Lecture 23: Basics of Laser Surgery Flashcards
why laser surgery
- Cleaner surgery with less swelling
- Seals small blood vessels, lymphatics and nerves
- Reduced post-op morbidity
- Target specific tissue effects
- Sanitizes wound
- Endoscopic sx
Describe the components of a laser
- Energy source that goes to laser medium
- Bounces off reflective mirror to partial reflective mirror
- Out tube to tissue
What are the 3 components of laster light
- Coherent/parallel
- Monochromatic
- Collimated/stays together
What characterizes a laser
Wavelength
What does wavelength determine
Tissue interaction
What lasers are not absorbed by water, but target dark tissue- melanin, pigment, hemoglobin
- Nd:YAG
- Diode
What laser is absorbed by water and would vaporize the cornea
CO2
Which lasers have deep tissue penetration
- NG:YAG
- Diode
- Ho:YAG (deepest)
Which laser has more superficial penetration but is effective against all tissues because it targets water
CO2 laser
What is power
Rate at which energy is delivered
Power is measured in __
Watts
What is power density
Power delivered/unit area
What is fluence
Amount of energy delivered/unit area
How is power density affected by spot size/nozzle applied
The smaller the nozzle the greater the power density
What is the relationship between power density and watts
The greater the power density the less requirement watts required
Should you use the highest or lowest power possible for a laser
Highest
What lasers could be used intentionally to target the retina
Nd:YAG and diode
What is the purpose of Heliox
Reduce fire hazard
Should you used a pulsed laser or continuous laser and why
Pulse laser, minimizes collateral heating
What contact laser tip should you apply black sharpie on and why
Quartz fibers to focus energy at tip, prevent deeper penetration
Which is a contact quartz fiber vs non-contact quartz fiber
top: contact
Bottom: non-contact
Power density can be adjusted with ___size and distance from ___
Aperture size of tip, tissue
What kind of delivery system is this
articulated arm
What type of delivery system is this and what laser won’t it transmit
Quartz fiber flexible endoscope
Won’t transmit CO2 laser
What laser is best for general surgeries but has limited endoscopic use
CO2 laser
What lasers are better for endoscopic applications
Diode and Nd:YAG lasers
What type of laser has a high power density, moves across tissue so fast that it ablates tissue uniformly and doesn’t cause char
Scanner
How does a scanner not cause char
Tissue not allowed to cool enough
When making a laser incision you must keep __on tissue
Tension
Do you have delayed healing with CO2 laser
Not with adequate power density and efficient movement of handpiece
