Systematic review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia

Stratifying the Risk of Developing Clinical Hypocalcemia after Thyroidectomy with Parathyroid Hormone

Objective

To identify the risk of clinical hypocalcemia in the first hours after thyroidectomy.

Study Design

Prospective observational study.

Setting

Single-institution tertiary hospital in Madrid, Spain.

Subjects and Methods

A total of 123 patients who underwent total or completion thyroidectomy between June 2010 and March 2012 were included. Pre- and postoperative intact parathyroid hormone (iPTH) levels were obtained. Patients remain hospitalized a minimum of 48 hours until blood calcium stabilized. Calcium and/or vitamin D supplements were prescribed only when signs or symptoms of hypocalcemia developed. Receiver operating characteristic curve analysis was employed to evaluate the postoperative iPTH level and the pre- to postoperative decrease in iPTH levels. Two cutoff values were determined to stratify the risk of developing clinical hypocalcemia into 3 groups.

Results

The areas under the receiver operating characteristic curve were 0.991 for the postoperative iPTH and 0.998 for the decrease in iPTH. An iPTH decrease of 80% had 100% sensitivity to detect patients who developed clinical hypocalcemia, while a postoperative iPTH <3 pg/mL had 100% specificity. Thus, patients with an iPTH decrease ≤80% are at a very low risk of clinical hypocalcemia, and patients with a postoperative iPTH <3 pg/mL are at a very high risk. Patients with an iPTH decrease >80% and a postoperative iPTH ≥3 pg/mL are at intermediate risk. No significant correlation was found between the time when the sample was obtained and iPTH values.

Conclusion

This study stablishes a very accurate test to stratify the risk of clinical postthyroidectomy hypocalcemia based on pre- and postoperative iPTH levels.

Prolonged Duration of Surgery Predicts Postoperative Hypoparathyroidism among Patients Undergoing Total Thyroidectomy in a Tertiary Referral Centre

BACKGROUND

Postoperative hypoparathyroidism is a common complication following total thyroidectomy. The aim of this study was to investigate the incidence of both transient and permanent hypoparathyroidism in patients undergoing total thyroidectomy in a tertiary referral centre and, furthermore, to identify early predictive risk factors.

METHODS

Based on a single-institution retrospective review, we identified 582 patients who underwent total thyroidectomy between January 2010 and March 2015. Information on age, gender, pathological diagnosis, duration of surgery, autotransplantation of parathyroid glands, neck dissection, and experience and position of the surgeon was retrieved from the medical records. Furthermore, serum levels of parathyroid hormone and calcium were registered pre- and postoperatively and after 3 and 12 months.

RESULTS

The incidence of transient hypoparathyroidism during the first 24 h and 3 months after surgery was 47.8 and 17.8%, respectively. Furthermore, the incidence of permanent hypoparathyroidism 1 year after surgery was 10.7%. A prolonged duration of surgery was significantly associated with hypoparathyroidism. Moreover, autotransplantation of parathyroid glands was a significant predictor of transient hypoparathyroidism after 24 h and 3 months, but was not associated with permanent hypoparathyroidism.

CONCLUSIONS

Transient and permanent hypoparathyroidism is common among patients undergoing total thyroidectomy in a tertiary referral centre. A duration of surgery >120 min constitutes an independent risk factor due to the risk of ischaemic damage. Regain of function of devascularized parathyroid glands must be expected to last at least 1 year postoperatively. Furthermore, the recovery of autotransplanted parathyroid glands should not be evaluated within 1-3 months after surgery.

Hypoparathyroidism

Hypoparathyroidism is a disease characterized by inadequately low circulating concentrations of parathyroid hormone (PTH) resulting in low calcium levels and increased phosphate levels in the blood. Symptoms of the disease result from increased neuromuscular irritability caused by hypocalcaemia and include tingling, muscle cramps and seizures. The most common cause of the disease is inadvertent removal of, or injury to, the parathyroid glands during neck surgery, followed by genetic, idiopathic and autoimmune aetiologies. Conventional treatment includes activated vitamin D and/or calcium supplements, but this treatment does not fully replace the functions of PTH and can lead to short-term problems (such as hypocalcaemia, hypercalcaemia and increased urinary calcium excretion) and long-term complications (which include nephrocalcinosis, kidney stones and brain calcifications). PTH replacement has emerged as a new treatment option. Clinical trials using human PTH(1-34) and PTH(1-84) showed that this treatment was safe and effective in studies lasting up to 6 years. Recombinant human PTH(1-84) has been approved in the United States and Europe for the management of hypoparathyroidism; however, its effect on long-term complications is still being evaluated. Clinical practice guidelines, which describe the consensus of experts in the field, have been published and recognize the need for more research to optimize care. In this Primer, we summarize current knowledge of the prevalence, pathophysiology, clinical presentation and management of hypoparathyroidism.

Evaluating the effectiveness of prophylactic central neck dissection with total thyroidectomy for cN0 papillary thyroid carcinoma: An updated meta-analysis

BACKGROUND

The effectiveness of prophylactic central neck dissection (pCND) following total thyroidectomy (TT) in patients with clinical node-negative (cN0) papillary thyroid carcinoma (PTC) is still controversial. The aim of this meta-analysis is to evaluate the outcome of pCND and to provide quantitative evidence.

METHOD

A detailed literature search of PubMed, EMBASE, ClinicalTrails.gov and Cochrane Library electronic databases for articles published up to October 2016 was carried out. This meta-analysis was performed by the random method (Mantel-Haenszel) model. Locoregional recurrence (LRR) and surgical complications were analyzed.

RESULTS

Twenty-two studies comparing pCND + TT (combined) and TT alone in cN0 PTC patients were analyzed. A total of 6930 cases were enrolled, including 2381 cases in the combined group and 4009 cases in the TT-alone group. Compared with TT alone, patients in the combined group showed a significantly lower rate of overall LRR (OR = 0.66, 95% CI = 0.48-0.89) and central compartment recurrence (OR = 0.40, 95% CI = 0.22-0.73). There was no statistical difference in the rate of lateral compartment recurrence. However, the combined group showed a significantly higher rate of temporary and permanent hypoparathyroidism (OR = 2.28, 95% CI = 1.92-2.27/OR = 1.84, 95% CI = 1.15-2.95) and temporary recurrent laryngeal nerve injury (LNR) (OR = 1.53, 95% CI = 1.08-2.16). There was no statistical difference in the rate of permanent LNR, hematoma, hemorrhage or wound infection.

CONCLUSIONS

This meta-analysis revealed that pCND with TT was a significantly efficient way to reduce the risk of LRR. However, pCND + TT increased the incidence rate of temporary and permanent hypoparathyroidism and temporary LNR.

Postoperative Outcomes in Graves' Disease Patients: Results from the Nationwide Inpatient Sample Database

BACKGROUND

Current surgical indications for Graves' disease include intractability to medical and/or radioablative therapy, compressive symptoms, and worsening ophthalmopathy. Total thyroidectomy for Graves' disease may be technically challenging and lead to untoward perioperative outcomes. This study examines outcomes in patients with Graves' disease who underwent total thyroidectomy and assesses its safety for this patient population.

METHODS

A retrospective cross-sectional analysis was performed using the Nationwide Inpatient Sample database from 2006 to 2011. Total thyroidectomy performed in patients with Graves' disease, benign multinodular goiter (MNG), and thyroid cancer was identified. Demographic factors, comorbidities, and postoperative complications were evaluated. Chi-square, one-way analysis of variance, and risk-adjusted multivariable logistic regression were performed.

RESULTS

Of 215,068 patients who underwent total thyroidectomy during the study period, 11,205 (5.2%) had Graves' disease, 110,124 (51.2%) MNG, and 93,739 (43.6%) thyroid malignancy. Patients with Graves' disease were younger than MNG and thyroid cancer patients (M_age = 42.8 years vs. 55.5 and 51.0 years; p < 0.01). The Graves' disease group included a higher proportion of women (p < 0.01) and nonwhites (p < 0.01). Postoperatively, Graves' patients had significantly higher rates of hypocalcemia (12.4% vs. 7.3% and 10.3%; p < 0.01), hematomas requiring reoperation (0.7% vs. 0.4% and 0.4%; p < 0.01), and longer mean hospital stay (2.7 days vs. 2.4 and 2.2 days; p < 0.01) compared to MNG and thyroid cancer patients, respectively. On risk-adjusted multivariate logistic regression, Graves' disease was independently associated with a higher risk of vocal-cord paralysis (odds ratio [OR] = 1.36 [confidence interval (CI) 1.08-1.69]), tracheostomy (OR = 1.35 [CI 1.1-1.67]), postoperative hypocalcemia (OR = 1.65 [CI 1.54-1.77]), and hematoma requiring reoperation (OR = 2.79 [CI 2.16-3.62]) compared to MNG patients. High-volume centers for total thyroidectomy were independently associated with lower risk of postoperative complications, including in patients with Graves' disease.

