Modern possibilities for the prevention of pelvic organ prolapse

Introduction

Nowadays, pelvic organ prolapse (POT) is one of the most pressing problems in modern gynecology. The prevalence of POT varies from 2 to 77% among the female population and has no tendency to decrease. The POT forecasts are also disappointing: it is expected that by 2030, 63 million women will suffer from POT [1–4]. An increase in the life expectancy of the population will inevitably lead to an increase in the prevalence of POT.

This review is devoted to the causes and methods of POT prevention at the present stage. Therefore, methods such as pelvic floor muscle training (PFMT), including biofeedback with the use of vaginal simulators, electric pulse stimulation, high-intensity focused electromagnetic stimulation, and non-ablative laser therapy Er:YAG, are considered. A systematic academic literature search was conducted by means of the databases such as Scopus, Web of Science, MedLine, PubMed, and eLibrary.

Perineology was separated into a separate branch about two decades ago. At the moment, huge funds are being invested in its development: specialized centers and perineological holdings are being created, many conferences are devoted to the fight against POT, but the problem has not been completely solved. Surgical interventions in POT cases take the third place in the structure of all the gynecological surgeries performed. Pelvic floor surgery also continues to develop actively, offering more than 300 types of surgical interventions, from “classical” plastic surgery with own tissues to correction by means of using modern synthetic prostheses. Such a huge number of techniques is due to the fact that the intervention does not always provide the expected result for both the doctor and the patient. The number of relapses after plastic surgery with patients’ own tissues reaches 40% [2]. POT correction by means of polypropylene meshes, despite the obvious advantages, also has disadvantages: erosion of the vaginal mucosa, urethro-vaginal fistulas, wrinkling and separation of the prosthesis, chronic pain syndrome, infection and extrusion of nets complicate not only the patient’s but also the doctor’s life. Repeated surgical interventions are associated with technical difficulties and a great risk to the patient's health. Very often, even after successful operations, patients experience psychological difficulties, a sense of inferiority, and fear of resuming the disease [3].

The causes of prolapse relapses are palliative operations (for example, Kocher uterine ventrofixation), surgeries with shortening of the uterine suspension apparatus, disparity of anatomical structures, underestimation of risk factors, violation of surgical intervention technology, and inadequate choice of the volume of surgery [4]. Functional dissatisfaction after surgery is largely explained by the multifaceted pathogenesis of POT. Therefore, an important component in the planning of treatment is the psychological preparation of the patient, the correct definition of the purpose of surgical correction, and an explanation of the need for lifestyle modification to preserve the result and prevent relapse [5].

According to a number of authors, POT starts developing at a young age, gradually progresses, and reduces the quality of life of patients, often leading to destructive changes. However, some researchers believe that POT is not always a unidirectional process and can regress [6]. The duration of the latent period of the disease is estimated to be up to 40 years or more. Often, the disease is diagnosed at late stages, when surgical treatment becomes the only solution. This is due to several factors: clinical manifestations of prolapse cause embarrassment and a sense of shame in patients, and therefore they turn to the doctor late when many areas of life are already suffering. In addition, insufficient knowledge by primary care physicians of the features of the course of this pathology also leads to untimely assistance [7].

The main trend in the treatment of patients suffering from POT is surgical intervention in a specialized center, in the case if prolapse may significantly worsen the quality of the patient’s life. At the same time, the question of management tactics in the early stages of the disease, as well as prevention and modern diagnosis of POT, remains open. Many authors recommend switching to surgical treatment only if conservative methods, such as physical exercises and physiotherapy, are ineffective [8].

Clinical manifestations

Prolapse detection at the initial stages of the disease is important for the outcome and prognosis. In most cases, women report complaints of repeated whiteness, dyspareunia, “squelching sounds” during sexual contact, urinary incontinence under tension, air entering the vagina during exercise (aerovaginism), intermittent stream of urine or its splashing during urination, recurrent vaginitis [9]. It is worth noting that the violation of the vaginal microflora is a risk factor for perineal injury in childbirth, which subsequently leads to insufficiency of the pelvic floor muscles, violation of anatomical and topographic relationships of the vaginal walls with the subsequent development of vaginitis. In the later stages of POT, there is a variety of clinical manifestations, such as a feeling of a foreign body, difficulty urinating, urinary incontinence, constipation, dyssinergic defecation, incontinence of gases and feces, pelvic pain, proctalgia, and lower back pain. They lead to maladaptation, affect the mental health of women, and determine the social significance of this disease [10, 11].

