Recovery of parathyroid function after total thyroidectomy

Total Number of Identified Parathyroid Glands During Total Thyroidectomy and Its Relation to Postoperative Hypoparathyroidism

OBJECTIVES

To evaluate the correlation between the intraoperative number of identified parathyroid glands (PGs) and the risk of developing hypoparathyroidism postoperatively. Also, to determine the risks and prognostic factors in patients with postoperative hypoparathyroidism.

METHODS

A retrospective study of 499 patients who underwent total thyroidectomy at two tertiary care institutions, King Saud University Medical City (KSUMC) and King Fahad Medical City (KFMC) in Riyadh, Saudi Arabia was included. Individual demographic characteristics with detailed clinical information were recorded, focusing mainly on operative reports for a total number of identified PGs intraoperatively and investigating the risk of developing hypoparathyroidism postoperatively. Factors such as age, gender, comorbidity, and number of excised and reimplanted parathyroid glands were investigated to determine the risks and prognostic factors in patients with postoperative hypoparathyroidism.

RESULTS

The findings from the analysis showed that the number of identified PGs intraoperatively had a positive correlation with a higher postoperative risk of developing hypoparathyroidism. For zero, one, two, three, and four identified PGs, the risk of hypoparathyroidism in one-hour parathyroid hormone level postoperative was 6.6%, 7.3%, 34.4%, 34.4%, and 17.2% respectively.

CONCLUSION

The greater the number of identified PGs intraoperatively, the less likely it was to prevent inadvertent hypoparathyroidism post-total thyroidectomy.

Impact of Clinico Pathological and Surgical Related Risk Factor in Post Operative Hypoparathyroidism in Total Thyroidectomy Patients

Multiple risk factors have been predicted in post operative hypoparathyroidism in total thyroidectomy patients but none have been clearly defined. Present study aims at evaluating the clinic pathological and surgical impact factors in predicting the risk of post operative hypoparathyroidism in thyroidectomy patients. The study was done in Karpaga Vinayaga Institute of Medical Science and Research Centre where Retrospective prospective cohort study who underwent and undergoing total thyroidectomy with or without central neck dissection for both benign and malignant thyroid disorders during 2014 to 2022 was analyzed. The study has analyzed the various risk factors from clinic pathological and surgical skills of identifying the Inferior thyroid artery at its origin and tracing the branches to the parathyroid gland and evaluating the incidence of hypocalcemia in both study and control groups. Two groups were analyzed during the period 2014 to 2022. The study group was included patients with thyroidectomy where ITA were identified and traced up to the parathyroid gland. They were further classified into category A where both sides ITA were identified and saved, category B where only one side was preserved. In control group, the surgery was done only on basis of capsular dissection and peripheral ligation of vessels close to the gland. Total study participants in our study was 416. The overall prevalence of hypocalcemia in our study was 11.4%. The age, gender and pathological variants were comparable between the two groups. Female preponderance (76%) was seen among both the groups. Among total study subjects who underwent total thyroidectomy 44.8% were having multi nodular goitre, 7.3% toxic goitre, 9.8% follicular adenoma, 30.2% papillary carcinoma and 7.9% follicular carcinoma. In our study benign and malignant thyroid disorders had no significant difference. Prevalence of hypocalcemia among control group 14.5% vs study group 3.8%. We found incidence of hypocalcaemia was comparitively lesser among patients with thyroidectomy alone, than those with unilateral or bilateral CND. Prevalence of hypocalcemia among control group was 33% (45/133) and study group 7% (12/153), when thyroidectomy alone was done. However, with neck dissection in bilateral CND, incidence was 41% (23/56) in study group and 61% (11/18) in control group. In unilateral CND, study and control group had 31% (10/32) and 54% (13/24) which was found to be statistically significant. Parathyroid auto transplantation among the control group (29%) compared to the study group (16%). Bilateral neck dissection and gross extrathyroidal extension and cases with PTG inadvertent removal posed significant risk factors for hypoparathyroidism. The prevalence of immediate hypocalcemia among Cat A, Cat B and control group were 14%, 20.3% and 37.5% respectively and was statistically significant (P < .0001). Symptomatic and Biochemical hypocalcemia at the end of 1 week among Cat A, Cat B, and control group was 8%, 12%, and 33.6, & 12.9%, 21% and 30% respectively. Whereas transient hypocalcemia reported among these groups was 1.6%, 5% and 14.6%. Permanent hypocalcemia was < 1% in study group and 4% among control group. We observed that permanent hypocalcemia was high among patients with bilateral neck dissection and auto transplanted PTG. There was no significant statistical difference in hypocalcemia (transient or permanent) among study and control group, but the incidence of hypocalcemia had significantly reduced in both study groups when unilateral or bilateral identification of ITA was done compared to control group. Our hypothesis in this study aims at preserving the branches of ITA supplying PTG distally has greater functional preservation of the parathyroid than conventional technique. This technique also helps us maintaining the plane and capsular dissection if done properly. By trying to preserve the ITA surgeons may acquire better meticulous dissection skills and understanding the anatomical variation of vessels around PTG more precisely which improve the surgical outcome in preventing both transient and permanent hypocalcaemia.

