Modification, validation and implementation of a protocol for post-thyroidectomy hypocalcaemia

Postoperative parathyroid hormone (PTH) is equivalent to perioperative PTH drop in predicting postsurgical hypoparathyroidism

INTRODUCTION

Postoperative surgical hypoparathyroidism (PoSH) following thyroid surgery is an established complication. Several predictive factors have been identified including perioperative parathyroid hormone (PTH) levels. The aim of the study is to compare the drop in perioperative PTH to postoperative day 1 PTH in predicting hypocalcaemia and hypoparathyroidism.

METHODS

Records of consecutive patients who had either total or completion thyroidectomy with or without central neck dissection in a 3-year period in a single thyroid surgery unit were accessed to retrieve data on demographics, pathology, surgery, perioperative biochemistry and management.

RESULTS

Of 295 included patients, there were 227 (76.9%) females. Forty-five (15.3%) had completion thyroidectomy, and the rest had total thyroidectomy. Seventy-eight (26.4%) had concomitant central neck dissection. Sixty-four (21.7%) had hypocalcaemia on the day after surgery. Hypoparathyroidism persisted in 10.5% of patients at 6 months. Both day 1 PTH and a drop in PTH predicted day 1 hypocalcaemia (p < 0.001) and 6-month hypoparathyroidism (p < 0.001). The area under the receiver operating characteristic (ROC) curves for day 1 PTH and drop in PTH for the prediction of day 1 hypocalcaemia (0.729 vs 0.726, respectively) and for 6-month hypoparathyroidism (0.964 vs 0.958, respectively) were similar, albeit slightly better for day 1 PTH.

CONCLUSIONS

Day 1 PTH is equivalent to (if not better than) drop in PTH in predicting short- and long-term PoSH. Preoperative PTH measurements may not be needed in the detection and/or management of PoSH after thyroid surgery.

Evaluation of Hypocalcemia Following Total Laryngectomy With and Without Thyroidectomy

OBJECTIVE

Hypoparathyroidism and associated hypocalcemia are well-established complications following laryngectomy. This study further characterizes the rates of hypocalcemia in patients undergoing total laryngectomy (TL) with and without thyroidectomy and hemithyroidectomy.

STUDY DESIGN

Retrospective cohort study.

SETTING

TriNetX.

METHODS

We queried TriNetX, a deidentified patient database, to identify patients who underwent TL with and without thyroidectomy and hemithyroidectomy. Rates of hypocalcemia, low parathyroid hormone (PTH), calcium, and calcitriol supplementation were compared between groups with multivariable repeated measures logistic regression.

RESULTS

We identified 870 patients in the TL without thyroidectomy cohort, 158 patients in the hemithyroidectomy cohort, and 123 in the total thyroidectomy cohort. Rates of hypocalcemia differed between patients receiving total thyroidectomy versus TL alone for 0 to 1 month (odds ratio [OR]: 2.88 [1.95-4.26]) 1 to 6 months (OR: 5.08 [2.29-11.3]), and 6 to 12 months (OR: 2.63 [1.003-6.88]) postoperatively, with adjustment for age at laryngectomy, race, ethnicity, and gender. Results were similar among those who received calcium supplementation. The rate of low PTH levels differed in these groups for 0 to 1 month (OR: 5.13 [3.10-8.51]), 1 to 6 months (OR: 3.47 [1.46-8.22]), and 6 to 12 months (OR: 3.63 [1.40-9.38]) following surgery. Rates of postoperative calcium supplementation were increased for patients receiving total thyroidectomy versus TL for 1 to 6 months (OR: 2.44 [1.62-3.68]), and 6 to 12 months following surgery (OR: 1.79 [1.18-2.72]).

CONCLUSION

Patients undergoing TL with total thyroidectomy have a higher risk of postoperative hypocalcemia compared to patients receiving TL alone. Risk of parathyroid injury in these patients may warrant further emphasis on PTH measurement after surgery and a multidisciplinary approach to management.

