Stress urinary incontinence (SUI) has a high incidence in middle-aged and elderly women and seriously affects the quality of life of patients. The treatment of female stress urinary incontinence is divided into two categories: conservative and surgical. Conservative treatment mainly includes pelvic floor muscle exercise, biofeedback therapy, electrical stimulation and extracorporeal magnetic therapy, etc. Surgical treatment is mainly for patients with SUI, repairing the urethra and bladder neck support system, increasing the function of the sphincter closure system, and establishing a new urinary control mechanism.
Stress urinary incontinence refers to the involuntary discharge of urine in the absence of contraction of the detrusor muscle when the abdominal pressure is greater than the maximum urethral pressure. International epidemiological studies show that female urinary incontinence has become one of the five major chronic diseases that threaten women’s physical and mental health, and its medical costs have surpassed those of breast cancer, osteoporosis and depression. To date, there are approximately 200 million patients with stress urinary incontinence worldwide, which seriously affects the daily life and work of patients. Therefore, its diagnosis and treatment are receiving increasing attention.
1.Female pelvic floor anatomy
The female pelvic floor is composed of multiple layers of muscles and fascia to close the pelvic outlet,
The muscles, fascia, ligaments and nerves work together to maintain the normal position and function of the uterus, bladder, rectum and other organs in the pelvic cavity. The pelvic floor is divided vertically into three chambers: anterior chamber including anterior vaginal wall, bladder and urethra, middle chamber including top of vagina and uterus, and posterior chamber including posterior vaginal wall and rectum, thus quantifying uterine prolapse into each chamber. The anatomical and morphological characteristics of the female pelvic floor in vivo can be effectively studied by MRI.
2. Risk factors for female stress urinary incontinence
Female pelvic floor dysfunction (PFD) is a group of gynecological diseases with pelvic organ prolapse (POP), stress urinary incontinence and chronic pelvic pain (CPP) as the main symptoms. This damage can be direct mechanical damage to the pelvis, or indirect damage to the pelvic muscles caused by damage to the pubic nerves and nerve atrophy, which are the main causes of postpartum SUI.
2.1 Vaginal delivery and pregnancy Vaginal delivery is currently recognized as the risk factor most closely associated with POP, which may be related to pelvic floor muscle, connective tissue and nerve damage caused by delivery. However, the protective effect of cesarean delivery is limited, and cesarean delivery after prolonged labor is not protective. In addition, studies have shown that pregnancy itself is one of the risk factors for the development of POP. Other obstetric risk factors that may be associated with POP include: large babies, prolonged second stage of labor, and age at first delivery <25 years. Pregnancy and childbirth are among the major risk factors for POP, which is closely related to the damage they cause to the supporting structures of the pelvic floor.
2.2 Age and menopausal status POP is prevalent in older women, and the risk of POP increases by approximately 40% with each 10-year increase in age. Postmenopausal women are at risk for POP, and low estrogen levels after menopause are one of the risk factors for POP, and postmenopausal hormone replacement therapy (HRT) has a protective effect on POP.
2.3 Obesity and chronic intra-abdominal pressure increase Obesity is closely related to pelvic floor dysfunctional diseases, especially with urinary incontinence has a definite relationship. Chronic increased intra-abdominal pressure is also often considered as one of the risk factors for POP. Factors causing chronic increased intra-abdominal pressure include: chronic cough, long-term constipation, and repetitive weight-bearing labor.
2.4 History of previous pelvic surgery The role of history of pelvic surgery in the pathogenesis of POP is receiving increasing attention.
2.5 Congenital and genetic factors It has been hypothesized that POP may be associated with congenital or genetic factors, and that there are racial differences in the occurrence of POP, with white women having a higher risk of developing POP than Asian and African-American women.
3. Treatment of female stress urinary incontinence
3.1 Non-surgical treatment
This includes lifestyle interventions, behavioral therapy, physical therapy, and pharmacotherapy.
3.1.1 Lifestyle interventions include weight control, reduction of caffeine intake, smoking cessation, control of respiratory disease, and treatment of constipation. In addition, patients with SUI should also balance fluid intake to avoid excessive fluid intake leading to frequent and urgent urination.
3.1.2 Pharmacological treatment: There are two main types of pharmacological treatment for SUI: one is α-adrenergic agonist, which is good for urinary control; the other is estrogenic drugs, which are effective for elderly people or mild SUI with estrogen deficiency, but less effective for people with normal hormone status and heavy UI. 3.1.3 Catheters, urinary pads and urethral plugs and other devices: This method is suitable for those who have no effect or no significant improvement on other treatments. Those who are ineffective or have no significant improvement; patients in poor physical condition or unable to cooperate with relevant treatment; temporary measures before waiting for surgical treatment.
