Lasers versus Female Complaints

Abstract

People who think of lasers in surgery are likely to think first of eye surgery. It was in that department of surgery that lasers were first employed, and in which over the years they have received a good deal of publicity. Gynecology is reputed to be one of the largest medical specialties. Whatever may be the comparative statistics between gynecological surgery and ocular surgery. it is certain that the world's hospitals see a good number of gynecological operations in a year. Thus, the extension of laser techniques to gynecological treatments, which has begun in the last couple of years, promises to add greatly to the number of those who benefit from the laser's surgical capabilities. Among those benefits, according to J. H. Bellina of Louisiana State University School of Medicine, who was invited to review progress in the field at the recent Lasers '80 Conference in New Orleans, is a higher probability of eradication of premalignant and malignant conditions and the maintenance or restoration of fertility in cases where other techniques could not. The instrument generally used for this work, he says, is the so-called AO 100, which uses articulated mirrors to deliver a spot of laser light to the point where the surgeon wants it. This system has gotten smaller over the years since 1974, Bellina says, both in gross physical size -its electrical housing was once six feet across and in the size of the spot of laser light it delivers, which can now be as small as 125 micrometers under certain conditions. One purpose of these tiny pinpoints of light is to destroy the abnormal growths in the lining of the cervix, known as dysplastic cells, and the carcinoma in situ or superficial cancer that sometimes develops from the dysplastic lesions. Dysplasia is not a rare disease. Bellina says it is reaching epidemic proportions in the United States, not to mention other parts of the world. Furthermore, the age of onset has been dropping. Years ago dysplasia was seen usually in mature women, women in their thirties and older. Now the average age of incidence is in the 14to 25-year range, Bellina says, and pushing toward the pre-teen years. The carcinoma that may develop from it is not far behind: Bellina says the earliest carcinoma in situ in his experience was in a 14-year-old. And I've had a 21-year-old already dead from it, he adds. Not all appearances of dysplasia which is sometimes called precancerous tissue develop into malignancies. The figure is about 30 percent. The rest tend to regress and disappear. But we don't have a good model to tell us which will and which won't, says Bellina. So the obvious therapeutic procedure is to get rid of it all, to destroy the dysplastic cells thoroughly enough to prevent recurrences. At the beginning of the 1970s cryosurgery was applied, but there seemed to be a hazard: the survival of a certain amount of the DNA of the dysplastic cells, which could then serve to trigger a recurrence. Lasers were brought in to see if they could do better. One question was how deep the killing of cells and destruction of DNA had to go. The textbooks said 3 millimeters deep. Cryosurgery had gone that deep, but apparently something underneath had escaped. Textbooks to the contrary, Bellina says, Nobody had ever sat down and measured this. The laser surgeons tried at first to develop some range finding indicators, but the effort proved costly, and the patients' heartbeats were confusing the issue because they gave the tissue pulsations with a 2-millimeter amplitude. The researchers decided to do the job clinically, starting very shallow and going deeper and deeper till they reached a point of optimum benefit. At 3 millimeters they had a 16 percent recurrence rate. They decided, Bellina says, We'll go wider and just go deeper. The depth went to 4, 4.5, 5 even to 7 millimeters. Below 5 millimeters they got the recurrence rate down to 4.4 percent. As of today, in 1,500 cases that they have followed for some time, there is a recurrence rate of about 5 percent. Where there is carcinoma in situ, the laser technique is to try to destroy all of the tumor. The way this is done, the way the laser heat transfer vaporizes the cells and destroys the chemical bonds in their DNA and RNA material, seems particularly effective in destroying the malignancy and preventing recurrence. As an example, the 14-year-old girl mentioned above, who caught the disease from her mother, has now been followed for two years without a recurrence.