In some clinics daily used cube pessaries are offered to the women with pelvic organ prolapse (POP) as first line treatment, in most of the centers - as second or third line. Some specialists advocate that cube pessary can activate pelvic floor muscles  (1). It was not investigated if avulsion of puborectalis muscle can have negative influence on effective cube pessary insertion. Palpation and ultrasound was used to investigate pelvic floor in many aspects (2, 3). 
In our opinion optimal for pelvic floor evaluation is placing the transducer externally. In many studies 2D and 4D abdominal probes were used for transperineal examinations, in some - introital transvaginal pelvic floor ultrasound was used. There are no study comparing those methods.
We hypothesized that cube pessary could reduce hiatal dimensions at rest. We hoped that cube pessary would improve Kegel’s exercises, and during Valsalva maneuver would have protective effect on pelvic floor through minimizing enlargement of the hiatal dimensions. We expected that puborectalis total avulsion could minimize positive influence on pelvic floor in comparison to women without total avulsion.
The aim of the study was to evaluate during ultrasound examination the influence of cube pessary on female’s pelvic floor at rest and if cube pessary will change the effectiveness of Kegel’s exercises or Valsalva maneuver. The additional aim was to find out if puborectalis avulsion will correct the influence of cube pessary on pelvic floor.

Between 1st April 2016 and 28th February 2018 247 female patients entered urogynecologic center to treat symptomatic POP. 10 were excluded (unsuccessful fitting, incomplete results). This is a retrospective study of data obtained from 237 women, 25- 85 years old (average - 61). All patients had a standardized not validated interview, a clinical assessment using the ICS POP-Q, along with a 2D introital pelvic floor ultrasound (transvaginal probe - PFS-TV) (2) and 2D/4D transperineal ultrasound (abdominal probe - PFU-TA) (3) using GE Kretz Voluson 730 Pro. Bladder neck mobility was evaluated during maximal Kegel's and on maximal Valsalva lasted min. 5 sec in PFS-TV and PFU-TA - value HI (longitudinal axis) and value DI (transverse axis), (Fig. 1), (2, 3). Hiatal dimensions (area - AH, circumference CH, longitudinal diameter LH) were measured in the plane of minimal hiatal dimension (PFU-TA). Longitudinal distance between symphysis pubis and puborectalis muscle was measured in 2D mode (PFU-TA) – SL. Levator trauma was identified by tomographic ultrasound (TUI in PFU-TA) (3). 
One experienced specialist using set of pessaries, fitted perforated cube pessaries with button and knot from number 0 to 5 (Dr Arabin, Germany, Fig. 2). The goal of the therapy was that the patient herself will insert a pessary in the morning and take it out in the evening. 
Another specialist was experienced in pelvic floor ultrasound, both PFU-TA and PFS-TV.

