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

Phase-sensitive fluorescence detector for parathyroid glands during thyroidectomy: A preliminary report

Despite advances in medical technology, the parathyroid glands are still damaged during thyroid surgery. Our previous studies exploring methods for locating the parathyroid glands using autofluorescence have limitations, such as turning off the surgical light or requiring additional matching between the autofluorescence image and real-surgical field-of-view. We developed a probe-type parathyroid autofluorescence detector using a phase-sensitive process and optical filtering to overcome these limitations. A preliminary clinical trial was performed on eight parathyroid glands in four patients. The normalized mean signal of the normal parathyroid glands was 332% stronger than that of the thyroid, and 384%, 459% and 286% stronger than the signal of the muscle, trachea and fat, respectively. Additionally, the device also detected fluorescence from indocyanine green.

Systematic Review of Recurrence Rate after Hemithyroidectomy for Low-Risk Well-Differentiated Thyroid Cancer

BACKGROUND

Surgical extent in the management of well-differentiated thyroid cancer (DTC) remains a recurrent subject of debate. This is especially relevant in low-risk DTC of 1-4 cm, which represent the majority of new thyroid cancer diagnoses. With trends towards treatment de-escalation and recent guidelines from the American Thyroid Association and British Thyroid Association endorsing hemithyroidectomy (HT) alone for low-risk DTC of 1-4 cm, we sought to systematically appraise the literature to examine recurrence rate outcomes after HT in this low-risk group.

SUMMARY

Searching PubMed, Cochrane Library, and Ovid MEDLINE, we conducted a systematic review to assess the survival and recurrence rate data presented in all published studies that had a cohort of patients treated with HT for the treatment of DTC. Pooled 10-year survival and recurrence rates, odds ratios, and 95% confidence intervals were calculated for meta-analysis. We identified 31 studies (with a total of 228,746 patients (HT: 36,129, total thyroidectomy, TT: 192,617), which had published recurrence and/or survival data for patients having had HT for DTC. We discovered a pooled recurrence rate of 9.0% for HT, which is significantly higher than in previously published reports. Further, this rate is maintained when examining patients within low-risk cohorts established with recognised risk classifications. We also discovered that of those patients who develop recurrent disease, 48% recur outside the central neck.

KEY MESSAGES

Our study provides a comprehensive systematic review of evidence aimed primarily at defining the recurrence rate in DTC after HT, and more specifically within the low-risk subgroup. We describe pooled recurrence and 10-year survival rates from a larger, broader, and more contemporary patient population than has been previously reported. Our findings indicate that there is a small but significantly higher recurrence rate after HT than TT, but the evidence base is heterogenous and subject to confounding factors and would ultimately benefit from prospective randomised trials to overcome these deficiencies.

Near-infrared auto-fluorescence spectroscopy combining with Fisher's linear discriminant analysis improves intraoperative real-time identification of normal parathyroid in thyroidectomy

BACKGROUND

To evaluate the efficacy of a sensitive, real-time tool for identification and protection for parathyroid glands during thyroidectomy.

METHODS

Near-infrared (NIR) auto-fluorescence was measured intraoperatively from 20 patients undergoing thyroidectomy. Spectra were measured from suspicious parathyroid glands and surrounding neck tissues during the operation with a NIR fluorescence system. Fast frozen sections were performed on the suspicious parathyroid glands. Accuracy was evaluated by comparison with histology and NIR identification. Data were attracted for Fisher's linear discriminant analysis.

RESULTS

The auto-fluorescence intensity of parathyroid was significantly higher than that of thyroid, fat and lymph node. The peak intensity of auto-fluorescence from parathyroid was 5.55 times of that from thyroid at the corresponding wave number. Of the 20 patients, the parathyroid was accurately detected and identified in 19 patients by NIR system, compared with their histologic results. One suspicious parathyroid did not exhibit typical spectra, and was proved to be fat tissue by histology. The NIR auto-fluorescence method had a 100% sensitivity of parathyroid glands identification and a high accuracy of 95%. The positive predictive value was 95%. The parathyroid gland have specific auto-fluorescence spectrum and can be separated from the other three samples through the Fisher's linear discriminant analysis.

CONCLUSIONS

NIR auto-fluorescence spectroscopy can accurately identify normal parathyroid gland during thyroidectomy. The Fisher's linear discriminant analysis demonstrated the specificity of the NIR auto-fluorescence of parathyroid tissue and its efficacy in parathyroid discrimination.

5P Strategies for Management of Multiple Endocrine Neoplasia Type 2: A Paradigm of Precision Medicine

Multiple endocrine neoplasia type 2 (MEN2) is a neuroendocrine cancer syndrome characterized by medullary thyroid carcinoma, in combination or not with pheochromocytoma, hyperparathyroidism, and extra-endocrine features. MEN2 syndrome includes two clinically distinct forms subtyped as MEN2A and MEN2B. Nearly all MEN2 cases are caused by germline mutations of the RET proto-oncogene. In this review, we propose "5P" strategies for management of MEN2: prevention, prediction, personalization, psychological support, and participation, which could effectively improve clinical outcomes of patients. Based on RET mutations, MEN2 could be prevented through prenatal diagnosis or preimplantation genetic testing. Identification of pathogenic mutations in RET can enable early diagnosis of MEN2. Combining RET mutation testing with measurement of serum calcitonin, plasma or urinary metanephrine/normetanephrine, and serum parathyroid hormone levels could allow risk stratification and accurately prediction of MEN2 progression, thus facilitating implementation of personalized precision treatments to increase disease-free survival and overall survival. Furthermore, increased awareness of MEN2 is needed, which requires participation of physicians, patients, family members, and related organizations. Psychological support is also important for patients with MEN2 to promote comprehensive management of MEN2 symptoms. The "5P" strategies for management of MEN2 represent a typical clinical example of precision medicine. These strategies could effectively improve the health of MEN2 patient, and avoid adverse outcomes, including death and major morbidity, from MEN2.

Differentiation of Rat Adipose-Derived Stem Cells into Parathyroid-Like Cells

BACKGROUND

The current treatment for postoperative hypoparathyroidism has shortcomings, such as repeated blood monitoring for dosage adjustment, uncertain long-term efficacy, and the high price of recombinant parathyroid hormone therapy. Adipose-derived stem cells can undergo adipogenic and osteogenic differentiation in vitro and are considered a novel source of parathyroid-like cells, but the idea lacks theoretical basis and feasibility. We aimed at establishing a protocol for differentiating adipose-derived stem cells into parathyroid-like cells for treating hypoparathyroidism.

MATERIALS

/.

METHODS

Adipose-derived stem cells were isolated and purified from the inguinal adipose tissue of Sprague Dawley rats. Adipogenic differentiation and osteogenic differentiation of the cells were identified by oil red O and alizarin red S staining, respectively. The adipose-derived stem cells were stimulated by sonic hedgehog (SHH) and activin A. The differentiation of the adipose-derived stem cells to parathyroid-like cells was confirmed by the detection of parathyroid hormone and the related parathyroid markers.

RESULTS

Adipose-derived stem cells were successfully isolated and purified from the rat adipocytes. The adipogenic and osteogenic differentiation capabilities of the adipose-derived stem cells were determined. SHH and activin A stimulated parathyroid hormone secretion by the adipose-derived stem cells and significantly increased the expression of calcium-sensing receptor (CaSR), parathyroid hormone, and glial cells missing homolog 2 (GCM2) in the cells in a time- and concentration-dependent manner.

CONCLUSION

We successfully differentiated rat adipose-derived stem cells into parathyroid-like cells, which will pave a new route to curing hypoparathyroidism.

