Skin in the spotlight: Cosmetic treatments

New solutions for spider veins 

It is estimated that almost three-quarters of all adult women suffer from spider veins, known as telangiectasias or sunburst varicosities, on their thighs, calves, and ankles. Since the most common causes are regular hormonal fluctuations and pregnancy, spider veins occur most often in women. Other factors that contribute to the development of spider veins include injury, hormone replacement or birth control pills, and family history. Conditions that put pressure on the veins, such as weight gain and sitting or standing for long periods of time, can also contribute to their development.

Sclerotherapy 

Spider veins are most often treated with sclerotherapy. The goal of sclerotherapy is to introduce a chemical intravascularly to cause irreversible endothelial cellular destruction, which leads to vascular fibrosis and obliteration. Several sclerosing solutions are commercially available for treatment of varicosities. They differ in their efficacies and safety profiles (see Table 1). The selection of solution and, equally important, its concentration and quantity depend on the type and site of the varicosity.

TABLE 1. Common sclerosing agents

	Solution	Category	Advantages	Disadvantages
	Sodium tetradecyl sulfate	Detergent	Painful only with extravasation, capable of sclerosing larger veins, FDA-approved	Necrosis with extravasation pigmentation, matting
	Polidocanol	Detergent	Always painless, rare necrosis	Urticaria at injection site, no pain to warn of arteriorlar injection, not FDA-approved
	Hypertonic saline	Hyperosmolar solution	Nonallergenic	Painful injections, necrosis, pigmentation, matting, FDA: off-label
	Chromated glycerin	Toxin	Rare matting, pigmentation, necrosis	Too weak for large veins, more viscous, possibly allergenic, not FDA-approved

Chromated glycerin 

Whereas the other sclerosants are already well-known agents in the US, chromated glycerin is a relative newcomer. First popularized in Europe, its use in sclerotherapy of leg veins is off-label in the US. It is weak, relative to other sclerosants, and is primarily useful in the sclerosis of small vessels. Its principal advantages are: it rarely causes hyperpigmentation, telangiectatic matting, or extravasation necrosis.

In a study comparing glycerin to another common sclerosant, sodium tetradecyl sulfate (STS), glycerin effectively cleared the spider veins more quickly, with less pain, and with fewer resulting side effects. A six-month follow up showed that legs treated with the glycerin had far greater clearance of spider veins by a margin of seven to one than the legs treated with STS.1

Foam sclerotherapy 

Foam sclerotherapy is yet another European import that is quickly gaining prominence in US dermatology. Foam sclerotherapy dates back to Orbach, who first proposed the use of foam in 1944.2 He found that shaking a sclerosant solution in a syringe with air produced large bubbles with a high air-to-liquid ratio. This foam proved to be effective in treating smaller veins, but not larger ones. Interest in the foam treatment faded for several decades, until Dr. Juan Cabrera introduced a new foam technique in 1993.3

Most recently, Frullini and Tessari have described other variations in the production of foam.4 The Tessari Method is now one of the most widely used techniques. It involves filling one syringe with a sclerosant and another syringe with air, then passing the material back and forth through the stopcock. The popularity of the Tessari Method can be attributed to its simplicity and low cost, as well as its efficacy in producing high quality foam.

Much has been published on the efficacy and safety of foam sclerotherapy, and it has been recognized to hold several advantages over traditional liquid sclerotherapy. In the latter technique, a liquid is injected and mixes with the blood in the vein, thereby diluting the concentration of the sclerosant. Foam, on the other hand, will displace the blood, allowing direct contact of the sclerosant with the endothelium. The efficacy of a given concentration of sclerosant is effectively increased when used as foam instead of liquid form. Accordingly, we can use a lower concentration of a given sclerosant to treat veins, which increases the safety of sclerotherapy. A given volume of liquid can produce up to four or five times its volume in foam, depending on the method used to generate the foam. Moreover, extravasated foam is much better tolerated by patients than extravasated liquid. Further, many phlebologists consider yet another advantage of foam to be the most significant: The air contained in the foam is echogenic, which dramatically increases visibility and accuracy when performing duplex-guided sclerotherapy.

Figure 1, Figure 2, Figure 3 illustrate sequential lateral views of a patient's thigh before, during, and after foam sclerotherapy.

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Figure 1. Spider veins on lateral thigh before sclerotherapy.

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Figure 2. During sclerotherapy—notice the immediate blanching of the vessels with foam injection.

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Figure 3. Clearance of spider veins after two sclerotherapy sessions.

A ten-year, prospective, controlled, randomized trial involving over eight hundred patients conducted by vascular surgeons in Europe compared six treatment options for varicose veins: liquid sclerotherapy, high-dose liquid sclerotherapy, multiple ligations, stab avulsion, foam sclerotherapy, and ligation followed by sclerotherapy.5 The report concluded that foam sclerotherapy appears to be more effective than standard-dose liquid sclerotherapy, and results can be comparable to surgery. Although effective for veins of all sizes, some have noted slightly higher rate of minor side effects, such as pigmentation, inflammation, and minimal necrosis when foam is used for small reticular veins and telangiectasias. Interestingly, this study also looked at lung scintigraphy in select patients who received foam. The investigators found no perfusion defect even after injections of up to 10cc of foam.