Management of hypocalcemia following thyroid surgery in children

Introduction

Pediatric post-thyroidectomy hypocalcemia management varies significantly from hospital to hospital. The current study has two aims: first, we evaluate demographic data in all pediatric patients submitted to thyroid surgery in our Spanish tertiary hospital over 20 years; secondly, we describe the way that hypocalcemia was diagnosed and treated in that period and present a multidisciplinary protocol for perioperative management of this condition.

Methods

This is a retrospective and observational study of all patients from 0 to 16 years old who underwent thyroid surgery from 2000 to 2020 at our institution. Demographic, surgical and electrolyte data were recorded from the electronic database.

Results

From 2000 to 2016, pediatric thyroid surgery at our institution was performed on 33 patients without a consistent approach or standard electrolyte management. A protocol for perioperative management of these patients was introduced in 2017, and applied to 13 patients. In 2019, the protocol was assessed and updated following a case of symptomatic hypocalcemia. From 2000 to 2016, 47 pediatric patients in all underwent thyroid surgery. We registered eight asymptomatic hypocalcemias. One child developed symptomatic hypocalcemia. Two patients have permanent hypoparathyroidism.

Discussion

Our incidence of general complications following thyroidectomy was low; hypocalcemia was the most prevalent. All the cases of hypocalcemia submitted to the protocol were identified early by iPTH measurements. Intraoperative iPTH levels and percentage drop from baseline could help stratify patients according to their risk of hypocalcemia. High risk patients require immediate postoperative supplementation, including calcitriol and calcium carbonate.

Evaluation of hypoparathyroidism following laryngectomy

BACKGROUND

Hypoparathyroidism is a recognised complication following laryngectomy; it is associated with significant short-and long-term morbidity. This study aimed to further characterise this condition, identify risk factors and describe preventative and management strategies in a large cohort.

MATERIALS AND METHODS

This was a retrospective study at a tertiary referral centre for head and neck cancers. All consecutive patients who had total laryngectomy over an eight-year period were included.

RESULTS

A total of 140 patients were included. Rates of transient and long-term hypoparathyroidism were 14.3% and 10.1%, respectively. The following factors were significantly associated with transient post-surgical hypocalcaemia or hypoparathyroidism: total thyroidectomy (relative risk, RR, 4.33; 95% confidence interval, CI, 1.86-10.10), oesophagectomy (RR 6.05; 95% CI 2.92-12.53) and female sex (RR 3.23; 95% CI 1.45-7.19). In addition, total thyroidectomy (RR 5.89; 95% CI 1.94-17.86), central neck dissection (RR 3.97; 95% CI 1.42-11.10), oesophagectomy (RR 9.38; 95% CI 4.13-21.3), pharyngectomy (RR 7.14; 95% CI 2.08-24.39) and female sex (RR 5.52; 95% CI 1.95-15.63) were risk factors for long-term hypoparathyroidism. There was variability in the use of preventative measures, monitoring and management of hypocalcaemia and hypoparathyroidism following total laryngectomy.

CONCLUSIONS

Transient hypocalcaemia and long-term hypoparathyroidism occur in a significant proportion of patients after laryngectomy. A standard protocol is required to improve care.

Parathyroid hormone of ≥1.6 pmol/L at 6 months is associated with recovery in 'long-term' post-surgical hypoparathyroidism

Objective

Post-surgical hypoparathyroidism (PoSH) usually settles within few months after thyroid surgery, but several patients require long-term supplementation with calcium/activated vitamin D. When PoSH persists beyond 6 months, it is considered 'chronic' or 'permanent', however, late recovery has been reported. The aim of this study was to determine the frequency of late recovery and explore factors predicting late recovery of parathyroid function.

Methods

Adult patients undergoing total/completion thyroidectomy between 2009 and 2018 were included in this retrospective cohort observational study. The records of patients with evidence of PoSH were reviewed to identify those with persisting PoSH at 6 months. Demographic, biochemical, surgical, pathological, and clinical follow-up data were collected and analysed.

Results

Out of 911 patients undergoing thyroidectomy, 270 were identified with PoSH. Of these, 192 were started on supplements and 138 (71.9%) recovered within 6 months. Of the remaining 54 patients, 35 had ongoing PoSH with median (range) follow-up of 3.4 (0.5-11.1) years. Nineteen patients were weaned off supplements and achieved remission at median (range) follow-up of 1.3 (0.6-4.8) years. All of those who recovered had a PTH of ≥1.6 pmol/L at 6 months. There was no difference in age, gender, diagnosis, type, and extent of surgery between those who did and did not show late recovery.

