Article © 2000 Darlene Arden. First published in DOG World, September 2000.
Lasers Lead Surgery to the Cutting Edge
Veterinarians have gone high-tech to heal dogs more quickly and with less pain.
Bretton, a 12 year old Cardigan Corgi takes a break. Photo Lisa Croft-Elliott
If your dog sounds like it's snoring when it's wide awake, a common occurrence if it's brachycephalic (short-faced like a Pug or Bulldog), it probably has an elongated soft palate. Although the condition has the potential to lead to pulmonary and/or cardiovascular problems, most owners simply have come to accept the sound as part of owning a short-faced breed.
Now, with the advent of laser surgery, the soft palate (the structure at the back of the throat) can be shortened with very little trauma, alleviating the condition. This is just one of the many exciting applications of the laser in medicine. Although lasers have been in use in human medicine for some time, they are now at the cutting edge of veterinary technology.
The Lure of Laser
At the forefront of the veterinary laser surgery movement is Kenneth Bartels, D.V.M., M.S., the McCasland Foundation Professor of Laser Surgery and the Cohn Chair for Animal Care in the Department of Veterinary Clinical Sciences at Oklahoma State University College of Veterinary Medicine in Stillwater, Okla.
"Applications of laser energy in dogs have included vaporization of oral and skin tumors, and other techniques where the laser can be used as a virtual bloodless scalpel," Bartels says.
Other techniques in canines include the use of laser energy to eliminate intervertebral discs in dogs with back problems, perform selective treatment of cancer using a technique called Photodynamic Therapy, and the breakdown, or lithotripsy, of urologic calculi, or stones.
Bartels describes laser light as monochromatic, or one color, and it is collimated--in other words, extremely focused--into powerful beams.
"The color of laser light or wavelength determines how it reacts with tissue," Bartels explains. "Lasers are made of components that can be very different from each other. One type of laser may react most with water in tissues while another may 'see through' the water and concentrate its energy in the hemoglobin of blood. Laser energy usually creates a photothermal, or heat, reaction with tissues. It can virtually vaporize tissue at the speed of light and at the same time, seal blood vessels, lymphatics and nerves."
Lasers produce a type of light energy that is both powerful and concentrated. "Some lasers can also be used through fiberoptic delivery systems for minimally invasive surgery through endoscopes," Bartels says. "If you can see it with a scope, you can vaporize it."
The biomedical laser first was used in veterinary medicine in the late 1970s. During the mid-1980s, a small group of vets began to meet and discuss applications of lasers in veterinary medicine. Early users of the laser included veterinarians from North Carolina State University, the University of Pennsylvania, the Universities of California at Irvine and Davis, and Oklahoma State University.
"University participation was essential since many of the devices were very expensive and somewhat difficult to operate," Bartels recalls. He also remembers those early lasers as being very large, cumbersome and costly to maintain.
"In addition, a few private practitioners were on the leading edge of the technology," Bartels says. "The surprising fact is that veterinary practitioners have become very involved in the transfer of this new technology to their clinics. With the combined interest of a few companies [ESC Medical Systems/Luxar and Ceramoptec] that have produced and marketed smaller and relatively economical devices, over 700 lasers are currently in use in private practices." Although most colleges of veterinary medicine now have access to the technology, some have not yet acquired lasers for clinical use.
William Young, D.V.M., owner of Chevington Animal Hospital in Pickerington, Ohio, strives to offer his patients the highest level of technology available. He has been interested in laser surgery for about five years but intensified his interest over the last three years.
BleuJoie's U-R-Morgan, bred by Jaye Clarke
Photo by Sandra R. Noe
"I utilize my CO2 surgical laser whenever it is appropriate," Young says. "This may mean that I turn it on several times a day. The CO2 laser has its limitations and should be used only for thee benefit of the patient. It is not appropriate for use in every case." Young tends to shy away from using the CO2 laser in invasive or particularly bloody procedures because it takes longer for laser incisions to heal.
Tumor removal is the most commonly performed canine laser procedure in Young's practice. "[The laser] eliminates much of the post-surgical swelling and pain," Young says. "I use the laser in many other procedures such as castrations, periodontics, oral surgery, ear surgery, ophthalmic surgery, rectal surgery and many other cases that benefit from the inherent characteristics of the CO2 laser."
Rick Wall, D.V.M., who owns the Animal Clinic at Alden Bridge in The Woodlands, Texas, is another veterinarian who, wanting to maintain a progressive practice, began performing laser surgery three years ago. Wall does approximately 25 anesthetic procedures every week, using the laser in as many as 30 percent of them.
