Dynamic Cooling Protects Epidermis For Effective Laser Treatment

Stephen Eubanks, MD, Dermatology & Laser Center, Denver, Colorado

Laser treatments for vascular lesions and hair removal promise patients genuine relief, but often at a risk. Without an effective method for cooling the epidermis while maintaining the temperature of the dermis, laser treatments can result in pain, blistering, scarring and/or pigmentary disturbances.

Traditional modes – topical applications and contact cooling – chill imperfectly, too long and too generally. Such methods force laser energy to be diverted to reheat the dermis. Therefore, either treatment fluence needs to be raised or the therapeutic value is diminished.

ENDS PAIN REDUCTION/EFFICACY COMPROMISE

This trade-off between pain reduction and efficacy is mitigated with the Dynamic Cooling Device^TM (DCD^TM) available only with the GentleLASE® (long-pulse alexandrite laser for hair removal and large leg veins) and ScleroPLUS^TM (pulse dye, laser for the treatment of vascular lesions) laser systems, both from Candela Corporation.

The DCD sprays the skin with a brief, consistent spurt of GentleCOOL^TM liquid cryogen just prior to laser pulse. Skin surface temperatures are reduced to between 5 °C and –9 °C, up to twice as low as temperatures reached with contact cooling.¹ The DCD is proven to cool selectively, temperature reductions are localized to approximately 200 µm of superficial tissue.² As a result, DCD allows for use of fluences safely, giving excellent results with minimal thermal damage or patient discomfort. Further, it permits the high treatment fluences shown to be required for long-term hair reduction.³

OFFERS TREATMENT FOR DARKER SKIN TYPES

Patients with darker skin types are more prone to side effects as additional melanin absorbs a greater amount of laser energy. Because achieving clearances has required intolerable and potentially damaging fluences, these patients are often regarded as poor candidates for treatment. Yet studies have demonstrated that reduction of pain with DCD is most pronounced in patients with dark skin types.⁴ Therefore, high fluence levels may be employed, which may increase success rates with these patients.

"I'm able to provide faster treatment, even at the highest fluences, while minimizing thermal injury. Patients experience excellent clearance."

Stephen Eubanks, MD Denver, Colorado

DCD also obviates the need to use long laser pulses, tens of milliseconds for hair removal, in order to minimize skin injury. Long laser pulses are less effective in the removal of fine hair.⁵

DELIVERS CONVENIENCE AND CONTROL

With DCD, cooling is consistent, precise and virtually undetectable to the user. The device coordinates cryogen spray and laser pulse in accordance with operator specifications. Unlike contact cooling where temperature reduction varies according to operator-applied pressure and individual skin-surface thermal contact, DCD delivers uniform cooling with each pulse and every treatment.

It allows for a larger spot size, which speeds treatment sessions. Finally, DCD is completely integrated within Candela laser systems. There is no additional apparatus, the operator's view of treatment area remains unobstructed, and there is none of the operator fatigue associated with some contact cooling methods.

DCD represents a significant advance, offering optimal cooling for both patient comfort and excellent treatment efficacy. For more information about DCD, contact Candela Corporation, 530 Boston Post Road, Wayland, MA 01778, 800-654-6027, www.cizr.com.

REFERENCES

¹ Anvari B, Milner TE, Tanenbaum BS, Nelson JS. A comparative study of human skin thermal response to sapphire contact and cryogen spray cooling. IEEE Trans Biomed Eng. July 1998;45(7):934-94l.

² ibid.

³ Anderson RR. Harvard University.

⁴ Waldorf HA, Alster TS, McMillan K, Kauvar ANB, Geronemus RG, Nelson JS. Effect of dynamic cooling on 585-nm pulsed dye laser treatment of port-wine stain birthmarks. Dermatol Surg. 1997;23:657-662.

⁵ Anderson RR. Harvard University. Hair Removal Panel at ASLMS Annual Meeting, April 1999, Orlando, Fla.

⁶ Pope, K. Senior Scientist, Candela Corporation. Epidermal Protection Factor: Candela’s Dynamic Cooling Device^TM. Candela Corporation. Technical Update, vol. 2, March 1999.