Prospective multicentre randomised trial of tension-free vaginal tape and colposuspension as primary treatment for stress incontinence

We are grateful to Drs Varma and Neale for their comments on our
recent article.1 They refer to the high rate of complications recorded
within our trial, and in particular to the rate of bladder injury during
the Tension-free Vaginal Tape procedure (TVT). We would point out that
ours was a multicentre randomised comparative trial involving 39 operating
surgeons, of whom 15 were consultants and 24 were supervised trainees.
The 14 collaborating centres recruited between 6 and 51 patients, and
individual surgeons undertook between 1 and 29 operations (between 1 and
20 TVT procedures). Although all consultants had undergone a similar
training in the TVT procedure, they had variable experience of the
operation at the time of recruitment; we had intended that this fact,
along with the inclusion of units with a range of clinical and academic
background, and variable workload, would increase the external validity or
generalisability of the results. One would expect that a pragmatic trial
of this nature would give results and complication rates at variance with
those of smaller personal audit series, although would suggest to Drs
Varma and Neale that the rate of bladder injury in their own audit is
neither statistically nor clinically significantly different from the rate
in our own or other published series.2, 3 The perforations which occurred
with TVT within our trial were during the 1st to 13th patient (median 8th)
recruited for the procedure at individual centres. In a recent nationwide
review of cases from Finland, it is suggested that the weight of
complications occur in a surgeons first 15 cases.4 In the senior author’s
personal series of 310 TVT’s bladder perforation has occurred in case
numbers 65, 68, 144 and 276. However long the ‘learning curve’ might be,
the time for complacency at this or any other surgical procedure is never
reached.

The correspondents raise the important question as to whether the
occurrence of bladder perforation increases the risk of adverse primary or
secondary outcomes. The issue of sample size was discussed in some detail
in our paper, and the numbers involved make subgroup analysis of very
limited value. Although we did find variation in cure rates for both TVT
and colposuspension between the different centres, we did not find
significant differences in results between consultants and trainees,
urologists and gynaecologists, university teaching hospitals and district
general hospitals, nor between early and late recruits to the trial, and
those with and without urinary tract injury.5 Although 11 out of 15 (73%)
TVT patients with bladder perforation were cured at 6 months, compared to
104 of 155 (67%) where there was no such complication, a study involving
over 4400 cases would be required to answer the question which the
correspondents pose, with reasonable power. As we pointed out in our
paper, no long term sequelae have yet been reported from recognised
bladder perforation at TVT; the same is of course not true for
unrecognised operative injury or subsequent erosion into the urinary
tract, and reports of such cases are beginning to appear in the
literature,6-10 and we are aware of at least 8 such cases within the UK.

Drs Varma & Neale suggest that the success of our trial may help
dispel the myth that TVT should be restricted in its use to subspecialist
urogynaecologists. Whilst we have never personally advocated this
limitation, we would look on it as highly regrettable if readers took this
to imply that the procedure was appropriate for all surgeons to undertake.
We would wholly endorse the recommendations of the recent Royal College of
Obstetricians and Gynaecologists study group,11 and would point out in
particular the statement: “All surgical procedures should be undertaken
only by those with appropriate training and experience to allow them to
maintain the highest standards of practice.” Appropriate training for TVT
has never been satisfactorily defined, although we would suggest that
considerable experience in cystourethroscopy and in retropubic surgery are
essential pre-requisites,12 and supervised management of at least 15 cases
should be considered desirable.

Competing interests: see original paper.1

1. Ward KL, Hilton P. Prospective multicentre randomised trial of
tension-free vaginal tape and colposuspension as primary treatment for
stress incontinence. British Medical Journal 2002;325:67
(http://bmj.com/cgi/reprint/325/7355/67).

2. Merlin T, Arnold E, Petros P, MacTaggart P, Tulloch A, Faulkner K, et
al. A systematic review of tension-free urethropexy for stress urinary
incontinence: intravaginal slingplasty and the tension-free vaginal tape
procedures. British Journal of Urology International 2001;88(9):871-880.

3. Hinoul P, Rufford J, Cardozo L, Bidmead J, Anders K, Dixon A, et al.
TVT: Trouble-free Vaginal Tape? In: International Continence Society (UK
section); 2002; Sheffield; 2002.

4. Kuuva N, Nilsson CG. A nationwide analysis of complications associated
with the tension-free vaginal tape (TVT) procedure. Acta Obstetricia et
Gynecologica Scandinavica 2002;81(1):72-77.

5. Hilton P. Trials of surgery for stress incontinence - thoughts on the
'Humpty Dumpty principle'. British Journal of Obstetrics & Gynaecology
2002;(in press).

6. Koelbl H, Stoerer S, Seliger G, Wolters M. Transurethral penetration of
a tension-free vaginal tape. British Journal of Obstetrics &
Gynaecology 2001;108(7):763-5.

7. Haferkamp A, Steiner G, Muller SC, Schumacher S. Urethral erosion of
tension-free vaginal tape. Journal of Urology 2002;167:250.

8. Pit MJ. Rare complications of tension-free vaginal tape procedure: late
intraurethral displacement and early misplacement of tape. Journal of
Urology 2002;167:647.

9. Madjar S, Tchetgen MB, Van Antwerp A, Abdelmalak J, Rackley RR.
Urethral erosion of tension-free vaginal tape. Urology 2002;59(4):601.

10. Sweat SD, Itano NB, Clemens JQ, Bushman W, Gruenenfelder J, McGuire
EJ, et al. Polypropylene mesh tape for stress urinary incontinence:
complications of urethral erosion and outlet obstruction. J Urol
2002;168(1):144-6.

11. Cardozo L, Maclean A. Incontinence in Women: Proceedings of the 42nd
RCOG Study Group: RCOG; 2002.

12. Hilton P. Tension-free Vaginal Tape: the minimalist approach to
continence surgery. In: Sturdee D, Oláh K, Keane D, editors. Yearbook of
Obstetrics and Gynaecology - Volume 10. London: RCOG Press; 2002.