Risk Factors for Hypoparathyroidism after Thyroid Surgery: A Single-Center Study

Prognostic implications of lymph node yield in pediatric patients with N1b papillary thyroid cancer

OBJECTIVE

To investigate whether lymph node (LN) yield influences clinical outcomes for pediatric patients with laterocervical lymph node metastasis (N1b) from papillary thyroid cancer (PTC).

METHODS

Conducted from January 1, 2008, to December 31, 2022, this was a cohort study of pediatric patients (aged ≤ 18 years) with N1b PTC who underwent total thyroidectomy and therapeutic LN dissection in the central and lateral compartments at 3 hospitals in southwest China in 2008-2021, with follow-up until 2022. Patients with distant metastasis were excluded. Univariate and multivariate Cox proportional hazards regression analyses were used to identify factors associated with persistent/recurrent diseases.

RESULTS

A total of 102 pediatric patients (median [range] age, 16 [6-18] years) were analyzed: 36 patients (35 %) with T1; 27 patients (26 %), T2; 18 patients (18 %), T3; and 21 patients (21 %), T4. During a median follow-up of 50 months (range, 12-154 months), persistent diseases occurred in 40 (39 %) patients. Receiver operating characteristic analysis identified LN yield cut-off (<42 LNs) to predict persistent diseases. Multivariate analysis revealed that a less-extensive lymphadenectomy (<42 LNs) was an independent risk factor for persistent diseases (hazard ratio, 2.4; 95 % confidence intervals, 1.09-5.29; P=.029).

CONCLUSIONS

Our study highlights that a higher LN yield may favorably influence prognosis in pediatric patients with N1b PTC.

Incidental Parathyroidectomy After Thyroid Surgery: A Single-Center Study

BACKGROUND

Hypoparathyroidism with hypocalcemia is the most frequent complication after thyroid surgery. Many risk factors have been involved in the development of this complication, with conflicting results. Incidental parathyroidectomy (IP) may be a frequent cause of postoperative hypocalcemia. In this study, we have evaluated the risk factors associated with the IP in a single-center cohort of patients undergoing thyroid surgery.

PATIENTS AND METHODS

The incidence and the risk factors for IP were evaluated in 799 patients scheduled for surgical treatment for thyroid disease between January 2018 and December 2023. Parathyroid hormone levels and serum calcium levels, together with the histological specimens, were evaluated in all patients.

RESULTS

Post-operative temporary hypocalcemia was present in 239 (29.9%) patients. A total of 144 patients (21.9%) had an incidental parathyroidectomy. Younger patients (<40 years) had the highest risk of having an incidental parathyroidectomy (RR 1.53 (95% CI 1.084-2.161), OR 1.72 (95% CI 1.091-2.710), p = 0.014). Moreover, thyroid cancer (RR 1.4 (95 CI 1.114-1.882) OR 1.68 (95% CI 1.145-2.484), p < 0.05) and the neck dissection (RR 1.75 (95% CI 1.409-2.198) OR 2.38 (95% CI 1.644-3.460), p < 0.001) were strongly associated with the risk of incidental parathyroidectomy.

CONCLUSIONS

Younger female patients with thyroid cancer and neck dissection were at the highest risk of incidental parathyroidectomy. A meticulous surgical dissection, together with imaging methods for the detection of the parathyroid glands, may reduce the incidence of this complication.

Hypoparathyroidism after total thyroidectomy: reactive to symptoms supplementation

INTRODUCTION

After total thyroidectomy (TT), postoperative hypoparathyroidism (PH) is the most frequent complication. Yet, management strategies for PH remain disputed. The aim of this study was to evaluate outcomes of a reactive supplementation in case of symptomatic PH. Additionally, risk factors for symptomatic PH and readmission due to PH were analyzed.

MATERIALS AND METHODS

All consecutive patients who underwent TT or completion from 2017 to 2022 were considered for inclusion. During this period, a reactive to symptom vitamin-calcium supplementation was used. The primary outcome was the occurrence of severe PH after discharge resulting in readmission.

