New Technique for Pelvic Floor Measurement - Transperineal Dynamic Ultrasound Measurement Method to Detection and Quantification of Rectocele, Cystocele, Enterocele and Perineal Descensus

The aim is to develop a unique and reliable sonographic method for the assessment and quantification of all pelvic floor changes from the group of obstructive defecation disorders. This method applied to all affected patients regardless of their age, size, weight etc., should deliver reliable and unique data.

The pelvic floor is a complex area, exhibiting diverse pathologies [1,2]. Within the so-called emptying disorders can be found the obstructive defecation syndromes. The causes of this type of syndrome include the deterioration of the structures holding the pelvic organs physiologically in their positions [3,4]. Previous investigation methods include MR, classic defecography, uro-gynecological, proctological examinations, scores etc., [5-9].

The diagnosis of each faculty differs fundamentally from the others, and even within the same pathological area there are different ideas about diagnostic methods and treatments. The results are classified with the Pelvic Organ Prolapse Quantification (POP-Q), as well as classified into different levels [6,10]. This is a rational approach, but has the disadvantage that only the gynecological pathologies are considered. The front compartment (urologic) is occasionally considered, but the rear compartment (proctologic) is practically never considered. POP-Q considered only the excess of the descent of the uterus, the bladder is not directly, the descent of the rear compartment not sufficiently assessed [10]. Therapy proposals often do not involve combined pathological changes, which occur mostly on the pelvic floor [11]. The resulting therapy does not therefore address the complexity of the condition.

We realized, over time, that isolated changes in the pelvic floor rarely occur even when a global and standard examination was deemed necessary [12,13]. Accurate knowledge of all anatomical and physiological changes is essential for an optimal and personalized treatment strategy [11].

In many studies the examination position of the pelvic floor is seen as controversial. There are numerous works in which the supine or even the left lateral examination position is chosen. The guidelines for uro-gynecology justify the horizontal examination position, with its improved practicality for the examiner, although this is controversial. Some investigations reject the supine examination position, because it is not physiologically and gravity is disregarded, which in turn distorts the results [9,14-18].

This controversy could be eliminated by performing the examination in a unit that includes both positions. To obtain reliable examination results, first the supine position and then the sitting physiological position should be selected [17]. Both sets of results should be checked against not only what revealed the pathologies, but should also include the influence of gravity acting on the patient (and the pelvic floor) during the examination.

Pelvic floor examination using ultrasound has not until now been sufficiently established. Although a good correlation of ultrasound and proctologic measurements has been secured the lack of the ultrasound marker and examiner dependency are the most critical drawbacks [19,20]. The entire pelvic floor can be simply and reliably examined non-invasively by the transperineal pelvic floor 3D sonography assessment [19-24]. All three compartments are dynamically assessed at the same time, increasing the validity [17,25,26]. The study of a single compartment, however, seems to be insufficient for a firm diagnosis [27].

Due to the lack of standardized processes and sizes, the relevance of pelvic floor ultrasound treatment has not been sufficiently considered, although it is a direct method, simulating almost unchanged all the sequences of a defecation [28]. The necessity of a reproducible method delivering accurate, ubiquitous and comparable results at any time of the assessment is clear.

Despite the high level of availability and the increasing dissemination of transperineal sonography, relevant measuring points at the transperineal image of the pelvic floor are still missing (the pubis is the one bony structure that retains the position during movement, such as Valsalva) [29,30]. This however leaves too much scope for interpretation. It leaves the assessment examiner dependent and does not allow any clear quantification of the organ descend, even if it is very clearly visible. The previous measuring points at the transperineal representation were Bladder Symphysis Distance (BSD), anorectal angle, alpha, beta, gamma angle, hiatus size etc., [8,30-33].

These readings attempt to establish some order in the sonographic view of the pelvic floor. The classic angles and distances can change (such as the valsalva maneuver, squeeze, etc.), and they are measured. They have however no unique expressiveness and do not describe any quantification of the pathological change. The corresponding image must be interpreted freely.

The observation of the change of the absolute values (bladder symphysis distance etc.) in reference to pubic symphysis is not sufficient for the evaluation of the expression of the pelvic organ descent. The relative changes in the organ position in relation to the normal state, which means the during valsalva provoked percentage change in the position to the baseline, seems much more important. The bench mark values are determined in the rest/supine position. In this way comparability for all issues is attained, regardless of the present pathology. The measuring method is lean on the existing Pelvic Organ Prolapse Quantification (POPQ) classification.

