by Arnold Plotnick MS, DVM, ACVIM, ABVP

For over 30 years, surgical lasers have been used in the field of human medicine.  Lasers have also been available to veterinarians for many years, but it is only in the past four years that the use of surgical lasers in veterinary medicine has gained widespread acceptance.  These commercially available carbon dioxide lasers are now being utilized by general practitioners to perform many elective procedures in cats, such as removal of skin masses, neutering, spaying, and declawing.

What are the advantages of laser surgery vs. traditional surgery?  Laser surgery causes less post-operative pain, less bleeding, and less swelling.  The disadvantages?  The cost: at the moment, laser surgical units are quite expensive.  Veterinarians must learn basic laser physics and safety, and learn to manipulate the laser efficiently and effectively.  Fortunately, because the laser can be used daily in general practice, the learning curve is short.  It doesn’t take long to develop the skill required to hold and guide the laser, and once mastered, the potential benefits of laser surgery are remarkable.

Most lasers used in small animal surgery utilize carbon dioxide.  Electrical energy stimulates carbon dioxide which causes it to emit a laser beam of light.  Soft tissue, when hit with this laser beam, absorbs the energy of the beam.  The energy is rapidly converted into heat.  The heat boils the water in the cell.  The steam produced causes the cell to break apart.  This results in an incision that is cleaner, as the laser coagulates and seals small blood vessels that are less than half the diameter of the laser beam, providing moderate control of bleeding.  Lymphatic vessels are sealed as well, resulting in less swelling at the surgical site.  Small nerve endings are also sealed, resulting in less postoperative pain. 

Use of the laser requires training, both in surgical technique as well as in safety precautions so that the patient, the staff, and the surgeon are protected from injury.  The Occupational Safety and Health Administration (OSHA) has published requirements on laser safety protocols, requiring a veterinary staff member to be a designated laser safety officer (LSO), and the American National Standards Institute has published guidelines regarding laser safety (ANSI Z1363, Safe Use of Lasers in Health Care Facilities) which should be required reading by veterinarians using surgical lasers.  A smoke evacuation system is necessary to remove the plume of smoke that results when the laser beam contacts the tissue.  The laser plume, which is mostly water vapor, has also been shown to contain inorganic compounds such as carbon monoxide and other sulfur compounds, organic compounds such as cyanide and formaldehyde, and microorganisms such as bacteria, fungi, and viruses.  Special masks (with very fine pores) must be worn by all personnel in the vicinity, to avoid inhaling any of these substances that may be missed by the smoke evacuator.  In addition to masks, everyone near the surgery room must wear special goggles or eyewear, as direct or indirect laser light can cause permanent eye damage.  The animal undergoing the procedure must also have its eyes protected from stray laser beams.  Potential reflection from surgical instruments must be avoided, and one must take care not to use flammable anesthetic gases or accidentally make a laser incision into the endotracheal tube.

The most common laser procedures performed on cats include neutering, spaying, de-clawing, and skin mass removal.  Using the laser for feline castration results in less patient discomfort and reduced bleeding.  When the laser is used to transect the testicular artery, vein, and vas deferens, the vessels and nerves are sealed immediately, resulting in no bleeding, and no pain.  Spaying with the laser has similar advantages – diminished bleeding, swelling, and pain – however, as with any surgery in which the abdomen is opened, internal organs such as the liver, spleen, bladder, intestines, etc. must not be hit with the laser, or inadvertent vaporization may result.  Skin mass removal is easily accomplished with the laser.  Removal of highly vascularized skin tumors in the traditional fashion often requires a considerable amount of time, most of which is spent controlling bleeding from vessels in the mass.  Lasers, by sealing blood vessels as they cut the skin, provide unprecedented speed when removing skin masses.  Small masses (less than 5 millimeters in diameter), such as warts, do not need to be removed and sutured using the laser.  Using a 0.8 mm laser tip and a continuous stream of laser energy, small masses can be ablated (burned away).  The remaining defect, rather than be sutured, can be mildly charred using a less intense beam, with the charred tissue serving as a “bandage”.  An antibiotic ointment applied to the site keeps the tissue moist, and results in rapid healing. Lasers are also useful in managing contaminated wounds, as bacteria, fungi, and viruses are vaporized by the carbon dioxide laser, effectively disinfecting the tissue.

Feline onychectomy (declawing) is a procedure that is still viewed with controversy by cat owners, breeders, and veterinarians.  The carbon dioxide laser, when used in declawing, is said to reduce post-op pain, bleeding, and swelling.  Cats, as a result, return to their normal activity more rapidly.  The technique requires training and practice.  Excessive, inadvertent lasing of tissues can cause undue heating of tissues, resulting in pain and swelling post-operatively.  Unlike conventional declawing, bandaging the feet is not required when using the laser for the procedure.  A recent report in the September 1^st, 2002 issue of the Journal of the AVMA entitled “Use of Carbon Dioxide Laser for Onychectomy in Cats” compared postoperative signs of discomfort and complications in cats de-clawed with the laser vs. those de-clawed conventionally (with a scalpel).  The study concluded that neither technique resulted in high discomfort or complications, although the laser treated group had lower scores for signs of discomfort and complication on the day after surgery.  On the seventh day after surgery, there were no significant differences between laser-de-clawed cats and conventionally de-clawed cats. 

As laser surgery gains wider acceptance, the price of the surgical unit is certain to drop, becoming affordable for many general practitioners.  Recognizing that laser surgery would rapidly grown in popularity, The Veterinary Surgical Laser Society (VSLS) was formed in 1999 to help guide veterinarians seeking to develop knowledge and expertise in this field.  The VSLS sponsors continuing education courses in the use of lasers.    Refinements in the equipment are bound to make it easier to use, improving the surgical outcome for many feline patients.

Updated 2/9/06