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Fragmentation of uric acid calculi with the holmium: YAG laser produces cyanide
Author(s) -
Zagone Robin L.,
Waldmann Todd M.,
Conlin Michael J.
Publication year - 2002
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.10094
Subject(s) - cyanide , uric acid , holmium , lithotripsy , laser lithotripsy , chemistry , laser , nuclear chemistry , surgery , medicine , inorganic chemistry , biochemistry , optics , physics
Background and Objectives To independently test previously reported findings of cyanide evolution under holmium:yttrium aluminum garnet (Ho:YAG) (holmium) lithotripsy of uric acid calculi, determine if this occurs with other forms of intracorporeal lithotripsy, and establish if this occurs due to a photothermal, photochemical, or photoacoustic reaction. Study Design/Materials and Methods Human uric acid calculi were fragmented in vitro through exposure to holmium, ultrasound, and electrohydraulic (EHL) energy sources. The following parameters were varied: total laser energy, individual laser pulse energy, ultrasonic energies, and EHL energies. Uric acid powder was suspended in solution and exposed to holmium laser energy in vitro. Serum and irrigant samples from a human patient were collected following intrarenal holmium lithotripsy of a uric acid calculus. All samples were analyzed for hydrogen cyanide (HCN) content. Results Holmium lithotripsy of solid uric acid calculi produces cyanide. The yield is linearly dependent upon total laser energy delivered. Pulse energy does not affect cyanide yield. Photothermal mechanisms coupling laser energy to the solid crystal lattice are responsible for the production of cyanide. Ultrasound and EHL lithotripsy do not produce cyanide. A clinically insignificant level of cyanide was detected in the blood of a single patient following laser lithotripsy of a uric acid calculus. Conclusions Our study confirms that cyanide is produced by a photothermal mechanism during holmium laser lithotripsy of uric acid calculi, and that the amount produced is clinically insignificant. Lasers Surg. Med. 31:230–232, 2002. © 2002 Wiley‐Liss, Inc.