Validating the risk of hypoparathyroidism after total thyroidectomy in a population-based cohort: plea for improved follow-up

Patients With Persistent Hashimoto-Related Symptoms. Dilemmas in Advice-Giving and Self-Selection for Thyroidectomy. An Observational Study

OBJECTIVE

Some Hashimoto-related symptoms, persistent despite medically obtained euthyroidism, are believed to be related to autoimmunity. Total thyroidectomy has proved beneficial for patient-reported outcome measures (PROMs), but with a certain risk of complications. Selection criteria for surgery have not been defined. Molecular evidence supporting an autoimmune cause is lacking, and a placebo effect of surgery cannot be excluded. Short of selection criteria for thyroidectomy and no pathophysiologic model to adequately explain persistent symptoms, we wanted to look into factors that may be related to patients' decision for surgery, thus aiming to facilitate patient-physician communication on treatment for persistent Hashimoto-related symptoms.

METHODS

A total of 177 patients with persistent Hashimoto disease-related symptoms and highly motivated for thyroidectomy completed an 18-month watchful waiting period with biannual consultations before being offered thyroidectomy. PROMs were monitored before and after surgery.

RESULTS

After 18 months of watchful waiting, 131 (74%) of 177 patients proceeded to thyroidectomy whereas 46 declined surgery. There was no difference between the surgery and no-surgery groups regarding sex, age, and thyroid peroxidase antibody levels at 18 months watchful waiting. Compared with the no-surgery group, PROM scores were consistently poorer in the surgery group for all domains in the PROM questionnaires used.

CONCLUSIONS

A grace period of 18 months with biannual follow-up before thyroidectomy may be useful to modify exposure to surgery carrying a certain risk of complications. At 18 months, the fatigue score stands out as the most important factor influencing the odds for maintaining a choice to have surgery.

Utility of Parathyroid Autofluorescence in Differentiating Parathyroid Pathology

BACKGROUND

Near-infrared autofluorescence (NIRAF) spectroscopy is an emerging adjunct for intraoperative parathyroid identification. However, its ability to differentiate between normocellular, hyperplastic, or adenomatous parathyroids remains unexplored. We hypothesize that parathyroid adenomas have lower NIRAF ratios than normocellular parathyroids since the likely fluorophore is the calcium-sensing receptor (CaSR), which is downregulated in adenomas.

METHODS

In vivo NIRAF ratios for each identified parathyroid gland were recorded for patients undergoing thyroidectomy or parathyroidectomy from 08/2023 to 12/2023 at a single institution. Parathyroids were categorized as normocellular by visual inspection and hyperplastic or adenomatous by final histology.

RESULTS

Of the 44 patients included (66% underwent parathyroidectomy and 34% underwent thyroidectomy), 137 parathyroids were identified intraoperatively with 66 resected and analyzed histologically. A total of 71 (52%) parathyroids were normocellular, 45 (33%) were hyperplastic, and 21 (15%) were adenomatous. Among the resected parathyroids, there was moderate agreement (81%) between visual categorization and final histology for hyperplasia versus adenoma (κ = 0.6). Parathyroid adenomas had lower median NIRAF ratios than normocellular parathyroids (p = 0.0005). Median NIRAF ratios were not significantly different between normocellular and hyperplastic parathyroids (p = 0.35) nor between hyperplastic parathyroids and adenomas (p = 0.04). The performance of NIRAF spectroscopy in differentiating parathyroid pathology is poor based on receiver operator characteristics analysis.

CONCLUSION

Parathyroid adenomas have lower NIRAF ratios than normocellular parathyroids. However, the performance of using NIRAF ratios to differentiate between parathyroid pathology is poor. Therefore, the differences in NIRAF ratios are unlikely to be sufficient at point-of-care use to distinguish between various parathyroid pathologies. As NIRAF ratios are highest in normocellular parathyroid glands, NIRAF appears to be most useful in detecting normal parathyroid glands.

