Surgical guidance
The final principal factor in incising tissue is guidance by the surgeon. Most veterinarians are experienced with scalpels.
Scalpels provide excellent tactile sensation through which you may increase or decrease pressure to change the depth of cut.
Within the limits of lateral resistance, you can move blades over, through, and around structures to make incisions. Lasers
provide no tactile sensation since their path is visually guided. Like a scalpel, radiosurgery provides a sense of tactile
sensation. And as with a laser, with radiosurgery there is an absence of tissue resistance. For this reason, some surgeons
consider the learning curve quicker and easier with radiosurgery than with lasers.1
Other factors to consider
To avoid postoperative complications, it is important to avoid damaging tissue that surrounds the incision. Steel scalpel
blades produce no lateral heat as they pass through tissue. The absence of lateral heat is an advantage in that no surrounding
tissue is altered, but it is also a disadvantage in that no hemostasis occurs. Lasers and radiosurgery generate lateral heat
to seal small vessels, nerve endings, and lymphatics as incisions are made. Radiosurgery electrodes of varying shapes and
different waveforms may be used to enhance hemostasis.
Several studies have been performed to examine the damage done to surrounding tissue by lateral heat transfer by radiosurgery
and carbon dioxide lasers.9-11 The tissue damage produced by radiosurgery when in the fully rectified modulated waveform mode is similar to that of a steel
scalpel, allowing comparable biopsy samples to be obtained that lack thermal or mechanical artifact.9 A study in people in which oviducts were incised with lasers (carbon dioxide, Nd:YAG, and KTP-532), electrocautery, and radio
frequency showed that radio frequency produced the least damage to surrounding tissue and carbon dioxide lasers produced the
second lowest amount of damage when compared with scalpel incisions.10 In another study, carbon dioxide lasers were compared with scalpels for resecting the soft palates of brachycephalic dogs.
Clinical outcomes were similar in dogs in which lasers or conventional scalpels were used, but surgical times were significantly
shorter when lasers were used.12 One surgeon has anecdotally noted that skin incisions made with radiosurgery heal as quickly as those made with a steel scalpel.1
Another factor is equipment cost. The cost of steel scalpel blades varies depending on their intended use, but for the most
part the scalpels are a negligible cost of surgery. Radio frequency surgery units are one-third to one-half the cost of lasers.3,13 Additionally, handpieces and electrodes for radio frequency surgery can be steam-autoclaved. One factor that is often not
considered is the space a unit occupies when not in use. While none of the mechanical methods of surgical incision compares
with the small size of a box of scalpel blades, radiosurgical units occupy a much smaller space when compared with lasers,
resulting in less clutter in the operating room. A disadvantage of both radio frequency surgery and lasers is smoke generated
during the procedure. A smoke evacuation system should be considered when using either radio frequency surgery or lasers to
incise tissue. Be careful to avoid using alcohol or other flammable substances when preparing skin for surgery if radiosurgery
will be used.
CONCLUSION
Practicing veterinarians have many alternatives for making incisions during surgery. The choice of instruments varies depending
on the surgeon's preference and experience, tissue to be cut, procedure to be performed, and cost of equipment.
In my practice, I have found that the lack of hemorrhage and the ability to incise tissue without extensive manipulation when
using radio frequency surgery greatly reduces surgery time. Additionally, I have observed that animals have less postoperative
swelling when I use radiosurgery rather than a scalpel, resulting in less self-trauma and less dehiscence.
The learning curve for radiosurgery is not steep for veterinarians familiar with scalpels. Similar tactile movements are required.
The most difficult sensation to learn is that no resistance is felt when incising tissue. In our practice, we are developing
techniques to raise conjunctival flaps, replace hyperplastic third eyelid glands, and perform enucleations in addition to
correcting eyelid abnormalities. Practitioners should consider radiosurgery as an alternative to steel scalpels when performing
surgery on easily deformable and highly vascular tissue.
William W. Miller, DVM, MS, DACVO
Advanced Animal Eye Clinic
3767 Summer Ave.
Memphis, TN 38122
REFERENCES
1. Older, J.J.: The value of radiosurgery in oculoplastics. Ophthalmic Plast. Reconstr. Surg. 18(3):214-218; 2002.
2. Niamtu, J.: 4.0 MHz radio wave applications in cosmetic facial surgery. Cosmetic Derm. 16:33-46; 2003.
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