Effect of intraoperative active exploration of parathyroid glands to reduce the incidence of postoperative hypoparathyroidism, and risk factors of hypoparathyroidism after total thyroidectomy: a single-center study

Background

The risk factors for hypoparathyroidism after thyroid surgery have not been fully identified. This study analyzes the risk factors of hypoparathyroidism before and after total thyroidectomy.

Methods

We retrospectively collected the clinical data of 289 patients who underwent total thyroidectomy at the Thyroid Surgery Center of Lishui Central Hospital from June 2018 to June 2020. For the anatomy and protection of parathyroid glands during the operation, one group of patients used the parathyroid avoidance method, and the other group used the active exploration method. Various risk factors affecting parathyroid dysfunction were studied using logistic regression models.

Results

A total of 289 patients were included in this study. The average age of patients was 47.21 ± 11.78 years, including 57 males (19.7%) and 232 females (80.3%). There were 149 (51.6%) patients with transient hypoparathyroidism and 21 (7.3%) with permanent hypoparathyroidism. The main risk factors of hypoparathyroidism were parathyroid avoidance method (P = 0.005), parathyroid autotransplantation (P = 0.011), bilateral central neck lymph node dissection (CND) (P = 0.001), lymphatic metastasis (P = 0.039), and parathyroid in the specimen (P = 0.029). The main risk factors associated with permanent hypoparathyroidism were bilateral CND (P = 0.038), lymphatic metastasis (P = 0.047), parathyroid hormone (PTH) < 1.2 pg/ml within three days after surgery (P = 0.006).

Conclusion

Hypoparathyroidism is common but mostly transient after bilateral total thyroidectomy. Compared with parathyroid avoidance method, the active exploration method during operation may reduce the incidence of postoperative hypoparathyroidism. PTH <1.2 pg/ml within three days after surgery was predictive in patients with permanent hypoparathyroidism.

Classification of neck tissues in OCT images by using convolutional neural network

Identification and classification of surrounding neck tissues are very important in thyroid surgery. The advantages of optical coherence tomography (OCT), high resolution, non-invasion, and non-destruction make it have great potential in identifying different neck tissues during thyroidectomy. We studied the automatic classification for neck tissues in OCT images based on convolutional neural network in this paper. OCT images of five kinds of neck tissues were collected firstly by our home-made swept source (SS-OCT) system, and a dataset was built for neural network training. Three image classification neural networks: LeNet, VGGNet, and ResNet, were used to train and test the dataset. The impact of transfer learning on the classification of neck tissue OCT images was also studied. Through the comparison of accuracy, it was found that ResNet has the best classification accuracy among the three networks. In addition, transfer learning did not significantly improve the accuracy, but it can somewhat accelerate the convergence of the network and shorten the network training time.

The Effect of Parathyroid Gland Autotransplantation on Hypoparathyroidism After Thyroid Surgery for Papillary Thyroid Carcinoma

Purpose

There are some controversies over the relationship between parathyroid gland autotransplantation and permanent hypoparathyroidism. This study aimed to explore the relationship between parathyroid gland autotransplantation and postoperative hypoparathyroidism.

Patients and Methods

We performed a retrospective analysis of patients who underwent initial thyroid surgery for papillary thyroid carcinoma from January 2014 to December 2018. Patients were divided into 4 groups according to the number of autotransplanted parathyroid glands (group 1: 0 autotransplanted parathyroid gland, group 2: 1 autotransplanted parathyroid gland, group 3: 2 autotransplanted parathyroid glands, group 4: 3 autotransplanted parathyroid glands). Clinical data were analyzed among the four groups.

Results

The more parathyroid glands were transplanted, the higher the incidence of immediate hypoparathyroidism was (group 1: 32.9%, group 2: 52.9%, group 3: 65.8%, group 4: 82.4%; P_{group 1 vs group 2} < 0.001, P_{group 2 vs group 3} = 0.012, P_{group 3 vs group 4} = 0.17). Parathyroid gland autotransplantation did not affect the incidence of permanent hypoparathyroidism (group 1: 1.4%, group 2: 1.3%, group 3: 0.9%, group 4: 0%; P_{group 1 vs group 2} > 0.99, P_{group 2 vs group 3} > 0.99, P_{group 3 vs group 4} > 0.99).

Conclusion

The number of autotransplanted parathyroid glands was positively associated with the incidence of postoperative immediate hypoparathyroidism. Parathyroid gland autotransplantation was not associated with permanent hypoparathyroidism.

