In Vivo and Ex Vivo Skin Reactions after Multiple Pulses of 1,064-nm, Microlens Array-type, Picosecond Laser Treatment

Polydeoxyribonucleotide and Microlens Array-type, Nanosecond-domain Neodymium:Yttrium-aluminum-garnet Laser Treatment for Scars from Costal Cartilage Harvest Surgery: Case Series of 9 Patients

“…10 Moreover, multiple stacking pulses of MLA-type, picosecond-domain laser treatment has been found to generate marked TI-LIOB reactions in the epidermis and remarkably large areas of thermal coagulation in the mid to deep dermis of ex vivo brown micropig skin. 7 While multiple non-stacking pulses of MLA-type laser treatment produced more homogeneous, numerous microscopic vacuoles and pseudo-cystic cavities in the epidermis and upper dermis, compared with stacking pulses, large areas of dermal coagulation could not be found. 7 A pattern analysis study using tissue-mimicking phantom revealed that nanosecond-domain laser treatments effectively fragmented imbedded tattoo particles into smaller ones, albeit more coarsely disintegrated, than picosecond-domain laser treatments at similar treatment settings.…”

“…7 While multiple non-stacking pulses of MLA-type laser treatment produced more homogeneous, numerous microscopic vacuoles and pseudo-cystic cavities in the epidermis and upper dermis, compared with stacking pulses, large areas of dermal coagulation could not be found. 7 A pattern analysis study using tissue-mimicking phantom revealed that nanosecond-domain laser treatments effectively fragmented imbedded tattoo particles into smaller ones, albeit more coarsely disintegrated, than picosecond-domain laser treatments at similar treatment settings. 9 Nonetheless, nanosecond-domain laser treatments reduced the risk of photomechanical damage to the surrounding tissues, and photomechanical reactions were found to be stabilized earlier with nanoseconddomain lasers than with picosecond-domain lasers.…”

“…10 Accordingly, MLAtype Nd:YAG lasers have been suggested to be of use for various clinical purposes, including skin rejuvenation, atrophic scars, enlarged pores, and pigmentary disorders, depending on the treatment parameters. [6][7][8][9][10][11] Picosecond-domain lasers have been shown to elicit notably greater photomechanical effects on target tissue than nanosecond-domain lasers. 9,10 A previous ex vivo pigmented micropig study demonstrated that picosecond-domain laser irradiation results in larger and more microscopic vacuoles and pseudo-cystic cavities in the epidermis and upper dermis than nanosecond-laser irradiation at similar treatment settings, including the type of beam (flat-top beam), wavelength (532 nm and 1,064 nm), and number of pulses.…”

“…4,5 Laser energy, which is delivered through fractionated optics, generates fractionated high-fluenced areas in the epidermis and upper dermis with surrounding low-fluenced areas. [4][5][6][7] In these treated areas, histopathologic features of thermally-initiated laser-induced optical breakdown (TI-LIOB) with microscopic vacuoles and pseudo-cystic cavities of various sizes are visible. [4][5][6][7][8] In this report, we retrospectively reviewed 9 patients with postoperative scars after costal cartilage harvest surgery for revision septorhinoplasty.…”

“…[4][5][6][7] In these treated areas, histopathologic features of thermally-initiated laser-induced optical breakdown (TI-LIOB) with microscopic vacuoles and pseudo-cystic cavities of various sizes are visible. [4][5][6][7][8] In this report, we retrospectively reviewed 9 patients with postoperative scars after costal cartilage harvest surgery for revision septorhinoplasty. Most of the scars clinically presented with eosinophilic, atrophic, and fibrotic features with various degrees of dyschromia.…”