Evaluation of the patients* satisfaction and safety of a non-degradable urethral bulking agent for female stress urinary incontinence

Urinary incontinence (UI) is a major public health issue affecting up to 25-50%
of all women and has a detrimental impact on patient quality of life (1,2).
Stress urinary incontinence (SUI) is the most common form of urinary
incontinence and is defined as the leakage of urine, which occurs during
physical activity of exertion or on sneezing or coughing. It has been reported
that the prevalence of SUI is 25 to 45% of the female population (3,4).

Pelvic floor physiotherapy is the first choice of treatment and its aim to
strengthen the natural tissue support has a 33-49% chance of being effective
(5,6). Nowadays, if pelvic floor exercises fail, mid-urethral slings (MUS) are
widely used as a first-line surgical treatment. Over time, MUS has been
evaluated to be a highly effective treatment. Subjective and objective cure
rates of 91% and 85% respectively are reported (6).
An alternative treatment for SUI is urethral injection therapy. The
hypothetical mechanism of action is that by the injection of bulking agents
(BA) into the urethral submucosa, artificial urethral cushions are created that
can improve urethral cooptation and hence restore continence (7). Ideally, a BA
should be permanent and maintain its shape, giving a long-lasting effect. In
addition, BA should be biocompatible, non-degradable, non-allergenic,
non-immunogenic and does not migrate. Over decades, various bulking agents have
been developed and applied. Their biomechanical properties, effectiveness and
safety vary depending on which synthetic or biological materials were used for
the manufacturing of the bulking agent. A procedure with BA is performed in an
outpatient setting under local analgesia which can be beneficial as compared to
a tension free vaginal tape (TVT) procedure. In addition, a meta-analysis
confirmed that voiding dysfunction was less present in BA as compared to open
surgery (8). However, a Cochrane review states that there is insufficient data
to guide practice. Relief of SUI symptoms up to 12 months is reported, but the
results are inferior to open surgery. The lack of data on long-term
effectiveness makes that BA is not recommended as a first-line treatment.
Currently, only a small area of indications is reserved for BA as a treatment
for SUI. BA is used in patients who are unfit for surgery for patients with
recurrent SUI (RSUI) after MUS. Finally, some patients have a strong preference
for minimally invasive therapy and accept a lower cure rate for injectable
therapy over open surgical procedure (9,10).

In 2011 a new urethral BA was developed called Urolastic®. Urolastic® consists
mainly of a non-degradable, biocompatible polydimethylsiloxane (PDMS) polymer.
It remains flexible and adapts itself to the shape of the environment during
injection, reducing the chances of internal migration. Although small
prospective cohort studies on the safety and efficacy of Urolastic® have been
published, the results vary significantly (11-16). Reported objective success
rates range from 59,3 to 89%, subjective success rates range from 35,1 to 90%
and complication rates vary from 16,3 to 30% (11-16). Possible reasons for this
wide range could be due to the patient selection, time of follow-up and the
learning curve of the physician. Nevertheless, these data are insufficient to
determine whether Urolastic® is a reasonable treatment option for women with
SUI.

The aim of this cross sectional research is to determine the subjective
improvement of symptoms in women, the patients* satisfaction, the safety and
re-intervention rate of women who have been treated with PDMS (Urolastic®).
.

Primary Objective: To determine the subjective improvement of symptoms in women
with SUI treated with PDMS (Urolastic®)

Secondary Objectives:
- To determine the patients* satisfaction
- To determine the complications and re-intervention rate
- To determine the objective cure

Retrospective study

No extra risk is associated with the study. Patients have to revisit the
hospital for physical examination and to fill out one questionnaire.