A prospective evaluation of quick intraoperative parathyroid hormone assay at the time of skin closure in predicting clinically relevant hypocalcemia after thyroidectomy

Early intact PTH (iPTH) is an early predictor of postoperative hypocalcemia for a safer and earlier hospital discharge: an analysis on 260 total thyroidectomies

BACKGROUND

Hypocalcemia is the most frequent complication after thyroidectomy. Serum calcium levels are reliable only 48-72 hours postoperatively. Early intact PTH (iPTH) has been proposed as early predictor of postoperative hypocalcemia. Our aim is to assess the ability of iPTH in predicting postoperative hypocalcemia.

METHODS

Two hundred and sixty patients underwent thyroidectomy with postoperative iPTH evaluation. The iPTH samplings were early performed after thyroidectomy. The calcium levels were dosed postoperatively. Age, sex, clinical diagnosis, obesity, comorbidities, previous neck surgery, preoperative therapy, type of surgery, dissectors used, lymphadenectomy, post-operative complications, reoperation and histological diagnosis were considered. The primary end-point was the postoperative hospital stay. The secondary end-points were serum calcium and iPTH. Three iPTH cut-offs were tested to assess which was the best value (10.0, 15.0, and 20.0 pg/mL).

RESULTS

The iPTH cut-off value of 10.0 pg/mL was the most accurate and specific for hypocalcemia. Comparing the iPTH value with the different values of calcium respectively 24 and 48 hours after surgery, a statistically stronger association with the serum calcium levels 48 hours postoperatively has been shown. iPTH ≥10 pg/mL 3-6 hours after surgery was strongly correlated to early discharge.

CONCLUSIONS

The correlation of iPTH with hypocalcemia is significant since a few hours after surgery and the value of iPTH ≥10 pg/mL is able to select those patients for a safe and early discharge. The use of the iPTH might avoid unnecessary extensions of hospitalization.

Hypocalcemia after thyroidectomy in patients with a history of bariatric surgery

BACKGROUND

Hypocalcemia is a common complication after total thyroidectomy. Previous bariatric surgery could be a higher factor risk for hypocalcemia due to alterations in calcium absorption and vitamin D deficiency.

OBJECTIVES

To evaluate incidence and factors involved in the risk of hypocalcemia (transient and permanent) and the postoperative outcomes of these patients after total thyroidectomy.

SETTING

University hospital in Paris, France.

METHODS

All patients who had previously undergone obesity surgery (i.e., Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric band) who had a total thyroidectomy from 2006 to 2015 were included. No patient was lost to follow-up. Each patient was matched 1:1 with a patient who had no previous bariatric surgery for age, gender, body mass index, and year of surgery.

RESULTS

Forty-eight patients were identified (43 female; mean age 48.9±9.2 yr). Nineteen patients (40%) had a postoperative hypocalcemia: transient in 14 patients (29.2%) and permanent in 5 patients (10.4%). No significant predictive clinical or biochemical factors were found for hypocalcemia risk, except for the type of bariatric procedure: Bypass surgery had a 2-fold increased risk of hypocalcemia compared to others procedures (60% versus 30%, P = .05). In the matched pair analysis, the risk of hypocalcemia was significantly higher in patients with previous bariatric surgery than in the matched cohort (40% versus 15%, P = .006).

CONCLUSION

Patients with previous bariatric surgery have an increased risk for hypocalcemia after total thyroidectomy, especially after Roux-en-Y gastric bypass. Careful and prolonged follow-up of calcium, vitamin D, and parathyroid hormone levels should be suggested for these patients.

Predictors and risk factors of hypoparathyroidism after total thyroidectomy

BACKGROUND

The aim of this study was to evaluate the risk factors for hypoparathyroidism after total thyroidectomy and to determine whether early postoperative serum levels of calcium and phosphorus could be used to predict its development.

MATERIALS AND METHODS

The study group consisted of 1030 patients who had undergone total thyroidectomy at our institution between March 2008 and July 2014. The clinicopathologic characteristics, indications for the operation, and surgical details of normocalcemic and hypocalcemic patients were compared, and variations in serum calcium and phosphorus levels were measured every day after the operation.

RESULTS

Of the 1030 patients, 291 (28.2%) were found to have transient hypocalcemia and 27 (2.6%) had permanent hypocalcemia. On univariate analysis, younger age (P = 0.001), female gender (P < 0.001), longer operative time (P = 0.009), extent of central neck dissection (CND) (P = 0.003), and malignancy (P = 0.005) were found to be significantly associated with transient hypocalcemia. On multivariate analysis, female gender (P = 0.001), extent of CND (P = 0.017), and the identification of parathyroid gland (PTG) tissue in permanent pathologic sections were significant factors. In addition, the occurrence of postoperative hypocalcemia was correlated with relative changes in serum calcium and phosphorus levels. Patients whose serum calcium levels decreased over 20% on postoperative day 2 were more likely to develop hypoparathyroidism, with 92% specificity.

