Evaluation of pessary placement on the anatomy of the pelvic organs in patients with pelvic organ prolapse using imaging techniques

Pelvic organ prolapse (POP) is a common problem in middle aged women. In the
Netherlands, the prevalence of symptomatic POP in women between 45-85 years is
11.4%. A pessary is a relatively inexpensive treatment option that reduces POP
symptoms. However, in 56% of the cases complications occur and the success
rates after 1 year are only between 50 and 73%. Furthermore, researchers and
clinicians have different thoughts about the position of a pessary inside the
body and research into risk factors associated with unsuccessful pessary
fitting shows conflicting results. Therefore, it is needed to investigate the
position of a pessary and the influence of a pessary on the pelvic organs to
gain more insight in factors associated with successful pessary fitting.
Imaging techniques can be used to evaluate the position of a pessary. Magnetic
resonance imaging (MRI) is an imaging technique in which three dimensional
imaging of multiple compartments is possible. The additional value of the use
of upright MRI is that pessary fitting can be evaluated in the position in
which the extent of prolapse is significantly larger than in supine position.
There is a large amount of unknowns considering the effect of a pessary on the
pelvic organs. Insight in these unknowns may be useful to optimize the pessary
treatment and reduce the complication rate and the amount of unsuccessful
fittings.

This protocol describes a framework that will be used to create multiple
studies, which are based on the secondary objectives. The outcomes of the
studies together will provide more insight in the primary objective.

Primary Objective:
Investigate the effect of a pessary on the position and shape of the pelvic
organs in patients with POP, when pessary fitting is successful (i.e. the
patient continues the use of a pessary for >= 3 months).

Secondary Objectives:
- Evaluate which parameters are associated with a change of the position and
shape of the pelvic organs due to insertion of a pessary in successful pessary
fitting.
- Evaluate the position and orientation of the pessary in successful pessary
fitting.
- Evaluate if the parameters measured using upright MRI can be translated to
parameters which can be measured in imaging techniques used in clinical
practice.
- Evaluate if the moment of the day, and therefore the moment of scanning,
influences the position of the pelvic organs.
- Set a standard of natural descent during the day in women without symptomatic
POP, as to compare with women with symptomatic POP with and without the use of
a pessary.
- Evaluate if there is a correlation between the position and orientation of
the pessary and anatomical aspects of the levator ani muscle.
- Evaluate which parameters differ between patients with successful (i.e.
continuation of pessary use for >= 3 months) and unsuccessful pessary fitting.

This document is a framework from which different studies will be established
in different phases. The outcome of studies in one phase can be used as input
information for the next phase. Each study is a prospective cohort study in
which the position and orientation of the pelvic organs and the pessary will be
investigated. Therefore, in each phase the Esaote G-scan Brio 0.25T MRI will be
used, in which patients will be scanned in supine as well as in upright
position. Additionally, in some of the phases other imaging techniques such as
the Siemens Magnetom Aera 1.5T MRI may be used.

In the first study the patients have to visit the University of Twente for two
days, one day with the pessary inserted and one day without. On both days they
will be scanned three times. In study 1B controls (mostly employees of the
University of Twente) will be scanned three times during one day. Those women
can work in between, and therefore the extend of burden will be restricted as
much as possible. In the other studies only one visit is needed. The patient is
not allowed to drink 60 minutes before the start of the scanning procedure and
needs to void before the start of the scanning procedure.
During the scanning procedure the patient needs to lie or stand still. In
upright position, some people may experience some dizziness because of this. To
prevent this, the patient is encouraged to move her toes between the different
scans. If dizziness is noticed, the scan will be aborted immediately and the
participant is turned back to the horizontal position. The risks associated
with MRI are negligible.