Laser / URS

Question 1

pulse width

Answer 1

Short pulse width mode is approx. 300us
Long pulse mode distributed over 600us or higher
Long pulse mode useful in dusting technique and results in smaller residual fragment size
Long pulse mode decreased retropulsion

Question 2

dusting stone

Answer 2

Low energy 0.5J

High frequency 15-20Hz and long pulse 800us with total power 7.5 w to 10 W is required

Question 3

fragmentation

Answer 3

High energy 1.5 J to 2J
Low frequency 5Hz
Short pulse 200us
Total power 7.5 W to 10 W
Break large stone into small pieces

Question 4

popcorn effect

Answer 4

High energy 1 to 1.5 J
High frequency 10-15Hz
Long pulse 600us
Total power 10-17.5Watts

Question 5

BAUS complications URS - 11

Answer 5

almost all
dysuria
need temporary stent

50%
recurrence stone need treatment

5-15% residual stone, more if closer to kidney

5% failed access
2-10% catheter
1-2% infection

1% minor damage wall
<0.1% major damage
0.25-1% stricture
anaesthetic risk