Parathyroid Hormone Reduction Predicts Transient Hypocalcemia after Total Thyroidectomy: A Single-Center Prospective Study

OBJECTIVE

We performed this study to investigate the risk factors for postoperative hypocalcemia after total thyroidectomy with central lymph node dissection (CLND). Study Design. This was a single-center prospective study based on 176 consecutive patients who underwent total thyroidectomy for papillary thyroid carcinoma. Setting. Patients were recruited between January 2016 and June 2018. Subjects and Methods. Patients who underwent bilateral (n = 155, bilateral group) and ipsilateral CLND (n = 21) after total thyroidectomy were included. The preoperative and postoperative parathyroid hormone (PTH) and calcium levels were detected. The risk factors for transient hypocalcemia were identified using logistic regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifty-one (28.98%) patients developed transient hypocalcemia, and 2 patients (1.14%) developed permanent hypoparathyroidism. There was no difference in the gender ratio or the morbidity of hypocalcemia between the patients who underwent bilateral and ipsilateral CLND. On postoperative day 1, PTH decrease was a risk factor for transient hypocalcemia in the whole cohort (β = 0.043, OR = 1.044, 95% CI 1.023-1.065, p < 0.001), bilateral group (β = 0.042, OR = 1.043, 95% CI 1.022-1.064, p < 0.001), and female patients (β = 0.049, OR = 1.050, 95% CI 1.026-1.075, p < 0.001). Tumor diameter was a risk factor for transient hypocalcemia in female patients (β = 0.499, OR = 1.647, 95% CI 1.003-2.704, p=0.049). The ROC curve analysis illustrated that 65.58%, 71.00%, and 71.00% PTH level reduction had high accuracy in predicting transient hypocalcemia in the whole cohort, bilateral group, and female patients, respectively (AUC = 0.986, 0.987, and 0.987).

CONCLUSION

Asymptomatic female patients with bilateral CLND and a 71.00% PTH level reduction were at a high risk of transient hypocalcemia.

Vitamin D Deficiency as a Predictive Factor of Transient Hypocalcemia after Total Thyroidectomy

BACKGROUND

Total thyroidectomy (TT) is recommended in the treatment of malignant and benignant thyroid diseases, and, to date, transient hypocalcemia is the most frequent complication after the procedure. We prospectively evaluated the role of vitamin D deficiency as a predictor of postoperative hypocalcemia.

METHODS

This is a prospective cohort study which was conducted between January 2016 and April 2019. A total of 177 consecutive patients (141 (79.7%) women and 36 (20.3%) men) who underwent TT were included in the current study. Hypocalcemia occurred when serum calcium levels were below 8.0 mg/dL or 1.10 mmol/L. Patients were divided into two groups (Group 1, normocalcemic; Group 2, hypocalcemic) and were assessed taking into consideration preoperative serum 25-hydroxy vitamin D (25-OHD) levels, preoperative serum calcium levels, thyroid hormone levels, sex, body mass index (BMI), and smoking habits. Vitamin D deficiency was defined as 25-OHD levels <25 ng/mL.

RESULTS

The incidence of postoperative asymptomatic and symptomatic hypocalcemia in the two groups was 19.8% and 15.8%, respectively. Preoperative 25-OHD level was significantly different between Group 1 and Group 2 (31.5 ± 15.0 ng/mL vs 18.7 ± 9.8 ng/mL,p=0.017). Logistic regression analysis revealed that preoperative vitamin D deficiency was a significant predictive factor of postoperative hypocalcemia (p=0.012), and, specifically, the risk of hypocalcemia increased 15-fold in patients with a preoperative vitamin D level <25 ng/mL (odds ratio [OR], 14.8).

CONCLUSIONS

Postoperative hypocalcemia is significantly associated with low preoperative levels of serum 25-OHD. Our studies demonstrate that vitamin D deficiency (<25 ng/mL) is an independent predictive factor of postoperative hypocalcemia.

Effect of Preoperative Vitamin D Deficiency on Hypocalcemia in Patients with Acute Hypoparathyroidism after Thyroidectomy

Postoperative hypoparathyroidism is a common complication of total or completion thyroidectomy. The association between preoperative vitamin D deficiency (VDD) and the development of more severe postoperative hypocalcemia is still unclear. Objectives. To evaluate the effect of preoperative VDD on severity of hypocalcemia in patients with hypoparathyroidism following thyroidectomy. Methods. Patients who developed acute hypoparathyroidism after total or completion thyroidectomy, defined as postoperative parathyroid hormone (PTH) level <15 pg/mL and albumin-adjusted calcium level <8.6 mg/dL, were prospectively recruited. Patients were divided into two groups according to their preoperative vitamin D status (VDD group: 25-hydroxyvitamin D (25(OH)D) level <20 ng/mL; non-VDD group: 25(OH) level ≥20 ng/mL). The primary outcome was severity of hypocalcemia in postoperative hypoparathyroidism. Significant hypocalcemia was defined as calcium level ≤7.5 mg/dL. Results. Forty-three patients (21 VDD, 22 non-VDD) were enrolled. Serum total albumin-adjusted calcium level was significantly lower in the VDD group (7.71 ± 0.5 vs. 8.16 ± 0.4 mg/dL, p < 0.01), and the incidence of symptomatic hypocalcemia was significantly higher in the VDD group (43% vs. 9%, p=0.01). The median maximal daily supplementary dose of elemental calcium was significantly higher in the VDD group (2,400 vs. 1,500 mg/day, p=0.02). Length of hospital stay was nonsignificantly longer in the VDD group (p=0.06). Preoperative vitamin D level <19.6 ng/mL could predict significant and symptomatic hypocalcemia in postoperative hypoparathyroidism with sensitivity of 90% and 82% and specificity of 70% and 69%, respectively. Conclusion. VDD is an independent risk factor for both significant and symptomatic hypocalcemia in hypoparathyroidism patients after thyroid surgery.

Risk Factors of Incidental Parathyroidecomy in Thyroid Surgery

Background: Incidental parathyroidectomy with subsequent hypoparathyroidism and postoperative hypocalcemia is thought to be one of the common complications of thyroidectomy. Current literature reports wide discrepancy in incidence and risk factors.

Objectives: The aim of our study was to evaluate the incidence and risk factors of incidental parathyroidectomy in thyroid surgery.

Methods: A retrospective study included 270 patients who had thyroid surgery that was performed over two years from January 2017 to December 2018 in two tertiary care hospitals. Preoperative and postoperative records were assessed. Factors such as gender, diagnosis, type of surgery, and usage of surgical loupes during the procedure were evaluated and were compared to find the association with incidental parathyroidectomy in thyroid surgery.

Results: Incidental parathyroidectomy was noticed in 62 (23%) surgical specimens during histopathologic examination. There was no significant association between incidental parathyroidectomy and sex of patient, use of surgical loupes, pathology of thyroid disease, or neck dissection.

Conclusion: Although the risk of incidental parathyroidectomy is inevitable, careful dissection and meticulous intraoperative identification of parathyroid gland during thyroidectomy can reduce the incidence of incidental parathyroidectomy, thereby minimizing the risk of postoperative hypoparathyroidism and hypocalcemia.

Severe Hypocalcemia After Thyroidectomy: An Analysis of 7366 Patients

OBJECTIVE

The aim of the study was to determine severe hypocalcemia rate following thyroidectomy and factors associated with its occurrence.

BACKGROUND

Hypocalcemia is the most common complication after thyroidectomy. Severe post-thyroidectomy hypocalcemia can be life-threatening; data on this specific complication are scarce.

METHODS

Patients who underwent thyroidectomy in the American College of Surgeons-National Surgical Quality Improvement Program thyroidectomy-targeted database (2016-2017) were abstracted. A severe hypocalcemic event was defined as hypocalcemia requiring intravenous calcium, emergent clinic/hospital visit, or a readmission for hypocalcemia. Multivariable regression was used to identify factors independently associated with occurrence of severe hypocalcemia.