[Review of clinical practice guidelines for hypoparathyroidism]

Hypoparathyroidism is a rare disorder characterized by the absent or inappropriately decreased serum parathyroid hormone in the parathyroid glands, which is accompanied by impaired calcium-phosphorus metabolism.The main etiology of hypoparathyroidism remains damage or removal of the parathyroid glands during neck surgery. In view of the incidence of thyroid cancer, primary hyperparathyroidism and other pathologies of the neck organs, which radical treatment can lead to the parathyroid gland impairment, an increased number of patients with hypoparathyroidism is expected. Autoimmune hypoparathyroidism is the second most common form of the disease, usually occurring as part of type 1 autoimmune polyglandular syndrome. Autoimmune hypoparathyroidism usually occurs in childhood and is characterized by a severe course of the disease, especially in the case of concomitant malabsorption syndrome.Chronic hypoparathyroidism of any etiology requires lifelong multicomponent therapy, as well as careful monitoring and an individual approach to choose the optimal treatment strategy. In the absence of adequate follow-up, the risks of long-term complications significantly increase, particularly in the renal, cardiovascular systems; in the soft tissues and in the brain, it could lead to visual disturbances; pathology of the musculoskeletal system with a decreased bone remodeling and a potential risk of fractures, as well as to the neurocognitive disorders and an impaired health-related quality of life.Timely diagnosis, rational medical therapy and management strategy may reduce the risks of short-term and long-term complications, frequency of hospitalizations and disability of patients, as well as improve the prognosis.This review covers the main issues of Russian guidelines for the management of chronic hypoparathyroidism, approved in 2021, including laboratory and instrumental evaluation, treatment approaches and follow-up. This guidelines also include the recommendations for special groups of patients: with acute hypocalcemia, hypoparathyroidism during pregnancy.

The inferior parathyroid glands preserved in site recover faster than the superior parathyroid glands preserved in site after thyroid surgery for carcinoma

Due to the great difficulty in being preserved in site for the variable positions, the inferior parathyroid glands were advised to being routinely autotransplanted to prevent permanent hypoparathyroidism. The aim of this study was to compare the performance in the function of the superior parathyroid glands preserved in site with that of the inferior parathyroid glands preserved in site.We conducted a retrospective study including patients who underwent thyroid surgery for papillary thyroid carcinoma at our department between January 2014 and June 2018. According to the number and original position of the autoplastic parathyroid gland(s), patients were divided into group 1 (1 superior parathyroid gland), group 2 (1 inferior parathyroid glands), group 3 (1 superior parathyroid gland and 1 inferior parathyroid gland) and group 4 (2 inferior parathyroid glands). The postoperative complications and serum parathyroid hormone and calcium were analyzed.A total of 368 patients were included in the study, among them 27, 243, 40, and 58 patients were divided into group 1, group 2, group 3, and group 4, respectively. Compared with those in group 2, the serum parathyroid hormones were higher at 1 week (2.98 ± 1.52 vs 2.42 ± 0.89, P = .049) and 2 weeks (3.49 ± 1.42 vs 2.8 ± 0.81, P = .019) postoperatively in group 1. There was also significantly different in the serum parathyroid hormone at 2 weeks postoperatively between group 3 and group 4 (2.95 ± 0.98 vs 2.58 ± 0.82, P = .047).The inferior parathyroid glands preserved in site recover faster than the superior parathyroid glands preserved in site.

Prediction of post-idroidectomy hypocalcemia through rapid PTH determination

INTRODUCTION

Hypocalcemia is the most frequent complication after thyroidectomy. The aim of this work is to identify biochemical risk factors of hypocalcemia using quick perioperative (pre and post-thyroidectomy) intact parathyroid hormone (PTHi) and postoperative calcemias.

METHODS

In a consecutive series of 310 total thyroidectomies, samples of quick PTHi at the anaesthetic induction and 10 minutes after surgery, together with serum calcemias every 12 hours were obtained. The sensitivity, specificity, positive and negative predictive value are analyzed and related to hypocalcemia. A control group of hemithyroidectomies is also analyzed to compare the effects of surgery on PTH secretion.

RESULTS

Of the 310 patients, 202 (65.1%) remained normocalcemic and asymptomatic (group A), 108 (34.9%) presented hypocalcemia (Group B), requiring oral calcium (79 symptomatic). After analysis of several cut-off points, combining a PTHr drop gradient of 60% or calcemia inferior to 7.4 mg/dl at 24 hours, a sensitivity of 100% is achieved without leaving false negatives. Compared to the control group, there is a significant difference with respect to the post-operative calcemias and PTHr, p < 0.001.

CONCLUSIONS

Total thyroidectomy affects parathyroid function with evident decrease in rPTH and risk of hypocalcemia. The combination of PTHr decrease of 60% or less than 7.4 mg/dl calcemia at 24 hours gives a 100% sensitivity for predicting patients at risk of hypocalcemia.

Application of Nanocarbon in Breast Approach Endoscopic Thyroidectomy Thyroid Cancer Surgery

Objective: This study aimed to investigate the application of nanocarbon in surgical endoscopy in patients with thyroid cancer for the clinical tracing of level VI sentinel lymph nodes (SLNs) and for parathyroid gland protection. Materials and Methods: Ninety-three patients with papillary thyroid carcinoma (PTC) who underwent an endoscopic thyroid cancer operation were included. We randomly divided these patients into a control group (n = 42) and a nanocarbon group (n = 51). For the nanocarbon group, after thyroid exposure, nanocarbon was injected into the thyroid gland, and the SLNs were resected and subjected to frozen sectioning and routine pathological examination. In addition, the postoperative calcium and parathyroid hormone (PTH) levels of both groups were analyzed to compare the features of the nanocarbon application. Results: The number of central lymph (level VI) nodes dissected and the number of metastatic lymph nodes identified were analyzed in both groups. The number of dissected lymph nodes from both unilateral and bilateral thyroid surgeries was significantly larger in the nanocarbon group than in the control group. At the same time, the number of identified metastasis lymph nodes dissected were higher in the nanocarbon group than in the control group. We assessed the postoperative calcium and PTH level to evaluate the parathyroid function. Our results show that the nanocarbon group had a better protective effect on parathyroid function than the control group. Conclusions: As a lymph node trace agent, nanocarbon could better evaluate and permit a more clear lymph dissection for patients with PTC. Nanocarbon contributes to a decrease in the incidence rate of parathyroid damage, which has great clinical value.