Development and validation of risk prediction models for permanent hypocalcemia after total thyroidectomy in patients with papillary thyroid carcinoma

Hypocalcemia is a common complication and can be permanent in patients following total thyroidectomy (TT). The aim of this study was to identify factors associated with permanent hypocalcemia and to develop a validated risk prediction model for permanent hypocalcemia to assist surgeons in the appropriate follow-up of high-risk patients regarding supplemental therapy. We included data of 92 patients with papillary thyroid carcinoma (PTC) undergoing TT who were randomly allocated in a 7:3 ratio to a training set (n = 65) and validation set (n = 27). Univariate and multivariate logistic regression analyses revealed significant correlations of permanent hypocalcemia with parathyroid hormone (PTH) at postoperative month 1 (IM PTH), IM calcium (Ca), and IM phosphorus (P). These variables were constructed two models. Model 1 used the three indicators listed above; model 2 also included tumor, node, metastasis staging. The receiver operating characteristic (ROC) curve analysis showed that the areas under the curve (AUC) for models 1 and 2 were high for both the training set (0.905/0.913) and the validation set (0.894/0.800). Calibration curves showed good agreement between the incidence of permanent hypocalcemia estimated using the predictive models and the actual incidence. Model 1 may be more concise and convenient for clinical use.

Treatment strategy for intermediate-risk papillary thyroid cancer: Focus on postoperative hypothyroidism following lobectomy

OBJECTIVE

An optimal surgical approach for intermediate-risk papillary thyroid cancer (PTC) has not yet been established. The surgical procedure should be determined based on treatment outcomes and postoperative complications. This study aimed to evaluate appropriate surgical strategies for patients with intermediate-risk PTC by comparing treatment outcomes and postoperative complications following total thyroidectomy and lobectomy.

METHODS

This retrospective analysis was conducted on 123 patients with intermediate-risk PTC treated in our department between January 2008 and December 2022. The risk of PTC was classified according to the 2024 Guidelines for the Clinical Treatment of Thyroid Nodules from the Japan Association of Endocrine Surgery.

RESULTS

Of the 123 patients, 27 underwent total thyroidectomy, and 96 underwent lobectomy. No significant differences were observed between the two surgical groups in terms of survival or recurrence rates. None of the patients showed bilateral recurrent laryngeal nerve (RLN) palsy postoperatively. Postoperative unilateral RLN palsy occurrence differed significantly between the total thyroidectomy and lobectomy groups, with five cases in each (5.2 and 18.5 %, respectively; p = 0.04). Permanent hypoparathyroidism was observed in two patients (7.4 %) in the total thyroidectomy group. Postoperative hypothyroidism developed in 42 (43.8 %) lobectomy cases, with 32 requiring the administration of levothyroxine therapy. A significant association was observed between preoperative thyroid-stimulating hormone (TSH) levels (≥2.0 μIU/mL) and postoperative hypothyroidism (p < 0.001).

CONCLUSION

No significant difference in treatment outcomes was observed between patients with intermediate-risk PTC who underwent total thyroidectomy and those who underwent lobectomy. In cases with preoperative TSH levels ≥2.0 μIU/mL, total thyroidectomy may be a more suitable approach, given the increased likelihood of requiring postoperative levothyroxine administration following lobectomy.

Utilization of recurrent laryngeal nerve monitoring during thyroid surgery in China: a point prevalence survey (2015-2023)

BACKGROUND

The survey aimed to elucidate the complete range of national practices, including all technical and non-technical aspects, as well as surgical stratification and maturation, of the use of intraoperative neuromonitoring (IONM) during thyroid surgery in China.

MATERIALS AND METHODS

Six national questionnaires, developed by the Chinese Neural Monitoring Study Group (CNMSG) between 2015 and 2023, were used to collect and analyze data regarding the clinical application, education, and scientific research related to IONM in Chinese medical institutions.

