A laser scalpel is a kind of scalpel used in some types of surgery. It uses energy that produces laser light to cut a living tissue. There are different types of lasers used for different purposes. Common types of laser scalpels include those using high pressure water, carbon dioxide, ultraviolet light, and free electrons.
In soft tissue surgery, a laser scalpel that trusts are often used on the water. Operations that this type of laser would require scalpels, among others, repair of blood vessels, and areas that are required of small incisions. The beam can be adjusted appropriately for various purposes. A focused beam is used for small incisions and a concentrated intensity. Defocusing the beam reduces the intensity and can be used to prevent bleeding vessels.
A carbon dioxide gas laser scalpel. These lasers have a powerful continuous wave. It produces infrared light for the laser beam. Carbon dioxide laser scalpels can be used in cosmetic procedures such as dermabrasion and resurfacing. They can also be used in surgical procedures as elimination of tissue abnormalities, such as polyps, or a skin label require removal.
An ultraviolet laser scalpel, also known as an excimer laser, another type of laser used in medical procedures. The excimer laser is generally used in optical procedures. It is used to alter or correct vision by reshaping the cornea. These procedures are often chosen by people who want to avoid glasses or contact lenses and permanently change vision imperfections.
Similar to an excimer laser, a free electron scalpel laser used for surgery. It can also be used in other soft tissue surgery including those that brain tissue and skin. A free electron beam scalpel produces electrons that are relativistic. This means that the electrons move at a speed of about the speed of light. The jet moves through a magnetic field.
The laser scalpel was invented in 1964. In soft tissue laser surgery, a laser beam ablates or vaporizes the soft tissue with high water content. Diode, Nd: and Er:YAG, and CO2 lasers are used most commonly in soft tissue surgery.CO2 lasers are best for cutting soft tissue because their wavelength is most absorbed by water. The focused CO2 laser beam vaporizes tissue precisely, with little thermal damage to surrounding tissues (thermal coagulation zone is as little as 50 microns). The surgical outcome is thus safe and predictable. The CO2 laser is used in virtually all soft tissue procedures, including face lifts, tumor excision, and surgeries in the oral cavity. CO2 laser surgery is praised for minimized bleeding, less swelling and discomfort, reduced infection risk, and less procedure time, as compared to traditional scalpel surgery. Applications include oral surgery, periodontal surgery, oncological surgery, among many others. In ophthalmology, excimer lasers are used for changing the shape of the cornea, procedures known as LASIK and LASEK.Other surgical fields where the use of a laser scalpel is common are circumcision, neurosurgery and vascular surgery.For research use in cell biology, special laser micro-scalpels can make cuts smaller than a single cell.Laser lancets, e.g. Lasette or LaserDoc, are used as a less painful alternative for drawing small amounts (up to 100 µl) of capillary blood, e.g. for diabetic glucose tests. An adjustable-power flashlamp or diode pumped pulsed Er:YAG laser is typically used. A 150 mJ pulse (focused to 6 J/mm2) can vaporize a 0.025 mm2 of skin to 0.5 mm depth. Today diode lasers, Nd:YAG and Er:YAG (and their variants, differing by pumping methods and host crystal type, e.g. Er,Cr:YSGG laser), and CO2 lasers are most commonly used, but possible benefits of using the vastly more expensive free electron lasers are being researched.
Laser technology has proved to be an invaluable surgical tool, be it to improve eyesight, repair torn retinas, zap kidney stones, or to delicately remove spinal tumors. Still, despite more than four decades of use in the operating room, laser surgery has been limited by the fact that its energy travels in straight lines. This means that a laser works best on areas that can be reached with a straight shot. Maneuvering the beam so that it can reach out-of-the-way areas—without damaging healthy tissue—is sometimes done, using a series of mirrors to guide the laser beam, but this typically dilutes the laser's strength.
An approach to laser surgery on the market for barely more than a year, however, seeks to add a new level of flexibility to optical scalpels by directing the infrared energy of a high-intensity carbon dioxide (CO2) laser through a flexible fiber tube lined with reflective material. This gives the surgeon the ability to snake the laser safely through the body to wherever it is needed without losing any of the beam's strength.
