Stress urinary incontinence in women 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 the increase in age, the incidence increases, the symptoms worsen, which seriously affects the quality of life of patients. With the increase in human life expectancy and the demand for quality of life, stress incontinence is gaining attention.
Quality of life is a new modern medical concept, which is generally recognized by clinicians, and more and more doctors recognize that the efficacy of incontinence treatment is based not only on the improvement of objective symptoms, but also on subjective feelings. Currently, incontinence symptomatology and diagnosis and treatment emphasize and pay great attention to the quality of life of patients, the effect of treatment depends more on the subjective evaluation rather than objective evaluation, and the evaluation of quality of life is related to social status, cultural background, ideology, life norms, the impact on the life of a person is also different. This requires doctors to care for patients’ quality of life in treatment with a humanistic mindset, to develop treatment plans, and to improve the overall effect of treatment.
(i) Definition.
International Continence Society (ICS) definition: It is the involuntary overflow of urine from the external orifice of the urethra 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 urine leakage under normal conditions, but automatic urine flow when abdominal pressure is suddenly increased.
(II) Clinical epidemiology
1. Prevalence
The prevalence varies, generally between 23% and 45%, with severe incontinence in 3% to 10%, about half being stress incontinence and the rest being urge incontinence and mixed incontinence.
Foreign reports 41.6% to 81%, the United States about 15% to 60%, domestic reports about 40%,
Among women aged 40 years and above, stress urinary incontinence increases by 10% for every 10 years of age, reaching 61.54% for women aged 60 years and above.
2, the more clearly related factors
(1) Age
Age is generally considered to be associated with the prevalence of stress urinary incontinence, which increases with age,
Minassian et al. suggested that the peak age of onset of SUI is 45-55 years,
Reasons: ( 1) With increasing age, degenerative changes occur in organs, bladder capacity gradually decreases, bladder forced urinary muscle elasticity and contractility decreases, resulting in increased bladder instability compared to younger age.
(2) As the body ages, the tissues around the urethra and pelvic floor atrophy and the function of these atrophied tissues in maintaining urethral pressure and supporting the bladder diminish significantly.
(3) After menopause, estrogen secretion decreases and the synthesis of collagen fibers, which are the main component of the pelvic floor support tissue, decreases, leading to a weakening of the pelvic floor tissue support force; at the same time, the decrease in estrogen levels also causes the target organs of estrogen action such as the urethral mucosa to atrophy, shortening the length of the urethra, which in turn leads to a decrease in periurethral closing pressure.
(2) Fertility
The prevalence of urinary incontinence is higher during pregnancy than during non-pregnancy. The incidence is about 23% to 67% during pregnancy, 35.6% to 65.1% in late pregnancy, 13.0% to 31.1% in the third trimester, and 22% in the first year after delivery.
Causes.
Changes in hormone levels during pregnancy reduce the collagen fiber content of pelvic floor tissues, weaken the connection, and weaken the supporting force of the tissues around the urethra;
During pregnancy, the weight increases, the uterus enlarges, and the enlarged uterus pushes up the bladder, causing the position of the bladder urethra to rise and the bladder neck to take on a funnel shape, making it easy for urinary incontinence to occur.
When the enlarged pregnant uterus compresses the right iliac vein, which causes impaired blood flow, if it is not relieved for a long time, it can cause ischemia and hypoxia in the pelvic floor tissues and lead to metabolic disorders.
The pressure of the large uterus during pregnancy reduces the bladder capacity and makes urinary urgency and frequency more likely to occur.
The incidence of SU I after cesarean delivery (obstructed labour) is similar to that of spontaneous delivery, and vaginal delivery increases the risk of urinary incontinence in the next pregnancy by 5.7 times, whereas cesarean delivery does not increase the risk of urinary incontinence in the next pregnancy.
However, it should be noted that cesarean delivery can only reduce the incidence of SUI, but not completely prevent postpartum incontinence, because pregnancy itself can also damage the pelvic floor tissues and increase the risk of incontinence, and cesarean delivery has certain risks for the mother and child.