CONCLUSION

Female gender (P = 0.001), extent of CND (P = 0.014), and PTG in permanent pathologic sections (P = 0.035) were found to be significant factors affecting the development of hypocalcemia. Despite some study limitations, we suggest that the relative changes in the serum levels of calcium (20%) and of phosphorus (40%) on the second postoperative day may be reliable predictors of post-thyroidectomy hypoparathyroidism.

Postoperative Hypoparathyroidism and the Viability of the Parathyroid Glands During Thyroidectomy

OBJECTIVES

To prevent hypoparathyroidism after thyroidectomy, preservation of the parathyroid glands and their vascularity are essential. The aim of this study was to determine the association between postoperative parathyroid function and the viability of the parathyroid glands during thyroidectomy.

METHODS

We prospectively analyzed 111 patients who underwent total thyroidectomy and in whom all 4 parathyroid glands were preserved in situ during the operation. The surgeons scored the viability of each parathyroid gland from 0 (normal) to 3 (severely compromised viability) based on its gross appearance and vascularity intraoperatively. The index of parathyroid viability score (IPVS) was defined as the sum of the viability scores of the 4 parathyroid glands. We evaluated the relationship between postoperative parathyroid function and IPVS.

RESULTS

Transient hypoparathyroidism occurred in 25 patients (22.5%), and permanent hypoparathyroidism in 4 patients (3.6%). The IPVS were significantly different in the three groups: 2.87±1.46 in the normal group, 3.68±1.41 in the transient hypoparathyroidism group and 7.50±1.00 in the permanent hypoparathyroidism group. The rates of transient hypoparathyroidism were 13.6% in patients with IPVS 0-2, 23.8% in patients with IPVS 3-4, and 42.9% in patients with IPVS 5-6. All the patients with IPVS of 7 or more had permanent hypoparathyroidism.

CONCLUSION

IPVS is correlated with the incidence of hypoparathyroidism. It could be a good quantitative indicator of the probability of hypoparathyroidism after thyroidectomy.

Risk of Complications after Thyroidectomy and Parathyroidectomy: A Case Series with Planned Chart Review

OBJECTIVE

To develop a predictive model for the risk of complications after thyroid and parathyroid surgery.

STUDY DESIGN

Case series with planned chart review of patients undergoing surgery, 2007-2013.

SETTING

Kaiser Permanente Northern California and Kaiser Permanente Southern California.

SUBJECTS AND METHODS

Patients (N = 16,458) undergoing thyroid and parathyroid procedures were randomly assigned to model development and validation groups. We used univariate analysis to assess relationships between each of 28 predictor variables and 30-day complication rates. We subsequently entered all variables into a recursive partitioning decision tree analysis, with P < .05 as the basis for branching.

RESULTS

Among patients undergoing thyroidectomies, the most important predictor variable was thyroid cancer. For patients with thyroid cancer, additional risk predictors included coronary artery disease and central neck dissection. For patients without thyroid cancer, additional predictors included coronary artery disease, dyspnea, complete thyroidectomy, and lobe size. Among patients undergoing parathyroidectomies, the most important predictor variable was coronary artery disease, followed by cerebrovascular disease and chronic kidney disease. The model performed similarly in the validation groups.

CONCLUSION

For patients undergoing thyroid surgery, 7 of 28 predictor variables accounted for statistically significant differences in the risk of 30-day complications; for patients undergoing parathyroid surgery, 3 variables accounted for significant differences in risk. This study forms the foundation of a parsimonious model to predict the risk of complications among patients undergoing thyroid and parathyroid surgery.

Factors affecting postoperative hypocalcemia after thyroid surgery: Importance of incidental parathyroidectomy

OBJECTIVE

The present study evaluated effects of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism on occurrence of postoperative persistent or transient hypocalcemia.

METHODS

Patients who underwent thyroidectomy at İstanbul Medeniyet University between 2013 and 2015 were included in the study. Patient information, postoperative serum calcium levels, and pathology reports were investigated retrospectively. Group 1 was made up of patients who were found to have hypocalcemia (calcium ≤8.5 mg/dL) according to postoperative serum level and normocalcemic patients were placed in Group 2. Groups were compared statistically in terms of rate of incidental parathyroidectomy, surgical technique, and presence of thyroiditis or hyperthyroidism.

