Purpose: Foreign bodies of the urinary tract represent a urologic emergency. First-line treatment is endoscopic removal, but this is often impeded by restricted space, especially in the urethra. We postulated that foreign objects could be fragmented by Holmium:YAG laser and investigated its effect on objects of varying composition.
Methods: In a specially designed stage flushed with physiologic saline, medical and non-medical objects of differing composition and diameter were subjected to fragmentation by Holmium:YAG at powers of 18 and 30 W. In additional thermal experiments, 5,000 J was applied to differing volumes of 0.9% sodium chloride. Experiments were repeated ten times.
Results: With one exception (16 Ch silicon catheter) all medical objects were fragmented (latex urinary catheter, ureteral stents, and guidewires). Of non-medical objects (wood, steel, copper, graphite, and nylon) only copper wire was not amenable to laser dissection. These in vitro results were applied in two patients who presented with a pencil (wood and graphite) in the urethra or bladder. After Holmium:YAG laser fragmentation, the pencil could be removed by forceps each.
Conclusion: Foreign objects in the urinary tract can be fragmented with a Holmium:YAG laser. When foreign bodies are too big for initial endoscopic extraction, the clinician should consider this technique as a reasonable and atraumatic option to avoid open surgery.