New light source applications 

Heat can have specific effects on collagen, the most abundant protein in the dermis. Studies indicate that collagen fibrils will contract when heated to the correct temperature over a period of time. This process may lead to the rise in tissue tightening due to the breakage of the intramolecular hydrogen bonds. However, exceeding the critical threshold causes the collagen fibrils to denature completely. The appropriate use of lasers and other light sources depends upon the user's skills in selecting the appropriate device of the necessary wavelength, in order to produce the desired clinical effect through its interaction with the target tissues.

The Holy Grail of laser technology remains the discovery of a laser or light source modality that can reduce wrinkles and other the signs of cutaneous photo-damage, while at the same time protecting the overlying epidermis from thermal injury. Excitingly, a number of these so-called nonablative laser treatments have been introduced in the past several years.

New methods in laser treatments smooth the skin by reorganizing dermal structural elements and increasing dermal volume, presumably through induction of collagen regrowth and remodeling as well as synthesis of new extracellular matrix material. None of these nonablative resurfacing techniques offer the efficacy of ablative laser skin resurfacing procedures using the carbon dioxide (CO2) or erbium:yttrium-aluminum-garnet (Er:YAG) lasers, but many patients find the low risk profile, minimal morbidity, affordability, and minimal healing time associated with these nonablative modalities to be attractive, despite the more modest, incremental benefits.6

Laser sources of visible light, infrared light, and near infrared light have all been used for non-ablative skin rejuvenation. Laser devices which have demonstrated usefulness include the N-Lite (585-nm, pulsed dye laser), Vbeam™ (595-nm, pulsed dye laser), Medlite (1046-nm, Nd:YAG laser), CoolTouch™ (1320 nm, Nd:YAG laser), and the SmoothBeam™ (1450-nm, diode laser).7, 8 Several broader spectrum pulsed light sources have been found similarly useful, including the Vasculite™ (515–1200 nm) and IPL Quantum™ (560–1200 nm) devices.

The mechanism of action of nonablative skin rejuvenation lasers remains uncertain. Two major hypotheses exist to explain their efficacy. The first suggests that the light energy (photon energy) is absorbed by water—and perhaps by collagen—causing a direct thermal effect on the collagen, as well as the extracellular matrix proteins or the dermal ground substance.

The second hypothesis suggests that light energy in the form of photons is absorbed by hemoglobin and melanin pigments. This, in turn, triggers the cutaneous vessels and adnexal structures to produce cellular mediators and growth factors that may stimulate a wound-healing type of response. The second mechanism would also give rise to indirect heating of the dermis and elicit a response similar to the first proposed mechanism. Other mechanisms at play in reducing cutaneous photodamage include reduction of superficial dyspigmentation (brown spots) and telangiectasia (red spots).

The Fraxel® fix 

Ablative lasers (CO2 and Er:YAG) provide the greatest improvement in photoaging, but lead to significant downtime. Nonablative lasers have very few adverse effects, but limited efficacy. Fractional photothermolysis (more commonly known as Fraxel) represents a compromise between the traditional ablative resurfacing with CO2/Er:YAG lasers and the nonablative lasers to improve skin texture and pigmentation.

Fraxel is a 1550-nm laser that produces thousands of microscopic thermal wounds called microscopic treatment zones (MTZs) at specific depths in the skin without injuring surrounding tissue.9 Unlike with CO2 resurfacing, wounding is not apparent because the stratum corneum remains intact during treatment, and the surrounding tissue also remains unaffected. While superficial epidermal damage leads to improvement of lentigines, controlled deep dermal injury also lead to neocollagenesis and subsequent long-term textural improvement.

With the application of topical lidocaine 30–60 minutes prior to treatment, and the use of cold air anesthesia during treatment, most patients tolerate Fraxel without the need for sedation. A full-face treatment typically requires approximately 30 minutes.

Fraxel has shown effectiveness in the treatment of facial rhytides, acne scars, surgical scars, melasma, and photodamaged skin. Side effects are transient and generally limited to erythema, edema, and flaking skin. Post-inflammatory hyperpigmentation is still possible especially in darker skin types, but is also transient. Patients in general report limited social activity for 2–3 days during recovery. As with nonablative laser modalities, multiple treatments are required.

Light source therapies for acne 

Medical therapies for acne have improved dramatically in recent years, yet important and frustrating limitations remain. Topical therapies have only partial efficacy as well as the potential for irritancy, particularly when used on adult skin in cold, dry climates. Compliance issues, public health risks of long-term antibiotic use, and the potential for adverse effects—particularly among women of childbearing age—remain concerns for some of the more potent systemic agents available for acne therapy. Laser and light-based treatments offer new therapeutic options for all patients suffering with acne, but these may be of particular interest for women of child-bearing potential, for whom systemic retinoid therapy may be problematic.

