Clinical aspects of early and late hypocalcaemia afterthyroid surgery

Serial Estimation of Serum Calcium and Ionic Calcium Level for Early Detection of Hypocalcemia After Total/Completion Thyroidectomy

Hypocalcemia is an important and common complication following thyroid surgery. The development of postoperative hypocalcemia is likely to be multifactorial in nature. Patients with acute hypocalcemia may present with numbness of the distal extremities, circumoral paresthesia, and/or carpopedal spasm, laryngospasm, seizure and arrhythmias. In most cases, post-thyroidectomy hypocalcemia is temporary, but small percentage (0-12%) are permanent. The present study was a 1-year prospective interventional study conducted at tertiary care center, Jaipur, India. Total 42 patients who underwent thyroidectomy were included in study. Evaluation of Serum and Ionic Calcium Level done Preoperatively and Postoperative at 6, 12, 24 and 48 h and patients who develops hypocalcemia symptoms were recorded and data were analyzed. In our study hypocalcemia was seen in 13 (31%) out of 42 subjects. Ionic calcium in 'All patients' gradually decreased from pre operative 1.28 ± 0.04 mmol/l to 1.14 ± 0.08 mmol/l by 24 h. Highest incidence of hypocalcemia was seen in patients who had Total thyroidectomy + neck dissection (83.3%) compared to other type of thyroid surgery. we concluded that post thyroidectomy transient hypocalcemia is a frequent complication. Serial monitoring of calcium levels preoperatively and postoperatively combined with careful monitoring of signs and symptoms of hypocalcemia is an efficient and cost-effective tool to detect early post thyroidectomy hypocalcemia.

Near-infrared fluorescent imaging techniques for the detection and preservation of parathyroid glands during endocrine surgery

Objectives

In over 30% of all thyroid surgeries, complications arise from transient and definitive hypoparathyroidism, underscoring the need for real-time identification and preservation of parathyroid glands (PGs). Here, we evaluate the promising intraoperative optical technologies available for the identification, preservation, and functional assessment of PGs to enhance endocrine surgery.

Methods

We performed a review of the literature to identify published studies on fluorescence imaging in thyroid and parathyroid surgery.

Results

Fluorescence imaging is a well-demonstrated approach for both in vivo and in vitro localization of specific cells or tissues, and is gaining popularity as a technique to detect PGs during endocrine surgery. Autofluorescence (AF) imaging and indocyanine green (ICG) angiography are two emerging optical techniques to improve outcomes in thyroid and parathyroid surgeries. Near-infrared-guided technology has significantly contributed to the localization of PGs, through the detection of glandular AF. Perfusion through the PGs can be visualized with ICG, which can also reveal the blood supply after dissection.

Conclusions

Near infrared AF and ICG angiography, providing a valuable spatial and anatomical information, can decrease the incidence of complications in thyroid surgery.

How Long Does It Take to Regain Normocalcaemia in the Event of Postsurgical Hypoparathyroidism? A Detailed Time Course Analysis

Background: Postsurgical hypoparathyroidism (PH) is the most common side effect of bilateral thyroid resections. Data regarding the time course of recovery from PH are currently unavailable. Therefore, a detailed analysis of the time course of PH recovery and conditions associated with rapid recovery was conducted. Methods: This is a retrospective analysis of prospectively documented data. Patients with biochemical signs of PH or need for calcium supplementation were followed-up for 12 months. Logistic regression analyses were used to identify covariates of early as opposed to late recovery from PH. Results: There were 1097 thyroid resections performed from 06/2015 to 07/2016 with n = 143 PH. Median recovery time was 8 weeks and six patients (1.1% of total thyroid resections) required calcium supplementation > 12 months. Recovery of PH within 4 and 12 weeks was characterized by high PTH levels on the first postoperative day (4 weeks: OR 1.13, 95% CI 1.06−1.20; 12 weeks: OR 1.08, 95%CI 1.01−1.16). Visualization of all PTGs emerged as an independent predictor of recovery within 12 months (OR 2.32, 95% CI 1.01−4.93) and 24 weeks (OR 2.69, 95% CI 1.08−6.69). Conclusion: In the setting of specialized high-volume endocrine surgery, permanent PH is rare. However, every second patient will require more than 2 months of continued medical surveillance. Early recovery was associated with only moderately decreased postsurgical PTH-levels. Successful late recovery appeared to be associated with the number of parathyroid glands visualized during surgery.

Role of perioperative parathormone hormone level assay after total thyroidectomy as a predictor of transient and permanent hypocalcemia: Prospective study

BACKGROUND

The researchers are trying to evaluate the measurement of: Intact parathyroid hormone (iPTH) and serum total calcium (sCa) levels for predicting hypocalcemia after total thyroidectomy (TT).

METHODS

The sample of this single center prospective study consists of (100) patients, where (77) females and (23) males with an age range between (28) and (65) (the mean level is, 48.17 ± 6.54). These selected patients underwent total thyroidectomy (TT) in the general surgery department, Benha university hospital from the period of June 2019 to February 2020. Levels of sCa and iPTH were measured aat several times preoperatively, 10 min, 48 h, 3, 6, 9 months, and 1 year after being after gone TT.

RESULTS

Among the entire study sample, 23 patients (23%) developed transient hypoparathyroidism and hypocalcemia (˂8.5 mg/dl), none of them developed permanent hypoparathyroidism and hypocalcemia. The cut-off point of PTH has been 10 min after TT was at 23 pg/mL as it was the best compromise between sensitivity and specificity for predicting hypocalcaemia. It has been found that Patients who have a PTH greater than 23 pg/mL can be discharged safely after 24 h. Patients who have PTH of less than 23 pg/mL were observed for an additional 24 h, and the study found that timely treatment initiation is recommended. A PTH ˂ 10 pg/mL measured at 48 h after surgery had a sensitivity, specificity as well as an accuracy of 100%, for predicting hypocalcemia after TT. The accuracy of a single PTH concentration at 48 h was useful for predicting hypocalcemia [Area under receiver-operator characteristic curve (AUC) 1; confidence interval (CI), 95%, 0.85-0.94].