RESULTS

Mean age was 49.8±12.8 years (range: 20-88). A total of 417 patients were included in the study, 74 (17.7%) were male and 343 (82.3%) were female. Group 1 consisted of 205 (49.2%) patients who had hypocalcemia according to postoperative serum level, and remaining 212 (50.8%) patients were placed in Group 2. In Group 1, 38 (18.5%) patients had incidental parathyroidectomy, and with only 18 (8.5%) patients in Group 2, a statistically significant relationship was found between incidental parathyroidectomy and hypocalcemia (p=0.003). There was no statistically significant difference in terms of presence of thyroiditis or hyperthyroidism between groups. There was statistically significant decrease in postoperative hypocalcemia rate in patients with lobectomy compared to patients with bilateral total thyroidectomy or central neck dissection (p<0.01).

CONCLUSION

Risk of postoperative hypocalcemia may be reduced with lobectomy for selected patients. In addition, delicate dissection during thyroidectomy is important in order to protect parathyroid glands and prevent hypocalcemia.

Parathyroid gland angiography with indocyanine green fluorescence to predict parathyroid function after thyroid surgery

BACKGROUND

Postoperative hypoparathyroidism remains the most common complication following thyroidectomy. The aim of this pilot study was to evaluate the use of intraoperative parathyroid gland angiography in predicting normal parathyroid gland function after thyroid surgery.

METHODS

Angiography with the fluorescent dye indocyanine green (ICG) was performed in patients undergoing total thyroidectomy, to visualize vascularization of identified parathyroid glands.

RESULTS

Some 36 patients underwent ICG angiography during thyroidectomy. All patients received standard calcium and vitamin D supplementation. At least one well vascularized parathyroid gland was demonstrated by ICG angiography in 30 patients. All 30 patients had parathyroid hormone (PTH) levels in the normal range on postoperative day (POD) 1 and 10, and only one patient exhibited asymptomatic hypocalcaemia on POD 1. Mean(s.d.) PTH and calcium levels in these patients were 3·3(1·4) pmol/l and 2·27(0·10) mmol/l respectively on POD 1, and 4·0(1.6) pmol/l and 2·32(0·08) mmol/l on POD 10. Two of the six patients in whom no well vascularized parathyroid gland could be demonstrated developed transient hypoparathyroidism. None of the 36 patients presented symptomatic hypocalcaemia, and none received treatment for hypoparathyroidism.

CONCLUSION

PTH levels on POD 1 were normal in all patients who had at least one well vascularized parathyroid gland demonstrated during surgery by ICG angiography, and none required treatment for hypoparathyroidism.

Visualizing fewer parathyroid glands may be associated with lower hypoparathyroidism following total thyroidectomy

BACKGROUND

It remains uncertain whether the number of parathyroid glands (PGs) seen during extra-capsular dissection impacts short- and long-term hypoparathyroidism. Our study aimed to address this by analyzing patients who underwent total thyroidectomy for benign disease.

METHODS

Consecutive patients undergoing total thyroidectomy were analyzed. The extra-capsular dissection technique was performed throughout the study period. The number of PGs identified, auto-transplanted and found on excised specimen was recorded prospectively. The number of PGs in situ was equaled to four minus the number of PGs auto-transplanted and PGs found on specimen. Temporary hypoparathyroidism was defined as serum adjusted calcium <2.00 mol/L 24 h after surgery and/or need for oral supplements while protracted hypoparathyroidism meant subnormal PTH (<1.2 pmol/L) at 4-6 weeks and/or need for >6-week oral supplements. Permanent hypoparathyroidism was defined as need for oral supplements for ≥1 year.

RESULTS

Five-hundred and sixty-nine patients were eligible for analysis. After adjusting for other significant parameters, greater number of PGs identified was an independent risk factor for temporary (p < 0.001) and protracted hypoparathyroidism (p = 0.007). Mean recovery time from protracted hypoparathyroidism for identifying ≤three PGs was significantly shorter than identifying all four PGs (2.8 vs. 7.8 months, p < 0.001). Chance of having all four PGs in situ decreased with greater number of PGs identified (p < 0.001).

CONCLUSIONS

When the extra-capsular technique was adopted during total thyroidectomy, identifying fewer PGs in their orthotopic positions not only lowered risk of temporary and protracted hypoparathyroidism but also shortened recovery from protracted hypoparathyroidism.

Single measurement of intact parathyroid hormone after thyroidectomy can predict transient and permanent hypoparathyroidism: a prospective study

OBJECTIVE

Immediate postoperative hypocalcemia is the most common complication of bilateral thyroidectomy. Although hypocalcemia is usually transient, it can be fatal. This study aimed to find a predictor of immediate postoperative hypocalcemia by using intact parathyroid hormone (PTH) level at 4 hours after thyroidectomy (iPTH4hr) compared with the decline in the percentage of intact PTH (%iPTH). We also followed the subjects for evaluation of permanent hypoparathyroidism.

METHODS

This was a prospective study of 65 patients (86.2% female, mean age: 43±15 years) who planned to undergo total or subtotal thyroidectomy. Preoperative and iPTH4hr were measured.