CONCLUSIONS

Despite low overall morbidity following total thyroidectomy, Graves' disease patients are at increased risk of postoperative complications, including bleeding, vocal-cord paralysis, tracheostomy, and hypocalcemia. These risks appear to be lower when performed at high-volume centers, and thus referral to these centers should be considered. Total thyroidectomy may therefore be a safe treatment option for appropriately selected patients with Graves' disease when performed by experienced surgeons.

Long-term treatment-related morbidity in differentiated thyroid cancer: a systematic review of the literature

Background

Differentiated thyroid cancer (DTC) occurs in relatively young patients and is associated with a good prognosis and long survival. The management of this disease involves thyroidectomy, radioiodine therapy, and long-term thyroid-stimulating hormone suppression therapy (THST). The long-term effects of the treatment and the interaction between subclinical hyperthyroidism and long-term hypoparathyroidism are poorly understood. This review sought to examine the available evidence.

Methods

A PubMed search was carried out using the search terms “Thyroid Neoplasms” AND (“Thyroxine” OR “Hypocalcemia” OR “Thyrotropin”). Original English language articles published in the last 30 years studying the morbidity from thyroid-stimulating hormone (TSH) suppression and hypoparathyroidism following a surgery for DTC were retrieved and reviewed by 2 authors.

Results

Of the 3,000 results, 66 papers including 4,517 patients were selected for the present study. Studies reported on a range of skeletal (included in 34 studies, 1,647 patients), cardiovascular (17 studies, 957 patients), psychological (10 studies, 663 patients), and other outcomes (10 studies, 1,348 patients). Nine of 26 studies on patients who underwent THST showed a reduction in bone density, and 13 of 23 studies showed an increase in bone turnover markers. Skeletal effects were more marked in postmenopausal women. There was no evidence of increased fracture risk, and only little data were available on hypoparathyroidism. Four of five studies showed an increased left ventricular mass index on echocardiography, and one study showed a higher prevalence of atrial fibrillation (AF). There was little difference in basic physiological parameters and limited literature regarding symptoms or significant events. Six studies showed associations between long-term TSH suppression and impaired quality of life. Impaired glucose metabolism and prothrombotic states were also found in DTC patients.

Conclusion

There is limited literature regarding long-term DTC treatment-related morbidity, particularly regarding the effects of long-term hypocalcemia. Most studies have focused on surrogate markers and not on clinical outcomes. A large prospective study on defined clinical outcomes would help characterize the morbidity of treatment and stimulate research on tailoring treatment strategies.

Preoperative vitamin D deficiency and postoperative hypocalcemia in thyroid cancer patients undergoing total thyroidectomy plus central compartment neck dissection

Background

There appears to be a lack of consensus whether preoperative vitamin D deficiency (VDD) increases the risk of postoperative hypocalcemia and decreases the accuracy of postoperative parathyroid hormone (PTH) in predicting hypocalcemia in thyroid cancer patients undergoing total thyroidectomy (TT) plus central compartment neck dissection (CCND). This study aims to address these issues.

Method

All consecutive thyroid cancer patients who underwent TT plus CCND were retrospectively reviewed through a prospectively collected database between October 2015 and April 2016 in a tertiary referral hospital. The multivariate analysis was performed to identify the significant predictors for hypocalcemia. Receiver operator characteristic curve (ROC) was created and the area under the ROC was used to evaluate the predictive accuracy of postoperative PTH and compared between patients with or without VDD.

Results

A total of 186 patients were included. The incidence of VDD was 73.7% (137 patients). The incidence of biochemical and symptomatic hypocalcemia was similar in patients with or without VDD (P = 0.304 and 0.657, respectively). Multivariate analysis showed that only postoperative PTH was an independent predictor of symptomatic hypocalcemia (OR = 8.05, 95%CI = 3.99-16.22; P = 0.000). The area under the ROC was similar between patients with preoperative vitamin D level < 20 and ≥20 ng/mL (0.809 versus 0.845, P = 0.592).

Conclusion

VDD was not a significant risk factor for hypocalcemia following TT+CCND, and did not affect the accuracy of postoperative PTH as a predictor of postoperative hypocalcemia. Thus, routine preoperative screening for vitamin D seems to be unnecessary.

Can Parathormon Levels after Ipsilateral Lobectomy Predict Postoperative Hypocalcemia in Patients Undergoing Total Thyroidectomy?

The purpose of this study was to investigate the relationship between the serum parathormone (PTH) levels measured after completion of hemithyroidectomy on the first side during total thyroidectomy and the postoperative hypocalcemia. The patients were divided into two groups, as those who demonstrated a decrease in PTH levels measured after completion of hemithyroidectomy of the first side (Group 1, n = 43) and those who did not demonstrate a decrease in PTH levels (Group 2, n = 24). The serum PTH levels were measured just before the incision (PTHi), when the hemithyroidectomy stage had been completed (PTHht), at the end of the operation (PTHtt), and at the postoperative 24th hour (PTH24hr). The serum total calcium (Ca21) levels were also measured. The median percentage differences in PTHtt levels based on basal PTHi levels of Groups 1 and 2 were -60.6 and -15.7 per cent, respectively, P = 0.001. The frequency of postoperative biochemical hypocalcemia was higher in Group 1, P < 0.05. It was determined that a 10 per cent or higher decrease in PTHht levels in Group 1 could predict biochemical hypocalcemia at the postoperative 24th hour. In conclusions, postoperative hypocalcemia is seen more frequent in patients with a decrease of PTHht during total thyroidectomy. A decrease of 10 per cent in PTHht levels measured after ipsilateral lobectomy and a 62 per cent or higher decrease in PTHtt levels measured in the end of the total thyroidectomy could be helpful for prediction of postoperative hypocalcemia in these patients.

Early discharge after total thyroidectomy: a retrospective feasibility study

AIM

The continued hospitalization after total thyroidectomy is often due to the onset of hypocalcemic complications more than 24 hours after surgery. So it would be important to predict which patients will not develop the hypocalcemic complication to discharge them early. This was the aim of our study.

PATIENTS AND METHODS

Our retrospective study was conducted on 327 consecutive thyroidectomized patients, operated on for benign and malignant diseases. We evaluated the values of preoperative serum calcium levels (Cal0) and of the first postoperative day (Cal1) and two new variables were calculated (dCal and dCaln). The same thing was made on a subgroup of 111 patients in whom also parathiroyd hormone (PTH) values were detected. Statistical analysis was performed with the goal of determining if we could establish a safe criterion for discharge at 24 hours after surgery and if there is a correlation between suitability for discharge and diagnosis.

RESULTS

As to discharge, the predictive power of the discriminant function applied was significant both on the total of patients and in the subgroup of 111 patients, but it was clinically unacceptable because it would expose us to a 21% to 27% error rate. It is not possible to identify a threshold, below which to consider patients surely dischargeable. The diagnosis does not appear correlated with the suitability for discharge.

CONCLUSION

On the basis of serum calcium and PTH levels in the first postoperative day, it is impossible to predict which patients can be discharged 24 hours after surgery without incurring in hypocalcemic complications.

Preoperative vitamin D level as predictor of post-thyroidectomy hypocalcemia in patients sustaining transient parathyroid injury

BACKGROUND

Several studies have sought to identify predictors of postoperative hypocalcemia after total thyroidectomy; however, there have been conflicting results regarding the impact of preoperative vitamin D deficiency.

METHODS

The medical records of patients undergoing total thyroidectomy were retrospectively reviewed. The number of parathyroid glands identified or reimplanted at the time of surgery was used as a marker of transient parathyroid gland damage.

RESULTS

Sixty-seven patients were included in the study. Vitamin D deficiency was a significant predictor of hypocalcemia in patients in whom ≥3 parathyroid glands were identified, but not in patients in whom 0-2 parathyroid glands were identified intraoperatively (odds ratio [OR] 5.8; P = .036).

CONCLUSION

Vitamin D deficiency is a significant predictor of postoperative hypocalcemia in patients in whom ≥3 parathyroid glands are identified intraoperatively, but not in patients who sustain minimal transient damage to the parathyroid glands.

Perioperative Management of Thyroid Dysfunction

Due to the manifold effects of thyroid hormone across virtually all organ systems, the complications associated with thyroid dysfunction are numerous and diverse. The stresses encountered during the perioperative period may exacerbate underlying thyroid disorders, potentially precipitating decompensation and even death. Thus, it is of the utmost importance for the clinician to comprehend the mechanisms by which thyroid disease may complicate surgery and postoperative recovery and to be cognizant of the most effective means of optimizing the status of thyrotoxic and hypothyroid patients perioperatively. This article describes the adverse effects of thyroid dysfunction as they relate to the patient undergoing both thyroid and nonthyroid surgery and recommends treatment approaches aimed at decreasing perioperative risk.