CONCLUSION

Patients with iPTH ˂ 10 pg/mL, and sCa levels ˂ 7.4 mg/dL are at higher risk of developing hypoparathyroidism and hypocalcemia after TT.

Etiology and Diagnosis of Permanent Hypoparathyroidism after Total Thyroidectomy

Postoperative parathyroid failure is the commonest adverse effect of total thyroidectomy, which is a widely used surgical procedure to treat both benign and malignant thyroid disorders. The present review focuses on the scientific gap and lack of data regarding the time period elapsed between the immediate postoperative period, when hypocalcemia is usually detected by the surgeon, and permanent hypoparathyroidism often seen by an endocrinologist months or years later. Parathyroid failure after thyroidectomy results from a combination of trauma, devascularization, inadvertent resection, and/or autotransplantation, all resulting in an early drop of iPTH (intact parathyroid hormone) requiring replacement therapy with calcium and calcitriol. There is very little or no role for other factors such as vitamin D deficiency, calcitonin, or magnesium. Recovery of the parathyroid function is a dynamic process evolving over months and cannot be predicted on the basis of early serum calcium and iPTH measurements; it depends on the number of parathyroid glands remaining in situ (PGRIS)—not autotransplanted nor inadvertently excised—and on early administration of full-dose replacement therapy to avoid hypocalcemia during the first days/weeks after thyroidectomy.

EARLIER PREDICTION OF HYPOCALCEMIA BY POSTOPERATIVE SECOND HOUR PARATHYROID HORMONE LEVEL AFTER TOTAL THYROIDECTOMY

Context

Thyroidectomy is becoming an ambulatory surgical procedure. By predicting hypocalcemia,duration of hospital stay might decline. We tried to determine whether measuring parathormone two hours after total thyroidectomy predicts hypocalcemia.

Objective

We aimed to design a protocol for early prediction of hypocalcemia by defining PTH measurement time and cut-off value of our center.

Design

One hundred and six patients undergoing total thyroidectomy between November 2017 and October 2018 were prospectively studied.

Methods

Pregnant women, patients with renal failure, parathyroid disease, previous neck operation and thyroid malignancy requiring neck dissection were excluded from the study. Parathormone (PTH) and calcium measurement was done preoperatively and in the postoperative second hour.

Results

Group 1 consisted of 75 normocalcemic patients while group 2 had 31 hypocalcemic patients. Mean age was 45±13.1 (age range: 18-76). Female/male ratio was 82/24. While with a 8.36 pg/mL postoperative second hour PTH, hypocalcemia can be predicted with a 51.5% sensitivity and 90.7% specificity while with a PTH decline of 40.8% hypocalcemia can be diagnosed with a 83.9% sensitivity and 52% specificity.

Conclusion

Postoperative second hour PTH and PTH percentage decline can predict postoperative hypocalcemia in total thyroidectomies. Preoperative Dual-energy X-ray absorptiometry (DXA) was not found useful in hypocalcemia prediction.

A rare case of spondyloarthropathy: Iatrogenic hypoparathyroidism

Hypoparathyroidism is an endocrinopathy that can develop idiopathically, as well as due to reasons associated with genetics, autoimmunity, surgery and radiotherapy. It usually presents with neuromuscular signs and symptoms, including enthesopathy caused by calcification of the ligament and enthesis sites, soft tissue calcification, hypertension, cataract and extrapyramidal findings due to basal ganglia calcification. Hypoparathyroidism-associated spondyloarthropathy (SpA) is a rarely seen clinical entity. Hypoparathyroidism-associated SpA differs from other inflammatory SpAs in that the results for human leukocyte antigen B27 and inflammatory markers are negative and bone density is normal. The symptoms are relieved by calcium and vitamin D, rather than anti-inflammatory drugs. Due to this difference in treatment modalities, the diagnosis of this type of SpA is important. This article presents the case report of a 52-year-old female patient with iatrogenic hypoparathyroidism accompanied by asymptomatic hypocalcemia and SpA clinic.

Impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy

OBJECTIVES

To determine the impact of incidental parathyroidectomy and mediastinal-recurrent cellular and lymph-node dissection on parathyroid function after total thyroidectomy.

MATERIAL AND METHODS

A single-center retrospective study was conducted for a 5-year period in a university hospital center, including 605 patients undergoing total thyroidectomy, 52 of whom had mediastinal-recurrent cellular and lymph-node dissection.

ENDPOINTS

The main endpoint was intraoperative number of parathyroid glands as predictor of parathyroid hormone (PTH) level and postoperative hypocalcemia. The secondary endpoint was the correlation between associated mediastinal-recurrent cellular and lymph-node dissection and incidental parathyroidectomy and its impact on PTH level and calcemia in the immediate postoperative period and at 1 month.

RESULTS

161 patients (26.61%) showed hypocalcemia in the immediate postoperative period and 12 (1.98%) at 1 month. Mediastinal-recurrent cellular and lymph-node dissection increased incidental parathyroidectomy risk 4.6-fold. Mediastinal-recurrent cellular and lymph-node dissection was associated with a statistically "suggestive" decrease in day-1 calcemia (P=0.03), and no significant decrease at 1 month (P=0.52). Incidental parathyroidectomy (6.7% of cases with parathyroidectomy versus 1.3% without) did not significantly increase the rate of early hypocalcemia (P=0.28), but was associated with a "suggestive" worsening at 1 month (P=0.02).

CONCLUSION

Hypocalcemia after total thyroidectomy is a complex, probably multifactorial issue. Systematic parathyroid gland identification is not recommended due to the increased risk of gland lesion, mainly by devascularization. Incidental parathyroidectomy may induce hypocalcemia at 1 month postoperatively (statistically "suggestive" association).

Postoperative hypocalcemia: analysis of factors influencing early hypocalcemia development following thyroid surgery

BACKGROUND

Early Hypocalcemia is the most frequent complication after thyroid surgery. Several studies have tried to identify factors (patient caracteristics or surgical technique variations) affecting hypocalcemia following thyroid surgery. This studiy evaluates the role of several factors in postoperative hypocalcemia development.