RESULTS

Severe hypocalcemia occurred in 5.8% (n = 428) of 7366 thyroidectomy patients, with 83.2% necessitating intravenous calcium treatment. Rate of severe hypocalcemia varied by diagnosis and procedure (0.5% for subtotal thyroidectomy to 12.5% for thyroidectomy involving neck dissections). Overall, 38.3% of severe hypocalcemic events occurred after discharge; in this subset, 59.1% experienced severe hypocalcemia despite being discharged with calcium and vitamin D. Severe hypocalcemia patients had higher rates of recurrent laryngeal nerve injury (13.4% vs 6.6%), unplanned reoperations (4.4% vs 1.3%), and longer hospital stay (30.4% vs 6.2% ≥3 days (all P < 0.01). After multivariate adjustment, severe hypocalcemia was associated with multiple factors including Graves disease [odds ratio (OR) = 2.06], lateral neck dissections (OR: 3.10), and unexpected reoperations (OR = 3.55); all P values less than 0.01.

CONCLUSIONS

Severe hypocalcemia and suboptimal hypocalcemia management after thyroidectomy are common. Patients who experienced severe hypocalcemia had higher rates of nerve injury and unexpected reoperations, indicating surgical complexity and provider inexperience. More biochemical surveillance particularly a parathyroid hormone-based protocol, fine-tuned supplementation, and selective referral could reduce occurrence of this morbid complication.

Rate of drop in serum calcium as a predictor of hypocalcemic symptoms post total thyroidectomy

The rate of drop in serum calcium post total thyroidectomy is a predictor of hypocalcemic symptoms in adults, after adjusting for other significant covariates.

INTRODUCTION

Test the hypothesis that rate of drop in calcium is a significant and independent predictor of post-operative hypocalcemic symptoms post total thyroidectomy.

METHODS

A retrospective chart review (electronic and hard copy) for 429 patients who underwent total thyroidectomy from January 2011 to December 2016. We collected information on demographics, clinical characteristics, information on surgical intervention, histopathology reports, clinical course, biochemistries, treatments and discharge instructions.

RESULTS

Sixty-one patients (14%) developed post-operative hypocalcemic symptoms. The rate of calcium drop, younger age, female gender, and lower body mass index, and the presence of parathyroid tissue in resected specimen all correlated significantly with the development of symptoms. The rate of drop in serum calcium and the post-operative serum calcium level remained the only significant predictors of symptom development, after adjustment for other significant co-variates. Using a receiver operating characteristics curve, a cutoff rate of calcium drop > 0.083 mg/dl/h, that is 1 mg/dl over 12 h, has a sensitivity of 71% and specificity of 73% for detecting hypocalcemic symptoms.

CONCLUSION

The rate of drop of serum calcium post total thyroidectomy significantly and independently correlated with the development of hypocalcemic symptoms. Patients with a rate of drop < 1 mg/dl/12 h may be considered for earlier discharge and less aggressive management peri-operatively.

Surgical Complications After Thyroid Surgery: A 10-Year Experience at Jeddah, Saudi Arabia

To evaluate the incidence and predictive risk factors of complications in patients who underwent thyroid surgery at our hospital with a residency training program. This retrospective cohort study analyzed the complications in all patients who underwent thyroid surgery between January 2008 and December 2017. Demographic data, preoperative diagnosis based on fine needle aspiration cytology, surgical approach, permanent pathology, postoperative complications, and factors associated with complications were recorded. At our hospital, 456 patients underwent thyroidectomy. The most common surgical complications were asymptomatic biochemical hypocalcemia and symptomatic hypocalcemia in 109 (23.9%) and 50 (11%) patients, respectively. Other surgical complications included permanent hypocalcemia, transient vocal cord palsy, permanent vocal cord palsy, hematoma, seroma, chyle fistula, and Horner's syndrome. Mean age > 45 years and more extensive surgery were significantly associated with overall complications (P = 0.003; < 0.001). Mean age > 50 years and vitamin D level < 25 nmol/L (< 10 ng/mL) were significantly associated with hypocalcemia (P = 0.008; < 0.001). Moreover, the extent of surgery and advanced thyroid carcinoma were significantly associated with vocal cord palsy (P < 0.001; 0.05). Hypocalcemia and vocal cord palsy are the most significant complications. Thyroid surgery can be performed safely by senior residents in the residency training program under the direct supervision of an experienced surgeon.

Evaluation of Parathyroid Glands with Indocyanine Green Fluorescence Angiography After Thyroidectomy

BACKGROUND

Indocyanine green fluorescence angiography (ICGA) is a new adjunct that has been used in surgical procedures to assess blood flow. This study evaluated the utility of ICGA compared to visual inspection to predict parathyroid function, guide autotransplantation and potentially decrease permanent hypoparathyroidism.

METHODS

This was a retrospective study of patients who underwent total or near-total thyroidectomy (T-NT) between January 2015 and March 2018. Patients with preoperative hyperparathyroidism and those undergoing reoperation were excluded. Patients who had ICGA were compared to T-NT patients without ICGA. Data were analyzed to assess the frequency of autotransplantation and incidence of hypoparathyroidism between groups.

RESULTS

In total, 210 patients underwent T-NT: 86 with ICGA and 124 without. Autotransplantation was more common in the ICGA group at 36% compared to 12% in the control (p = 0.0001). There was no correlation with at least one normal parathyroid gland on ICGA and postoperative PTH levels (p = 0.75). There was a difference in having normal postoperative PTH when there were at least two normal parathyroid glands (n = 50) compared to patients with less than two normal ICGA glands (n = 36, p = 0.044). Visual assessment and ICGA assessment of vascularity were in agreement, 245/281 (87%). There were 19 glands (6.8%) that would have undergone autotransplant based on visual inspection that had adequate blood supply on ICGA. Transient hypoparathyroidism was present in 45 out of 124 controls (36%) and 32 out of 86 (37%) in the ICG group.

CONCLUSIONS

ICGA is a novel technique that may improve the assessment of parathyroid gland blood supply compared to visual inspection. ICGA can guide more appropriate autotransplantation without compromising postoperative parathyroid function. At least two vascularized glands on ICGA may predict postoperative parathyroid gland function.

Hypoparathyroidism After Total Thyroidectomy: Importance of the Intraoperative Management of the Parathyroid Glands

BACKGROUND

Total thyroidectomy is the most common surgical procedure for the treatment of thyroid diseases. Postoperative hypocalcemia/hypoparathyroidism is the most frequent complication after total thyroidectomy. The aim of this study was to evaluate the rate of postoperative hypocalcemia and permanent hypoparathyroidism after total thyroidectomy in order to identify potential risk factors and to evaluate the impact of parathyroid autotransplantation.

PATIENTS AND METHODS

We performed a retrospective analysis of 1018 patients who underwent total thyroidectomy at our institution between 2000 and 2016. Medical records were reviewed to analyze patient features, clinical presentation, management and postoperative complications. Descriptive and inferential statistics were employed based on the natural scaling of each included variable. Statistical significance was set at p ≤ 0.05.

RESULTS

Mean ± SD age was 46.79 ± 15.9 years; 112 (11.7%) were males and 844 (88.3%) females. A total of 642 (67.2%) patients underwent surgery for malignant disease. The rate of postoperative hypocalcemia, transient, protracted and permanent hypoparathyroidism was 32.8%, 14.43%, 18.4% and 3.9%, respectively. Permanent hypoparathyroidism was significantly associated with the number of parathyroid glands remaining in situ (4 glands: 2.5%, 3 glands: 3.8%, 1-2 glands: 13.3%; p ˂ 0.0001) [OR for 1-2 glands in situ = 5.32, CI 95% 2.61-10.82]. Other risk factors related to permanent hypoparathyroidism were obesity (OR 3.56, CI 95% 1.79-7.07), concomitant level VI lymph node dissection (OR 3.04, CI 95% 1.46-6.37) and incidental parathyroidectomy without autotransplantation (OR 3.6, CI 95% 1.85-7.02).