The effectiveness of parathyroid gland autotransplantation in preserving parathyroid function during thyroid surgery for thyroid neoplasms: A meta-analysis

Objective

We conducted this meta-analysis to assess the effectiveness of parathyroid gland autotransplantation in preserving parathyroid function during thyroid surgery for thyroid neoplasms.

Methods

We conducted a search by using PubMed, Embase, and the Cochrane Library electronic databases for studies that were published up to January 2019. The reference lists of the retrieved articles were also reviewed. Two authors independently assessed the methodological quality and extracted the data. A random-effects model was used to calculate the overall combined risk estimates. Publication bias was evaluated with a funnel plot using Egger’s and Begg’s tests.

Results

A total of 25 independent studies involving 10,531 participants were included in the meta-analysis. Compared with patients who did not undergo parathyroid gland autotransplantation, the overall pooled relative risks for patients who underwent parathyroid gland autotransplantation were 1.75 (95% CI: 1.51–2.02, p<0.001) for postoperative hypoparathyroidism, 1.72 (95% CI: 1.45–2.05, p<0.001) for protracted hypoparathyroidism, 1.06 (95% CI: 0.44–2.58, p = 0.894) and 0.71 (95% CI: 0.22–2.29, p = 0.561) for biochemical hypoparathyroidism and biochemical hypocalcemia at 6 months postoperatively, respectively, and 1.89 (95% CI: 1.33–2.69, p<0.001) and 0.22 (95% CI: 0.09–0.52, p = 0.001) for biochemical hypoparathyroidism and biochemical hypocalcemia at 12 months postoperatively, respectively. The pooled relative risks for patients who underwent one parathyroid gland autotransplantation and patients who underwent two or more parathyroid gland autotransplantations were 1.71 (95% CI: 1.25–2.35, p = 0.001) and 2.22 (95% CI: 1.43–3.45, p<0.001) for postoperative hypoparathyroidism, 1.09 (95% CI: 0.59–2.01, p = 0.781) and 0.55 (95% CI: 0.16–1.87, p = 0.341) for hypoparathyroidism at 6 months postoperatively compared with those of patients who did not undergo parathyroid gland autotransplantation.

Conclusions

Parathyroid gland autotransplantation is significantly associated with increased risk of postoperative and protracted hypoparathyroidism, and the number of autoplastic parathyroid glands is positively correlated with the incidence of postoperative hypoparathyroidism.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

A nomogram to predict the likelihood of permanent hypoparathyroidism after total thyroidectomy based on delayed serum calcium and iPTH measurements

Background

Retrospective studies have shown that delayed high-normal serum calcium and detectable iPTH are independent variables positively influencing outcome of prolonged parathyroid failure after total thyroidectomy (TT). The aim of the present study was to examine prospectively the ability of these two variables to predict permanent hypoparathyroidism in patients under replacement therapy for postoperative hypocalcemia.

Methods

Prospective observational multicenter study of patients undergoing TT followed by postoperative parathyroid failure (serum calcium <8 mg/dL within 24 h and PTH <15 pg/mL 4 h after surgery). Serum calcium, vitamin D and iPTH were determined before thyroidectomy, 24 h after surgery, at 1 month and then periodically until recovery of the parathyroid function or permanent hypoparathyroidism was diagnosed after at least 1 year follow-up.

Results

Some 145 patients with postoperative hypocalcemia were investigated [s-Ca^24h 7.5 (0.5) mg/dL]. Hypocalcemia recovered within 30 days in 91 (63%) patients and 54 (37%) developed protracted hypoparathyroidism {iPTH 5.8 [4] pg/mL at 1 month}, of whom 32 recovered within 1 year and 22 developed permanent hypoparathyroidism. Protracted hypoparathyroidism was related to few parathyroid glands remaining in situ (PGRIS). Serum calcium concentration (mg/dL) at 1 postoperative month correlated positively with the rate of recovery (percent) from protracted hypoparathyroidism: <8.5 (20%); 8.5-9 (29%); 9.1-9.5 (70%); 9.6-10 (89%); >10 (83%) (P=0.013). Serum iPTH at 1 month was also higher (7.3 vs. 3.7 pg/mL; P=0.002) in recovered protracted hypoparathyroidism. The combination of both variables predicts the likelihood of recovery of the parathyroid function with >90% accuracy.

Conclusions

High-normal serum calcium and low but detectable iPTH concentrations at 1 month after TT were associated with better outcome of protracted hypoparathyroidism. A nomogram combining both variables may guide medical treatment and monitoring of post-thyroidectomy prolonged hypoparathyroidism.