The use of near-infrared fluorescence imaging in endocrine surgical procedures

Near-infrared fluorescence imaging in endocrine surgery is a new, yet highly investigated area. It involves indocyanine green use as well as parathyroid autofluorescence. Several groups have described their technique and reported on the observed utility. However, there is no consensus on technical details. Furthermore, the correlation between intraoperative findings and postoperative outcomes is unclear. With this study, we aim to review the current literature on fluorescence imaging and share our insights on technical details.

The Association of Discolored Parathyroid Glands and Hypoparathyroidism Following Total Thyroidectomy

BACKGROUND

It remains uncertain whether a parathyroid gland (PG) that appears darkened or severely bruised but still has an attached vascular pedicle should be left in situ or taken out and auto-transplanted following total thyroidectomy. Our study aimed to examine the impact of discolored PGs (DPGs) on short- and long-term hypoparathyroidism.

METHODS

One hundred and three patients who underwent total thyroidectomy with 4 clearly identified PGs were analyzed. Location (superior/inferior) and color of each PG were recorded. Patients without DPG were grouped into I while those with 1-2 DPGs and ≥3 DPGs were grouped into II and III, respectively. Transient hypoparathyroidism meant adjusted Ca <2.00 mol/L 24 h after surgery and/or need for supplements. Protracted hypoparathyroidism meant a subnormal PTH at 4-6 weeks and/or supplements >6 weeks. Permanent hypoparathyroidism meant supplements ≥1 year.

RESULTS

Relative to I, group III had greater adjusted Ca drop at postoperative 1-h (p = 0.012), 24-h (p < 0.001) and lower day-1 PTH (p = 0.015). Having ≥3 DPGs (OR 14.00, 95 % CI 1.575-124.474, p = 0.018) was an independent factor of transient hypoparathyroidism. However, permanent hypoparathyroidism rate was higher than in group I than II (p = 0.019). Eight patients (25.8 %) in group I had undetectable day-1 PTH, while none in group III had undetectable day-1 PTH. Graves' disease/toxic goiter (OR 15.166, 95 % CI 2.594-88.661, p = 0.003) and excised gland weight (OR 1.028, 95 % CI 1.010-1.046, p = 0.003) were independent factors of ≥3 DPGs.

CONCLUSIONS

PG discoloration is associated with transient hypoparathyroidism while normal colored PG with seemingly adequate blood supply does not always imply functionally normal gland. These findings highlights the need for a real-time intraoperative method to assess PG viability.

Postoperative hypomagnesaemia is not associated with hypocalcemia in thyroid cancer patients undergoing total thyroidectomy plus central compartment neck dissection

BACKGROUND

The literature remains scarce and controversial regarding the association of hypomagnesaemia and hypocalcemia after total thyroidectomy. This study aims to assess this association in thyroid cancer patients underwent total thyroidectomy (TT) plus central compartment neck dissection (CCND).

METHOD

All consecutive thyroid cancer patients who underwent TT plus CCND were retrospectively reviewed through a prospectively collected database between October 2015 and June 2016 in a tertiary referral hospital. The univariate and multivariate analysis were performed to identify the significant predictors for hypocalcemia.

RESULTS

A total of 237 patients were included. The incidence of postoperative biochemical and symptomatic hypocalcemia was 52.3% (124 patients) and 33.8% (80 patients), respectively. Multivariate analysis showed that only postoperative hypoparathyroidism was an independent predictor for biochemical hypocalcemia (HR = 14.37, 95%CI = 6.07-34.0; P < 0.000), while parathyroid gland autotansplantation (HR = 2.02, 95%CI = 1.04-3.91; P = 0.038) and hypoparathyroidism (HR = 7.47, 95%CI = 3.84-14.5; P < 0.000) were independent risk factor for symptomatic hypocalcemia. Postoperative hypomagnesaemia was not significantly associated with the development of hypocalcemia (P > 0.05).

CONCLUSION

Postoperative hypomagnesaemia was not an independent predictor of hypocalcemia after total thyroidectomy. It seems to be unnecessary to routinely monitor the magnesium levels before and after thyroid surgery.

Failure of fragmented parathyroid gland autotransplantation to prevent permanent hypoparathyroidism after total thyroidectomy

PURPOSE

Parathyroid autotransplantation during total thyroidectomy leads to higher rates of postoperative hypocalcaemia. It has been argued, however, that it prevents permanent hypoparathyroidism. The impact of autografted normal parathyroid gland fragments on long-term parathyroid status has not been assessed properly. To clarify this, the short- and long-term parathyroid function was assessed in patients with three glands remaining in situ after total thyroidectomy, in whom the fourth gland was either autotransplanted (Tx) or accidentally resected (AR).

METHODS

Consecutive patients (n = 669) undergoing first-time total thyroidectomy were prospectively studied recording the number of parathyroid glands remaining in situ: PGRIS =4-(glands autografted + glands in the specimen). The study was focused on the subgroup of 186 patients with three parathyroid glands remaining in situ as a result of either accidental resection (AR, n = 76) or autotransplantation into the sternocleidomastoid muscle (Tx, n = 110). Prevalence of postoperative hypocalcaemia, protracted, and permanent hypoparathyroidism were compared between the two groups. Demographic, disease-related, laboratory, and surgical variables were recorded. All patients were followed for at least 1 year.

RESULTS

Both groups were comparable in terms of disease and extent of surgery. Mean postoperative serum calcium was the same (AR: 1.97 ± 0.2 vs Tx: 1.97 ± 0.22 mmol/L). Rates of protracted (AR: 24% vs Tx: 25.5%) and permanent hypoparathyroidism (AR: 5.3% vs Tx: 7.3%) were similar in both groups.

CONCLUSIONS

The prevalence of parathyroid failure syndromes after total thyroidectomy was similar whether a parathyroid gland was inadvertently excised or autotransplanted. Autotransplantation did not influence the permanent hypoparathyroidism rate.

INCIDENTAL PARATHYROIDECTOMY DURING THYROID SURGERY - RISK, PREVENTION AND CONTROVERSIES; AN EVIDENCE-BASED REVIEW

Background

Postoperative hypocalcemia after thyroid surgery has a high prevalence ( 16-55% in different series). Incidental parathyroidectomy (IP) is a less discussed complication of thyroidectomy with consequences not properly defined. The aim of our study was to find incidence, risk factors and how to prevent IP.

Methods

Extensive search of English literature publications via PubMed was performed and 73 papers from 1980 to 2017 were analysed using the GRADE system/classification, quality of evidence was classified as "strong" when the result is highly unlikely to change existing recommendation and "weak" when opposite.

Results

Incidence of IP is 3.7-24.9%, while prevalence of permanent hypoparathyroidism is less frequent 6-12%. Direct relation between IP and hypoparathyroidism/hypocalcemia remains controversial. Female patients, ectopic parathyroids, small thyroids, Graves', malignancy, redo surgeries and total thyroidectomy favour IP. Routine visualization of parathyroids, new hemostatic devices, magnifying instruments and fluorescence can prevent incidental removal of parathyroids. Incidence of IP during videoassisted or robotic thyroidectomies was similar to open procedures. High volume, experienced and younger surgeons have lower complication rates (including hypoparathyroidism).

Conclusions

Incidental parathyroidectomy is more frequent than we might have expected. It should be avoided and parathyroid glands should be kept in situ. Majority of studies are retrospective (low degree of evidence according to previous mentioned GRADE classification) and further meta-analysis or randomized control studies are welcome in order to define the impact of incidental removal of parathyroids on postoperative outcome.

Indocyanine green fluorescence angiography for quantitative evaluation of in situ parathyroid gland perfusion and function after total thyroidectomy

BACKGROUND

Because the fluorescent light intensity on an indocyanine green fluorescence angiography reflects the blood perfusion within a focused area, the fluorescent light intensity in the remaining in situ parathyroid glands may predict postoperative hypocalcemia risk after total thyroidectomy.

METHODS

Seventy patients underwent intraoperative indocyanine green fluorescence angiography after total thyroidectomy. Any parathyroid glands with a vascular pedicle was left in situ while any parathyroid glands without pedicle or inadvertently removed was autotransplanted. After total thyroidectomy, an intravenous 2.5 mg indocyanine green fluorescence angiography was given and real-time fluorescent images of the thyroid bed were recorded using the SPY imaging system (Novadaq, Ontario, Canada). The fluorescent light intensity of each indocyanine green fluorescence angiography as well as the average and greatest fluorescent light intensity in each patient were calculated. Postoperative hypocalcemia was defined as adjusted calcium <2.00 mmol/L within 24 hours.