CONCLUSIONS

Identification and in situ preservation of at least three parathyroid glands were associated with a lower rate of postoperative hypocalcemia (30.4%) and permanent postoperative hypoparathyroidism (2.79%).

Hypercalcemic Crisis in a Patient with Post-Surgical Hypoparathyroidism

Calcium alkali syndrome (CAS), a relatively unusual etiology of hypercalcemia, is characterized by a classical triad of hypercalcemia, azotemia, and metabolic alkalosis. This condition has been described in patients who have taken an excess dose of calcium with an alkali or with a volume-depletion status. To diagnose CAS it requires a high index of suspicion and a detailed history of medication/supplement intake specifically for calcium-containing drugs and a history of all possible ingested alkali. We reported a case of post-surgical hypoparathyroidism whom later on was presented with hypercalcemic crisis due to CAS. The proposed mechanism of CAS and management are also included.

Morbidity following thyroid surgery: acceptable rates and how to manage complicated patients

PURPOSE

The endocrine surgeon and the endocrinologist should standardize how they deal with patients with an indication for thyroidectomy, as the road to surgery starts well before the operation itself. The patient should be thoroughly informed about where and how surgery will be performed, the postoperative improvements that can be expected, and the possibility and incidence of relevant complications. This short review aims at identifying the most common postoperative issues after thyroidectomy, with the relevant therapeutic suggestions.

METHODS

A revision of studies reporting the morbidity of thyroid surgery, involving the largest numbers of patients.

RESULTS

It has been clearly demonstrated that the outcome of thyroid surgery is significantly better when the procedure is performed by an experienced surgeon. Thus, the number of thyroidectomies performed by a surgeon should drive the endocrinologist when referring a patient.

CONCLUSIONS

Despite the surgeon's experience, thyroidectomy is burdened by a relatively high rate of postoperative issues ranging from less severe ones to others causing significant changes in the patient's quality of life. Minor, non-invalidating symptoms have been described in 40% of patients after thyroidectomy (e.g. hoarseness, mild dysphagia, some degree of voice alteration); however, these symptoms usually resolve within a few months of surgery, with or without early treatment. On the other hand, major postoperative complications are observed in a limited number of patients, but in these cases early diagnosis is important to provide the most appropriate postoperative treatment, and thus hasten full recovery or at least achieve the greatest possible improvement.

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.

Risk Factors of Incidental Parathyroidectomy and its Relationship with Hypocalcemia after Thyroidectomy: A Retrospective Study

Background: The aim of this study was to determine the incidence of incidental parathyroidectomy, the relationship between incidental parathyroidectomy and postoperative hypocalcemia, and risk factors for incidental parathyroidectomy in patients undergoing thyroid surgery.

Methods: The study was conducted by analyzing the records of patients who underwent thyroid surgery in a tertiary university hospital between January 2012 and December 2017 retrospectively. The risk factors of postoperative hypocalcemia were determined by comparing postoperative Ca values with age, sex, preoperative Ca value, dominant nodule diameter, type of surgery, and histopathological examination of the thyroidectomy material. According to the final pathology results, the patients were divided into two groups - the ones with and without incidental parathyroidectomy. The risk factors for incidental parathyroidectomy were determined by comparing the two groups in terms of age, sex, dominant nodule diameter, type of surgery, and histopathological results (malign/benign).

Results: When the risk factors of postoperative hypocalcemia were examined, female gender, age <28.5 years old, low level of preoperative mean Ca value, and total thyroidectomy were found to be critical risk factors (p<0.05). When the risk factors of incidental parathyroidectomy were examined, total thyroidectomy and thyroid malignancy were found to be important risk factors (p<0.05).

Conclusion: Female gender, age<28.5 years old, low level of preoperative Ca value, and total thyroidectomy were associated with postoperative hypocalcemia, but no relationship was found between incidental parathyroidectomy and postoperative hypocalcemia.

Possible role of low magnesium levels in the onset of postoperative hypoparathyroidism following thyroidectomy

BACKGROUND

A positive correlation between calcium and magnesium serum levels is well known and depends upon various factors. This study aims at verifying the existence of this association in a retrospective series of patients who underwent thyroid surgery.

METHODS

Two hundred and eighty-five consecutive patients (202 female, 83 male, mean age 57 years) who underwent at least total thyroidectomy (TT) and had a complete clinical and biochemical pre- and postoperative evaluation were included in the study. Patients were evaluated with regard to: sex, age, indications for surgery, operative time, number of accidentally removed parathyroids, extent and time of surgery, thyroiditis, final histology, pre- and postoperative levels of calcium, magnesium, vitamin D, and creatinine, presence of symptoms of hypocalcemia. Statistical analysis was performed using the R software.

RESULTS

In the postoperative period, biochemical hypocalcemia (<8.5 mg/dL) was observed in 126 patients (44%) and severe hypocalcemia (<7.5 mg/dL, a level indicating the need for longer hospitalization) was seen in 40 (14%). When analyzing patients with and without postoperative hypocalcemia, the factors affecting postoperative biochemical hypocalcemia were: older age (P=0.019), longer operative time (P=0.039), and a highly significant correlation between postoperative calcium and magnesium levels (r=0.432; P<0.001).

CONCLUSIONS

The only factor among the ones we analyzed in this retrospective study that would appear to be linked to the onset of clinically relevant hypocalcemia is low magnesium levels in the postoperative period. A prospective randomized study with a group of patients undergoing magnesium replacement in the postoperative period can clarify the possible role of magnesium repletion on hypocalcemia.

New Advances of ICG Angiography in Parathyroid Identification

Objective:

For surgeons, locating parathyroid in thyroidectomy and parathyroidectomy is critical since parathyroid plays an important role in calcium balance. The fluorescence of parathyroid has already been found by researchers and the angiography equipment detecting the fluorescence of parathyroid with indocyanine green has been widely applied. Using the indocyanine green angiography and looking at the actual fluorescence of in vivo and in vitro tissues, it was possible to identify thyroid, parathyroid, lymph nodes and fat tissues during the surgical procedure. This mini-review aims to present the application of indocyanine green angiography in parathyroid detection and discusses the safety of this method.

Methods:

The relevant data were searched by using the keywords “Indocyanine green,” “Parathyroid,” and “Identification” and “Protection” in “Pubmed,” “Web of Science” and “China Knowledge Resource Integrated databases”, and a manual search was done to acquire peer-reviewed articles and reports about indocyanine green.

Results:

Indocyanine green dye along with the intraoperative fluorescence imaging system is safe in detecting parathyroid and predicting postoperative hypoparathyroidism.

Conclusion:

The conclusion suggests that indocyanine green angiography is a safe, effective and easy way to detect parathyroid glands. The conclusion will be of interest to surgeons regarding thyroidectomy and parathyroidectomy.

Hungry bone syndrome after thyroidectomy for thyroid storm

A 39-year-old man was admitted to our hospital with the diagnosis of thyroid storm due to Graves' disease. Near-total thyroidectomy was performed after 1 month's pharmacological treatment, and he presented with tetany next morning. Serum corrected calcium value was 5.7 mg/dL. Procollagen type 1 N-terminal propeptide increased considerably, while tartrate-resistant acid phosphatase 5b decreased. These changes indicated that bone formation exceeded bone resorption in reverse after thyroidectomy. Calcium gluconate was administered intravenously for 14 days, before the patient was discharged. Oral administration of calcium and active forms of vitamin D was continued for 4 months. Rapid skeletal uptake of calcium from blood caused severe and persistent hypocalcaemia, which is called hungry bone syndrome. When patients with Graves' disease have severe thyrotoxicosis, high serum alkaline phosphatase levels and low bone mineral densities, they are at high risk for hungry bone syndrome after thyroidectomy, and should be educated for the symptoms of hypocalcaemia.

