as a visual biofeedback tool for re-training pelvic floor muscles and once the function (propulsion and coordination) has improved then a repeat TPUS and TVUS can be performed to assess anatomical abnormalities better.

If propulsion and coordination are adequate (which we understand is a subjective finding) then some pathology will be missed if only TPUS is performed. TPUS cannot provide a screening tool and patients should undergo both scans as a standard.

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Prevalence of pelvic floor dysfunction in women in Riyadh, Kingdom of Saudi Arabia: A cross-sectional study - Haifaa Malaekah, Haifaa Saud Al Medbel, Sameerah Al Mowallad, Zahra Al Asiri, Alhanouf Albadrani, Hussam Abdullah, 2022 [Internet]. [cited 2024 Mar 16]. Available from: https://journals.sagepub.com/doi/full/10.1177/17455065211072252