RESULTS

The fluorescent light intensity between discolored and normal-looking indocyanine green fluorescence angiographies was similar (P = .479). No patients with a greatest fluorescent light intensity >150% developed postoperative hypocalcemia while 9 (81.8%) patients with a greatest fluorescent light intensity ≤150% did. Similarly, no patients with an average fluorescent light intensity >109% developed PH while 9 (30%) with an average fluorescent light intensity ≤109% did. The greatest fluorescent light intensity was more predictive than day-0 postoperative hypocalcemia (P = .027) and % PTH drop day-0 to 1 (P < .001).

CONCLUSION

Indocyanine green fluorescence angiography is a promising operative adjunct in determining residual parathyroid glands function and predicting postoperative hypocalcemia risk after total thyroidectomy.

Parathyroid Autotransplantation During Thyroid Surgery: A Novel Technique Using a Cell Culture Nutrient Solution

INTRODUCTION

Parathyroid autotransplantation is an easy procedure with a low complication rate. We adopted the transplantation into the sternocleidomastoid muscle, which allows an easier and time-saving surgical procedure using the same surgical incision.

METHODS

In this study, we retrospectively reviewed the records of 396 consecutive patients, who underwent total thyroidectomy for benign thyroid disease. In all cases in which a parathyroid was damaged or inadvertently removed, the gland was transplanted; before the autotransplantation, the parathyroid tissue was put in a cell culture nutrient solution for 5 min, afterward fragmented, and then was transplanted in the sternocleidomastoid muscle. To demonstrate a beneficial effect of the cell nutrient solution step, we compared data of transplanted patients with a control group of cases (n = 190) undergoing a standard immediate autotransplantation.

RESULTS

We divided patients in two main groups: group A (n = 160) including subjects that underwent one or more parathyroid gland autotransplantation using the cell nutrient solution, and group B (n = 236) concerning those who were not transplanted. Among patients, 62 hypocalcemias occurred, 40 in the group A and 22 in the group B (P < 0.001): 91.9 % were transient and 8.1 % (5 patients) definitive, all pertaining to the group B. Among controls (group C), 42 hypocalcemias occurred (P = 0.616 vs. group A and P = 0.002 vs. group B) and 3/42 became definitive (P = 0.096 vs. group A and P = 0.121 vs. group B). All differences concerning pre- and postoperative calcium values were statistically significant (P < 0.001).

CONCLUSIONS

We recommend the routine parathyroid autotransplantation, when a vascular damage is certain or suspected, in order to reduce the rate of permanent hypoparathyroidism, using a cell culture nutrient solution before gland transplantation.

Outcomes of Parathyroid Autotransplantation During Total Thyroidectomy: A Comparison with Age- and Sex-Matched Controls

PURPOSE

To determine the effect of parathyroid autotransplantation (PA) on postoperative hypocalcemia in cases of total thyroidectomy.

MATERIALS AND METHODS

Cases undergoing total thyroidectomy and PA were compared with age and sex-matched controls who had not undergone PA. The postoperative percentage changes (PC) of parathyroid hormone (PTH) and calcium (Ca+2) in the first 12-24 hours (12-24hr→preop), between the 1st-3rd weeks (1-3wk→preop) and at the 6th month (6mo→preop), the rates of hypocalcemia (Ca+2< 8mg/dL) and low PTH level (PTH< 15 pg/mL), permanent hypocalcemia, inadvertent parathyroidectomy in both groups were compared.

RESULTS

The number of patients with PTH12-24hr<15 pg/mL was significantly higher (n:34,(55.7%)) than the number of patients in the control group (n:16(26.2%)), (p=0.001). The rate of decrease in the blood Ca+2 median PC (6mo→preop) was significantly higher in the PA group (4.2%) than the control group (1.1%), (p=0.008). There was no significant difference between the 2 groups in terms of the postoperative frequency of hypocalcemia (p>0.05). In the PA&age≤50 group, the rate of inadvertent parathyroidectomy was higher than that of cases over age 50 (p=0.029).

CONCLUSION

In spite of the presence of an increased postoperative hypocalcemia trend in cases requiring PA during total thyroidectomy, the rates of transient and permanent hypocalcemia were not different to the control cases. But the frequency of cases with low PTH level in cases undergoing PA was higher than that of the control cases. In cases of 50 years of age and under, who had undergone PA, the possibility of inadvertent parathyroidectomy increased.

2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis

BACKGROUND

Thyrotoxicosis has multiple etiologies, manifestations, and potential therapies. Appropriate treatment requires an accurate diagnosis and is influenced by coexisting medical conditions and patient preference. This document describes evidence-based clinical guidelines for the management of thyrotoxicosis that would be useful to generalist and subspecialty physicians and others providing care for patients with this condition.

METHODS

The American Thyroid Association (ATA) previously cosponsored guidelines for the management of thyrotoxicosis that were published in 2011. Considerable new literature has been published since then, and the ATA felt updated evidence-based guidelines were needed. The association assembled a task force of expert clinicians who authored this report. They examined relevant literature using a systematic PubMed search supplemented with additional published materials. An evidence-based medicine approach that incorporated the knowledge and experience of the panel was used to update the 2011 text and recommendations. The strength of the recommendations and the quality of evidence supporting them were rated according to the approach recommended by the Grading of Recommendations, Assessment, Development, and Evaluation Group.

RESULTS

Clinical topics addressed include the initial evaluation and management of thyrotoxicosis; management of Graves' hyperthyroidism using radioactive iodine, antithyroid drugs, or surgery; management of toxic multinodular goiter or toxic adenoma using radioactive iodine or surgery; Graves' disease in children, adolescents, or pregnant patients; subclinical hyperthyroidism; hyperthyroidism in patients with Graves' orbitopathy; and management of other miscellaneous causes of thyrotoxicosis. New paradigms since publication of the 2011 guidelines are presented for the evaluation of the etiology of thyrotoxicosis, the management of Graves' hyperthyroidism with antithyroid drugs, the management of pregnant hyperthyroid patients, and the preparation of patients for thyroid surgery. The sections on less common causes of thyrotoxicosis have been expanded.

CONCLUSIONS

One hundred twenty-four evidence-based recommendations were developed to aid in the care of patients with thyrotoxicosis and to share what the task force believes is current, rational, and optimal medical practice.

Comparison of Bilateral Axillo-Breast Approach Robotic Thyroidectomy with Open Thyroidectomy for Graves' Disease

BACKGROUND

There is an ongoing debate about whether robotic thyroidectomy (RT) is appropriate for Graves' disease. The aim of this study was to compare the safety of bilateral axillo-breast approach (BABA) RT with that of open thyroidectomy (OT) in patients with Graves' disease.

METHODS

From January 2008 to June 2014, 189 (44 BABA RT and 145 OT) patients underwent total thyroidectomy for Graves' disease. Recurrence of Graves' disease, intraoperative blood loss, hospital stay, and complication rates including recurrent laryngeal nerve (RLN) palsy and hypoparathyroidism were analyzed between BABA RT and OT groups, after propensity score matching according to age, gender, body mass index, surgical indication, the extent of operation, excised thyroid weight, and follow-up period.

RESULTS

No patient experienced recurrence of Graves' disease after median follow-up of 35.0 months. Intraoperative blood loss (151.8 ± 165.4 mL vs. 134.5 ± 75.4 mL; p = 0.534) and hospital stay (3.4 ± 0.7 day vs. 3.3 ± 0.7 day; p = 0.564) were not different between BABA RT and OT groups. Complication rates including transient RLN palsy (11.4 vs. 11.4%; p = 1.000), transient hypoparathyroidism (18.2 vs. 20.5%; p = 0.787), permanent RLN palsy (0 vs. 2.3%; p = 0.315), and permanent hypoparathyroidism (2.3 vs. 2.3%; p = 1.000) were also comparable between groups.

CONCLUSIONS

BABA RT for Graves' disease showed comparable surgical completeness and complications to conventional OT. BABA RT can be recommended as an alternative surgical option for patients with Graves' disease who are concerned about cosmesis.

Hypocalcemia after thyroidectomy in patients with a history of bariatric surgery

BACKGROUND

Hypocalcemia is a common complication after total thyroidectomy. Previous bariatric surgery could be a higher factor risk for hypocalcemia due to alterations in calcium absorption and vitamin D deficiency.

OBJECTIVES

To evaluate incidence and factors involved in the risk of hypocalcemia (transient and permanent) and the postoperative outcomes of these patients after total thyroidectomy.

SETTING

University hospital in Paris, France.

METHODS

All patients who had previously undergone obesity surgery (i.e., Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric band) who had a total thyroidectomy from 2006 to 2015 were included. No patient was lost to follow-up. Each patient was matched 1:1 with a patient who had no previous bariatric surgery for age, gender, body mass index, and year of surgery.

