Severe Hypocalcemia After Thyroidectomy: An Analysis of 7366 Patients.

OBJECTIVE: The aim of the study was to determine severe hypocalcemia rate following thyroidectomy and factors associated with its occurrence. BACKGROUND: Hypocalcemia is the most common complication after thyroidectomy. Severe post-thyroidectomy hypocalcemia can be life-threatening; data on this specific complication are scarce. METHODS: Patients who underwent thyroidectomy in the American College of Surgeons-National Surgical Quality Improvement Program thyroidectomy-targeted database (2016-2017) were abstracted. A severe hypocalcemic event was defined as hypocalcemia requiring intravenous calcium, emergent clinic/hospital visit, or a readmission for hypocalcemia. Multivariable regression was used to identify factors independently associated with occurrence of severe hypocalcemia. RESULTS: Severe hypocalcemia occurred in 5.8% (n = 428) of 7366 thyroidectomy patients, with 83.2% necessitating intravenous calcium treatment. Rate of severe hypocalcemia varied by diagnosis and procedure (0.5% for subtotal thyroidectomy to 12.5% for thyroidectomy involving neck dissections). Overall, 38.3% of severe hypocalcemic events occurred after discharge; in this subset, 59.1% experienced severe hypocalcemia despite being discharged with calcium and vitamin D. Severe hypocalcemia patients had higher rates of recurrent laryngeal nerve injury (13.4% vs 6.6%), unplanned reoperations (4.4% vs 1.3%), and longer hospital stay (30.4% vs 6.2% ≥3 days (all P < 0.01). After multivariate adjustment, severe hypocalcemia was associated with multiple factors including Graves disease [odds ratio (OR) = 2.06], lateral neck dissections (OR: 3.10), and unexpected reoperations (OR = 3.55); all P values less than 0.01. CONCLUSIONS: Severe hypocalcemia and suboptimal hypocalcemia management after thyroidectomy are common. Patients who experienced severe hypocalcemia had higher rates of nerve injury and unexpected reoperations, indicating surgical complexity and provider inexperience. More biochemical surveillance particularly a parathyroid hormone-based protocol, fine-tuned supplementation, and selective referral could reduce occurrence of this morbid complication.

Surgical Hypoparathyroidism.

Surgical hypoparathyroidism is the most common cause of hypoparathyroidism and the result of intentional or inadvertent extirpation, trauma, or devascularization of the parathyroid glands. Surgical hypoparathyroidism may present as a medical emergency. Pediatric patients, those with Graves disease, and those undergoing extensive neck dissections or reoperative neck surgery are at particular risk for this complication. Extensive surgical expertise, immediate or delayed autotransplantation, and prophylactic and postoperative calcium/vitamin D supplementation in select patients are associated with a reduction in the risk of surgical hypoparathyroidism. Intraoperative parathyroid imaging is among novel strategies being investigated to mitigate surgical hypoparathyroidism in the intraoperative setting.

Insular thyroid cancer: a population-level analysis of patient characteristics and predictors of survival.

BACKGROUND: Insular thyroid cancer (ITC) is an uncommon, poorly differentiated thyroid malignancy. To date, there have been no population-level studies of the characteristics and outcomes of patients with ITC. METHODS: The authors used the Surveillance, Epidemiology, and End Results (SEER) database from 1999 to 2007 to compare the characteristics and prognosis of patients who had ITC with those of patients who had well differentiated thyroid cancer (WDTC) and anaplastic thyroid cancer (ATC). Data analyses were performed using chi-square tests, analyses of variance, log-rank tests, and multivariate regression. RESULTS: There were 114 patients with ITC, 497 patients with ATC, and 34,021 patients with WDTC. The mean age of patients with ITC was 62.1 years versus 48.1 years for patients with WDTC and 69.5 years for patients with ATC (P < .001). The mean ITC tumor size was 5.9 cm versus 2.0 cm for WDTC and 6.4 cm for ATC (P < .001). Distant metastasis occurred in 31% of patients with ITC versus 4.5% of patients with WDTC and 59.1% of patients with ATC (P < .001). Insular histology was associated independently with compromised survival in the overall study sample (hazard ratio [HR], 2.1; P = .001). The 5-year disease-specific survival rate was 72.6%, 97.2%, and 9.1% for patients with ITC, WDTC, and ATC, respectively (P < .001). After adjustment, radioiodine therapy (HR, 0.15; 95% confidence interval, 0.04-0.5) and distant metastasis (HR, 15.3; 95% confidence interval, 3.7-62.2) were associated independently with ITC survival. The mortality rate was 7.1%, 12%, and 54.3% for patients with localized, regional, and distant stage ITC, respectively (P < .001). For patients who had ITC with distant metastasis, thyroidectomy and radioiodine therapy independently improved survival. CONCLUSIONS: ITC is rare and aggressive. The current results indicated that its treatment should include total thyroidectomy and high-dose radioiodine for all patients and neck dissections for patients with lymph node disease. Early diagnosis and close surveillance are essential in the management of patients with ITC.