A prospective cross-sectional study on hypocalcemia after total thyroidectomy in patients with Graves' disease: insights on secondary hyperparathyroidism.

PURPOSE: To investigate the parathyroid function and calcium (Ca) levels in the secondary hyperparathyroidism (SHPT) state in patients with Graves' disease. METHODS: We examined 31 consecutive patients with Graves' disease without chronic kidney disease, who were treated with total thyroidectomy. The patients were divided into a normal parathyroid hormone (PTH) group (NPTH group; n = 19) with a PTH level ≤ 65 pg/mL, and a secondary hyperparathyroidism group (SHPT group; n = 12), with a PTH level > 65 pg/mL. The PTH and Ca-related parameters were examined and the risk factors for postoperative hypocalcemia were analyzed. RESULTS: The preoperative Ca level was significantly lower (2.24 ± 0.06 vs. 2.31 ± 0.07 mmol/L, p < 0.05) in the SHPT group than in the NPTH group. The reduction in PTH, 1,25-dihydroxyvitamin D (1,25(OH)2D), and Ca levels from the preoperative day to the next morning was significantly greater in the SHPT group than in the NPTH group (p < 0.05). When intraoperative factors were included, the decrease in the PTH level alone was significant. SHPT was a significant factor in determining the extent of PTH reduction. CONCLUSIONS: Hyperfunctioning parathyroid glands in the SHPT state were more susceptible to postoperative PTH reduction, which, combined with low preoperative Ca levels, increased the risk of postoperative hypocalcemia in patients with Graves' disease.

Usefulness of preoperative ice cream consumption and novel postoperative drainage management in patients undergoing left-sided neck dissection for thyroid cancer: a nonrandomized prospective study.

PURPOSE: This study investigated the effects of ice cream consumption on chyle leakage after left lateral neck dissection in patients with thyroid cancer. METHODS: A total of 491 patients with thyroid cancer underwent left lateral neck dissection with identification of the thoracic duct following ice cream consumption. Before closing the wound, the anesthesiologist increased the intrathoracic pressure to observe chyle leakage. If chyle leakage occurred postoperatively, the drain was removed using the drain negative pressure release test. RESULTS: Postoperative chyle leakage was observed in 18 of the 491 patients who underwent left lateral neck dissection. We treated 17 patients conservatively and 1 patient surgically. Drains were removed within five days in all patients. After the drain negative pressure release test had been performed in eight patients, the drainage volume significantly decreased from an average of 175 ml to 31 ml per day. The average number of days until the removal of the drainage tube was 3.2 days. No perioperative complications were associated with ice cream consumption. CONCLUSIONS: In left lateral neck dissection for thyroid cancer, performing surgery following ice cream consumption does not completely prevent chyle leakage; however, early drain removal is possible because there is only mild leakage.

Significant role of 1,25-dihydroxyvitamin D on serum calcium levels after total thyroidectomy: a prospective cohort study.

