[The experimental research for electrophysiology detection and electron microscopic observation on the ultrasonically activated shears injures recurrent laryngeal nerve at different time].
OBJECTIVE
To determine the correlative factors on recurrent laryngeal nerve (RLN) injuries caused by ultrasonically activated shears (UAS).


METHODS
Fifteen New Zealand rabbits (thirty recurrent laryngeal nerves) were randomly divided into 5 groups: group 1 and group 2 are those UAS works 1 mm away from RLN for 2 s and 4s separately, group 3 and group 4 are those UAS works 3 mm away from RLN for 2 s and 4 s separately, and the other one is control group. Electrophysiology was detected in each group. The RLN injuries of group 2, 3 and control group were observed with electron microscope.


RESULTS
Significant differences on amplitude and latency were found in all the experimental groups except group 3 when compared to the control group, and between every two experimental groups as well. Histological changes such as obviously swelling myelin lamellar, loosen and disordered structures, bubble-liked axon collapse and liquefaction of axoplasm were only observed in group 2.


CONCLUSIONS
UAS is a new apparatus for cutting and coagulating in operations, which is safe and reliable to be applied for endoscopic surgery. It will be a new choice for treating thyroid neoplasm.
Department of Otolaryngology-Head and Neck Surgery, Renji Hospital, Shanghai Jiaotong University, Shanghai 200001, China.
Zheng
Z
Zhou
Jiadong
J
Wang
Xin
X
Li
D000818:Animals; D004195:Disease Models, Animal; D055724:Electrophysiological Phenomena; D011817:Rabbits; D061226:Recurrent Laryngeal Nerve Injuries; D013525:Surgical Instruments / Q000009:adverse effects; D014464:Ultrasonic Therapy / Q000009:adverse effects* / Q000295:instrumentation*