A humorous romp through a promising new technique in aesthetic medicine from one cryonicist’s (warped) point of view.

Figure 1: Before cryopreservation (L) and after cryopreservation (R).

As everyone involved in cryonics for more than a fortnight is sadly aware, cryonics doesn’t sell. Indeed, if we were pitching a poke in the eye with a sharp stick, we’d more than likely have more takers than we’ve had trying to ‘market’ cryonics to the public. To see evidence that this is so, you need only wander around a shopping mall on a weekend and observe all the (painfully) stainless steel lacerated and brightly colored needle-pierced flesh sported by the young and trendy and increasing by the old and worn, as well.

Yes, it’s clear; we misread the market, to our lasting detriment.

It’s true that we’ve tried the ‘you’ll be rich when you wake you up line,’ and heaven knows we’ve beaten the ‘you’ll be young and beautiful forever’ line, well, virtually beaten it to death. And while people are certainly interested in great fortune and youth, both of these things share the same unfortunate shortcoming, namely that they are things that people either don’t have but want, or do have and don’t want to lose. As anyone who is really savvy at marketing will tell you, the best way to sell something is to promise (and preferably be able to deliver) that you can get rid of something that people have and really don’t want – something that is ruining the quality of their life, destroying their health, draining their pocketbook and, worst of all, making them really, really ugly.

So, it turns out that for onto 50 years now, we’ve missed the real selling point of cryonics that’s been there all along: IT WILL MAKE YOU THIN! Guaranteed!

Can such a claim be true? Well, surprisingly, the answer would seem to be an almost unqualified, “Yes!”

Recently it’s been discovered that adipocytes, the cells responsible not only for making you fat, but for making you hungry, as well, are particularly susceptible to a phenomenon in cryobiology that has proved a nettlesome (and only recently (partially) overcome) barrier to solid organ cryopreservation: chilling injury. Quite apart from freezing damage due to ice crystals forming, adipocytes are selectively vulnerable to something called ‘chilling injury.’ ^1-5 Chilling injury occurs when tissues are cooled to a temperature where the saturated fats that comprise their cell membranes (external and internal) freeze. You see, saturated fat, which is the predominant type of fat in us humans, freezes well above the temperature of water – in fact, it freezes at just below room temperature. That’s why that big gash of fat on the edge of your T-bone steak is stiff and waxy when it is simply refrigerated, and not frozen.

Figure 2: Chilling injury is thought to result from crystallization of cell membrane lipids.

Chilling injury isn’t really well understood. In the days before both cryobiology and indoor heating, humans used to experience a very painful manifestation of it in the form of chilblains – tender swelling and inflammation of the skin due to prolonged cold exposure (without freezing haven taken place). In the realm of organ preservation it is currently thought that chilling injury occurs when cell membranes are exposed to high subzero temperatures (-5^oC to -20^oC), again, in the absence of freezing.

There is evidence that the lipids (fats) that make up the smooth, lamellar cell membranes undergo crystallization when cells are cooled much below 0 deg C. Since the crystals are hexagonal in shape and have a hole in the middle, this has the effect of creating a pore or hole in the membrane. Cells don’t like that – those holes let all kinds of ions important to cells keeping their proper volume and carrying on their proper metabolic functions leak in and out, as the case may be. This isn’t merely an inconvenience for cells, it’s downright lethal. Without boring you with technical details, it is possible to partially address this state of affairs in organ preservation by adjusting the ‘tonicity’ of the solution bathing the cells: oversimplifying even more, this means by increasing  the concentration of salts to a concentration higher than would normally be present

Figure 3: Contouring of the skin in a pig subjected to brief, subzero cooling of subcutaneous fat.

But, to return to our chilled adipocytes and the promise not only of weight loss, but of a fat-free future; adipocytes are killed, en masse, when their temperature is dropped to between 0 and -7^oC. Within a few days of exposure to such temperatures they undergo programmed cell death (apoptosis) and within a couple of months they are phagocytized by the body; and all that ugly and unwanted fat is carted off to be used as fuel by the liver. Now the rub would seem to be that this effect is most pronounced when the temperature of the tissue is cooled to below the freezing point of water and held there – preferably for a period of 10 minutes or longer.

That sounds dire, doesn’t it? What about the skin, the fascia, blood vessels, and the other subcutaneous tissues that will FREEZE (in the very conventional sense of having lots and lots of ice form in them)? Well, the answer, as any long-time experimental cryobiologist will know (even if he won’t tell you) is: pretty much nothing. Way back in the middle of the previous century, a scientist named Audrey Smith and her colleagues at Mill Hill, England found that you could freeze hamsters ‘solid’ – freeze 70+% of the water in their skin and 50% of the water in their bodies – and they would recover from this procedure none the worse for wear. Similarly, those of us who have carelessly handled dry ice for a good part of our lives will tell you that we see parts of our fingertips turn into stiff chalky islands of ice all the time, with the only side effect being a bit of temporary numbness that resolves in a few days to a week – certainly a side effect well worth it to avoid the considerable inconvenience of rummaging around to find a pair of protective gloves.

