Dr Ankit Goel
VMMC & SJH, New Delhi
Use of LASER has become the backbone of Urology in the current era of minimal invasion
Holmium:YAG
Properties
2140nm
Depth of penetration: 400 μm
Pulse duration: 500 μsec
Pulse energy: 0.2 - 6J
Energy source: Flash lamp
200μm, 350μm, 550μm fiber
Clinical implications
Longest & most robust safety & efficacy data
MOSES pulse modulation reduces fragmentation time & complications
Steam bubble generated with each laser pulse
High depth of penetration
Retropulsion effect
Bulky machine with special power source
Common Settings
URS fragmentation: 0.6J, 6Hz
URS dusting: 0.6J, 10-20Hz
RIRS popcorning: 1-1.5J, 15-40Hz
RIRS dusting: 0.2-0.8J, 10-70Hz
HoLEP:2J, 40Hz
Thulium Fiber laser
Properties
1940nm
Depth of penetration: 250 μm
Continuous wave output
Energy source: high power laser diodes
50-200μm flexible fiber
Clinical implications
Small & light weight
Less retropulsion
Superior dusting, lower operative time
High water vapour absorption coefficient - better ablation
Greater heat generation
Greater back burn, thinner fibers
Common Settings
URS: 0.1-0.2J, 10-15Hz
RIRS frag: 0.5 -1.5J, 5-60Hz
RIRS dusting: 0.1-0.5J, 20-100Hz
ThuFLEP: 1J, 30-40Hz
Green light laser (LBO)
Properties
532nm
Depth of penetration:1mm
Continuous wave output
Absorbed by hemoglobin
50-200μm flexible fiber
Clinical implications
Superior hemostasis
Beneficial in patients on anticoagulation
Ablation time of 180W - 0.67min/g as compared to 1min/g for 120W
Moxy fibers - saline cooled & automatic cutoff - longer lasting
Common Settings
Ablation: start at 120W, increase to 180W
Coagulation: 80-120W
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