Conclusions

Recovery from PoSH is common beyond 6 months, raising the question whether a 6-month threshold to define 'long-term' PoSH is appropriate. The chances of recovery are high (~50%) in patients with PTH level ≥1.6 pmol/L at 6 months, where attempts at weaning may be focussed.

Risk factors for postoperative morbidity after thyroid surgery in a PROSPECTIVE cohort of 1500 patients

BACKGROUND

Postoperative hypocalcaemia, recurrent laryngeal nerve palsy and postoperative bleeding are the most frequent postoperative complications after thyroid surgery, and therefore often used as quality indicators of thyroid surgery. We aimed to assess postoperative morbidity in a high-volume endocrine surgery unit, and to detect which factors are associated with higher risks.

METHODS

Prospective surgical cohort in a high-volume tertiary referral centre for endocrine surgery in xxx. The first 1500 patients operated with hemi or total thyroidectomy during 2010-2019 were included. Postoperative hypocalcaemia, recurrent laryngeal nerve palsy and postoperative bleeding were assessed in relation to pre- and peri-operative characteristics using multivariable logistic regression analyses, expressed as odds ratios and 95% confidence intervals.

RESULTS

Overall, 1043 patients (69.5%) received a total thyroidectomy and 457 (30.5%) a hemithyroidectomy. Permanent hypocalcaemia occurred in 3.1%, permanent recurrent laryngeal nerve palsy in 1.8% and surgical reintervention for bleeding in 2.6%. Younger age, female sex and cancer were risk factors for permanent hypocalcaemia. No clear risk factors could be identified for permanent nerve palsy. Female sex, high body mass index and heavier thyroids were protective against postoperative bleeding after total thyroidectomy.

CONCLUSIONS

Surgical experience in endocrine surgery seems beneficial for clinical outcomes and contributes to organizational efficiency. A low complication risk can be obtained by trained high-volume endocrine surgeons, yet the risk is not negligible.

Feasibility of Autofluorescence for Parathyroid Glands During Thyroid Surgery and the Risk of Hypocalcemia: First Results in Belgium and Review of the Literature

Background. Post-operative hypocalcemia remains the most frequent complication after total thyroidectomy. Recently, autofluorescence imaging was introduced to detect parathyroid glands early during dissection. Aim. We aimed to check the feasibility of autofluorescence regarding the number of parathyroid glands visualised and the risk of post-operative hypocalcemia. Methods. In a prospectively gathered cohort of patients undergoing thyroid surgery, we describe the risk of hypocalcemia in relation to the number of parathyroid glands visualised during surgery (and the risk reported in the scientific literature) and the feasibility to obtain an autofluorescence of the parathyroid glands. Results. From 2010 to 2019, 1083 patients were referred for total thyroidectomy in our tertiary referral centre for endocrine surgery, of which, 40 consecutive cases were operated using autofluorescence. Among the autofluorescence group, 14 (35.0%) had all 4 parathyroid glands visualised, compared to 147 (14.1%) in the other patients, without differences in the number of parathyroid glands reimplanted. No permanent hypocalcemia occurred in the autofluorescence group and 17.5% temporary hypoparathyroidism, compared to 3.1% and 31.9% among the other patients, and 4% (95% confidence interval [CI] 3-5%) and 19% (95% CI 15-24%) in the literature. Conclusion. Autofluorescence imaging provides reliable real-time visualisation at any point during thyroid surgery and helps to identify the parathyroid glands before detection with the naked eye. To date, it cannot be used as a standard technique and does not replace meticulous dissection. To become a useful adjunct in peroperative parathyroid management, large multicentre studies need to establish a potential clinical benefit of this novel technique.

A Cohort Study Assessing the Association Between Body Composition Parameters and Symptomatic Hypocalcemia After Total Thyroidectomy

BACKGROUND

Postoperative hypocalcemia is one of the major concerns following thyroidectomy and the most frequent cause of prolonged hospital stay. The aim of this study was to evaluate the relationship between body composition parameters and symptomatic hypocalcemia following total thyroidectomy. In addition, the effects of disease- and patient-related factors on hypocalcemia were investigated.

