Integrated approach towards correction of postpartum tissue changes of anterior abdominal wall using RSL sculpting procedure

The article will discuss the correction of postpartum stretch marks (striae), local fat deposits, cellulite, and diastasis of the rectus abdominis muscle using the RSL sculpting procedure.

During pregnancy, hormonal, immunological and metabolic alterations result in changes that occur in many organs, including the largest one, the skin. These changes are most noticeable in those areas of the skin that are subject to overstretching, particularly on the anterior abdominal wall. Stretch marks are among the most common skin manifestations, occurring in approximately 50-90% of pregnant women. Even in pregnant women with normal body weight, hormonal changes cause metabolic alterations similar to those related to obesity, expressed in weight gain, development of insulin resistance, and chronic inflammation in subcutaneous fat. The mother's body weight increase occurs mainly due to the redistribution of fat with predominant localization in the abdominal region, which remains in this area even after childbirth. Microcirculation dysfunction associated with hypertrophy of subcutaneous fat in the anterior and lateral surfaces of the abdominal wall leads to formation of cellulite. During pregnancy, there is also a significant increase in the uterus size, an increase in intra-abdominal pressure, and an increase in tissue extensibility due to enzymatic and hormonal changes. These physiological changes weaken the anterior abdominal wall and contribute to formation of diastasis recti. Stretch marks, local fat deposits, cellulite, and diastasis of the rectus abdominis muscle do not disappear after childbirth and cause psycho-emotional stress in women stemming from insecurities. All of the above determines interest in the problem of using safe and at the same time effective methods of body correction in early postpartum period. One of those methods is RSL sculpting procedure. The procedure combines vibrocompression with spheres and LED therapy (treatment with red light at a wavelength of 650 nm). Due to several physical factors that were proved to be effective, processes that have a beneficial effect on skin, subcutaneous fat, and muscles are launched in the tissues. Advantages of the procedure include physiological nature, lack of restrictions on contact between the mother and the child during the procedure, possibility of widespread application during lactation due to the absence of a negative effect on the child's body, good compatibility with other therapeutic agents and possibility of using the physical factors in various therapeutic regimens, painlessness, and lack of toxicity and allergic reactions.

Skin changes during pregnancy

Stretch marks are skin atrophy appearing in a form of sunken wavy bands of various diameter, localized mainly in places of the greatest skin stretching. Stretch marks form during pregnancy due to hormonal imbalance ¹.

It is believed that one of the most significant factors in pathogenesis of striae is a decrease in production of collagen and elastin by fibroblasts while they maintain the ability to synthesize metalloproteases (collagenase, elastase) ².

Fibroclasts predominate at the site of striae formation and synthesize enzymes that destroy collagen and elastin – the proteins that maintain skin strength ³. As a result, when the skin is overstretched for one of the reasons mentioned, it causes a rupture, a destruction of dermis reticular layer, while the epidermis remains undamaged. In this case, vessels as well as collagen and elastic fibers are disturbed.

Any tissue damage at the initial stages leads to a migration of macrophages to the injury site under the action of chemoattractants (TGf-β, PDGf, CXCI4, leukotriene B4, and IL-1) released in the area of vascular injury ⁴.

Results of histological studies of the skin in striae area showed that at the initial stage the epidermis was almost unchanged, and the dermis was edematous, with perivascular lymphocytic accumulations indicating the presence of local inflammation ⁵.

Over time, signs of atrophy start appearing in the epidermis in a form of its thinning, and in the dermis in the form of papillae smoothing ⁶.

Disruption of the elastin fibers network makes the skin significantly less elastic. Collagen fibers also undergo changes and are visualized as dense packed areas of collagen bundles located horizontally relative to the skin surface ⁷.

Gradually, the number of cellular elements in the striae area decreases, and it becomes increasingly difficult to achieve a pronounced positive result of the procedures aimed at their correction. Therefore, the earlier measures are taken to correct stretch marks, the more pronounced the result will be ⁸, ⁹.