The possible mechanisms of stress urinary incontinence due to transvaginal delivery are:
(1) weakening and stretching of muscles and connective tissues during delivery, resulting in relaxation of the pelvic floor;
(2) Natural laceration during delivery or the need for lateral episiotomy, which results in a change in the position of the pelvic organs due to damage to the supporting tissues;
(iii) Stretching of the pelvic floor during labor can damage the pubic nerves, pelvic nerves, and muscles and connective tissue of the pelvic floor, and may affect the timely contraction of the transverse urethral sphincter in response to increased abdominal pressure.
The number of pregnancies, the number of deliveries and the degree of SUI incontinence are positively correlated, and the incidence of maternal incontinence is 59%, which is significantly higher than that of non-maternal, and the incidence of incontinence tends to increase with the number of deliveries.
④ Age at first birth: the incidence of SUI is higher when the age at birth is too old
⑤ Other obstetric factors Perineal incision, forceps assisted delivery, fetal weight, time to start labor after delivery, etc. are also closely related to the occurrence of SUI.
It is generally believed that due to the large size of a huge baby, it is easy to overstretch the uterus, bladder neck and tissues around the urethra during pregnancy and delivery, and cause prolonged labor, resulting in urinary incontinence.
A short postpartum labor period can aggravate the damage to the pelvic floor that already occurred during pregnancy and delivery, leading to urinary incontinence.
Urinary incontinence is strongly associated with forceps/vacuum suction, lateral episiotomy and perineal suturing
(3) pelvic organ p rolap se (POP)
SUI and POP are strongly correlated, with 50% of patients with POP having SUI and 80% of patients with SUI having POP, and there is a significant positive correlation between the degree of pelvic organ prolapse and 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 in their immediate family. The prevalence of urinary incontinence also varies 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.
(1) Obese patients have higher abdominal pressure than normal people, and the long-term high abdominal pressure state is likely to cause pelvic floor organ prolapse, urethral downward migration, and then stress or mixed incontinence;
② The increased weight of obesity can squeeze down the pelvic floor tissues, so that the muscles, nerves and other structures of the pelvic floor are weakened by long-term stress and strain.
③Increased body mass may increase susceptibility to the development of SU I. Conversely, decreased body mass may decrease susceptibility;
④Obesity may be secondary to increased intravesical pressure and urethral hyperactivity;
(5) Because obese patients tend to have dyslipidemia, blood flow and bladder nerve distribution are also impaired.
Recently, there is evidence that abdominal obesity is more likely to suffer from SUI, waist circumference hip ratio more reflective of overweight and obese people’s body shape differences, and with the high body mass index (BMI) and waist circumference increase, multifactor analysis that waist circumference is a more sensitive risk factor for SUI.
3. Possible associated risk factors
(1) Hysterectomy usually occurs 6-12 months after surgery
Possible mechanisms of urinary incontinence after hysterectomy are:
①Hormonal mechanism (for women, hysterectomy plus oophorectomy is surgical menopause) ;
(ii) damage to the pelvic floor nerves during surgery;
(iii) damage to the musculofascial tissue connecting the bladder to the surrounding pelvic wall.
Epidemiological studies have shown that hysterectomy is associated with urinary incontinence, but this issue is still controversial. Univariate analysis found an increased prevalence of urinary incontinence after transabdominal total hysterectomy, while some scholars suggested no significant association between total hysterectomy and the occurrence of urinary incontinence by multifactorial analysis.
(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 is still controversial.
(3) Disease history
Fritel et al. suggested that diabetes mellitus, diuretic use, urinary tract infection, previous gynecological surgery, constipation, fecal incontinence, perineal sutures, 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.
