Hypocalcemia following thyroid surgery: incidence and risk factors. A longitudinal multicenter study comprising 2,631 patients

Video-assisted parathyroid gland mapping with autofocusing

Preservation of the parathyroid gland (PTG) in neck endocrine surgery is important for regulating the amount of calcium in the blood and within the bones. Localization of the PTG has been attempted using various methods such as ultrasound, sestamibi, computerized tomography, magnetic resonance imaging and indocyanine green fluorescence imaging. These methods cannot be used during surgery, have high sensitivity or have PTG specificity. However, autofluorescence technique has shown high sensitivity and does not require exogenous contrast. In this study, a new optical system was designed and developed into a clinical system. The system enabled easier and faster focusing on the surgical area and high-resolution video imaging while maintaining a clear image. The system was located above the head of the surgeon. The surgeon was able to see the real-time autofluorescent image on the monitor next to the operating table at any time to locate the PTG. The PTG buried in the adipose tissue and connective tissue was located easily and accurately. The clinical trial conducted in this study consisted of 56 parathyroid cases in 26 patients. For the statistical results, the sensitivity and accuracy in this redesigned autofluorescent imaging system were 98.1% and 96.4%, respectively.

The injury of recurrent laryngeal nerve and thyroid regeneration after irreversible electroporation ablation of most part of thyroid gland-an experimental study on swine model

To study the thyroid regeneration and injury of recurrent laryngeal nerve after irreversible electroporation (IRE). 12 pigs were divided into three groups: six pigs underwent IRE, other pigs were used as controls. IRE was performed near tracheoesophageal groove, to ablate most part of thyroid gland. Parathyroid and thyroid function, recurrent laryngeal nerve injury and thyroid computed tomography (CT) imaging were regularly investigated. The histopathology results were analyzed to detect thyroid regeneration. Masson's trichrome method for collagen and immunohistochemistry were performed for Soluble protein-100 (S100) and neurofilaments on nerve section. In IRE group, there were no symptoms of recurrent laryngeal nerve-related injury. No abnormalities of recurrent laryngeal nerve were shown on hematoxylin-eosin (HE) staining, Masson's trichrome staining, Neurofilament (NF) staining and S100 staining. There were no significant changes for thyroid and parathyroid function in all pigs. Immediately after IRE, CT showed hypoattenuation in the ablated thyroid gland and it became swelling. 14 days after IRE, thyroid CT showed hetergenous attenuation in the electroporation zone, and the size and attenuation of thyroid gland were normal after two months. There was cell apoptosis in the thyroid gland after IRE. Seven and 14 days after IRE, there was fragmentation of nucleus within the follicle, and some follicles were empty. Two months later, complete regeneration of thyroid tissue was shown. IRE was shown to be both effective and safe with complete regeneration of thyroid tissue and preservation of the function and structure of the recurrent laryngeal nerve.

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.

Ultrasonography of Injury to the Parathyroids During a Thyroidectomy

Objective:

Explore the characteristics of parathyroid injury during thyroid surgery and the potential for sonography to reduce the risk of parathyroid injury.

Methods:

Retrospective analysis was conducted on 39 patient cases, with parathyroid injury (including 29 cases of total thyroidectomy plus central lymph node dissection and 10 cases of total thyroidectomy). Sonography and related medical laboratory testing were performed pre- and postsurgery. Clinical symptoms and associated postsurgical gland changes were compared and analyzed according to the relevant laboratory values.

Results:

The patient case review demonstrated that the total number of glands decreased by 43 compared with preoperation, with 25 glands in the upper pair and 18 glands in the lower. There were 33 glands with uneven echo and blurred edges, with 20 in the upper pair and 13 in the lower pair. The damage rate of the upper gland (45/76) was higher than that of the lower gland (31/76) ( P < .05). A total of 69.7% (23/33) of gland blood flow signals were reduced compared with preoperation, of which 10 showed uneven enhancement when the contrast-enhanced ultrasound reached its peak.

Conclusion:

Thyroid surgery can easily damage parathyroid glands, especially during a total thyroidectomy, with lymph node dissection. Sonography of the parathyroid glands in patients with postoperative hypocalcemia can provide imaging surveillance and mitigate the damage of these glands postsurgically.

Magnesemia: an independent risk factor of hypocalcemia after thyroidectomy

Background

This study was designed to investigate the impact of serum magnesium (Mg) levels on hypocalcemia after thyroidectomy.

Patients and methods

In total, 242 patients with differentiated thyroid cancer were retrospectively analyzed.

Results

Multivariate regression analysis showed hypomagnesemia was an independent risk factor for hypocalcemia (P<0.001). While Mg in low levels (0.66 mmol/L ≤ Po-Mg ≤0.74 mmol/L) increased the risk of hypocalcemia, postoperative serum Ca (Po-Ca) levels were significantly lower in patients with hypomagnesemia than in patients with normomagnesemia (P=0.01), and the former patients suffered significant decreases in serum Ca (P=0.02). Compared to patients with a mild decline of serum Mg after surgery (ΔMg <0.17), serum Ca decline significantly increased (P<0.001) in patients with a severe decline of serum Mg (ΔMg ≥0.17), while the change in amounts of parathyroid hormone (PTH) after surgery was similar between the two groups (P>0.05). In patients with normal Po-Ca levels, hypomagnesemia increased the risk of symptoms related to hypocalcemia by 4.478 times (OR =5.478, 95% CI 1.724–17.403).

Conclusion

Hypomagnesemia, or even a low serum Mg level within the normal range, can increase the risk of hypocalcemia. After excluding the potential effects of PTH on serum magnesium and calcium, serum Mg reduction is one of the most important factors that influences postoperative serum Ca reduction. What’s more, hypomagnesemia is closely linked with symptoms.

Correlation between iPTH Levels on the First Postoperative Day After Total Thyroidectomy and Permanent Hypoparathyroidism: Our Experience

Permanent hypoparathyroidism is the most common long-term complication after thyroidectomy. We evaluated whether iPTH concentrations on the first postoperative day may be a good predictor of this complication.

Patients undergoing thyroidectomy in our Unit between January 2017 and February 2018 who developed postsurgical hypoparathyroidism were analysed. According to iPTH values on the first postoperative day and on the basis of the detection threshold of the iPTH test used, patients were divided into 2 groups: Group A (iPTH < 6.3 pg/mL, undetectable), Group B (iPTH ≥ 6.3 pg/mL).