RESULTS

Thirty-nine patients (60%) were diagnosed with papillary thyroid carcinoma, while the rest were multinodular goiter (21.5%) and Graves' disease (7.7%). Significant immediate hypocalcemia was observed in 25 (38.5%) patients. Both iPTH4hr <12.5 pg/mL and %iPTH decline >72% could accurately predict significant immediate hypocalcemia. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for iPTH4hr were 92%, 87.5%, 82.1%, and 94.6%, respectively. The %iPTH decline was equal in accuracy, with sensitivity, specificity, PPV, and NPV of 84%, 90%, 84%, and 90%, respectively. At 6 months after surgery, 19 patients (29.2%) displayed permanent hypoparathyroidism. The iPTH4hr <12.5 pg/mL and %iPTH decline >72% could also predict permanent hypoparathyroidism, with sensitivity, specificity, PPV, and NPV of 100%, 80.4%, 67.9%, and 100%, and 94.7%, 84.8%, 72%, and 97.5%, respectively.

CONCLUSIONS

Only a single measurement of iPTH4hr could be helpful in identifying patients at risk of significant immediate hypocalcemia in need prompt treatment, and subsequently facilitating early discharge of patients. Also, this parameter can precisely predict permanent hypoparathyroidism.

Parathyroid autotransplantation during total thyroidectomy. Results of a retrospective study

Authors analyze their experience of parathyroid autotransplantation during total thyroidectomy, with the purpose of seeing whether this practice influenced the rate of postoperative hypocalcemia and/or hypoparathyroidism. We identified three groups of patients: group A, consisting of 57 patients, underwent parathyroid autotransplantation during total thyroidectomy; group B consisting of 87 patients not submitted to intraoperative autotransplantation in whom, as an incidental finding, a parathyroid gland was detected in the surgical specimen; group C consisted of 100 patients who did not undergo autotransplantation and whose surgical specimens were not found to contain parathyroid glands. The three groups were compared for sex and age as well as for a series of clinical and laboratory parameters on the first three postoperative days and at six months after surgery. The rate of permanent hypoparathyroidism was 3.5% in Group A, 3.45% in Group B, and 1% in Group C. Multivariate analysis revealed that all three groups showed postoperative recovery of calcium levels, although the rate and extent of this recovery differed between them. The control group showed a more rapid and more complete recovery of serum calcium values compared with Groups A and B. Calcium recovery in Groups A and B was comparable, in terms of both rate and extent. The same pattern of results emerged for the iPTH values. The analysis of the data showed that there were no significant differences in the analyzed parameters between Groups A and B. This suggests that parathyroid autotransplantation does not influence the rate of postoperative hypocalcemia and/or hypoparathyroidism.

Selectively predictive calcium supplementation using NCCN risk stratification system after thyroidectomy with differentiated thyroid cancer

BACKGROUND

Hypocalcemia is a common complication following thyroidectomy. To explore reasonable and simple methods for predicting postoperative hypocalcemia and identify the optimal strategies for selective calcium supplement are meaningful for surgeon.

METHODS

Based on the NCCN risk stratification system, patients were divided into 4 groups (A-D): low-risk group A, who only underwent limited thyroidectomy (LT) and high-risk groups B, C and D, who had received total thyroidectomy (TT) and selective central and/or lateral neck dissection (SND). After surgery, group C patients were orally given calcium gluconate and group D patients were intravenously given calcium 2 g/day for 7 days, while group B patients did not receive any calcium supplement. Serum calcium and parathyroid hormone (PTH) levels were collected before and after surgery. The incidence of asymptomatic and symptomatic hypocalcemia in each group was recorded.

RESULTS

A total of 132 patients with differentiated thyroid carcinoma (DTC) were included who received surgical treatment. No a significant change was observed in serum calcium and PTH levels in group A, while significant decreases in serum calcium and PTH levels were seen in group B (P < 0.05). Intravenous calcium supplement in group D resulted in a more rapid recovery in serum calcium levels (P < 0.05). The incidences of symptomatic hypocalcemia and asymptomatic hypocalcemia were significantly lower in group A and group D respectively compared to the other groups (All P values < 0.05). In group B, a highest asymptomatic and symptomatic hypocalcemia incidence was detected.

CONCLUSION

Selective calcium supplementation for DTC based on NCCN risk stratification system could be recommended for the high-risk patients.

Comparison of Intraoperative versus Postoperative Parathyroid Hormone Levels to Predict Hypocalcemia Earlier after Total Thyroidectomy

OBJECTIVE

To determine differences in the mean parathyroid hormone (PTH) levels for normocalcemic and hypocalcemic total thyroidectomy patients who were tested for PTH during the intraoperative or early postoperative period.

DATA SOURCES

MEDLINE, the Cochrane Database, and other databases from 1960 to 2014 in the English language and specific to humans for relevant articles.

