Total thyroidectomy is associated with increased prevalence of permanent hypoparathyroidism

Preoperative Vitamin D and Calcium Administration in Patients Undergoing Thyroidectomy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Objective

This systematic review and meta-analysis aimed to assess whether preoperative administration of calcium and vitamin D prevents postoperative hypocalcemia.

Data Sources

A computerized search in Medline, Embase, and CENTRAL databases was performed.

Review Methods

Trials comparing preoperative calcium and vitamin D administration with either placebo or nothing were eligible for inclusion. The primary outcomes were the occurrence of laboratory hypocalcemia, mean postoperative calcium level, and symptomatic hypocalcemia. The secondary outcomes were the development of permanent hypoparathyroidism and length of hospitalization. Continuous outcomes were represented as standardized mean difference (SMD), and dichotomous outcomes were represented as risk ratio (RR).

Results

Nine trials that enrolled 1079 patients were found eligible. Postoperative laboratory hypocalcemia occurred less in patients who received preoperative calcium and vitamin D, but it was not statistically significant (RR = 0.77, 95% CI: 0.60-1.00; P = .05). Mean postoperative calcium level was significantly higher in the intervention group (SMD = 0.10, 95% CI: 0.07-0.12; P < .00001). The number of patients with symptomatic hypocalcemia was significantly lower in the intervention group (RR = 0.54, 95% CI: 0.38-0.76; P = .0005). There was no significant difference between the 2 groups in cases of permanent hypoparathyroidism and length of hospitalization.

Conclusion

Administration of calcium and vitamin D preoperatively achieves lower rates of postthyroidectomy symptomatic hypocalcemia in comparison with no intervention.

Hemithyroidectomy, does the indication influence the outcome?

PURPOSE

Hemithyroidectomies are mainly performed for two indications, either therapeutically to relieve compression symptoms or diagnostically for suspicious nodule(s). In case of the latter, one could consider the approach to be rather extensive since the majority of patients have no symptoms and will have benign disease. The aim of this study is to investigate the complication rates of diagnostic hemithyroidectomy and to compare it with the complication rates of compressive symptoms hemithyroidectomy.

METHODS

Data from patients who had undergone hemithyroidectomy either for compression symptoms or for excluding malignancy were extracted from a well-established Scandinavian quality register (SQRTPA). The following complications were analyzed: bleedings, wound infections, and paresis of the recurrent laryngeal nerve (RLN). Risk factors for these complications were examined by univariable and multivariable logistic regression.

RESULTS

A total of 9677 patients were included, 3871 (40%) underwent surgery to exclude malignancy and 5806 (60%) due to compression symptoms. In the multivariable analysis, the totally excised thyroid weight was an independent risk factor for bleeding. Permanent (6-12 months after the operation) RLN paresis were less common in the excluding malignancy group (p = 0.03).

CONCLUSION

A range of factors interfere and contribute to bleeding, wound infections, and RLN paresis after hemithyroidectomy. In this observational study based on a Scandinavian quality register, the indication "excluding malignancy" for hemithyroidectomy is associated with less permanent RLN paresis than the indication "compression symptoms." Thus, patients undergoing diagnostic hemithyroidectomy can be reassured that this procedure is a safe surgical procedure and does not entail an unjustified risk.

Recovery of parathyroid function in patients with thyroid cancer treated by total thyroidectomy: An analysis of 685 patients with hypoparathyroidism at discharge of surgery

OBJECTIVE

We aimed to study the predictive factors for recovery of parathyroid function in hypoparathyroid patients after total thyroidectomy for thyroid cancer.

METHODS

We designed a retrospective, multicentre and nation-wide analysis of patients with total thyroidectomy who were seen in twenty endocrinology departments from January to March 2018. We selected patients with histologically proven thyroid cancer and retrieved information related to surgical procedure and thyroid cancer features. Survival analysis and Cox regression analysis were used to study the relationship between these variables and the recovery of parathyroid function.

