When singers are confronted with the need for surgery, one of the questions they ask most frequently is, “Do you use the laser?” Many people find something comforting about the laser (versus the use of conventional instruments): healing by light, the implicit gentleness and absence of trauma, not to speak of the futuristic, Star Wars cachet of simply aiming a beam of light at a lesion and making it disappear. The newest technology also attracts physicians, and the combination of these two factors seems to make the laser the implicit choice.
Laser surgery undoubtedly, offers a unique and superior method of dealing with some laryngeal problems. The operative word, however, is “some.” Laser ablation of some lesions is advantageous, but for other conditions, laser is the wrong way to treat—conventional microsurgery is the way to go. In the next few paragraphs, I will outline the advantages and disadvantages of lasers for laryngeal surgery.
A laser beam is simply a beam of electromagnetic radiation emitted by an element, which may be in the form of a crystal or a gas. An electrical impulse excites the element, which emits a ray of energy that may or may not be visible, depending on the wavelength. Since all the waves come from the same element, the beam is highly coherent. Most light beams contain a wide spectrum of wavelengths and spread widely, but the laser beam wavelength remains highly focused. This is why laser beams can travel great distances with very little scatter. This coherence also makes the beam powerful.
When the laser beam’s energy is transferred to another medium, such as tissue, it can cause heating, coagulation, or vaporization of the tissue, depending on the power setting. By focusing the beam width and controlling the power and duration of the pulse, a surgeon can determine how much tissue he wants to treat, and what he wants the effect to be. In the larynx, surgeons can use lasers to coagulate blood vessels, cut through tissue (like a scalpel), or vaporize tissues completely. Other kinds of lasers can cut through bone. Industrial lasers can even cut through metal.
I mentioned that the “light beam” of a laser can be visible or invisible, depending on its wavelength. The carbon dioxide laser, one of the older lasers but one still frequently used in otolaryngology, emits an invisible beam, whereas the argon laser emits a greenish beam. Because of the color spectrum, some lasers have a greater affinity for certain colored tissues, usually tissues whose color is complementary to that of the laser beam. For example, the argon laser, greenish in color, is absorbed preferentially by reddish blood vessels, whereas the CO2 laser shows no such affinity.
The final general point about lasers has to do with collateral effects. Lasers heat tissue, and the amount of heat determines a laser’s effect on a lesion. If adjacent, normal tissue is heated, unintended damage may occur. That means the amount of heat this adjacent tissue can absorb without damage is important. Obviously, the ideal laser is one that can focus all of its energy on the intended area with minimal harmful heating of surrounding normal structures.
For laryngeal surgery, the laser can offer several unique benefits. Colored lasers can be adjusted to show a high affinity for blood vessels. These “angiolytic” lasers can coagulate and even vaporize abnormal blood vessels on the vocal folds without damaging underlying structures. So, if the problem of recurrent vocal fold hemorrhage is traced to a leaky or abnormal blood vessel, laser treatment is appropriate. Similarly, lasers may be useful for superficial polyps, especially if there is a vascular component.
In the relatively rare (among singers) situation where a papilloma (wart) or precancerous lesion needs to be vaporized, the laser is again useful. Keep in mind, however, that all of these conditions can also be treated by conventional microsurgery, and, while there are theoretical advantages to the laser, in practice patients usually do well with either approach.
On the other hand, in situations where the lesion is under the surface of the vocal fold, the laser is not ideal. A cyst of the vocal fold may require microdissection and ideally, complete removal. Microscopic instruments are the appropriate way to go here. Similarly, it is more appropriate for surgeons to excise a furrow (sulcus vocalis) with instruments. Surgeons can use some lasers now in development to make microscopic incisions for such procedures, but the advantages of using a laser for such lesions is not at all clear.
A relatively recent advance in lasers is the ability to send the beam through a flexible fiber. This means that some conditions can be treated through a flexible endoscope in the office, with the patient awake (although with local anesthesia). Not needing to be put to sleep for surgery is obviously an advantage and office laser surgery is an exciting new direction for laryngologists. The caveat here is simply that office surgery (with the patient awake, the vocal folds moving with every breath) might not offer the degree of fine control that microsurgery under anesthesia does. So, while this might be recommended for some patients and some lesions, it does not (in its current state) replace conventional laryngeal microsurgery.
So, laser or not? Laser offers significant advantages for some lesions and some patients, but it does not (at its current technological level) replace accurate microdissection for every laryngeal lesion. Your surgeon should have at his disposal both modalities, and use them according to which one might give you the best functional outcome.
DISCLAIMER: The suggestions Dr. Jahn provides in these columns are for general information only, and not to be construed as specific medical advice or advocating specific treatment, which you should obtain only following a visit and consultation with your own physician.