There are seven important factors for this measuring method:

• Reproducibility
• Can be applied to all patients (regardless of age, weight, height, pre-existing conditions, treatment etc.)
• Can be performed either pre- or post-procedure
• The values obtained are unique, fully reproducible, ubiquitous and comparable
• The determination of the value measured does not depend on the examiner (i.e., there is no room for misinterpretation)
• All three compartments can be simultaneously assessed; the isolated evaluation of several pathologies is blocked, and this which improves diagnostic safety
• Examination time is not significantly extended - the entire assessment requires approximately 15-20 minutes

The measuring points of the pelvic floor (transperineal view)

The method of measurement is based on the determination of eight points (measured in both the supine and the sitting positions, including the Valsalva). The change of one position to another and the value of this change is documented. The percentage change in the location of these points (organs) then leads to the diagnosis.
The measuring points must be clearly definable, and should be easily tracked by any movement of the pelvic floor (valsalva or squeeze, etc.)
The following marks have been selected (Figure 1):

1. Symphysis pubis 
2. Interior of ostium urethrae
3. External ostium urethrae
4. Cervix
5. Posterior rectal wall - height of symphysis pubis 
6. Anterior rectal wall - height of cervix
7. Anterior rectal wall - height of symphysis pubis
8. Anterior rectal wall - height of internal ostium urethrae

Figure 1: Clearly defined measuring points at the transperineal image of the pelvic floor.

1-Symphysis pubis; 2-Internal ostium urethrae; 3-External ostium urethrae; 4/C-cervix; 5-Posterior rectal wall - height symphysis pubis; 6-Anterior rectal wall - height cervix; 7-Anterior rectal wall - height symphysis pubis; 8-Anterior rectal wall - height internal ostium urethrae; B-Bladder; VG – Vagina; C-Cervix (height vesical roof, arrow), SP-Symphysis pubis; R-rectum

Measurement of individual distances
The following distances were measured at rest and then at the Valsalva, and received the following designations:

Front compartment (Figure 2):

1. The symphysis pubis - inside the Urethraostium (bladder symphyis distance) - 1
2. The inner ostium urethrae – the outer Ostium urethrae - 1a
3. The symphysis pubis - the bladder roof (regardless of the bladder filling) or (the cervix - if visible - is preferable) - 2
4. The bladder roof/cervix - the internal ostium urethrae - 2a

These measured values are used as a template for the other measurements and are transferred into the middle and posterior compartments (Table 1).

Compartments	Measurement name	Proceed
Front compartment
	1	Measurement
	1a	Measurement
	2	Measurement
	2a	Measurement
Middle compartment
	3	Adoption of value of 1
	3a	Measurement
	4	Adoption of value 2
	4a	Measurement
Dorsal compartment
	5	adoption value of 1
	5a	Measurement
	6	Adoption of value 2
	6a	Measurement

Table 1: Summary of the approach to the measurement of the pelvic floor.

The values 1, 1a, 2, and 2a are determined. Output values are 1 and 2 and are the basis for the other measurements, which are then transferred to 3, 4, 5 and 6. This is based on a virtual value as a ‘template’ for measurement of the rest. The change is then measured in the Valsalva (sitting position).

Middle compartment (Figure 2):

5. The outer introitus vaginae (at symphysis pubis) - value 1 is adopted - 3
6. From there the distance to the outer introitus vaginae - 3a
7. The outer introitus median (at symphysis pubis) - value 2 is adopted - 4
8. From there the distance to the outer introitus measured - 4a

Dorsal compartment (Figure 2):

9. The posterior rectal wall (hight symphysis pubis) - value 1 is adopted - 5
10. The longest distance to the anterior rectal wall (the height above the external sphincter) measured - 5a
11. The posterior rectal wall (the height of the symphysis pubis) - the value of 2 is adopted - 6
12. The longest distance to the anterior rectal wall is measured from that point (the height above external the sphincter) - 6a


Figure 2: The distances shown in the pelvic floor measurement first in rest (supine position) then Valsalva (in sitting position).

