Endocrine Abstracts

Methods: To evaluate factors influencing the relative risk (RR) for vocal fold paralysis we analyzed 3019 patients (69.5% female) having surgery for benign thyroid diseases (58.7% nodular goiter, 17.5% inactive nodes, 16.3% thyroid autonomy, 6.5% Grave’s disease). Operations were performed with intraoperative neuromonitoring by general surgeons (GS, n=1637) or physicians specially trained for ENT (n=1382). 19.2% of the procedures were carried out by residents in training.

Results: Vocal fold paralysis occurred in 198 subjects (6.6%), 6.3% in females and 7.0% in males. Prevalence was not influenced by gender, age, recurrent disease (RR 1.20), surgeries performed by physicians in training (6.2%, n=581) or if minimal invasive (6.5%, n=769) and conventional surgery (6.6%, n=2250) were compared. Risk was increased in nodular goiter (7.3%, RR 1.37), but not in Grave’s disease (6.6%, RR 1.01). A higher rate was seen in total (n=1576, 6.9%) and nearly total (n=507, 8.1%) than in subtotal thyroidectomy (n=866, 5.2%). A lower rate (RR 0.54) was observed in operations performed by ENT (4.6%) than by GS (8.2%). Postoperative haemorrhage (4.6% vs. 1.6%, RR 2.94), hypocalcemia < 2.0 mmol/l (28.8% vs. 19.9%, RR 1.63) and the need for calcium substitution (RR 1.65) or dihydrotachysterol treatment (RR 2.18) at discharge from the hospital was documented more frequently in patients with laryngeal nerve palsy.

Conclusion: In thyroid surgery a multinodular goiter, invasiveness of the operations and a physician not trained for head and neck surgery are risk factors for vocal fold paralysis. Postoperative haemorrhage and hypocalcemia are seen more frequently in patients with damage to the recurrent laryngeal nerve.