RESULTS

Overall, 307 patients were included, of which 98 patients (31.9%) developed symptomatic PH including 43 patients before discharge. Independent risk factors for developing symptomatic PH were age (p = 0.010) and postoperative day 1 (POD1) PTH level (p < 0.001). Overall, 264 patients (86%) did not present PH before discharge and were discharged home. Among them, 55 patients (20.8%) experienced symptomatic PH, requiring readmission in 18 patients. The overall readmission rate owing to symptomatic PH requiring intravenous supplementation despite oral vitamin-calcium supplementation was 6.8% (n = 18). Independent risk factors for symptomatic PH-related readmission were age (p = 0.007) and POD1 PTH level (p < 0.001). Adequate cut-off values for predicting readmission were POD1 albumin-adjusted calcium = 2.1 mmol/l (Sensibility = 0.95, Specificity = 0.30) and POD1 PTH = 11.5 pg/ml (Sensibility = 0.90, Specificity = 0.71).

CONCLUSION

Supplementing only symptomatic patients was safe and efficient. This attitude does not alter on morbidity, mortality or readmission rate which is in line with current literature.

Risk Factors for Transient and Permanent Hypoparathyroidism Following Thyroidectomy: A Comprehensive Review

Hypoparathyroidism is a common complication following thyroidectomy, resulting in significant disturbances in calcium homeostasis due to low parathyroid hormone (PTH) levels. This comprehensive review examines the risk factors associated with transient and permanent hypoparathyroidism post-thyroidectomy, emphasizing surgical, patient-related, and perioperative factors. Transient hypoparathyroidism, characterized by temporary hypocalcemia resolving within weeks to months, is often managed with short-term calcium and vitamin D supplementation. In contrast, permanent hypoparathyroidism persists beyond six months post-surgery, necessitating lifelong supplementation and potentially PTH replacement therapy. The review delves into the anatomy and physiology of the parathyroid glands, mechanisms leading to hypoparathyroidism, and incidence rates. Surgical factors such as the extent of thyroidectomy, surgeon expertise, and intraoperative parathyroid gland preservation are critical in determining the risk of hypoparathyroidism. Patient factors, including age, sex, pre-existing conditions, and perioperative management, influence outcomes. Diagnostic and monitoring strategies, along with management protocols for both transient and permanent hypoparathyroidism, are discussed. Prevention strategies, emerging research, future surgical techniques, and intraoperative monitoring directions are highlighted to improve clinical outcomes. This review aims to enhance understanding, inform surgical practices, and optimize postoperative care to minimize the incidence and impact of hypoparathyroidism in thyroidectomy patients.

Iatrogenic Hypoparathyroidism Development After Thyroidectomy: A Retrospective Cohort Study

BACKGROUND

Iatrogenic hypoparathyroidism is a common cause of postthyroidectomy hypocalcaemia. It has varying incidence rates after neck surgery in Saudi Arabia, ranging from 0.07% to 65.30%. Hypoparathyroidism can manifest with a spectrum of symptoms, ranging from mild to severe and life-threatening. This study aimed to assess the rate and predictors of iatrogenic hypoparathyroidism after thyroid surgery and its natural course.

METHODS

This retrospective cohort study used a data collection form to extract patient information from the electronic healthcare system (Best-Care) for patients treated from 2017 to 2022. Patients' demographics, surgical specifics and biochemical profiles were recorded for subsequent analysis.

RESULTS

Among the 343 patients who underwent thyroidectomy, 130 (37.9%) developed hypoparathyroidism, primarily within the first day after surgery. Calcium or vitamin D supplementation before surgery did not significantly influence hypoparathyroidism development. Notably, extensive combined lymph node dissection was significantly associated with postoperative hypoparathyroidism development (p = 0.0004). More patients who underwent central and lateral lymph node dissection (n = 19, 79.17%) developed hypoparathyroidism than patients who underwent central (n = 18, 40.91%) or lateral (n = 8, 38.10%) dissection alone. Permanent hypoparathyroidism was observed in 40 patients (11.66%).

CONCLUSION

This study revealed a high incidence of iatrogenic hypoparathyroidism and high rates of permanent hypoparathyroidism. Further research is warranted to better comprehend the risk factors and optimise management strategies for iatrogenic hypoparathyroidism. Overall, our findings emphasise the need for vigilant monitoring and effective management of patients undergoing thyroidectomy and the significance of postoperative replacement therapies.