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy

BACKGROUND

Some investigators reported that among athyreotic patients on levothyroxine (LT4) monotherapy following total thyroidectomy, the patients with normal serum thyrotropin (TSH) levels had mildly low serum free triiodothyronine (fT3) levels, whereas the patients with mildly suppressed serum TSH levels had normal serum fT3 levels, and the patients with strongly suppressed serum TSH had elevated serum fT3 levels. The objective of the present study was to clarify which of these three patient groups is closer to their preoperative euthyroid condition.

METHODS

A total of 133 consecutive euthyroid patients with papillary thyroid carcinoma who underwent a total thyroidectomy were prospectively studied. The patients' serum levels of lipoproteins, sex hormone-binding globulin, and bone metabolic markers measured preoperatively were compared with the levels measured at postoperative LT4 therapy 12 months after the thyroidectomy.

RESULTS

The postoperative serum sex hormone-binding globulin (p < 0.001) and bone alkaline phosphatase (p < 0.01) levels were significantly increased in the patients with strongly suppressed TSH levels (≤0.03 μIU/mL). The postoperative serum low-density lipoprotein cholesterol levels were significantly increased (p < 0.05), and the serum tartrate-resistant acid phosphatase-5b levels were significantly decreased (p < 0.05) in the patients with normal TSH (0.3 < TSH ≤5 μIU/mL). In the patients with mildly suppressed TSH (0.03 < TSH ≤0.3 μIU/mL) and fT3 levels equivalent to their preoperative levels, all metabolic markers remained equivalent to their preoperative levels.

CONCLUSIONS

The serum biochemical markers of thyroid function in patients on LT4 following total thyroidectomy suggest that the patients with mildly suppressed TSH levels were closest to euthyroid, whereas those with normal TSH levels were mildly hypothyroid and those with strongly suppressed TSH levels were mildly hyperthyroid. These data may provide novel information on the management of patients following total thyroidectomy for thyroid cancer or benign thyroid disease.

Automatic identification of parathyroid in optical coherence tomography images

BACKGROUND AND OBJECTIVE

The identification and preservation of parathyroid is a major problem in thyroid surgery. In order to solve this problem, optical coherence tomography was involved as a real-time, non-invasive high-resolution imaging technique. This study demonstrated an effective and fast method to distinguish parathyroid tissue from thyroid, lymph node, and adipose tissue in their ex vivo optical coherence tomography (OCT) images automatically.

METHODS

OCT images were obtained from parathyroid, thyroid, lymph node, and adipose tissue, respectively. A classification and an identification system based on texture features analysis and back propagation artificial neural network (BP-ANN) were established to classify the four types of tissue and identify each of the four types automatically.

RESULTS

A total of 248 OCT images were taken from 16 patients undergoing thyroidectomy. The accuracy of classification for parathyroid, thyroid, lymph node, and adipose were 99.21, 98.43, 97.65, and 98.43%, respectively.

CONCLUSION

The proposed automatic identification method is capable of distinguishing among parathyroid, thyroid, lymph, and adipose automatically and effectively. Compared with the identification results of human, it has a better accuracy and reliability. For identifying parathyroid from the other entities, it has a satisfying performance. Lasers Surg. Med. 49:305-311, 2017. © 2017 Wiley Periodicals, Inc.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bilateral benign multinodular goiter: What is the adequate surgical therapy? A review of literature

BACKGROUND

Benign multinodular goiter (BMNG) is the most common endocrine disease requiring surgery. During the last few years a more aggressive approach has become the trend for bilateral BMNG treatment.

METHOD

Randomized clinical trials of any size that compared bilateral subtotal resection, Dunhill procedure and total thyroidectomy for benign multinodular goiter, published between January 2000 and the end of March 2015, were reviewed.

DISCUSSION

Total thyroidectomy can be considered the most reliable approach in preventing recurrence. The Dunhill procedure is related to a higher rate of recurrence, but rarely recurrences after Dunhill procedure lead to reoperation. Total thyroidectomy avoid completion thyroidectomy for incidental carcinoma and its related risks. Recurrent laryngeal nerve (RLN) palsy becomes less common as surgical experience increases. Transient and permanent hypoparathyroidism is strictly related to the extent of neck dissection. In the risk-cost analysis we must consider the type of patient candidated to surgery and the impact of the surgical protocol we apply. When thyroid surgery is taken in consideration, specific complication rates of different procedures in each hospital must be analyzed accordingly to patient-specific risk factors and local expertise.

CONCLUSION

The Dunhill procedure seems to be a good compromise between radicality and prevention of complications, avoiding reoperation for recurrence or completion thyroidectomy for incidental thyroid carcinoma. More follow-up studies and prospective studies are necessary to better evaluate, definitively, whether to prefer total thyroidectomy or Dunhill procedure in case of benign goiter surgery.

Application of nano-carbon in lymph node dissection for thyroid cancer and protection of parathyroid glands

Background

The aim of this study was to explore a new method to identify and protect parathyroid glands in neck lymph node dissection for patients with thyroid cancer.

