RESUMEN
BACKGROUND: Staged thyroidectomy has been recommended when loss of the signal from intraoperative nerve monitoring is observed after first-side dissection of the recurrent laryngeal nerve. There is no high-quality evidence supporting this recommendation. In addition, it is not clear whether signal loss predicts postoperative vocal cord paralysis. METHODS: This was a prospective observational study of consecutive adult patients undergoing neuromonitored total thyroidectomy for either malignancy or multinodular goitre. The prevalence of first-side loss of signal was recorded. Surgery was completed, and vagus and laryngeal nerves on the first side were rechecked at the end of the procedure. RESULTS: Two-hundred and ninety patients were included. Loss of signal on the first side was noted in 16 procedures (5.5 per cent). Thyroidectomy was completed and, at retesting, 15 of 16 initially silent nerves recovered an electromyographic signal with a mean(s.d.) amplitude of 132(26) mcV. Mean time to recovery was 20.2 (range 10-35) min. In no patient was the signal lost on the opposite side. Only three of 15 nerves with a recovered signal were associated with transient vocal cord dysfunction. CONCLUSION: After loss of signal of the recurrent laryngeal nerve dissected initially, there was a 90 per cent chance of intraoperative signal recovery. In this setting, judicious bilateral thyroidectomy can be performed without risk of bilateral recurrent nerve paresis.
Asunto(s)
Monitoreo Intraoperatorio/métodos , Complicaciones Posoperatorias/etiología , Nervio Laríngeo Recurrente/cirugía , Tiroidectomía/métodos , Parálisis de los Pliegues Vocales/etiología , Adulto , Disección/métodos , Electromiografía , Femenino , Bocio Nodular/cirugía , Humanos , Masculino , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos , Recuperación de la Función/fisiología , Nervio Laríngeo Recurrente/fisiología , Traumatismos del Nervio Laríngeo Recurrente/prevención & control , Neoplasias de la Tiroides/cirugía , Parálisis de los Pliegues Vocales/fisiopatologíaRESUMEN
BACKGROUND: Although the variables that influence the development of post-thyroidectomy hypocalcaemia are now better understood, the risk factors and long-term outcome of persistent hypoparathyroidism (HPP) are poorly defined. A retrospective review of a prospective protocol for the management of post-thyroidectomy hypocalcaemia was performed. METHODS: Patients with a serum calcium level below 8 mg/dl (2 mmol/l) 24 h after total thyroidectomy were prescribed oral calcium with or without calcitriol and followed for at least 1 year. Protracted HPP was defined as an intact parathyroid hormone (iPTH) level below 13 pg/ml and need for calcium medication at 1 month after thyroidectomy. RESULTS: Of 442 patients (343 with goitre, 99 with carcinoma) undergoing total thyroidectomy, 222 (50.2 per cent) developed postoperative hypocalcaemia. Eleven patients were lost to follow-up. Parathyroid function recovered in 131 patients within 1 month and 80 developed protracted HPP, which was associated with lymphadenectomy, fewer than three glands left in situ and incidental parathyroidectomy. Parathyroid function recovered within 1 year in 78 per cent of patients with protracted HPP. Factors associated with late recovery of parathyroid function were higher serum calcium and low but detectable iPTH levels 1 month after surgery. These factors were associated with higher calcitriol and calcium dosages at hospital discharge. Parathyroid autotransplantation did not protect against permanent HPP. CONCLUSION: Higher serum calcium levels at 1 month after total thyroidectomy are associated with recovery of parathyroid function. It is hypothesized that intensive medical treatment of hypocalcaemia-'parathyroid splinting'-may improve the outcome of patients with protracted HPP.