Introduction: Although active vitamin D (VD) has been used both preoperatively and postoperatively to prevent hypocalcemia risk in patients undergoing total thyroidectomy, the role of 1,25-dihydroxyvitamin D (1,25(OH)2D) has not been examined. This study comprehensively investigated the effects of 1,25(OH)2D on calcium (Ca) concentrations after total thyroidectomy. Methods: Serum Ca, parathyroid hormone (PTH), and 1,25(OH)2D levels were measured in 82 patients with thyroid disease before and after surgery. Results: Serum Ca, PTH, and 1,25(OH)2D levels decreased significantly on the morning of the first postoperative day. Notably, the decrease in 1,25(OH)2D concentration was significantly lower than that of PTH concentration (10.5 ± 33.4% vs. 52.1 ± 30.1%, p<0.0001), with 28% of patients showing increases in 1,25(OH)2D. The only factor predicting a postoperative 1,25(OH)2D decrease was a high preoperative 1,25(OH)2D concentration. Postoperative 1,25(OH)2D concentrations, as well as the magnitude and rate of decrease from preoperative levels, showed strong positive correlations with preoperative 1,25(OH)2D concentrations (p<0.0001 for all three variables) but not with PTH concentrations. These findings suggest that 1,25(OH)2D concentrations after thyroidectomy were more strongly dependent on preoperative concentrations than on the effect of PTH decrease and were relatively preserved, possibly preventing sudden severe postoperative hypocalcemia. A high 1,25(OH)2D level was the most important preoperative factor for hypocalcemia (<2 mmol/L; p<0.05) on the first postoperative day; however, only PTH decrease was statistically significant (p<0.001) when intraoperative factors were added. In the PTH >10 pg/mL group, the decrease in 1,25(OH)2D levels was significantly associated with postoperative hypocalcemia (p<0.05). Similarly, in the PTH levels >15 pg/mL group, a decrease in 1,25(OH)2D concentration was a significant factor, and the amount of PTH decrease was no longer significant. Conclusion: 1,25(OH)2D plays an important role in preventing sudden, severe hypocalcemia due to decreased PTH levels after total thyroidectomy, whereas high preoperative 1,25(OH)2D levels are a significant risk factor for postoperative hypocalcemia. Optimizing preoperative protocols to adjust Ca, PTH, and 1,25(OH)2D levels to improve the management of patients undergoing total thyroidectomy and to prevent extreme intraoperative PTH decreases may reduce the risk of hypocalcemia.

Intraoperative parathyroid hormone measurement pitfalls: parathyroid hormone spikes with carboxyl-terminal parathyroid hormone fragments in primary hyperparathyroidism-a case report.

BACKGROUND: Intraoperative parathyroid hormone (IOPTH) monitoring is a critical surgical adjunct for determining the extent of surgery for primary hyperparathyroidism (PHPT), with reported false-positive and false-negative rates of up to 10%. Surgeons must understand the parathyroid hormone (PTH) dynamics and select the appropriate IOPTH protocol and interpretation criteria for curative surgery. CASE PRESENTATION: We present the case of a 64-year-old woman with a large cystic parathyroid tumor and PHPT who experienced a significant delay in IOPTH decrease but was cured without additional surgery. The patient's basal intact PTH was 96.2 pg/mL, which decreased to 93.3 pg/mL at 25 min and 72.4 pg/mL at 55 min after removal of the parathyroid tumor. In an attempt to elucidate its pathophysiology, 1-84 PTH levels were measured in stored serum. These results can also be attributed to the relatively low basal PTH levels, intact PTH spike, and high ratio of large carboxyl-terminal PTH fragments present. The patient had normal intact PTH and calcium levels at the 9-month postoperative visit. CONCLUSIONS: As detailed reports on these phenomena are scarce, we discuss the causes of false-negative IOPTH results in terms of PTH production, secretion, metabolism, and differences in measurement methods to avoid unnecessary surgery.

[Preoperative diagnosis of nonrecurrent inferior laryngeal nerve--usefulness of CT and ultrasonography].

BACKGROUND AND OBJECT: The right nonrecurrent inferior laryngeal nerve (NRILN), which is usually associated with the right aberrant subclavian artery, is a risk factor of nerve injury during thyroid surgery. Therefore the presence of the NRILN should be diagnosed if possible before surgery. The aim of this study was to investigate the usefulness of computed tomography (CT) and ultrasonography (US) for preoperative diagnosis of the right-sided NRILN. SUBJECTS AND METHODS: We reviewed 1,561 patients who underwent thyroid surgery, during which the right inferior laryngeal nerve was exposed, at Yamashita thyroid and parathyroid clinic from April 2006 to April 2012. All medical records, CT findings and ultrasonograms of these patients were reviewed retrospectively. RESULTS: We recognized 11 patients who had the right-sided NRILN from the total of 1561 patients (0.71%). Ten of 1086 patients who underwent CT, had a right aberrant subclavian artery. CT findings were enabled us to predict the existence of the right NRILN before surgery. The sensitivity and specificity of CT for detection of the right-sided NRILN were 100% and 100%. On the other hand, we could detect the bifurcation of the innominate artery in 116 of 140 patients with cervical US before surgery, and therefore could confirm that the right inferior laryngeal nerve of the 116 patients was normal. The bifurcation of the other patients was not detectable and one of the 24 patients only had the right-sided NRILN during surgery. The sensitivity and specificity of cervical US for detection of the right-sided NRILN were 100% and 83.5% respectively. CONCLUSIONS: Although CT is extremely useful for preoperative diagnosis of the right-sided NRILN because of its accuracy, cervical US is also a good method for making sure that the right inferior laryngeal nerve is normal.

