[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).

METHOD: 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.

RESULT: 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.

CONCLUSION

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.