Since Albert Einstein theorized the concept of lasers in 1916, considerable development has resulted in an array of equipment available to the human and veterinary surgeon. The term LASER stands for “light amplification by the stimulated emission of radiation” and relies upon the production of electromagnetic radiation in response to photon emission by the lasing medium. The characteristics of a laser are directly attributed to the lasing medium. A class IV gallium-aluminum-arsenide diode laser creates a wavelength in the range of 790–830 nm, which is transmitted from laser unit to surgical site by a solid quartz-core, fiber-optic cable. A visible light beam is combined with the invisible laser beam to facilitate aiming. Laser fibers come in a variety of sizes (400–1000 µm) and shapes, including flat, conical, or orb tips. The fibers may be used through the instrument channel of a variety of rigid and flexible endoscopes, or in hand-pieces for open surgical use. Operator safety necessitates the use of protective glasses by all personnel.
The diode laser (Diomed, Inc., Boston, MA, USA) can be used in direct contact with tissue (contact mode) or at a distance from tissue (non-contact mode). In contact mode, the fiber tip is coated with a thin layer of carbon, which is heated as it absorbs laser energy. The heated tip can then be used to incise, excise, and coagulate tissue resulting in a 300–600 µm zone of thermocoagulation, which provides excellent hemostasis of vessels up to 2 mm in diameter. In non-contact mode, the laser is aimed at the tissue from a short distance. The degree of tissue penetration, coagulation, and vaporization depends upon laser power, duration of exposure, and tissue characteristic, particularly pigmentation.
The diode laser has been successfully used for various procedures in reptiles and amphibians including coeliotomy, ovariosalpingectomy, orchidectomy, cystotomy, enterotomy, abscess excision, tail/limb/digit amputation, oral surgery, enucleation and transendoscopic ablation of lesions within the respiratory tract and coelom. For general surgery, the 1000 µm fibers are preferred, but when performing microsurgery or endosurgery the 400–600 µm fibers with microconical tips provide greater accuracy and finer control. These procedures were performed using power settings between 3.5 and 7.5 watts.
Examples of these procedures are described to illustrate the versatility of the diode laser in herpetologic surgery and, as trials continue, it is expected that the indications for such techniques will increase.
The authors would like to thank the staff at the Exotic Animal Centre (UK) and the Eastern Exotic Veterinary Center (USA) for their assistance. Thanks also to Linda Madsen (Diomed, Inc.), Peter Brunelli (Universal Medical Systems, Inc.), Robert Young (Vet Alliance), Dr. David Sobel (Metropolitan Veterinary Consultants) and Dr. Christopher Chamness (Karl Storz Veterinary Endoscopy, Inc.) for their technical support.