Seventy-five patients were included in this study: 64 in Group A and 11 in Group B. Permanent hypoparathyroidism occurred in 14 (21.88%) patients in Group A, while none developed this complication in Group B. When iPTH was < 6.3 pg/mL, the sensitivity for the prediction of permanent hypoparathyroidism was 100%, the specificity was 18.03%, the positive predictive value was 21.88% and the negative predictive value was 100%.

No patient with iPTH ≥ 6.3 pg/mL on the first postoperative day developed permanent hypoparathyroidism. On the other hand, iPTH concentrations < 6.3 pg/mL have not proved to be a strong predictor of this condition. However, this cut-off value can be useful to identify patients at risk of developing this complication.

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.

Complications after reoperative thyroid surgery: retrospective evaluation of 152 consecutive cases

Reoperative thyroid surgery is an uncommon procedure that is indicated in recurrent benign or malignant disease. It is associated with a high complication rate, especially of hypoparathyroidism and recurrent nerve palsy. We retrospectively reviewed our series of patients on whom reoperative thyroid surgery was performed and we compared this group with patients who underwent primary thyroidectomies. From 2002 to 2015, 4572 thyroidectomies were performed at our institution; among these, 152 (3.3%) were for benign or malignant recurrent disease. We observed a higher rate of transient hypoparathyroidism in secondary vs primary surgery (56.6% vs 25.9%; p < 0.0001), of permanent hypoparathyroidism (10% vs 2.0%; p < 0.0001) and of transient recurrent nerve injury (4.6% vs 1.4%; p < 0.05). Reoperative thyroid surgery is a technical challenge with a high incidence of complications. Scarring, edema, and friability of the tissues together with distortion of the landmarks make reoperative surgery hazardous. Careful assessment of patient's risk factors, physical examination, and if necessary fine needle aspiration cytology are crucial for selecting the patients who should undergo reoperation. Research registry n. 2617 registered 5 June 2017 (retrospectively registered).

Intraoperative rapid aspiration cytological method for parathyroid glands identification and protection

To explore new methods for intraoperative identification of parathyroid glands, 86 thyroid cancer patients, admitted to Xijing hospital from July 2017 to July 2018, were included. During lymph node dissection, parathyroid glands were firstly judged by clinician eyeballing, based on his clinical experience. Then, cytological detection was used for rapid identification via Diff-quik staining. PTH monitoring was performed by PTH detection kit. Finally, frozen pathology was examined and regarded as the golden standard. In this study, 172 suspicious parathyroid glands were observed. According to frozen pathology outcome, the accuracy, sensitivity and specificity of clinician eyeballing were calculated as 63.3%, 100%, and 13.9%. Kappa test showed poor consistency (kappa = 0.156), AUC area was 0.569 ± 0.045, 95%CI = (0.480-0.658), p = 0.123. For cytological and PTH detection, the accuracy, sensitivity and specificity were 91.7% vs. 92.3%, 93.6% vs. 93.8% and 89.0% vs. 90.3%. Kappa value was 0.829 vs. 0.842, indicating good consistency. AUC area was 0.908 ± 0.027 vs. 0.918 ± 0.025, 95%CI = (0.856-0.960) vs. (0.869-0.966), p < 0.001, indicating higher diagnositic value. Besides, compared with frozen pathology, cytological detection was easily and rapid. The time-taking between frozen pathology and cytological detection or PTH detection were 39.0 ± 6.59 min vs. 5.02 ± 0.78 min and 39.0 ± 6.59 min vs. 6.1 ± 1.23 min, p < 0.001. In conclusion, intra-operative cytological detection maybe potential for in-situ preservation of parathyroid glands.

Parathyroid autotransplantation at a novel site for better evaluation of the grafted gland function: study protocol for a prospective, randomized controlled trial

Background

Hypoparathyroidism is one of the most common complications encountered in thyroidectomy. In addition to parathyroid in-situ preservation, parathyroid autotransplantation (PA) is another important remedial method for patients whose parathyroid glands have been removed. However, an accurate evaluation method for the function of a transplanted parathyroid is lacking. Our preliminary study indicated that patients with PA at novel sites near antecubital veins had higher serum concentrations of parathyroid hormone (PTH). Therefore, the main hypothesis is that a grafted site closer to the cephalic vein is more useful for better evaluation of transplanted parathyroid function. This study aims to confirm the more efficient and accurate evaluation system through a prospective, randomized controlled trial.

Methods

In total, 280 patients will be enrolled in this study and randomly divided into two groups: 140 patients with transplanted parathyroid glands in the traditional sites (group A) and the other 140 transplanted in the novel sites (group B), close to the antecubital veins. The serum concentration of PTH and calcium ion from both forearms will be measured and monitored regularly for 12 months. The primary outcome of this trial will be the survival of grafted glands, defined as the ratio of PTH between the grafted vs. the non-grafted forearms being no less than 1.5. The secondary outcome is hypoparathyroidism, defined as the PTH level from the non-grafted forearms being less than 15 pg/ml (normal range 15–65 pg/ml).

Discussion

Our results from this study should provide a more accurate method to evaluate the function of transplanted parathyroid glands by comparing PTH concentrations in both the grafted and non-grafted forearms following PA at novel sites. A better PTH measurement is helpful not only for the management of postoperative patients, but also for further identification of factors affecting PA success.

Trial registration

ClinicalTrials.gov, ID: NCT02906748. Registered on 16 March 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3195-9) contains supplementary material, which is available to authorized users.

One-Hour Postoperative Parathyroid Hormone Levels Do Not Reliably Predict Hypocalcemia After Thyroidectomy

INTRODUCTION

Hypocalcemia is a well-known complication after total thyroidectomy. Studies have indicated that the presence of low postoperative parathyroid hormone (PTH) levels can predict hypocalcemia. However, definitive study designs are lacking. The aim of this study was to determine whether postoperative PTH alone can accurately predict postoperative biochemical hypocalcemia.

METHODS

Under IRB approval, a prospective study of 218 consecutive patients who underwent total or completion thyroidectomy by two surgeons between June 2014 and June 2016 was performed. Biochemical hypocalcemia was defined as ionized calcium <1.13 mmol/L or serum calcium <8.4 mg/dL at any time postoperatively. Three PTH thresholds, <10, <20 pg/mL, and >50% drop in PTH 1 h postoperatively from baseline were examined.