There are a number of simple functional tests for the diagnosis of the early stages of POT, which can be performed at the outpatient stage during the initial treatment of the patient: Valsalva test, cough test, assessment of the strength of the pelvic floor muscles according to the Oxford scale. A perineometer (also called a “vaginal pressure gauge”) is designed to record the force of contraction of the pelvic floor muscles and can be used not only to objectively assess the strength of the pelvic floor muscles but also to monitor the correctness of contractions during PFMT. Special video equipment “Endocamera” has also been developed for visual evaluation of the pelvic floor muscles, but transperineal ultrasound in 3D mode is considered to be the most informative for the diagnosis of the early POT stages [12].

Risk factors

For the rational selection of preventive measures, it is recommended to allocate a risk group of patients for the development of POT. The structural features of the pelvic floor in women themselves contribute to the formation of prolapse, but this disease does not occur in all the patients. Based on the analysis of literature sources, the following risk factors for POT can be identified: menopause, repeated pregnancies and childbirth, especially with polyhydramnios, multiple births, operative vaginal delivery, fetal macrosomia, conditions accompanied by a chronic increase in intra-abdominal pressure (constipation, chronic bronchitis, COPD, obesity), hypoestrogenism, metabolic syndrome, hyperthyroidism, violation of innervation and circulation of the pelvic floor, genetic predisposition, interventions on the pelvic floor, including injuries, hysterectomy, as well as unfavorable social conditions. Also, there is data that abortions, uterine fibroids, polyps, neoplasms, as well as cystitis, can be the cause of a decrease in pelvic floor muscle tone. While studying the anamnesis of patients, it was found that 80% of them reported hard physical labor, and 60% lived in rural areas. In athletes, the cross-sectional area of the pelvic floor muscles is larger, but also the area of the levator opening is larger. There are a number of studies proving that intense physical activity can cause and exacerbate POT, but the data are contradictory. According to the academic literature, the incidence of vaginal vault prolapse after a hysterectomy is about 43%. However, there is evidence that there is no statistically significant association between the recurrence of prolapse and the presence of a history of hysterectomy, as well as diseases accompanied by increased intra-abdominal pressure [13][14].

Many researchers emphasize the role of connective tissue dysplasia (CTD) in the POT pathogenesis in 78.8–98.3% of patients [15]. The clinical course of prolapse in CTD is characterized by the early onset (34.2±9.04 years), the rapid development of stages requiring surgical correction after the first physiological delivery in 32% of patients, and predominance of apical forms of prolapse [16]. The pathogenesis of the disease is explained by the presence of a defect in the structure of collagen fibers, which leads to a change in the architectonics of the muscles and ligaments of the pelvic floor and, as a consequence, to the development of prolapse. The presence of CTD causes a POT relapse in the postoperative period. However, a number of authors claim that the prevalence of true CTD cannot exceed 1%.

An important risk factor for the development of POT is perineal ruptures during childbirth and episiotomy. Turning to anatomy, it is worth pointing out that the pelvic floor is a domed muscle layer facing upwards and contracting in response to an increase in intra-abdominal pressure. The so-called trampoline reflex trains the pelvic floor muscles during daily physical activity. However, this mechanism is active only under the condition of the integrity of the pelvic floor muscle fibers, because if the integrity is violated, the contraction vectors will stretch them in opposite directions and thereby increase the damage, questioning the safety of PFMT in case of injury to the perineal muscles. Studies show that an episiotomy in 80% goes into a further rupture along the angle of the wound and in 70% after an episiotomy, undiagnosed perineal injuries are detected. Consequently, one of the main methods of preventing POT is the restriction of perineo-episiotomies [17].

