Purpose: Transurethral collagen injection therapy has been used succes
sfully in treating stress urinary incontinence due to intrinsic sphinc
ter deficiency since United States Food and Drug Administration approv
al in October 1993, Materials and Methods: Telephone interview and cha
rt review were performed on 139 women with intrinsic sphincter deficie
ncy documented using video urodynamics, of whom 73% had grade 3 incont
inence (leakage without effort). Median followup was 18 months (range
6 to 36). Median patient age was 72 years. Results: A total of 103 pat
ients (74%) was substantially improved after collagen therapy, 29 (20%
) were improved and 7 had no improvement. Of the substantially improve
d group 72% obtained continence after 2 or fewer injections. Of the pa
tients 11% required a ''booster Injection more than 6 months after ini
tial treatment. Complications, such as hematuria, urinary tract infect
ions or transient urinary retention, were rare. Conclusions: Our resul
ts confirm the safety and efficacy of transurethral collagen. Once con
tinence is achieved further collagen therapy is rarely necessary.