RESULTS

Postoperative PTH < 10 pg/mL had a sensitivity of 36.5% (95% CI 27.4-46.3%) and a specificity of 89.2% (95% CI 81.9-94.3%). Postoperative PTH < 20 pg/mL had a sensitivity of 66.4% (95% CI 56.6-75.2%) and a specificity of 67.6% (95% CI 58.0-76.2%). Postoperative PTH decrease >50% had a sensitivity of 63.4% (95% CI 53.2-72.7%) and a specificity of 72.5% (95% CI 62.5-81.0%). Across all PTH thresholds, the false-negative rate was 33.6-63.5% indicating that up to 64% of patients with a normal PTH level could have been discharged without appropriate calcium supplementation. The false-positive rate was 10.8-32.4% indicating that up to 32.4% of patients with low PTH could have been treated with calcium supplementation unnecessarily.

CONCLUSION

Following total thyroidectomy, PTH levels are unreliable in predicting hypocalcemia. Additional prospective studies are needed to understand the true utility of PTH levels post-thyroidectomy.

The timing of parathyroid hormone measurement defines the cut-off values to accurately predict postoperative hypocalcemia: a prospective study

PURPOSE

Serum intact parathyroid hormone (iPTH) level is an early marker of post-thyroidectomy hypocalcemia. However, lack of methodological standardization to define timing and cut-off points of iPTH measurement limit its clinical applicability. Here, we evaluated the relationship between two distinct postoperative time sampling and iPTH accuracy on predicting hypocalcemia.

METHODS

iPTH was measured within 4 h after surgery (iPTH 4 h) and on the morning of the first postoperative day (iPTH 1st PO). Hypocalcemia was defined by levels of total calcium corrected by serum albumin ≤ 8.0 mg/dL and/or by the presence of symptoms. The most accurate iPTH cut-off point for hypocalcemia prediction was established from a ROC curve comparing both time-points.

RESULTS

The study included 101 patients. The mean age was 52.4 ± 12.9 years, 93 were women (92.1%) and 69 patients underwent total thyroidectomy (68.3%). Hypocalcemia occurred in 25 patients (24.8%), of whom 12 were symptomatic. Total thyroidectomy, longer duration of surgery, surgical complications related to parathyroid glands and lower levels of iPTH 4 h and iPTH 1st PO were associated with postoperative hypocalcaemia (all P < 0.05). Using the ROC curve, the optimal cut-off points were 19.55 pg/mL and 14.35 pg/mL for iPTH 4 h and iPTH 1st PO, respectively. The comparison of the AUC showed no significant difference between these two points of evaluation (0.935 vs. 0.940; P = 0.415).

CONCLUSIONS

Serum iPTH levels measured within 4 h or on the first morning after surgery are predictors of postoperative hypocalcemia. Notably, both time-points have the same accuracy to predict postoperative hypocalcemia (with different cutoff points).

Randomized clinical trial of intraoperative parathyroid gland angiography with indocyanine green fluorescence predicting parathyroid function after thyroid surgery

BACKGROUND

Hypoparathyroidism, the most common complication after thyroid surgery, leads to hypocalcaemia and significant medical problems. An RCT was undertaken to determine whether intraoperative parathyroid gland angiography with indocyanine green (ICG) could predict postoperative hypoparathyroidism, and obviate the need for systematic blood tests and oral calcium supplementation.

METHODS

Between September 2014 and February 2016, patients who had at least one well perfused parathyroid gland on ICG angiography were randomized to receive standard follow-up (measurement of calcium and parathyroid hormone (PTH) on postoperative day (POD) 1 and systematic supplementation with calcium and vitamin D; control group) or no supplementation and no blood test on POD 1 (intervention group). In all patients, calcium and PTH levels were measured 10-15 days after thyroidectomy. The primary endpoint was hypocalcaemia on POD 10-15.

RESULTS

A total of 196 patients underwent ICG angiography during thyroid surgery, of whom 146 had at least one well perfused parathyroid gland on ICG angiography and were randomized. None of these patients presented with hypoparathyroidism, including those who did not receive calcium supplementation. The intervention group was statistically non-inferior to the control group (exact 95 per cent c.i. of the difference in proportion of patients with hypocalcaemia -0·053 to 0·053; P = 0·012). Eleven of the 50 excluded patients, in whom no well perfused parathyroid gland could be identified by angiography, presented with hypoparathyroidism on POD 1, and six on POD 10-15, which was significantly different from the findings in randomized patients (P = 0·007).

CONCLUSION

ICG angiography reliably predicts the vascularization of the parathyroid glands and obviates the need for postoperative measurement of calcium and PTH, and supplementation with calcium in patients with at least one well perfused parathyroid gland. Registration number: NCT02249780 (http://www.clinicaltrials.gov).

Optimization of the risk-benefit ratio of differentiated thyroid cancer treatment

The vast majority of differentiated thyroid cancers (DTC) are characterized by an innocuous nature, excellent patient survival, and limited treatment requirement. However, a significant proportion of affected patients is prone to receiving overtreatment, due to undertreatment concerns associated with the difficulty to differentiate them from a small minority affected by aggressive DTC. Identification of prognostic factors and development of staging systems has helped to reduce the proportion of overtreatment in DTC. However, the absolute number of overtreated patients continues to increase, as a result of an on-going incidence surge in early DTC associated with the increased application and sensitivity of modern diagnostic tools. In the present paper, we describe how DTC treatment can be optimized by thoughtful evidence-based balancing of oncologic safety against treatment associated morbidity.

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.

To identify or not to identify parathyroid glands during total thyroidectomy

Hypoparathyroidism is one of the most common complications after total thyroidectomy and may impose a significant burden to both the patient and clinician. The extent of thyroid resection, surgical techniques, concomitant central neck dissection, parathyroid gland (PG) autotransplantation and inadvertent parathyroidectomy have long been some of the risk factors for postoperative hypoparathyroidism. Although routine identification of PGs has traditionally been advocated by surgeons, recent evidence has suggested that perhaps identifying fewer number of in situ PGs during surgery (i.e., selective identification) may further lower the risk of hypoparathyroidism. One explanation is that visual identification may often lead to subtle damages to the nearby blood supply of the in situ PGs and that may increase the risk of hypoparathyroidism. However, it is worth highlighting the current literature supporting either approach (i.e., routine vs. selective) remains scarce and because of the significant differences in study design, inclusions, definitions and management protocol between studies, a pooled analysis on this important but controversial topic remains an impossible task. Furthermore, it is worth nothing that identification of PGs does not equal safe preservation, as some studies demonstrated that it is not the number of PGs identified, but the number of PG preserved in situ that matters. Therefore a non-invasive, objective and reliable way to localize PGs and assess their viability intra-operatively is warranted. In this aspect, modern technology such as the indocyanine green (ICG) as near-infrared fluorescent dye for real-time in situ PG perfusion monitoring may have a potential role in the future.

