March 22, 2012
Fourteen years ago, when cell phones resembled barbells and personal computers were still an option, Kenneth Bartels was hunkered down in the heart of Oklahoma State University’s veterinary teaching hospital, becoming an expert on an extraordinary technology that now literally is veterinary surgery’s cutting edge: carbon dioxide and diode lasers.
“Laser surgery is noted for an ability to minimize hemorrhage and seal nerves and lymphatics through photothermal activity,” said Bartels, DVM, director of the Surgical Laser Laboratory at OSU’s Center for Veterinary Health Sciences. “This implies there is decreased inflammation and less pain. The surgical laser is a tool that can be used to great advantage with the appropriate understanding and training.”
And the education is out there: Dr. Bartels said laser theory is now incorporated into Oklahoma State University's veterinary clinical curriculum, along with wet labs for student chapters of the American Animal Hospital Association and American Association of Feline Practitioners.
For small-animal surgery, carbon dioxide lasers are used in cat onychectomies, several phases of brachycephalic airway syndrome surgeries, spays and neuters, tumor removals and surface incisions. In equine medicine, the fiber-delivered diode laser is used with an endoscope to visualize and treat upper respiratory and urogenital problems.
Animal-rights groups notwithstanding, declaw surgeries remain a facet of small-animal veterinary practice for the foreseeable future. The CO2 laser offers advantages to practitioner and patient.
“The laser will cauterize small blood vessels as it cuts, and therefore you will have minimal hemorrhage,” said Kathleen Ham, DVM, assistant professor of small-animal surgery at The Ohio State University College of Veterinary Medicine. “This also means that you don’t really need to use a tourniquet, which would, in turn, reduce any risk of neuropraxia as a result of improper or too-long use.”
Ham, a diplomate of the American College of Veterinary Surgeons (ACVS), noted that the laser method shortens surgery time, because reduced bleeding makes the incision line easier to see and to close.
“Most people don’t use a bandage after a CO2 laser declaw,” she said.
Best of all, a laser declaw appears to be less painful than a scalpel declaw. Dr. Ham cited a study comparing the two methods which found “The CO2 laser group seemed more comfortable the first day post-operatively. This is because the laser will vaporize small nerve endings, which produces a seal over the nerve, resulting in decreased action potentials,” she said. “Another study found that cats will bear more weight one and two days post-operatively after a CO2 laser declaw, versus a scalpel declaw.”
Safety Training a Must with Surgical Lasers
“Lasers can ignite things, so certain precautions must be used,” noted Kathleen Ham, DVM, assistant professor of small-animal surgery at The Ohio State University College of Veterinary Medicine. “All sponges and drapes that are immediately in the field should be moist. Alcohol-based solutions should be avoided.”
Dr. Ham said commonly used endotracheal tubes are flammable if exposed to lasers, but laser-specific tubes are available. Alternatively, some practitioners cover a conventional tube with moistened gauze if it is near the laser field.
“Oxygen is flammable, so extra care must be taken during airway surgery, as an airway fire could be life-threatening,” she said. “Methane is also flammable, and colorectal surgeries need certain precautions.”
Like anything else worth doing, practice brings proficiency, according to surgical pros.
“There is definitely a learning curve for using a laser, as it takes precision and coordination,” said Ham, a diplomate of the American College of Veterinary Surgeons. “Veterinarians who are already efficient at surgery using a scalpel can be trained to use a laser.”
“A theoretical knowledge of how the laser works, and to which tissues different types are best used, is obviously required,” said Nicola Cribb, DVSc, assistant professor in large-animal surgery at the University of Guelph, Canada, Ontario Veterinary College. “The actual ‘doing’ of upper respiratory surgeries takes some practice and, as with most surgeries, having tips and tricks passed on from an expert in the field greatly assists in learning how to do these surgeries in a timely manner.”
In the hands of the inexperienced, laser technology poses risks to the patient. Dr. Cribb, an ACVS diplomate, noted that a number of important nerves and nerve endings lie in close proximity to the respiratory surgical field.
“It is not a simple tool of ‘What you see is what you get,’” said Eric Parente, DVM, associate professor of surgery at the University of Pennsylvania’s New Bolton Center. “If it’s used excessively, thermal injury can cause collateral and possibly irreversible damage.”
Added Ham, “If the laser contacts the skin inadvertently, it can cause blistering and erythema on incisions.”