REVIEW METHODS

Studies were included if PTH was obtained within 24 hours of thyroidectomy. Studies were excluded (1) if only a hemithyroidectomy was performed, (2) if means of studied PTH values were not reported in the article, or (3) if the time of the PTH draw fell outside of defined "intraoperative" or "early postoperative" windows. PTH values were divided into 3 groups: preoperative (control group), intraoperative (ie, discharge decisions were based on PTH values drawn in the operating room), and early postoperative (ie, PTH values at 1 to 4 hours after surgery were used as a guide).

RESULTS

The reported means of perioperative PTH levels and percentage of patients who developed hypocalcemia were collected from 14 studies. PTH evaluated at both the intraoperative and early postoperative periods was significantly lower in patients who became hypocalcemic versus patients who remained normocalcemic. There was no significant difference when PTH was measured intraoperatively or early postoperatively.

CONCLUSION

Intraoperative PTH has no significant disadvantage versus early postoperative PTH when used as a clinical guide for discharge after thyroidectomy.

Defining the syndromes of parathyroid failure after total thyroidectomy

Acute and chronic parathyroid insufficiency syndromes are the most common complication after total thyroidectomy. Permanent hypoparathyroidism imposes an important medical burden on patient lifestyle due to the need for lifetime medication, regular visits and significant long-term costs. Its true prevalence has been underestimated due to lack of clear definitions, inadequate follow-up and conflicts of interest when reporting individual patient series. The aim of this review is to propose precise definitions for the different syndromes associated to parathyroid failure based on the follow-up and management of patients developing hypocalcemia (<8 mg/dL at 24 hours) after first-time total thyroidectomy for cancer or goiter at our unit. Short and long-term post-thyroidectomy parathyroid failure presents as three different metabolic syndromes: (I) postoperative hypocalcemia is defined as a s-Ca <8 mg/dL (<2 mmol/L) within 24 hours after surgery requiring calcium/vit D replacement therapy at the time of hospital discharge; (II) protracted hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement at 4-6 weeks; and (III) permanent hypoparathyroidism as a subnormal iPTH concentration (<13 pg/mL) and/or need for calcium/vit D replacement 1 year after total thyroidectomy. Each of these syndromes has its own pattern of recovery and should be approached with different therapeutic strategies.

Early predictors of hypocalcemia after total thyroidectomy: an analysis of 304 patients using a short-stay monitoring protocol

IMPORTANCE

Postoperative hypocalcemia is common after total thyroidectomy, and perioperative monitoring of serum calcium levels is arguably the primary reason for overnight hospitalization. Confidently predicting which patients will not develop significant hypocalcemia may allow for a safe earlier discharge.

OBJECTIVE

To examine associations of patient characteristics with hypocalcemia, duration of hospitalization, and postoperative intact parathyroid hormone (IPTH) level after total thyroidectomy.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective study of consecutive patients who underwent total thyroidectomy by a single high-volume surgeon between February 1, 2010, and November 30, 2012. Postoperative serum 25-hydroxyvitamin D (vitamin D), calcium, and IPTH levels were tested within 6 to 8 hours after surgery. Mild hypocalcemia was defined as any postoperative serum calcium level of less than 8.4 to 8.0 mg/dL. Significant hypocalcemia was defined as any postoperative serum calcium level of less than 8.0 mg/dL or the development of hypocalcemia-related symptoms.

INTERVENTIONS

Total thyroidectomy.

MAIN OUTCOMES AND MEASURES

Associations of patient demographic and clinical characteristics and laboratory values with postoperative mild and significant hypocalcemia were examined using univariate analysis, and independent predictors of hypocalcemia, duration of hospitalization, and IPTH level were determined using multivariate analysis.

RESULTS

Overall, 304 total thyroidectomies were performed. Mild and significant hypocalcemia occurred in 68 (22.4%) and 91 (29.9%) patients, respectively, of which the majority were female (P = .003). The development of significant hypocalcemia was associated with postoperative IPTH level (P < .001). On multivariate analysis, males had a decreased risk of developing mild (odds ratio, 0.37 [95% CI, 0.16-0.85]) and significant (odds ratio, 0.57 [95% CI, 0.09-0.78]) hypocalcemia. Every 10-pg/mL increase in postoperative IPTH level predicted a 43% decreased risk of significant hypocalcemia (P < .001) and an 18% decreased risk of hospitalization beyond 24 hours (P = .03). Presence of malignant neoplasm carried a 27% risk of mild hypocalcemia (P = .02). There was a progressively increasing risk of lower IPTH levels for each parathyroid gland inadvertently resected or autotransplanted. Male sex and African American race were independently predictive of higher IPTH levels.

CONCLUSIONS AND RELEVANCE

Low postoperative IPTH level, female sex, and presence of malignant neoplasm are all significant, independent predictors of hypocalcemia after total thyroidectomy. Clinicians should consider these variables when deciding how to best manage or prevent postoperative hypocalcemia.