A reappraisal of vascular anatomy of the parathyroid gland based on fluorescence techniques

Identification of the parathyroid glands (PGs) during thyroid surgery may prevent their inadvertent surgical removal and prevent postoperative hypoparathyroidism. However, identification of the PGs does not guarantee their function, and their vascular supply needs to be preserved as well. The recent introduction of intraoperative indocyanine green (ICG) fluorescent angiography of the PGs during thyroid surgery allows for the appraisal of the vascular anatomy and evaluation of PG function. The use of this tool could lead to a significant reduction in the rate of postoperative hypoparathyroidism, as it allows surgeons to adapt their surgical technique for the preservation of the PGs. ICG fluorescent angiography is currently the only available real-time tool to assess the vascular blood supply of each individual PG intraoperatively and can thus assist surgeons in their decision-making. Herein, we review the relevant literature.

Incidence, prevalence and risk factors for post-surgical hypocalcaemia and hypoparathyroidism

Hypocalcaemia following thyroid surgery is common and is associated with significant short and long term morbidity. Damage to or devascularisation of parathyroid glands is the predominant underlying mechanism; although other factors such as hungry bone syndrome may occasionally contribute to it in the immediate post-operative period. The reported incidence of post-surgical hypocalcaemia and/or hypoparathyroidism (PoSH) varies significantly in the literature; the variation thought to be at least partly due to differences in the definitions used. Figures on the prevalence of chronic or long term post-surgical hypocalcaemia in the population are unclear. Risk factors for PoSH have been extensively studied in recent years and may be classified into patient, disease and surgery related factors. Some risk factors are modifiable; but both modifiable and non-modifiable factors help in generating a risk profile that may be used to select patients for preventative measures and/or changes in surgical strategy. This narrative review discusses recent literature on the incidence, prevalence and risk factors for PoSH.

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.

Does intraoperative neuromonitoring of recurrent nerves have an impact on the postoperative palsy rate? Results of a prospective multicenter study

BACKGROUND

The impact of intraoperative neuromonitoring on recurrent laryngeal nerve palsy remains debated. Our aim was to evaluate the potential protective effect of intraoperative neuromonitoring on recurrent laryngeal nerve during total thyroidectomy.

METHODS

This was a prospective, multicenter French national study. The use of intraoperative neuromonitoring was left at the surgeons' choice. Postoperative laryngoscopy was performed systematically at day 1 to 2 after operation and at 6 months in case of postoperative recurrent laryngeal nerve palsy. Univariate and multivariate analyses and propensity score (sensitivity analysis) were performed to compare recurrent laryngeal nerve palsy rates between patients operated with or without intraoperative neuromonitoring.

RESULTS

Among 1,328 patients included (females 79.9%, median age 51.2 years, median body mass index 25.6 kg/m²), 807 (60.8%) underwent intraoperative neuromonitoring. Postoperative abnormal vocal cord mobility was diagnosed in 131 patients (9.92%), including 69 (8.6%) and 62 (12.1%) in the intraoperative neuromonitoring and nonintraoperative neuromonitoring groups, respectively. Intraoperative neuromonitoring was associated with a lesser rate of recurrent laryngeal nerve palsy in univariate analysis (odds ratio = 0.68, 95% confidence interval, 0.47; 0.98, P = .04) but not in multivariate analysis (oddsratio = 0.74, 95% confidence interval, 0.47; 1.17, P = .19), or when using a propensity score (odds ratio = 0.76, 95% confidence interval, 0.53; 1.07, P = .11). There was no difference in the rates of definitive recurrent laryngeal nerve palsy (0.8% and 1.3% in intraoperative neuromonitoring and non-intraoperative neuromonitoring groups respectively, P = .39). The sensitivity, specificity, and positive and negative predictive values of intraoperative neuromonitoring for detecting abnormal postoperative vocal cord mobility were 29%, 98%, 61%, and 94%, respectively.

CONCLUSION

The use of intraoperative neuromonitoring does not decrease postoperative recurrent laryngeal nerve palsy rate. Due to its high specificity, however, intraoperative neuromonitoring is useful to predict normal vocal cord mobility. From the CHU de Nantes,^a Clinique de Chirurgie Digestive et Endocrinienne, Nantes, France; CHU Lille, Université de Lille,^b Chirurgie Générale et Endocrinienne, Lille, France; CHU Nancy-Hôpital de Brabois,^c Service de Chirurgie Digestive, Hépato-Biliaire, et Endocrinienne, Nancy, France; CHU Angers,^d Chirurgie Digestive et Endocrinienne, Angers, France; CHU de Toulouse-Hôpital Larrey,^e Chirurgie Thoracique, Pôle Voies Respiratoires, Toulouse; CHU Saint-Etienne-Hôpital Nord,^f ORL et Chirurgie Cervico-Faciale et Plastique, Saint-Etienne, France; CHU de Limoges-Hôpital Dupuytren,^g Chirurgie Digestive, Générale et Endocrinienne, Limoges, France; CHU de Besançon-Hôpital Jean Minjoz,^h Chirurgie Digestive, Besançon, France; Centre Hospitalier du Mans,ⁱ Service ORL et Chirurgie Cervico-Faciale, Le Mans, France; Centre Hospitalier Lyon-Sud,^j Chirurgie Générale, Endocrinienne, Digestive et Thoracique, Pierre Bénite, France; AP-HM-Hôpital de La Conception,^k Chirurgie Générale, Marseille, France; CHU de Rennes-Hôpital Pontchaillou,^l Service ORL et Chirurgie Maxillo-Faciale, Rennes, France; CHU de Caen,^m ORL et Chirurgie Cervico-Faciale, Caen, France; CHU d'Angers,ⁿ ORL et Chirurgie Cervico-Faciale, Angers, France; CHU de Nantes,^o Service ORL, Nantes, France; AP HP URCEco île-de-France,^p hôpital de l'Hôtel-Dieu, Paris, France; DRCI, département Promotion,^q Nantes, France.

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.