3.1.4 Pelvic floor electromagnetic stimulation:The electrodes used in clinical applications are anal or vaginal probe electrodes, implantable sleeve or linear electrodes and skin surface electrodes. These electrodes provide reflex stimulation of the pubic and pelvic nerves or direct neuromuscular stimulation to enhance muscle strength for the treatment of SUI.
3.1.5 Pelvic floor muscle exercise (PFMT): Also known as Kegel exercise, it was first proposed by Arnold Kegel in 1948. It is the most commonly used non-surgical treatment for SUI and an effective measure to prevent SUI. PFMT is an excellent adjunct to consolidate the efficacy after surgery or with medication and physical therapy.
3.1.6 Behavioral therapy: Behavioral therapy, also known as bladder exercise, habitual exercise, bladder training, bladder re-education, refers to the modification of one’s own urinary behavior to regain urinary control or partial urinary control, this modified treatment has a better effect on patients with urinary frequency, urinary urgency and urge urinary incontinence.
3.2 Surgical treatment
Surgical treatment of SUI in women refers to the reconstruction of pelvic floor support structures through repair and tissue replacement. The 3 principles of pelvic floor repair are defect repair, structural reconstruction, and tissue replacement. The treatment routes are transabdominal surgery, transvaginal surgery and laparoscopic surgery.
3.2.1 Traditional open surgery
Traditional surgical methods include: anterior vaginal wall folding, suprapubic cystourethral suspension, sacro-pubic ligament urethral bladder suspension and Stamey puncture bladder neck suspension, etc. They have many disadvantages such as large trauma, intraoperative bleeding, unsatisfactory results and high recurrence rate, and are rarely used in clinical practice.
3.2.2 Bladder neck filler injection treatment
Surgery using local anesthesia, two or more points are selected around the urethra, and the filling material is injected into the submucosa of the bladder neck through the urethra or urethral bypass to increase the closure pressure at the bladder neck, but these substances can cause chronic inflammation, foreign body giant cell reaction, periurethral abscess, vesicourethral erosion or even displacement to the internal organs, pulmonary embolism, so some scholars suggest that SUI injection therapy should be eliminated .
3.2.3 Female pelvic floor reconstruction
It refers to a new type of surgery represented by vaginal repair with mesh and sling according to the quantitative staging system of pelvic organ prolapse assessment system to grade the degree of pelvic organ prolapse, such as the surgery of reinforced repair with mesh in the anterior vaginal wall and the posterior vaginal suspension (belt) with mesh, which are minimally invasive, restore the anatomical position and function, and at the same time can reduce recurrence and avoid secondary surgery.
3.2.4 Artificial urethral sphincter implantation
This procedure uses an artificial urethral sphincter, a liquid-filled solid silicone elastic prosthesis, which is a semi-automatic closed mechanical device consisting of a control pump, a pressure-regulating reservoir, and a urethral closure cuff. The control pump is implanted in the female labia majora, and when the fluid is filled, the pressure of the closure cuff increases, which closes the urethra and controls urinary incontinence.
3.2.5 Sling procedure
Depending on the type of sling and the surgical route, slinging has different names, such as transvaginal tension-free midurethral suspension (TVT), transvaginal suspension (IVS), transocclusive bladder neck suspension (TOT), reverse transocclusive suspension (TVT-O), suprapubic cystourethral suspension (SPARC) and In-Fast bladder neck suspension.
Currently, the TVT procedure is widely accepted. The sling material for TVT is a Pristine mesh belt with barbed woven edges, and because of its barbed weave, the mesh belt can be directly attached and fixed to the tissue. The procedure is done under local intravenous anesthesia or epidural anesthesia, and the patient can be supported intraoperatively with an increase in abdominal pressure so that the sling is positioned appropriately for tension-free urethral support. The cure rate is 84% to 90% for patients with primary SUI, 80% for mixed incontinence, and about 73% for SUI with urethral internal sphincter disorder. If the patient has gynecological disorders such as anterior vaginal wall bulge, the related surgical treatment can be performed simultaneously with TVT surgery, and the incidence of postoperative complications is significantly reduced.
In conclusion, stress urinary incontinence is a common and frequent disease in middle-aged and elderly women, and many scholars at home and abroad are studying it. With the introduction of the “hammock doctrine”, the treatment of stress urinary incontinence has changed dramatically, and TVT and related surgical procedures based on it have become the gold standard for the treatment of stress urinary incontinence with their advantages of minimally invasive, safe, low complications and good long-term efficacy.