An interstitial fluid is the most abundant extracellular fluid, with a volume four times greater than that of the circulating blood. The studies of its importance in regulation of bodily functions have only recently begun. For example, it has been proven that the interstitial fluid is involved in local delivery of nutrients and removal of metabolic products.

To date, the mechanical role of the interstitial fluid has been demonstrated in a few studies that have shown that increased movement of the interstitial fluid flow leads to the recruitment of macrophages in situ ¹⁰.

Macrophages attracted to the treated area have a pronounced anti-inflammatory effect and also stimulate fibroblasts thus enhancing their proliferation and collagen synthesis (fig. 1)^10,11.

Figure 1. A. An absence of muscle contraction leads to the cessation of the interstitial fluid movement, resulting in the absence of macrophages in this area and, consequently, the development of an inflammatory reaction and muscle atrophy.

FIGURE 1. B. Positive effect of local cyclic compression on the increase in the interstitial fluid flow, resulting in recruitment of macrophages in situ and reduction of the inflammatory response in tissues and the muscle atrophy

As a result, the skin quality improves. Macrophages and fibroblasts can be considered an associated cellular system that functions during injury and structural restoration of connective tissue ¹².

Based on the understanding of pathophysiological mechanisms of stretch marks formation, it is possible to affect the striae visual appearance by increasing the movement of the interstitial fluid.

Currently, the RSL sculpting procedure is one of the safest and most effective methods of tissue treatment, which is able to generate intramuscular pressure waves with an amplitude equivalent to the amplitude of a moderate muscle contraction, so as to modulate attraction of macrophages to the site of exposure, and, therefore, increase the production of new collagen by fibroblasts.

During the device operation, tissues at the exposure site are subjected to short-term compression, which alternates with relaxation, resulting in acceleration of the movement of the interstitial fluid. The positive outcome of the procedures in reducing the severity of stretch marks is associated not only with the procedure’s effect on the speed of the interstitial fluid movement, but also with light exposure at a wavelength of 650 nm, which, according to numerous studies, also leads to stimulation of fibroblasts and increased production of new collagen (fig. 2) ^13-15.

Thus, the above mechanisms potentiate each other's action.

FIGURE 2. A. A - Before treatment. B - After completion of treatment. Increase in collagen amount in the biopsy after treatment with LED therapy, stained with hematoxylin and eosin.

FIGURE 2. B. A - Before treatment. B - After completion of treatment. Masson trichrome staining for collagen (x 200).

Changes in subcutaneous fat during pregnancy

According to the latest data, pregnancy can be considered a trigger for the future development of metabolic syndrome (MS) ¹⁶–¹⁸. In recent studies, it has been demonstrated that the increase in the volume of adipocytes and the nature of predominant distribution of adipose tissue in the visceral region, including in women with normal body weight, play a leading role in increasing the risk of metabolic disorders (fig. 4) ¹⁹.

As was shown in the study conducted by S.L. Pervykh, the RSL sculpting procedure allows for an efficient correction of the local fat deposits. After a course of 10 RSL sculpting procedures held at an interval of 2–3 days, the average size of adipocytes decreased almost 2-fold (from 123.08 ± 13.60 to 67.14 ± 4.20, p < 0.05) ²⁰.

Microcirculatory disorders are noted along with an increase in adipocytes size in pregnant women due to hormonal changes that persist for some time after childbirth. First, a change in capillaries occurs, leading to the increased capillary pressure and the increase in their permeability, extravasation, and subsequent edema of the interstitium. The fluid begins to linger in the adipose tissue, exacerbating metabolic disorders. At the same time, high-molecular proteins enter the interstitial tissue, which stimulate fibroblasts to increase production of collagen fibers ²¹. Against the background of increasing metabolic dysfunctions, hypoxia and acidosis lead to fibrotic changes in connective tissue structures, which, in turn, exacerbates congestion ^22,23. A vicious pathogenic circle of cellulite formation occurs.