Management of tyrosine kinase inhibitors (TKI) side effects in differentiated and medullary thyroid cancer patients

Four tyrosine kinase inhibitors (TKIs) have been recently licensed in thyroid cancer (TC), sorafenib and lenvatinib for differentiated TC, vandetanib and cabozantinib for medullary TC. Others TKIs such as axitinib, pazopanib, sunitinib, have been tested within phase II trials. The toxicity burden associated to TKIs is not negligible. Drug reductions and interruptions are common, definitive drug withdrawals have also been reported as well as toxic deaths in more rare cases. In this context, the prevention of toxicities is mandatory to allow patients to stay on treatment as long as possible without dose and schedule modifications. Both physicians and patients should be educated to recognize drug-related toxicities in order to manage them in an early phase. Tools (e.g. toxicities summary booklet) for physicians and patients could be considered to improve the knowledge on side effects management. Guidelines, whenever available, should be followed.

Randomized clinical trial of ultrasonic scissors versus conventional haemostasis to compare complications and economics after total thyroidectomy (FOThyr)

Background

The benefits of single‐use ultrasonic scissors in thyroid surgery are still debated. Although this device has been shown to reduce operating time compared with conventional haemostasis, its cost‐effectiveness has never been demonstrated. The aim of this study was to evaluate the efficacy, cost‐effectiveness and safety of ultrasonic scissors for total thyroidectomy.

Methods

This was a prospective, randomized, multicentre trial conducted at 13 hospital sites. The primary endpoint was the percentage of patients with hypocalcaemia (serum calcium level below 2 mmol/l) on day 2. Secondary endpoints included postoperative complications and costs, with calculation of incremental cost differences and cost‐effectiveness ratios.

Results

In total, 1329 patients who underwent total thyroidectomy were included in the analysis: 670 were randomized to treatment with ultrasonic scissors and 659 to conventional haemostasis. There was no difference between groups in the rate of complications, including hypocalcaemia on day 2 (19^.7 per cent in ultrasonic scissors group versus 20^.3 per cent in conventional haemostasis group; P = 0·743). Median operating times were significantly shorter with ultrasonic scissors (90 versus 100 min with conventional haemostasis; P < 0·001). Total mean(s.d.) direct costs at 6 months were €4311(1547) and €4011(1596) respectively (P < 0·001).

Conclusion

Ultrasonic scissors were no more clinically effective than conventional haemostasis, but use of these devices was more costly. Registration number: NCT01551914 (http://www.clinicaltrials.gov).

Analysis of factors affecting the development of hypocalcaemia after multinodular goitre surgery

INTRODUCTION

Thyroidectomy is a common surgery performed especially in treatment of multinodular goitre. The most common post-thyroidectomy complication is a postoperative hypocalcaemia, and the percentage of postoperative hypoparathyroidism could reach even 50%. Tested group and methods: A forward-looking, randomized testing was done on a group of 113 women being subject to multinodular goitre surgery. In this article, we wish to present an analysis of the results obtained in the control group, focusing on the predicative factors which determine the development of postoperative hypocalcaemia. Obtained results: The rate of postoperative biochemical hypocalcaemia development was significantly higher in the group of patients, where the preoperative calcium concentration was lower than 2,4 mmol/l. In that group, the development of biochemical hypocalcaemia was observed in 93,7% of cases (30 out of 32 patients), in comparison with 65,3% (17 out of 26) in the group of higher preoperative concentration of calcium. The highest risk of occurrence of postoperative hypocalcaemia was borne by the total thyroidectomy, while the lowest one by the subtotal thyroid lobectomy of one lobe only.

CONCLUSIONS

A higher preoperative concentration of calcium in blood serum is related to the lower rate of occurrence of postoperative biochemical hypocalcaemia. However, no such correlation was revealed in the case of postoperative symptomatic hypocalcaemia. Lack of correlation was determined between the preoperative concentration of TSH and FT4 in blood serum and the rate of occurrence of postoperative hypocalcaemia, both symptomatic and asymptomatic. The performed statistics did not reveal a relation between the postoperative hypocalcaemia and the duration of the surgery, but a significant correlation was stated with the scope of the performed surgery. Revealing a relation between the rate of occurrence of postoperative hypocalcaemia and the experience of the surgeon performing the surgery was not successful.

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.

The true cost of thyroid surgery determined by a micro-costing approach

Whether the amount of the current DRG tariff for thyroid surgery covers its actual cost has been questioned. We estimated a reliable cost of thyroid surgery for a large Italian hospital. A micro-costing approach is used with data from the University Hospital "Umberto I," a large facility that conducts a high volume of thyroidectomy surgical procedures in the Lazio region. The direct costs of surgery and hospitalization for a total and a hemi-thyroidectomy were €4956 and €4673, respectively. When compared to the DRG tariff of €3340, total thyroidectomy was €1616 (48 %) more per procedure and hemi-thyroidectomy was €1333 (40 %) more per procedure. This DRG shortfall is calculated to generate an annual procedure-specific deficit of approximately €1.38 million for this hospital. Furthermore, when the costs associated with pre-surgical work-up, post-surgical follow-up, and complications management through 12 months are incorporated, the estimated costs of total and hemi-thyroidectomy rose to €5812 and €5277, respectively. The true cost of thyroid surgery in Italy is significantly higher than what has been reported in the literature or reimbursed by the DRG tariff.

The Preservation and Autotransplantation of the Parathyroid Glands in Total Thyroidectomy in Patients With Thyroid Cancer—A Strategy for Avoiding Permanent Hypoparathyroidism

Hypoparathyroidism is a complication that occurs after total thyroidectomy (TT) in patients with thyroid cancer. We tried to determine a strategy for avoiding permanent hypoparathyroidism. A total of 42 patients underwent TT for thyroid cancer between April 2009 and March 2014. One or more parathyroid glands (PGs) could be macroscopically preserved in all of the patients. First, we evaluated the association between the number of PGs that were macroscopically preserved and the postoperative course in 28 patients without autotransplantation. The number of preserved PGs was not associated with postoperative tetany or the serum levels of calcium or phosphorous on postoperative day 1, or the proportion of patients who needed to take calcium supplements or a vitamin D analog. However, only the patients with a single preserved PG required calcium supplementation for longer than 1 year (33.3%, P &lt; 0.05). Next, we compared the clinical course with PG autotransplantation in 16 patients in whom a single PG was preserved. Although the result was not statistically significant, only the patients without autotransplantation required calcium supplementation for longer than 1 year. To avoid permanent hypoparathyroidism after TT, it should be essential to preserve at least 2 PGs or to preserve 1 PG and perform autotransplantation.

Usefulness of pre- and post-operative calcium and Vitamin D supplementation in prevention of hypocalcemia after total thyroidectomy: A randomized controlled trial

BACKGROUND

Total thyroidectomy (TT) is a commonly performed surgery and postoperative hypocalcemia is a major detriment to early discharge. The aim of this randomized controlled trial was to ascertain the usefulness of routine pre- and post-operative calcium and Vitamin D supplementation in prevention of hypocalcemia after TT.

