ORIGINAL PAPER A. Liapis á P. Bakas á A. Pa®ti á D. Hassiakos M. Frangos-Plemenos á G. Creatsas Changes in the quantity of collagen type I in women with genuine stress incontinence Received: 16 December 1999 / Accepted: 7 April 2000 Abstract The aim of this study, was to examine changes in the quantity of collagen type I in the pubocervical fascia of women with genuine stress incontinence GSI), with and without pelvic relaxation . Seventy-eight patients participated in the study and they were divided into three groups that were comparable with respect to their age and parity. All the patients underwent ®lling cystometry and patients with detrusor instability were excluded from the study. Biopsies were obtained from the pubocervical fascia. The presence of collagen type I was determined with an immunohistochemical tech- nique. The X-test was used for statistical analysis and a P<0.05 was considered statistically signi®cant. Colla- gen type I was signi®cantly reduced in patients with GSI irrespective of the presence or absence of genital prolapse. Thus we found that women with GSI had a signi®cant reduction of collagen type I in the pubocer- vical fascia which consequently aects the tensile strength of the pubocervical fascia and the support provided to the bladder neck. Key words Collagen Type I á Genuine stress incontinence á Genital prolapse Introduction Genuine stress incontinence GSI) is believed to be caused by inadequate support of the bladder base and bladder neck or insuciency of the urethral sphincter [1, 3]. The adequate function of the pubourethral liga- ments, the pubococcygeal muscle and the connective tissue of the suburethral wall pubocervical fascia) is important for urinary continence in women [6]. The main constituent of the connective tissue of the pubocervical fascia is collagen [9]. The quantity and organization of collagen ®bers aects signi®cantly the tensile strength of the pubocervical fascia and conse- quently the support that is provided to the bladder neck and bladder base. A reduction in total collagen content of pubocervical fascia in women with GSI has been found [4, 7] but which type of collagen is reduced mainly needs to be investigated further. The aim of the study was to evaluate changes in the quantity of type I collagen in patients with GSI as compared with conti- nent women independent of the presence of pelvic relaxation. Material and methods Seventy-eight patients participated in the study. Their age ranged from 34 to 75 years old mean 52.8 + 7.6) and their parity ranged from 1 to 4 deliveries mean 2.3 + 1.15). Forty-one patients were postmenopausal and 37 were premenopausal. None of them was receiving or had received hormone replacement therapy in the past. All the patients underwent ®lling cystometry and patients with detrusor instability were excluded from the study. Approval from the ethical committee of our hospital and informed consent was obtained from all participants in the study. The patients were divided in to three groups according to the ®ndings at clinical examination and urodynamic investigation, as follows: 1) 32 patients with GSI and genital prolapse in group I, 26 patients with genital prolapse but without GSI in group II and 20 patients with neither genital prolapse nor GSI in the control group. All the groups were comparable with respect to their age, parity Table 1). Biopsies were obtained during surgery from the pubocervical fascia at the level of the bladder neck. The balloon of the Foley catheter that was inserted in to the bladder at the time of the operation was used as a guide for recognition of the bladder neck. The patients of group I and group II had stage I pelvic organ prolapse, according to the International Continence Society classi®cation and the presence of genital prolapse was assessed during straining with the patient in lithotomy position. All biopsies were obtained Urol Res 2000) 28:323±326 Ó Springer-Verlag 2000 A. Liapis &) N. Paritsi 9 A, N. Psychiko, Athens, Greece, P.C: 15451 Tel.:+30-1-6727199; Fax:+30-1-6712188 P. Bakas á D. Hassiakos á G. Creatsas 2nd Department of Obstetrics and Gynecology, Aretaieio Hospital, University of Athens, Greece A. Pa®ti á M. Frangos-Plemenos Histopathology Department of Aretaieio Hospital, University of Athens, Greece