The impact should be directed at all links of pathogenesis for the effective correction of cellulite. It has been proven that there is not only a 2-fold decrease in the average size of an adipocyte in the zone of local vibration and barotherapy, but also vasodilation occurs, blood flow increases, density of the vascular component (lumen of microvasculature vessels) per unit area of the zone significantly increases by 32.5%, and lumen of the vessels, respectively, increases by 23.2%, which indicates not only activation of the functional part of the microvasculature, but also stimulation of both the collateral circulation and the main one ²⁰.

Cyclic mechanical stimulation of the skin leads to an increase in expression of certain dermal epidermal junctions (DEJ) and dermal proteins, resulting in remodeling of extracellular matrix (ECM, matrix) ^24,25. Thus, the procedure leads to a significant decrease in cellulite severity, affecting various parts of its pathogenesis.

Changes in rectus abdominis during pregnancy

Thinning and expansion of the linea alba – diastasis recti abdominis (DRA) – may be noted in the anterior abdominal wall after pregnancy. At the first stage of DRA pathogenesis, an imbalance between factors of aggression (increased intra-abdominal pressure) and protection (tone, elasticity of the anterior abdominal wall) develops.

When the factors of aggression begin to predominate, myofascial deformation occurs, as a result of which muscles, the work of which should normally be combined, begin to oppose each other and move into a biomechanically disadvantageous position. Loss of a functionally advantageous position entails a decrease in muscle tone, up to a complete inability to perform a frame function, and atrophy.

The next stage is pathological distribution of the load on muscles of the back, the spinal column, as a result, hypertonicity of the extensor of the spine develops, and lumbar lordosis is aggravated. As a result, pain syndrome may appear. Functional limitations develop with significant diastasis: inability to lift weights, limited mobility in the lumbar spine, defense attitude due to pain syndrome.

Accordingly, the clinical pattern will vary significantly depending on the severity of myofascial deformity, ranging from minor cosmetic discomfort to a possible decrease in disability. For severe cases, surgery is the only treatment ²⁶,²⁷.

It is generally known that vibration is a physical stressor that causes various neurovegetative and somatic reactions. Vibration exposure with a specially selected frequency and amplitude has been proven to increase the strength of individual muscle groups ²⁸–³⁵. Therefore, the correction of muscle tone using the RSL sculpting procedure is possible in mild forms of DRA, since there is no risk of incarceration or strangulation in diastasis (fig. 1, 3).

FIGURE 3. RSL sculpting at an interval of 2-3 days, started 1 month after natural delivery without complications. A - before the procedure, B - after 10 procedures

FIGURE 4. RSL sculpting at an interval of 2-3 days, started 3 month after natural delivery with complications. A - before the procedure, B - after 9 procedures

Procedure protocol

The procedure can be started as early as one month after natural childbirth (fig. 3) that passed without complications, and 2 months after a caesarean section or childbirth with complications (fig. 4).

The work begins from the back surface of the body in the following order: back, upper limbs, lower limbs; first, lymphatic drainage is performed, followed by deep tissue processing. Then the patient turns over on back, and the front surface of the body is treated in the following order: the abdomen, upper limbs, lower limbs; similarly, the lymphatic drainage stage is performed first, and then the deep tissue processing.

At the stage of lymphatic drainage, a rotation frequency of 150 to 280 rpm is used, going to 200-450 rpm at the stage of deep tissue processing. The pressure level of the handpiece depends on an individual sensitivity of the patient, the depth of treatment, and the zone of influence.

So, at the stage of lymphatic drainage, as well as when working in a high sensitivity area where subcutaneous fat is poorly expressed, the minimum pressure force is applied (one segment of the icon is filled with yellow). When working in areas with soft subcutaneous fat of medium severity and with signs of cellulite, an average degree of pressure on the handpiece is applied (two segments of the icon are filled with yellow).

For deep intensive study in areas where large muscles, dense subcutaneous fat, signs of fibrous cellulite are located, a high degree of pressure is applied (three segments of the icon are filled in yellow).

Use of a sensory pressure control system increases the efficiency of the procedure and allows for a correct and safe distribution of the load on the patient's body. A course includes an average of 10 procedures with a desirable interval of 2–3 days. After the course, it is recommended to carry out maintenance procedures (twice per month). One procedure lasts for 75-90 minutes.