RESULTS

Forty-eight patients were identified (43 female; mean age 48.9±9.2 yr). Nineteen patients (40%) had a postoperative hypocalcemia: transient in 14 patients (29.2%) and permanent in 5 patients (10.4%). No significant predictive clinical or biochemical factors were found for hypocalcemia risk, except for the type of bariatric procedure: Bypass surgery had a 2-fold increased risk of hypocalcemia compared to others procedures (60% versus 30%, P = .05). In the matched pair analysis, the risk of hypocalcemia was significantly higher in patients with previous bariatric surgery than in the matched cohort (40% versus 15%, P = .006).

CONCLUSION

Patients with previous bariatric surgery have an increased risk for hypocalcemia after total thyroidectomy, especially after Roux-en-Y gastric bypass. Careful and prolonged follow-up of calcium, vitamin D, and parathyroid hormone levels should be suggested for these patients.

Influence of change in surgical practice for benign thyroid disease on postsurgical outcome-Single-center experience in 1400 patients

PURPOSE

To evaluate the rate of surgical complications during the change from subtotal resection to hemithyroidectomy or thyroidectomy over a period of 17 years.

METHODS

All operations for benign goiter at our hospital were analyzed for the periods 1996-2002 (Group 1) and 2003-2012 (Group 2). The groups were compared for recurrent laryngeal nerve damage, hypocalcemia, and other surgical complications directly postoperatively.

RESULTS

In total, 1462 patients were operated on for goiter between 1996 and 2012. There were 1219 patients who underwent a primary thyroid operation, whereas 50 patients had surgery for recurrence. Postoperative histology revealed thyroid cancer in 193 patients (13.2%). In Group 1, 42.7% of all operated lobes were performed as lobectomies and 57.3% as subtotal resections; in Group 2, 74.4% were performed as lobectomies and 25.6% as subtotal resections. No differences were found for reduced vocal cord function (2.4% vs. 1.9%, p = 0.746) and recurrent laryngeal nerve paralysis in the postoperative laryngoscopy (2.9% vs. 1.8%, p = 0.675). Postoperative hypoparathyroidism was detected in 13.66% in Group 1 and in 19.80% in Group 2 after bilateral resections (p = 0.037). There was no difference in the rate of reoperations for cancer between both groups (43.4% vs. 52.1%, p = 0.182).

CONCLUSION

Surgical practice changed from subtotal to lobectomies for benign goiter over a period of 17 years without change in laryngeal nerve damage but with increasing rates of postoperative hypocalcemia.

DOES PRE-OPERATIVE VITAMIN D DEFICIENCY PREDICT POSTOPERATIVE HYPOCALCEMIA AFTER THYROIDECTOMY?

OBJECTIVE

Postoperative hypocalcemia is frequent after total thyroidectomy. The role of pre-operative vitamin D levels in the pathogenesis of this condition has not been studied under the most current guidelines for evaluation of the role of vitamin D in calcium homeostasis. We hypothesized that patients who are vitamin D deficient (VDD) pre-operatively are more likely to suffer from postoperative hypocalcemia, thereby requiring prolonged hospitalization.

METHODS

A retrospective chart review of patients undergoing total thyroidectomy at the University of New Mexico Hospital between 2005 and 2014 was performed. Patients who underwent intentional parathyroidectomy were excluded. The study included 30 patients who had a 25-hydroxyvitamin D levels obtained within 12 months before surgery.

RESULTS

Twelve patients who were VDD (25-hydroxyvitamin D ≤20 ng/mL) were compared to 18 patients who did not have VDD (non-VDD; 25-hydroxyvitamin D >20 ng/mL). The mean nadir postoperative ionized calcium concentration was lower in the VDD group (0.99 ± 0.10 vs. 1.06 ± 0.06 mmol/L, P = .04) (reference range = 1.15-1.27 mmol/L), as was the postoperative concentration of phosphorus (3.48 ± 0.60 vs. 4.17 ± 0.84 mg/dL, P = .03). VDD patients had a longer length of stay (4.3 ± 4.4 vs. 1.7 ± 1.5 days, P = .03). Three patients in the VDD group required intravenous calcium for treatment of symptomatic hypocalcemia, but none of the non-VDD patients required this intervention (P = .054).

CONCLUSION

Pre-operative vitamin D deficiency is associated with an increased risk of postoperative hypocalcemia and a prolonged length of stay in patients undergoing total thyroidectomy. Vitamin D replacement before thyroidectomy may improve postsurgical outcomes in VDD patients.

ABBREVIATIONS

BMI = body mass index non-VDD = non-vitamin D deficient PTH = parathyroid hormone VDD = vitamin D deficient.

Predictors and risk factors of hypoparathyroidism after total thyroidectomy

BACKGROUND

The aim of this study was to evaluate the risk factors for hypoparathyroidism after total thyroidectomy and to determine whether early postoperative serum levels of calcium and phosphorus could be used to predict its development.

MATERIALS AND METHODS

The study group consisted of 1030 patients who had undergone total thyroidectomy at our institution between March 2008 and July 2014. The clinicopathologic characteristics, indications for the operation, and surgical details of normocalcemic and hypocalcemic patients were compared, and variations in serum calcium and phosphorus levels were measured every day after the operation.

RESULTS

Of the 1030 patients, 291 (28.2%) were found to have transient hypocalcemia and 27 (2.6%) had permanent hypocalcemia. On univariate analysis, younger age (P = 0.001), female gender (P < 0.001), longer operative time (P = 0.009), extent of central neck dissection (CND) (P = 0.003), and malignancy (P = 0.005) were found to be significantly associated with transient hypocalcemia. On multivariate analysis, female gender (P = 0.001), extent of CND (P = 0.017), and the identification of parathyroid gland (PTG) tissue in permanent pathologic sections were significant factors. In addition, the occurrence of postoperative hypocalcemia was correlated with relative changes in serum calcium and phosphorus levels. Patients whose serum calcium levels decreased over 20% on postoperative day 2 were more likely to develop hypoparathyroidism, with 92% specificity.

CONCLUSION

Female gender (P = 0.001), extent of CND (P = 0.014), and PTG in permanent pathologic sections (P = 0.035) were found to be significant factors affecting the development of hypocalcemia. Despite some study limitations, we suggest that the relative changes in the serum levels of calcium (20%) and of phosphorus (40%) on the second postoperative day may be reliable predictors of post-thyroidectomy hypoparathyroidism.

The effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism

AIM

To investigate the effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism.

MATERIAL AND METHODS

This controlled, randomized, prospective cohort was carried out on 40 patients who admitted for surgery due to hyperthyroidism. Cases were randomly assigned to receive either preoperative treatment with Lugol solution (Group 1) or no preoperative treatment with Lugol solution (Group 2). Group 3 (n = 10) consisted of healthy adults with no known history and signs of hyperthyroidism. Blood flow through the thyroid arteries of patients was measured by color flow Doppler ultrasonography. Free T3, free T4, TSH, thyroid volume and the resistance index of the four main thyroid arteries were measured in all patients.

RESULTS

There was not a significant difference between gender, preoperative serum thyroid hormone levels, or thyroid gland volumes between groups 1 and 2. The mean blood flow of the patients in Group 1 was significantly lower than values in Group 2. When age, gender, thyroid hormone, TSH, thyroid volume, blood flow, and Lugol solution treatment were included as independent variables, Lugol solution treatment (OR, 7.40; 95% CI, 1.02-58.46; p = 0.001) was found to be the only significant independent determinant of intraoperative blood loss. Lugol solution treatment resulted in a 7.40-fold decrease in the rate of intraoperative blood loss.

CONCLUSION

Preoperative Lugol solution treatment was found to be a significant independent determinant of intraoperative blood loss. Moreover, preoperative Lugol solution treatment decreased the rate of blood flow, and intraoperative blood loss during thyroidectomy.

Analysis of the incidence and factors predictive of inadvertent parathyroidectomy during thyroid surgery

BACKGROUND

Inadvertent (or incidental) parathyroidectomy can occur during thyroidectomy. However, the factors associated with inadvertent parathyroidectomy remain unclear. This study aimed to report the rate of inadvertent parathyroidectomy during thyroidectomy and associated risk factors.

METHODS

Variables including fine needle aspiration cytology findings, age, sex, thyroid weight, concurrent neck dissection, extent of thyroidectomy, and the presence of cancer and parathyroid tissue within the specimen were recorded for 266 patients. The incidence of post-operative hypocalcaemia was also recorded. Univariate and multivariate analysis were performed to identify factors associated with inadvertent parathyroidectomy.