Lower urinary tract infections Urinary tract infections are also closely related to the occurrence of urinary incontinence, as urinary tract infections increase the sensitivity of the bladder to stimulation, making it prone to urinary urgency, frequency, and in severe cases, urge incontinence. landi et al. concluded that the chance of urinary incontinence with recent urinary tract infections is 3.46 times higher than without urinary tract infections.
Chronic respiratory diseases and constipation Chronic respiratory diseases such as chronic cough, chronic obstructive pulmonary disease and habitual constipation can cause a persistent increase in abdominal pressure and contribute to the development of SU I.
Diabetes mellitus and cardiovascular disease Maggi et al. reported that the risk of urinary incontinence was twice as high in diabetics as in non-diabetics. Urinary incontinence due to hypertension is associated with the frequent use of certain medications in patients with hypertension. These medications tend to cause irritating dry cough and increase abdominal pressure, which in turn leads to urinary incontinence. At the same time, it is also related to high blood pressure that can cause cerebrovascular accidents,
The main causes of urinary incontinence due to cerebrovascular accidents are: (1) the lesion directly disrupts the connection between the higher urinary center and its lower urinary center, resulting in urinary incontinence; (2) complications of stroke, such as aphasia and immobility, lead to inability to urinate in a timely manner; (3) the application of drugs that affect urinary function, such as tricyclic antidepressants and anticholinergic drugs, which tend to cause weakness in urination, secondary urinary retention, filling incontinence, etc. These drugs are likely to cause urinary weakness, secondary urinary retention, filling incontinence, etc. Women with cardiovascular disease are prone to SU I because cardiovascular disease itself and the drugs used to treat these diseases can aggravate the symptoms of urinary incontinence, such as α-adrenergic receptor antagonists can inhibit bladder neck closure and cause SU I. Diuretics can inhibit urine reabsorption and increase urine production by the kidneys, thus aggravating the existing symptoms of urinary incontinence.
(4) Lifestyle
Smoking: It is controversial that the high prevalence of urinary incontinence in smokers may be related to the following factors:
(1) Nicotine in tobacco can stimulate unstable bladder contractions;
②Smoking can interfere with collagen synthesis;
③ smoking causes chronic coughing can increase abdominal pressure and aggravate the onset of urinary incontinence.
Alcohol and coffee consumption have also been reported in the literature to increase the risk of SUI.
Physical exercise also has an effect on the occurrence of SUI. They believe that moderate exercise can make the pelvic floor muscles contract powerfully, which is good for weight loss and reduces the occurrence of cardiovascular diseases, and is a protective factor for the occurrence of SUI, while excessive abdominal pressure in people with high intensity exercise (such as athletes) can cause damage to the pelvic floor tissue and induce SUI.
(5) Diet
Total fat intake (especially saturated fatty acids) is significantly associated with the development of SUI,
Increased cholesterol intake also increases the risk of SUI.
The trace elements zinc and vitamin B12 were positively associated with the development of stress urinary incontinence.
Carbonated beverages are a risk factor for stress urinary incontinence,
Bread reduces the risk of stress incontinence.
Carbohydrate is a protective factor for the development of SUI,
(6) Other Occupation, education, type of residence.
were associated with the occurrence of urinary incontinence. Those engaged in manual labor are susceptible to SU I, which may be related to the increase in abdominal pressure easily caused by prolonged physical labor, with a prevalence of 53.0% for heavy manual labor SU I, 18.0% for housewives, and 15.4% for mental workers. This may be related to the greater proportion of mental labor, fewer births, and stronger health awareness among the highly educated.
(III) Pathophysiological mechanism
1. early theories.
The belief that the normal anatomical position of the bladder neck plays an important role in urinary control, leading to incontinence when the bladder neck position decreases.
2 “hammock” (hammock ) hypothesis: proposed by De Lancey in 1994
The suburethral “hammock” formed by the pubourethral ligament 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 as a result of intra-abdominal pressure on the urethra in the abdominal cavity. Urinary incontinence symptoms occur when the supporting tissues are weak or damaged.
(iv) SUI typing
Two major categories and 3 types.
