Computerised morphometric study of the paraurethral tissue in young and elderly women

Changes in structural support of the urethra and bladder neck have been proposed to be among the most important factors in the pathogenesis of stress urinary incontinence. In this context, we histologically investigated the paraurethral area in continent women to quantify the relative distribution of connective tissue, smooth muscle, vessels, nerves, and striated muscle. Previously published literature gives only descriptive evaluations of the relative distribution of these tissue components.

We used a computerised morphometric method, which allowed us to estimate the paraurethral tissue distribution in a more objective way. The material was obtained by dissection during autopsy in five premenopausal and five postmenopausal women.

Paraurethral tissue consisted of 56% connective tissue (SD, 5%), 30% smooth muscle (SD, 5%), 11% blood vessel (SD, 6%), 2% striated muscle (SD, 3%), and 1% nerves (SD, 1%). We also found that the distribution of different tissue components along the length of the urethra did not differ at a statistically significant level. Furthermore, there was a statistically significant difference in the amount of connective tissue and blood vessels in the postmenopausal women compared with the premenopausal women.

The present study shows that the paraurethral area is built of heterogeneous tissue with small changes in its composition along the course of urethra. Increase in connective tissue was found to be the dominating change in the process of ageing.