RESULTS

From 685 patients with hypoparathyroidism at discharge of surgery, 495 (72.3%) recovered parathyroid function over time. Kaplan-Meier analysis showed that this recovery was significantly related to the presence of specialized surgical team (P<0.001), identification of parathyroid glands at surgery (P<0.001), papillary histopathology (P=0.040), and higher levels of postoperative calcium (Ca) (P<0.001) and parathyroid hormone (PTH) (P<0.001). Subjects with gross extrathyroidal extension (P=0.040), lymph node metastases (P=0.004), and surgical re-intervention after initial surgery (P=0.024) exhibited a significant risk of persistence of hypoparathyroidism. Multivariate Cox regression analysis showed that the significant and independent factors for recovery of parathyroid function were postoperative concentrations of Ca (P=0.038) and PTH (P=0.049). The presence of lymph node metastases was a negative predictor of recuperation of parathyroid function (P=0.042) in this analysis.

CONCLUSION

In patients with thyroid cancer, recovery of parathyroid function after total thyroidectomy was directly related to postoperative Ca and PTH concentrations, and inversely related to lymph node metastases.

Measurement of serum intact parathyroid hormone concentration 1 day after total thyroidectomy to assess risk of permanent hypoparathyroidism

OBJECTIVE

This study was performed to assess the clinical value of measuring the intact parathyroid hormone (iPTH) concentration 1 day after total thyroidectomy to estimate the occurrence of permanent hypoparathyroidism (pHPP).

METHODS

Data of 546 patients who underwent total thyroidectomy from February 2008 to December 2018 were retrospectively analyzed. Calcium and iPTH concentrations were collected preoperatively and at 1 day and 6 months postoperatively. Logistic regression was used to analyze the correlation between clinical indexes and postoperative pHPP.

RESULTS

Of the 546 patients, 22 (4.03%) developed pHPP. Multivariate analysis showed that the iPTH and serum calcium concentrations measured 1 day after surgery were independent predictors of the risk of pHPP. An iPTH concentration of 5.51 pg/mL measured 1 day postoperatively was used as the cut-off value, and the area under the curve was 0.956. The risk of pHPP was identified with a sensitivity of 100%, specificity of 85.1%, positive predictive value of 22%, and negative predictive value of 100%.

CONCLUSIONS

The iPTH concentration measured 1 day after total thyroidectomy is closely related to the occurrence of pHPP postoperatively and is an independent predictive risk factor. The postoperative iPTH concentration can be helpful in identifying patients at risk for developing pHPP.

The significance of Hashimoto's thyroiditis for postoperative complications of thyroid surgery: a systematic review and meta-analysis

INTRODUCTION

Hashimoto's thyroiditis (HT) is one of the most common immune-mediated diseases. It makes thyroid surgery more complicated and difficult because there may be adhesions between the thyroid gland and surrounding structures. However, it is still controversial whether HT patients carry a high risk for postoperative complications of thyroid surgery. The purpose of this study was to investigate the significance of HT for the postoperative complications of thyroid surgery.

METHODS

A search for studies assessing the postoperative complication risks of HT patients compared with that of patients with benign nodules (BNs) was performed in PubMed, EMBASE and Web of Science. Nine studies (20,118 cases, 1,582 cases of HT and 18,536 cases of BN) were identified, and the data from the relevant outcomes were extracted and analysed.

RESULTS

There were no significant differences between the HT group and BN group in recurrent laryngeal nerve palsy (RLNP) and permanent hypoparathyroidism (PHP). The rate of transient hypocalcaemia (THC) was significantly higher in the HT group (16.85%) than in the BN group (13.20%).

CONCLUSIONS

The meta-analysis showed that HT only increased the risk of the postoperative complication THC compared to BN. Understanding the significance of HT in postoperative hypoparathyroidism after thyroid surgery would help clinicians perform sufficient preoperative (and postoperative) assessments and to optimise surgical planning.

Assessment of Visual and Brainstem Auditory Evoked Potentials in Patients with Hashimoto's Thyroiditis

BACKGROUND

The present study was aimed to evaluate parameters of visual and brainstem auditory evoked potentials (VEP, BAEP) in euthyreotic Hashimoto's thyroiditis (HT) patients without central nervous system involvement.

METHODS

100 HT patients (92 women, 8 men), mean age 46.9 years, and 50 healthy controls. They underwent a neurological examination, thyroid hormone levels, thyroid autoantibody titers, and brain imaging. Latencies and amplitudes of the N75, P100, and N145 component of VEP and the I-V components of BAEP were analyzed.