He also uses it for removing small tumors, masses, dermal warts and cysts. With older patients in whom there is a concern about anesthesia, Wall finds he can remove small warts or cysts using the laser and a local anesthetic, sometimes adding a little sedative, while the owner holds the dog.
Malignant tumors that often occur underneath the skin or in subcutaneous tissues, or tumors in which malignancy is suspected, not only can be removed with the laser but the surgeon also may use the laser to treat the surrounding tissue.
Going Under the Light
Through the use of the laser, veterinarians are finding the old ways aren't the only ways of performing surgery anymore. For example, the laser allows Wall to do a slightly different neutering procedure than traditionally has been performed, making a very tiny incision over the scrotum, an area he was told in veterinary school not to cut because it can cause swelling. He hasn't run into that problem when using the laser. He removes the testicles, then ligates blood vessels as he always did before using a few drops of surgical adhesive glue to close the skin. The incision on most dogs is anywhere from three-eighths of an inch on smaller dogs to about three-quarters of an inch on large canines.
"It takes me about five minutes to perform the procedure, and these dogs go home the same day," Wall says. "We've not had any dogs bother these incision sites. It is sometimes difficult to see where we did the incision. It's just so quick and less painful."
Bartels agrees. "Laser surgery does offer some benefits in reducing hemorrhage at the surgical site and by sealing lymphatics and some nerves," he explains. "This means there may be less inflammation and pain. Laser incisions heal a bit slower than do conventional scalpel incisions. However, by 14 to 21 days, the laser incisions are healed and just as strong as are scalpel incisions."
The laser also is effective in oral surgeries, removing rather large tumors or masses.
"The CO2 surgical laser allows the surgeon to successfully work routinely in areas that are normally very difficult to operate in," Young says. "For instance, I have removed several large tumors from the tongue and pharyngeal areas that normally could not be removed without great risk to the patient. These turned out to be bloodless surgeries. The use of 'cold steel' [scalpels] surgery in these areas is historically difficult and fraught with the complications of bleeding and swelling."
|Leeside Storm Warning, "Stormy" . Photo Diane Smith
Some oral tumors are extremely aggressive and don't respond very well to traditional therapy or surgery. "By no means am I saying that [laser surgery] is a cure, but some of these patients will present not eating well, they can't breathe well and when you can debulk or remove the majority of the tumor with the laser, you improve the quality of their life for at least some period of time," Wall explains.
The procedure also can be utilized to perform debarking. Although Wall doesn't promote the surgery, if an owner has tried everything to curtail barking and it has reached the point where either the dog is debarked or the owner will get rid of the pet, he will debark the animal using the laser, going into the throat through a laryngotomy incision and removing the vocal cords, as opposed to performing the conventional devocalization through the mouth.
Another advantage of using the laser is that it limits the amount of trauma to the tissue being operated on. Wall likes using the laser to remove anal sacs for this reason. After using the laser to make a small incision over the sac, it then can be removed easily or vaporized. These are very sensitive tissues, and using the laser lowers the amount of post-operative pain medication and virtually eliminates the need for an Elizabethan collar.
In all of the anal sac surgeries he's done, only one dog required an Elizabethan collar to prevent it from bothering the surgical site. "For five days after [conventional] surgery, the client sometimes wished they hadn't had it done. We just don't see that with the laser," Wall explains.
"The inherent characteristics of the CO2 laser allow the laser surgeon to work more comfortably in highly vascular tissues," Young says. "The CO2 laser is exceedingly tissue-friendly. It works by vaporizing cells that are exposed to its high-energy beam. The CO2 laser beam is almost entirely absorbed by the intracellular water matrix. These molecules of water that absorb the energy of laser beam become highly excited. As the energy level of the water molecules increases, they begin to change their state of matter from a liquid to a gaseous form. When this change occurs the cellular architecture is rapidly expanded and the cell membrane explodes." The water becomes steam and is vaporized along with the rest of the contents of the cell.
"Collateral tissue damage is minimal due to the narrowly focused beam," Young adds. "The depth of penetration is shallow, about .5mm. Small blood and lymphatic vessels are sealed, minimizing bleeding and the release of noxious vasoactive agents that cause swelling and pain. Nerves are cut in the same manner further decreasing pain."
But reports of less pain could be a mixed blessing.
Golden Retrievers, Chip and CJ relax after a field trial. Photo by Joyce Jones
"This is both good and bad because an animal that has surgery needs to protect its surgery site," Bartels explains. "Animals usually do this by limiting their activity due to some postoperative pain. If there is minimal postoperative pain, the dog or cat may overdo their exercise and traumatize their surgery site."
