Laser resistance of expandable metal stents in interventional bronchoscopy: an experimental evaluation.
OBJECTIVE
Nd-YAG non-contact laser therapy is used to eliminate recurrent tumor tissue within airway stents. This study was performed to determine maximum exposure time until the stent wire is destroyed as well as exposure time necessary to deliberately fracture the wire mesh.


METHODS
Strecker stents, Wallstents, and Nitinol Accuflex stents were implanted into pig bronchi. Then Nd-YAG laser light was directed to the stent wires at different power levels. Portions of the stent surrounded by bronchial tissue as well as bare wires were investigated.


RESULTS
The Strecker stent and the Wallstent revealed a considerably higher laser resistance than did the Nitinol Accuflex stent. At 15 W, minimum exposure time until wire destruction was 4.6 and 6.3 s for the Strecker stent and the Wallstent respectively. In contrast, the Nitinol Accuflex stent tolerated only 1.7 s.


CONCLUSIONS
Laser therapy with bronchial wire stents can be carried out at low power levels. It should, however, be avoided in the case of Nitinol Accuflex stents due to their low heat tolerance.
Hautmann
H
H
Division of Pneumology, Medizinische Klinik, Klinikum Innenstadt, Ludwig-Maximilians-University, D-80336 Munich, Germany. hautmann@medinn.med.uni-muenchen.de
Huber
R M
RM
D000497:Alloys; D000818:Animals; D001980:Bronchi / Q000601:surgery; D001999:Bronchoscopy; D002858:Chromium Alloys; D053685:Laser Therapy; D007834:Lasers; D008175:Lung Neoplasms / Q000601:surgery; D015607:Stents; D013552:Swine; D013635:Tantalum
D000497:Alloys; D002858:Chromium Alloys; C013616:nitinol; D013635:Tantalum