RESULTS

The neurological examination revealed in 31 patients signs of increased neurovegetative excitability. Brain resonance imaging showed no abnormalities in HT patients. The mean P100, relative P100, and N145 VEP latencies were significantly longer, and P100 amplitude significantly higher in HT patients than the controls. HT patients also had a longer mean wave BAEP V latency and mean wave III-V and I-V interpeak latencies, and significantly lower mean wave I and V amplitudes. Abnormal VEP and BAEP were recorded in 34% of the patients. There were no statistically significant correlations between the mean VEP parameters and thyroid profile and the applied dose of L-thyroxine. There was a relationship between the level of TSH and the wave BAEP III-V interpeak latency.

CONCLUSIONS

There were changes in the brain's bioelectrical activity in one-third of the patients with HT without nervous system involvement. The increased amplitude of the VEP may indicate increased cerebral cortex activity. Disorders of the brain's bioelectrical activity in the course of HT may be associated with an autoimmune process.

Post-Operative Permanent Hypoparathyroidism and Preoperative Vitamin D Prophylaxis

Permanent hypoparathyroidism, a feared thyroidectomy complication, leads to significant patient morbidity, medical treatment, and monitoring. This study explores whether preoperative high-dose vitamin D loading decreases the incidence of permanent hypoparathyroidism. In a subgroup analysis, the study examines the predictive utility of day 1 parathyroid hormone (PTH) in permanent hypoparathyroidism. Patients (n = 150) were previously recruited in the VItamin D In Thyroidectomy (VIDIT) trial, a multicentre, randomised, double blind, placebo-controlled trial evaluating the role of 300,000 IU cholecalciferol administered orally a week before total thyroidectomy. Patients were contacted postoperatively beyond six months through a telephonic questionnaire. The primary outcome was permanent hypoparathyroidism, strictly defined as the need for activated vitamin D six months postoperatively. Out of 150 patients, 130 (86.7%) were contactable. Permanent hypoparathyroidism occurred in 11/130 (8.5%) patients, with a lower incidence of 5.3% (3/57) in the cholecalciferol group compared to 11% (8/73) in the placebo group; however, this was non-significant (p = 0.34). In a subgroup analysis, no relationship between day 1 PTH level and the incidence of permanent hypoparathyroidism was found (p ≥ 0.99). There was a lower rate of permanent hypoparathyroidism in the cholecalciferol group, which was not significant. The predictive utility of day 1 postoperative PTH levels may be limited to transient hypoparathyroidism.

Prevalence and risk factors for hypoparathyroidism following total thyroidectomy in Spain: a multicentric and nation-wide retrospective analysis

PURPOSE

The prevalence of postoperative hypoparathyroidism has been studied in registries and in surgical series with highly variable and imprecise results. However, the frequency of this hormonal deficiency in the clinical practice of endocrinologists is not known with accuracy. We aimed to assess the prevalence and risk factors of hypoparathyroidism in patients undergoing total thyroidectomy in Spain.

METHODS

We designed a retrospective, multicentre and nation-wide protocol including all patients with total thyroidectomy who were seen in the endocrinology clinic of the participant centers from January to March 2018. Prevalence of hypoparathyroidism was evaluated at discharge of surgery, 3-6 months after surgery, 12 months after surgery and at last visit. Twenty hospitals participated in the study.

RESULTS

Of 1792 patients undergoing total thyroidectomy, 866 (48.3%) developed postoperative hypoparathyroidism at discharge of surgery. Most of them recover parathyroid function over time. Prevalence of hypoparathyroidism at 3-6 months, 12 months and at last visit was 22.9%, 16.7% and 14.5%, respectively. The risk of developing definitive hypoparathyroidism was related to the presence of parathyroid tissue at histology, lymph node dissection, and two-stage thyroidectomy. Patients with thyroid cancer, with higher postoperative calcium levels and treated by expert surgical teams exhibited lower risk of developing permanent hypoparathyroidism.

CONCLUSIONS

Although most patients with postsurgical hypoparathyroidism recover parathyroid function, the prevalence of permanent disease in clinical practice is non negligible (14.5%). Postoperative calcium, extent and timing of surgery, the presence of cancer, expert surgical team, and parathyroid tissue at histology are predictors of permanent hypoparathyroidism.

Hemithyroidectomy for benign euthyroid asymmetric nodular goitre

BACKGROUND

There is no consensus on the optimal surgery extent for patients with benign euthyroid asymmetric nodular goitre (AMNG).