METHODS

A retrospective study conducted on 2108 patients that underwent thyroid surgery in a single center (1669 women and 439 men). Postoperative early hypocalcemia was defined as serum calcium levels lower than 8,0 mg/dl measured 24 h after surgery. Following factors were evaluated in the study: sex, age, glandular hyperfunction, preoperative diagnosis, preoperative serum calcium levels, preoperative serum PTH levels, type of surgery performed (total thyroidectomy vs. lobectomy); minimally invasive video assisted thyroidectomy (MIVAT); number of parathyroid preserved in situ, postoperative serum calcium levels, changes in perioperative calcium levels (difference between preoperative values ​​and postoperative calcium levels), presence of carcinoma in the surgical specimen, presence of thyroiditis based on histopatology reports.

RESULTS

Among evaluated factors only gender and surgical procedure revealed to be significantly correlated to early hypocalcemia development. In fact female patients experienced postoperative hypocalcemia in 42% (701/1669) of cases, which was signicantly higher than the 21.4% (94/439) identified in men. We also noticed a greater hypocalcemia incidence in patient undergoing total thyroidectomy (38.8%) than in patient undergoing lobectomy group (13.8%). Early hypocalcemia development didn't appear to be related to preoperative serum calcium levels but it showed a statistically significant correlation with perioperative serum calcium level drop.

CONCLUSION

This findings suggest that sex (female gender is a strong risk factor),surgical procedure and perioperative changes in serum calcium are the only factors (among all variables examined) that influence early hypocalcemia development.

Experience of thyroid surgery at tertiary referral centers in Jazan Hospitals, Saudi Arabia

Background

Benign multinodular goiter (BMNG) is a common disease of the thyroid gland with palpable thyroid nodules that may be detected in 0.8%–1.5% of men and 5.3%–6.4% of women. Three major complications could be detected after total thyroidectomy: hemorrhage, recurrent laryngeal paralysis, and hypoparathyroidism.

Aims

The aim of this study was to review and assess the experience of total thyroidectomy in patients with BMNG at tertiary referral centers in Jazan Hospitals, Saudi Arabia.

Methods

A retrospective study was conducted on 320 patients diagnosed with BMNG and subjected to primary total thyroidectomy. Operative mortality and major complications [bleeding, recurrent laryngeal nerve (RLN) injury, and hypoparathyroidism] were recorded.

Results

Postoperative hemorrhage was reported in four patients (1.25%). Bilateral RLN injuries occurred in two patients (0.6%), whereas unilateral RLN injuries occurred in nine patients (2.8%). Permanent hypoparathyroidism was diagnosed in three patients (0.9%), while transient hypoparathyroidism occurred in eight patients (2.5%) and improved after 4 months.

Conclusions

Total thyroidectomy represents today the treatment of choice for BMNG. Proper preoperative preparations, meticulous surgical dissection with careful follow-up of patients will improve the surgical results and reduce postoperative complications.

How many parathyroid glands can be identified during thyroidectomy?: Evidence-based data for medical experts

Background

The purpose of this study is to provide guidance for medical experts regarding malpractice claims on permanent hypoparathyroidism by analyzing the number of parathyroid glands (PGs) identified during thyroidectomy and the clinical outcome.

Methods

Parathyroid findings were documented in a standardized protocol for 357 patients undergoing thyroidectomy and treated by a single specialized surgeon. The resected thyroid was routinely dissected for accidentally removed PGs with consecutive autotransplantation and the pathological report also described unintentionally resected PGs. Follow-up was performed for 6 months.

Results

The mean number of identified PGs was 2.28. No PGs were found in 20 (5.6%), one in 56 (15.7%), two in 126 (35.3%), three in 114 (31.9%), and four in 41 (11.5%) cases. One patient (0.28%) had manifest permanent hypoparathyroidism, while ten patients (2.8%) had latent permanent hypoparathyroidism (hypocalcemia and normoparathyroidism). The risk factors identified for postoperative hypoparathyroidism were an increasing number of visualized PGs, autotransplantation, central neck dissection, and PGs in the histopathological work-up. For permanent hypoparathyroidism, PGs in the histology examination and neck dissection were significant, but the number of identified PGs was not.

Conclusion

Even an experienced surgeon is not always able to find all four PGs during thyroidectomy and occasionally identifies none. Rather than focusing on identifying a minimum number of PGs, it is more important not to miss them in risky positions. A documented awareness of PGs, i. e., knowledge of variable parathyroid positions and their saving, is a prerequisite for surgical quality and to protect surgeons from claims.

Short and long-term impact of parathyroid autotransplantation on parathyroid function after total thyroidectomy

The most common complication of total thyroidectomy is parathyroid insufficiency. Acute, transient, post-operative hypoparathyroidism increases length of hospitalization, morbidity and cost associated with total thyroidectomy. While permanent hypoparathyroidism poses a significant medical burden with lifetime medication, regular follow up and considerable disease burden related to chronic renal failure and other sequelae. Parathyroid autotransplantation has been demonstrated to result in biochemically functional grafts, leading to the procedures' common use during total thyroidectomy. The clearest indications for parathyroid auto transplantation are inadvertently removed or devascularized parathyroid glands. Some centers utilize routine autotransplantation to reduce the risk of permanent hypoparathyroidism. Novel fluorescence techniques to aid in parathyroid detection during thyroid surgery are under evaluation. This review aims to define the role and impact of parathyroid autotransplantation undertaken during total thyroidectomy.

PARATHYROID FUNCTION AFTER TOTAL THYROIDECTOMY: A RANDOMIZED CLINICAL TRIAL CONCERNING THE INFLUENCE OF THE SURGICAL TECHNIQUE

OBJECTIVE

Thyroidectomy impairs parathyroid function, even if it does not necessarily lead to postoperative clinical hypocalcemia. This study was prospective and evaluated the parathyroid hormone (PTH) function in nonclinically symptomatic patients after total thyroidectomy performed by two different techniques.

METHODS

Prospective randomized clinical trial including 269 patients undergoing classic or harmonic scalpel total thyroidectomy. Pre-operatively and at 48 hours, biochemical analysis was performed. Simultaneously, a sodium bicarbonate test (SBT) was performed.

