Open their mouths and open your eyes

By Noel Berger, DVM, MS, Dipl. ABLS For The Education Center

Originally published in Veterinary Practice News, June 2014 – Download as a PDF

The mouth is a highly vascularized and innervated orifice. An entire subdiscipline of veterinary medicine specializes in its care. With some basic exploratory skills any practitioner can have a zesty taste of the rewards earned by discovering success in oral surgery using a CO₂ laser.

Originally utilized in gynecological applications, this laser has found favor with dentists and soft tissue surgeons alike because this laser wavelength (10,600 nm) is highly absorbed by water in tissue and its ability to produce ablation and/or hemostasis does not depend on intracellular pigments.^[1-3]

Even a simple surgical procedure in the mouth, such as obtaining a tissue sample for biopsy, involves bleeding, suturing, pain, swelling, possible complications, etc., which often discourages veterinarians from performing it. Instead, to obtain a histopathologic diagnosis, they may prefer to turn to a local surgeon or dentist to perform the procedure.

The presence of the laser in your practice can reverse that loss of professional activity. You can do this procedure and discover increased personal satisfaction, a greater sense of professional accomplishment and easily achieve higher wages.

Concurrently, clients will respect your abilities, save money and feel more comfortable remaining at their familiar veterinarian’s practice. The patient will experience less bleeding, less swelling and reduced or no pain as a result of laser surgery.

Before you can sample all of the good things you can do with a CO₂ laser in the mouth, there are a few safety precautions to follow:

• It is essential to have excellent lighting. Without good visibility you cannot work properly. A head loupe, a finger light or a focused spotlight should be used, or even a short rigid endoscope, if necessary.
• There must be adequate smoke evacuation. Throughout the surgery, vaporized particles are produced that are potentially carcinogenic and also primary respiratory tract irritants.
• All surgical personnel should wear special masks with 0.1 μm pores to prevent inadvertent inhalation of smoke particles.
• It is important to protect the endotracheal tube. Generally, moving it out of the way and covering it with wet gauze is sufficient to prevent ignition of gases.
• The patient’s teeth must be protected from laser energy, as it might permanently damage the enamel. Stray laser irradiation of the teeth must be avoided.
• A variety of long-reaching hand instruments and laser accessories to facilitate working in the oropharynx should be readily available.
• All personnel must wear personal protective eye goggles, minimum OD5. It is also very appropriate to protect the patient’s eyes with a suitable laser shield.

Surgical CO₂ lasers from Aesculight feature highly ergonomic flexible fiber with sterilizable handpieces, and a low-maintenance durable all-metal laser resonator. The list below demonstrates some of the most common procedures that can be done in the oropharynx.

Tongue Lesions

The cat’s tongue is essential for grooming, and it is dynamically intertwined with its personality and behavior. Unlike dogs, which will re-learn to eat and drink, cats will not accept a loss of tongue function.

Figure 1a shows a very painful lesion on the paramedian tip of the tongue. The cat was in pain, drooling, depressed, and refused to eat or drink. Under general anesthesia, the diseased portion of the tongue was removed in full thickness using the laser at 15W, continuous wave (CW) and with the 0.8 mm laser beam spot.

To finish the job and caramelize the surface, I used a wide nozzle tip, 4W laser power, CW (see Figure 1b). The procedure took less than one minute to accomplish. There was no bleeding and sutures were not required. Upon recovery, the cat was able to eat and drink normally, and importantly, resumed grooming instantly without complication.

Papillomas on the Lips

Figures 2a and 2b demonstrate a case of papilloma removal. The dog presented with numerous papillomas on the lips. The owner felt that the lesions were growing, and had become unsightly and unhygienic.

It was relatively easy to target the base of the lesions and achieve clean margins using the laser at 15W CW with the 0.4 mm laser beam spot. No suturing was necessary and the dog experienced no discomfort following anesthetic recovery.

Epulis and Gingival Hyperplasia

Because the oral cavity is highly vascularized, rich in mucous membranes and possesses an abundant nervous supply, the use of the laser in this area to cut and ablate tissue is truly remarkable.