(1) Increased urethral mobility type: 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 urethral bladder pressure gradient no longer exists, so urinary leakage occurs.
There are two types according to the degree of urethral movement.
Type I: the drop of the urethra and bladder neck is less than 2 cm.
Type II; the descent of the urethra and bladder neck is greater than 2 cm.
(2) Defective internal urethral sphincter type (type III): poor docking of the proximal urethra and bladder neck due to extensive pelvic surgery, urethral surgery or injury or neurological lesion, which is open for a long time and will lead to urinary leakage if abdominal pressure increases.
(V) Progress of SUI treatment principles
Based on the two aforementioned theoretical doctrines, many surgical treatment methods have been developed.
1. Early treatment methods.
The aim is to elevate the bladder neck and restore it to its normal anatomical position, i.e. in the pelvis, but both suffer from recurrence of symptoms and the occurrence of urinary obstruction.
Retropubic bladder neck suspension
Transvaginal bladder neck suspension
Pubovaginal suspension
2. Newer treatment methods.
In contrast, 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) Principle of TVT surgery
”Tension-free mid-urethral suspension”: the Swedish Ulmsten invented a similar rectus abdominis fascia bladder neck suspension procedure in 1996.
(i) The TVT surgical suspension is a polypropylene mesh band made of artificial material, not its own rectus abdominis fascia.
②TVT surgery mimics the anatomical structure of a “hammock” by suspending the mid-urethra (instead of suspending the bladder neck) and tension-free support of the mid-urethra, thus strengthening and improving the function of the pubourethral ligament and at the same time enhancing the “hammocking” effect of the suburethral vaginal wall and its connection with the pubococcygeal muscle. (ii) the connection with the pubococcygeal muscle.
(3) TVT surgery did not elevate the bladder neck, nor did it reduce the mobility of the bladder neck, but only formed a strong support for the urethra, so that the proximal urethra was stabilized and the lower part of the urethra and the functional shape of the pelvic floor did not change when the patient urinated.
④Fibroblasts grow into the mesh band after surgery to strengthen the connective tissue of the middle urethra and prevent stress urinary incontinence.
⑤TVT simplifies the surgical steps, improves the treatment effect and ensures long-term treatment results.
⑥The operation is performed by making three small 1 cm incisions in the vagina and lower abdominal skin, with a short operative time and an efficiency of more than 95%.
(6) Cystoscopy is required to make sure there is no damage to the bladder during the operation.
2) Superiority of TVT-O surgery
Ø medial thigh root “trans-occlusive non-tensile midurethral suspension”: first reported in 2002, the least invasive stress urinary incontinence procedure reported to date
Completely transvaginal and vaginal
The puncture route is not through the posterior pubic space, but through the descending pubic bone branches of both closed holes, which is more in line with the natural anatomy of the pubic urethral ligament
The puncture is further away from the bladder, urethra and posterior pubic space, and the sling is placed in a shorter route
Reduced organ damage and complications such as bleeding and hematoma
Postoperative urethral obstruction and urinary retention are less likely to occur
Intraoperative cystoscopy is not required
Simpler and more convenient than TVT surgery, with shorter operating time, smaller incisions, and virtually invisible scarring after surgery
The safety of the procedure is further improved and support can be formed under the middle part of the urethra
Precautions
Make sure that the sling is placed without tension during the operation
Postoperative attention should be paid to the presence of common complications such as infection, hematoma, urethral compression, difficulty in urination, and instability of the forceps.
Daily activities can be performed after 1 to 2 weeks after surgery
Avoid lifting heavy objects and strenuous exercise for 1 month after surgery
Avoid sexual intercourse for 1 month after surgery
In conclusion, TVT-O is easy to perform, less invasive, and the degree of sling suspension can be adjusted at will, especially without complications of bladder injury. It is undoubtedly the best choice for elderly patients with medical comorbidities.
The suspension material is histocompatible and no rejection reaction has occurred so far, which is worth promoting.