RESULTS

Calcium and PTH were altered for both groups ( P<.001). During SBT at 3 minutes after infusion, PTH rose and reached its maximum for both groups ( P<.001) and then decreased at 5 minutes ( P<.001 and P = .004) and at 10 minutes ( P = .006 and P = .043) before returning to baseline levels. At 5 and 10 minutes of the SBT, some differences were observed between the groups. The difference in clinically obvious parathyroid dysfunction between groups was not significant, but there was a difference in the peak PTH levels after bicarbonate stimulation. Similarly, total secretion during the test, as well as total secretion for the first 10 minutes, was practically the same for the two groups. Additionally, partial subclinical postoperative hypoparathyroidism was clearly more common in the harmonic scalpel thyroidectomy group ( P<.001).

CONCLUSION

SBT demonstrated more impairment in the harmonic scalpel group, as parathyroid function was altered after thyroidectomy.

ABBREVIATIONS

HSTT = harmonic scalpel total thyroidectomy PTH = parathyroid hormone SBIT = sodium bicarbonate infusion test.

The Impact of Postoperative Percent Change of Parathormone Level From Baseline Value on the Rate of Hypocalcemia After Total Thyroidectomy

Background

The purpose of this study was to investigate the impact of the percent change of postoperative parathormone (PoPTH) level from baseline value (ΔPTH) on the rate of hypocalcemia after total thyroidectomy.

Methods

Assays of serum PTH and calcium (Ca) were performed preoperatively and at 24 hours postoperatively in 222 consecutive patients who underwent total thyroidectomy. Postoperative hypocalcemia was defined as serum calcium level corrected for albumin concentration (cCa) &lt;8.5 mg/dL. Patients with postoperative hypocalcemia were classified as group 1 (n = 100) and those with normal Ca levels as group 2 (n = 122). The PoPTH levels and ΔPTH were compared between the 2 groups. Receiver operating characteristic analysis was performed to determine the cutoff values for PoPTH and ΔPTH.

Results

The mean PoPTH level was significantly lower in group 1 compared with group 2 (18.6 ± 15.3 versus 32.3 ± 15.6 pg/mL, respectively; P &lt; 0.0001). PoPTH values were within the normal range in 54% of the patients with hypocalcemia and 35% of those with symptomatic hypocalcemia. PoPTH &lt;28 pg/mL or ΔPTH &gt;45 were significantly associated with increased risk of post-thyroidectomy hypocalcemia (P = 0.0001). A ΔPTH &gt;70%, PoPTH ≤15.5 pg/mL, and postoperative serum cCa concentrations&lt;8.0 mg/dL significantly predicted symptomatic hypocalcemia (P = 0.009, P = 0.006, and P = 0.0001, respectively). The sensitivities of ΔPTH, PoPTH level, and postoperative serum cCa concentration to predict symptomatic hypocalcemia were 67%, 64%, and 100%, respectively.

Conclusion

Although PTH decline significantly correlates with symptomatic hypocalcemia, a considerable number of patients may experience hypocalcemic symptoms despite normal PoPTH levels. Analysis of serum Ca concentrations at 24 hours postoperatively help to achieve a more precise prediction of patients who bear a high risk for developing hypocalcemic symptoms.

Parathyroid hormone and serum calcium levels measurements as predictors of postoperative hypocalcemia in total thyroidectomy

Background

The rules of quantitative measures such as parathyroid hormone (PTH) levels in the first hours following total thyroidectomy have since been validated repeatedly. Such measures play an integral rule in identifying patients at significant risk for hypocalcaemia and have allowed for earlier supplementation of these patients with calcium with or without vitamin D.

Methods

A retrospective analysis was conducted of 40 consecutive patients with well differentiated thyroid cancer (WDTC) who underwent total thyroidectomy without central neck dissection (CND) as an initial surgery and no comorbidity at King Abdulaziz Medical City (National Guard hospital), between July 2011 and July 2012. A blood testing protocol was applied for all patients that measured serum calcium PTH at 6 hours postoperatively.

Results

Following total thyroidectomy, women were found to experience transient hypocalcaemia in 12.5% of cases (4/32), whereas no men cases encountered this postoperative complication (0/8). However, most probably due to small sample size, this difference was not statistically significant. PTH level was significantly associated with post thyroidectomy hypocalcaemia (43.7±39.3 versus 13.40±24.9 ng/L), P=0.014. Only negligible differences in the length of hospital stay were observed with and without post-thyroidectomy hypocalcaemia.

Conclusions

Using post-thyroidectomy PTH levels to predict hypocalcaemia has been confirmed in the current study. So, the use of PTH levels allows for early risk stratification of our patients and we feel this has resulted in better patient satisfaction.

The Utility of Serum PTH Assessment 24 Hours after Total Thyroidectomy

BACKGROUND: Hypocalcemia is the most frequent complication following total thyroidectomy. This prospective study examines the predictive value of parathyroid hormone (PTH) levels measured 24 hours after surgery.

MATERIAL AND METHODS: A total of 1006 consecutive patients (mean age, 54.8 years; female/male ratio, 4/1) underwent total thyroidectomy for benign or malignant thyroid from January 1995 to November 2003. Serum calcium, phosphorus, and PTH were measured preoperatively and at 24 hours after surgery. All patients underwent preoperative examination to assess cord motility.

RESULTS: A total of 253 (25.1%) patients presented with hypocalcemia demonstrated by clinical and laboratory findings. In 101 cases the hypocalcemic syndrome manifested after 24 to 36 hours whereas in 5 of 101 cases, symptom onset was between 48 and 72 hours. Serum calcium levels lower than 7.5 mg/dL were recorded in all the 101 cases. In 239 of 253 cases serum calcium returned to normal values within 7 days following surgery. PTH at 24 hours was below normal levels in 49 of the 101 patients but was within normal limits in 52 cases. The incidence of hypocalcemia was higher in patients undergoing surgery for malignant thyroid ( P < 0.05).

CONCLUSIONS: We do not consider PTH levels at 24 hours postoperatively as predictive of hypocalcemia.

Prophylactic neck dissection for low-risk differentiated thyroid cancers: Risk-benefit analysis

BACKGROUND

The benefit of neck dissection is the subject of debate in differentiated thyroid cancer (DTC). We analyze the risk-benefit of neck dissection for low-risk DTC without detectable lymph nodes.