All patients had symptoms of POP, 30.8% - stress urinary incontinence, 39.2% - overactive bladder, 16.5% - voiding difficulty. 
On examination a cystocele stage 2+ was found in 86.9%, significant central compartment prolapse in 54.9%, and a rectocele stage 2+ - in 43%. In 89% we detected any form of prolapse of stage 2 or higher. 
Mean vaginal parity was 2.0 (range, 0- 5), and 81% were vaginally parous. A vacuum or Forceps was reported by 2.1%, a hysterectomy by 8%. BMI was 27 (range, 18-53). 
The percentage of fitted cube pessaries was as follows: size 0 - 6.3%, 1 – 20.0%, 2 – 33.0%, 3 - 26.7%, 4 - 10.4%, 5 - 3.6%. POP-Q stage had no influence on fitted cube pessary size. There were statistically significant differences on hiatal dimensions between patients with different cube pessary size (0-5) – bigger for bigger pessary (in cm2 AH: 20.75, 20.54, 23.67, 27.38, 30.49, 33.87, in cm CH: 17.11, 17.04, 18.32, 19.69, 20.65, 21.85, in cm LH: 6.25, 6.29, 6.73, 7.22, 7.56, 8.05). 
After inserting cube pessary at rest D value (PFU-TA and PFS-TV) was smaller than before insertion (1.68cm vs. 2.1cm, p<0.0004 and 1.04cm vs. 1.38cm, p<0.0004). The rest measurements were not different.
The differences in HI (PFU-TA and PFS-TV), SL, AH, CH and LH during Kegel’s exercises performed without pessary and with pessary inserted were not statistically significant. DI in PFS-TV in patients with cube pessary had lower value (0.30cm vs. 0.46, p<0.007), but in PFU-TA differences were not statistically significant (0.15cm vs. 0.27, p<0.12).
During Valsalva maneuver the following diameters were smaller in women with cube pessary inserted comparing to pessary taken out: value HI PFS-TV (0.8cm vs. 1.45cm, p<0.000000), value HI PFU-TA (0.92cm vs. 1.61cm, p<0.000000), AH (-3.9cm2 vs. -6.62cm2, p<0.000000), CH (-1.21cm vs. -2.12cm, p<0.000000), LH (-0.38cm vs. -0.6cm, p<0.000014), SL (-0.15cm vs. -0,25cm, p<0.016). The difference in DI value in PFS-TV was statistically significant (-0.29cm vs. -0.44, p<0.04), while in PFU-TA did not reach statistical significance (-0.17cm vs. -0.28, p<0.08)
During Kegel’s exercises a higher degree of hiatus decreasing size was observed in women without total puborectalis avulsion in comparison to patients with avulsion: LH (1.03cm vs. 0.72cm, p<0.00052), AH (4.66cm vs. 3.22cm, p<0.000588), CH (2,18cm vs. 1,43cm, p<0.0006). 
During Valsalva maneuver differences were not statistically significant, however in patients without total puborectalis avulsion hiatal dimensions were smaller.
There were no statistically significant differences in value HI (PFU-TA and PFS-TV) between patients with and without avulsion during Kegel's exercises and Valsalva maneuver.

We confirmed that POP-Q stage had no influence on chosen cube pessary size. Hiatal dimensions (AH, CH, LH) correlated with cube pessary size which was successfully fitted.
At rest, inserted cube pessary moved bladder neck to symphysis pubis - lower DI values after pessary insertion in comparison to measurements without pessary. The rest measurements including hiatal dimensions did not change after pessary insertion.
We did not find statistically significant influence of cube pessary insertion on efficiency of Kegel's exercises. The difference in DI value measured at rest and Kegel’s during PFS-TV was smaller in women with cube pessary inserted. In women with pessary at rest, bladder neck was closer to the symphysis pubis and this could be the reason for this difference. 
During Valsalva maneuver, cube pessary showed protective effect on pelvic floor through statistically significant lower hiatal dimensions and bladder neck mobility in comparison to measurements without inserted cube pessary. 
Women with pessary inserted without total puborectalis avulsion performed Kegel's exercises more efficiently than women with avulsion. We did not find statistically significant differences in protective effect of cube pessary between patients with total avulsion and without avulsion.
There were no statistically significant differences between patients with and without avulsion in bladder neck mobility during Kegel's exercises and Valsalva maneuver.

Fitted cube pessary sizes depended on hiatal dimensions. POP-Q stages had no influence on cube pessary size. 
At rest inserted cube pessary moved bladder neck to symphysis pubis. 
Cube pessary insertion did not have influence on pelvic floor during Kegel’s exercises, but could have protective effect during Valsalva maneuver. 
Cube pessary improved effectiveness of Kegel’s exercises better in women without total puborectalis avulsion in comparison to patients with avulsion. Cube pessary had similar protective effect on pelvic floor in women with and without avulsion during Valsalva maneuver.


Fig. 1. PFS-TV - evaluation of bladder neck position: HI and DI (S-symphysis)

Fig. 2. Perforated cube pessary

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