Importance of in situ preservation of parathyroid glands during total thyroidectomy

Background

Parathyroid failure is the most common complication after total thyroidectomy but factors involved are not completely understood. Accidental parathyroidectomy and parathyroid autotransplantation resulting in fewer than four parathyroid glands remaining in situ, and intensity of medical treatment of postoperative hypocalcaemia may have relevant roles. The aim of this study was to determine the relationship between the number of parathyroid glands remaining in situ and parathyroid failure after total thyroidectomy.

Methods

Consecutive patients undergoing first-time total thyroidectomy were studied prospectively, recording the number of Parathyroid Glands Remaining In Situ (PGRIS = 4 − (glands autografted + glands in the specimen)) and the occurrence of postoperative hypocalcaemia, and protracted and permanent hypoparathyroidism. Demographic, disease-related, laboratory and surgical variables were recorded. Patients were classified according to the PGRIS number into group 1–2 (one or two PGRIS), group 3 (three PGRIS) and group 4 (all four glands remaining in situ), and were followed for at least 1 year.

Results

A total of 657 patients were included, 43 in PGRIS group 1–2, 186 in group 3 and 428 in group 4. The prevalence of hypocalcaemia, and of protracted and permanent hypoparathyroidism was inversely related to the PGRIS score (group 1–2: 74, 44 and 16 per cent respectively; group 3: 51·1, 24·7 and 6·5 per cent; group 4: 35·3, 13·1 and 2·6 per cent; P &lt; 0·001). Intact parathyroid hormone concentrations at 24 h and 1 month were inversely correlated with PGRIS score (P &lt; 0·001). Logistic regression identified PGRIS score as the most powerful variable influencing acute and chronic parathyroid failure. In addition, a normal–high serum calcium concentration 1 month after thyroidectomy influenced positively the recovery rate from protracted hypoparathyroidism in all PGRIS categories.

Conclusion

In situ parathyroid preservation is critical in preventing permanent hypoparathyroidism after total thyroidectomy. Active medical treatment of postoperative hypocalcaemia has a positive synergistic effect.

Postoperative hypoparathyroidism after thyroidectomy: efficient and cost-effective diagnosis and treatment

BACKGROUND

To describe a standardized, efficient, and cost-effective protocol for the diagnosis of temporary/persisting postoperative hypoparathyroidism after (total) thyroidectomy.

METHODS

We included 237 consecutive patients who underwent (total) thyroidectomy without central neck dissection for various indications. Serum calcium (sCa) and intact parathyroid hormone (iPTH) levels were measured prospectively on the morning of postoperative day 1 to predict the long-term parathyroid metabolism. On the morning of postoperative day 2, measurements were repeated. Follow-up was performed at 1 and 6 months postoperatively.

RESULTS

On the morning of postoperative day 1, patients with iPTH ≥ 15 pg/mL (178/237; 75%) and sCa > 2.0 mmol/L were normocalcemic, and "normal" parathyroid metabolism was predicted. iPTH levels of <10 pg/mL and sCa levels of ≤2.0 mmol/L were present in 33 of the 237 patients ("disturbed" parathyroid metabolism; 14%). A "gray zone" included patients with "uncertain" parathyroid metabolism demonstrating iPTH levels between 10 and 15 pg/mL (26/237; 11%). Patients with "disturbed" and "uncertain" parathyroid metabolism were given oral calcium and vitamin D. On the morning of the second postoperative day, iPTH turned to "normal" in 10 of those 26 (38%) patients, and no further calcium or vitamin D was given. During follow-up, supplemental calcium and vitamin D was able to be stopped in all but 2 patients ("permanent" hypoparathyroidism; 2/237; 0.8%).

CONCLUSION

Measurement of iPTH on the morning after operation allows accurate prediction of postoperative parathyroid function in ≥99% of cases. This simple recommendation is practicable in all surgical units, and is an efficient and cost-effective way to recognize patients who require calcium and vitamin D supplementation.

Total thyroidectomy is associated with increased prevalence of permanent hypoparathyroidism

Background

Thyroid disorders are very common in adults. Despite advances in conservative management, surgery remains a treatment modality of choice in many cases. The mortality and morbidity of thyroidectomy are low, but long-term postoperative hypoparathyroidism (HPT) remains a prominent complication of the procedure.

The aim of this study was to assess the incidence of permanent HPT and identify the risk factors for this complication in a cohort of post-thyroidectomy patients followed at a District Endocrine Clinic.

