Female stress urinary incontinence is a common and frequent disease in women, 35% to 45% of women have different degrees of urinary incontinence symptoms, of which stress urinary incontinence accounts for the majority, and with increasing age, the incidence increases and symptoms worsen, which seriously affects the quality of life of patients. With the increase in human life expectancy and quality of life requirements, stress urinary incontinence is receiving increasing attention. I. Definition: International Continence Society (ICS) definition: It refers to the involuntary overflow of urine from the external urethral opening due to an increase in intra-abdominal pressure (e.g., during coughing, sneezing, exercise) in the absence of contraction of the detrusor muscle. Characteristics: No leakage in the normal state, but automatic urine outflow when abdominal pressure is suddenly increased. Second, clinical epidemiology: 1, the prevalence of prevalence varies, generally between 23% to 45%, severe incontinence in 3% to 10%, about half for stress incontinence, the rest for urge incontinence and mixed incontinence. Foreign reports 41.6% to 81%, the United States about 15% to 60%, domestic reports about 40%, 40 years of age and above in women, every 10 years of age, stress incontinence increased by 10%, to 60 years of age and above up to 61.54% 2, related factors: (1) age It is usually believed that age and the prevalence of stress incontinence is related to the increase in age, Minassian et al. The peak age of SUI incidence is 45-55 years old, (2) childbirth It is usually believed that huge children are prone to excessive stretching of the uterus, bladder neck and tissues around the urethra during pregnancy and delivery due to their large size, and cause prolonged labor, resulting in urinary incontinence. Starting labor too soon after delivery can exacerbate existing damage to the pelvic floor during pregnancy and delivery, leading to urinary incontinence. Urinary incontinence is strongly correlated with forceps/vacuum suction, lateral episiotomy and perineal suturing. （SUI and POP are strongly correlated, with 50% of patients with POP having SUI and 80% of patients with SUI having POP, and the degree of pelvic organ prolapse is significantly correlated with the severity of SUI. The degree of pelvic organ prolapse was significantly and positively correlated with the severity of SUI. (4) Race and genetic history Genetic factors have a clear correlation with SUI, and the prevalence of SUI is significantly correlated with the prevalence of their immediate family members. The prevalence of urinary incontinence also differs between races, with whites having a higher prevalence than blacks, 27% and 14%, respectively. (5) Obesity It is well established that obesity is a causative factor for urinary incontinence or aggravates the degree of incontinence 3. Possible associated risk factors: (1) Hysterectomy (2) Estrogen The role of menopause and estrogen loss in the development of urinary incontinence is controversial. At this stage, treatment of SU I with hormone replacement therapy remains controversial. (3) Medical history Fritel et al. suggested that diabetes mellitus, diuretic use, urinary tract infection, previous gynecological surgery, constipation, fecal incontinence, perineal suturing, exercise, radiotherapy, impaired function of the levator muscle, enuresis in childhood, respiratory disease, nocturnal awakening, dementia, stroke, depression, and congestive heart failure may be risk factors for stress urinary incontinence. (4) Lifestyle (5) Diet Full fat intake (especially saturated fatty acids) is significantly associated with the occurrence of SUI, and increased cholesterol intake also increases the risk of SUI. The micronutrients zinc and vitamin B12 were positively associated with the occurrence of stress urinary incontinence. Carbonated beverages are a risk factor for stress urinary incontinence and bread reduces the risk of stress urinary incontinence. Carbohydrate is a protective factor for the development of SUI. (6) Other Occupation, education, and type of residence: are associated with the occurrence of urinary incontinence. Those who engage in manual labor are susceptible to SU I. It may be related to the increase in abdominal pressure easily caused by long-term physical labor, the prevalence of SU I in heavy manual labor is 53.0%, 18.0% in housewives, and 15.4% in brain workers. This may be related to a larger proportion of mental labor, fewer births, and strong awareness of health care among the highly educated. Pathophysiological mechanism: 1, early theory; that the normal anatomical position of the bladder neck plays an important role in urinary control, leading to urinary incontinence when the bladder neck position decreases; 2, “hammock” (hammock ) hypothesis: 1994 De Lancey proposed the formation of the pubic urethral ligament under the urethra The “hammock” is the main anatomical structure that supports the urethra, prevents the bladder neck from moving down, and maintains urinary self-control. When the abdominal pressure increases, the contraction of the “hammock” exerts a squeezing effect on the urethra, followed by an increase in urethral closure pressure, which closes the urethra to control urination, rather than the result of intra-abdominal pressure on the urethra in the abdominal cavity. Urinary incontinence symptoms occur when the supporting tissue is weak or damaged. (1) Increased urethral mobility: Because of the relaxation of the pelvic floor, the bladder neck and proximal urethra move downward, when the abdominal pressure increases, the pressure cannot be transmitted to the proximal urethra, and the original pressure gradient of the urinary bladder no longer exists, so urinary leakage occurs. Surgery, urethral surgery or injury or neurological lesions make the proximal urethra and bladder neck poorly aligned and open for a long time, which will lead to urine leakage if the abdominal pressure increases. Based on the two theories mentioned above, many surgical treatments have been developed: 1. Early treatments: The aim is to elevate the bladder neck to its normal anatomical position, i.e. in the pelvis, but there are problems of recurrence of symptoms and urinary tract obstruction. 2. 2. Newer treatment methods: The main purpose is to strengthen the role of the supporting structures around the urethra, rather than changing the position of the bladder and urethra and the angle between them. 1) TVT surgery principle “tension-free mid-urethral suspension”: Invented by Swedish Ulmsten in 1996 similar to rectus abdominis fascia bladder neck suspension surgery. VI. Precautions: 1. Intraoperatively, it should be ensured that the sling is placed tension-free; 2. Postoperatively, attention should be paid to the presence of common complications such as infection, hematoma, urethral compression, difficulty in urination, instability of the forced urinary muscles; 3. Daily activities can be performed after 1 to 2 weeks postoperatively; 4. Avoid lifting heavy objects and strenuous exercise for 1 month postoperatively; 5. Avoid sexual intercourse for 1 month postoperatively. In conclusion, TVT-O is easy to operate, less traumatic, and the degree of sling suspension can be adjusted at will, especially without bladder injury complications. It is undoubtedly the best choice for elderly patients with medical comorbidities.