Predictability of the individual clinical outcome of extracorporeal shock wave therapy for cellulite

Abstract

Background: Extracorporeal shock wave therapy has been successfully introduced for the treatment of cellulite in recent years. However, it is still unknown whether the individual clinical outcome of cellulite treatment with extracorporeal shock wave therapy can be predicted by the patient's individual cellulite grade at baseline, individual patient age, body mass index (BMI), weight, and/or height.

Methods: Fourteen Caucasian females with cellulite were enrolled in a prospective, single-center, randomized, open-label Phase II study. The mean (± standard error of the mean) cellulite grade at baseline was 2.5±0.09 and mean BMI was 22.8±1.17. All patients were treated with radial extracorporeal shock waves using the Swiss DolorClast(®) device (Electro Medical Systems, S.A., Nyon, Switzerland). Patients were treated unilaterally with 2 weekly treatments for 4 weeks on a randomly selected side (left or right), totaling eight treatments on the selected side. Treatment was performed at 3.5-4.0 bar, with 15,000 impulses per session applied at 15 Hz. Impulses were homogeneously distributed over the posterior thigh and buttock area (resulting in 7,500 impulses per area). Treatment success was evaluated after the last treatment and 4 weeks later by clinical examination, photographic documentation, contact thermography, and patient satisfaction questionnaires.

Results: The mean cellulite grade improved from 2.5±0.09 at baseline to 1.57±0.18 after the last treatment (ie, mean δ-1 was 0.93 cellulite grades) and 1.68±0.16 at follow-up (ie, mean δ-2 was 0.82 cellulite grades). Compared with baseline, no patient's condition worsened, the treatment was well tolerated, and no unwanted side effects were observed. No statistically significant (ie, P<0.05) correlation was found between individual values for δ-1 and δ-2 and cellulite grade at baseline, BMI, weight, height, or age.

Conclusion: Radial shock wave therapy is a safe and effective treatment option for cellulite. The individual clinical outcome cannot be predicted by the patient's individual cellulite grade at baseline, BMI, weight, height, or age.

Keywords: AWT; EPAT; RSWT; acoustic wave therapy; extracorporeal pulse activation therapy; radial shock wave therapy.

Figures

Figure 1

Principles of radial shock wave technology. Notes: (A) DolorClast® device (Electro Medical Systems SA, Nyon, Switzerland) used in the present study. (B) Power+ hand piece of the Swiss DolorClast device with the 36 mm applicator used in the present study. Compressed air (1) is used to fire a projectile within a guiding tube (2) that strikes a 36 mm diameter metal applicator (3) placed on the skin. The projectile generates stress waves in the applicator that transmit pressure waves noninvasively into tissue. (C) Pressure wave generated with the Swiss DolorClast device, measured at a distance of 1 mm from the applicator (Power+ hand piece, 36 mm applicator, device operated at 4 bar air pressure and 15 Hz impulse frequency as used in the present study). After a delay of approximately 2 μseconds, the pressure wave shows an increase in (positive) pressure (i), followed by a decrease in pressure (ii) with reaching zero at approximately 8 μseconds, a subsequent period of negative pressure (iii) interrupted by a period of positive pressure (iv). (D–O) Cavitation bubbles (black dots) in degassed water generated during the phase of negative pressure of radial shock waves generated with the Power+ hand piece and the 36 mm applicator of the Swiss DolorClast device operated at 4 bar air pressure at 15 Hz (D–I) as used in the present study or at 1 Hz (J–O) either at the center of the applicator (D, E, F, J, K and L) or the edge of the applicator (G, H, I, M, N and O). Note that the arrows point to the center of the applicator. Maximum cavitation is shown in (E, H, K and N). The images shown in (D, G, J and M) were taken approximately 1.5 mseconds before the cavitation maximum, and images shown in (F, I, L and O) were taken approximately 1.5 mseconds after the cavitation maximum. Cavitation lasted for approximately one mseconds. The pictures were taken with a high-speed CCD camera (Photron Ultima APX; Photron, Tokyo, Japan) with a framing rate of 300,000 frames per second and an exposure time of 1/2,700,000 seconds. The scale bar in (O) represents 10 mm. Note that the cavitation field (and thus the pressure field below the applicator) is broader when generating radial shock waves at 15 Hz (D–I) than at 1 Hz (J–O). This phenomenon is observed for many radial shock wave devices (Császár et al, submitted for publication).