Risk Factors for Transient Hypoparathyroidism after Total Thyroidectomy: Insights from a Cohort Analysis

Background: Transient hypoparathyroidism (TH) is the main post-thyroidectomy complication, significantly impacting surgical outcomes, hospitalization length, and perceived perceived quality of life understood as mental and physical well-being. This study aims to identify possible associated risk factors. Methods: We analyzed 238 thyroidectomies (2020-2022), excluding instances of partial surgery, primary hyperparathyroidism, neck irradiation history, and renal failure. The variables considered were as follows: demographics, histology, autoimmunity, thyroid function, pre- and postoperative Vitamin D levels (where available), type of surgery, number of incidentally removed parathyroid glands (IRP), and surgeons' experience (>1000 thyroidectomies, <500, in training). Univariate analysis applied: χ2, Fisher's exact test for categorical variables, and Student's t-test for continuous variables. Subsequently, logistic multivariate analysis with stepwise selection was performed. Results: Univariate analysis did not yield statistically significant results for the considered variables. The 'No Complications' group displayed a mean age of 55 years, whereas the TH group showed a mean age of 51 (p-value = 0.055). We considered this result to be marginally significant. Subsequently, we constructed a multivariate logistic model. This model (AIC = 245.02) indicated that the absence of incidental parathyroidectomy was associated with the age class >55 years, presenting an odds ratio (OR) of 9.015 (p-value < 0.05). Simultaneously, the age class >55 years exhibited protective effects against TH, demonstrating an OR of 0.085 (p-value < 0.01). Similarly, the absence of incidental parathyroidectomy was found to be protective against TH, with an OR of 0.208 (p-value < 0.01). Conclusions: Multivariate analysis highlighted that having "No IRP" was protective against TH, while younger age was a risk factor. Surgeon experience does not seem to correlate with IRP or outcomes, assuming there is adequate tutoring and a case volume close to 500 to ensure good results. The effect of reimplantation has not been evident in transient hypoparathyroidism.

Interpretable machine learning model based on the systemic inflammation response index and ultrasound features can predict central lymph node metastasis in cN0T1-T2 papillary thyroid carcinoma

Background

It is arguable whether individuals with T1-T2 papillary thyroid cancer (PTC) who have a clinically negative (cN0) diagnosis should undergo prophylactic central lymph node dissection (pCLND) on a routine basis. Many inflammatory indices, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune-inflammatory index (SII), have been reported in PTC. However, the associations between the systemic inflammation response index (SIRI) and the risk of central lymph node metastasis (CLNM) remain unclear.

Methods

Retrospective research involving 1,394 individuals with cN0T1-T2 PTC was carried out, and the included patients were randomly allocated into training (70%) and testing (30%) subgroups. The preoperative inflammatory indices and ultrasound (US) features were used to train the models. To assess the forecasting factors as well as drawing nomograms, the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were utilized. Then eight interpretable models based on machine learning (ML) algorithms were constructed, including decision tree (DT), K-nearest neighbor (KNN), support vector machine (SVM), artificial neural network (ANN), random forest (RF), extreme gradient boosting (XGBoost), light gradient boosting machine (LightGBM), and categorical boosting (CatBoost). The performance of the models was evaluated by incorporating the area under the precision-recall curve (auPR) and the area under the receiver operating characteristic curve (auROC), as well as other conventional metrics. The interpretability of the optimum model was illustrated via the shapley additive explanations (SHAP) approach.

Results

Younger age, larger tumor size, capsular invasion, location (lower and isthmus), unclear margin, microcalcifications, color Doppler flow imaging (CDFI) blood flow, and higher SIRI (≥0.77) were independent positive predictors of CLNM, whereas female sex and Hashimoto thyroiditis were independent negative predictors, and nomograms were subsequently constructed. Taking into account both the auROC and auPR, the RF algorithm showed the best performance, and superiority to XGBoost, CatBoost and ANN. In addition, the role of key variables was visualized in the SHAP plot.

Conclusions

An interpretable ML model based on the SIRI and US features can be used to predict CLNM in individuals with cN0T1-T2 PTC.