The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) as a consequence of neck dissection

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) canhave multiple causes. Surgical neck dissections may have an association with this syndrome and represent the basis for this study. A retrospective review of 50 patients undergoing neck dissections was performed to evaluate for the development of hyponatraemia as a consequence of SIADH. Based on the results of this review, a prospective study of 20 consecutive patients undergoing 22 neck dissections was performed to determine the incidence ofSIADH. A control group of 25 consecutive patients undergoing major non-neck dissection surgery was also studied. SIADH developed in nine of 50 patients (18 per cent) of our retrospective group with a high incidence of development in those who had jugular vein ligation (JVL) (22 per cent), pre-operative radiation therapy (25 per cent) or squamous cell cancers (32 per cent). SIADH developed in six patients undergoing 22 neck dissections (27 per cent) in our prospective group. A high incidence was also noted for those with JVL (42 per cent), pre-operative radiation therapy (67 per cent) or squamous cell cancer (40 per cent). No patients developed symptomatic hyponatraemia. No patients in the prospective control group developed SIADH. Neck dissection surgery is associated with a significant risk for the development of SIADH. Factors such as jugular vein ligation (JVL), pre-operative radiotherapy and squamous cell cancer appear to increase this risk.