RESULTS

Among the surveyed hospitals, 45% reported an average annual surgical volume exceeding 3000 cases, with 82.5% performing more than 80% of the surgeries for malignant thyroid tumors. Additionally, 97.5% of the hospitals reported a less than 3% incidence of postoperative hoarseness with IONM. Statistical analysis from 2011 to 2015 found that the incidence of postoperative hoarseness decreased by 30% in 2013 compared with 2011, when the technology was introduced. Preoperative and postoperative laryngoscopies were routinely performed by 82.5% and 15% of the hospitals, respectively. For 65% of the hospitals, the publication of the Chinese edition of neuromonitoring guidelines in 2013 prompted the utilization of IONM technology. An average annual number of IONM applications exceeding 500 cases (18.5% the average volume) was reported by 80% of the hospitals, while 62.5% reported a cumulative number of applications greater than 5000 cases (47.1% the average cumulative volume). Regarding technical parameters, 75% of the hospitals reported an intraoperative V1 amplitude of greater than 500 µV, and 70% reported an intraoperative loss of signal (LOS) rate of less than 3%. 92.5% of the surveyed hospitals believed that IONM could help identify dissociated nerves, and 95% of the surveyed hospitals believed that IONM could reduce nerve damage. However, 72.5% of the respondents thought that cost was the main limitation. Furthermore, 67.5% of the hospitals reported that half of their thyroid surgical team members were trained in IONM, with 17.5% reporting that all team members were trained. Areas for reinforced training included IONM research methods and directions (72.5%) and analysis and treatment of abnormal EMG signals (72.5%). Research projects related to IONM were conducted by 42.5% of the hospitals, while 52.5% had published papers on neuromonitoring.

CONCLUSIONS

IONM was independently and incrementally associated with the annual surgical volume. This survey emphasized the importance of national collaboration and/or a registry for the uptake, consolidation, and development of CNMSG consensus.

Prevalence of chronic postsurgical hypoparathyroidism not adequately controlled: an analysis of a nationwide cohort of 337 patients

Purpose

The identification of patients with chronic hypoparathyroidism who are adequately (AC) or not adequately controlled (NAC) has clinical interest, since poor disease control is related to complications and mortality. We aimed to assess the prevalence of NAC patients in a cohort of subjects with postsurgical hypoparathyroidism.

Methods

We performed a multicenter, retrospective, cohort study including patients from 16 Spanish hospitals with chronic hypoparathyroidism lasting ≥3 years. We analyzed disease control including biochemical profile and clinical wellness. For biochemical assessment we considered three criteria: criterion 1, normal serum calcium, phosphorus and calcium x phosphorus product; criterion 2, the above plus estimated glomerular filtration rate ≥60 ml/min/1.73 m2; and criterion 3, the above plus normal 24-hour urinary calcium excretion. A patient was considered AC if he or she met the biochemical criteria and was clinically well.

Results

We included 337 patients with postsurgical hypoparathyroidism (84.3% women, median age 45[36-56] years, median time of follow-up 8.9[6.0-13.0] years). The proportions of NAC patients with criteria 1, 2 and 3 were, respectively, 45.9%, 49.2% and 63.1%. Patients who had dyslipidemia at the time of diagnosis presented a significantly higher risk of NAC disease (criterion 3; OR 7.05[1.44-34.45]; P=0.016). NAC patients (criterion 2) had a higher proportion of subjects with incident chronic kidney disease and eye disorders, and NAC patients (criterion 3) had a higher proportion of incident chronic kidney disease, nephrolithiasis and dyslipidemia than AC patients.

Conclusion

The present study shows a strikingly high prevalence of NAC patients in the clinical practice of Spanish endocrinologists. Results suggest that NAC disease might be associated with some prevalent and incident comorbidities.

Risk factors of transient and permanent hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Postoperative hypoparathyroidism (hypoPT) is a common complication following thyroid surgery. However, current research findings on the risk factors for post-thyroid surgery hypoPT are not entirely consistent, and the same risk factors may have different impacts on transient and permanent hypoPT. Therefore, there is a need for a comprehensive study to summarize and explore the risk factors for both transient and permanent hypoPT after thyroid surgery.