Laser surgery also offers advantages to some surgical procedures that easily could be performed using a scalpel or an electrosurgery unit. "You can be very precise with a laser and minimize injury to adjacent tissues," Bartels explains. "In essence, you can be a bit more gentle when using a laser than with more conventional surgical techniques. The laser is still a surgical tool, however. It is not the answer to every surgical problem but can help the surgeon in many instances."
Aside from the reduction of pain and swelling, time is another factor: "If the surgery would normally have been time-consuming due to the amount of bleeding incurred, the laser actually may reduce surgical time and hence, reduces anesthetic risk," Young says.
Opening More Options
Along with the time factor, the laser's ability to seal blood vessels has made some surgeries possible that might not have been considered previously, "specifically, tumors or surgeries performed in highly vascular areas," Young says. "These surgeries can be impossibly bloody at times under normal conditions. The laser also affords the surgeon better visualization of abnormal tissues due to better homeostasis. Complete ablation [removal] of neoplastic tumors is easier due to this."
Young tells of an instance in which he removed a marble-sized sarcoma from the pharynx of a 6-pound Papillon. The tumor was blocking the dog's trachea, and surgery would have been virtually impossible to perform with conventional methods without putting the patient in danger. The laser not only allowed the complete removal of the sarcoma, but the patient suffered no adverse effects.
Wall recalls a Bulldog that suffered from a variety of problems, including dry eye, and had a huge corneal ulcer that wasn't healing. The dog couldn't be anesthetized due to its bad heart.
"I had talked to some other people who had been using the laser a little bit in the eye for corneal ulcerations," Wall says, "so we did a topical local anesthetic and lightly restrained him. Then I treated his eye with the laser." Wall debrided dead tissue from the cornea of the eye, and it healed quickly.
Despite his success with the Bulldog, Wall would like to see a university or an ophthalmologist do a study of laser use on the cornea because there are complications with using the CO2laser in the canine eye. But in this particular case the recommended procedure would have been having an ophthalmologist perform a conjunctival flap requiring anesthesia, which the dog couldn't have handled. The dog since has died, but its eye was fine for the last year of its life.
Wall is quick to point out that he's not promoting laser use on corneal ulcers: "We don't use it every time we have an ulceration in the eye. But I think in this particular case it made a difference when I couldn't have done anything otherwise."
Piper, the Yorkshire Terrier, sitting pretty.
Photo by Lynn Hoover
Wall is always looking for new applications for his laser. He recently employed the endoscope method with a 12-year-old Shetland Sheepdog that has transitional cell carcinoma of the bladder. Generally, by the time a dog presents with symptoms of this form of cancer, the prognosis isn't good. The Sheltie couldn't urinate, and an ultrasound revealed a huge tumor in the bladder.
The owners wanted to do everything possible to save the dog, so Wall resectioned the bladder and removed the entire tumor and as much of the margins as he could, then put the dog on chemotherapy. The dog was able to urinate again but began getting sick after three chemotherapy treatments. The owners decided to stop the chemotherapy. Follow-up ultrasounds showed the tumor beginning to grow back, but Wall didn't want to do another radical surgery on the bladder.
Previous biopsies did not show the tumor to be very invasive in the deeper structures of the bladder; it primarily was in the lining of the organ. So a decision was made to treat the inner lining of the bladder surgically. Making a small incision, he inserted a laproscope and then put a laser into the bladder. "We inflated the bladder with carbon dioxide and inserted the laser and scope, and we were able to vaporize that tumor with the laser without radical surgery," Wall says. "The dog went home that day and is doing great. We're following it along." Although there has been some regrowth of the tumor, Wall plans on performing the procedure again as needed.
"I wouldn't want to promote that we're curing transitional cell carcinoma," he adds. "It's just something that I can offer because of having the laser and some of the other equipment that I have, that I couldn't have offered without it."
The owners are happy because debulking the tumor improves the quality of the pet's life and is a better option than putting the dog to sleep. Wall rationalizes that there's no mental aspect to diseases such as this in animals--when the pain is removed, so is the discomfort, and the dog is happy.
For as many benefits as laser surgery is providing for veterinarians and their patients, nothing is perfect. But drawbacks to the use of lasers primarily are economic. "The cost of the devices are high, and this cost has to be passed on to the pet owner in some way," Bartels says. "The use of lasers has virtually exploded in the past two years in many veterinary practices."
According to Bartels, most lasers on the market for veterinarians cost between $20,000 to $50,000. "To pay for this technology, most practitioners will add a certain amount to each procedure for laser surgery," he says. "If both the veterinarian and the client can recognize the benefits of laser surgery, it's probably worth the additional cost per procedure. Today most veterinarians will add an additional $20 to $200 per procedure for laser surgery. Again, the amount depends on the procedure."
