Laser lithotripsy

Laser lithotripsy
Intervention
ICD-9-CM 98
MeSH D017602

Laser lithotripsy is a surgical procedure to remove stones from urinary tract, i.e., kidney, ureter, bladder, or urethra.

History

Laser lithotripsy was invented at the Wellman Center for Photomedicine at Massachusetts General Hospital in the 1980s to remove impacted urinary stones. Optical fibers carry light pulses that pulverize the stone. Candela licensed the technology and released the first commercial laser lithotripsy system.[1] Initially 504 nm dye lasers were used, then holmium lasers were studied in the 1990s. Several companies currently produce holmium lasers for lithotripsy including Lumenis, DirexGroup, Trimedyne, and Electro Medical Systems.

Procedure

A urologist inserts a scope into the urinary tract to locate the stone. The scope may be a cystoscope, ureteroscope, renoscope or nephroscope. An optical fiber is inserted through the working channel of the scope, and laser light is directly emitted to the stone. The stone is fragmented and the remaining pieces are washed out of the urinary tract.

The procedure is done under either local or general anesthesia and is considered minimally invasive surgery. It is widely available in most hospitals in the world.

Comparison

Laser lithotripsy (LL) has been evalulated against Extracorporeal Shock Wave lithotripsy (ESWL), finding both to be safe and effective.[2][3] ESWL may be safer for small stones (<10 mm), but less effective for 10–20 mm stones.[2] A 2013 meta-analysis found LL can treat larger stones (> 2 cm) with good stone-free and complication rates.[4]

Holmium laser lithotripsy had superior initial success and re-treatment rate compared to Extracorporeal shock wave lithotripsy (ESWL) in a 2013 trial.[5]

Lasers

Pulsed dye lasers with wavelength 200-550 microns[6] have been used for lithotripsy of biliary and urinary stones.[7]

Holmium:YAG lasers have wavelength of 2100 nm (infrared) and are used for medical procedures in urology and other areas. They have qualities of CO2 and Nd:Yag lasers, with ablative and coagulation effects.[8] Holmium laser use results in smaller fragments than 320 or 365 micron pulsed dye lasers or electrohydraulic and mechanical methods.[9]

Thulium lasers are being investigated

References

  1. ↑ "Research Discoveries". Wellman Center for Photomedicine. Retrieved 30 April 2011.
  2. ↑ 2.0 2.1 "A Prospective Randomized Comparison Between Shock Wave Lithotripsy and Flexible Ureterorenoscopy for Lower Caliceal Stones ≤2 cm: A Single-Center Experience.". J Endourol. Nov 18, 2014. doi:10.1089/end.2013.0473. PMID 25203489.
  3. ↑ "Flexible Ureterorenoscopy versus Extracorporeal Shock Wave Lithotripsy for the treatment of upper/middle calyx kidney stones of 10-20 mm: a retrospective analysis of 174 patients.". Springerplus 3: 557. Sep 24, 2014. doi:10.1186/2193-1801-3-557.
  4. ↑ "Flexible ureteroscopy and laser lithotripsy for stones >2 cm: a systematic review and meta-analysis.". J Endourol. 26: 1257–63. Oct 2012. doi:10.1089/end.2012.0217. PMID 22642568.
  5. ↑ "Management of impacted proximal ureteral stone: Extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy.". Urol Ann. 5: 88–92. Apr 2013. doi:10.4103/0974-7796.110004. PMID 23798864.
  6. ↑ "Endoscopic pulsed-dye laser lithotripsy: 159 consecutive cases.". J Endourol. 8: 25–7. Feb 1994. doi:10.1089/end.1994.8.25. PMID 8186779.
  7. ↑ "Pulsed dye laser lithotripsy--currently applied to urologic and biliary calculi.". J Clin Laser Med Surg. 9: 355–9. Oct 1991. PMID 10150133.
  8. ↑ "Laser prostatectomy with the holmium: YAG laser". Tech Urol. 1: 217–21. Winter 1995. PMID 9118394.
  9. ↑ "Holmium:YAG lithotripsy yields smaller fragments than lithoclast, pulsed dye laser or electrohydraulic lithotripsy.". J Urol. 159: 17–23. Jan 1998. doi:10.1016/s0022-5347(01)63998-3. PMID 9400428.

See also