Complications in Equine Surgery. Группа авторов. Читать онлайн. Newlib. NEWLIB.NET

Автор: Группа авторов
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Биология
Год издания: 0
isbn: 9781119190158
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100 W Gas cooled Conical sapphire tip Gas cooled fiber excellent for noncontact ablation CO2 Laser Articulated Arm Delivery 125‐mm focusing handpiece. Minimum spot size 0.16 mm Minimum 30 W Computerized pattern scanner very useful for partial thickness ablation of skin tumors or corneal tumors 30–50 W pulsed mode. Better hemostasis in continuous mode if wound is to be left open Sterilize handpiece and use sterile sleeve for aseptic procedures CO2 Laser Waveguide Delivery 0.25–4.0mm (spot size) tips 15–40W Super pulse available No lens focus of laser beam. Power density varied with distance, power setting or changing diameter of tip Laser Smoke Evacuator Many brands available Spare filters. Performance drops off quickly when filter fills. Sterilize hose for aseptic procedures

      Carbon Dioxide Laser

Photo depicts pulsed laser energy compared to continuous laser energy. Pulsing higher power densities for short durations (vertical bars) produces a more efficient tissue effect with less collateral tissue heating compared to a continuous beam (horizontal bar) emitting the same average power (fluence). The tissue cools slightly between the pulses.

      Carbon dioxide lasers transmit the energy by reflection through mirrors in an articulating arm to a lens in the handpiece to focus the beam (Figure 12.9a). Some models deliver the laser beam through a highly polished flexible waveguide with a hand piece. Interchangeable tips instead of a lens determine spot size (Figure 12.9b). Carbon dioxide lasers are often equipped with pulsed modes (described above), making incisional surgery similar to that of a steel scalpel possible.

      Some CO2 lasers can be fitted with semiflexible waveguides to access deeper surgical sites. Waveguides are actually tubes and are not as flexible as quartz fibers. Some waveguides can be passed through the biopsy channel of some endoscopes, but they are fragile. Excessive bending will reduce the laser energy or damage the waveguide leading to a burn out; these should be kept relatively straight [2].

Photo depicts a) Typical higher-powered CO2 laser delivered through an articulated arm with a lens focusing handpiece. (b) Typical CO2 laser delivered through a flexible waveguide and handpiece with variable aperture tips.

      Source: Courtesy of Aesculite, LLC, Woodinville, WA 98072.

      Equine general surgery holds many applications for the clean, efficient and safe CO2 laser [20–22]. Proper CO2 laser surgery produces much less thermal injury than electrosurgery [23], and tissue generally swells less than conventional surgery. Surgical dead space tends to fill less with serum after laser dissection than with conventional surgical dissection [24]. However, surgical principles for closing dead space remain indicated [2, 9].

      Neodymium Yttrium Aluminum Garnet (Nd:YAG) and Gallium Aluminum Arsenide (GAA) Diode Lasers

      The 1,064‐nm Nd:YAG and 980‐mn GAA diode laser wavelengths behave almost identically in tissue, so the following discussion applies to both. Many Nd:YAG lasers have been replaced by the less expensive and more compact diode units. Nd:YAG lasers are generally sold with outputs up to 100 W, while diode lasers are most often in the 15–50 W range. Higher power output