Figure 4: The Zeltiq Cool Sculpting Cryolipolysis device.

But alas, we scientists (most of us, anyway) are not a very entrepreneurial lot, and so we never thought either of inventing the Zeltiq^TM cryolipolysis system, or using ‘the thin-new-you’ as a marketing tool for cryonics.

Yes, that’s right; some very clever folks have found a way to make a huge asset out of a colossal liability – to organ preservationists, anyway. Around 2004 a Minneapolis dermatologist named Brian Zellickson, MD, who specialized in laser and ultrasonic skin rejuvenating procedures, made a not so obvious connection. Both laser and skin ‘face-lifting’ and skin ‘rejuvenation’ procedures rely on the subcutaneous delivery of injuring thermal energy to the tissues of the face, or other treated parts of the body (cellulite of the buttocks and thighs are two other common areas for treatment). These energy sources actually inflict a second degree burn in a patchy and well defined way to the subdermal tissues.

Now this may seem a very counterintuitive thing to do if you are trying to induce ‘rejuvenation’ or ‘lift’ a sagging face. But if you think about it, it makes a great deal of sense. As any burn victim will tell you, one of the most difficult (and painful) parts of recovery is stretching the highly contracted scar tissue that has formed as a result of the burn injury. Indeed, for many patients with serious burns over much of their body, the waxy, rubbery and very constricting scar tissue prevents the return of normal movement, and can lock fingers and even limbs into a very limited range of motion. Many burn victims must do painful stretching exercises on a daily basis to avoid the return of this paralyzing skin (scar) contracture.

And it must be remembered that aged skin – even the skin of the very old – can still do one thing, despite the many abilities it has lost with age, and that thing is to form scar tissue in response to injury. Thus, laser and ultrasonic heating of normal (but aged) skin induces collagen proliferation and large-scale remodeling of the skin. For all the bad things said about scar tissue it is still a remarkable achievement in that it does constitute regenerated tissue. Regenerated tissue which does the minimum that normal skin must do to keep us alive: provide a durable covering that excludes microbial invasion, and prevents loss of body fluids. By injuring the tissue just below the complexly differentiated layer of the dermis (with its hair follicles, sweat glands and highly ordered pigmentation cells) much of the benefit of ‘scarring’ is obtained without the usual downsides.

The injured tissues respond by releasing collagen building cytokines as well as cytokines that result in angiogenesis (new blood vessel formation) and widespread tissue remodeling. And all that newly laid down collagen contracts over time, tightening and lifting the skin – and the face it is embedded in. These techniques may justly be considered much safer versions of the old fashioned chemical face peel, which could be quite effective at erasing wrinkles and achieving facial ‘rejuvenation,’ but was not titrateable and was occasionally highly unpredictable: every once in awhile the result was disastrous burning and accompanying long term scarring and disfiguration of the patient’s face.

St some point Dr. Zellickson seems to have realized that the selective vulnerability of adipocytes to chilling offered the perfect opportunity for a truly non-invasive approach to ‘liposuctioning’ by using the body’s own internal suctioning apparatuses, the phagocytes, to do the job with vastly greater elegance and panache than any surgeon with a trocar and a suction machine could ever hope to do. Thus was invented the Zeltiq Cool Sculpt^TM cryolipolysis machine.⁶

Figure 5: The cooling head of the Zeltiq devive equipped with ultrasonic imaging equipment and a suction device to induce regional ischemia and hold the tissue against the cooling surface.

The beauty of cryolipolysis is that it is highly titrateable, seems never to result to in excessive injury to, or necrosis of the overlying skin, and yields a smooth and aesthetically pleasing result. Not unjustifiably for this reason it is marketed under the name Cool Sculpting^TM. The mechanics of the technique are the essence of simplicity. The desired area of superficial tissue to be remodeled is entrained by vacuum in a cooling head equipped with temperature sensors, an ultrasonic imaging device, and a mechanical vibrator. The tissue in the cooling head is sucked against a conductive surface (made evenly conductive by the application of a gel or gel-like dressing to the skin) where heat is extracted from it. The tissue is cooled to a temperature sufficient to induce apoptosis in the adipocytes, while at the same time leaving the overlying skin untouched. The depth of cooling/freezing is monitored by ultrasound imaging and controlled automatically by the Zeltiq device.  At the appropriate point in the cooling process the tissue is subjected to a 5 minute period of mechanical agitation (massage) which helps to exacerbate the chilling injury, perhaps by nucleating the unfrozen fat causing it to freeze.⁷ When the treatment is over, the device pages an attendant to return to the treatment room and remove it.

