Central Compartment Nodal Bulk: A Predictor of Permanent Postoperative Hypocalcaemia

Central compartment clearance (CCC) for Papillary thyroid cancers (PTC) is one of the factors causing postoperative hypocalcaemia. We aimed to examine determinants of this major sequela. 41 patients treated for PTCs between 2014 and 2016 were studied. Surgical details, tumour and nodal characteristics, incidence of transient, temporary and permanent hypocalcaemia were noted. Central clearance was done bilaterally in 24 (58.5%) cases, ipsilaterally in 17 (41.6%). Central nodes were involved in 26 (63.4%) cases, unilaterally in 15 (36.6%), bilaterally in 11 (26.8%). Transient hypocalcaemia developed in 10 (24.4%) cases, temporary hypocalcaemia in 6 (14.6%) cases, and permanent hypocalcaemia in 2 (4.9%) cases. 17 (41%) patients were symptomatic. 9 (21.9%) patients received intravenous calcium. The only factor consistently associated with development of hypocalcaemia of all patterns, was the presence of matted central compartment nodes (p = 0.021). Matted nodes also related to a longer length of stay (p = 0.04) and requirement of intravenous calcium (p = 0.000). Extent of CCC, nodal yield, nodal positivity, perinodal extension, number of parathyroids identified, gender or pT size were not significantly associated. Symptomatic patients did not necessarily become permanently hypocalcaemic (p = 0.8). Patients requiring intravenous calcium were more likely to take oral calcium after discharge (p = 0.002). Postoperative hypocalcaemia is more likely in cases with bulky involved central nodes where extensive clearance is done. In routine CCC, even if done bilaterally, preservation of parathyroid function is possible. Permanent hypocalcaemia after CCC need not be taken as inevitable.