The pathophysiology of acne encompasses a multitude of factors, involving occlusion of the follicular orifice, comedone formation, bacterial overgrowth, and subsequent inflammation and rupture of the sebaceous follicle. Proprionobacterium acnes is the most common bacteria implicated in this process. One unusual feature of P. acnes is the ability of this bacterium to produce porphyrins as a byproduct of metabolism. This porphyrin production has been targeted by the first series of light technologies used to treat acne.

Among new technologies is the ClearLight System™, a high-intensity, narrow-band, blue light source that has demonstrated efficacy in the treatment of mild to moderate acne. The therapeutic benefit of this light source therapy relies on the absorption of specific wavelengths of visible light by the endogenous porphyrins produced by the cutaneous P. acnes.10 A different portion of the pathophysiologic mechanism of acne is addressed with laser systems, such as the SmoothBeam system. This laser treatment strategy targets the dermal sebaceous glands for thermal destruction.

Both the SmoothBeam and ClearLight System lasers offer the possibility of safe, effective acne therapy. In addition to treating the active, ongoing, inflammatory component of the acne itself, remodeling of acne scars may be approached through new collagen and extracellular matrix synthesis, induced by the non-ablative resurfacing techniques discussed previously.

Wrinkles and radiofrequency waves 

Recent advances in cosmetic skin procedures stress techniques that are noninvasive or nonablative, thus minimizing risk, discomfort, and healing time for the patient.11 In addition to laser technologies, radiofrequency devices have been recently introduced to accomplish these ends.

Radiofrequency wave treatment tightens deep tissue while sparing the epidermis from injury. The precise mechanism of action by which the delivery of radiofrequency energy and deep dermal heating induces tissue tightening remains unclear, as it does for other nonablative therapies.

The dermis is made up predominantly of type I collagen. Type I collagen itself is composed of three polypeptide chains which are stabilized in a triple helix arrangement by numerous intramolecular cross-links. These triple helices are then further aggregated in a parallel pattern to form collagen fibrils, which are stabilized by intermolecular hydrogen cross-links. It is these intermolecular cross-links that provide the dermis with its tensile properties, and it is these cross-links that are broken when the collagen is gently heated.

ThermaCool 

One new advance in skin treatment is the the ThermaCool TC™. This device has been hypothesized to deliver enough heat into a sufficiently large volume of tissue to cause immediate collagen contraction, followed by a significant wound healing response, resulting in gradual tissue tightening over time. It is thought that the the radiofrequency energy alters the triple helix molecular structure of the collagen molecule by heating it to a point where the intermolecular hydrogen bonds are broken, but not to an extent great enough that the intramolecular cross-links are broken.

Primary collagen fibril contraction occurs immediately, just as may be seen with ablative resurfacing technologies, such as the carbon dioxide laser. However, secondary phenomena, such as secondary collagen synthesis, are postulated to contribute to the apparent longer-term, incremental responses.3

The ThermaCool TC device causes thermal injury in the dermis, which stimulates a wound-healing response. It is believed that this may, in turn, lead to an increase in new skin formation and collagen production. This hypothesis is bolstered by a recent pilot study, which was able to demonstrate increased collagen gene expression in treated skin in response to radiofrequency wave treatment.11 The device has been granted clearance by the US Food and Drug Administration for the noninvasive treatment of periorbital wrinkles, accomplished by delivering radiofrequency energy to the skin with contact cooling to protect the epidermis.7 It has also been used successfully at sites other than the periorbital region: the brow, lower face and neck appear to respond equally well.12

A cryogen spray is used inside the treatment tip in order to create a cooling device that protects the epidermis from thermal injury. By employing this unique method of contact cooling prior to, during, and following application of the radiofrequency energy, a reverse thermal gradient is produced. The most profound heating occurs in the deep dermis while the epidermal surface is relatively protected from thermal injury.

Radiofrequency wave treatment using the ThermaCool TC device is typically performed in an outpatient setting with a topical anesthetic and nerve blocks. The procedure typically takes 30 to 60 minutes, and patients are able to resume routine activities immediately after treatment.12

The cosmetic improvement following this treatment is gradual, occurring in many cases over a period of 4–6 months. In trials, about 80% of patients showed a significant improvement, according to an objective assessment of their wrinkle severity, after a single treatment.13 Generally, the cosmetic changes are subtle, and are often most apparent to patients upon being shown pre- and post-treatment photographs. Younger patients and those treated with multiple passes tend to respond better to ThermaCool TC therapy.

Conclusion 

Given the improved safety, efficacy, availability, and affordability of new cosmetic dermatologic procedures, as well as the enormous attention that these procedures have garnered from the media, it is understandable why a growing number of men and women have questions about available treatments and the suitability of those treatments for themselves. When bombarded with an overload of information from the media about skincare science and high-tech “fixes”, these patients, who are primarily female, often turn to trusted care providers with whom they have already forged a strong relationship to help guide their decisions, even if these care providers are not dermatologic experts themselves.

Being aware of the mechanisms of action as well as the risks and benefits of new cosmetic procedures empowers care providers to, in turn, empower their patients with information. Accurate information, when relayed by a trusted medical professional, can help guide women towards making appropriate and safe decisions when seeking dermatological treatment.