Material/Methods

One hundred patients with thyroid cancer underwent total thyroidectomy combined with central neck lymph node dissection. During the operation, 50 patients receiving nano-carbon suspension were included in the experiment group, and 50 patients without nano-carbon suspension were included in the control group. We compared changes in parathyroid hormone levels before surgery and at 48 h after surgery between the 2 groups and of serum Ca²⁺ level within 48 h after surgery, as well as postoperative parathyroid pathological and lymph node dissection results.

Results

Eight and 1 parathyroid glands were detected pathologically in the control and experimental group, respectively. Decrease in parathyroid hormone level at 48 h occurred in 7 patients in the control group and 1 patient in the experimental group. Hypocalcemia was found at 48 h after surgery in 10 patients in the control group and 2 patients in the experimental group.

Conclusions

Nano-carbon suspension can cause development of the thyroid gland and the central lymph node and a negative development of parathyroid glands. Careful identification and removal of black-stained lymphatic tissues in the process of total thyroidectomy with neck lymph node dissection can ensure a complete lymph node dissection and prevent parathyroid damage, thus effectively reducing the incidence of hypoparathyroidism.

Permanent hypoparathyroidism after completion total thyroidectomy as a second surgery: How do we avoid it?

A permanent hypoparathyroidism is a problematic complication of total thyroidectomy. In this study, we investigated its incidence and how to avoid it at the time of completion total thyroidectomy after hemithyroidectomy. Eight of the 154 patients who underwent completion total thyroidectomy as the second surgery (5%) after hemithyroidectomy (two-surgery group) showed a permanent hypothyroidism. Patients without parathyroid autotransplantation either at initial or second surgery were more likely to show a permanent hypoparathyroidism. In the subset of 74 patients in two-surgery group, who underwent bilateral central dissection, 6 (8%) had a permanent hypoparathyroidism. The incidence was higher than those in control group who underwent total thyroidectomy with bilateral central dissection at one time, which was 2%. However, all 6 patients showing a permanent hypoparathyroidsm underwent bilateral central dissection in initial surgery and none of the patients who underwent bilateral central dissection in twice had a permanent hypoparathyroidism. Taken together, we can conclude that 1) in initial surgery of hemithyroidectomy, we have to carefully search the parathyroid glands and if dissected, they should retrieved and autotransplanted to save the patients from a permanent hypoparathyroidism when they undergo second surgery in future, and 2) hemithyroidectomy with bilateral central dissection significantly increases the risk of permanent hypoparathyroidism and only ipsilateral dissection is better when we do not perform total thyroidectomy.

Risk factors of hypoparathyroidism following total thyroidectomy for thyroid cancer

BACKGROUND

The risk factors responsible for hypoparathyroidism after total thyroidectomy have not been completely defined. The present study evaluated one surgeon's personal experience of postoperative hypoparathyroidism after total thyroidectomy for thyroid cancer and predisposing risk factors of postoperative hypoparathyroidism.

METHODS

We performed a retrospective analysis of 531 consecutive total thyroidectomy cases for thyroid cancer operated by single surgeon at the Center for Thyroid Cancer, National Cancer Center, Korea, from March 2003 to August 2006.

RESULTS

Postoperative hypoparathyroidism occurred in 135 patients (25.4 %), 19 of whom (3.6 % of total patients) experienced permanent hypoparathyroidism. Parathyroid autotransplantation, bilateral central lymph node dissection, gross extrathyroidal extension, and the presence of parathyroid gland in the pathologic specimen were associated with postoperative hypoparathyroidism in multivariate analysis (p < 0.05, respectively). The presence of parathyroid gland in the pathologic specimen and the early period of surgeon's practice were statistically significant risk factors for permanent hypoparathyroidism in multivariate analysis (p < 0.05, respectively).

CONCLUSIONS

Careful surgical technique for in situ preservation of parathyroid gland and autotransplantation of inadvertently removed parathyroid gland are important, especially in case of gross extrathyroidal extension. Adequate surgical experience is also an important factor. And routine bilateral central lymph node dissection should be done thoughtfully for its effect on postoperative hypoparathyroidism.

Impact of preserving the parathyroid glands on hypocalcemia after total thyroidectomy with neck dissection

PURPOSE

The aims of this study were to determine the incidence and evaluate the risk factors for hypocalcemia after total thyroidectomy and to investigate how many parathyroid glands should be preserved to prevent postoperative hypocalcemia.

METHODS

From March 2007 to February 2011, a retrospective review of 866 patients who underwent total thyroidectomy and node dissection for thyroid cancer was performed. The incidence and predisposing factors for hypocalcemia were analyzed. Among them, a total of 191 cases had four of their parathyroid glands identified intraoperatively. These patients were then divided into one preserved parathyroid gland group (group I, n = 22) and two or more preserved parathyroid glands group (group II, n = 169). The incidence of hypocalcemia with regards to the number of preserved parathyroid glands was determined and the results between the two groups were compared. The total calcium, ionized calcium and parathyroid hormone levels were compared between the two groups.

RESULTS

The overall incidence of transient and permanent hypocalcemia was 9.2% and 0.5%, respectively. The decreased number of preserved parathyroid gland and increased number of removed central lymph node were the significant risk factors for developing postoperative hypocalcemia. In 191 cases identified with four parathyroid glands, the incidence of hypocalcemia was related to the number of preserved glands (group I, 22.7%; group II, 3.0%; P < 0.001).