METHODS

We reviewed medical literature using the PubMed engine to address the following issues: definition and prevalence, rationale for hemithyroidectomy, long-term outcomes, follow-up, revision surgery and image-guided thermal ablation of contralateral benign thyroid nodules following hemithyroidectomy for AMNG.

RESULTS

In total, 102 articles were found in MEDLINE using a keyword search strategy; subsequently, we selected 36 articles with clinical pertinence.

CONCLUSIONS

AMNG is a common clinical and surgical problem. Depending on the extent of the disease and individual surgeon preferences, either unilateral or bilateral thyroidectomy can be performed. Hemithyroidecomy can be considered for some patients with AMNG and the low risk of recurrent disease as a safer alternative to total thyroidectomy but it requires life-long follow-up, is associated with a higher recurrence risk and a need for revision thyroidectomy in selected subjects.

Huge variations in definition and reported incidence of postsurgical hypoparathyroidism: a systematic review

PURPOSE

The reported incidence of post surgical hypoparathyroidism (HypoPT) varies greatly. Previous research suggests that the definition of HypoPT is not consistent in the literature. We therefore conducted a systematic review to investigate how HypoPT is defined and whether this definition, as well as the selected threshold for hypocalcemia affects the incidence.

METHODS

Using a predefined search string we identified all articles in PubMed reporting on the incidence of postsurgical HypoPT from 1st January 2010 to January 2017.

RESULTS

We identified 89 articles that employed 20 different definition of HypoPT. The incidence of HypoPT varied from 0.0% to 20.2%. The definitions were not associated with incidence of HypoPT. Use of prophylactic post-operative calcium supplements, however decreased the risk of HypoPT (p = 0.03), and there was a trend towards a lower risk of HypoPT when using a definition of hypocalcemia below lower limit of the reference range (p = 0.09).

CONCLUSION

The large number of definitions of HypoPT, as well as the huge variation in incidence point to a problem suggests that the awareness of HypoPT should be raised. Use of prophylactic post-operative calcium supplements may decrease risk of HypoPT. This, however, may be due to reverse causality as awareness of the risk of HypoPT may promote the use of calcium supplementation.

Effects of Supplemental Perioperative Oxygen in Preventing Transient Hypoparathyroidism After Total Thyroidectomy

Background

Thyroidectomy is one of the most common endocrine procedures performed worldwide. Post-operative hypocalcemia is a troublesome complication of thyroid surgery. Few studies have considered the role of supplemental oxygen in preventing postoperative hypocalcemia in patients undergoing thyroidectomy.

Materials and methods

This was a randomized controlled study comparing the use of high flow supplemental oxygen (FiO₂ 80%) with low flow oxygen (FiO₂ 30%) in preventing transient postoperative hypocalcemia. Seventy-eight patients undergoing thyroidectomy during the year 2017 in Surgery Unit-1, Holy Family Hospital were included in the study.

Results

Transient hypoparathyroidism was present in 20.5% (n=8/39) in group 1 while it was present in 59.0% (n=23/39) in group 2 patients. Patients in group 1 (FiO₂ 80%) demonstrated a significantly lower percentage of transient hypoparathyroidism than group 2 (FiO₂ 30%) (P=0.001).

Conclusion

Our study concluded that high flow supplemental oxygen (FiO₂ 80%) significantly decreases the risk of developing postoperative transient hypocalcemia.

Ten-Year Follow-Up of a Randomized Clinical Trial of Total Thyroidectomy Versus Dunhill Operation Versus Bilateral Subtotal Thyroidectomy for Multinodular Non-toxic Goiter

Background

The aim of this study was to validate in a 10-year follow-up the initial outcomes of various thyroid resection methods for multinodular non-toxic goiter (MNG) reported in World J Surg 2010;34:1203–13.

Materials and methods

Six hundred consenting patients with MNG were randomized to three groups of 200 patients each: total thyroidectomy (TT), Dunhill operation (DO), bilateral subtotal thyroidectomy (BST). Obligatory follow-up period of 60 months was extended up to 120 months for all the consenting patients. The primary outcome measure was the prevalence of recurrent goiter and need for revision thyroid surgery. The secondary outcome measure was the cumulative postoperative and post-revision morbidity rate.

