Paradoxical Adipose Hyperplasia: A Rare but Treatable Complication of Coolsculpting

I very recently learned about a challenging complication of Coolsculpting. I have seen 2 to 3 patients in the past six months who sought surgical intervention for bulging fat in areas that were previously treated with Coolsculpting.

Left: before paradoxical adipose hyperplasia, Middle: paradoxical adipose hyperplasia after Coolsculpting, Right: after treatment with liposuction. From: Treatment of Paradoxical Adipose Hyperplasia following Cryolipolysis: A Single-Center Experience. Kelly, Michael E.; Rodríguez-Feliz, Jose; Torres, Carolina; Kelly, Emma. Plastic and Reconstructive Surgery142(1):17e-22e, July 2018.

The history tends to be the same in most cases: patients had mild to moderate fat excess and visited a medspa to undergo Coolsculpting. The patients were generally pleased after one or two treatments. After about three treatments, they noticed that the fat loss was plateauing and did not return for additional treatment. Months to years later, they developed- much to their surprise, excess fat recurrence in the areas that were treated. They came to me for evaluation for either radiofrequency skin tightening, liposuction, or abdominoplasty. In these three patients that I can directly recall, two were women and one was a man. The patients were all of Latin extraction, but this may just be a coincidence. Paradoxical adipose hyperplasia is a very challenging problem that can affect men and women who have been treated with Cryolipolysis. Cryolipolysis, better known as Coolsculpting, is a time-proven and effective way of reducing subcutaneous fat in the superficial layer without surgery and significant downtime. This procedure is widely available and does not require a plastic surgeon or MD to perform it. Multiple treatments are often necessary, but a modest improvement can be seen in many patients. According to online reviews the technology is generally satisfactory to patients who are not interested in having surgery, or who have mild to moderate fat excess.

I imagine that the incidence of this complication, paradoxical adipose hyperplasia, is exceedingly rare. When I asked one of the representatives from the company about its incidence, he reassured me that this condition occurs in one out of 70,000 cycles. As I have seen three patients in the past six months with this condition, I wonder if this is underreported or if the technology is that exceedingly popular. In any case, I believe it is in the best interest of my patients to understand what paradoxical adipose hyperplasia (PAH) is, what it means, and how it can be treated.

The cross-sectional anatomy of the soft tissue layer include skin, a superficial fat layer, a layer called “fascia” with fibrous fingerlike extensions, and a deep fat layer. Underneath the fat is muscle. While traditional liposuction targets the deep fat layer, and to a lesser extent the superficial fat, nonsurgical interventions like Coolsculpting target the superficial fat layer. By carefully freezing these fat cells, cell death occurs, and the byproducts are excreted through the liver in a way that does not adversely affect the overlying skin. The concept is brilliant! Although the improvements seen are modest, carefully selected patients are generally satisfied. On Realself, 76% of patients say Coolsculpting is “worth” the average treatment cost of $2425. To my understanding, this is an FDA-cleared technology that has been in existence for some time. The intent of this article is not to disparage Coolsculpting technology, but to educate patients on a potential complication.

So- what exactly is paradoxical adipose hyperplasia? It is just that. Paradoxical means surprising, unexpected, or the opposite of what you would expect. Adipose is a medical term for fat. Hyperplasia means overgrowth. In other words, when we get fatter, we do not get more fat cells. However, the fat cells that we have become larger, or hyperplastic. Patients who have high volume liposuction, for example, for a Brazilian butt lift, may never regain the fat where the fat has been harvested. People often ask me what happens when they gain weight. Fat doesn’t “regrow” in other body parts, but when fat accumulates, it does reaccumulate in fat cells that were not harvested in the first place. I have seen fat reaccumulate disproportionately in the back of the neck, thighs, knees, and lower legs in some patients. Therefore, areas like the abdomen and flank will not necessarily grow or expand the rate that the buttocks do in a Brazilian butt lift, after the fat has been harvested and successfully transferred. This same phenomenon can exist with paradoxical adipose hyperplasia. There are many thought as to why this occurs. Ultimately, my leading hypothesis is that the superficial that reservoir has been diminished after successful treatment with the Coolsculpting. This superficial fat originally acted as a retainer or an apron for the deep fat pad. I wonder whether loss of the superficial fat pad specifically in a certain area causes a knee-jerk, reflex-like overgrowth of the deep fat pad. The deep fat pad in these patients is no longer retained or confined by the superficial fat. Therefore, when the patient does gain a modest amount of weight, it is targeting the deep fat in areas where the superficial fact is now gone, and it becomes much firmer much more of a bulge and may even assume the shape of the applicator from which it arose.

Top: how Coolsculpting Cryolipolysis works. The blue is the treated area, the light yellow is the superficial fat reservoir, and the orange is the deep fat reservoir. Middle: Ideally, attenuation of superficial fat without skin injury will lead to a gentle depression in the region that was treated. The skin, fascial plane, and deep fat should not be interrupted. Lower: in paradoxical adipose hyperplasia, the deep fat is no longer “contained” by the superficial fat and cells therein grow disproportionately. The resulting bulge may take the form of the overlying applicator and is firm.

How do we treat paradoxical adipose hyperplasia? This is a great question. Unfortunately, there is very little in the literature about this rare but problematic complication of Coolsculpting. As a plastic surgeon, it seems intuitive to me to perform liposuction or direct removal of the deep fat compartment that is hyperplastic. This is how I have typically treated my patients with this condition. I have noticed in these patients that the fat that is harvested tends to be harder to resect than in patients who do not have this condition. The fat is much firmer, does not respond as well to liposuction, and even appears different than “normal” fat. The fat that is harvested is rigid, it tends to be grayer in appearance, and the overlying skin in these patients is more prone to requiring revisionary or secondary procedures. To date, I have not personally performed revisions on PAH cases that I’ve treated. However, in the literature it appears that approximately 50% of patients who require surgery for paradoxical adipose hyperplasia will require a secondary procedure for recurrence or persistent contour irregularity. Secondary procedures may include additional targeted liposuction revision, radiofrequency tightening of the overlying skin (i.e., BodyTite), or abdominoplasty. It is difficult to convey this to patients who were originally seeking a nonsurgical option. In addition, many of these patients, especially those were appropriately selected, do not necessarily have redundant skin. Rather, they have a bulge.

While I have found liposuction of these areas particularly challenging due to the firm and stubborn nature of the fat that is suctioned, this can be performed safely on an outpatient basis, and in many cases can be performed awake in the comfort of our office. Please do not hesitate to call 949-432-4730 if you or someone you know may have paradoxical adipose hyperplasia resulting from cryolipolysis, better known as Coolsculpting.