The utility of intact parathyroid hormone level in managing hypocalcemia after thyroidectomy in children

INTRODUCTION

Hypocalcemia is a common complication after thyroidectomy. Intact parathyroid hormone (PTH) has been successfully used as a predictive indicator for hypocalcemia in adults during the postoperative period. We aim to demonstrate the utility of PTH in predicting and managing postoperative hypocalcemia following thyroidectomy in pediatrics.

METHODS

The study is a retrospective case series including 38 patients up to 18 years of age who underwent total or completion thyroidectomy from 1/1/2010 to 12/31/2016 at a tertiary pediatric academic center. Patient demographics, pathology, postoperative PTH, serum calcium, and length of stay were analyzed.

RESULTS

The median age was 14.3 years (range of 4.3-18.4 years) with 84.2% being female. Thyroid malignancy was noted in 25 patients, and 13 had benign pathology including 8 patients with multinodular goiter and 5 with Grave's disease. In this serie, 63.2% (24/38) developed hypocalcemia (serum calcium <8.5 mg/dL) postoperatively. The median PTH of 15.8 pg/mL in the hypocalcemic group was significantly lower than the median PTH of 41.6 pg/mL in the normocalcemic group (p < 0.001). Using a PTH threshold of 26 pg/mL, hypocalcemia was predicted with a sensitivity of 75%, and specificity of 100%. Six patients with calcium <7.5 mg/dL received teriparatide injections to avoid intravenous calcium replacement. The length of hospital stay for normocalcemic patients was 1.7 ± 0.8 days vs. 2.9 ± 1.4 days for hypocalcemic patients (p = 0.002). We found no correlation between the incidence of hypocalcemia and pathologic indication for surgery. Completion thyroidectomy was associated with a lower risk of hypocalcemia when compared to total thyroidectomy (p = 0.01) and neck dissections carried an increased risk of postoperative hypocalcemia (p = 0.04).

CONCLUSION

Postoperative PTH level has an excellent specificity in predicting hypocalcemia in this pediatric cohort using a threshold of PTH ≤ 26 pg/mL. Those with PTH >26 pg/mL may avoid hypocalcemia by oral calcium replacement with outpatient follow-up. We did not identify a reliable PTH cutoff value above which pediatric patients may be safely discharged immediately following surgery. Adult guideline or pathways that advocate for outpatient thyroidectomy surgery based on normal PTH ≥10 pg/mL in the recovery room may not apply to children.

Morbidity in patients with permanent hypoparathyroidism after total thyroidectomy

BACKGROUND

Permanent hypoparathyroidism is common after thyroidectomy. The present study evaluated the risk for morbidity in patients operated with total thyroidectomy with and without permanent hypoparathyroidism.

METHODS

Data was retrieved from the Scandinavian Quality Register for Thyroid, Parathyroid, and Adrenal Surgery and cross-linked with the Swedish National Prescription Registry for Pharmaceuticals, the National Data Inpatient Registry, and Causes of Death Registry. Patients with benign thyroid disease were included. Permanent hypoparathyroidism was defined as treatment with active vitamin D for more than 6 months after thyroidectomy. Analyzed morbidity was evaluated by multivariable Cox's regression analysis and presented as hazard ratio and 95% confidence interval.

RESULTS

There were 4,828 patients. The mean (standard deviation) follow-up was 4.5 (2.4) years. Some 239 (5.0 %) patients were medicated for permanent hypoparathyroidism. Patients with permanent hypoparathyroidism had an increased risk for renal insufficiency, hazard ratio 4.88 (2.00-11.95), and an increased risk for any malignancy, hazard ratio 2.15 (1.08-4.27). Patients with permanent hypoparathyroidism and known cardiovascular disease at the time of thyroidectomy had an increased risk for cardiovascular events during follow-up, hazard ratio 1.88 (1.02-3.47).

CONCLUSION

Patients with permanent hypoparathyroidism after total thyroidectomy have an increased risk of long-term morbidity. These results are a cause of great concern.

Imaging or Fiber Probe-Based Approach? Assessing Different Methods to Detect Near Infrared Autofluorescence for Intraoperative Parathyroid Identification

BACKGROUND

Near infrared autofluorescence (NIRAF) can guide intraoperative parathyroid gland (PG) identification. NIRAF detection devices typically rely on imaging and fiber probe-based approaches. Imaging modalities provide NIRAF pictures on adjacent display monitors, and fiber probe-based systems measure tissue NIRAF and provide real-time quantitative information to objectively aid PG identification. Both device types recently gained FDA approval for PG identification but have never been compared directly.

STUDY DESIGN

Patients undergoing thyroidectomy and/or parathyroidectomy were recruited prospectively. Target tissues were intraoperatively visualized with PDE-Neo II (imaging-based) and concurrently assessed with PTeye (fiber probe-based). For PDE-Neo II, NIRAF images were collected from in situ or excised tissues, alongside the surgeon's interpretation of visualized tissues, and retrospectively analyzed in a blinded fashion. The PTeye was concomitantly used to record NIRAF intensities and ratios from the same tissues in real time.

RESULTS

Twenty patients were enrolled for concurrent evaluation with both systems, which included 33 PGs and 19 nonparathyroid sites. NIRAF imaging demonstrated 90.9% sensitivity, 73.7% specificity, and 84.6% accuracy for PG identification when interpreted in real time by the surgeon compared with 81.8% sensitivity, 73.7% specificity, and 78.8% accuracy where images were quantitatively analyzed post hoc by an independent observer. In parallel, NIRAF detection with PTeye yielded 97.0% sensitivity, 84.2% specificity, and 92.3% accuracy in real time for the same specimens.

CONCLUSIONS

Both NIRAF-based systems were beneficial for identifying PGs intraoperatively. Although NIRAF imaging provides valuable spatial information to localize PGs, NIRAF detection with fiber probe provides real-time quantitative information to identify PGs in presence of ambient room lights.

FIRST DAY SERUM CALCIUM AND PARATHYROID HORMONE LEVELS AS PREDICTIVE FACTORS FOR SAFE DISCHARGE AFTER THYROIDECTOMY

Context

Permanent hypocalcemia is a rare but significant complication of thyroid surgery.

Objective

The aim of this study was to identify predictive factors of hypocalcemia and hypoparathyroidism after thyroidectomy.

Design

Study included 134 total patients submitted to thyroidectomy from two endocrine units (January 2015 - August 2016).

Methods

We measured total serum calcium (sCa) and intact PTH (iPTH) on postoperative day one and 1 month after surgery.

Results

118 patients were women with F/M ratio of 7.3/1 and a mean age of 51.8 years. 64 patients were included in group A (iPTH <12 pg/mL) and 70 patients in group B (iPTH >12 pg/mL). sCa and hypocalcemia symptoms were correlated with iPTH, measured 24 hours after surgery. The cut-off value was for sCa 8.05 mg/dL with a sensitivity of 85.29% and a specificity of 88.0% and for iPTH 11.2 pg/mL, with a sensitivity of 82.3% and a specificity of 71.0%. SCa (< 8.05 mg/dL) was a predictive factor with a 99 (IC95%:12.86-761.58) and iPTH (<11.2 pg/mL) with a 10.77 higher risk (CI95%: 3.83-30.30) to be associated with symptoms.

