In today's world of ever-improving medical technology, cardiovascular disease has become the second killer of human beings after cancer. Therefore, the development of laser medicine, in addition to surgery, eye surgery and tumor treatment, the next target is the human heart and vascular system. As far as the United States is concerned, there are thousands of heart disease patients, and the annual cost of treatment exceeds $10 billion. Therefore, the prospects and market for the application of its laser therapy in the cardiovascular system are extremely broad.
Biochromic gene tracer method
A foreign high-tech company has adopted this more specific technology for the symptoms of atherosclerosis. It involves attaching a unitary antibody to a hardened plaque through a chromogenic tracer to effectively absorb laser energy, and then using an optical fiber to transmit the energy to the plaque along the blood vessel. This allows the plaque to be selectively destroyed without affecting the surrounding artery wall tissue.
Laser/Balloon Combination Method
This technique uses a yttrium-aluminum-garnet laser beam to soften the hardened plaque, and then squeezes the plaque against the vessel wall with the pressure of an expanding balloon. Irradiation is performed three to four times over a 20-second period, with each laser dose being 380 or 450 millijoules. This method reduces the likelihood of re-narrowing the vessel because it smooths the artery wall. One company has also combined a vascular endoscope, CCD camera, and pulsed dye laser into a dye laser angioplasty system. The positioning of its catheter nozzle is controlled by a computer and motorized device. The laser has a wavelength of 480 nanometers and produces 200 millijoules of energy. The treatment begins with the expansion of a balloon to block the blood flow, followed by direct ablation with the laser. Its short pulses ablate sclerotic spots with no effect on the artery walls.
Laser/Catheter Method
This technique uses a laser catheter adapted for use in the human body to transmit a yttrium-aluminum-garnet laser beam, through the laser catheter, to a sapphire laser nozzle on a fiber-optic head. A 2- to 3-millimeter channel is first opened with the laser in the fully blocked sclerotic plaque of the leg artery, and then a balloon catheter is inserted, which expands to press the remaining plaque against the artery wall, thereby unblocking the fully blocked leg artery. The key to employing this technique is reportedly controlling the temperature of the laser catheter nozzle. That's because if the temperature is not right, it can cause coronary artery spasms and thrombosis.
Laser/tissue-recognition combination
In March 1989, at the annual meeting of the American College of Cardiology, more than 20,000 attendees were given a tour of a company's "Dexterity" laser system. This is a novel, high-tech angioplasty procedure. It combines laser technology with tissue-recognition technology and involves highly sophisticated techniques such as spectroscopy, ultrasound, medical dyes, and nuclear magnetic **** vibration.
The treatment selectively attaches the dye to the sclerotic plaque through unitary antibodies, based on the nuclear magnetic **** vibration imaging system, which carries out in vivo bio-analysis of the plaque with a small magnetic coil and relies on spectroscopic analysis of the low-brightness laser beam to obtain the location of the plaque, and utilizes its feedback signals to guide the therapeutic laser beam to the diseased tissue.
The system is a dual laser beam that uses microcomputer-controlled sclerotic plaque detection/targeting as a feedback mechanism to prevent vessel perforation. There are two delivery catheters working, a single soft fiber for the recanalization function of fully blocked arteries, and a multibeam fiber optic catheter for loosening fully blocked or partial blockages.
Myocardial perforation penetration
This method is used in patients with narrow coronary arteries in the doughnut, which results in the inability to loop the coronary arteries. The principle is very simple, with a high-power laser in the myocardium directly perforated through. There is very little information reported because of the limited indications.
It should be noted that the laser has not been successful in eliminating calcifications that are common in atherosclerosis. The Irvine study found that such objects are responsible for accidents in which fiber bundles are deflected and puncture blood vessels.