METHODS

We conducted a retrospective study from 1983 to 2003; which included 295 patients without detectable lymph nodes who were treated by thyroidectomy with (C+) or without (C-) neck dissection. All patients had iodine131 therapy. We compared the frequency of remission, disease progression, and permanent complications between groups.

RESULTS

Two hundred twelve patients comprised the C+ group, and 83 patients the C- group. Respectively for C+ versus C-, remission rates were 92% versus 89.2% (p = .40), and progressive disease observed was 3.3% versus 7.2% (p = .10). Permanent hypoparathyroidism occurred in 15.1% in C+ versus 3.6% in C- (p = .006).

CONCLUSION

The risk-benefit analysis of neck dissection in patients with low-risk DTC shows no benefit in terms of complete remission or occurrence of progression. However, risk of complications seems to be higher in patients with neck dissection. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1091-1096, 2016.

Identifying Parathyroid Glands With Carbon Nanoparticle Suspension Does Not Help Protect Parathyroid Function in Thyroid Surgery: A Prospective, Randomized Control Clinical Study

Objective We aim to evaluate the technique of identifying parathyroid glands with carbon nanoparticle suspension (CNPS) in thyroid surgeries from the perspectives of degrees of declining intact parathyroid hormone (iPTH), operation time, and time of postoperative stay. Methods A total of 156 patients who underwent thyroid surgeries in General Surgical Department of Xiangya Hospital between May 2012 and May 2015 were involved in the study. A total of 78 patients were injected with CNPS during the surgery (CNPS group); the other 78 patients received normal saline (control group). Cases were classified into 3 surgical approaches: conventional partial thyroidectomy, conventional total thyroidectomy, and endoscopic partial thyroidectomy. Degrees of declining iPTH were tested to determine the severity of parathyroid injury. Operation time and postoperative hospital stay time were recorded. A P value of less than .05 was considered statistically significant. Results For levels of declining iPTH, there was no statistically significant (ss) difference in conventional thyroid surgery. In endoscopic partial thyroidectomy, it was 23.37 ± 16.20 versus 11.94 ± 11.23 pg/mL (P = .02, ss). The operation time of conventional total thyroidectomy was 210.10 ± 83.75 versus 164.84 ± 69.22 minutes (P = .03, ss), while it was 193.04 ± 75.53 versus 127.67 ± 60.06 minutes (P = .007, ss) in endoscopic thyroidectomy. Conclusions CNPS is not beneficial for protecting the function of parathyroid gland in thyroid surgery from the perspective of declining iPTH. Applying CNPS in conventional total thyroidectomy and endoscopic partial thyroidectomy will also lead to significantly prolonged operation time.

Factors predicting post-thyroidectomy hypoparathyroidism recovery

BACKGROUND

Hypoparathyroidism is the most common complication after thyroidectomy and the main reason for frequent outpatient visits; however, there is a poor understanding of its outcomes and no clear follow-up strategies are available. We aimed to predict post-thyroidectomy hypoparathyroidism outcomes and identify relevant factors.

METHODS

A multicenter, standardized prospective study was conducted. The parathyroid hormone level (PTH) was measured preoperatively and at the first hour after surgery, then at each outpatient follow-up visit after 1 week, 3 weeks, and 1 month, and then every 2 months, until it either reached normal values or up to 6 months. Cox proportional hazard modeling was used to determine the factors that affect PTH recovery. A Weibull distribution model was used to predict time to recovery. Both models were evaluated by goodness of fit.

RESULTS

A total of 186 patients were enrolled in the study; 53 (28.5 %) developed hypoparathyroidism, 47 of them (88.6 %) females. Their mean age was 41.2 years, and 11.4 % were diabetic. Of these women, 33 (62.3 %) recovered within 1 month, 10 (18.9 %) recovered after 1 month but within 6 months, 7 (13.2 %) did not recover within 6 months, and 3 (5.6 %) missed follow-up. Factors that are found to affect and predict the speed of recovery were the preoperative PTH level, perioperative percent drop in PTH level, diabetes mellitus, and gender.

CONCLUSIONS

This study provides potentially useful information for early prediction of PTH recovery, and it highlights the factors that affect the course of hypoparathyroidism recovery, which in turn should be reflected in better patient management, improved patient satisfaction, and overall cost-effectiveness.

Molecular Analysis by Gene Expression of Mitochondrial ATPase Subunits in Papillary Thyroid Cancer: Is ATP5E Transcript a Possible Early Tumor Marker?

BACKGROUND

Cancer development involves an "injury" to the respiratory machinery (Warburg effect) due to decreased or impaired mitochondrial function. This circumstance results in a down regulation of some of the ATPase subunits of the malignant tissue. The objective of this work was to assess and compare the relative expression of mRNA of mitochondrial ATPase subunits between samples of thyroid cancer and benign nodules.

MATERIAL AND METHODS

Samples from 31 patients who had an operation for PTC at the General Hospital of Mexico were snap-frozen and stored at -70°C. Thirty-five patients who had an operation for benign tumors were also included in the study. mRNA expression levels of alpha, beta, gamma, and epsilon subunits of F1 and "c12" of subunit Fo were determined by real-time RT-PCR (by duplicate), in order to determine if abnormal expression of these genes could partially explain the Warburg effect in papillary thyroid cancer (PTC).

RESULTS

ATP5E transcript alteration (down-expression) was highly associated to PTC diagnosis OR=11.76 (95% confidence interval, 1.245-237.98; p=0.04).

CONCLUSIONS

Relative down-expression of ATP5E transcript was highly associated with PTC diagnosis. This transcript alteration may be used as a tumoral marker in papillary thyroid cancer.

Clinical Pathway for Thyroidectomy

Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia.