Results

The primary outcomes were twice as inferior at 10 years when compared to 5-year results for DO and BST, but not for TT. Recurrent goiter was found at 10 years in 1 (0.6%) TT versus 15 (8.6%) DO versus 39 (22.4%) BST (p < 0.001), and revision thyroidectomy was necessary in 1 (0.6%) TT versus 5 (2.8%) DO versus 14 (8.0%) BST patients (p < 0.001). Any permanent morbidity at 10 years was present in 5 (2.8%) TT patients following initial surgery versus 7 (4.0%) DO and 10 (5.7%) BST patients following initial and revision thyroidectomy (nonsignificant differences). At 10 years, 23 (11.5%) TT versus 25 (12.5%) DO versus 26 (13.0%) BST patients were lost to follow-up.

Conclusions

Total thyroidectomy can be considered the preferred surgical approach for patients with MNG, as it abolishes the risk of goiter recurrence and need for future revision thyroidectomy when compared to more limited thyroid resections, whereas the prevalence of permanent morbidity is not increased at experienced hands.

Registration number:

NCT00946894 (http://www.clinicaltrials.gov).

Parathyroid autotransplantation in thyroid surgery

BACKGROUND

Careful parathyroid gland dissection and in situ preservation was the time-honored approach to prevent parathyroid failure after total thyroidectomy. The relative success of parathyroid autotransplantation of hyperplastic parathyroid tissue in patients with renal or hereditary hyperparathyroidism did popularize the use of normal parathyroid tissue autografts during thyroidectomy to prevent permanent hypoparathyroidism. Proof of autograft function in this setting, however, is controversial.

PURPOSE

This narrative review aims at reviewing critically the current status of parathyroid autotransplantation during total thyroidectomy. It is also meant to analyze from the historical, methodological, and clinical points of view the claimed benefit of normal parathyroid gland autotransplantation. A focus is placed on the prevention of permanent hypoparathyroidism by parathyroid autotransplantation.

CONCLUSIONS

Liberal parathyroid autotransplantation was proposed in the mid 1970s but evidence of function is scarce. Proofs are accumulating that parathyroid autografts not only increase the rate of postoperative hypocalcemia, but may be also contribute to permanent hypoparathyroidism.

Nontoxic Multinodular Goitre and Incidental Thyroid Cancer: What Is the Best Surgical Strategy?-A Retrospective Study of 2032 Patients

OBJECTIVES

A discussion with regard to the most optimal surgical procedure in nontoxic multinodular goitre (NTMNG). We assessed and compared three main types of operations in 2032 patients with NTMNG.

METHODS

This is a retrospective study of 2032 patients operated on in one center due to NTMNG. The observation period was 48 to 120 months (mean and SD: 87 ± 20).

RESULTS

The early complications included uni- and bilateral recurrent laryngeal nerve paralysis (URLNP, BRLNP), overt tetany (OT), and postoperative bleeding (POB). We observed after TT, STT, and DO URLNP: 15 (1.73%), 3 (0.64%), and 2 (0.28%), respectively (p < 0.05); BRLNP: 3 (0.34%), 2 (0.43%), and 0 (0.0%), respectively (p = 0.25); OT: 42 (4.84%), 6 (1.29%), and 9 (1.28%), respectively (p < 0.0001); and POB: 11 (1.26%), 4 (0.86%), and 3 (0.42%), respectively (p = 0.209). Persistent complications we observed after TT, STT, and DO are the following: URLNP: 9 (1.03%), 3 (0.64%), and 1 (0.14%), respectively (p = 0.086); BRLNP: 1 (0.11%), 1 (0.21%), and 0 (0.0%), respectively (p = 0.51); and OT: 11 (1.26%), 2 (0.43%), and 2 (0.28%), respectively (p = 0.052). Incidental thyroid cancer (ITC) was recognized after TT, STT, and DO in 18 (2.07%), 21 (4.52%), and 11 (1.56%), respectively (p = 0.039). Recurrent goitre (RG) was observed in 1 (0.11%) after TT, 3 (0.64%) after STT, and 2 (0.28%) after DO (p = 0.234).

CONCLUSIONS

Performing less radical surgery in NTMNG is associated with a significantly lower risk of early and late URLNP and OT. In the case of BRLNP (early and persistent) and POB, no statistically significant differences are seen. The occurrence of ITC is higher following more radical surgeries. Less radical surgery is connected with a higher risk of RG.