MATERIALS AND METHODS

Sixty consecutive patients who underwent total or near TT from February 2013 to August 2014 were included in the study. They were randomly divided into two groups - Group 1 received oral calcium (500 mg every 6 h) and Vitamin D (calcitriol 0.25 mcg every 6 h) 7 days before and 7 days after the surgery; and Group 2 did not receive supplementation. Symptoms and signs of hypocalcemia were monitored. Calcium profile was measured pre- and post-operatively at 6, 12, 24, 48, 72 h, and on 30^th day. Hypocalcemia after surgery was either symptomatic or laboratory documented. Serum calcium level ≤ 8.5 mg/dl was considered as laboratory hypocalcemia.

RESULTS

Twelve patients from Group 2, and 3 patients from Group 1 developed symptomatic hypocalcemia (P < 0.01). Laboratory hypocalcemia within postoperative 24 h was comparable between two groups, but more patients of Group 2 compared to Group 1 developed hypocalcemia at 48 h (6 and 13, respectively; P = 0.04) and at 72 h after surgery (5 and 14, respectively; P = 0.01). Twenty-four hours postoperative serum calcium level was significantly associated with grade of goiter, preoperative calcium, and nature of thyroid disease (benign or malignant). On multiple linear regression analysis, preoperative serum calcium was only independent variable significantly associated with development of 24 h post-TT hypocalcemia.

CONCLUSION

Routine pre- and post-TT calcium and Vitamin D supplementation can significantly reduce postoperative hypocalcemia.

Endoscopic thyroidectomy along with bilateral central neck dissection (ETBC) increases the risk of transient hypoparathyroidism for patients with thyroid carcinoma

Increasing number of patients with thyroid carcinoma, especially young female patients, prefer to choose endoscopic thyroidectomy with bilateral central neck dissection (ETBC) for perfect cosmetic effects. However, the incidence of hypoparathyroidism after ETBC has not been well studied. Ninety six patients with papillary thyroid carcinoma were enrolled. All patients, including 49 ETBC and 47 open surgery patients, underwent total thyroidectomy with bilateral central neck dissection (CND). Some patients also underwent lateral neck dissection simultaneously. The incidence of hypoparathyroidism and parathyroid hormone (PTH) level were examined. Patients in the open surgery group had more advanced lesions, with larger tumor (p = 0.000), older age (p = 0.000), and more serious local involvement. The dissection extent of the open group was significantly larger than that of the ETBC group (p = 0.006). In contrast, the ETBC group with less dissection extent showed a significantly higher incidence of transient hypoparathyroidism than the open group (59.2 vs. 29.6 %, p = 0.004). The average PTH decline of the ETBC group was significantly higher than that of the open group on postoperative day 1 (POD1) (32.1 vs. 21.6 pg/ml, p = 0.010). Furthermore, the ETBC group had a significantly higher portion of patients with a PTH <10 pg/ml on POD1 (p = 0.001). One patient in the ETBC group developed permanent hypoparathyroidism. Autotransplantation and inadvertent removal rates of parathyroid did not differ between the two groups. Although generally considered a safe method for patients with thyroid carcinoma, ETBC may increase the risk of transient hypoparathyroidism compared with conventional open surgery.

The feasibility of indocyanine green fluorescence imaging for identifying and assessing the perfusion of parathyroid glands during total thyroidectomy

BACKGROUND

There are limited adjuncts available for identifying and assessing the viability of parathyroid glands (PGs) during total thyroidectomy (TT). The aim of this study is to determine the feasibility of indocyanine green (ICG) imaging in identifying and assessing perfusion of PGs during TT.

METHODS

ICG was administered in patients undergoing TT and fluorescence of PGs was assessed. A grading scale was developed for assessing degree of ICG uptake. Patients were evaluated for hypocalcemia and hypoparathyroidism on post-operative day (POD) #1.

RESULTS

Twenty-seven patients underwent TT with ICG imaging for multinodular goiter (n = 13), thyroid cancer (n = 10), and Graves' disease (n = 4). Eight-five PGs were identified visually, 71 (84%) of which showed ICG fluorescence. False negative rate was 6%. Post-operatively, three patients (11%) had a serum calcium value <8 mg/dl. ICG uptake after TT correlated with post-operative PTH levels: mean POD#1 PTH of those patients with at least two PGs exhibiting <30% fluorescence was 9 pg/ml; whereas those with fewer than two demonstrating <30% fluorescence had a POD#1 PTH of 19.5 pg/ml (P = 0.05).

CONCLUSION

ICG imaging of PGs during TT is feasible. ICG might be a useful adjunct in identifying those patients at risk for post-thyroidectomy hypoparathyroidism. J. Surg. Oncol. 2016;113:775-778. © 2016 Wiley Periodicals, Inc.

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.

Differentiated thyroid cancer: feasibility of loboisthmectomy in an endemic region

AIM

The aim of the present retrospective study was to assess the feasibility of loboisthmectomy for the treatment of differentiated thyroid cancer in a endemic area, evaluating the histopathological features and the results of a case series of 1154 patients.

PATIENTS AND METHODS

The clinical records of 1154 patients submitted to total thyroidectomy in our Department were retrospectively reviewed to analyze the histopathological characters and the results.

RESULTS

In 1044 cases (90.5%) a papillary cancer was observed, in 110 (9.5%) a follicular carcinoma; microcarcinomas were 399 (34.5%). Multifocality was present in 323 cases (28%), in 142 unilateral (12.3%) and in 181 bilateral (15.7%). Thyroiditis coexisted in 472 patients (40.9%), multinodular goiter in 404 (35%), Graves' disease in 48 (4.1%), and multinodular toxic goiter in 38 (3.3%). Complications were: postoperative bleeding in 20 patients (1.7%), transient unilateral vocal cord paralysis in 20 (1.7%) definitive in 10 (0.86%), a transient bilateral paralysis in 1 (0.08%), a transient hypoparathyroidism in 351 (30.4%), and a definitive in 24 (2.07%). Nodal recurrence occurred in 25 patients (2.16%).

CONCLUSIONS

Total thyroidectomy remains the safest treatment in differentiated thyroid cancer, especially if performed in high volume centers in which complications can be minimized. Loboisthmectomy can be a viable and safe alternative in small (< 1 cm) unifocal tumors in patients at low risk. Loboisthmectomy is limited in endemic areas by the association with other thyroid diseases. A correct and detailed information of the patient is essential before planning surgery.

