Epidemiological study of 740 areas treated with cryolipolysis for localized fat Estudo epidemiológico de 740 áreas tratadas com criolipólise para gordura localizada

Introdução: A non-invasive alternative for the treatment of localized fat is cryolipolysis that, by freezing adipocytes, reduces fat volume in the region where the procedure was performed. Objective: To statistically describe the experience of a referral center for this procedure. Methods: A cross-sectional study with 251 patients undergoing cryolipolysis was carried out with the epidemiological analysis of patient data. Results: Thirty-eight males and 213 females underwent the procedure, with a total number of 740 treated areas. The anterior abdomen (lower third) was the most popular region, with 45.30% of cases. Eighty-eight percent were satisfied or very satisfied with the result. Nearly all cases required 2 or more sessions to achieve this degree of satisfaction. Conclusions: Cryolipolysis is a noninvasive method for the selective reduction of fat that has shown efficacy in reducing the subcutaneous tissue, with minimal and reversible side effects in this study.

flanks and abdomen). The average age of the study participants was 45 years (min = 13, max = 71).
The patient satisfaction index seen in Graph 2 depicts the following percentages: 25% were very satisfied, 63% satisfied, 10% somewhat satisfied and 2% were unsatisfied. The 3D photographic analysis carried out by the independent observer presented the following distribution: 17% of cases were rated as 1 and 83% were rated as 2.
The minimum number of sessions required to achieve any level of clinical outcome in the body area can be seen in

INTRODUCTION
Liposuction used in the removal of excess localized fat is the most frequently performed surgery in the United States of America. Due to the disadvantages inherent to this surgical procedure, such as the possibility of hospitalization and general anesthesia, complications and time of postoperative recovery, there is a growing demand for non-invasive body esthetical procedures. [1][2][3][4][5][6] A frequently used non-invasive alternative is the cryolipolysis, that reduces fat volume in the region where the procedure was performed through the freezing of adipocytes. Due to the fact that adipocytes are more sensitive to cold than other histological structures such as the epidermis, dermis, blood vessels, sweat glands, muscles and nerves, their apoptosis occurs before that of the other cells. 2,[7][8][9][10] The adipose tissue is placed in contact with cold plaques using a pressure applicator that thermally "kills" the fat without damaging the skin. 11 The dead cells are then removed metabolically, as with the fat found in food. 1,9 The present study statistically describes the experience of a referral center for this procedure in the Brazilian Southeast city of São Paulo.

METHODOLOGY
A cross-sectional study was carried out with 251 patients who spontaneously and randomly sought a private dermatologic practice for the treatment of localized fat. All patients in this study underwent only the cryolipolysis procedure with the Coolsculpting ® device (Zeltic Aesthetics, Pleasanton (CA), USA). The exclusion criteria for not undergoing this therapy were: cryoglobulinemia, cryofibrinogemia, cold urticaria and obesity grade I, II and III according to the Abeso's (Brazilian Association for the Study of Obesity and Metabolic Syndrome) body mass index.
The present study described the epidemiological profile of patients who underwent this procedure with the percentage analysis of the following variables: gender, age, number of sessions per area, distribution of body sites treated with the procedure, patient's satisfaction, independent observer evaluation and description and management of adverse events.
The patient satisfaction rate was determined by the following scale: 0 = unsatisfied, 1 = somewhat satisfied, 2 = satisfied and 3 = very satisfied. The results were compared by an independent observer in the before the treatment and eight months after the treatment based on three dimensions digital photographs (Vectra M3 ® , Canfield), according to the following scale: 0 = absence of improvement, 1 = little evident improvement and 2 = evident improvement.

RESULTS
The authors treated 251 patients (38 men and 213 women) who had accumulation of localized fat, with a total of 740 areas treated. Ninety-six (96) patients underwent the procedure in more than one area, with 8 having undergone more than one session in the same area (the most common combination being  Table 1. It is worth to note that all areas required two sessions in order to acquire some satisfactory result, except for the anterior region of the abdomen, in which 21% of cases required only one session. Adverse events observed were: late pain of varying duration within two to three days after the procedure, appearance of hematomas and 5 cases of panniculitis. The events were managed with analgesia, using 30mg codeine associated with 500mg paracetamol, 50U sodium heparin with 2.067mg nicotinate benzyl, and ultrasound sessions (Accent Ultra ® , LBT Lasers, São Paulo, Brazil), respectively. Dermatol 2015;7(4):316-9.

DISCUSSION
Cryolipolysis targets only the fat cells in the selected region. The physician chooses the region to be treated and areas to place the application device. The device pulls and holds the fat between its two panels, automatically cooling it for one hour. The sensation is that of a firm pull, and the freezing action does not affect the skin or other organs and tissues. The epidermis and dermis are protected by a gel film during the session. For this reason, given that the contraindications for the procedure are observed, it can be performed in patients of any age, which is consistent with the present study, which included patients between 13 and 69 years of age. The average age of 40 years observed in the present study is consistent with the literature, coinciding with the age when the greatest level of concern with the body takes place. 11 The majority of the population in the present study lived in the Brazilian State of São Paulo, and in most of the cases had greater concern with the abdominal region (67.60%). This can be due to the trend to be overweight that is expected to occur in the population of more developed areas and the fact that the abdominal region is the primary body site that develops localized fat.
The rate of patient satisfaction and the independent observer evaluation carried out before treatment and eight months after the last session through 3D digital photographs presented high scores in the present study. The reduction of the treated fat, with some studies finding an average of 22.4% four months after the treatment, 2,4,9,12 can explain the high effectiveness of the method and the resulting high degree of satisfaction in patients with good indication.
Another point of agreement would be the histological evaluation carried out in some studies, which confirm the gradual selective reduction of adipose tissue in humans and animals after cryolipolysis sessions. 2,9,13,14 The exclusion of patients with obesities grades I, II and III according to the Abeso's body mass index contributed to the correct selection of the study patients, as well as to the high level of positive results.
All patients had late pain that lasted for two to three days after the procedure, nevertheless having been easily controlled by analgesia using 30mg codeine associated with 500mg paracetamol. The cases presenting hematomas were managed with 50U heparin sodium combined to 2.067mg nicotinate benzyl. The five cases of panniculitis were described as painful subcutaneous nodules, with absence of systemic signs or symptoms. The patients were followed up on weekly sessions with non-focused ultrasound (Accent Ultra ® , LBT Lasers, São Paulo, Brazil), with complete clinical improvement of the picture. The authors of the present study did not observe bacterial or mycobacterial infections, or temporary alterations in the peripheral sensory nerves' function.

CONCLUSIONS
Cryolipolysis is a non-invasive method for the selective reduction of fat that has shown efficacy in the reduction of subcutaneous tissue with minimal and reversible side effects in the present study. This technology should be used by dermatologists who have experience with it, always observing the contraindications, in order to achieve good results. l