Most oral procedures performed in the mouth are bloody and painful unless a CO₂ laser is used. With the laser, capillaries are sealed and small nerve endings are capped, providing a dry and pain-free surgical experience. After oral laser surgery, less post-operative pain medication is required and, as mentioned above, many times suturing is not necessary.

To protect the teeth, I insert a flattened non-reflective backstop between the hyperplastic gingiva and the base of the tooth crown (Figure 3a). When excising an epulis, I generally use the 0.4 mm laser tip and 10W CW power to achieve higher power densities; when removing gingival hyperplasia I use the 0.8 mm laser tip and 15W CW power to create a larger tissue kerf.

In both cases, an angled handpiece (shown in Figure 3a) is useful when working in the mouth as it keeps the laser beam perpendicular to the target tissue site.

Soft Palate and Tonsil

My previous publication in Veterinary Practice News covered the CO₂ laser-assisted uvular palatoplasty.^[4] Many brachycephalic feline breeds, such as Himalayan, Persian, etc., have some compromise to upper airway flow. The obstructed laryngeal airway, however, presents a bigger health concern for brachycephalic dogs, e.g., Old English bulldog, pug, Pekingese, shih-tzu, lhasa apso, Boston terrier and so on.

In dogs with this condition, the uvula is examined under sedation; if it is thickened and overlaps the epiglottis, it may be excised back to a level that approximates the caudal pole of the tonsils—as demonstrated in Figures 4a and 4b. Many patients also have profound tonsillar hyperplasia, and the laser (see Figure 5) is ideal for removing the glands as well as the redundant uvular tissue.

The excess tissue removal without postoperative pain or bleeding is achieved at high laser power of 15-20W CW with the 0.8 tip and is done in a single pass. No closure is needed. Most dogs breathe with no respiratory effort and less stridor immediately after the surgery. All of my patients are usually eating and drinking normally following complete anesthetic recovery.^[1]

Pharyngeal Saccules

Laryngeal web formation generally occurs as a sequel to attempted surgical devocalization in the dog. Unfortunately, in some cases the excessive amount of scar tissue that forms across the ventral aspects of the vocalis muscles can be life-threatening as it reduces the functional diameter of the laryngeal meatus.

Similarly, in some brachycephalic breeds that suffer from end-stage upper airway stenosis, the pharyngeal saccules may evert as an end-stage phenomenon due to increased straining to breathe and the chronic experience of negative pressure in the region.

In both cases, ablation of the fibrous connective tissue is easily achieved at relatively low power (5-10W, CW, 0.8 mm spot size), which allows the surgeon to see clearly due to lack of bleeding, vaporize the undesired tissue, and to do so with a minimum of discomfort to the patient.

Summary

The procedures briefly described here are common and require only basic training to be accomplished successfully. Using a CO₂ laser will empower the veterinarian to perform procedures in the mouth that s/he may have previously felt reluctant to take on.

Not every oral surgery requires a specialist. The use of a CO₂ laser and accessories in the veterinary practice enables veterinarians to successfully perform soft tissue surgeries of the mouth instead of referring them out. The necessary training is available at many organized conferences or by appointment with an Aesculight laser consultant. There are also continuing education wet labs as well as online courses and numerous other educational opportunities.

About the Author

Dr. Berger is a graduate of Cornell University (1988) for both his DVM and MS in clinical sciences. He is certified by the American Board of Laser Surgery in veterinary surgery and has written a textbook on the subject. He is the owner of the Animal Hospital and Laser Center of South Carolina, Pawleys Island. He lectures frequently on laser physics and clinical applications for small animal veterinarians, and is available for consultation and training.

This Education Center article was underwritten by Aesculight of Bothell, Wash., manufacturer of the only American-made CO₂ laser.

References

1. Berger NA, Eeg PH. Veterinary laser surgery: a practical guide, ed.1, Ames, IA: Blackwell Publishing, 2006.
2. Lopez N. Using CO₂ Lasers to Perform Elective Surgical Procedures. Veterinary Medicine. April 2002;97(4):302-12.
3. Bartels K, et al. Evaluation of carbon dioxide laser and conventional incision techniques for resection of soft palates in brachycephalic dogs. JAVMA 2001 Sep;219(6):776-81.
4. Berger NA. CO₂ lasers useful every day for every surgeon. Veterinary Practice News, December 2012:28-9.