Discussion:
Main findings:
The Cumberledge enquiry has highlighted a lack of long-term outcomes for
the mid-urethral tape procedures (MUS)1. As
recommended in this inquiry, as well as the ICI
guidelines10, patient perception of outcomes using
patient reported outcome measures (PROM’s) were used to evaluate long
terms outcomes 12 years after TVT and TOT procedures. PROMS’s used in
this follow-up as well as the original study, reduces the bias of health
care personnel’s impression of outcome. The 12year results show that TVT
is superior to TOT for cure of stress urinary incontinence in the
long-term and that the two procedures are comparable in terms of
complications. However, there was a decline in success and satisfaction
with time, as seen with other surgeries for SUI such as colposuspension.
For the assessment of success, the primary study defined ‘cure’ as
‘never’ on the ICIQ FLUTS questionnaire Q8a: “does urine leak when you
are physically active, exert yourself, cough or
sneeze?”7. The same was used in this long-term
follow-up study. This might be regarded as a strict definition. For
example, there was a large proportion of women in this study who
reported SUI ‘occasionally’ only i.e. 35% TVT and 36% TOT. This level
of incontinence was not regarded as bothersome. Despite the lower
subjective success rate, both the TVT and TOT produced significant
improvement in symptoms according to the PGI-I for the majority of
participants.
Objective and subjective cure rates for the MUS differ depending on the
length of follow up, criteria used for definition of cure and the
instruments used for assessing cure e.g. questionnaires, pad tests or
urodynamic findings. The long term (>5 years) efficacy and
safety of the MUS procedures are summarised in a systematic review by
Maggiore and colleagues11. They report an objective
cure rate for the TVT and TOT procedures of 57.2% and 68.8%
respectively11. Nilsson and colleagues reported a 90%
objective continence rate following retropubic tape procedure based on
cough test, and 87% continence rate based on PGI-I at 17 years
follow-up12. Since then further reports on long-term
efficacy on all types of MUS have been published with cure of SUI
ranging from 65% to 97%13,14,15,16.
Interpretation:
These differences in outcomes can also be attributed to the patient
population, with studies with higher cure rates excluding patients with
mixed incontinence. Our study includes patients with SUI-predominant
mixed incontinence. It is therefore recommended that all studies use
standardised outcome measures which will enable systematic reviews and
meta-analyses to inform clinical practice and patient counselling e.g.
as recommended by ICI10.
The mid-urethral sling procedure was placed under high vigilance
restriction by the FDA in 2011 and the UK NHS Improvement (NHS England)
in 2018. This was secondary to reports of pain and complications in some
women following tape insertion and highlighted in the Cumberledge
report1. This led to public campaigns and legal action
to raise awareness along with subsequent media
reports17. The true extent of the problem is unclear
thus this study aimed to assess the proportion of women who reported
pain and its severity long-term. The results showed that the majority of
women were pain-free. For those who reported moderate pain, it did not
have a significant impact on quality of life and surgical intervention
was required for a minority. For the 6% of women with severe pain,
their quality of life was diminished. It is therefore important to
emphasise the need for appropriate pre-operative counselling about this
risk. Early surgical intervention for complication management is
recommended to achieve symptom resolution18.
An attempt to understand why women have a different response to the same
treatment is important. Greater attention to patient selection,
preoperative assessment and surgical technique might be critical to
optimizing outcomes from the procedures19.
Our study respondents are 12 years older and it could be argued that the
urinary urgency and UUI reported
are a result of ageing rather than the long-term effects of
surgery20. However, comparison of the baseline
prevalence with the 12year follow-up data confirmed a decrease in the
number of participants reporting these symptoms. The population
recruited to the original trial was comprised of women with mixed
incontinence: 93.5% TVT and 97% TOT group had reported any UUI prior
to their surgery and 87% TVT and 89% TOT group reported any urinary
urgency7. Consequently, though the prevalence of UUI
and urinary urgency at 12 years is deemed high, comparison with the
baseline prevalence of both symptoms confirms a reduction of these
symptoms at 12 years for both the TVT and TOT groups. In addition,
urinary urgency and UUI did not represent significant bother for the
majority of patients.
Strengths:
A number of studies exist, which analyse the long-term outcomes of MUS.
This study represents one of few studies which specifically compares the
efficacy and complications between the TVT and TOT procedures in the
long term. The study thus provides unique information on the superior
efficacy of the TVT procedure in direct comparison to the TOT procedure
in a randomised controlled trial setting.
Additionally, we specifically addressed the pain and complications issue
presented by the adverse media reports, by using both a numeric rating
scale for pain and a free text space for additional comments. This has
the advantage of giving the patients a platform to report any issues
they have experienced with the tapes. We are confident that the
participants report of no complications was accurate, as it is possible
that the adverse media reports could result in patient anxiety and
self-referral for assessment. Thus, the inclusion of a free text box for
added comments represents a strength of the study.
Limitations:
Statistical analysis could not be performed to compare pain scores
between the TVT and TOT procedures because the majority of respondents
(>80% in both groups) reported no pain. However, the trend
for no difference between the groups is apparent.
Additionally, analysis of all returned questionnaires at 12 years was
limited as there was incomplete information from 11 participants from
the 1year study. Consequently, despite receiving 121 returned
questionnaires, paired ICIQ-FLUTS analysis between long- and short-term
outcomes could only be performed on 110 participants, reducing the data
available for analysis from 70% to 64%.
Due to the UK research governance regulations, General Practitioner
records could not be accessed to identify other issues which were
managed in the community. Likewise, the hospital records of those
patients who had not given consent for participation in this follow- up
trial could not be accessed. This represents the main limitation of the
study. The response rate of 70% could have been improved if further
reminders had been sent, but only one was allowed by research ethics.