Figure 2

Radial shock wave therapy for cellulite. Notes: (A) Application of coupling gel. (B) Treatment with the Power+ hand piece of the Swiss DolorClast® device (Electro Medical Systems, Nyon, Switzerland).

Figure 3

Treatment of two patients (1, 2) with cellulite using radial extracorporeal shock wave therapy. Notes: (A1 and A2) Clinical picture at baseline. (B1 and B2) Contact thermography at baseline. (C1 and C2) Clinical picture 4 weeks after the last treatment (follow-up). (D1 and D2) Contact thermography at follow-up. (A1–D1) A 29-year-old female (body mass index 32.9, weight 84.3 kg, height 160 cm). Radial extracorporeal shock wave therapy performed on the left side improved the cellulite from grade 3 at baseline to grade 1–2 at follow-up (ie, δ-2 was 1.5). Despite this objectively substantial treatment success, the patient’s satisfaction was only 5 on a scale ranging from 0 (maximum dissatisfaction) to 10 (maximum satisfaction). (A2–D2) A 51-year-old female (body mass index 20.8; weight 53.3 kg; height 160 cm). Radial extracorporeal shock wave therapy performed on the right side improved the cellulite from grade 2–3 at baseline to grade 1–1.5 at follow-up (ie, δ-2 was 1.25). This patient was very satisfied with the treatment (9 on a scale ranging from 0 to 10). Patient consent was obtained to publish the above images.

Figure 4

Clinical outcome of radial extracorporeal shock wave therapy for cellulite as a function of the patients’ initial cellulite grade at baseline (A and B), BMI (C and D), weight (E and F), height (G and H) and age (I and J) (calculated as individual difference in cellulite grades either between baseline and after the last treatment [δ-1] or between baseline and at follow-up [δ-2], respectively; the higher δ-1 and δ-2, the better the treatment success). Notes: Each dot represents an individual patient; overlapping data are indicated. The Spearman’s nonparametric rank correlation coefficients (r) and the corresponding P-values are provided in red on top of each panel. Abbreviation: BMI, body mass index.

Figure 5

Clinical outcome of radial extracorporeal shock wave therapy for cellulite as a function of the patients’ pain during the treatment (A and B), the patients’ feeling of comfort during treatment (C and D), and the patients’ satisfaction with treatment (E and F) (calculated as individual difference in cellulite grades either between baseline and after the last treatment [δ-1] or between baseline and at follow-up [δ-2], respectively; the higher δ-1 and δ-2, the better the treatment success). Notes: Each dot represents an individual patient; overlapping data are indicated. Pain was assessed using a visual analog scale ranging from 0 (no pain) to 10 (maximum pain). The feeling of comfort was assessed using a scale ranging from 0 (maximum discomfort) to 10 (maximum comfort), and patients’ satisfaction using a scale ranging from 0 (maximum dissatisfaction) to 10 (maximum satisfaction). The Spearman’s nonparametric rank correlation coefficients (r) and the corresponding P-values are provided in red on top of each panel.

Figure 6

Relationship between the individual difference in cellulite grades between baseline and after the last treatment (δ-1) and between baseline and at follow-up (δ-2) after radial extracorporeal shock wave therapy for cellulite (the higher δ-1 and δ-2, the better the treatment success). Notes: Each dot represents an individual patient; overlapping data are indicated. Red, black, and green dots/asterisks indicate patients whose cellulite grade worsened, remained unchanged, or improved, respectively, during the follow-up period compared with the situation after the last treatment. The Spearman’s nonparametric rank correlation coefficient (r) and the corresponding P-value are provided in red on top of the panel.