The BeamPath CO2 laser energy system (manufactured by OmniGuide, an optics company in Cambridge, Mass.) marks a significant improvement over optical scalpels used over the past three decades to perform precision microsurgery, says Yair Schindel, OmniGuide's vice president of clinical affairs and business development.
"Going deeper into the body, to places where you couldn't see, was impossible" with the old lasers, delivered through a large articulating arm, he says. "If you couldn't see it, you couldn't get to it."
OmniGuide chose the CO2 laser—produced by exciting carbon dioxide gas within a sealed tube—because it was already commonly used in operating rooms, given its ability to effectively ablate, cut and cauterize tissue. It is the most precise optical scalpel available, Schindel says, adding, other laser-light wavelengths, such as those created using argon or krypton lasers, are not absorbed as quickly by certain human tissues, "so they do more cooking than cutting."
Still, conventional CO2 lasers have difficulty with incisions that must be made at awkward angles. "If you think of a large tumor in the throat, you would have to shoot the laser from [16 inches (40 centimeters)] away, manipulating both the light and the patient to reach the tumor," Schindel says. The alternative: a laryngectomy, a less precise procedure in which all or some the vocal cords are removed. OmniGuide's laser can also be used with a flexible fiber–tipped endoscope. "The surgeon can go through the nose, mouth, ear or other small openings," Schindel says, "and [laser] and view at the same time."
Inside each BeamPath fiber, fewer than 20 microscopic layers of alternating, custom-designed infrared glass and polymer form a reflective system known as a "photonic band-gap structure." (pdf) The design stemmed from research conducted by OmniGuide co-founder and CEO Yoel Fink in 1998 when he was a graduate student at the Massachusetts Institute of Technology's (M.I.T.) Plasma Science and Fusion Center. Fink and his colleagues studied ways to devise the "perfect mirror," a surface that reflects light of all wavelengths and from all angles, for the Defense Advanced Research Projects Agency (DARPA), the U.S. Defense Department's the research arm. Since its 2000 start up, OmniGuide has invested $70 million into researching and developing the materials and technology needed to produce this superthin silicon fiber.
Water, which constitutes more than 60 percent of human tissue, absorbs CO2 laser energy well, enabling such devices to make a more precise cut than a normal scalpel with minimal thermal damage to surrounding healthy tissue, says Lee Nelson, a neurosurgeon with Boulder Neurosurgical Associates in Colorado. BeamPath technology allows CO2 laser energy to be transmitted down a hollow-core fiber and used as a handheld laser scalpel, which Nelson says he used in 30 brain and spinal cord surgeries that he has performed since October. "We knew about the advantages of the CO2 laser," he says, "but it had never been practical to use."
The BeamPath allows surgeons to do some procedures that a normal scalpel cannot do. For example, when a surgeon presses a regular metal scalpel into an organ, it depresses the tissue around it, potentially causing damage to healthy cells surrounding targeted tumors. Unlike a normal scalpel, the BeamPath fiber does not require tissue manipulation, Nelson says, adding, it also controls bleeding better than a metal scalpel by cauterizing, or searing and sealing, nearby blood vessels.
The flexible CO2 laser scalpel has special appeal for lower-back surgery, an area where diseased tissue is often difficult to remove. "When you remove this tissue with standard tools, you are sometimes left with arthritic tissue in the spinal canal causing patients to continue to feel pain even after the surgery," Nelson says. "With the CO2 laser, you can dissolve that [damaged] tissue. Instead of pulling or tearing that tissue, we're now simply ablating it." Nelson says that so far, the patients he has treated this way have experienced less pain than those who have undergone traditional surgery, but he adds that he needs a few more years to expand his sample size enough to prove that the laser is the reason for the reduction in pain.
The cost of the technology—from $500 to $1,800 a fiber—has been the major reason it is not used more widely yet. Nelson says he needs to prove that the BeamPath improves patient outcomes to justify opening his wallet for more of these devices. There are two potential limitations on the fibers: their stability when energized and their inability to be sterilized, which means they must be discarded after each use, Nelson notes.