Pelvic floor dysfunction is a complex of disorders of the function of the ligamentous apparatus and musculature of the pelvic floor, which holds the pelvic organs in a normal position and ensures the retention of urine and feces.

Signs of pelvic floor dysfunction are noted during pregnancy, progress, and persist for at least 6–8 weeks in the postpartum period [18]. However, the symptom of vaginal protrusion, which is noted by many patients, is not associated with anatomical prolapse during pregnancy and within 6 weeks after childbirth [19]. During pregnancy and childbirth through the natural birth canal, the load on the pelvic floor muscles contributes to their stretching several times. Such changes are accompanied by the rupture of individual muscle fibers; therefore, even physiological childbirth is a risk factor for pelvic floor dysfunction. Latent perineal injuries are noted in 8.1% of first-born and 22.8% of repeat-born patients. The process of damage to the pelvic floor begins with the rupture of the vagina, then passing to the fascia and muscle layer, and only then, the posterior spike and the skin of the perineum are damaged, which explains the presence of pelvic floor dysfunction after seemingly physiological childbirth. It is shown that the force of contractions of the pelvic floor muscles does not recover within 8 months after delivery to the indicators recorded before pregnancy. This problem is aggravated by the presence of birth injuries, the anatomically and clinically narrow pelvis, as well as a small interval between pregnancies. Therefore, a number of authors recommend pregnancy planning no earlier than one year after natural childbirth and 2 years after cesarean section [20].

Prevention of pelvic floor dysfunction

Postpartum rehabilitation is a complex of therapeutic and preventive measures aimed at restoring the physical and psychological health of patients in the postpartum period. While developing a rehabilitation program, it is necessary to take into account that manifestations of pelvic floor dysfunction are often found in patients in the postpartum period. This puts the need for the use of methods aimed at preventing POT. Most patients in the postpartum period seek to restore their figure, starting with abdominal muscle training. These exercises, leading to an increase in intra-abdominal pressure, increase the load on the relaxed muscles of the pelvic floor and contribute to the progression of pelvic floor dysfunction.

Humankind has been practicing PFMT for a long time. Previously, improvised means were used for them, for example, stone and wooden eggs. In 1948, Arnold Kegel first described exercises aimed at strengthening the pelvic floor muscles, which remain relevant to the present. However, to date, there are no clinical recommendations defining the range of patients to whom these exercises can be recommended, specific schemes and a convincing evidence base. Also, most of the available studies do not provide enough detailed information about the execution technique to apply them in practice [21].

A comparative study of the use of PFMT and pessaries in the postpartum period in women with risk factors for POT, presented by Sukhanov et al., showed the overall 95.6% effectiveness of these techniques, while PFMT (Kegel exercises) were more effective, significantly increasing the tone of pelvic floor muscles compared with gynecological pessaries. The mechanism of action of pessaries is explained by a decrease in the pressure of internal organs on the relaxed muscles of the pelvic floor, contributing to its strengthening and relief of symptoms of POT. In addition, the authors recommend training PFMT under the supervision of a specialist using a device in the biofeedback mode, followed by a transition to independent training with portable devices, for example, the iEASE XFT-0010 perineometer [22].

A study of the comparative effectiveness of using the Yolana Phase 1 vaginal simulator in patients with grade 1 prolapse and overt or latent urinary incontinence showed that training using this device turned out to be more effective than Kegel exercises in terms of pelvic floor muscle strength; therefore, subjective assessment of symptoms of stress urinary incontinence (SUI) and the degree of prolapse. Moreover, in patients who performed Kegel exercises, after 6 months of training, the degree of prolapse increased [23]. The EmbaGYN device stimulates the pelvic floor muscles through exposure to the n. pudendus branches and promotes increased blood flow in the adjacent deep tissues, which is necessary for patients with a marked decrease in muscle tone. “Blind” exercise may be ineffective due to the fact that the patient may misunderstand which muscles need to be contracted. The use of simulators makes it possible not only to control the correctness of training but also to record the result. Thus, the use of simulators is a promising method of prevention and treatment of pelvic floor dysfunction.