CONCLUSION

The insufficient number of preserved parathyroid glands is the only cause of hypocalcemia after total thyroidectomy and node dissection. At least one preserved parathyroid gland may prevent postoperative permanent hypocalcemia.

Serum intact parathyroid hormone level after total thyroidectomy or total thyroidectomy plus lymph node dissection for thyroid nodules: report from 296 surgical cases

BACKGROUND

Transient hypocalcemia is one of the postoperative complications of thyroidectomy for thyroid nodules, and intraoperative and postoperative intact parathyroid hormone (iPTH) assays are used to predict postoperative hypocalcemia.

OBJECTIVES

The current study was conducted to evaluate a single serum iPTH measurement on postoperative day 1 (POD 1) as a means to predict hypocalcemia occurrence after total thyroidectomy (TT).

PATIENTS AND METHODS

The subjects consisted of 36 patients who underwent TT and 260 patients who underwent TT plus lymph node (LN) dissection for thyroid nodules treatment. The TT performance procedure to prevent postoperative hypoparathyroidism combines parathyroid gland preservation in situ with autotransplantation of resected or devascularized parathyroid glands. The patients' serum iPTH level was measured on POD 1, and their serum calcium level was measured on POD 1 and on POD 3 while they were still inpatients. The serum iPTH level was subequently measured at each outpatient clinic visit until it recovered to the normal range.

RESULTS

Hypoparathyroidism after TT and TT plus LN dissection was ultimately diagnosed in a total of 229 patients, and in 69 of them hypocalcemia was diagnosed on POD 1. All of the 69 patients diagnosed with hypocalcemia received calcium and vitamin D supplementation therapy. The serum iPTH level of 67 of 229 patients was within normal range on POD 1, and four of them developed hypocalcemia on POD 1. Permanent hypoparathyroidism developed in 37 of 296 patients after undergoing TT or TT plus LN dissection for thyroid nodules in the hospital.

CONCLUSIONS

A single serum iPTH measurement on POD 1 is useful to determine whether or not to start calcium and vitamin D supplementation in order to maintain normocalcemia after surgery.

Intra- and postoperative parathyroid hormone-kinetics do not advocate for autotransplantation of discolored parathyroid glands during thyroidectomy

BACKGROUND

Thyroidectomy continues to pose the risk of typical complications, including postoperative hypocalcemia and permanent hypoparathyroidism. The strategic decision on how to preserve parathyroid hormone (PTH) secretion relies on assessing the viability of the parathyroid glands (PGs). The aim of this study was to assess parathyroid discoloration as an indicator for loss of parathyroid function.

METHODS

The prospective study included 29 patients (24 women, 5 men; age 53.2 ± 13.0 years) who underwent near-total or total thyroidectomy. An intra- and postoperative PTH and calcium monitoring was performed. The intraoperative situs of the PGs was documented by a study protocol. The patients were grouped in three categories: group A, 12 patients with four visualized and normally colored PGs; group B, 13 patients with four visualized and three or four discolored PGs; group C, 4 patients who had undergone autotransplantation of two PGs.

RESULTS

Compared to group A, groups B and C showed sharper intraoperative PTH declines. PTH values recovered more quickly in group B than in group C. However, no significant differences in PTH kinetics were found in the general linear model for repeated measures (p = 0.132). However, a significantly higher incidence of protracted hypocalcemia-related symptoms for more than 14 postoperative days was found for group C (50.0%) than for groups A (0%) and B (0%; p = 0.011). None of the patients developed permanent hypoparathyroidism.

CONCLUSIONS

The function of discolored PGs is only transiently impaired and recovers within a short time after surgery. Our observations do not support autotransplantation as a generally applicable first-line intervention for discolored PGs in the absence of other criteria for autotransplantation.

Intra-operative parathyroid hormone monitoring in secondary hyperparathyroidism: is it useful?

OBJECTIVES

To assess the use of intra-operative parathyroid hormone (PTH) level monitoring as a predictor of persistent hypoparathyroidism after total parathyroidectomy in renal hyperparathyroidism.

SETTING

University Teaching Hospital Otorhinolaryngology and Head and Neck Surgery Unit.

PARTICIPANTS

All patients with renal hyperparathyroidism undergoing parathyroidectomy between January 2004 and July 2005. Twenty-nine patients were identified.

MAIN OUTCOME MEASURES

Comparison is made between pre- and intra-operative PTH levels (ioPTH) in patients who at 3 months postoperatively maintained hypoparathyroidism and patients who did not. Results were analysed to see whether ioPTH predicts maintenance of the hypoparathyroid state.

RESULTS

The mean preoperative PTH level was 932 pg/L (range: 58-1808). The mean postoperative PTH level was 147 pg/L (range: 16-498). The mean 3-month PTH level was 47 pg/L (range: <1-515). The mean postoperative PTH level for patients with a persistently high PTH level at 3 months was 286 pg/L (range: 272-299), compared with 63 pg/mL (16-160) in patients remaining normparathyroid, and 159 pg/L (range: 39-498) for patients with persistent hypoparathyroidism. If the normoparathyroid state is strictly considered to be failure following total parathyroidectomy, ioPTH is not predictive of hypoparathyroidism. However, ioPTH is indicative of biochemical resolution of the hyperparathyroid state (normo- or hypoparathyroidism).

