Computer-assisted evoked electromyography with stimulating surgical instruments for recurrent/external laryngeal nerve identification and preservation in thyroid and parathyroid operation

Alan P B Dackiw, Lorne E. Rotstein, Orlo H. Clark, William B. Inabnet, Ashok R. Shaha, Edwin Kaplan, Henning Dralle, Clive S. Grant

Research output: Contribution to journalArticle

43 Scopus citations


Background. The reported incidence of recurrent laryngeal nerve (RLN) palsy/paralysis in thyroid and parathyroid operation ranges from 2% to 13%. Injury to the external branch of the superior laryngeal nerve (EBSLN) is less clearly documented. We hypothesized that a novel evoked electromyography system using an audio warning alarm might be beneficial for detection and preservation of the RLN and EBSLN. Methods. A total of 117 thyroid/parathyroid operations were performed using a nerve locator/monitor (Neurovision SE, RLN Systems Inc, Jefferson City, Mo). Dissection was performed using a stimulating hemostat with conduction to an endotracheal surface electrode. Results. A total of 97 thyroidectomies (50 total, 47 lobectomies) and 20 parathyroidectomies (16 directed, 4 bilateral) were performed representing 176 RLN and 152 EBSLN at risk. Of 176 RLN, 161 were correctly identified by the nerve stimulator alarm including 2 nonrecurrent nerves. The cricothyroid space and the superior pole vessels were scanned to identify the EBSLN by observing for cricothyroideus contraction or an alarm. Fourteen of 152 (8.9%) cases of type 2 anatomy were suggested where meticulous dissection of superior pole vessels prevented EBSLN injury. Conclusions. Computer-assisted evoked electromyography with stimulating surgical instruments is a useful surgical tool. This technology may be especially useful in reoperation in dense scar tissue and preserving the EBSLN in thyroid operation.

Original languageEnglish (US)
Pages (from-to)1100-1108
Number of pages9
Issue number6
StatePublished - Dec 1 2002


ASJC Scopus subject areas

  • Surgery

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