In vivo results for interstitial laser application in thyroid gland.
OBJECTIVE
Aim of this study was to evaluate the potential of denaturation of hormone active tissue in the thyroid gland by laser induced interstitial thermotherapy (LITT) as a treatment of autonomous hyperthyroidism.


METHODS
An interstitial thyroid laser application (Nd:YAG 1064 nm, 5W, 2 min) was performed in 5 pigs. During laser application, the laryngeal recurrent nerve was controlled electro-physiologically. Postoperatively, TSH, total T(3) (TT(3)) and free T(4) (FT(4)) were measured regularly. After a follow-up period of up to 6 weeks, pigs were sacrificed and the thyroid glands were evaluated histological.


RESULTS
A malfunction of the nerve due to laser treatment was not detected. During the first postoperative week there was a decrease of both FT(4) and TSH whereas TT(3) showed an extreme decline of its plasma levels reaching nearly the detection limit. All values showed a recovery to their initial levels during an interval of 10 days and than increased to levels sometimes higher than baseline. The coagulation zones were demarcated clearly towards normal tissue with increasing fibrosis of the treated areas.


CONCLUSIONS
Interstitial thyroid ablation using a Nd:YAG laser is a minimal invasive, safe and effective procedure. Further evaluation including long term follow-up in humans is needed to confirm these results.
Orth
Klaus
K
Department of General Surgery, Klinikum Emden, Bolardusstr 20, Emden, Germany. k.orth@klinikum-emden.de
Boelke
E
E
Steinbach
G
G
Steiner
R
R
Russ
D
D
D000818:Animals; D004594:Electrophysiology; D017075:Laser Coagulation / Q000379:methods*; D053783:Magnetic Resonance Imaging, Interventional; D019060:Minimally Invasive Surgical Procedures; D012009:Recurrent Laryngeal Nerve / Q000502:physiology; D013552:Swine; D013961:Thyroid Gland / Q000473:pathology / Q000601:surgery*; D013972:Thyrotropin / Q000378:metabolism
D013972:Thyrotropin