Approach to Signal Loss in Intraoperative Nerve Monitoring in Thyroid Surgery Questionnaire: A Turkish Surgical Perspective

Yalin Iscan ¹ Irem Karatas ^2* Nurcihan Aygun ³ Ahmet Cem Dural ¹ Serkan Teksoz ⁴ Ozer Makay ⁵ Ali Uğur Emre ⁶ Fatih Tunca ⁷ Mehmet Uludag ⁸ GÖKHAN İÇÖZ ⁷ Yasemin Giles Senyürek ⁷ Adnan Işgör ⁹ Mehmet Haciyanli ¹⁰

• ¹ Department of General Surgery, Faculty of Medicine, Istanbul University, Istanbul, Türkiye
• ² Department of General Surgery, Mardin Training and Research Hospital, Mardin-Türkiye, Türkiye
• ³ Department of General Surgery, Şişli Hamidiye Etfal Education and Research Hospital, Istanbul, Türkiye
• ⁴ Division of Endocrine Surgery, Department of General Surgery, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul-Türkiye, Türkiye
• ⁵ Department of General Surgery, Ozel Saglik Hospital, Izmir, Türkiye
• ⁶ Departmant of General Surgery, Anadolu Medical Center Hospital, Istanbul-Türkiye, Türkiye
• ⁷ Division of Endocrine Surgery, Department of General Surgery, Istanbul University, Istanbul Faculty of Medicine, Istanbul-Türkiye, Türkiye
• ⁸ Division of Endocrine Surgery, Department of General Surgery, University of Health Sciences, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul-Türkiye, Türkiye
• ⁹ Department of General Surgery, Sisli Memorial Hospital, Istanbul-Türkiye, Türkiye
• ¹⁰ Departmant of General Surgery, Izmir Katip Celebi University, Atatürk Training And Research Hospital, Izmir-Türkiye, Türkiye

Purpose: This study aimed to evaluate surgeons' use of intraoperative nerve monitoring (IONM) during thyroidectomy and their approach to loss of signal (LOS) in various clinical scenarios.A survey was conducted by the Turkish Endocrine Surgery Society on members of the Society in February 2020 and consisted of 16 questions. The practice of IONM use, rate of inclusion in informed consent texts, and attitudes of participants in case of signal loss were investigated. The study was conducted with 183 participants between February 4-12, 2020.Results: Most participants (58.2%) had more than 10 years of surgical experience and 36.6% performed more than 50 thyroidectomies annually. IONM was routinely used by 78.7% of the participants, whereas 16.4% reserved its use in difficult cases. Only 5.2% of the participants performed continuous monitoring. In case-based LOS scenarios, the majority of participants (approximately 60%) terminated the operation when the nerve was anatomically intact but LOS persisted, except in high-risk cancer cases. When the nerve anatomy was disrupted, most participants terminated the surgery, except for the high-risk cancer group. In cases of irreversible LOS with preserved nerve integrity, 58.9% of the patients preferred continuous vagus stimulation on the contralateral side, whereas 41.1% preferred intermittent nerve monitoring. Although 68.2% of the participants verbally informed the patients about the risks of LOS, only 24.4% provided this information on the consent form.The use of IONM in thyroid surgery is increasing in our country. However, there is still no consensus on the approach for staged thyroidectomy in cases of signal loss, and institutional and individual differences persist. Further studies are needed to determine the medical-legal implications and effects of these variations.