1, the more clearly related factors
(1) Age: The prevalence of female urinary incontinence gradually increases with age, with a high incidence at the age of 45 to 55 years. The correlation between age and urinary incontinence may be related to the relaxation of the pelvic floor, estrogen reduction and degenerative changes in the urethral sphincter that occur with age. Some common diseases of the elderly, such as chronic pulmonary disorders and diabetes mellitus, can also contribute to the progression of urinary incontinence. However, the incidence of stress urinary incontinence tends to slow down in the elderly, which may be related to their lifestyle changes, such as reduced daily activities.
(2) childbirth: the number of births, age at first birth, mode of delivery, size of the fetus and the incidence of incontinence during pregnancy are significantly correlated with the occurrence of postpartum incontinence, and the number of births is positively correlated with the occurrence of incontinence; the age at first birth is higher in women between 20 and 34 years of age, and the occurrence of incontinence is more correlated with childbirth than in other age groups; the incidence of incontinence is higher in those who are too old for childbirth Women who deliver vaginally are more likely to have incontinence than women who deliver by cesarean section; women who deliver by cesarean section are at greater risk of incontinence than women who have not given birth; the use of forceps, suction devices, and contractions to speed up labor and delivery also increases the likelihood of incontinence; mothers of large fetuses are also at greater risk of incontinence.
(3) Pelvic organ prolapse: pelvic organ prolapse (POP) and stress urinary incontinence seriously affect the health and quality of life of middle-aged and older women. Stress urinary incontinence and pelvic organ prolapse are closely related, and both are often present together. The thinning and disorganization of smooth muscle fibers, connective tissue fibrosis and muscle fiber atrophy in the pelvic floor support tissue of patients with pelvic organ prolapse may be associated with the development of stress urinary incontinence.
(4) Obesity: obese women have a significantly higher chance of stress urinary incontinence, and weight loss may reduce the incidence of urinary incontinence.
(5) Race and genetic factors: genetic factors have a clear correlation with stress urinary incontinence. The prevalence of patients with stress incontinence is significantly correlated with the prevalence of their immediate family members. The prevalence of urinary incontinence is higher in white women than in blacks.
2. Possible associated risk factors
(1) Estrogen: Declining estrogen has long been thought to be associated with female stress urinary incontinence, and clinical treatment with estrogen has been advocated. However, recent data have questioned the role of estrogen, arguing that there is no correlation between changes in estrogen levels and the prevalence of stress urinary incontinence. It has even been suggested that estrogen replacement therapy may aggravate urinary incontinence symptoms.
(2) Hysterectomy: If stress urinary incontinence occurs after hysterectomy, it is usually six months to one year postoperatively. Surgical technique and the extent of surgical resection may have a relationship with the occurrence of urinary incontinence. However, there is not enough evidence-based medical evidence to confirm a definite correlation between hysterectomy and the occurrence of stress urinary incontinence.
(3) Smoking: The correlation between smoking and the occurrence of stress urinary incontinence is controversial. Some data suggest that urinary incontinence occurs at a higher rate in smokers than in nonsmokers and may be related to smoking-induced chronic cough and decreased collagen fiber synthesis. There are also data that smoking is not associated with the occurrence of urinary incontinence.
(4) Physical activity: High-intensity physical exercise may induce or aggravate urinary incontinence, but there is a lack of sufficient evidence-based medical evidence. Other possible associated factors are constipation, bowel dysfunction, caffeine intake, and chronic cough.
Pathophysiological mechanisms
1, bladder neck and proximal urethra downward shift Under normal circumstances, while the increase in abdominal pressure causes an increase in bladder pressure, abdominal pressure can be transmitted to the urethra at the same time, increasing the ability of the urethra to close in order to prevent the occurrence of stress incontinence. Various causes cause pelvic floor muscles and connective tissue degeneration, damage and weakness, resulting in bladder neck and proximal urethra downward shift, urethral relaxation, functional urethra shortening, increased abdominal pressure is transmitted only to the bladder and less to the urethra, so that the urethral pressure can not be synchronized, thus causing urinary incontinence.
2, the urethral mucosa closure function is reduced normal urethral mucosal folds have the role of sealing pad, can stop the leakage of urine. With the growth of age and other factors, the urethral mucosa atrophy thinning, elasticity decline, can lead to its closure function is reduced. Urethritis and urethral injury causes extensive damage to the urethral mucosa, resulting in mucosal fibrosis, which can also make the closed function of the urethral mucosa diminish or disappear.
