- Correlation of urodynamic results and urethral coaptation with
success after transurethral collagen injection
KIM, Y. H.; KATTAN, M. W.; BOONE, T. B.
Scott Department of Urology, Baylor College of Medicine, Houston, Texas. Urology, v.50,
Objectives: We correlated preoperative urodynamic and
intraoperative endoscopic findings with initial improvement, single collagen injection
effectiveness for intrinsic sphincter deficiency (ISD), and long-term improvement
following transurethral collagen injection for stress urinary incontinence (SUI).
Material and Methods. Since 1993, 79 patients have been treated
with transurethral collagen injection by the same urologist. Of these patients,
intraoperative photographs of urothelial coaptation immediately after injection were
available in 67 patients: 35 women with ISD, 24 men with incontinence, primarily following
prostatectomy, and 8 children with neurogenic bladder. Urothelial coaptation was described
as snug, fair, or poor. Preoperative Valsalva Leak Point Pressure (VLPP), detrusor
instability, impaired bladder compliance, bladder neck appearance, urothelial scarring,
and degree of coaptation were correlated with both initial and long-term improvement.
Initial improvement was compared with long-term improvement.
Results: Initial improvement was experienced by 85% of all the subjects (86% of the
women, 80% of the men, and 100% of the children with a neurogenic bladder condition).
Overall, 31% of patients had long-term improvement after a mean follow-up of 2.2 years,
including 43% of the women, 13% of the men, and 33% of the children. The patients
underwent a mean of 1.5 (1 to 4) collagen injections. There was a significant correlation
between degree of coaptation and initial improvement (P = 0.003), but not with long-term
improvement. There was no correlation between VLPP, detrusor instability, impaired
compliance, bladder neck appearance, or urethral scarring and initial improvement. There
was no correlation between any parameter and long-term improvement or between initial and
Conclusions: Initial endoscopic appearance following collagen injection predicted
initial, but not long-term, improvement after one collagen injection. Initial improvement
was high in both men and women but decreased considerably over time, more so in men, and
was not significantly correlated with long-term success. Urodynamic and endoscopic
findings do not predict long-term success following collagen injection.
The authors try to correlate urodinamic pre-operative and
intra-operative endoscopic parameters with the initial and final results of the
transurethral injection of collagen in the treatment of the stress urinary incontinence.
In relation to the predictive value for insucess, other authors found contrary results in
relation to the study of Kim et al. In these articles detrusor instability is considered
an adverse factor in relation to the success of the treatment1,2.
The determination of factors to predict success could be useful in the improvement of the
relationship cost-benefit of the use of this treatment, being taken in consideration the
high costs of this therapy and the possible need of multiple injections. Unfortunately, as
it demonstrates this article, although the endoscopic appearance of the bladder neck is
correlated with the initial improvement, no parameter is capable to predict long-term
success of the therapy.
1. HERSCHORN S.; RADOMSKI, S.B.; STEELE D.J. Early experience with
intraurethral collagen injections for urinary incontinence. J. Urol., v.148, p.1797-00,
2. OCONNELL, H.E.;McGUIRE, E.J.; ABOSEIF, S et al. Transurethral
collagen therapy in women. J. Urol., v.154, p.1463-5, 1995.