The aim of the study is to evaluate the effects of local estriol treatment applied before vaginal repair surgery on steroid receptors, inflammatory cell response, vascular, connective and nervous tissues in the vagina, and its effects on early postoperative period pelvic floor functions, satisfaction with the surgery and vaginal health.

Pelvic organ prolapse (POP) is the herniation of pelvic organs into or beyond the vaginal walls and is a common health problem that affects daily activities and sexual function. Its negative impact on women's quality of life has been the subject of clinical research all over the world due to the economic burden it brings to the healthcare system.

The use of different classification systems for diagnosis and the fact that many women with mild prolapse are asymptomatic make it difficult to determine the exact prevalence of pelvic organ prolapse. Among women aged 50-79, the prevalence is 41% and the lifetime risk of prolapse surgery is 11%. This risk is expected to increase in the future.

Advancing age and postmenopausal status are known risk factors for pelvic organ prolapse. Since estradiol receptors alpha and beta (ESR1/2) are found in the squamous epithelium of the bladder, urethra, vagina, and pelvic floor muscles, it is evident that the pelvic organs and their surrounding muscle and connective tissue are sensitive to estrogen and that menopause is an important risk factor for the development of pelvic organ prolapse. The decline in estrogen during the postmenopausal period contributes not only to symptoms of pelvic organ prolapse but also to other pelvic floor disorders, including vulvovaginal atrophy, stress urinary incontinence (SUI), urge urinary incontinence (UUI), sexual dysfunction, and dyspareunia.

Studies show that estrogen levels have a significant impact on the function of the genital and lower urinary tract. Estrogen regulates the function of the vascular smooth muscles in the vaginal wall, affecting vaginal wall perfusion and smooth muscle tone. It also regulates bladder smooth muscle contractility, cellular and extracellular composition, and nerve density.

Local estrogen therapy (LET) works by increasing vaginal tissue blood flow, epithelial thickening, increased epithelial secretion and decrease in vaginal pH. From a physiological and psychosocial perspective, women using estrogen therapy describe positive effects such as normalization of sexual function, increased quality of life, improvement in relationships with their spouses, feeling 'less old', higher self-esteem and having a better social life.

In recent years, local estrogen therapy has become the focus of treatment of pelvic floor disorders. Various conservative and surgical methods have been described in the treatment of pelvic organ prolapse. Conservative treatment methods include topical estrogen. Among the surgical approaches, many vaginal and abdominal methods with or without graft material have been described. Surgical methods are mostly preferred in treatment.

The primary goal of POP surgery is to reduce symptoms and improve health-related quality of life. However, despite the continuous evolution in current surgical techniques, recurrence of symptoms is common. It is important to find ways to improve pelvic organ prolapse surgery outcomes. It is unclear whether preoperative LET is beneficial. Ismail and colleagues concluded in a Cochrane systematic review that further studies with long-term follow-up are needed to evaluate the effects of estrogen preparations before prolapse surgery.

The aim of this study is to evaluate the effects of preoperative local estriol application on the vaginal tissues and the effects of preoperative local estriol application on early postoperative period pelvic floor functions, satisfaction with the surgery and vaginal health in postmenopausal women planned for vaginal repair surgery.

As a result, steroid receptors (ER, PR, AR), immune cell types and distribution, CD34 and vascular endothelial density, collagen fiber density, S100 in the anterior and/or posterior vaginal wall in patients with and without local estriol treatment before colporrhaphy anterior and/or posterior. The difference in nerve fiber density and epithelial maturation index levels will be investigated. In addition, the Pelvic Floor Distress Inventory (PFDI-20), which is valid in Turkish, Pelvic Floor Impact Questionnaire (PFIQ-7), Patient General Impression of Improvement (PGI-I) and VAS scoring and early postoperative pelvic floor functions were evaluated in the study and control groups before and after surgery. and patient satisfaction regarding the surgery will be compared. There will also be comparisons between the pre-surgical study and control group through the vaginal health index (VHI), which is a quantitative assessment of vaginal health. Follow-ups are planned to be carried out with the patients' routine check-up visits to the hospital.

Inclusion Criteria:

-Postmenopausal women with a diagnosis of pelvic organ prolapse and an indication for vaginal repair surgery including colporrhaphy anterior and/or posterior surgery

Exclusion Criteria:

• Psychiatric and neurological disease that causes disability in mental and motor functions
• receiving systemic/local hormone replacement therapy in the last three months
• applying vulvar/local steroids for any reason within the last three months
• receiving treatment for pelvic and/or lower genital tract infection in the last three months
• history of malignancy
• previous vaginal repair surgery with/without mesh

pathologist who will examine the tissue samples in the study