Diagnosis and treatment of hypoparathyroidism: a position statement from the Brazilian Society of Endocrinology and Metabolism

Objective To present an update on the diagnosis and treatment of hypoparathyroidism based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Sociedade Brasileira de Endocrinologia e Metabologia (SBEM; Brazilian Society of Endocrinology and Metabolism) was invited to prepare a document following the rules set by the Guidelines Program of the Associação Médica Brasileira (AMB; Brazilian Medical Association). Relevant papers were retrieved from the databases MEDLINE/PubMed, LILACS, and SciELO, and the evidence derived from each article was classified into recommendation levels according to scientific strength and study type. Conclusion An update on the recent scientific literature addressing hypoparathyroidism is presented to serve as a basis for the diagnosis and treatment of this condition in Brazil.

Hypoparathyroidism: what is the best calcium carbonate supplementation intake form?

INTRODUCTION

In hypoparathyroidism, calcium supplementation using calcium carbonate is necessary for the hypocalcemia control. The best calcium carbonate intake form is unknown, be it associated with feeding, juice or in fasting.

OBJECTIVE

The objective was to evaluate the calcium, phosphorus and calcium×phosphorus product serum levels of hypoparathyroidism women after total thyroidectomy, following calcium carbonate intake in three different forms.

METHODS

A crossover study was carried out with patients presenting definitive hypoparathyroidism, assessed in different situations (fasting, with water, orange juice, breakfast with a one-week washout). Through the review of clinical data records of tertiary hospital patients from 1994 to 2010, 12 adult women (18-50 years old) were identified and diagnosed with definitive post-thyroidectomy hypoparathyroidism. The laboratory results of calcium and phosphorus serum levels dosed before and every 30min were assessed, for 5h, after calcium carbonate intake (elementary calcium 500mg).

RESULTS

The maximum peak average values for calcium, phosphorus and calcium×phosphorus product were 8.63mg/dL (water), 8.77mg/dL (orange juice) and 8.95mg/dL (breakfast); 4.04mg/dL (water), 4.03mg/dL (orange juice) and 4.12mg/dL (breakfast); 34.3mg²/dL² (water), 35.8mg²/dL² (orange juice) and 34.5mg²/dL² (breakfast), respectively, and the area under the curve 2433mg/dLmin (water), 2577mg/dLmin (orange juice) and 2506mg/dLmin (breakfast), 1203mg/dLmin (water), 1052mg/dLmin (orange juice) and 1128mg/dLmin (breakfast), respectively. There was no significant difference among the three different tests (p>0.05).

CONCLUSION

The calcium, phosphorus and calcium×phosphorus product serum levels evolved in a similar fashion in the three calcium carbonate intake forms.

Risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy: a retrospective Chinese population study

Background

Hypocalcemia is one of the most common postoperative complications following thyroid surgery in clinical practice. The occurrence of hypocalcemia is mainly attributed to hypoparathyroidism when parathyroid glands are devascularized, injured, or dissected during the surgery. The aim of this study was to analyze the risk factors for hypocalcemia and hypoparathyroidism following thyroidectomy.

Patients and methods

A total of 278 patients who underwent thyroid surgery were analyzed retrospectively. Univariate analysis and multivariable logistic regression were performed to discover the risk factors for hypocalcemia and hypoparathyroidism.

Results

Postoperative hypocalcemia occurred in 76 (27.3%) patients and hypoparathyroidism occurred in 42 (15.1%) patients. Seven factors were significantly related to the presence of postoperative hypocalcemia, namely, age (P=0.049), gender (P=0.015), lateral lymph node dissection (P=0.017), operation type (P<0.001), preoperative parathyroid hormone (PTH) level (P=0.035), operation time (P=0.001), and applying carbon nanoparticles (CNs; P=0.007). Our result revealed that gender (P=0.014), lateral lymph node dissection (P=0.038), operation type (P<0.001), operative time (P<0.001), and applying CNs (P=0.001) had a significant correlation with postoperative hypoparathyroidism.

Conclusion

These findings were crucial for guiding surgeons to prevent the occurrence of hypocalcemia and hypoparathyroidism.

Perioperative determinants of transient hypocalcemia after pediatric total thyroidectomy

PURPOSE

We seek to identify risk factors associated with hypocalcemia after pediatric total thyroidectomy.

METHODS

We retrospectively reviewed patients younger than 21years undergoing total thyroidectomy between January 2002 and January 2016. We defined hypocalcemia as any serum calcium <8mg/dl or ionized calcium <1.0mmol/L. Perioperative risk factors were identified through multivariate logistic regression.