Conclusion

SCa and iPTH represent good predictive factors of early and safe hospital discharge and can predict the risk of prolonged and permanent hypoparathyroidism.

Preoperative vitamin D levels do not relate with the risk of hypocalcemia following total thyroidectomy. A cohort study

BACKGROUND

Hypocalcemia is the most common complication following total thyroidectomy. Few factors may relate with increased risk of postoperative hypocalcemia. Preoperative vitamin D values have been evaluated in few studies, but reports present conflicting data. Aim of our study is to evaluate the association of preoperative vitamin D values and hypocalcemia following total thyroidectomy.

METHODS

A retrospective analysis of patients undergoing total thyroidectomy in our department of endocrine surgery between November 2012 and November 2015 was performed.

RESULTS

Mean age of patients was 56.2 years (±14.0) and sex ratio (F:M) was 4.3:1. Sixty-four patients (17.4%) had preoperative vitamin D insufficiency (x<25 nmol/L), 138 patients (37.5%) vitamin D deficiency (25<x<50 nmol/L) and 166 patients (45.1%) vitamin D sufficiency (x>50 nmol/L). Following total thyroidectomy for both benign and malignant pathology, 66 patients (17.9%) had symptomatic hypocalcemia (x<2.0 mmol/L) requiring medical treatment (group 1), 64 patients (17.4%) biochemical hypocalcemia (2<x<2.1 mmol/L) not requiring treatment (group 2) and 238 patients (64.7%) had normal levels (x>2.1 mmol/L, group 3). Mean postoperative PTH value was 25.4 pg/ml (range 2-61). No statistical correlation between postoperative serum calcium and preoperative vitamin D values (R=-0.001, P=0.9849) was found nor associations were found regarding age, sex, type of thyroid disease or BMI.

CONCLUSIONS

In our cohort of patients, preoperative vitamin D levels were not associated with a higher risk of hypocalcemia following total thyroidectomy. Postoperative PTH appears to be the most sensible item to predict the risk of postoperative symptomatic hypocalcemia.

Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria.

Preoperative vitamin D level as a post-total thyroidectomy hypocalcemia predictor: a prospective study

Introduction

Hypocalcemia is one of the most common complications after total thyroidectomy. Preoperative serum vitamin D concentration has been postulated as a risk factor for this complication. However, the subject is still controversial and the role of vitamin D in the occurrence of hypocalcemia remains uncertain.

Objective

To evaluate the capability of preoperative vitamin D concentrations in predicting post-total thyroidectomy hypocalcemia.

Methods

Forty-seven total thyroidectomy patients were prospectively evaluated for serum 25(OH) vitamin D, calcium and parathyroid hormone before surgery, Calcium every 6 hours, and parathyroid hormone 8 hours post-operatively. Patients were divided according to postoperative corrected calcium into groups without (corrected calcium ≥8.5 mg/dL) and with hypocalcemia (corrected calcium <8.5 mg/dL), who were then evaluated for preoperative 25(OH) vitamin D values.

Results

A total of 72.3% of cases presented altered 25(OH) vitamin D preoperative serum concentrations and 51% evolved with postoperative hypocalcemia. The with and without hypocalcemia groups did not differ for preoperative 25(OH) vitamin D (p = 0.62). Univariate analysis showed that age (p = 0.03), postoperative PTH concentration (p = 0.02), and anatomopathological diagnosis of malignancy (p = 0.002) were predictors of postoperative hypocalcemia. In multivariate analysis only parathyroid hormone in postoperative (p = 0.02) was associated with post-total thyroidectomy hypocalcemia.

Conclusion

Preoperative serum concentrations of 25(OH) vitamin D were not predictors for post-total thyroidectomy hypocalcemia, whereas postoperative parathyroid hormone influenced the occurrence of this complication.

Impact of surgical volume and surgical outcome assessing registers on the quality of thyroid surgery

The available evidence concerning the relationship between volume and outcome for thyroid surgery is assessed in this article. Morbidity forms the principal surrogate marker of thyroid surgery quality for which postoperative hypocalcaemia and recurrent laryngeal nerve injuries are most commonly reported upon. Whilst there is an abundance of published data for these outcomes, interpretation to recommend annual volume thresholds is challenging. This is due to a lack of consensus on definitions not only for outcomes but high and low volume surgeons. The evidence reviewed in this article supports the notion that high volume surgeons achieve superior outcomes in thyroid surgery quality though it is not possible to recommend minimal annual volumes on the basis of this evidence alone. Every thyroid surgeon should know their own outcomes and how they compare with their peers and engagement in thyroid surgery registries can facilitate this.

Impact of fluorescence and autofluorescence on surgical strategy in benign and malignant neck endocrine diseases

Fluorescence and autofluorescence have been shown by several recent studies to be valuable adjuncts in identifying parathyroid glands during thyroidectomy and parathyroidectomy. The aim of this chapter is to review the impact of this new technology on surgical strategy concerning identification and preservation of parathyroid glands during thyroidectomy, identification of parathyroid glands in hyperparathyroidism, and the potential role in thyroid cancer surgery.

Preoperative vitamin D deficiency is a risk factor for postoperative hypocalcemia in patients undergoing total thyroidectomy: retrospective cohort study

BACKGROUND

The relationship between preoperative vitamin D deficiency and postoperative hypocalcemia in cases of total thyroidectomy (TT) is a matter of controversy and may vary according to geographical scenarios and populations.

OBJECTIVE

The objective here was to evaluate whether preoperative vitamin D deficiency was associated with postoperative symptomatic hypocalcemia in a population in South America.

DESIGN AND SETTING

Retrospective cohort study on data from all patients undergoing total thyroidectomy, with or without central compartment lymph node dissection, from January 2014 to December 2017, at the A. C. Camargo Cancer Center.

METHODS

Patients with benign thyroid disease (Graves' disease, multinodular goiter or hyperthyroidism) or thyroid cancer who underwent primary total thyroidectomy with or without central compartment lymph node dissection were included. The exclusion criteria were simultaneous parathyroidectomy and conditions that could affect serum calcium levels. The data collected included patient demographics, thyroid pathology, extent of the surgical procedure and complications. Information on preoperative and postoperative calcium, parathyroid hormone (PTH) and vitamin D levels were retrieved from the medical records.

RESULTS

1,347 patients were assessed and postoperative hypocalcemia was diagnosed in 284 patients (21%). The vitamin D levels were considered deficient in 243 patients (18%). Postoperative hypocalcemia was diagnosed in 357 patients (31.5%). Multivariate analysis showed that central compartment dissection and preoperative total calcium and deficient vitamin D levels were significant risk factors for postoperative hypocalcemia.

CONCLUSION

Deficient preoperative vitamin D levels were a significant risk factor for postoperative hypocalcemia. Preoperative oral supplementation should be considered, to minimize this risk.

Predicting transient hypocalcemia in patients with unplanned parathyroidectomy after thyroidectomy

OBJECTIVE

To assess the utility of rapid parathyroid hormone (PTH) values in predicting transient post-operative hypocalcemia in patients with unplanned parathyroidectomy during total or completion thyroidectomy.

METHODS

All patients who underwent total or completion thyroidectomy between January 2010 and January 2015 were reviewed. Incidences of post-operative hypocalcemia were compared in patients with and without unplanned parathyroidectomy. Unplanned parathyroidectomy was defined as intra-operative incidental or intentional parathyroidectomy. Logistic regression assessed for predictors of hypocalcemia and optimum amount of calcium supplementation.