METHODS

A total of 144 patients were prospectively included between March 2014 and September 2017. Patients were divided into 2 groups according to the presence or absence of clinical symptoms of hypocalcemia. Subsequently, the relationship between body composition parameters and hypocalcemia was evaluated.

RESULTS

Postoperative hypocalcemia-related symptoms occurred in 28 patients (19.4%). Permanent hypocalcemia was not encountered in any patient. Patients with hypocalcemic symptoms were more likely to have nodules ≥40 mm (39.3% vs. 17.2%, P = .011), retrosternal goiters (25.0% vs. 7.8%, P = .017), central lymph node dissection (LND) (32.1% vs. 11.2%, P = .015), and parathyroid autotransplantation (28.6% vs. 3.4%, P < .001) than those without symptoms. However, no differences were observed in the body composition parameters between symptomatic and asymptomatic patients. On multivariate analysis, lower preoperative intact parathyroid hormone (iPTH) levels (odds ratios (ORs) .96, 95% confidence intervals (CIs) .93-.99), the presence of retrosternal goiters (OR 10.26, 95% CI 2.23-47.14), central LND (OR 16.05, 95% CI 3.90-66.07), and parathyroid autotransplantation (OR 36.22, 95% CI 6.76-194.13) predicted hypocalcemia.

DISCUSSION

This study demonstrates that patients with lower preoperative iPTH levels, retrosternal goiters, central LND, and parathyroid autotransplantation are at an increased risk of developing clinical symptoms of hypocalcemia. Body composition parameters have no effect on the incidence of hypocalcemia after total thyroidectomy.

Outcomes After Urgent Thyroidectomy Following Rapid Control of Thyrotoxicosis in Graves' Disease are Similar to Those After Elective Surgery in Well-Controlled Disease

BACKGROUND

Surgery for Graves' disease (GD) is usually performed after adequate control with medical treatment. Occasionally, rapid pre-operative optimization is required. The primary objective was to compare the outcomes of patients undergoing elective surgery for well-controlled GD with those undergoing rapid pre-operative treatment. We also propose a formal treatment protocol for future use.

METHODS

A retrospective cohort study in a tertiary referral centre included 247 patients with well-controlled GD undergoing elective surgery and 19 patients with poorly controlled disease undergoing surgery after rapid optimization. The latter group did not respond well to thionamides (carbimazole and/or propylthiouracil) or had intolerance or side effects to thionamides and were treated with a range of non-thionamide drugs, including Lugol's iodine, cholestyramine, beta blockers and steroids (with or without thionamides), and closely monitored for 1-2 weeks before surgery. Outcome measures included thyroid storm, hypoparathyroidism and recurrent laryngeal nerve palsy.

RESULTS

In total, 266 patients with male-to-female ratio of 1:6 and median (interquartile range) age of 39 (31-51) were included. Overall, long-term recurrent laryngeal palsy and hypoparathyroidism occurred in 1 (0.38%) and 13 (4.9%) patients, respectively. No patient had thyroid storm. There was no significant difference in hypoparathyroidism (p = 1), vocal cord palsy (p = 0.803) and post-operative bleeding (p = 0.362), between elective surgery and rapid optimization groups.

CONCLUSION

Rapid pre-operative treatment is effective, safe and is associated with similar outcomes compared to usual treatment. A rapid pre-operative optimization protocol is proposed.

Systematic review of incidence, risk factors, prevention and treatment of post-laryngectomy hypoparathyroidism

Purpose

Post-laryngectomy hypoparathyroidism is associated with significant short- and long-term morbidities. This systematic review aimed to determine incidence, risk factors, prevention and treatment of post-laryngectomy hypoparathyroidism.

Methods

Medline, EMBASE and the Cochrane library were searched for relevant articles on hypocalcaemia and/or hypoparathyroidism after laryngectomy or pharyngectomy. Two authors independently screened titles and abstracts from the search. Data from individual studies were collated and presented (without meta-analysis). Quality assessment of included studies was undertaken. The review protocol was registered in the PROSPERO database (CRD42019133879).