3, decreased function of the intrinsic urethral sphincter Urethral smooth muscle, urethral transverse muscle, and periurethral transverse muscle function degeneration and damage, resulting in decreased urethral closure pressure.
4, the dysfunction of the nervous system that governs the structure of the urinary control tissues, the structure and function of the urethra itself, and the neurological dysfunction associated with the supporting tissues around the urethra can lead to urethral closure insufficiency and incontinence. Most closely related are the anatomical location of the proximal urethra of the bladder neck, the function of the intrinsic urethral sphincter and the function of the pelvic floor muscles. However, it is often difficult to distinguish exactly which factor or factors are involved in a particular case, and it is often the result of a combination of several factors.
Symptoms and signs
The goal of the diagnosis of stress incontinence is to confirm that the incontinence is caused by increased abdominal pressure.
1. Take a medical history: understand the various causes associated with stress incontinence, such as childbirth, trauma, pelvic surgery, etc. Understand the impact of urinary incontinence on the patient’s life. It is also important to know whether there are symptoms of difficulty in urination and whether there is overactivity of the forced urinary muscles.
2. Symptoms Urine leaks out of the urethra involuntarily when coughing, laughing, sneezing, or lifting heavy objects. It can be clinically divided into three degrees: degree I: urinary incontinence when coughing, sneezing, lifting heavy objects and other abdominal pressure increases; degree II: urinary incontinence when standing or walking; degree III: urinary incontinence in both upright or lying positions.
3.Physical examination.
① Measure urethral length: insert a balloon catheter, inject 20ml of water into the balloon, gently pull to the inner urethral opening, and calculate the urethral length. The normal length of female urethra is 4cm
If the urethra length is shortened in the standing position or shortened in both standing and lying positions, there is a possibility of stress urinary incontinence.
②Bladder neck lift test: the patient takes a truncated position, increases abdominal pressure when the bladder is full, and urine flows out; at this time, the index finger and middle finger are inserted into the vagina, and the urethra is lifted upward on both sides of the bladder neck, which is positive if the urine flow is aborted.
③Swab test: used to determine the degree of urethral prolapse. A swab is inserted into the urethra after routine sterilization in the truncated bladder position. The angle of swab activity should not be >30° in normal individuals in both stressed and unstressed states, if >30° it indicates weak bladder and urethral supporting tissues.
Diagnostic tests
Diagnosis: Diagnostic criteria for stress urinary incontinence.
1, normal urinalysis and negative urine culture.
2, Normal nerve examination.
3, Weak anatomical support (swab test, x-ray or urethroscopy).
4, Confirmation of overflowing urine under pressure (pressure test or cotton pad test).
5. Normal intravesical manometry map or urethral intravesical pressure (normal residual urine volume, normal bladder volume and sensation; no involuntary detrusor contraction).
Other ancillary tests.
1, urodynamic examination of the normal reflex of the forceps urinaryis muscle, the maximum urinary flow rate increases significantly in stress incontinence, the intravesical pressure decreases significantly during the voiding period, the intravesical pressure is 5.9-7.8 kPa in mild cases, 2.5-5.9 kPa in moderate cases, and below 1.96 kPa in severe cases. urethral pressure decreases, the maximum urethral pressure decreases significantly, and its urethral closure pressure decreases after shifting from the prone to the standing position.
2.Leakage point pressure (LPP) is measured by putting the manometry tube into the bladder and filling the bladder, and recording the pressure in the bladder when urethral leakage occurs, and this pressure is the leakage point pressure. Most of the mild cases are higher than 11.8kPa and most of the severe cases are lower than 5.88kPa.
3, Maximum functional bladder capacity and residual urine measurement are normal.
4.Urethral cystography The normal posterior bladder angle should be 90° to 100°, with the upper urethral axis and the vertical line in the upright position, forming an inclined angle of about 30° of the urethra, and the bladder neck above the lower border of the pubic symphysis. In stress incontinence, the posterior urethral angle of the bladder disappears, the bladder neck is lower than the lower edge of the pubic symphysis, the urethral tilt angle increases, the bladder neck is funnel-shaped and sags, and the urethral axis undergoes different degrees of downward and backward rotation. green divides it into two types: type I, the urethral axis is normal, but the posterior urethral bladder angle increases; type II, the posterior urethral angle of the bladder disappears, and the urethral tilt angle is increased when the abdominal pressure increases and the urethra drops and twists increased, urethral tilt angle >45°, sometimes >90°, weak bladder neck related support tissue, severe symptoms and difficult treatment. McGurie has since proposed naming stress urinary incontinence associated with decreased function of the intrinsic urethral sphincter as type III.