RESULTS

Thirty-eight (13.6%) patients had evidence of incidental parathyroidectomy and 39/280 (13.9%) patients had parathyroid autotransplantation intra-operatively. Central neck dissection and malignancy were identified as risk factors for unplanned parathyroidectomy (p = 0.001, p = 0.060). Patients with unplanned parathyroidectomy were more likely to have hypocalcemia (p = 0.002) and hypoparathyroidism (p < 0.0005). PTH value was the only significant predictor of hypocalcemia in these patients. In patients with a post-operative PTH of ≤15, initial calcium supplementation ≥ 1000 mg decreased the risk of hypocalcemia (p < 0.05).

CONCLUSION

Post-operative PTH value predicts hypocalcemia in patients undergoing total and completion thyroidectomy with unplanned parathyroidectomy. In patients with a post-operative PTH < 15, initial calcium supplementation with ≥1000 mg of elemental calcium is recommended.

Post-thyroidectomy Hypocalcemia in Patients With History of Bariatric Operations: Current Evidence and Management Options

BACKGROUND/AIM

Both bariatric and thyroid surgeries promote calcium and vitamin D deficiency. The correlation, however, of hypocalcemia after thyroidectomy in patients with previous bariatric surgery has been poorly described. This review aimed to investigate the relationship between history of bariatric operations and post-thyroidectomy hypocalcemia, as well as suggested management options.

MATERIALS AND METHODS

MEDLINE and Cochrane databases were searched for relevant publications regarding post-thyroidectomy hypocalcemia in patients with previous bariatric surgery.

RESULTS

A total of 17 publications reporting on 126 patients met the inclusion criteria. These included 13 publications about Roux-en-Y gastric bypass (RYGB), 2 regarding biliopancreatic diversion (BPD), 1 about sleeve gastrectomy (SG) and 1 compared three bariatric procedures: SG, RYGB, laparoscopic adjustable gastric band (LAGB). Post-thyroidectomy hypocalcemia was found to be more prevalent in patients with previous RYGB and BPD, but not in previous LAGB and SG.

CONCLUSION

Patients with previous bariatric surgery are at high risk of post-thyroidectomy hypocalcemia that sometimes leads to higher length of hospital stay and demands more invasive solutions. There is a need, however, for additional studies and further investigation in order to reach more conclusive results.

Executive summary of the SEORL CCC-SEEN consensus statement on post-thyroidectomy hypoparathyroidism

Hypoparathyroidism is the most common complication after total or completion thyroidectomy. It is defined as the presence of hypocalcemia accompanied by low or inappropriately normal parathyroid hormone (PTH) levels. Acute hypocalcemia is a potential lethal complication. Hypocalcemia treatment is based on endovenous or oral calcium supplements as well as oral calcitriol, depending on the severity of the symptoms. The risk of clinical hypocalcemia after bilateral thyroidectomy is considered very low if postoperative intact PTH decrease less than 80% with respect to preoperative levels. These patients could be discharged home without treatment, although this threshold may vary between institutions, and we recommend close surveillance in cases with increased risk (Graves disease, large goiters, reinterventions or evidence of parathyroid gland removal). Long-term treatment objectives are to control the symptoms and to keep serum calcium levels at the lower limit of the normal range, while preserving the calcium phosphate product and avoiding hypercalciuria.

Calcium, vitamin D or recombinant parathyroid hormone for managing post-thyroidectomy hypoparathyroidism

BACKGROUND

Post-surgical hypoparathyroidism is a common complication after thyroid surgery. The incidence is likely to increase given the rising trend in the annual number of thyroid operations being performed. Measures to prevent post-thyroidectomy hypoparathyroidism including different surgical techniques and prophylactic calcium and vitamin D supplements have been extensively studied. The management of post-thyroidectomy hypoparathyroidism however has not been extensively evaluated. Routine use of calcium and vitamin D supplements in the postoperative period may reduce the risk of symptoms, temporary hypocalcaemia and hospital stay. However, this may lead to overtreatment and has no effect on long-term hypoparathyroidism. Current recommendations on the management of post-thyroidectomy hypoparathyroidism is based on low-quality evidence. Existing guidelines do not often distinguish between surgical and non-surgical hypoparathyroidism, and transient and long-term disease.The aim of this systematic review was to summarise evidence on the use of calcium, vitamin D and recombinant parathyroid hormone in the management of post-thyroidectomy hypoparathyroidism. In addition, we aimed to highlight deficiencies in the current literature and stimulate further work in this field.

OBJECTIVES

The objective of this systematic review was to assess the effects of calcium, vitamin D and recombinant parathyroid hormone in managing post-thyroidectomy hypoparathyroidism.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PubMed, Embase as well as ICTRP Search Portal and ClinicalTrials.gov. The date of the last search for all databases was 17 December 2018 (except Embase, which was last searched on 21 December 2017). No language restrictions were applied.

SELECTION CRITERIA

We planned to include randomised control trials (RCTs) or controlled clinical trials (CCTs) examining the effects of calcium, vitamin D or recombinant parathyroid hormone in people with temporary and long-term post-thyroidectomy hypoparathyroidism.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full texts for relevance.

MAIN RESULTS

Database searches yielded a total of 1751 records. We retrieved potentially relevant full texts and excluded articles on the following basis: not a RCT or CCT; intervention, comparator or both did not match prespecified criteria; non-surgical causes of hypoparathyroidism, and studies on prevention. None of the articles was eligible for inclusion in the systematic review.

AUTHORS' CONCLUSIONS

This systematic review highlights a gap in the current literature and the lack of high-quality evidence in the management of post-thyroidectomy temporary and long-term hypoparathyroidism. Further research focusing on clinically relevant outcomes is needed to examine the effects of current treatments in the management of temporary and long-term post-thyroidectomy hypocalcaemia.

Design of a predictive score to assess the risk of developing hypocalcemia after total thyroidectomy. A retrospective study

Background: Temporary hypocalcemia is the most common complication in patients after total thyroidectomy. To date, according to the literature, various predictors of the above complication have been proposed, but none of them seems to be effective enough. Objectives: The aim of this study was to develop a reliable predictive tool for biochemical hypocalcemia in the first 48 hrs after total thyroidectomy without central dissection by analyzing several parameters relevant to this operation and to suggest a new score. Methods: A retrospective study was performed on patients who had undergone total thyroidectomy without central neck dissection from October 2017 until January 2018. Data were collected from 36 patients and studied if there was a statistically significant relationship between the risk of hypocalcemia and 10 preselected prognostic factors. Results: The prognostic score was formed, which included the 6 factors that showed a statistically significant relationship. Moreover, an extensive check of the predictive value of the above score was performed. It was found, therefore, that at a value of 3 and above the sensitivity was 100%, the specificity 79.16%, the positive prognostic value (PPV) 70.58% and the negative predictive value (NPV) 100%. Conclusions: High sensitivity of CaReBe'S TiP score makes it feasible to predict patients with postoperative hypocalcemia. High NPV would allow surgeons to exclude patients with a score less than 3 from supplementary calcium medication and achieve a shorter hospitalization for them.

Hypocalcemia after Total Thyroidectomy in Graves Disease

CONTEXT

Total thyroidectomy has been shown to provide a cost-effective and efficient method of permanently treating Graves disease; however, hypocalcemia can be a common complication.

OBJECTIVE

To evaluate the risk of hypocalcemia after total thyroidectomy in patients with vs without Graves disease.

DESIGN

The 2016 American College of Surgeons National Surgical Quality Improvement Program participant use data files for procedure-targeted thyroidectomy and from 5871 patients were merged. This study included any patient who underwent total thyroidectomy.

MAIN OUTCOME MEASURES

Whether symptomatic hypocalcemia developed anytime within 30 days after the thyroidectomy. A clinically severe hypocalcemic event was also evaluated as a secondary outcome measure.