RESULTS

The inadvertent parathyroidectomy rate was 16 per cent. Univariate analysis revealed that cancer and concurrent neck dissection predicted inadvertent parathyroidectomy. On multivariate analysis, only concurrent neck dissection remained an independent predictor of inadvertent parathyroidectomy: it was associated with a fourfold increase in inadvertent parathyroidectomy.

CONCLUSION

The inadvertent parathyroidectomy rate was 16 per cent and concurrent neck dissection was identified as an independent predictor of inadvertent parathyroidectomy.

Association between Magnesium Disorders and Hypocalcemia following Thyroidectomy

OBJECTIVE

To identify factors associated with postoperative hypocalcemia after thyroid surgery and to understand the relationship among hypocalcemia, length of hospitalization, and costs of care.

STUDY DESIGN

Retrospective database analysis.

METHODS

Discharge data from the Nationwide Inpatient Sample for 620,744 patients who underwent thyroid surgery from 2001 to 2010 were analyzed through cross-tabulations and multivariate regression modeling. Hypocalcemia, length of stay, and costs were examined as dependent variables. Secondary independent variables included magnesium and phosphate metabolism disorders, vitamin D deficiency, menopause, sex, extent of surgery, malignancy, and surgeon volume.

RESULTS

Hypocalcemia was reported in 6% of patients and was significantly more common for the following variables: women, age <65 years, patients from the Northeast, total thyroidectomy ± neck dissection patients, low-volume surgical care, malignancy, recurrent laryngeal nerve injury, and patients with disorders of magnesium or phosphate metabolism (P < .001). Magnesium and phosphate disorders were present in <1% of patients. Magnesium disorders were significantly more likely for patients with hypocalcemia (7%; P < .001), and hypocalcemia was present in 52% of patients with magnesium disorders (P < .001). On multiple logistic regression analysis, the odds of hypocalcemia were greatest for patients with magnesium disorders (odds ratio, 12.71; 95% confidence interval, 8.59-18.82). This relationship was not attenuated by high-volume surgical care. Hypocalcemia and magnesium disorders were both associated with increased length of stay and costs, with a greater effect for magnesium disorders than for hypocalcemia (P < .001).

CONCLUSIONS

Disorders of magnesium metabolism are an independent risk factor for postthyroidectomy hypocalcemia and are associated with significantly increased costs and length of stay.

Factors affecting postoperative hypocalcemia after thyroid surgery: Importance of incidental parathyroidectomy

OBJECTIVE

The present study evaluated effects of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism on occurrence of postoperative persistent or transient hypocalcemia.

METHODS

Patients who underwent thyroidectomy at İstanbul Medeniyet University between 2013 and 2015 were included in the study. Patient information, postoperative serum calcium levels, and pathology reports were investigated retrospectively. Group 1 was made up of patients who were found to have hypocalcemia (calcium ≤8.5 mg/dL) according to postoperative serum level and normocalcemic patients were placed in Group 2. Groups were compared statistically in terms of rate of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism.

RESULTS

Mean age was 49.8±12.8 years (range: 20-88). A total of 417 patients were included in the study, 74 (17.7%) were male and 343 (82.3%) were female. Group 1 consisted of 205 (49.2%) patients who had hypocalcemia according to postoperative serum level, and remaining 212 (50.8%) patients were placed in Group 2. In Group 1, 38 (18.5%) patients had incidental parathyroidectomy, and with only 18 (8.5%) patients in Group 2, a statistically significant relationship was found between incidental parathyroidectomy and hypocalcemia (p=0.003). There was no statistically significant difference in terms of presence of thyroiditis or hyperthyroidism between groups. There was statistically significant decrease in postoperative hypocalcemia rate in patients with lobectomy compared to patients with bilateral total thyroidectomy or central neck dissection (p<0.01).

CONCLUSION

Risk of postoperative hypocalcemia may be reduced with lobectomy for selected patients. In addition, delicate dissection during thyroidectomy is important in order to protect parathyroid glands and prevent hypocalcemia.

Parathyroid gland angiography with indocyanine green fluorescence to predict parathyroid function after thyroid surgery

BACKGROUND

Postoperative hypoparathyroidism remains the most common complication following thyroidectomy. The aim of this pilot study was to evaluate the use of intraoperative parathyroid gland angiography in predicting normal parathyroid gland function after thyroid surgery.

METHODS

Angiography with the fluorescent dye indocyanine green (ICG) was performed in patients undergoing total thyroidectomy, to visualize vascularization of identified parathyroid glands.

RESULTS

Some 36 patients underwent ICG angiography during thyroidectomy. All patients received standard calcium and vitamin D supplementation. At least one well vascularized parathyroid gland was demonstrated by ICG angiography in 30 patients. All 30 patients had parathyroid hormone (PTH) levels in the normal range on postoperative day (POD) 1 and 10, and only one patient exhibited asymptomatic hypocalcaemia on POD 1. Mean(s.d.) PTH and calcium levels in these patients were 3·3(1·4) pmol/l and 2·27(0·10) mmol/l respectively on POD 1, and 4·0(1.6) pmol/l and 2·32(0·08) mmol/l on POD 10. Two of the six patients in whom no well vascularized parathyroid gland could be demonstrated developed transient hypoparathyroidism. None of the 36 patients presented symptomatic hypocalcaemia, and none received treatment for hypoparathyroidism.

CONCLUSION

PTH levels on POD 1 were normal in all patients who had at least one well vascularized parathyroid gland demonstrated during surgery by ICG angiography, and none required treatment for hypoparathyroidism.

Can Total Thyroidectomy Be Safely Performed by Residents?: A Comparative Retrospective Multicenter Study

This retrospective comparative multicenter study aims to analyze the impact on patient outcomes of total thyroidectomy (TT) performed by resident surgeons (RS) with close supervision and assistance of attending surgeons (AS).All patients who underwent TT between 2009 and 2013 in 10 Units of endocrine surgery (8 in Italy, 1 in France, and 1 in UK) were evaluated. Demographic data, preoperative diagnosis, extension of goiter, type of surgical access, surgical approach, operative time, use and duration of drain, length of hospitalization, histology, and postoperative complications were recorded. Patients were divided into 3 groups: A, when treated by an AS assisted by an RS; B and C, when treated by a junior and a senior RS, respectively, assisted by an AS.The 8908 patients (mean age 51.1 ± 13.6 years), with 6602 (74.1%) females were enrolled. Group A counted 7092 (79.6%) patients, Group B 261 (2.9%) and Group C 1555 (17.5%). Operative time was significantly greater (P < 0.001) in B (101.3 ± 43.0 min) vs A (71.8 ± 27.6 min) and C (81.2 ± 29.9 min). Duration of drain was significantly lower (P < 0.001) in A (47.4 ± 13.2 h) vs C (56.4 ± 16.5 h), and in B (42.8 ± 14.9 h) vs A and C. Length of hospitalization was significantly longer (P < 0.001) in C (3.8 ± 1.8 days) vs B (2.4 ± 1.0 days) and A (2.6 ± 1.5 days). No mortality occurred. Overall postoperative morbidity was 22.3%: it was significantly higher in B vs A (29.5% vs 22.3%; odds ratio [OR] 1.46, 95% confidence interval [CI] 1.11-1.92, P = 0.006) and C (21.3%; OR 1.55, 95% CI 1.15-2.07, P = 0.003). No differences were found for recurrent laryngeal nerve palsy, hypoparathyroidism, hemorrhage, and wound infection. The adjusted ORs in multivariate analysis showed that overall morbidity remained significantly associated with Group B vs A (OR 1.48, 95% CI 1.12-1.96, P = 0.005) and vs C (OR 1.60, 95% CI 1.19-2.17, P = 0.002), while no difference was observed in Group A vs B + C.TT can be safely performed by residents correctly supervised. Innovative gradual training in dedicated high-volume hospitals should be proposed in order to allow adequate autonomy for the RS and safeguard patient outcome.

Outcome of hypocalcaemia after thyroidectomy treated only in symptomatic patients

BACKGROUND

Calcium supplementation has been proposed after bilateral thyroid surgery, either to all patients or to those with biochemical hypocalcaemia. It has also been suggested that supplementation aids parathyroid recovery and prevents permanent hypoparathyroidism. This single-centre study investigated the feasibility of a restrictive management of post-thyroidectomy hypocalcaemia.

METHODS

Serum calcium was checked before surgery, on postoperative day 1 (POD) 1, at a follow-up visit 6-8 weeks after surgery and after a minimum of 12 months in all patients. Regardless of serum calcium levels, patients with symptoms of hypocalcaemia were prescribed oral calcium supplementation (0·5-1·0 g twice daily) and asymptomatic patients were not. Asymptomatic patients were informed about hypocalcaemic symptoms and instructed to contact the surgical ward should symptoms appear.

