Thyroidectomy facilitated with Harmonic Caliper and intraoperative neural monitoring in three horses

Summary Background Thyroidectomy in horses is performed conventionally; however, both iatrogenic and post‐operative complications occur, mostly due to injury of the recurrent laryngeal nerve (RLN). Objective To facilitate sufficient understanding of the use of the Harmonic Focus® Shear (HFS) together with intraoperative neuromonitoring (IONM) of the RLN during thyroidectomy in horses. Study design Retrospective case series. Methods Three horses were presented with a thyroid mass, and a hemithyroidectomy was performed using the HFS together with IONM. Medical records were reviewed. Findings at short‐term follow‐up at 6 weeks after surgery and long‐term follow‐up obtained from the referring veterinarian or owner 3 years after surgery were evaluated. Results The horses were 9–17 years old. Thyroid enlargement was unilateral in all horses, with two on the left side and one on the right side. Histological findings were consistent with adenocarcinoma, C‐cell adenocarcinoma and adenoma in each horse. Neither intraoperative‐ nor post‐operative complications were encountered. Short‐ and long‐term follow‐up showed that all horses returned to previous activity. Main limitations The limitation of this study is the small sample size, reflecting the low prevalence of this disease and the rarity of this procedure in horses. Conclusions The use of the HFS and IONM enabled an easy, precise dissection, adequate haemostasis and direct visualisation of the RLN during thyroidectomy, avoiding its damage and allowing evaluation of its function intraoperatively.