Energy-based therapy use in gynecology dates back to the early 1970s, when ablative carbon dioxide (C02) lasers were employed to treat cervical erosions.1 Soon after, reports were published on laser treatment for diethylstilbestrol-associated vaginal adenosis, laser laparoscopy for adhesiolysis, laser hysteroscopy, and laser genital wart ablation.2 Starting around 2011, the first articles were published on the use of fractional C02 laser treatment for vulvovaginal atrophy.3,4 Use of laser and light-based therapies to treat “vaginal rejuvenation” is now increasing at an annual rate of 26%. In a few years, North America is expected to be the largest market for vaginal laser rejuvenation. In 2016, more than 500,000 feminine rejuvenation procedures were performed in the United States, and it is estimated that more than 27,000 energy-based devices will be in operation by 2021.5
Clearly, there is considerable public interest and intrigue in office-based female genital cosmetic procedures. In 2018, the US Food and Drug Administration contacted 7 manufacturers of energy-based devices to request revision and clarification for marketing of these devices, since these technologies are neither cleared nor approved for cosmetic vulvovaginal conditions.6 The companies responded within 30 days.
In this article, we appraise the existing literature regarding the mechanism of action of energy-based therapies used in gynecology and review outcomes of their use in female genital cosmetic surgery.
Laser technology devices and how they work
LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser devices are composed of 1) an excitable medium (gas, liquid, solid) needed to emit light, 2) an energy source to excite the medium, 3) mirrors to bounce the light back and forth, and 4) a delivery and cooling system (FIGURE 1).
The electromagnetic spectrum is the range of all the wavelengths of light, including visible light, radio waves, infrared light, ultraviolet light, x-rays, and gamma rays (FIGURE 2). Most lasers used for the treatment of vulvovaginal disorders, typically C02 and erbium:yttrium aluminum garnet (Er:YAG) lasers, involve the infrared wavelengths.
The basic principle of laser treatment is to match the wavelength of the laser with the absorption spectrum of the desired target—a chromophore such as hemoglobin, melanin, or water (FIGURE 3). In essence, light is absorbed by the chromophore (which in vulvar and vaginal tissues is mostly water) and transformed into heat, leading to target destruction. In a fractionated (or fractional) laser beam, the laser is broken up into many smaller beams that treat only portions of the treatment area, with areas of intact epithelium in between the treated areas. At appropriately low thermal denaturation temperatures (45° to 50°C), tissue regeneration can occur through activation of heat shock proteins and tissue growth factors, creating neocollagenesis and neovascularization.
The concept of ablative resurfacing versus fractional resurfacing is borrowed from dermatology (FIGURE 4), understanding that tissue ablation and thermal denaturation occur at temperatures greater than 100°C, as occurs with carbonization of vulvar condylomata.
Continue to: In dermatology, fractionated lasers...