Treatment options
1.Non-surgical treatment
(1) Pelvic floor muscle training: contract the anal sphincter, vaginal sphincter and urethral sphincter in the correct way to strengthen the pelvic floor muscle tone and reduce the degree of downward displacement of the urinary bladder. Method: Contract the anus 10 to 20 times every half hour for more than 3s each time.
(2) Acupuncture or electrical stimulation: Acupuncture points such as Guan Yuan, Qi Hai, Sanyinjiao, and Feet San Li, etc., 1 to 2 points each time, or electrical stimulation of the pelvic floor muscles through anal electrodes or vaginal electrodes to achieve therapeutic purposes.
(3) Drug treatment.
①Drugs to inhibit contraction of the detrusor muscle: tolterodine 2mg, 2 times/d; flavone permethrin 200mg, 3 times/d.
② drugs to increase urethral resistance: ephedrine (ephedrine) 25-50mg, 4 times/d; propranolol 10-20mg, 3 times/d.
(4) Transurethral submucosal injection therapy: Teflon Teflon cream, collagen, biogel or autologous fat tissue are used to inject into the submucosa and muscle layer of the posterior urethra or bladder neck to narrow and elongate the urethral cavity, while playing the role of closing the inner urethral opening. This method is suitable for stress urinary incontinence caused by the dysfunction of the internal urethral sphincter.
2.Surgical treatment
(1) Anterior vaginal wall repair: A longitudinal incision is made from the lower edge of the urethra 1 cm to the bladder neck. The two sides of the vaginal wall are separated and the soft tissues on both sides of the bladder neck and urethra are folded and sutured with a circular needle and silk thread to strengthen the posterior wall of the bladder and urethra. This procedure is indicated for patients with mild symptoms who require simultaneous repair of anterior vaginal wall bulge or hysterectomy.
(2) Posterior pubic bladder neck urethral suspension: A median incision is made in the lower abdomen and the posterior pubic bladder, bladder neck and part of the urethra are fully freed. The tissue around the urethra is sutured to the posterior pubic fascia or suprapubic ligament to lift the bladder neck and urethra and achieve suspension. In recent years, the laparoscopic technique is mostly used abroad for this procedure, which is also called Burch vaginal wall suspension.
(3) Bladder neck or urethral sling: Through a combined ventral-vaginal incision, an autologous biological fascia (such as anterior rectus abdominis tendon, broad fascia, etc.) or artificial material (such as TVT, prolenemesh, etc.) is wrapped around the urethra or bladder neck and suspended and fixed on the muscles and fascia of the lower abdominal wall to compress the urethra and bladder neck and enhance urethral closure. This procedure is suitable for patients with all types of stress urinary incontinence and is currently recognized as one of the procedures with the best long-term outcome.
(4) Endoscopic bladder neck suspension (Stamey procedure, also known as long needle bladder neck suspension): A small incision of 1 cm is made at the upper edge of the pubic symphysis at a point 3 cm from the midline, through which a special long needle is inserted, guided by the index finger inside the vagina, through the vaginal wall at the bladder neck-urethral junction, and a No. 2 nylon thread is led through the small hole in the needle. In the same way, a long needle is inserted parallel to the aforementioned nylon thread and the other end of the thread is led out. The same procedure is performed on the opposite side. The nylon thread is lifted on both sides to restore the posterior angle of the vesicourethra, and a knot is tied outside the rectus abdominis sheath. This procedure is shallow, minimally invasive, safe, accurate and reliable, and is suitable for most women with stress urinary incontinence, especially for obese women and those who have failed surgery. However, the long-term outcome is less favorable.
Edit this paragraph Prevention and prognosis
Prognosis: As the population ages and medical care improves, people’s demands for quality of life increase accordingly. Stress urinary incontinence is a medically curable condition. Surgery is considered the standard treatment for stress urinary incontinence. Successful surgery in carefully selected patients can result in a correction rate of 80% to 90%. In patients who improve with medication or when the success of standard surgery is unlikely, a modification of surgery will achieve a higher success rate.