The tissue under vacuum is also made ischemic – blood ceases to flow, and this has the dual advantage of speeding the course of the treatment by preventing the blood borne delivery of unwanted heat – and more importantly, by making the cooling more uniform, predictable and reproducible. It also has the effect of superimposing ischemic injury on top of the chilling injury which is something that seems to enhance adipocyte apoptosis. The whole treatment, in terms of actual cooling time, takes about 60 minutes. In the pig work which served as the basis for the human clinical treatments, the duration of treatment was only 10 minutes: but the cooling temperature was also an ‘unnerving’ -7^oC. The degree of temporary and fully reversible peripheral nerve damage (that temporary numbness us ‘dry ice handlers’ know so well) was more severe at this temperature, although it resolved in days to a week or two, without exception.

As previously noted, cryolipolysis causes apoptosis of adipocytes and this results in their subsequently being targeted by macrophages that engulf and digest them. This takes time, and immediately after treatment there are no visible changes in the subcutaneous fat. However, three days after treatment, there is microscopic evidence that an inflammatory process initiated by the apoptosis of the adipocytes is underway, as evidenced by an influx of inflammatory cells into the fat of the treated tissues. This inflammatory process matures between seven and fourteen days after treatment; and between fourteen and thirty days post-treatment, phagocytosis of lipids is well underway. Thirty days after treatment the inflammatory process has begun to decline, and by 60 days, the thickness of interlobular septa in the fat tissue has increased. This last effect is very important because it is weakness, or failure of the interlobular fat septae that is responsible for the ugly ‘cottage cheese’ bulging that is cellulite. Three months after the treatment you get the effect you see below on the ‘love handles’ of this fit, and otherwise trim fellow. Thus, it is fair to say that Cool Sculpting^TM is in no way a misnomer.

Figure 6: Art left is a healthy, fit young male who has persistent accumulation of fat in the form of ‘love handles’ that are resistant to diet and exercise and the same man 3 months after cryolipolysis.

Does cryolipolysis really work? The answer is that it works extremely well for regional remodeling or sculpting of adipose tissue – those pesky love handles, that belly bulge around the navel, that too plump bum, or those cellulite marred thighs. So far it has not been used to try and ablate large masses of fat – although there seems no reason, in principal, why this could not be done using invasive techniques such as pincushioning the fat pannus with chilling probes, as is done with cryoablation in prostate surgery. However, this would be invasive, vastly more expensive, and likely to result in serious side effects.

And that was one of the really interesting things about the research leading up to FDA approval of cryolipolysis: it seems to cause no perturbation in blood lipids, no disturbance of liver function (the organ that has to process all that suddenly available fat) and no global alterations in immune function. It seems to be safe and largely adverse effect free. There is some localized numbness (as is the case in freezing of skin resulting from handling dry ice) but it resolves without incident with a few weeks of the procedure.⁸

So, all of this makes me wonder, since human tissues tolerate ice formation and respond to it in much the same way as they do to laser or ultrasound ‘rejuvenation’ (depending upon the degree of damage) a logical question is, “would it be possible to use partial freezing of the skin – just enough to provoke the remodeling response – as a method of facial rejuvenation?” It should be safer than a chemical people and it is, like laser and ultrasound therapy, titrateable.

Figure 7: “Gad darn it, this shiny gold stuff keeps getting into the silt I’m tryin to git out of this here river!”

Which returns me to the whole subject of cryonics: fat is very poorly perfused and it seems unlikely that things done to moderate or abolish chilling injury will be nearly so effective for the adipocytes in fat (if it they are effective at all). That means that we might well all come back from our cryogenic naps not only young, via the magic of nanotechnology and stem cell medicine, and rich via the miracle of compound interest (which none other than Albert Einstein once remarked was “the most powerful force in the universe”), but also THIN! For all these years organ cryopreservationists, like Fahy and Wowk, have been panning for the mundane silt of a way around a chilling injury⁹ all the while discarding the gleaming nuggets of gold that were persistently clogging up their pans.

We cryonicists should not repeat their error and should realize a good thing when we see it. Now, for the first time, we can credibly claim that if you get cryopreserved you’ll come back not only young and rich, but young and rich and beautiful and thin!

Methinks there must be very few in the Western World today, man woman or child, who can resist a product that has all that to offer – and which, by the way, bestows practical immortality in the bargain.

Ok, Ok, maybe we shouldn’t mention that last part about immortality; it might scare the children.

REFERENCES:

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2)     Diamantis S, Bastek T, Groben P, Morrell D. Subcutaneous fat necrosis in a newborn following icebag application for treatment of supraventricular tachycardia. J Perinatol 2006;26:518–

3)     Lidagoster MI, Cinelli PB, Levee´ EM, Sian CS. Comparison of autologous fat transfer in fresh, refrigerated, and frozen specimens: an animal model. Ann Plast Surg 2000;44:512–5.

4)      Wolter TP, von Heimburg D, Stoffels I, et al. Cryopreservation of mature human adipocytes: in vitro measurement of viability. Ann Plast Surg 2005;55:408–13.

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8)     Coleman SR, Sachdeva K, Egbert BM, Preciado J, Allison J. Clinical efficacy of noninvasive cryolipolysis and its effects on peripheral nerves. Aesthetic Plast Surg. 2009 ul;33(4):482-8. Epub 2009 Mar 19. PubMed PMID: 19296153.

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