Cryolipolysis to reduce cellulite through controlled cold exposure.

Cellulite is a skin alteration that affects women postpubertal with a prevalence of 70 to 80% and that can occur in the pelvis, lower limbs, and abdomen. It presents as an uneven, dimpled surface described as "orange peel" skin, with small indentations and lumps visible on the surface. Depending on its stage, it may be apparent when the skin is pinched or present at all times. There are different types: fatty, aqueous, and fibrous, each with a specific mechanism.

The adipose cellulite is linked to lipid overload and to an increase in adipocyte volume, the hypodermal cells that compress surrounding tissues and disrupt blood and lymph circulation. The aqueous cellulite, by contrast, is due to circulatory issues and water retention. It is associated with poor venous and lymphatic return, causing tissue swelling through water infiltration. The fibrous cellulite is an embedded, hard form with occasional pain that may take on a purple hue. It results from the hardening of collagen fibres surrounding adipocytes in the hypodermis. This hardening is linked to glycation, where sugars bind to the fibres, altering their structure and flexibility.

Cryolipolysis is a non-invasive technique that involves exposing fat cells to intense cold to destroy them. A device applies targeted cooling to the chosen areas during a session. Skin and fat cell temperatures drop to −5 to −10 °C. Fat cells are more sensitive to cold than other skin cells because they consist of lipids with a higher freezing point. At these temperatures the lipids crystallise, forming ice crystals. This crystallisation damages adipocyte cell membranes and disrupts their integrity. The process of apoptosis then begins, releasing the fats stored in the cells into the body. These fats are cleared by the lymphatic system over the following weeks. Changes appear over time. It takes one to three months for cells to break down and be naturally eliminated

Although used to reduce localised fat deposits, some studies suggest it could have a beneficial effect on the appearance of cellulite adipose. When these cells are destroyed by cold, the amount of fat in the treated area decreases, which may reduce the appearance of dimples.

A study published in Dermatologic Surgery aimed to assess the effect of cryolipolysis on fat deposits and its impact on skin texture, laxity and cellulite. After 16 weeks, 11 subjects who underwent cryolipolysis reported improved skin firmness and elasticity and reduced thigh dimpling. These outcomes were rated on a scale from 0 to 3, with 3 indicating a significant improvement. On average, cellulite improvement was rated at 1.5, indicating a moderate effect. However, some participants noted a more pronounced improvement, ranging from moderate to significant (score of 2 to 3).

These findings should be interpreted with caution, as the small number of subjects and limited studies available do not allow confirmation of a direct effect of cryolipolysis on cellulite reduction.

This procedure is suitable for treating body areas such as the abdomen, inner thighs, back, flanks and infragluteal folds. It is contraindicated for pregnant or breastfeeding individuals. It is unsuitable for those with cold-related conditions such as cold urticaria or hernia.

According to scientists, cells that die can no longer reproduce. However, if an individual regains weight, since the remaining cells can still expand, new unsightly areas may appear. Furthermore, cryolipolysis gives satisfactory results on fatty cellulite but is less effective on aqueous cellulite caused by poor blood circulation or water retention. It is ineffective on fibrous cellulite that is painful and persistent.

Side effects may occur after the session, such as redness or mild swelling of the treated area. Some individuals may feel discomfort. They may experience pain or tingling, even burns, peripheral sensory neuropathies, hyperpigmentation or inguinal hernias in the treated area. These symptoms resolve within 15 days. To prevent them, the dermatologist always examines the skin before performing cryolipolysis.

• VERGNANINI A. L. & al. Cellulite: a review. Journal of the European Academy of Dermatology and Venereology (2002).

• HUMPHREY S. & al. Cryolipolysis and Skin Tightening. Dermatologic Surgery (2014).

• NAOURI M. Efficacité de la cryolipolyse Cristal™. Étude rétrospective sur 1 an chez des patients ayant payé leur traitement. Annales de Dermatologie et de Vénéréologie (2015).

• MISHRA V. & al. Cellulite: a review with a focus on subcision. Clinical, Cosmetic and Investigational Dermatology (2017).

• KAMINER M. S. & al. Insights Into the Pathophysiology of Cellulite: A Review. Dermatologic Surgery (2020).