Lecture 23: Basics of Laser Surgery

Question 1

why laser surgery

Answer 1

1. Cleaner surgery with less swelling
2. Seals small blood vessels, lymphatics and nerves
3. Reduced post-op morbidity
4. Target specific tissue effects
5. Sanitizes wound
6. Endoscopic sx

Question 2

Describe the components of a laser

Answer 2

1. Energy source that goes to laser medium
2. Bounces off reflective mirror to partial reflective mirror
3. Out tube to tissue

Question 3

What are the 3 components of laster light

Answer 3

1. Coherent/parallel
2. Monochromatic
3. Collimated/stays together

Question 4

What characterizes a laser

Answer 4

Wavelength

Question 5

What does wavelength determine

Answer 5

Tissue interaction

Question 6

What lasers are not absorbed by water, but target dark tissue- melanin, pigment, hemoglobin

Answer 6

1. Nd:YAG
2. Diode

Question 7

What laser is absorbed by water and would vaporize the cornea

Answer 7

CO2

Question 8

Which lasers have deep tissue penetration

Answer 8

1. NG:YAG
2. Diode
3. Ho:YAG (deepest)

Question 9

Which laser has more superficial penetration but is effective against all tissues because it targets water

Answer 9

CO2 laser

Question 10

What is power

Answer 10

Rate at which energy is delivered

Question 11

Power is measured in __

Answer 11

Watts

Question 12

What is power density

Answer 12

Power delivered/unit area

Question 13

What is fluence

Answer 13

Amount of energy delivered/unit area

Question 14

How is power density affected by spot size/nozzle applied

Answer 14

The smaller the nozzle the greater the power density

Question 15

What is the relationship between power density and watts

Answer 15

The greater the power density the less requirement watts required

Question 16

Should you use the highest or lowest power possible for a laser

Answer 16

Highest

Question 17

What lasers could be used intentionally to target the retina

Answer 17

Nd:YAG and diode

Question 18

What is the purpose of Heliox

Answer 18

Reduce fire hazard

Question 19

Should you used a pulsed laser or continuous laser and why

Answer 19

Pulse laser, minimizes collateral heating

Question 20

What contact laser tip should you apply black sharpie on and why

Answer 20

Quartz fibers to focus energy at tip, prevent deeper penetration

Question 21

Which is a contact quartz fiber vs non-contact quartz fiber

Answer 21

top: contact
Bottom: non-contact

Question 22

Power density can be adjusted with ___size and distance from ___

Answer 22

Aperture size of tip, tissue

Question 23

What kind of delivery system is this

Answer 23

articulated arm

Question 24

What type of delivery system is this and what laser won’t it transmit

Answer 24

Quartz fiber flexible endoscope

Won’t transmit CO2 laser

Question 25

What laser is best for general surgeries but has limited endoscopic use

Answer 25

CO2 laser

Question 26

What lasers are better for endoscopic applications

Answer 26

Diode and Nd:YAG lasers

Question 27

What type of laser has a high power density, moves across tissue so fast that it ablates tissue uniformly and doesn’t cause char

Answer 27

Scanner

Question 28

How does a scanner not cause char

Answer 28

Tissue not allowed to cool enough

Question 29

When making a laser incision you must keep __on tissue

Answer 29

Tension

Question 30

Do you have delayed healing with CO2 laser

Answer 30

Not with adequate power density and efficient movement of handpiece