Defining the syndromes of parathyroid failure after total thyroidectomy

Acute and chronic parathyroid insufficiency syndromes are the most common complication after total thyroidectomy. Permanent hypoparathyroidism imposes an important medical burden on patient lifestyle due to the need for lifetime medication, regular visits and significant long-term costs. Its true prevalence has been underestimated due to lack of clear definitions, inadequate follow-up and conflicts of interest when reporting individual patient series. The aim of this review is to propose precise definitions for the different syndromes associated to parathyroid failure based on the follow-up and management of patients developing hypocalcemia (<8 mg/dL at 24 hours) after first-time total thyroidectomy for cancer or goiter at our unit. Short and long-term post-thyroidectomy parathyroid failure presents as three different metabolic syndromes: (I) postoperative hypocalcemia is defined as a s-Ca <8 mg/dL (<2 mmol/L) within 24 hours after surgery requiring calcium/vit D replacement therapy at the time of hospital discharge; (II) protracted hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement at 4-6 weeks; and (III) permanent hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement 1 year after total thyroidectomy. Each of these syndromes has its own pattern of recovery and should be approached with different therapeutic strategies.

The Cost of Prolonged Hospitalization due to Postthyroidectomy Hypocalcemia: A Case-Control Study

The aim of this study is to evaluate the additional costs associated with calcium monitoring and treatment as well as evaluate the incidence and predictors of postthyroidectomy hypocalcemia. Methods. This case-control study involved thyroidectomy and completion thyroidectomy patients operated on between January 2012 and August 2013. Cases were defined as requiring calcitriol supplementation, and controls did not require supplementation. Patient (age, sex), nodule (cytology, pathology), surgical data (neck dissection, parathyroid identification, and reimplantation), and hospital stay (days hospitalized in total and after drain removal) were compared. Comparisons were made using t-tests and chi-square tests with an alpha of 0.05. The estimated cost associated with the extended stay was then compared with the cost of supplementation. Results. A total of 191 patients were evaluated (61 cases and 130 controls). Predictors of hypocalcemia include female age, neck dissection, and parathyroid reimplantation. Hypocalcemic patients were hospitalized for a longer period of time after drain removal (2.5 versus 0.8 days, P<0.001), and hospitalization costs after neck drain removal were higher in this group as well (8,367.32$ versus 2,534.32$, P<0.001). Conclusion. Postoperative hypocalcemia incurs significant additional health care costs at both the local and health care system levels.

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

BACKGROUND

Hypocalcaemia is common after thyroidectomy. Accurate prediction and appropriate management may help reduce morbidity and hospital stay. The aim of this study was to perform a systematic literature review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane Library databases was undertaken, and the quality of manuscripts assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Some 115 observational studies were included. The median (i.q.r.) incidence of transient and permanent hypocalcaemia was 27 (19-38) and 1 (0-3) per cent respectively. Independent predictors of transient hypocalcaemia included levels of preoperative calcium, perioperative parathyroid hormone (PTH), preoperative 25-hydroxyvitamin D and postoperative magnesium. Clinical predictors included surgery for recurrent goitre and reoperation for bleeding. A calcium level lower than 1·88 mmol/l at 24 h after surgery, identification of fewer than two parathyroid glands (PTGs) at surgery, reoperation for bleeding, Graves' disease and heavier thyroid specimens were identified as independent predictors of permanent hypocalcaemia in multivariable analysis. Factors associated with transient hypocalcaemia in meta-analyses were inadvertent PTG excision (odds ratio (OR) 1·90, 95 per cent confidence interval 1·31 to 2·74), PTG autotransplantation (OR 2·03, 1·44 to 2·86), Graves' disease (OR 1·75, 1·34 to 2·28) and female sex (OR 2·28, 1·53 to 3·40).

CONCLUSION

Perioperative PTH, preoperative vitamin D and postoperative changes in calcium are biochemical predictors of post-thyroidectomy hypocalcaemia. Clinical predictors include female sex, Graves' disease, need for parathyroid autotransplantation and inadvertent excision of PTGs.

Pseudohypoparathyroidism type II in a woman with a history of thyroid surgery

We herein describe the case of a woman with pseudohypoparathyroidism (PHP) type II. She had a history of subtotal thyroidectomy against Graves' disease without levothyroxine supplementation and presented with stiffness, numbness and muscle cramps. Her surgical history suggested the possibility of secondary hypoparathyroidism; however, the serum intact parathyroid hormone level and results of a Ellsworth-Howard test led to the diagnosis of PHP type II. In the present case, making the differential diagnosis was challenging because two distinct disorders, such as PHP and secondary hypoparathyroidism, may exist simultaneously. This case demonstrates the need to consider the possibility of PHP type II in patients exhibiting hypocalcemia.

Intact parathyroid hormone measurement at 24 hours after thyroid surgery as predictor of parathyroid function at long term

BACKGROUND

There is no consensus about the usefulness of postoperative intact parathyroid hormone (iPTH) determination to predict permanent hypoparathyroidism (pHPP). We evaluated the value of calcium (Ca2+) and iPTH concentration at 24 hours after total thyroidectomy (TT) for predicting pHPP.

METHODS

Ca2+ and iPTH levels from 70 consecutive patients who underwent TT were measured at 24 hours and 6 months after TT.

RESULTS

Five patients (7.1%) developed pHPP. An iPTH concentration ≤5.8 pg/mL at 24 hours after TT identified patients at risk for pHPP (sensitivity, 100%; specificity, 81.5%), but it was not accurate enough to predict its development (positive predictive value, 30%). Conversely, an iPTH level >5.8 pg/mL predicted normal parathyroid function at 6 months (negative predictive value, 100%). Compared with iPTH, a postoperative Ca2+ level ≤1.95 mmol/L was 60% sensitive and 78.5% specific to predict pHPP.

CONCLUSIONS

An iPTH concentration >5.8 pg/mL on the first postoperative day rules out pHPP with much better diagnostic accuracy than Ca2+. Postoperative iPTH could be helpful in identifying patients at risk for developing pHPP.

Is thyroidectomy in patients with Hashimoto thyroiditis more risky?

BACKGROUND

Hashimoto thyroiditis (HT) is an organ-specific autoimmune disease characterized by the production of antibodies such as antithyroperoxidase, which leads to the destruction of the thyroid gland and a decrease in normal thyroid function. Thyroidectomy is performed when the patient presents with symptoms or potential neoplastic degeneration occurs; however, surgery can be difficult because of the dense inflammatory process around the thyroid gland. We hypothesized that patients with HT may have a higher rate of complications after thyroid surgery.