Results

Twenty-three observational studies were included. The rates of transient and long-term hypoparathyroidism following laryngectomy with concomitant hemi- or total thyroidectomy ranged from 5.6 to 57.1% (n = 13 studies) and 0 to 12.8% (n = 5 studies), respectively. Higher transient (62.1–100%) and long-term (12.5–91.6%) rates were reported in patients who had concomitant oesophagectomy and total thyroidectomy (n = 4 studies). Other risk factors included bilateral selective lateral neck dissection, salvage laryngectomy and total pharyngectomy. There is a lack of data on prevention and management.

Conclusion

Hypoparathyroidism occurs in a significant number of patients after laryngectomy. Patients who underwent laryngectomy with concomitant hemithyroidectomy may still develop hypoparathyroidism. Research on prevention and treatment is lacking and needs to be encouraged.

The incidence of post-thyroidectomy hypocalcaemia: a retrospective single-centre audit

INTRODUCTION

The aim of this single centre retrospective observational record-based audit was to assess the incidence of post-thyroidectomy hypocalcaemia. The setting was a district general hospital in Hertfordshire covering a population of 500,000 people. A total of 196 patients who had had total or completion thyroidectomy during a five-year period were included in the study.

MATERIALS AND METHODS

The primary outcome measure was to determine the rate of biochemical and symptomatic hypocalcaemia in patients undergoing total or completion thyroidectomy. Secondary outcome measures assessed time taken for biochemical and clinical hypocalcaemia to resolve, whether malignancy affected the rate of hypocalcaemia and if removal of parathyroid glands during surgery were a predictor of hypocalcaemia.

RESULTS

The overall incidence of post-thyroidectomy hypocalcaemia (PTHC) within 24 hours was 21.4%. The incidence increased from 6 hours (13.8%) to 24 hours post-thyroidectomy (15.8%) and there was evidence of both transient and delayed PTHC within the first 24 hours. By 6 months post-surgery, 3.6% remained hypocalcaemic and required continual oral supplementation. Patients with benign thyroid disease had a higher risk of PTHC (P = 0.04) and patients younger than 50 years of age had a higher risk of symptomatic hypocalcaemia (P = 0.016). Other clinical factors including sex, type of surgery, neck dissection, oral calcium and/or vitamin D supplementation and inadvertent histological parathyroid gland excision were not associated with an increased incidence of PTHC or symptomatic hypocalcaemia.

CONCLUSIONS

Our audit shows that the rate of PTHC within our population was below the national average with higher risk in benign thyroid disease.

Early corrected serum calcium value can predict definitive calcium serum level after total thyroidectomy in asymptomatic patients

INTRODUCTION

Hypocalcemia is the most common complication of thyroidectomy, requiring supplementation as well as prolonged hospitalization. Our study's objective was to determine a corrected calcium (CCa) level on day 1 after thyroidectomy predictive of no calcium and vitamin supplementation.

MATERIALS AND METHODS

A single-center prospective study conducted between January 2012 and July 2015 in 396 patients, consisting of 331 cases of total thyroidectomy, with seven completion surgeries. The data collected were age, sex, type of thyroid surgery, etiology, anatomical pathological analysis, and the need for calcium and vitamin supplementation therapy as well as its duration. CCa levels were analyzed 20 and 30 h after surgery then on days 2 and 3. To determine a cut-off value for CCa, a ROC curve analysis was performed. The population was described in terms of numbers and associated percentages for categorical variables, and mean.

RESULTS

Mean CCa on 20 h after surgery was 2.09 mmol/L (p < 0.001) and 30 h was 2.06 mmol/L p = 0.02. CCa of less than 2.13 mmol/L was predictive of calcium and vitamin supplementation with 56% sensitivity and 97% specificity. On the evening of day 1, the cut-off value for CCa was 2.06 mmol/L with 67% sensitivity and 65% specificity.

CONCLUSION

This prospective study confirms that CCa on the first morning after surgery is reliable when it is more than 2.13 mmol/L. In total, analyzing CCa on day 1 after total thyroidectomy allows the discharge of 70% of patients on the first day after surgery, with no risk of hypocalcemia.