CONCLUSION

We conclude that the use of ioPTH monitoring in the surgical management of secondary hyperparathyroidism fails to predict persistent hypoparathyroidism following total parathyroidectomy, but does predict biochemical resolution of hyperparathyroidism.

Recovery of parathyroid function after total thyroidectomy: Long-term follow-up study

BACKGROUND

To prevent postoperative hypoparathyroidism following total thyroidectomy, the parathyroid glands are preserved in situ and/or resected or devascularized parathyroid glands are autotransplanted. A retrospective investigation was conducted utilizing biochemical and specific endocrine assessments to evaluate the difference in recovery of parathyroid function in the long term.

METHODS

A total of 103 patients underwent total thyroidectomy at Second Department of Surgery, School of Medicine, Kagawa University between 1990 and 1998. These patients were divided into a preservation group (n = 17), with only preserved glands in situ; a combination group (n = 72), consisting of patients with one or more parathyroid glands preserved in situ and one or more autotransplanted parathyroid glands; and an autotransplantation group (n = 14), with only transplanted glands.

RESULTS

The overall incidence of permanent hypoparathyroidism in the preservation group, the combination group, and the autotransplantation group was 0%, 1.4%, and 21.4%, respectively. The mean levels of intact parathyroid hormone in the preservation group, the combination group, and the autotransplantation group recovered to 102%, 107%, and 50% of the preoperative levels at 5-year follow up.

CONCLUSION

The results of the present study suggest that parathyroid glands should be preserved in situ whenever possible, to promote better recovery of postoperative function, and that only autotransplantation produces inadequate recovery of long-term function.

Should Female Patients Undergoing Parathyroid-Sparing Total Thyroidectomy Receive Routine Prophylaxis for Transient Hypocalcemia?

Hypocalcemia following parathyroid-sparing total thyroidectomy is frequent and can prolong hospital stay. We undertook this study to identify preoperative predictors of postoperative hypocalcemia useful in the postoperative management of these patients. We examined patients undergoing total thyroidectomy for benign disease with preservation of at least three parathyroids from January 2000 to January 2001. Low serum calcium was considered below 8.0 mg/dL. Age, gender, preoperative serum calcium, thyroid stimulating hormone (TSH), T3, T4, albumin, cholesterol, and tryglicerides were compared in patients with normal and low serum calcium level on the second postoperative day and on discharge day by using χ2 test and a model of logistic regression. Data were reported using their frequency distribution among the two groups of patients. Eighty patients, 60 females (F) and 20 males (M), underwent parathyroid-sparing total thyroidectomy. On second postoperative day, hypocalcemia occurred in 42 patients, and 56 per cent were symptomatic. Only female gender (88% F vs 12% M) ( P < 0.05) and TSH <0.27 mUI/mL (38% vs 18%) ( P < 0.05) predicted hypocalcemia. Similarly, female gender predicted hypocalcemia in a logistic regression analysis ( P < 0.05). On the day of discharge, 22 patients had low serum calcium levels, and 50 per cent were symptomatic. At this time, only TSH value <0.27 mlU/mL significantly predicted hypocalcemia (48% vs 17%) ( P < 0.05). This was confirmed in a logistic regression analysis ( P < 0.05). All but one patient (98%) eventually returned to normal serum calium levels. Despite preservation of parathyroids, transient symptomatic hypocalcemia is common after total thyroidectomy. Female gender and low TSH serum level predicted hypocalcemia. Therefore, female patients undergoing total thyroidectomy with preoperative low TSH levels should receive calcium prophylaxis to decrease morbidity, shorten hospital stay, and decrease costs.

Multiple endocrine neoplasia type 2a (MEN2a): a call for psycho-social research

This paper summarizes what is known about the diagnosis, treatment, and follow-care of people with the inherited disorder multiple endocrine neoplasia type 2a (MEN2a). Several databases were searched throughout the year 2000, including MEDLINE, CINAHL, CancerLit, PsychINFO, and Dissertation Abstracts International. MEN2a is a complex disease involving cancer care and control by surgery, health maintenance, and life-long observation of gene mutation carriers. Genetic testing is the standard of care, prophylactic surgery is recommended during directive counseling, and life-long surveillance is encouraged for people with MEN2a. A substantial body of scientific literature describes morbidity and mortality outcomes of disease treatment, and the monitoring of multiple organ systems. Research is scant concerning the psychological consequences and social impact of the MEN2a diagnosis, treatment, and follow-up. Nearly all that is known from a psycho-social perspective comes from data in The Netherlands. Little is known of the psychological responses to and social consequences of genetic predisposition testing, prophylactic and curative surgery, and life-long surveillance. Psycho-social research is essential to provide comprehensive care for patients and family members with this disorder and it is necessary to guide the development of risk management strategies for patients with this inherited cancer syndrome. Since MEN2a has been labeled a prototype for medical genetics, information on MEN2a patient experiences may be relevant to the care of individuals with other inherited cancer syndromes.