RESULTS

Some 640 patients underwent bilateral thyroid surgery without previous or intentional simultaneous parathyroidectomy. A subnormal serum calcium level (below 2·15 mmol/l) was observed in 412 patients (64·4 per cent) on POD 1. By comparison, only 63 patients (9·8 per cent) experienced symptoms of hypocalcaemia in the postoperative period, all but one with a corresponding biochemical hypocalcaemia on POD 1. Calcium levels in all patients with asymptomatic postoperative hypocalcaemia recovered to normal without supplementation. Serum calcium was also normalized during follow-up in all symptomatic patients, except 22 (3·4 per cent) who became permanently hypoparathyroid. No patient without early hypocalcaemic symptoms developed permanent hypoparathyroidism.

CONCLUSION

The proposed restrictive management of postoperative hypocalcaemia after bilateral thyroid surgery avoids unnecessary supplementation for most patients.

Impact of preoperative Vitamin D3 administration on postoperative hypocalcaemia in patients undergoing total thyroidectomy (HypoCalViD): study protocol for a randomized controlled trial

Background

Total thyroidectomy is increasingly used as a surgical approach for many thyroid conditions. Subsequently, postoperative hypocalcaemia is observed with increasing frequency, often resulting in prolonged hospital stay, increased use of resources, reduced quality of life and delayed return to work. The administration of vitamin D is essential in the therapy of postoperative hypocalcaemia; calcitriol is most commonly used. What has not been examined so far is whether and how routine preoperative vitamin D prophylaxis using calcitriol can help to prevent postoperative hypocalcaemia. This study evaluates routine preoperative calcitriol prophylaxis for all patients who are to undergo a total thyroidectomy, compared with the current standard of post-treatment, i.e., selective vitamin D treatment for patients with postoperative hypocalcaemia.

Methods/design

This clinical observational (minimal interventional clinical trial) trial is a multicentre, prospective, randomized superiority trial with an adaptive design. Datasets will be pseudonymized for analysis. Patients will be randomly allocated (1:1) to the intervention and the control groups. The only intervention is 0.5 μg calcitriol orally twice a day for 3 days prior to surgery. For the primary endpoint measure (number of patients with hypocalcaemia), hypocalcaemia is defined as serum calcium of less than 2.1 mmol/l on any day during the postoperative course; this measure will be analyzed using a Chi-square test comparing the two groups. Secondary endpoint measures, such as number of days to discharge, quality of life, and economic parameters will also be analyzed.

Discussion

By virtue of the direct comparison of clinically and economically relevant endpoints, the efficacy as well as efficiency of preoperative calcitriol prophylaxis of hypocalcaemia will be clarified. These results should be available 24 months after the first patient has been enrolled. The results will be used to inform a revised practice parameter guideline of whether or not to recommend preoperative calcitriol for all patients in whom total thyroidectomy is planned.

Trial registration

Deutsches Register Klinischer Studien, DRKS00005615 (Feb.12.2016).

Visualizing fewer parathyroid glands may be associated with lower hypoparathyroidism following total thyroidectomy

BACKGROUND

It remains uncertain whether the number of parathyroid glands (PGs) seen during extra-capsular dissection impacts short- and long-term hypoparathyroidism. Our study aimed to address this by analyzing patients who underwent total thyroidectomy for benign disease.

METHODS

Consecutive patients undergoing total thyroidectomy were analyzed. The extra-capsular dissection technique was performed throughout the study period. The number of PGs identified, auto-transplanted and found on excised specimen was recorded prospectively. The number of PGs in situ was equaled to four minus the number of PGs auto-transplanted and PGs found on specimen. Temporary hypoparathyroidism was defined as serum adjusted calcium <2.00 mol/L 24 h after surgery and/or need for oral supplements while protracted hypoparathyroidism meant subnormal PTH (<1.2 pmol/L) at 4-6 weeks and/or need for >6-week oral supplements. Permanent hypoparathyroidism was defined as need for oral supplements for ≥1 year.

RESULTS

Five-hundred and sixty-nine patients were eligible for analysis. After adjusting for other significant parameters, greater number of PGs identified was an independent risk factor for temporary (p < 0.001) and protracted hypoparathyroidism (p = 0.007). Mean recovery time from protracted hypoparathyroidism for identifying ≤three PGs was significantly shorter than identifying all four PGs (2.8 vs. 7.8 months, p < 0.001). Chance of having all four PGs in situ decreased with greater number of PGs identified (p < 0.001).

CONCLUSIONS

When the extra-capsular technique was adopted during total thyroidectomy, identifying fewer PGs in their orthotopic positions not only lowered risk of temporary and protracted hypoparathyroidism but also shortened recovery from protracted hypoparathyroidism.

IS THERE A RELATIONSHIP BETWEEN VITAMIN D STATUS AND HYPOCALCEMIA AFTER TOTAL THYROIDECTOMY?

Context

Vitamin D plays a crucial role in calcium metabolism through parathormone-dependent process. Deficiency of this important nutrient may be associated with hypocalcemia after thyroidectomy.

Objective

To evaluate the role of vitamin D in predicting hypocalcemia following total thyroidectomy.

Subjects and Methods

One hundred and fifty patients who underwent total thyroidectomy for benign or malignant thyroid disease were included in this prospective study. The association between preoperative vitamin D status and the development of hypocalcemia were investigated.

Results

Biochemical and symptomatic hypocalcemia were found in 28 (18.7%) and 22 (14.7%) patients, respectively. Preoperative vit D level was found significantly lower in patients with biochemical (p = 0.006) and clinical (p < 0.001) hypocalcemia in comparison to normocalcemic patients. The patients who had <10 ng/mL vit D level (severe deficiency) developed significantly more biochemical and clinical hypocalcemia than the patients with serum vit D level higher than 10 ng/mL (p = 0.030 and p < 0.001, respectively).

Conclusions

Although postthyroidectomy hypocalcemia is multifactorial, vit D deficiency, particularly severe form, is significantly associated with the development of biochemical and clinical hypocalcemia. Vit D supplementation can prevent this unwanted complication in such patients.

Incidental Parathyroidectomy during Total Thyroidectomy: Risk Factors and Consequences

Objective. To evaluate the incidence of accidental parathyroidectomy in our series of total thyroidectomies, to investigate its clinical and biochemical consequences, and to identify potential risk factors. Methods. Patients who underwent total thyroidectomy between January 2006 and December 2015 were retrospectively analyzed. Pathology reports were reviewed to identify those cases who had an incidental parathyroidectomy and these were compared to patients with no parathyroidectomy, in terms of clinical (age, sex, and symptoms of hypocalcemia), pathological (thyroid specimen weight, Hashimoto thyroiditis, and malignancy), and biochemical (serum calcium and phosphate levels) factors. Results. 281 patients underwent total thyroidectomy during the study period. Incidental parathyroidectomy was noticed in 24.9% of cases, with 44.3% of parathyroid glands found in an intrathyroidal location. Evidence of postoperative biochemical hypocalcemia was noticed in 28.6% of patients with parathyroidectomy, compared with 13.3% in the no-parathyroidectomy group (p = 0.003). Symptomatic hypocalcemia was observed in 5.7% and 3.8%, respectively (p = 0.49). Age, sex, thyroid specimen weight, Hashimoto thyroiditis, and malignancy did not differ significantly between the two groups. Conclusions. Our study found an association of incidental parathyroidectomy with transient postoperative biochemical hypocalcemia, but not with clinically symptomatic disease. Age, sex, thyroid gland weight, Hashimoto thyroiditis, and malignancy were not identified as risk factors.

One-hour PTH after thyroidectomy predicts symptomatic hypocalcemia

BACKGROUND

A major morbidity after total thyroidectomy is hypocalcemia. Although many clinical factors and laboratory studies have been correlated with both biochemical and symptomatic hypocalcemia, the ideal use and timing of these tests remain unclear. We hypothesize 1-h (PACU) parathyroid hormone (PTH) will identify patients at risk for symptomatic hypocalcemia.

METHODS

This prospective study evaluated 196 patients undergoing total thyroidectomy. Serum calcium and PTH levels were measured 1 h after surgery and on postoperative day 1 (POD1). Performance of a central compartment lymph node dissection, parathyroid autotransplantation, indication for procedure, pathology, and presence of parathyroid tissue in the pathology specimen were recorded.

RESULTS

Of 196 patients, nine (4.6%) developed symptomatic hypocalcemia. Thirty four (17.3%) had a 1-h PACU PTH ≤10 pg/dL, whereas 31 (15.8%) had a POD1 PTH of ≤10. Five (56%) of the nine symptomatic patients underwent central compartment lymph node dissection, four (44%) had parathyroid autotransplantation, and four (44%) had a PACU PTH ≤10. PACU and POD1 PTH levels were correlated (R(2) = 0.682). Multivariate regression identified central compartment dissection, autotransplantation, and PACU or POD1 PTH correlated with symptomatic hypocalcemia. PACU PTH, POD1 PTH, PACU Ca, malignant final pathology, and age ≤45 y correlated with biochemical hypocalcemia.