Wall hasn't raised his fee on some procedures, such as spay/neuter. "There's a minimal fee for what we call the laser prep, which is the little instrumentation tips and things like that," Wall says. "I think for the most part, most laser surgeries are going to be anywhere from 15 to 30 percent more expensive. But you also have to understand that there's some procedures that I don't think we can do without it, so it's not that the laser's more expensive, it's just that in my practice there are some that I wouldn't be doing."
Another question about the CO2 laser is one of the safety. Accidental reflection of the laser beam poses a hazard to the patient, surgeon, technicians and anyone else in the room. Smoke from the laser vaporization, electrical and fire safety are concerns.
"Although it's relatively easy to learn the techniques necessary to perform laser surgery, the safety aspects are essential for both the patient and doctor," Bartels points out. "Veterinarians do take this seriously, and most obtain the necessary training to use lasers safely and appropriately. They do not practice a 'burn and learn' technique."
Although the laser cuts down on blood loss and can make certain surgeries easier, it is at a distinct disadvantage to conventional surgery in at least one area.
"Contrary to popular belief, tissue exposed to a laser beam does not heal as fast as tissue cut by a scalpel," Young says. "There is a small thermal component exerted upon the tissues by a laser beam. This small thermal injury to the margins of the incision actually delays healing on a cellular level by about three days. We usually do not notice this because of the reduced swelling and inflammation at the surgical site."
Young admits there have been no comparative studies to support his claim. His conclusion, however, is based on his clinical observation of some 1,500 laser surgeries.
Other drawbacks to the procedure include the fact that lasers perform best on tissues with a high water content. Other tissues, such as bone or dense connective tissue, are far less affected by the laser beam.
"Nothing is without problems, and [lasers] shouldn't be promoted as such," Wall says. "We need a lot more education on the procedure. I think if there's any downside at all, it's probably the fact that as veterinarians we don't have the economical situation to have every piece of equipment we sometimes need, so we have to work around that."
Perhaps the most exciting aspect of laser surgery is that it still is a relatively new science. Bartels believes the uses for lasers in veterinary medicine will be boundless as technology improves and they become easier to acquire and use.
"Many more procedures using minimally invasive surgery are possible with laser energy," Bartels says. "More selective treatment of cancer and other types of pathology will be possible. Advanced techniques using lasers could also include laser tissues welding where sutures are no longer necessary."
Bartels even envisions a future in which lasers will be able to perform noninvasive diagnostic procedures such as determining values for kidney functions or blood sugar, and for determining whether a tissue is benign or malignant.
"I expect, as we become more proficient with its use and the technology continually improves, that the laser will be utilized more frequently," Young says. "This opens up a whole new field of noninvasive surgery. It could have applications as far-ranging as gastrointestinal and arthroscopic surgery."
According to Wall, the future is unlimited. "All [veterinarians] have to do is follow what they're doing in human medicine," he says. "It's just a matter of making it economical for us to do it, and making it feasible for us to do it. It's just a matter of when it gets to the point of where we can afford the equipment, the technology. And are the people willing to pay for it? I think in a lot of instances they are."
Wall says he is excited about the newer lasers that will allow for minimally invasive procedures and envisions himself purchasing more lasers in the future.
"I believe that with the objective use of lasers, the benefits reported will outweigh the perceived disadvantages [cost/safety issues]," Bartels says. "Within five years, most larger veterinary practices will acquire or have access to a surgical laser.
"It's important we look at this technology in an objective manner," Bartels adds. "It's not a gimmick or a marketing tool. Lasers can benefit veterinary medicine greatly if this wonderful tool is used to enhance our skill and knowledge."
"The future is now," Young says. "More and more veterinarians are comprehending the advantages of laser surgery. The single most important factor is that our patients benefit the most."
To this end, the Veterinary Surgical Laser Society was founded to enhance the understanding of lasers in veterinary medicine. The VSLS conducts meetings, discussions, video sessions and workshops to keep its members informed of the latest news and technologies available regarding lasers for veterinary medical and surgical applications.
Just a few short years ago, laser surgery sounded like something out of a science fiction movie. But it has quickly become a reality. Laser surgery has proved to be a viable, successful option for many procedures. This article is written, in fact, by someone who no longer needs to wear eyeglasses thanks to laser surgery, and who can attest to the singular lack of real post-surgical pain.
It's comforting to know that our beloved pets can enjoy the same sort of recovery. And procedures not previously available now also are a reality. If this is any indication--and it certainly should be--the future of lasers in veterinary medicine looks very bright indeed.