Adherence to international neural monitoring study group (INMSG) guidelines for intraoperative nerve monitoring in thyroid and parathyroid surgery. A survey of endocrine surgeons in Spain

Abstract Intraoperative nerve monitoring (IONM) provides real-time nerve feedback and easy identification, guiding surgical decisions in thyroid and parathyroid procedures. We assessed the practical implementation of the International Nerve Monitoring Study Group (INMSG) standard procedures, opinions, and training on IONM technology among endocrine surgeons in Spain. In 2021, the Spanish Association of Surgery emailed endocrine surgeons’ members an anonymous and voluntary web-based survey. We performed a descriptive analysis of responses. Half (49.6%, 112/226) completed the questionnaire. Survey results showed 79.4% follow INMSG guidelines (59.8% always, 19.6% sometimes). Observed deficiencies included low vagal stimulation before (49%) and after lobectomy (44%), and about 35%-42% lacked understanding of loss of signal (LOS) thresholds, risking recurrent laryngeal nerve (RLN) injury. Only 53.6% staged contralateral surgery for benign, and 26.8% for malignant tumours when LOS persisted. Just 5% provided IONM-specific informed consent. Most (70–80%) viewed IONM as beneficial and medico-legally supportive. Only 33.9% attended specific training courses in IONM. Although most Spanish endocrine surgeons reported compliance with INMSG standards for IONM in thyroid and parathyroid procedures, this contrasts with the real practice. Educational efforts and establishing IONM-specific informed consent are needed to prevent IONM misuse, patient harm, and inconsistencies that weaken scientific evidence.