ACTIVE SURVEILLANCE FOR PAPILLARY THYROID MICROCARCINOMA: NEW CHALLENGES AND OPPORTUNITIES FOR THE HEALTH CARE SYSTEM

OBJECTIVE

The dramatic increase in papillary thyroid carcinoma (PTC) is primarily a result of early diagnosis of small cancers. Active surveillance is a promising management strategy for papillary thyroid microcarcinomas (PTMCs). However, as this management strategy gains traction in the U.S., it is imperative that patients and clinicians be properly educated, patients be followed for life, and appropriate tools be identified to implement the strategy.

METHODS

We review previous active surveillance studies and the parameters used to identify patients who are good candidates for active surveillance. We also review some of the challenges to implementing active surveillance protocols in the U.S. and discuss how these might be addressed.

RESULTS

Trials of active surveillance support nonsurgical management as a viable and safe management strategy. However, numerous challenges exist, including the need for adherence to protocols, education of patients and physicians, and awareness of the impact of this strategy on patient psychology and quality of life. The Thyroid Cancer Care Collaborative (TCCC) is a portable record keeping system that can manage a mobile patient population undergoing active surveillance.

CONCLUSION

With proper patient selection, organization, and patient support, active surveillance has the potential to be a long-term management strategy for select patients with PTMC. In order to address the challenges and opportunities for this approach to be successfully implemented in the U.S., it will be necessary to consider psychological and quality of life, cultural differences, and the patient's clinical status.

Thoracic duct lesions in thyroid surgery: An update on diagnosis, treatment and prevention based on a cohort study

INTRODUCTION

Thoracic duct fistula at the cervical level is a severe but rare complication following thyroid surgery, particularly associated to lateral dissection of the neck and to mediastinal goiter.

METHODS

we retrospectively analyzed chylous fistulas observed in a cohort of 13.224 patients underwent surgery for thyroid disease since 1986 to 2014, in the Unit of Endocrine Surgery, S. Maria University Hospital, Terni, Italy.

RESULTS

We observed 20 cases of chylous fistula. Thirteen patients underwent primary surgery in our institution while the remaining 7 cases had been referred to our Department from other hospitals for an already diagnosed lymphatic leak. Surgical procedures carried out included total thyroidectomy for mediastinal goiter in 4 patients, total thyroidectomy for cancer in 2 patients, unilateral functional lymphadenectomy in 11 patients and bilateral in 3. Intraoperative repair was carried out in 4 cases. Of the remaining 16 cases, 4 of the 6 fistulas with low flow leakage healed in about 30 days of conservative treatment, 2 cases instead required surgical repair. All 10 patients with "high-flow" fistula underwent surgery. Despite surgery was performed later, postoperative course in patients with late surgical repair is similar to what observed in those patients with early surgical repair. Both groups underwent cervical drainage removal in post-operative day 4.

CONCLUSION

Healing of a cervical chylous fistula can be achieved by conservative medical therapy (nutritional and pharmacological) but in case of therapeutic failure with rapid decrease of general condition, the surgical approach is necessary. In our experience, duct ligation after unsuccessful conservative treatment, is the only resolutive treatment.

Outpatient thyroid surgery: Safety of an optimized protocol in more than 1,000 patients

OBJECTIVES

Outpatient thyroid surgery is becoming increasingly common. The aim of this study was to clarify the principles for safe outpatient thyroid surgery and review our outcomes with the use of a protocol for outpatient thyroidectomy in a large patient cohort.

STUDY DESIGN

A systematic analysis of a prospectively maintained database of outcomes of thyroidectomy in a tertiary endocrine surgery practice.

SETTING

Academic medical center.

SUBJECTS AND METHODS

A protocol for outpatient thyroidectomy was conceived and refined over 3 years. A prospective analysis of all thyroidectomies accomplished by a single surgeon who used this protocol from May 2006 to November 2013 was then undertaken. Patient demographics, operative and pathologic data, admission status, complications, and readmission rates were recorded.

RESULTS

A total of 1,311 thyroidectomy procedures were performed during the study period, of which 1,026 (78.3 %) were conducted on an outpatient basis. The readmission rate for outpatients was 0.9%, with only 1 readmission in the last 200 procedures. Inpatients (which included patients in the 23-hour "observation" category) were readmitted more often than outpatients (3.5% vs 0.9%, P < .01). Outpatient management increased steadily throughout the study period (from 59.7% to 92.3%, P < .01), despite a larger mean nodule size and a greater rate of malignancy over time. There were no changes in the complication rate across the study timeframe except for the incidence of temporary hypocalcemia, which decreased over time (P < .01).

CONCLUSION

Outpatient thyroid surgery is safe in appropriately selected patients using an optimized and systematic protocol.

The risk of hypocalcemia in patients with parathyroid autotransplantation during thyroidectomy

OBJECTIVE

Thyroidectomy is the most common cause of hypocalcemia. Preservation of parathyroid glands in situ is essential in preventing this complication. The aims of our study were to review patients who underwent parathyroid gland autotransplantation during thyroidectomy, and to compare hypocalcemia rates in patients with and without autotransplantation.

MATERIAL AND METHODS

Parathyroid gland autotransplantation was performed in 43 (7.9%) of 543 patients who underwent thyroidectomy between 2008 and 2012.

RESULTS

Forty-four parathyroid glands were autotransplanted in 43 patients, including 36 women and 7 men. The median age was 55 (range: 30 to 68). The most common cause of autotransplantation was vascular comprise of the parathyroid gland. Early postoperative hypocalcemia developed in 37% of patients with autotransplantation, and none developed permanent hypocalcemia. Transient and permanent hypocalcemia rates were 9.6% and 0.4% in patients without autotransplantation, respectively. The risk of transient hypocalcemia was significantly high in patients with parathyroid autotransplantation (p<0.001). There was no difference between the two groups in terms of permanent hypocalcemia (p=0.156).

CONCLUSION

Despite meticulous dissection, parathyroid glands can be devascularized or removed inadvertently during thyroidectomy. Parathyroid autotransplantation is the best method to maintain parathyroid gland function. Although the risk of transient hypocalcemia is increased following parathyroid autotransplantation, long-term results are satisfactory.

The risk of hypocalcemia in patients with parathyroid autotransplantation during thyroidectomy

OBJECTIVE

Thyroidectomy is the most common cause of hypocalcemia. Preservation of parathyroid glands in situ is essential in preventing this complication. The aims of our study were to review patients who underwent parathyroid gland autotransplantation during thyroidectomy, and to compare hypocalcemia rates in patients with and without autotransplantation.