Biofeedback therapy demonstrates good results in the treatment of prenatal and postpartum insufficiency of the pelvic floor muscles and also reduces the frequency of SUI after childbirth [24]. According to Liu et al. (2020), PFMT using the biofeedback method statistically significantly reduces the severity of symptoms of overactive bladder, SUI, and the stage of prolapse [25]. In addition, biofeedback therapy proved to be effective in the treatment of dysfunctional urination, including when combined with exercises with extracorporeal electromagnetic stimulation [26].

A systematic review of 21 sources highlights the effectiveness of combining PFMT with electromyography (EMG) biofeedback compared to PFMT alone in relation to symptoms of SUI, quality of sexual life, and strength of pelvic floor muscles [27]. However, the multicenter randomized controlled clinical trial presented by Hagen et al. did not reveal a difference between PFMT under EMG control and only PFMT after 24 months with a stressful or mixed form of urinary incontinence, and therefore the authors do not recommend routine use of this method [28]. At the same time, research by Yaschuk et al. on the use of PFMT by the biofeedback method on the Vagiton pneumo simulator 2 months after delivery showed a statistically significant increase in the strength of pelvic floor muscle contractions after 10 workouts and the preservation of these changes in dynamics after 6 months, including in patients with a history of episiotomy. It is emphasized that it is the biofeedback method that increases the patient's adherence to treatment [29].

The results of the meta-analysis by Romero-Franco et al. (2021) demonstrated that most exercises for PFMT improved the condition of the pelvic floor muscles, reduced the manifestations of POT, and improved the quality of life of patients, but the small sample sizes in the studies do not allow drawing unambiguous conclusions [30].

An effective method is electrostimulation of the pelvic floor muscles with a decrease in their tone after childbirth. Some authors recommend combining training with electrical stimulation in the presence of symptoms of SUI [31]. The results of the meta-analysis conducted by Zhu et al. (2021) showed that PFMT in combination with electrostimulation improved urodynamic parameters, increased the strength of the pelvic floor muscles, and, in general, proved to be more effective and safer against early postpartum symptoms of SUI than PFMT alone [32]. According to the Cochrane Review of 2017, electrostimulation is effective in the treatment of SUI; however, the studies studied had a low-quality evidence base to draw unambiguous conclusions [33].

The combined use of biofeedback therapy and electro-pulse stimulation of the neuromuscular apparatus in patients with stage I–II prolapse leads to a significant reduction in the symptoms of prolapse and their impact on the quality of life after 1 year of follow-up compared with lifestyle modification. A decrease in the symptoms of POT was noted in 62.5%, and the transformation of stage II into stage I in 37.5% of the subjects; the same trend persisted among patients with stage III–IV prolapse after surgical treatment [34].

There is a hypothesis that the use of physiotherapy in the treatment and prevention of pelvic floor dysfunction, provided a well-off fascia, will significantly improve the quality of life and sexual function of patients. It has been proven that high-intensity focused electromagnetic stimulation (HIFEM) leads to muscle contractions significantly exceeding conscious ones in strength. In patients with pelvic floor muscle dysfunction who underwent HIFEM therapy, there was a decrease in the anterior-posterior size of the levator opening more than in the group of abdominal electrical stimulation of the pelvic floor muscles, a decrease in the number of points according to the results of the PFDI-20 questionnaire, and the preservation of the result obtained after 6 months. Consequently, electromagnetic therapy has a longer duration of effectiveness, which makes it possible to recommend it for the prevention of the development of POT and improvement of the treatment outcomes of the existing disease [35].

Vaginal relaxation syndrome

Vaginal relaxation syndrome (VRS) occurs in 24–38% of women [36]. VRS is a feeling of lack of tone, or looseness, of the vagina caused by an overextension of levators. The area of the levator diaphragm at the maximum level of the Valsalva test, apparently, is a measure of the extensibility of the muscle that raises the anus, and the most characteristic symptom of VRS [37]. It is believed that VRS is an early symptom of POT, but there are conflicting data [38]. The main manifestation of VRS is a violation of sexual function [39]. So, 1 month after childbirth, PFMT by means of using a portable device for electromyostimulation in combination with a course of radio wave exposure with Surgitron S5 (Pelleve technology) improved local blood circulation and increased pelvic floor muscle strength on the Oxford scale (compared with the patients from the control group who did not receive any treatment). The patients also noted the elimination of sexual dysfunction, a decrease in the entrance to the vagina, and a decrease in the symptoms of pelvic floor dysfunction [40].