Material/Methods

This was a retrospective analysis of 401 patients followed up at a Regional/District Endocrine Clinic, who had undergone thyroid surgery in the years 1993–2011. The percentage of patients with permanent (>12 months) HPT was the primary endpoint of the study. The statistically analyzed data of patients with permanent HPT versus the remaining patients free from postoperative complications included their demographic data, indications for surgical treatment of their thyroid disorder, and extent of the thyroid resection. The risk factors for postoperative hypoparathyroidism were assessed using logistic regression analysis.

Results

Permanent HPT following surgery on the thyroid gland occurred in 8.5% of the patients. It was more frequent following total thyroidectomy (20.2%) than near-total thyroidectomy (6.7%) or subtotal thyroidectomy (4.2%); p<0.0001. A multivariate statistical regression analysis demonstrated that primary total thyroidectomy was a significant risk factor for permanent HPT (OR 6.5; 95% CI: 2.9–14.4; p<0.0001).

Conclusions

Total thyroidectomy was associated with increased prevalence of permanent hypoparathyroidism when compared to less extensive thyroid resection modes in patients with benign thyroid diseases.

How useful are perioperative biochemical parameters in predicting the duration of calcium and/or vitamin D supplementation after total thyroidectomy?

BACKGROUND

Oral calcium and calcitriol are often prescribed after total thyroidectomy to avoid biochemical and/or symptomatic hypocalcemia. We aimed to identify independent perioperative factors that correlated with the duration of calcium and/or calcitriol supplementation after total thyroidectomy.

METHODS

Of 271 eligible patients, 48 (17.7 %) required calcium and/or calcitriol supplements on discharge. Patients were gradually weaned from the supplementation by one surgeon according to a biweekly algorithm based on serum calcium (Ca). Duration of supplementation was calculated from the date of operation to the date of ceasing all supplementation without biochemical hypocalcemia (i.e., serum adjusted Ca ≥ 8.44 mg/dL). The Cox regression analysis was performed to identify independent perioperative factors for duration of supplementation. The best cut-off value for these independent factors was determined by the receiver characteristic curve.

RESULTS

In the multivariate analysis, parathyroid hormone (PTH) at skin closure (PTH-SC) (RR 1.742, 95 % CI 1.080-2.810) and on postoperative day 1 adjusted Ca (Ca-D1) (RR 77.526, 95 % CI 3.600-1669.57) were the only two independent determinants for shorter duration before ceasing all supplementation. The best cut-off values in predicting supplementation ≥ 6 months for PTH-SC and Ca-D1 were 7.08 pg/mL (sensitivity = 100 %, specificity = 60.5 %, PPV = 40.0 % and NPV = 100 %) and 7.88 mg/dL (sensitivity = 90.0 %, specificity = 55.3 %, PPV = 34.6 % and NPV = 95.5 %), respectively.

CONCLUSIONS

Both PTH-SC and Ca-D1 were independently associated with the duration of supplementation after total thyroidectomy. Almost all patients with PTH-SC ≥ 7.08 pg/mL or Ca-D1 ≥ 7.88 mg/dL did not require supplementation ≥ 6 months whereas about one third of patients with PTH-SC <7.08 pg/mL or Ca-D1 <7.88 mg/dL required supplementation ≥ 6 months.

Incidence and predictors of post-thyroidectomy hypocalcaemia in a tertiary endocrine surgical unit

BACKGROUND

Post-thyroidectomy hypocalcaemia is a common complication with significant short and long term morbidity. The aim of this study was to determine the incidence and predictors of post-thyroidectomy hypocalcaemia (as defined by a corrected calcium <2.1 mmol/l) in a tertiary endocrine surgical unit.

METHODS

A total of 238 consecutive patients who underwent completion or bilateral thyroid surgery between 2008 and 2011 were included in this retrospective study. Clinical and biochemical data were obtained from electronic and hard copy medical records.

RESULTS

The incidence of post-thyroidectomy hypocalcaemia on first postoperative day (POD1) was 29.0%. There was variation in the incidence of hypocalcaemia depending on the timing of measurement on the first postoperative day. At six months following surgery, 5.5% of patients were on calcium and/or vitamin D supplementation. Factors associated with post-thyroidectomy hypocalcaemia were lower preoperative corrected calcium (p=0.005) and parathyroid gland (PTG) auto-transplant (p=0.001). Other clinical factors such as central lymph node dissection, inadvertent PTG excision, ethnicity, preoperative diagnosis and Lugol's iodine were not associated with post-thyroidectomy hypocalcaemia.

CONCLUSION

The incidence of post-thyroidectomy hypocalcaemia was underestimated by 6% when only POD1 measurements were considered. The timing of measurement on POD1 has an impact on the incidence of post-thyroidectomy hypocalcaemia. Auto-transplantation and lower preoperative calcium were associated with post-thyroidectomy hypocalcaemia.

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

BACKGROUND

Hypocalcaemia is common after thyroidectomy. Accurate prediction and appropriate management may help reduce morbidity and hospital stay. The aim of this study was to perform a systematic literature review and meta-analysis of predictors of post-thyroidectomy hypocalcaemia.

