Keano,
PLLD is not always safe unfortunately.
Salvage operation for persistent low back pain and... [Photomed Laser Surg. 2006] - PubMed result
It appears to compare well against microD and better for patient due to minimal invasive and outpatient procedure, and less risk of complications.
Comparison of results of 500 microdiscectomies and... [Photomed Laser Surg. 2006] - PubMed result
Don't know why it is not used more often. Maybe surgeon training, or open surgery is more profitable.