The Safety and Efficacy of Cryolipolysis: A Systematic Review



In the past decade, the practice of body contouring using cryolipolysis has increased tremendously. While numerous anecdotal reports extol the efficacy of this product, the majority of these studies are small, retrospective case-series that lack control groups.


The authors aim to systematically review available literature to better illustrate the efficacy and safety of this new procedure.


A systematic literature review performed using MEDLINE, Embase, PubMed, and Cochrane databases identified all published studies evaluating cryolipolysis for body contouring.


A total of 34 articles up to February 2015 were identified. Nineteen articles matched the selection criteria and were included in the analysis. Sixteen were evaluated in the final analysis. A total of 1445 patients had reportable data for analysis of the safety profile. Twelve patients (0.82%) reported complications with the most common being diminished sensation lasting greater than 4 weeks. An aggregate total of 295 patients had objective data for evaluation of tissue reduction. The mean time from procedure to objective outcome evaluation was 3.83 months. The mean reduction of subcutaneous tissue was 19.55% with respect to a designated control site.


Selective cryolipolysis appears, at short-term follow-up, to reliably decrease subcutaneous tissue deposits. Reported complications are uncommon and appear to resolve without intervention. Future studies should aim to optimize patient selection and treatment characteristics while obtaining long-term follow-up data.

The desire to remove or reshape undesirable focal fat deposits has increased the popularity of body sculpting procedures. Liposuction is considered to be the most effective procedure to reduce such deposits. However, it is not without significant risks and necessary recovery time. Abnormal body contours, infection, nerve damage, seroma, hematoma, and risks associated with general anesthetic or intravenous sedation are all potential complications of liposuction. 1 Therefore, options that reduce invasiveness, risks, and recovery time while still being effective are an appealing alternative. One such procedure is cryolipolysis, which has received FDA clearance for treatment of the focal fat deposits in the flanks (2010, K080521), abdomen (2012, K120023), and thighs (2014, K133212). 2 The practice of body contouring using cryolipolysis (CoolSculpting, Zeltiq Aesthetics, Pleasanton, CA) has increased tremendously. 3

In cryolipolysis, fat cells are preferentially destroyed by a controlled thermal reduction. Exposure to below normal, but above freezing, temperatures induces apoptosis-mediated cell death. 4 The adipocytes are more sensitive to the cooling process than other cells, resulting in minimal collateral damage to surrounding tissues. 5 A subsequent inflammatory response beginning on day 3 and peaking around day 14 removes the damaged adipocytes. 1 The resolution of inflammation and lipid metabolism is thought to be completed by 3 months after treatment. 6Authors of previous studies in porcine models and in humans have demonstrated this process results in a reduction of the treated area's fat layer. 4

The procedure is easily performed in a clinical setting without anesthetics or analgesics. The tissue containing the focal fat deposit is drawn into an applicator with the assistance of a vacuum after coupling gel has been applied. Cooling panels on either side then begin a controlled thermal reduction that is maintained for a time period between 45 and 60 minutes. The cooling intensity factor (CIF) is a modifiable variable measured in mW/cm 2 that determines the rate of cooling. A larger CIF corresponds to an increased average energy extraction per cm 2 during treatment. 4The treatment lasts for a preset time, the device then shuts off and is removed. Sasaki et al inserted a temperature probe into the treated area and revealed that tissues reached as low as 9°C. The lowest temperatures were at the 60-minute mark, or completion of treatment, and temperatures returned to baseline within 60 minutes after device removal. 7 The patient is able to immediately return to regular daily activities with no restrictions and minimal discomfort. 

While numerous anecdotal reports extol the efficacy of this product, the majority of these studies are small, retrospective case series that lack control groups. The authors aim to systematically review available literature in an effort to fully understand the indications and efficacy of the procedure while focusing only on studies with objective evidence on safety and outcomes.


Search Strategy

A literature search was performed by the investigators in February 2015 using the following electronic databases: MEDLINE, Embase, PubMed, and Cochrane. The keywords used were “cryolipolysis” and “CoolSculpting.”

Article Eligibility

Inclusion criteria included studies containing objective data on safety or efficacy of cryolipolysis. Exclusion criteria were nonEnglish articles, case reports, and studies not involving humans. For safety profile analysis, only studies that specifically described complications and/or safety data were included for analysis. For efficacy analysis, only studies that specifically described objective measurements of tissue loss and compared this to a designated control site were included for analysis. Objective measurement analysis included tissue caliper measurements, ultrasound-assisted measurement of tissue thickness, and 3-dimensional (3D) volume analysis.

Data Extraction

The following data were extracted from each primary article and used for comparison: sample size, age, gender, body mass index (BMI), treatment variables, outcome measures, results, and complications.


Articles up to February 2015 were included. A diagram of the selection of articles is shown in Figure 1 . The initial search yielded 59 articles, 25 of which were duplicate manuscripts. Inclusion and exclusion criteria were then applied to a review of the abstracts of the remaining 34 articles; 15 were eliminated based on this review. The remaining 19 articles were fully examined. Sixteen articles matched the selection criteria and were included in the analysis. Characteristics of the included studies are presented in Table 1 .

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