Doctors Crowd S.D. Symposium : Bright Light Shines on the Latest in Laser’s Medical Magic
The first images on the physician’s instructional videotape are not pleasant: a dirty red-and-white, ball-shaped mass--a tumor--blocking the airway of an elderly man.
But then a flexible tube-like instrument enters the airway, and within a minute the tumor begins to shrink, vaporized by intense heat from the device. The easier breathing of the patient is clearly visible as the lung pulsates with greater regularity.
Such is the “magic” of the medical laser as applied to lung cancer victims whose inoperable tumors would otherwise render their lives unbearable with labored breathing and frequent, bloody coughing. A laser, with its penetrating light source, allows UC San Diego Medical Center doctors to vaporize the cancerous tissue without major risk of uncontrolled bleeding, the major reason why normal surgery cannot be attempted.
The application of the laser to such tumors is one of the latest and more dramatic uses of an instrument that has become common in many medical surgeries, such as removing lesions on vocal chords in children--a common disease--without causing damage to the larynx. In many cases, lasers allow surgeries to be performed more quickly, with less bleeding and fewer post-operation complications compared with standard procedures. And in the case of tumors in airways, there is no other alternative.
Twenty-five years after the laser was invented at a Hughes Aircraft laboratory as an industrial cutting tool, “there has been a veritable explosion of its use in medicine in the 1980s,” according to Dr. Jack Fisher of Boston, a well-known, longtime proponent of laser use in surgeries. Experiments are under way to explore laser use for heart by-pass work and to clear fatty deposits from arteries.
At a San Diego symposium last week to mark consolidation of UCSD hospital’s laser procedures into its new laser center, more than 100 doctors crowded an auditorium to hear about present applications for body areas including the brain, bladder, uterus, throat, eye and skin.
“I certainly was surprised at the numbers (who showed up),” said Dr. Terence Davidson, a UCSD surgeon specializing in head and neck diseases. “Certainly the most important thing is to make physicians within a community aware of the diseases that can be treated well with lasers.”
A laser traditionally connotes Star-Wars wizardry, with blazing lights slashing through interstellar constellations as space stations vie for universal supremacy. But doctors try hard to take the mystery out of their procedures by explaining the concept in laymen’s terms, to reassure patients of the laser’s legitimacy.
The term itself is an acronym for a method of concentrating light through precise frequencies traveling the same direction. In simplified terms, the light is created by stimulating radiation energy from atoms, one after another.
Several different types of lasers exist for medical use, among them the argon laser, the carbon dioxide laser and the yag laser, with the names indicating the different type of gas that generate various light intensities. With human tissue, the laser light is reflected, absorbed or scattered, depending on the power of the laser.
The yag laser is the most powerful and is able to penetrate tissue four millimeters from the point of entry. On the other hand, the carbon dioxide laser, while it penetrates only to one-tenth of a millimeter, can cut a precise line and works very well for small incisions.
Dr. James H. Harrell of UCSD is among the top specialists worldwide in pulmonary use of lasers. Harrell, along with French scientists, has pioneered in cutting down bulky lung tumors that block patients’ airways. UCSD is one of a handful of medical centers nationwide where patients now come for the procedure, which usually requires less than a day.
“We can’t cure the tumors, but by reducing them, we certainly allow the patients to live better through treating them symptomatically,” Harrell said. “These are patients who have failed to improve with standard treatments (surgery and radiation), who have a large cancer blocking their breathing that causes bleeding, cough, infection, pneumonias.”
Because such tumors often grow into or exist near the major arteries of the body, standard surgery is usually impossible because uncontrolled bleeding would fill the lungs and result in death.
“But the yag laser works because it cauterizes and closes the blood vessels as it vaporizes the tumor mass, limiting the bleeding,” Harrell said. “The work is akin to cutting back a weed.”
Harrell said that the operation is more difficult than others involving lasers because the articulated arm and small camera he uses must share the airway without blocking the patient’s ability to breathe during the operation. The surgery takes more dexterity and judgment than normal operations, such as knowing when bleeding--which always occurs to some extent--is abnormal.
“I explain to patients that we have a good surgical team, we never take the procedure lightly, we are always conscious of getting through it without problems, that we have only lost one of 200 patients,” Harrell said.
“I look at them and say, ‘I think I can get you through the operation and if you don’t do the operation, you are going to cough more, feel worse, etc.’ ”
The tumors do grow back after a while, depending on the severity of the cancer, Harrell said. Many patients come back in intervals ranging from three to six months to have the operation performed again. In the interim, they lead much more productive lives because of the ability to breathe more normally, Harrell said.
“They live in two- to three-month blocks,” Harrell said. “But that gives them a chance to look forward to significant events, such as getting through to the next graduation or wedding--and that can be extended indefinitely.” Many are elderly persons exhibiting the inevitable consequences of smoking for much of their lives.
While the first-time patient, along with his or her family, exhibits nervousness, the second or third time around finds the patient treating the operation as routine. Harrell expresses anger that Medi-Cal and Medicare administrators will not pay for the procedure as yet because they still consider it experimental. Harrell counters that the government should examine the UCSD program and set standards or guidelines for individual hospital reimbursements, rather than simply making a blanket nationwide prohibition on payments.
Other laser operations have already become the surgeries of choice.
Lasers allow removal of warts on adolescent larynxes that previous surgical removal using forceps resulted in scarring and an abnormal voice, Dr. Davidson said. Small vocal voice cancers can now be completely removed using lasers, allowing doctors to avoid extensive surgery, which cause much bleeding and weeks of radiation, he said.
Davidson is also experimenting with lasers to operate on sinuses responsible for the sense of smell. Millions of Americans have lost their sense of smell due to either bacterial infection or allergies. Standard operations on these sinuses are extremely difficult, Davidson said.
“Lasers are not a cure-all and are not always the answer,” Davidson said. “You can do an appendectomy, but it would take twice as long and not really prove much better than conventional therapy. Lasers are most useful in areas where bleeding can be a major problem and where relatively delicate procedures are involved.”