Orbital magnetic resonance imaging combined with clinical activity score can improve the sensitivity of detection of disease activity and prediction of response to immunosuppressive therapy for Graves' ophthalmopathy.

The aim of this study was to demonstrate that the addition of orbital magnetic resonance (MR) imaging can provide improvement in sensitivity of detection of active disease and the prediction of the response to intravenous glucocorticoid therapy (ivGC), over clinical activity score (CAS) alone. A prospective case series was studied at our institution. Forty eight patients were examined by CAS and orbital MR imaging. The maximum of T2 relaxation times of extraocular muscles (maxT2RT) and other parameters were evaluated by MR imaging. Thirty five of 48 patients underwent ivGC. Twenty of 35 patients, whose CAS was 2 points or less, were evaluated for the response to ivGC. The correlation between CAS and maxT2RT was evaluated. Differentiation of active and inactive GO was performed by CAS and orbital MR imaging. The response to ivGC was evaluated by CAS, orbital MR imaging and ophthalmic parameters. As a result, CAS and maxT2RT showed significant positive correlation (r=0.58, p<0.0001), and 15 patients were positive by CAS and orbital MR imaging. However, 20 patients were positive by only MR imaging. In those 20 patients, there was significant improvement after ivGC. We concluded that orbital MR imaging combined with CAS could improve the sensitivity of detection of active disease and the prediction of the response to ivGC. In addition, even if only one parameter of CAS is positive, further examination with orbital MR imaging is advised.

Surgically proven normocalcemic primary hyperparathyroidism: speculation of the possible role of estrogen in the etiology of this disease in premenopausal women.

We herein report a rare case of surgically proven normocalcemic primary hyperparathyroidism (NCHPT). A premenopausal 51-year-old woman was referred to our clinic because parathyroid adenoma was detected on neck ultrasonography (US). The patient's serum calcium concentration was 9.3 mg/dL and the intact parathyroid hormone (PTH) level was 128.8 pg/mL. The findings of almost all other examinations were also compatible with a diagnosis of NCHPT. Then, parathyroidectomy was performed. The serum calcium and PTH concentrations reduced significantly but remained within the normal ranges. A histological examination demonstrated parathyroid adenoma. A review of this case and the associated literature suggests that estrogen plays a significant role in the etiology of NCHPT in premenopausal women.

Idiopathic orbital myositis associated with Graves' disease.

A 52-year-old man was referred to our clinic. One week before his visit, he had complained of left eye pain and double vision. His clinical features were exacerbated. Despite the acute onset, which is atypical of thyroid eye disease (TED), TED was suspected due to the patient's history of Graves' disease (GD). After conducting clinical examinations and orbital magnetic resonance imaging, the patient was diagnosed with idiopathic orbital myositis (IOM), and intravenous glucocorticoid therapy was administered. After treatment, the patient's clinical manifestations dramatically improved. This is a rare case in that the history of GD made it difficult to differentiate IOM from TED.

Severe hypocalcemia complicated by postsurgical hypoparathyroidism and hungry bone syndrome in a patient with primary hyperparathyroidism, Graves' disease, and acromegaly.

We herein report a case of severe postsurgical hypocalcemia associated with primary hyperparathyroidism (pHPT), Graves' disease (GD) and acromegaly (AC). A 54-year-old woman was referred to our clinic for treatment of pHPT and GD. She also had active AC and was clinically diagnosed as multiple endocrine neoplasm type 1 because of pHPT and AC. Two enlarged parathyroid glands were detected by preoperative examinations. We performed total parathyroidectomy and thyroidectomy. After the operation, she showed severe hypocalcemia induced by postsurgical hypoparathyroidism and hungry bone syndrome. This is a rare case of postsurgical severe hypocalcemia associated with pHPT, GD and AC.