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. 2023 Jul 10;7(4):zrad051.
doi: 10.1093/bjsopen/zrad051.

Evaluation of intraoperative neuromonitoring (IONM) data with the Mainz IONM Quality Assurance and Analysis tool

Thomas J Musholt  1 , Julia I Staubitz  1 , Petra B Musholt  1
Affiliations

Evaluation of intraoperative neuromonitoring (IONM) data with the Mainz IONM Quality Assurance and Analysis tool

Thomas J Musholt et al. BJS Open. .

Abstract

Background: Intraoperative neuromonitoring is widely used in thyroid and parathyroid surgery to prevent unilateral and especially bilateral recurrent nerve paresis. Reference values for amplitude and latency for the recurrent laryngeal nerve and vagus nerve have been published. However, data quality measures that exclude errors of the underlying intraoperative neuromonitoring (IONM) data (immanent software errors, false data labelling) before statistical analysis have not yet been implemented.

Methods: The authors developed an easy-to-use application (the Mainz IONM Quality Assurance and Analysis tool) using the programming language R. This tool allows visualization, automated and manual correction, and statistical analysis of complete raw data sets (electromyogram signals of all stimulations) from intermittent and continuous neuromonitoring in thyroid and parathyroid surgery. The Mainz IONM Quality Assurance and Analysis tool was used to evaluate IONM data generated and exported from 'C2' and 'C2 Xplore' neuromonitoring devices (inomed Medizintechnik GmbH) after surgery. For the first time, reference values for latency and amplitude were calculated based on 'cleaned' IONM data.

Results: Intraoperative neuromonitoring data files of 1935 patients consecutively operated on from June 2014 to May 2020 were included. Of 1921 readable files, 34 were excluded for missing data labelling. Automated plausibility checks revealed: less than 3 per cent device errors for electromyogram signal detection; 1138 files (approximately 60 per cent) contained potential labelling errors or inconsistencies necessitating manual review; and 915 files (48.5 per cent) were indeed erroneous. Mean(s.d.) reference onset latencies for the left vagus nerve, right vagus nerve, recurrent laryngeal nerve, and external branch of the superior laryngeal nerve were 6.8(1.1), 4.2(0.8), 2.5(1.1), and 2.1(0.5) ms, respectively.

Conclusion: Due to high error frequencies, IONM data should undergo in-depth review and multi-step cleaning processes before analysis to standardize scientific reporting. Device software calculates latencies differently; therefore reference values are device-specific (latency) and/or set-up-specific (amplitude). Novel C2-specific reference values for latency and amplitude deviate considerably from published values.

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Figures

Fig. 1
Fig. 1
Mainz IONM Quality Assurance and Analysis tool graphic output for an exemplary case
Fig. 2
Fig. 2
Flow chart summarizing the process of data evaluation and correction
Fig. 3
Fig. 3
Exemplary machine error
Fig. 4
Fig. 4
Modified electromyograms
Fig. 5
Fig. 5
Comparison of latency data before and after data cleaning
Fig. 6
Fig. 6
Reference values
Fig. 7
Fig. 7
Device-specific reference ranges
See this image and copyright information in PMC

References

    1. Dralle H, Lorenz K, Schabram P, Musholt TJ, Dotzenrath C, Goretzki PEet al. . Intraoperative neuromonitoring in thyroid surgery. Recommendations of the Surgical Working Group for Endocrinology. Chirurg 2013;84:1049–1056 - PubMed
    1. Randolph GW, Dralle H, Abdullah H, Barczynski M, Bellantone R, Brauckhoff Met al. . Electrophysiologic recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery: international standards guideline statement. Laryngoscope 2011;121(Suppl 1):S1–S16 - PubMed
    1. Schneider R, Randolph GW, Dionigi G, Wu CW, Barczynski M, Chiang FYet al. . International Neural Monitoring Study Group guideline 2018 part I: staging bilateral thyroid surgery with monitoring loss of signal. Laryngoscope 2018;128(Suppl 3):S1–S17 - PubMed
    1. Wu CW, Dionigi G, Barczynski M, Chiang FY, Dralle H, Schneider Ret al. . International Neuromonitoring Study Group guidelines 2018: part II: optimal recurrent laryngeal nerve management for invasive thyroid cancer-incorporation of surgical, laryngeal, and neural electrophysiologic data. Laryngoscope 2018;128(Suppl 3):S18–S27 - PubMed
    1. Brauckhoff M, Machens A, Sekulla C, Lorenz K, Dralle H. Latencies shorter than 3.5 ms after vagus nerve stimulation signify a nonrecurrent inferior laryngeal nerve before dissection. Ann Surg 2011;253:1172–1177 - PubMed

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