Following distances are determined: 1-Symphysis pubis - inner urethra ostium (BSD); 1a-Inner urethra ostium - outer ostium urethrae; 2-Symphysis pubis - bladder roof (regardless of the bladder filling) or (height cervix - if it is visible - preferable); 2a-Bladder roof/cervix - internal ostium urethrae. The values 1 and 2 as a template for all further measurements will be taken in 3,4,5 and 6, while the values 3a, 4a, 5a, 6a must be measured in rest and Valsalva.

The measurements for the determination of Enterocele (Figure 3):

13. The anterior rectal wall - the height of the cervix (bladder roof) - d
14. The anterior rectal wall - the interior of the ostium urethrae - e
15. The anterior rectal wall - the height of the symphysis pubis - f


Figure 3: Detection of Enterocele - the defined distances d, e and f must be determined in rest (supine examination position) and during Valsalva (seated examination position).

This value d is the distance between - anterior rectal wall - height cervix (bladder roof). Distance e - between the anterior rectal wall - internal ostium urethrae, and distance f - between the anterior rectal wall and symphysis pubis. The enlargements of the distances to more than 50% show the presence of an Enterocele.

The values obtained in the supine position (without the Valsalva) are entered in a corresponding table. Afterwards the patient in the sitting position is prompted to execute the Valsalva maneuver, and the same points are measured and entered in the same table.

The values are then compared. The difference is first represented as an absolute number and also as a percentage variation. To increase the accuracy of the figures of the respective compartments (for example, 2 and 2a, or 4 and 4a), they are combined to form an arithmetic mean. This improves the accuracy and corrects any measurement outliers.

The values for the Enterocele in the tables are entered in the next step. Here, the differences in the percentage variation of the absolute numbers are also converted.

The investigation results show the percentage change in the position of clearly defined measuring points in all pelvic floor organs (bladder, uterus, rectum) due to the Valsalva in the sitting position (Figure 4). The evaluation is based on the previous pelvic organ prolapse classification.

This means in detail: A change in the position of, for example, the bladder (determined by a change in the position of the internal and external urethra, etc.). Less than 30% to the initial value means a bladder descensus of Iº.

A change in the position of the bladder by more than 30% but less than 60% of the initial value means a bladder descensus of IIº.

A change of more than 90% to the initial value means a bladder descensus of IIIº.

The approach in evaluation of the middle and the dorsal compartment is here the same (Figures 4 and 5).

Figure 4: The change in the position of the organs in the Valsalva maneuver (examination sitting position) can be quantified by the renewed determination of the measured values.

The individual compartments are represented at the same time, so that both individual and combined pathologies are detected. Not the absolute values, but the percentage changes of the measured values are critical for the diagnosis. The evaluation is standardized through clearly defined limits (discrepancy less than 30% - grade I, grade II, 30-60% more than 90% discrepancy III).

Figure 5: The position change of the organs during the Valsalva maneuver (sitting position) shows an isolated Zystocele IIIº, as well as descensus vaginae IIº.

The percentage increase in the measured values for the bladder is more than 90% grade IIIº, and for the middle compartment between 30% and 60% - level II. The rear compartment is not affected in this example.

For anterior compartment measurements it is important to measure the distance (1a, 2a) between the internal and external ostium of the urethra to determine the maximum bladder expansion (Figure 5).

The determination of vaginal descenus (with measurements of 3a and 4a) should include the distal visible vaginal tissue. Here identification can be difficult, due to compression of the soft tissue by the transducer (Figures 4 and 5).

The measurement of the extension of the rectocele (5a, 6a) has the endpoint with regard to the rectum anterior wall just above the front edge of the Musculus Sphincter Ani Externus (MSAE). Here the farthest distance should be chosen. During the Valsalva this point is detached according to the shape of the rectocele (Figure 4).

The shape of the descensus perinei (levels I, II and III) can be calculated from the previous values.

The evaluation of the Enterocele shows a peculiarity. Changing all three output values determined by more than 50% secures an Enterocele IIIº. (The anterior rectal wall - the height of the cervix/bladder roof - value is d) if the change is more than 50% - an Enterocele Iº. A change of the two upper output values (the anterior rectal wall - the height of the cervix/bladder roof value is d and the anterior rectal wall - ostium urethrae - e) is more than 50% - an Enterocele IIº. An Enterocele is excluded in all other cases/configurations (Figure 3).