Central lymph node dissection and permanent hypoparathyroidism after total thyroidectomy for papillary thyroid cancer: population-based study

Abstract

Background Papillary thyroid cancer is treated with total/near-total thyroidectomy (TT) with or without central lymph node dissection (CLND), depending on risk factors and tumour size. Balancing the risk of disease recurrence and surgical morbidity remains a challenge. A population-based nationwide study was undertaken to evaluate the risk of permanent hypoparathyroidism associated with CLND. Method Data on patients with stage pT1–3 papillary thyroid cancer, who underwent TT with or without CLND between 1 July 2004 and 30 June 2014 were retrieved from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery. Drug use was ascertained by cross-linking with the Swedish Prescribed Drug Register. Permanent hypoparathyroidism was defined as treatment with active D vitamin or oral calcium drugs for more than 6 months after surgery. Data were analysed separately for all patients and those who underwent TT + CLND. Univariable and multivariable logistic regression analyses were done, yielding odds ratios (ORs) with 95 per cent confidence intervals. Results A total of 722 patients were included in the study. Permanent hypoparathyroidism was more common in the TT + CLND group than the TT group: 30 of 265 patients (6·6 per cent) versus six of 457 (2·3 per cent) (P = 0·011). In multivariable logistic regression analysis, CLND was a risk factor for permanent hypoparathyroidism (OR 3·74, 95 per cent c.i. 1·46 to 9·59, based on use of combined therapy 6 months after surgery). In patients who had TT + CLND, node negativity was associated with a risk of permanent hypoparathyroidism (OR 3·08, 1·31 to 7·25). Conclusion CLND is an independent risk factor for permanent hypoparathyroidism. Node negativity is associated with a higher risk of permanent hypoparathyroidism.

Distribution of inadvertently excised parathyroid glands during thyroid surgery and the link with post-surgical hypoparathyroidism

“…This study identified a six-month post-surgical hypoparathyroidism or hypocalcaemia rate of 10.4 per cent, with the incidence rising to 19.8 per cent in those who had an inadvertent parathyroidectomy. The high incidence of sixmonth post-surgical hypoparathyroidism or hypocalcaemia in this cohort may be explained by the relatively high rate of central neck dissection (an independent risk factor for permanent hypoparathyroidism), 30 and the criteria used to define six-month post-surgical hypoparathyroidism or hypocalcaemia (patients requiring calcium or vitamin D supplements at six months).…”

Impact of Lymph Node Dissection on Postoperative Complications of Total Thyroidectomy in Patients with Thyroid Carcinoma

“…Similar results also have been observed in a large series of 1087 patients submitted to thyroidectomy alone, or thyroidectomy plus ipsilateral or bilateral CLND, in which the authors demonstrated that bilateral CLND had a significantly higher rate of permanent hypoparathyroidism [ 24 ]. Recently, Salem et al also demonstrated that CLND was a risk factor for permanent hypoparathyroidism (OR = 3.74, IC 95% [1.46–9.59]), based on the use of combined therapy 6 months after surgery [ 25 ]. Interestingly, they also found that node negativity was associated with a risk of permanent hypoparathyroidism (OR = 3.08, IC 95% [1.31–7.25]), suggesting that an extensive exploration of the central neck compartment might increase the risk of unintentional removal of the lower parathyroid glands.…”

Head and Neck Cancer: United Kingdom National Multidisciplinary Guidelines, Sixth Edition

“…Prophylactic level VI lymph node dissection is associated with a higher incidence of recurrent laryngeal nerve damage and long-term permanent hypoparathyroidism. 1054 It is therefore not routinely recommended, but it may be indicated in individuals with high-risk tumours.…”