METHODS

We identified 1791 consecutive patients who underwent thyroidectomy from May 1994 to December 2009. Patients with HT were compared with those without HT with regard to outcomes with analysis of variance and chi-square test (SPSS, Inc).

RESULTS

Patients with HT were significantly younger and more likely to be female. There was no significant difference between the two groups in the rate of malignancy. However, patients undergoing thyroidectomy with HT had a significantly higher postoperative complication rate. Specifically, the rates of overall, transient, and permanent complications were all increased in HT patients.

CONCLUSION

Patients with HT had a higher rate of complications after thyroidectomy compared with those without HT. Therefore, careful consideration must be taken before pursuing operative treatment in patients with HT including providing adequate informed consent regarding the increased risks of surgery.

Applicability of imediate, late or serial intact parathyroid hormone measurement following total thyroidectomy

Hypocalcemia is the most common complication after total thyroidectomy. Intact parathyroid hormone (i-PTH) testing is a proven effective method to detect patients at risk for postoperative symptomatic hypocalcemia. However, there is still uncertainty as to the timing of i-PTH testing in a clinical setting.

Objective

This study looked into the correlation between serum i-PTH levels measured at different times after total thyroidectomy and the risk of symptomatic hypocalcemia.

Methods

This retrospective case series studied a group of 110 consecutive for hypocalcemia and intact parathyroid hormone (PTHi) levels four and twelve hours following total thyroidectomy. Statistical analysis was used to evaluate the performance of isolated and serial i-PTH measurements to determine the likelihood of symptomatic hypocalcemia.

Results

I-PTH is highly sensitive (90.3%-96.8%) and specific (77.2%-87.3%) for symptomatic hypocalcemia. There was no significant difference in the sensitivity levels of the tests done four and twelve hours after surgery or in a serial fashion. However, the 12-hour i-PTH level was more specific (p < 0.0007).

Conclusion

Single i-PTH testing done 12 hours after total thyroidectomy may be used as a screening test to detect patients at risk for symptomatic hypocalcemia.

Parathyroid hormone: an early predictor of symptomatic hypocalcemia after total thyroidectomy

OBJECTIVE: The purpose of this study was to evaluate if the measurement of peri-operative parathyroid hormone (PTH) is able to identify patients with increased risk of developing symptoms of hypocalcemia. SUBJECTS AND METHODS: Forty patients who underwent total thyroidectomy were studied prospectively. Ionized serum calcium and PTH were measured after induction of anesthesia, one hour (PTH1) and one day after surgery (PTH24). Patients were evaluated for symptoms of hypocalcemia and treated with calcium and vitamin D supplementation as necessary. RESULTS: Symptomatic hypocalcemia developed in 16 patients. Symptomatic patients had significant lower PTH1 and greater drops in PTH levels. The selection of 12.1 ng/L as PTH1 level cutoff level divided patients with and without symptoms with 93.7% sensitivity and 91.6% specificity. The selection of 73.5% as the cutoff value for PTH decrease resulted in 91.6% sensitivity and 87.5% specificity. CONCLUSION: PTH1 levels and the drop in PTH levels are reliable predictors of developing symptomatic hypocalcemia after total thyroidectomy.

Female Gender as a Risk Factor for Transient Post-Thyroidectomy Hypocalcemia

Objectives. Transient post-thyroidectomy hypocalcemia is a common complication following thyroid surgery. Studies have identified risk factors and possible ways to help predict post-thyroidectomy hypocalcemia with the intent of ultimately limiting its incidence. This study evaluates the role of patient gender as a potential risk factor.

Study Design. A retrospective case series with chart review of 270 consecutive total thyroidectomy patients was conducted.

Setting. Jewish General Hospital, a McGill University–affiliated hospital in Montreal, Canada.

Subjects and Methods. 219 women and 51 men were included. Postoperative hypocalcemia was defined as any 1 of the following: total serum calcium 1.90 mmol/L or less, or signs and symptoms of hypocalcemia. The following were evaluated as potential confounding factors in the study: age, menopause, preoperative calcium, parathyroid hormone, magnesium and phosphate levels, presence of carcinoma in the surgical specimen, number of parathyroid glands preserved in situ, thyroid gland volume, and nodule size.

Results. Female patients experienced transient postoperative hypocalcemia in 24.7% (54/219) of cases, which was significantly greater than the 11.8% (6/51) incidence detected in men ( P < .05). This represents a female/male relative risk ratio of 2.1 (confidence interval, 1.0-4.6). There was no significant difference in rates of hypocalcemia between premenopausal and postmenopausal women (22.7% vs 26.6%).

Conclusion. These findings suggest that being female is likely a risk factor for transient post-thyroidectomy hypocalcemia. Although this association is statistically significant, its magnitude and clinical relevance are uncertain and may be trivial. Additional research is needed to ascertain the physiologic mechanisms underlying this gender difference.

An algorithm informed by the parathyroid hormone level reduces hypocalcemic complications of thyroidectomy

BACKGROUND

Measurement of the parathyroid hormone (PTH) level following total thyroidectomy (TTx) may allow prediction of postoperative hypocalcemia. We present an algorithmic method of managing hypocalcemia pre-emptively, based on the PTH level 1 h after operation.

MATERIALS AND METHODS

We examined 423 consecutive patients undergoing TTx at a single institution. A subset of patients were managed using an algorithm involving routine postoperative oral calcium administration and the early addition of oral calcitriol in patients with a low 1-h postoperative PTH level. Algorithm patients were compared to a concurrent, conventionally managed group. Outcomes measured included serum calcium levels, symptoms of hypocalcemia, postoperative complications, and receipt of intravenous (i.v.) calcium.