MATERIAL AND METHODS

Parathyroid gland autotransplantation was performed in 43 (7.9%) of 543 patients who underwent thyroidectomy between 2008 and 2012.

RESULTS

Forty-four parathyroid glands were autotransplanted in 43 patients, including 36 women and 7 men. The median age was 55 (range: 30 to 68). The most common cause of autotransplantation was vascular comprise of the parathyroid gland. Early postoperative hypocalcemia developed in 37% of patients with autotransplantation, and none developed permanent hypocalcemia. Transient and permanent hypocalcemia rates were 9.6% and 0.4% in patients without autotransplantation, respectively. The risk of transient hypocalcemia was significantly high in patients with parathyroid autotransplantation (p<0.001). There was no difference between the two groups in terms of permanent hypocalcemia (p=0.156).

CONCLUSION

Despite meticulous dissection, parathyroid glands can be devascularized or removed inadvertently during thyroidectomy. Parathyroid autotransplantation is the best method to maintain parathyroid gland function. Although the risk of transient hypocalcemia is increased following parathyroid autotransplantation, long-term results are satisfactory.

Surgical morbidity of cervical lymphadenectomy for thyroid cancer: A retrospective cohort study over 25 years

INTRODUCTION

Prognosis of thyroid cancer is strictly related to loco-regional metastases. Cervical lymphadenectomy has a specific oncologic role but may lead to significant increase of morbidity. Aim of the study is the analysis of surgical morbidity in cervical lymphadenectomy for thyroid cancer.

METHODS

We retrospectively analyzed 1.765 thyroid cancers operated over a period of 25 years at S. Maria University Hospital, Terni, University of Perugia, Italy. Type of lymphadenectomy, histology and complications were analysed.

RESULTS

A prevalence of differentiated and medullary cancers was observed (respectively 88% and 7.2%). Central lymphadenectomy was carried out in 425 patients, lateral modified and radical lymphadenectomy respectively in 651 and 17 cases. Following central neck dissection we observed: bilateral and unilateral temporary recurrent nerves palsy respectively of 0.7% and 3.5%, unilateral permanent palsy in 1.6% of cases, temporary and permanent hypoparathyroidism respectively in 17.6% and 4.4%. After lateral neck dissection we observed: intra and post-operative haemorrhage respectively in 2% and 0.29%, respiratory distress in 0.29%, lesions of facial nerve in 0.44%, of vagus in 0.14%, of phrenic nerve in 0.14%, of hypoglossal nerve in 0.29%, of the accessory nerve, transient in 1.34% and permanent in 0.29%, permanent lesion of cervical plexus in 0.29%, salivary fistula in 0.14% and chylous fistula in 1.04% of patients. Student's t test was used to compare groups when appliable.

CONCLUSION

Central and lateral cervical lymph node dissection are associated to severe morbidity. Correct indication, surgical expertise, high volume of patients and early multidisciplinary management of complications is the key of an acceptable balance between oncologic benefits and surgical morbidity.

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.

Efficacy and Safety of Radiofrequency Ablation Versus Observation for Nonfunctioning Benign Thyroid Nodules: A Randomized Controlled International Collaborative Trial

BACKGROUND

Percutaneous radiofrequency thermal ablation (RFA) has been reported as an effective tool for the management of benign thyroid nodules (BTN). However, large, randomized controlled trials (RCTs) are lacking.

OBJECTIVE

The aims of this study were to assess the volume reduction of BTN after a single RFA performed using the moving-shot technique and to compare the volume reduction obtained in patients treated in two centers with different experience of the moving-shot technique.

METHOD

This study was an international prospective RCT. It was carried out at the Mauriziano Hospital (Turin, Italy) and the Asan Medical Center (Seoul, Korea). Eighty patients harboring solid, compressive, nonfunctioning BTN (volume 10-20 mL) were enrolled. Twenty patients in each country were treated by RFA using a 18-Gauge internally cooled electrode (group A); 20 nontreated patients in each country were followed as controls (group B).

RESULTS

At six months, BTN volume significantly decreased in group A (15.1±3.1 mL vs. 4.2±2.7 mL; p<0.0001), whereas it remained unchanged in group B (14.4±3.3 mL vs. 15.2±3.5 mL). The baseline volume was larger in the Italian series (16.4±2.5 mL vs. 13.9±3.3 mL, p=0.009). However, at six months, there was no significant difference between the Korean group and the Italian group (3.7±2.9 mL vs. 5.5±2.2 mL). Both cosmetic and compressive symptoms significantly improved (3.6±0.5 vs. 1.7±0.4 and 3.6±1.9 vs. 0.4±0.7, respectively; p<0.001). No side effects occurred.

CONCLUSIONS

RFA was effective in reducing the volume of BTN. The outcome was similar in centers with different experience in the moving-shot technique.

Perioperative kinetics of parathyroid hormone in unilateral, primary thyroid surgery

Dysfunction of the parathyroid glands is an important cause of complications after thyroid surgery. Intraoperative monitoring of the function of the parathyroid glands can be performed using parathyroid hormone (PTH) kinetics. Unilateral thyroid surgery is associated with a decreased risk for postoperative hypocalcemia (POH) and permanent hypoparathyroidism (PEH). We focused on unilateral thyroid surgery by monitoring the functionality of the parathyroid glands and comparing the perioperative PTH kinetics of patients with and without POH. In a prospective study, 143 patients scheduled for unilateral thyroid surgery underwent monitoring of perioperative changes in serum PTH and serum calcium levels, and of clinical symptoms of hypocalcemia. The rates of POH and PEH were 18.2 and 0%, respectively. In patients without POH, PTH significantly increased from the time of skin incision to the end of the operation and after the operation (20.1 pg/ml, IQR 15.5-26.8 vs. 21.4 pg/ml, IQR 16.4-29.5; p=0.005), which was not the case in patients who developed POH. In a multivariate analysis of predictive factors for POH, two parameters became significant, namely female gender (odds ratio 6.87, 95% confidence interval 0.92-51.01) and lower initial serum calcium levels (odds ratio 3.54*e(-8), 95% confidence interval 3.63*e(-12); 0.00). The rate of POH was unexpectedly high. Rather than intraoperative PTH declines, an unstable balance of factors that influence calcium metabolism likely is the major contributor to POH after unilateral thyroid surgery. There was no case of PEH after unilateral, primary thyroid surgery, which underlines the need for an individualized approach to the extent of resection.