The results of several multicenter randomized controlled clinical trials have shown the effectiveness of non-ablative laser therapy Er:YAG in VRS treatment. After the course of therapy, the patients noted an improvement in the tightness of the entrance, visual data, and improved sexual satisfaction. The strength of pelvic floor muscle contractions after treatment was also higher than in the placebo group [41, 42]. Non-ablative laser therapy Er:YAG also reduces the symptoms of SUI and improves the quality of life and sexual function in premenopausal women who gave birth significantly better than placebo. After 3 months, 21% of the treated patients noted a decrease in urinary incontinence symptoms compared to 4% of the placebo group patients. All the parameters of perineometry improved after the treatment, and the strength of pelvic floor muscle contractions increased statistically significantly compared to the placebo group [43].

Postmenopause prevention

The tone of the pelvic floor muscles in the menopausal period is an important factor in the sexual health of postmenopausal patients. Postmenopausal women with pelvic floor muscle dysfunction have lower sexual activity than women without signs of POT. It is emphasized that patients with well-to-do musculature are more likely to use menopausal hormone therapy (by 39.2%), which apparently reduces the effect of hypoestrogenism [44]. A number of studies show that PFMT is effective not only in relieving symptoms of pelvic floor dysfunction but also in treating mild forms of POT [45–48]. Data from a multicenter randomized controlled clinical trial involving 414 patients confirms the effectiveness of PFMT compared with lifestyle modification for secondary prevention of POT [49].

According to Alves et al. (2015), PFMT proved to be effective in postmenopausal women, led to an increase in the contractility of the pelvic floor muscles according to surface EMG data and a decrease in urinary symptoms. Group classes have additional benefits, both for patients, contributing to increased motivation, and for the healthcare system [50].

The analysis of literature sources has shown that much attention is paid to the study of methods for correcting symptoms of urinary incontinence, while manifestations of dysfunction of the lower gastrointestinal tract, which significantly worsen the quality of life of patients, fade into the background. A systematic review in 2021 devoted to the prevention and treatment of fecal incontinence shows that PFMT, biofeedback, and electrostimulation can be recommended for this group of patients, as they increase the tone and endurance of the pelvic floor muscles, as well as improve neuromuscular conduction [51].

The experts of the British Royal Society of Obstetricians and Gynecologists recommend the following rules of lifestyle modification to prevent the development and progression of POT [52]: quitting smoking, treatment of diseases accompanied by chronic cough; normalization of stool; restriction of physical exertion with lifting weights; weight control with maintaining normal BMI; PFMT.

Alternative workouts, such as Pilates, tai chi, etc., are not recommended for the prevention of POT. The abdominal hypopressive technique developed in the 1980s, based on the hypothesis of reflex activation of the pelvic floor muscles in response to reduced intra-abdominal pressure, also has no evidence base to recommend it to patients [53][54].

It should be noted that the introduction into routine practice of methods of POT prevention, in particular, PFMT, is difficult due to the lack of appropriate staff of specialists who know these techniques and the necessary technical support. Training of clinicians on the anatomy and physiology of the pelvic floor, methods of prevention of prolapse, as well as educational work with the population, are important stages in the fight against this disease [55][56]. A survey of patients who performed PFMT at home after training with a specialist showed that adherence to exercise depended on the training program, its effectiveness, their personal experience and beliefs, as well as the availability of feedback. It can be concluded that the exercises should be simple enough to implement them into everyday life, effective, and controlled. Raising awareness of the need to treat pelvic floor dysfunction will also encourage patients to stick to training [57].

Conclusion

The development of measures to prevent pelvic floor dysfunction is an important area of medical development. Despite the large number of available techniques, further studies of their effectiveness are required. At the same time, the reserves include not only training personnel but also informing the patients themselves about pelvic floor dysfunction, its manifestation, and methods of correction, as well as the need to comply with the recommendations.