Guidelines for safe use of lasers in health care, both human and veterinary, are governed by the American National Standards Institute, said Kenneth Bartels, DVM, director of the Surgical Laser Laboratory at Oklahoma State University’s Center for Veterinary Health Sciences.
The guide was updated and published this year by the Laser Institute of America, he said, and is the definitive resource for training and safety.
For example, signs must be posted during laser use, and protective eyewear and laser-safe surgical masks must be worn, said Dr. Bartels, who is the American Veterinary Medical Association’s representative to the institute’s Committee for Laser Safety in Medical Facilities.
“An aberrant beam can be dangerous, which includes the potential for fire,” he said. “Safety training needs to be emphasized by the laser manufacturer.”—LAM
Then there are the bulldogs—gotta love ’em, and many people do. Laser surgery is used for such brachycephalic surgical applications as elongated soft palate, stenotic nares and excision of everted laryngeal saccules.
“The CO2 laser can also be used to ablate tissue, for instance with perianal fistulas or in some oral surgeries,” Ham said.
CO2 laser technology also comes into play for ear surgeries, including biopsies, pinnectomies, aural hematoma repair and ear canal resections.
Bartels, a fellow of the American Society of Laser Medicine and Surgery, explained that a CO2 laser’s energy is very highly absorbed in water, making it ideal for incisional applications.
“But there are limitations in application, since the energy is delivered through an articulated arm of a hollow, flexible wave guide,” he said. In comparison, diode surgical lasers are fiber-delivered and can be used for minimally invasive procedures through an endoscope.
A third type of laser, Holmium:YAG, can be used endoscopically or through myelographic needles, for vertebral disc ablation. Lithotripsy of urinary calculi can be accomplished using a Ho:YAG laser.
“Diode lasers are a bit more complicated to use, due to their wavelength and tissue interaction characteristics, which must be understood,” Bartels said, noting that these fiber-delivered lasers may be more appropriate for equine or mixed-animal practices.
At Cummings School of Veterinary Medicine at Tufts University, laser technology is in high demand for respiratory surgeries in race horses, said Jose Garcia-Lopez, VMD. Calling it “the bread and butter” of surgical methods, the associate professor of large animal surgery said the technology is invaluable for laryngeal procedures on epiglottic entrapments, upper airway cysts, hemiplegia and flaccidity of the vocal folds.
Transendoscopic laser surgery of the upper respiratory tract is performed without a skin incision and can be done with the horse standing with sedation and a local anesthetic, often on an outpatient basis, according to Eric Parente, DVM, associate professor of surgery at the University of Pennsylvania’s New Bolton Center.
“The laser fiber is passed down the biopsy channel of the endoscope, thus getting to areas of the throat that would otherwise be difficult to get to, and it provides great visualization,” said Dr. Parente, an ACVS diplomate.
Dr. Garcia-Lopez, also an ACVS diplomate, said laser technology is used at Tufts to manage varicose veins and endometrial cysts in multiparous mares, and “a lot of us use the CO2 lasers for neurectomies on the palmar digital nerves“ of the foot. “We find that use of the laser, rather than a scalpel, to cut the nerve allows the nerve endings to heal better, and there’s less chance of neuroma formation.”
The veterinarians interviewed for this story happen to practice in academic hospitals, but surgical lasers, especially CO2 lasers, have also been adopted in private practice.
“I first began using it for declaw and spay/neuter procedures in a private practice,” Ham said. “I then used it occasionally for brachycephalic airway surgeries and perianal surgeries.”
“For equine,” Parente noted “there are some larger private practices that function similarly as referral surgical facilities, but it would not be used as a surgical instrument by a field practitioner since their focus is not on surgery.”
Bartels has published more than 75 articles, written seven book chapters, and a book involving surgery and the use of lasers in both animals and people.
“Using a surgical laser in a practice is an economic decision as well as a decision to take a step higher using available medical technology,” he said. “It is well worth the time and financial commitment to attend continuing education venues offered at a number of national and regional veterinary meetings. Once a veterinarian is convinced a surgical laser is an appropriate investment, asking for demonstrations from multiple vendors is a good idea.”
Dr. Epperley is an associate veterinarian for Southern Agriculture Inc. in Tulsa, Okla. Before earning her DVM from Oklahoma State University in 1999, she worked as a journalist in Oklahoma City, covering business and political news.
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