Carbon Dioxide Laser Treatment Using Methylene Blue–Assisted Sinus Tract Identification in Hidradenitis Suppurativa
For more than 20 years, the authors have treated HS lesions with the CO2 laser.5,6 Initially, the area for treatment is selected, cleaned, and delineated with ink. After local anesthesia, fistulas, scars, and other pathological tissues are removed using a Limmer (Berlin, Germany) UNILAS Touch Pro CO2 laser with wavelength 10,600 nm, at 30 to 60 W, slightly out of focus, with continuous 0.2-millisecond scanner-assisted pulses of diameter 3 to 5 mm. The diseased tissues, including fistulas, are vaporized repeatedly, layer by layer, under direct visual examination. The treatment is continued until healthy subcutaneous fatty tissue is reached. The resultant ulcers are left to heal by secondary intention.
As stated by Drs. Grimstad and Ingvarsson, it is accurate that the use of methylene blue allows for the potential minimization of the treatment area. However, it is the authors' experience that methylene blue is not reliable for delineating the entire extent of involved fistulas, and therefore, its use for this purpose increases the risk of retention of residual fistulas and other pathological tissues. The authors believe that by potentially leaving diseased tissue behind, CO2 laser treatment using methylene blue will often be incomplete and thereby increase recurrence risk for HS. By contrast, the authors' CO2 laser technique using layer-by-layer vaporization grants the dermatologist a comprehensive view of the entire operating field conferring visible endpoints for the radical removal of fistulas.