Histological Comparison of 1064 nm Nd:YAG and 1320 nm Nd:YAG Laser Lipolysis Using an ex vivo Model

Background: Body contouring with liposuction including laser liposuction is one of the most commonly performed cosmetic procedures. Laser lipolysis is generally well tolerated with high patient satisfaction rates. Laser lipoplasty has been postulated to offer the unique advantage of skin tightening following removal of subcutaneous fat. The search continues for an optimal wavelength that would allow for: (1) efficient targeting of adipocytes while targeting dermal collagen and collagen bound water to allow for dermal remodeling and (2) targeting hemoglobin and vessel wall collagen to decrease intra-operative bleeding and consequent post-operative bruising. Objective: The main objective of this study was to determine the effects of 1064 nm and 1320 nm Nd:YAG lipolysis on fresh ex vivo human abdominal fat pads. Materials & Methods: Ipsilateral 1064 nm Nd:YAG lipolysis and contralateral 1320 nm Nd:YAG lipolysis were performed on ex vivo human abdominal fat pads from comparable topographic areas of the body of the same patient. Biopsy specimens were assessed for alterations of the epidermis, papillary and reticular dermis and subcutaneous fat. Conclusion: Our histological analysis demonstrated a wavelength dependent differential dermal response. Increasing fluence led to progressively more extensive dermal coagulation with associated epidermal thermal injury with 1320 nm Nd:YAG leading to more extensive collagen coagulation as compared to 1064 nm Nd:YAG.