The fiber used to channel the laser typically lasts four hours, tops, before the laser burns through it and it needs to be replaced, says Bruce Haughey, director of head and neck surgical otolaryngology at Barnes–Jewish Hospital in Saint Louis. He notes that the scalpel's fibers can be replaced in a matter of minutes, however, it also takes longer to make incisions using the BeamPath than it does using straight, line of sight CO2 lasers, because the new technology delivers only about 20 watts, half the cutting power that surgeons wield with the older variety.
Haughey, who has performed about 100 surgeries since 2007 with the BeamPath, says he uses the device to remove tumors—to do minimally invasive microsurgery on patients who would otherwise have had to go under the knife to have malignancies removed from hard-to-reach spots, such as the base of the tongue, the mouth floor, or the side walls of the pharynx (the part of the neck and throat directly behind the mouth and nasal cavity). Haughey says that the flexible BeamPath fiber extends the reach of the laser scalpel in close quarters, easily and safely negotiating healthy tissue to reach targeted growths. To do that in the past, "we could rather crudely bounce the laser off a mirror, but (the beam) lost a lot of power that way," he says, adding that he did that only once or twice out of the thousands of surgeries he has performed.
BeamPath is now primarily used by orthopedic as well as ear, nose and throat surgeons, but Schindel says that gynecologists, pulmonologists and urologists are also interested in seeing if this technology can make the cut.
( By Larry Greenemeier on March 4, 2009)
The conventional surgical method for cutting vascularized tissue with scalpel and scissors may now be improved by use of the laser scalpel. In particular, the frequent interruption necessitated and the poor visibility caused by bleeding may be mitigated owing to the haemostatic properties of laser light. This instrument may be of particular value for tasks involving extrabulbar structures, such as extraocular muscles and lacrimal tissue, as well as for facial surgery.
The mode of action and physical properties of a new laser scalpel are described and its characteristics compared with those of other instruments on the market. The probe consists of a clad, sculptured silica fibre with a core diameter of 0.6 mm and a conical 0.15 mm-diameter cutting tip. Radiation generated by a low cw-Nd:YAG laser module is fed into the probe, at the exit point of which a maximal power density of 57 kW/cm2 is attained. Radiated laser energy penetrates the tissue as an incision is made, thereby inducing an efficient blood flow stasis which is amplified by thermal energy diffusing from the immediate surroundings of the scalpel tip.
In this report, the laser scalpel is implemented for the excision of a vascularized, amelanotic, facial naevus. Both the cutting and haemostatic effects were found to be excellent, occurrence of the latter phenomenon being supported by ultrastructural findings. The healing response was comparable to that observed after conventional surgery.
The new laser scalpel represents an inexpensive and effective cutting and haemostatic tool powered by a standard cw Nd:YAG laser module, with a wide spectrum of potential applications.
( Universität Bern. )
To compare the cutaneous wound healing using the diamond laser scalpel with wound healing using a steel scalpel and electrocoagulation for hemostasis.
A prospective and randomized, comparative trial was conducted on eighteen patients. Fusiform excisions were performed using the diamond laser scalpel on one half of each excision and a steel scalpel with electrocoagulation for hemostasis on the other half. The Clinicon SureBlade diamond laser scalpel was used with the Luxar CO(2) attachment at the 6-8-W settings. Blinded assessment of adverse events and photographs were taken at 1 day, 7-10 days, 4 weeks, and 8-12 weeks. The final scar was evaluated at 8-12 weeks for cosmetic outcome and three physicians blinded to the method of excision evaluated photographs of the wounds. Histologic evaluation was performed on all excisions for collateral thermal damage.
Investigator assessment showed no statistically significant differences between the diamond laser scalpel side and the steel scalpel side with respect to bleeding, bruising, swelling, pain, dehiscence, or final scar appearance. The mean residual thermal damage was 350.3 microm (95% CI +/- 37 microm, P < 0.001). The diamond laser scalpel scored higher on intra-operative coagulation (P = 0.20) although these differences were not statistically significant.
The cosmetic outcomes of cutaneous excisions performed with the diamond laser scalpel are equivalent to excisions performed with steel scalpels with electrocoagulation for hemostasis.
( Department of Dermatology, Naval Medical Center San Diego, San Diego, CA, USA. )