RESULTS

Of the 2143 patients who underwent total thyroidectomy, 222 patients experienced hypocalcemia after surgery, 124 of whom had symptomatic hypocalcemia postoperatively. Among patients with hypocalcemia, 16.3% had Graves disease, whereas only 9.4% of patients without Graves disease experienced significant hypocalcemia. Multivariable logistic regression analysis revealed that women (odds ratio = 1.79; 95% confidence interval = 1.16-2.76; p = 0.009) and patients who underwent parathyroid autotransplantation (odds ratio = 1.91; 95% confidence interval = 1.30-2.81; p = 0.001) were at greater risk of development of hypocalcemia. Older patients were less likely to experience hypocalcemia postoperatively (odds ratio = 0.586; 95% confidence interval = 0.44-0.79; p = 0.0001).

CONCLUSION

Patients with Graves disease are about twice as likely to experience hypocalcemia or clinically severe hypocalcemia postoperatively than are patients without the disease.

Enhancing Parathyroid Gland Visualization Using a Near Infrared Fluorescence-Based Overlay Imaging System

BACKGROUND

Misidentifying parathyroid glands (PGs) during thyroidectomies or parathyroidectomies could significantly increase postoperative morbidity. Imaging systems based on near infrared autofluorescence (NIRAF) detection can localize PGs with high accuracy. These devices, however, depict NIRAF images on remote display monitors, where images lack spatial context and comparability with actual surgical field of view. In this study, we designed an overlay tissue imaging system (OTIS) that detects tissue NIRAF and back-projects the collected signal as a visible image directly onto the surgical field of view instead of a display monitor, and tested its ability for enhancing parathyroid visualization.

STUDY DESIGN

The OTIS was first calibrated with a fluorescent ink grid and initially tested with parathyroid, thyroid, and lymph node tissues ex vivo. For in vivo measurements, the surgeon's opinion on tissue of interest was first ascertained. After the surgeon looked away, the OTIS back-projected visible green light directly onto the tissue of interest, only if the device detected relatively high NIRAF as observed in PGs. System accuracy was determined by correlating NIRAF projection with surgeon's visual confirmation for in situ PGs or histopathology report for excised PGs.

RESULTS

The OTIS yielded 100% accuracy when tested ex vivo with parathyroid, thyroid, and lymph node specimens. Subsequently, the device was evaluated in 30 patients who underwent thyroidectomy and/or parathyroidectomy. Ninety-seven percent of exposed tissue of interest was visualized correctly as PGs by the OTIS, without requiring display monitors or contrast agents.

CONCLUSIONS

Although OTIS holds novel potential for enhancing label-free parathyroid visualization directly within the surgical field of view, additional device optimization is required for eventual clinical use.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Routine low-dose calcium supplementation after thyroidectomy does not reduce the rate of symptomatic hypocalcemia: a prospective randomized trial

Purpose

Routine supplementation of high-dose calcium significantly decreased the risk of postoperative symptomatic hypocalcemia after thyroidectomy. However, there is an ongoing debate about whether the same results can be achieved with low-dose calcium supplementation.

Methods

Patients (n = 138) who underwent total thyroidectomy for thyroid cancer were 1:1 randomly assigned to receive oral supplements of 1,500 mg/day elemental calcium and 1,000 IU/day cholecalciferol for 2 weeks or no supplementation. Primary objective was to compare the incidence of symptomatic hypocalcemia for 3 days after total thyroidectomy. Secondary objective was to find the predictors for postoperative hypocalcemia in patients with thyroid cancer.

Results

Sixty-five patients in the calcium group and 69 patients in the control group were finally analyzed. The incidence of symptomatic hypocalcemia showed no difference between the calcium and control group (32.3% vs. 21.7%, P = 0.168). The total dosage of intravenous calcium (593.4 ± 267.1 mg vs. 731.6 ± 622.7 mg, P = 0.430) administered to patients with symptomatic hypocalcemia was also comparable between groups. In a multivariate analysis, parathyroid hormone level of 13 pg/mL at postoperative day 1 was only predictive for symptomatic hypocalcemia, and its incidence was 20.9 times (95% confidence interval, 6.8-64.5) higher in patients with parathyroid hormone <13 pg/mL. Other factors did not predict the development of hypocalcemia, including clinicopathological features and routine supplementation of low-dose calcium.

Conclusion

Routine low-dose calcium supplementation did not reduce the risk of postoperative hypocalcemia. Patients who may benefit from calcium supplementation should be carefully selected.

Quantitative Assessment of the Learning Curve for Robotic Thyroid Surgery

With the increased utilization of robot thyroidectomy in recent years, surgical proficiency is the paramount consideration. However, there is no single perfect or ideal method for measuring surgical proficiency. In this study, we evaluated the learning curve of robotic thyroidectomy using various parameters. A total of 172 robotic total thyroidectomies were performed by a single surgeon between March 2014 and February 2018. Cumulative summation analysis revealed that it took 50 cases for the surgeon to significantly improve the operation time. Mean operation time was significantly shorter in the group that included the 51st to the 172nd case, than in the group that included only the first 50 cases (132.8 ± 27.7 min vs. 166.9 ± 29.5 min; p < 0.001). On the other hand, the surgeon was competent after the 75th case when postoperative transient hypoparathyroidism was used as the outcome measure. The incidence of hypoparathyroidism gradually decreased from 52.0%, for the first 75 cases, to 40.2% after the 76th case. These results indicated that the criteria used to assess proficiency greatly influenced the interpretation of the learning curve. Incorporation of the operation time, complications, and oncologic outcomes should be considered in learning curve assessment.

Management of Endocrine Emergencies in the ICU

Endocrine emergencies are frequent in critically ill patients and may be the cause of admission or can be secondary to other critical illness. The ability to anticipate endocrine abnormalities such as adrenal excess or , hypothyroidism, can mitigate their duration and severity. Hyperglycemic crisis may trigger hospital and intensive care unit (ICU) admission and may be life threatening. Recognition and safe treatment of severe conditions such as acute adrenal insufficiency, thyroid crisis, and hypoglycemia and hyperglycemic crisis may be lifesaving. Electrolyte abnormalities such as hypercalcemia and hypocalcemia may have underlying endocrine causes, and may be treated differently with recognition of those disorders- electrolyte replacement alone may not be adequate for efficient resolution. Sodium disorders are common in the ICU and are generally related to altered water balance however may be related to pituitary abnormalities in selected patients, and recognition may improve treatment effectiveness and safety.

Research on indocyanine green angiography for predicting postoperative hypoparathyroidism

BACKGROUND

It may be critical to locate the parathyroid for surgeons during thyroidectomy or parathyroidectomy due to the significant function of the parathyroid in calcium balance. According to recent reports, the intrinsic fluorescence of the parathyroid has been found. There is some evidence supporting that new equipment can detect fluorescence via imaging technology. In this study, a newly invented intraoperative fluorescence imaging system and indocyanine green dye were applied to detect the parathyroid glands and evaluate the vascularization of the parathyroid. The report is as follows.

METHODS

From 1 May to 8 August 2018, 26 patients underwent total thyroidectomy in Zhuhai People's Hospital and were recruited into our research. All identified parathyroid glands were scored visually from grade 0 to grade 2 according to the vascularity of the parathyroid before ICG angiography was performed. After ICG angiography, parathyroid glands were scored from score 0 to score 2 according to the FI.

RESULTS

Visual scores were significantly higher than ICG angiography scores. In the 22 patients with at least one parathyroid gland with an ICG score of 2, postoperative PTH levels were in the normal range. In the four patients with no parathyroid gland with an ICG score of 2, two of them developed transient hypoparathyroidism, with recovery on POD 7 for the first patient and after 3 months for the second one.

CONCLUSION

This study has identified that the fluorescence imaging system applied with indocyanine green is a safe, easy and effective method to protect the parathyroid and predict postoperative hypoparathyroidism. Registration number: ChiCTR1800016864.