RESULTS

Ninety-one children underwent total thyroidectomy. The average age was 13.7±4.4years, and 77% were female. Transient hypocalcemia was diagnosed in 34% (n=31) of patients. There was one case of permanent hypoparathyroidism. Predictors of transient hypocalcemia included age (OR 0.87, 95% CI 0.8-0.97, p=0.01), lymphadenectomy (OR 6.6, 95% CI 1.7-31.6, p=0.01), and hyperthyroidism (OR 13.3, 95% CI 1.3-1849, p=0.03). Patients with malignancy undergoing central (OR 7.1, 95% CI 1.5-33.4, p=0.01) or central plus lateral lymphadenectomy (OR 6.33, 95% CI 1.0-40.1, p=0.05) had significantly increased risk for transient hypocalcemia. Malignancy, MEN2A/B, goiter, preoperative calcium supplementation, incidental parathyroid removal, and postoperative PTH <15pg/ml were not associated with transient hypocalcemia.

CONCLUSIONS

Younger age, hyperthyroidism, and concomitant lymphadenectomy during total thyroidectomy increase risk of developing transient hypocalcemia. Malignant cases with central or central plus lateral lymphadenectomy are also at increased risk. Aggressive perioperative management of hypocalcemia should be initiated in patients with these risk factors.

LEVEL OF EVIDENCE

2b.

The Tubercle of Zuckerkandl : An Important Landmark Revisited

To study the incidence of the tubercle of Zuckerkandl (ZT) among Indian patients subjected to thyroid surgery at a tertiary care cancer centre and its relevance in localization of recurrent laryngeal nerve (RLN). Prospective study on 144 patients (48 males, 96 females) undergoing thyroidectomy (35 hemithyroidectomies, 109 total thyroidectomies) from September 1st 2010 - February 28th 2013. 144 specimen/253 lobes (129 right, 124 left) were evaluated. Findings were recorded by the same team to ensure consistency. Presence, shape, grade (Pelizzo's) of ZT and relationship to RLN were documented. ZT was identified in 90.5 % (n = 229), commoner on the right (n = 120) than on left (n = 109). ZT was Grade 0 in 9.5 %, Grade I in 28.9 %, Grade II in 50.5 % and Grade III in 11 % of cases. In all patients ZT was unilobed. Recurrent laryngeal nerve (RLN) was consistent in position and was posterior to ZT in all cases. There were no branches of the RLN above the ZT. The ZT is a useful guide in locating RLN. Surgeon should be aware about the incidence, shape, grade and relation to RLN which is different in the Indian population as compared to what has been reported globally.

Association between decreased serum parathyroid hormone after total thyroidectomy and persistent hypoparathyroidism

Background

Postoperative hypocalcemia caused by hypoparathyroidism is one of the most common morbidities of total thyroidectomy. The aim of this study was to analyze the kinetics and factors affecting PTH levels after total thyroidectomy and central neck dissection (CND).

Material/Methods

We performed a retrospective study in 438 consecutive patients who underwent total thyroidectomy between January 2007 and December 2010. No patient had a history of thyroid or neck surgery. PTH and calcium levels were recorded 1 day before the operation, during the first 5 days, and during follow-up (2 weeks and 2, 6, and 12 months).

Results

PTH levels declined to 41.90% of its initial value on the first day after the operation. After surgery, PTH was correlated positively with calcium and inversely with phosphate levels from postoperative day 1 to 14. Based on clinical observation, using a PTH threshold of <7 ng/L on postoperative day 1 was predictive of persistent hypoparathyroidism, with sensitivity and negative predictive value 100%, but poor specificity (70.19%). CND increased the risk of transient hypoparathyroidism compared with total thyroidectomy alone. Patients with thyroiditis had an increased risk of permanent hypoparathyroidism compared with those without thyroiditis. Iatrogenic removal of the parathyroid glands increased the risk of permanent hypoparathyroidism compared with those without iatrogenic parathyroidectomy.

Conclusions

PTH declined on the first day after thyroidectomy. PTH levels <7 ng/L on the first day after surgery might be associated with persistent hypoparathyroidism. CND, thyroiditis, and iatrogenic parathyroidectomy increased the risk of hypoparathyroidism.

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.