[Study on estrogen receptor around levator ani muscle for female stress urinary incontinence]

To explore the relationship between estrogen receptor and the occurrence of stress urinary incontinence (SUI) through analysis on estrogen receptor (ER) around levator ani muscle.

The biopsy specimens around levator ani muscle were obtained from 31 subjects undergoing total vaginal hysterectomy (TVH), laparoscopic assistant hysterectomy (LAVH) and tension-free vaginal tape (TVT) procedures, who were assigned in to control, pelvic organ prolapse (POP) and SUI groups. The histological structures around levator ani muscle were examined with routine HE staining. ER in structures around levator ani muscle was evaluated by immunohistochemical staining.

ER positive staining rate in levator ani muscle and surrounding tissues was 6.7% among total samples. ER positive staining located in nuclei of connective tissue, smooth muscle and small nerve cells. The positive rate in connective tissue, smooth muscle and small nerve cells was 1.4%, 4.7%, 5.7% in control group, 1.1%, 2.8%, 2.7% in SUI group and 4.1%, 9.5%, 11.6% in POP group, respectively. It was significantly lower in SUI group than that in control group (P < 0.01), and POP group (P < 0.01).

There is close relationship between degeneration of pelvic support construction and deficiency in ER around levator ani muscle. ER positive staining in SUI group was significantly lower than that in POP group, suggesting that decrease of ER around levator ani muscle in POP might lead to the occurrence of SUI.