CONCLUSIONS

A 1-h postoperative PACU PTH is equivalent to POD1 PTH in predicting the development of symptomatic hypocalcemia. Biochemical hypocalcemia was not predictive of symptoms in the immediate postoperative period. Lymph node dissection and parathyroid autotransplantation correlated with symptomatic hypocalcemia and improve the sensitivity of biochemical screening alone.

[Consensus statement for accreditation of multidisciplinary thyroid cancer units]

Thyroid cancer is the leading endocrine system tumor. Great advances have recently been made in understanding of the origin of these tumors and the molecular biology that makes them grow and proliferate, which have been associated to improvements in diagnostic procedures and increased availability of effective local and systemic treatments. All of the above makes thyroid cancer a paradigm of how different specialties should work together to achieve the greatest benefit for the patients. Coordination of all the procedures and patient flows should continue throughout diagnosis, treatment, and follow-up, and is essential for further optimization of resources and time. This manuscript was prepared at the request of the Working Group on Thyroid Cancer of the Spanish Society of Endocrinology and Nutrition, and is aimed to provide a consensus document on the definition, composition, requirements, structure, and operation of a multidisciplinary team for the comprehensive care of patients with thyroid cancer. For this purpose, we have included contributions by several professionals from different specialties with experience in thyroid cancer treatment at centers where multidisciplinary teams have been working for years, with the aim of developing a practical consensus applicable in clinical practice.

European Society of Endocrinology Clinical Guideline: Treatment of chronic hypoparathyroidism in adults

Hypoparathyroidism (HypoPT) is a rare (orphan) endocrine disease with low calcium and inappropriately low (insufficient) circulating parathyroid hormone levels, most often in adults secondary to thyroid surgery. Standard treatment is activated vitamin D analogues and calcium supplementation and not replacement of the lacking hormone, as in other hormonal deficiency states. The purpose of this guideline is to provide clinicians with guidance on the treatment and monitoring of chronic HypoPT in adults who do not have end-stage renal disease. We intend to draft a practical guideline, focusing on operationalized recommendations deemed to be useful in the daily management of patients. This guideline was developed and solely sponsored by The European Society of Endocrinology, supported by CBO (Dutch Institute for Health Care Improvement) and based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) principles as a methodological base. The clinical question on which the systematic literature search was based and for which available evidence was synthesized was: what is the best treatment for adult patients with chronic HypoPT? This systematic search found 1100 articles, which was reduced to 312 based on title and abstract. The working group assessed these for eligibility in more detail, and 32 full-text articles were assessed. For the final recommendations, other literature was also taken into account. Little evidence is available on how best to treat HypoPT. Data on quality of life and the risk of complications have just started to emerge, and clinical trials on how to optimize therapy are essentially non-existent. Most studies are of limited sample size, hampering firm conclusions. No studies are available relating target calcium levels with clinically relevant endpoints. Hence it is not possible to formulate recommendations based on strict evidence. This guideline is therefore mainly based on how patients are managed in clinical practice, as reported in small case series and based on the experiences of the authors.

Pediatric thyroidectomy in a high volume thyroid surgery center: Risk factors for postoperative hypocalcemia

INTRODUCTION

Hypocalcemia is a common complication following thyroid surgery. We seek to report on our experience in pediatric thyroidectomy in a high volume thyroid surgery center and accurately assess the incidence of postoperative hypocalcemia.

MATERIALS AND METHODS

A retrospective review of patients aged 18 and younger who underwent thyroid surgery between 1992 and 2013. The primary endpoints were the occurrence of postoperative hypocalcemia as by defined as a nadir calcium <8.0mg/dL and being discharged on oral calcium supplementation, need for intravenous calcium and the occurrence of permanent hypoparathyroidism.

RESULTS

171 patients who underwent 186 thyroid operations were analyzed. The average age was 15.4years with 82.3% female. The most common indications for surgery were nodular disease (74.7%) and hyperthyroidism (12.4%). 24 patients (12.9%) experienced postoperative hypocalcemia with 13 (7.0%) requiring intravenous calcium infusion. One patient (0.9%) experienced permanent hypoparathyroidism. Risk factors for postoperative hypocalcemia included total thyroidectomy (OR 7.39, p<0.01), central and bilateral lateral neck dissection (OR 22.26, p=0.01), Graves' disease (OR 3.99, p=0.02), and malignancy (OR 2.96, p=0.03).

CONCLUSIONS

Pediatric patients who undergo total thyroidectomy for underlying malignancy or Graves' disease and those who have more extensive nodal dissections are at increased risk of developing this postoperative hypocalcemia. These patients may benefit from more vigilant preoperative preparation and postoperative calcium and vitamin D supplementation.

Is Preoperative Vitamin D Deficiency a Risk Factor for Postoperative Symptomatic Hypocalcemia in Thyroid Cancer Patients Undergoing Total Thyroidectomy Plus Central Compartment Neck Dissection?

BACKGROUND

Although some studies have reported that preoperative vitamin D deficiency (VDD) is a risk factor for hypocalcemia after total thyroidectomy (TT) in patients with nontoxic multinodular goiter or Graves' disease, the association between VDD and postoperative hypocalcemia in thyroid cancer patients undergoing TT plus central compartment neck dissection (CCND) remains unclear. This study evaluated whether preoperative VDD was associated with postoperative symptomatic hypocalcemia.

MATERIALS AND METHODS

Data were collected prospectively between September 2012 and May 2013. A total of 267 consecutive thyroid cancer patients who underwent TT with CCND were analyzed. Patients were divided into two groups--VDD or non-VDD--by preoperative vitamin D level of <10 or ≥10 ng/mL. Symptomatic hypocalcemia was defined as serum calcium <8.2 mg/dL and symptoms or signs of hypocalcemia. The rates of postoperative symptomatic hypocalcemia and clinicopathological features were compared between the two patient groups.

RESULTS

The rate of postoperative symptomatic hypocalcemia was higher in the VDD group than in the non-VDD group (43.8% vs. 30.4%, p=0.043). By logistic regression analysis, predictive factors for postoperative symptomatic hypocalcemia included a preoperative vitamin D level of <10 ng/mL (p=0.007; odds ratio=3.00). In patients who had postoperative intact parathyroid hormone (iPTH) levels <15 pg/mL, symptomatic hypocalcemia was more common in the VDD group than in the non-VDD group (77.5% vs. 53.2%, p=0.008). The findings show that a preoperative vitamin D threshold level of >20 ng/mL reduced the risk of symptomatic hypocalcemia by 72% when compared with patients with VDD (p=0.003).

CONCLUSION

VDD is significantly associated with postoperative symptomatic hypocalcemia in thyroid cancer patients undergoing TT plus CCND. VDD was predictive for symptomatic hypocalcemia when patients had postoperative serum iPTH levels <15 pg/mL. Thus, preoperative supplementation with oral vitamin D should be considered to minimize postoperative symptomatic hypocalcemia.

Hypoparathyroidism after total thyroidectomy: incidence and resolution

BACKGROUND

Parathyroid hormone (PTH) levels are often measured after thyroid surgery and are used to detect patients at risk for postoperative hypoparathyroidism. However, there is a lack of consensus in the literature about how to define the recovery of parathyroid gland function and when to classify hypoparathyroidism as permanent. The goals of this study were to determine the incidence of low postoperative PTH in total thyroidectomy patients and to monitor their time course to recovery of parathyroid gland function.

METHODS

We identified 1054 consecutive patients who underwent a total or completion thyroidectomy from January, 2006-December, 2013. Low PTH was defined as a PTH measurement <10 pg/mL immediately after surgery. Patients were considered to be permanently hypoparathyroid if they had not recovered within 1 y. Recovery of parathyroid gland function was defined as PTH ≥10 pg/mL and no need for therapeutic calcium or activated vitamin D (calcitriol) supplementation to prevent hypocalcemic symptoms.

RESULTS

Of 1054 total thyroidectomy patients, 189 (18%) had a postoperative PTH <10 pg/mL. Of those 189 patients, 132 (70%) showed resolution within 2 mo of surgery. Notably, 9 (5%) resolved between 6 and 12 mo. At 1 y, 20 (1.9%) were considered to have permanent hypoparathyroidism. Surprisingly, 50% of those patients had recovery of PTH levels yet still required supplementation to avoid symptoms.

CONCLUSIONS

Most patients with a low postoperative PTH recover function quickly, but it can take up to 1 y for full resolution. Hypoparathyroidism needs to be defined not only by PTH levels but also by medication requirements.