MATERIALS AND METHODS

Two databases (PubMed and Embase) were searched from inception to 2024. The Newcastle-Ottawa Scale was used to rate study quality. Pooled odds ratios were used to calculate the relationship of each risk factor with transient and permanent hypoPT. Subgroup analyses were conducted for hypoPT with different definition-time (6 or 12 months). Publication bias was assessed using Begg's test and Egger's test.

RESULTS

A total of 19 risk factors from the 93 studies were included in the analysis. Among them, sex and parathyroid autotransplantation were the most frequently reported risk factors. Meta-analysis demonstrated that sex (female vs. male), cN stage, central neck dissection, lateral neck dissection, extent of central neck dissection (bilateral vs. unilateral), surgery [total thyroidectomy (TT) vs. lobectomy], surgery type (TT vs. sub-TT), incidental parathyroidectomy, and pathology (cancer vs. benign) were significantly associated with transient and permanent hypoPT. Preoperative calcium and parathyroid autotransplantation were only identified as risk factors for transient hypoPT, while preoperative PTH was a protective factor. Additionally, node metastasis and parathyroid in specimen were associated with permanent hypoPT.

CONCLUSION

The highest risk of hypoPT occurs in female thyroid cancer patients with lymph node metastasis undergoing TT combined with neck dissection. The key to preventing postoperative hypoPT lies in the selection of surgical approach and intraoperative protection.

Delayed cervical emphysema after thyroidectomy: a case report and a literature overview

Thyroidectomy is a surgery performed due to both benign and malign diseases in the thyroid. The overall complication rate is low, where most of them will appear within the first 24 hours after surgery. However, severe complications can occur as late as 14 days postsurgery. A woman in her late 30's underwent total thyroidectomy due to Graves' disease. There were no complications until she presented with swelling on her neck 10 days after surgery. She was diagnosed with cervical emphysema and treated with a controlled negative pressure drain until there was no more air leakage. We assumed that the emphysema was due to an occult injury of the trachea. Urgent evaluation and hospitalization are needed if the patient presents with swelling in the neck after thyroidectomy. Surgeons should be aware of this delayed complication, so they are able to inform and manage their patients accordingly.

Hypoparathyroidism and mortality after total thyroidectomy: A nationwide matched cohort study

OBJECTIVE

Total thyroidectomy (TT) carries a risk of hypoparathyroidism (hypoPT). Recently, hypoPT has been associated with higher overall mortality rates. We aimed to evaluate the frequency of hypoPT and mortality in patients undergoing TT in Denmark covering 20 years.

DESIGN

Retrospective Cohort study.

PATIENTS AND MEASUREMENTS

Using population-based registries, we identified all Danish individuals who had undergone TT between January 1998 and December 2017. We included a comparison cohort by randomly selecting 10 citizens for each patient, matched on sex and birth year. HypoPT was defined as treatment with active vitamin D after 12 months postoperatively. We used cumulative incidence to calculate risks and Cox regression to compare the rate of mortality between patients and the comparison cohort. We evaluated patients in different comorbidity groups using the Charlson Comorbidity Index and by different indications for surgery.

RESULTS

7912 patients underwent TT in the period. The prevalence of hypoPT in the study period was 16.6%, 12 months postoperatively. After adjusting for potential confounders the risk of death due to any causes (hazard ratio; 95% confidence intervals) following TT was significantly increased (1.34; 1.15-1.56) for patients who developed hypoPT. However, subgroup analysis revealed mortality was only increased in malignancy cases (2.48; 1.99-3.10) whereas mortality was not increased when surgery was due to benign indications such as goitre (0.88; 0.68-1.15) or thyrotoxicosis (0.86; 0.57-1.28).

CONCLUSIONS

The use of active vitamin D for hypoPT was prevalent one year after TT. Patients with hypoPT did not have an increased risk of mortality following TT unless the indication was due to malignancy.