RESULTS

The algorithm was applied in 135 patients, and 288 patients were managed conventionally. Critically low calcium levels (total calcium <7.5 mg/dl [1.88 mmol/l] or ionized calcium <0.94 mmol/l) were less common in algorithm patients (10.6% vs. 25.3%; p < 0.005). Much of this difference was attributable to the protective impact of the algorithm on patients undergoing TTx for cancer, 30% of whom developed critically low calcium levels when managed conventionally. Among patients requiring i.v. calcium, algorithm patients received fewer doses (1.29 vs. 1.86; p < 0.05). Low 1-h PTH levels were found in 21% (28/133) of algorithm patients, but these did not correlate with low calcium levels, suggesting that the algorithm compensated adequately for temporary hypoparathyroidism. No patients developed hypercalcemia.

CONCLUSIONS

An algorithmic approach incorporating early postoperative PTH levels and routine administration of oral calcium reduces the risk of severe hypocalcemia after total thyroidectomy.

Loupe Magnification Reduces Postoperative Hypocalcemia after Total Thyroidectomy

We aimed to evaluate the impact of loupe magnification (LM) on incidental parathyroid gland removal (from pathology reports), hypocalcemia, and recurrent laryngeal nerve (RLN) injury after total thyroidectomy and answer the question of whether this tool should be always recommended for patient's safety. Between January 2005 and December 2008, 126 patients underwent total thyroidectomy with routine use of 2.5 X galilean loupes; their charts were compared with data on 118 patients operated on between January 1997 and December 2000 without LM (two different equally skilled surgical teams operating in the two periods). LM decreased the rate of inadvertent parathyroid glands removal (3.8 vs 7.8% of total parathyroid glands; P = 0.01), as well as of biochemical (20.6 vs 33.9%; P = 0.028) and clinical (12.7 vs 33%; P = 0.0003) hypocalcemia after thyroidectomy. All cases (16 of 16) of symptomatic hypocalcaemia in the LM group proved to be associated with parathyroidectomy vs 76.9 per cent (30 of 39) without LM ( P = 0.046). A trend toward decreased RLN injury rate, although statistically insignificant, was reported, being unilateral transient, unilateral permanent, and bilateral transient palsy rates 6.8, 2.5, and 1.7 per cent, respectively, without LM vs 4.8, 2.4, and 0.8 per cent, respectively, with LM ( P = 0.69; P = 1, and P = 0.61, respectively). Our results do support the routine use of LM during total thyroidectomy.

Total thyroidectomy for benign thyroid disease

OBJECTIVES/HYPOTHESIS

The use of total thyroidectomy in thyroid cancer treatment is not unanimous, and it is even more controversial when this procedure is advocated for benign diseases. On the other hand, the complication risk may have an increase up to 20 times in repeat operations for recurrence. The objective of the study was to evaluate the use of total thyroidectomy in benign diseases, multinodular goiter, and Graves disease to justify the authors' preference.

STUDY DESIGN

Retrospective study of use of total thyroidectomy in benign diseases.

METHODS

Retrospective study of 1789 patients who underwent thyroidectomies from June 1990 to December 2000. Indication, extension of thyroidectomy, cancer incidence, and complications were analyzed.

RESULTS

Total thyroidectomy was performed in 81.19% of 456 patients with nontoxic multinodular goiter, 93.93% of 33 with toxic multinodular goiter, 93.93% of 66 with recurrent multinodular goiter, and 49.18% of 122 with Graves disease. Thyroid cancer was found in 16.62%, 9.09%, 3.03% and 5.73% of patients, respectively. Transitory and permanent hypoparathyroidism, hematoma requiring surgical intervention, and transitory and permanent recurrent laryngeal nerve injury occurred in 12.27%, 1.61%, 0.26%, 1.88%, and 0.35% of the patients undergoing total thyroidectomy, respectively. Permanent complications of total thyroidectomy for nontoxic multinodular goiter and Graves disease were similar to nontotal thyroidectomy. Use of total thyroidectomy for nontoxic multinodular goiter increased from 53.33% of the patient to 81.19%, on average, with a concomitant increase of cancer diagnosis from 11.11% to 16,62%. The authors performed total thyroidectomy for all patients with Graves disease.

CONCLUSION

Total thyroidectomy is the treatment of choice for multinodular goiter and thyroiditis, when there is bilateral gland involvement posterior to middle thyroid veins, and for Graves disease because it decreases the likelihood of future repeat operations for recurrent disease and thus the associated risks, when performed safely.

Postoperative hypocalcemia--the difference a definition makes

BACKGROUND

Review of the literature reveals considerable variability in the definitions and criteria used for reporting postoperative hypocalcemia. The lack of standardization prevents a meaningful comparison of results and performance locally with the national standard. It also prevents the pooling of data when performing meta-analysis, and may affect the comparison of research results.

METHODS

A literature review was performed to identify the different definitions used to define hypocalcemia in post-thyroidectomy patients. We analyzed the incidence of hypocalcemia in the same cohort of 202 post thyroidectomy patients using these definitions.

RESULTS

The reported hypocalcemia rates varied from 0% to 46% for the same cohort depending on the definition of hypocalcemia used. Only one-third of biochemically hypocalcemic patients requested calcium supplementation.

CONCLUSION

This study demonstrates the need for more uniformity and standardization in the definitions used for reporting hypocalcemia rates.

Prediction of hypocalcemia after using 1- to 6-hour postoperative parathyroid hormone and calcium levels: an analysis of pooled individual patient data from 3 observational studies

BACKGROUND

Parathyroid hormone (PTH) levels up to 6 hours postthyroidectomy have been shown to have excellent predictive power in determining hypocalcemia. In this study, we investigate the usefulness of combining calcium and PTH to increase the predictive power.

METHODS

Individual patient data were obtained from 3 studies (152 patients) that fulfilled our criteria (using PTH assay within hours postthyroidectomy to predict symptomatic hypocalcemia).

RESULTS

Changes in combined PTH and calcium threshold levels checked 1 to 6 hours after thyroidectomy were excellent in predicting postoperative hypocalcemia. A decrease in PTH of 60%, coupled with a simultaneous decrease in calcium of 10%, 5 to 6 hours postoperatively resulted in a sensitivity and specificity of 100%. However, combined PTH and calcium threshold changes were not significantly better than using PTH threshold changes alone.

CONCLUSIONS

Threshold changes in serum calcium and PTH, checked hours after surgery, can be used together to accurately predict whether a patient will become hypocalcemic after thyroidectomy.