METHODS

A systematic search of PubMed, EMBASE and the Cochrane Library databases was undertaken, and the quality of manuscripts assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Some 115 observational studies were included. The median (i.q.r.) incidence of transient and permanent hypocalcaemia was 27 (19-38) and 1 (0-3) per cent respectively. Independent predictors of transient hypocalcaemia included levels of preoperative calcium, perioperative parathyroid hormone (PTH), preoperative 25-hydroxyvitamin D and postoperative magnesium. Clinical predictors included surgery for recurrent goitre and reoperation for bleeding. A calcium level lower than 1·88 mmol/l at 24 h after surgery, identification of fewer than two parathyroid glands (PTGs) at surgery, reoperation for bleeding, Graves' disease and heavier thyroid specimens were identified as independent predictors of permanent hypocalcaemia in multivariable analysis. Factors associated with transient hypocalcaemia in meta-analyses were inadvertent PTG excision (odds ratio (OR) 1·90, 95 per cent confidence interval 1·31 to 2·74), PTG autotransplantation (OR 2·03, 1·44 to 2·86), Graves' disease (OR 1·75, 1·34 to 2·28) and female sex (OR 2·28, 1·53 to 3·40).

CONCLUSION

Perioperative PTH, preoperative vitamin D and postoperative changes in calcium are biochemical predictors of post-thyroidectomy hypocalcaemia. Clinical predictors include female sex, Graves' disease, need for parathyroid autotransplantation and inadvertent excision of PTGs.

Resection of a giant bilateral retrovascular intrathoracic goiter causing severe upper airway obstruction, 2 years after subtotal thyroidectomy: a case report and review of the literature

The intrathoracic (or substernal) goiter is more often benign; but it can be malignant in 2-22% of patients. There is history of prior thyroid surgery in 10% to more than 30% of patients. Intrathoracic goiters cause adjacent structure compression more frequently than the cervical goiters, due to the limited space of the thoracic cage. Compression of trachea, oesophagus, vascular and neural structures may cause dyspnoea, dysphagia, superior vena cava syndrome, subclavian vein thrombosis, hoarseness, and Horner's syndrome. There is usually progressive deterioration, but acute exacerbation may occur. The presence of a thoracic goiter (>50% of the mass below the thoracic inlet) is per se an indication for resection. Tracheal compression by (cervical or thoracic) goiter is also an indication for resection; early tracheal decompression is recommended particularly in symptomatic patients. In severe respiratory distress, intubation and semi-urgent operation may be required. With early intervention, most intrathoracic goiters can be removed through a cervical approach, while tracheomalacia is avoided. We hereby present successful and uncomplicated total thyroidectomy, through a median sternotomy, of a benign, gigantic, bilateral, retrovascular, posterior mediastinal, intrathoracic goiter, encircling the trachea, and causing severe respiratory distress in a 63 year old man with history of previous subtotal thyroidectomy.

A comparison of surgical morbidity and scar appearance between gasless, transaxillary endoscopic thyroidectomy (GTET) and minimally invasive video-assisted thyroidectomy (VAT)

Background

The gasless, transaxillary endoscopic thyroidectomy (GTET) and minimally invasive video-assisted thyroidectomy (VAT) are both well-recognized endoscopic thyroid procedures, but how their postoperative outcomes are compared remains unclear. The present study was designed to compare surgical morbidities/complications and scar appearance between GTET and VAT at our institution.

Methods

Of the 141 patients eligible for endoscopic thyroidectomy, 96 (68.1 %) underwent GTET and 45 (31.9 %) underwent VAT. Patient demographics, indications, operative findings, pain scores on days 0 and 1, and surgical morbidities were compared between the two groups. At 6 months after surgery, all patients were asked about their satisfaction on the cosmetic result by giving a score (Patient Satisfaction Score or PSS) and their scar appearance was assessed by the 11 domains in the Patient and Observer Scar Assessment Scale (POSAS).

Results

GTET was associated with a significantly longer operating time (84 vs. 148 min, p = 0.005), higher pain scores on days 0 and 1 (2.9 vs. 2.3, p = 0.042 and 2.2 vs. 1.7, p = 0.033, respectively), overall recurrent laryngeal nerve (RLN) injury (6.3 vs. 0 %, p = 0.043), and overall morbidity rates (12.5 vs. 2.2 %, p = 0.049) than VAT. The actual individual score for the 11 domains in POSAS and for PSS remained similar between the two groups. They remained similar even when patients with morbidity were excluded.

Conclusions

GTET was a technically more challenging procedure and was associated with longer hospital stay, longer operating time, more immediate pain, and increased overall RLN injury and morbidity than VAT. The 6-month POSAS and PSS were similar between the two procedures.