Outcomes of Parathyroid Autotransplantation During Total Thyroidectomy: A Comparison with Age- and Sex-Matched Controls

Single inferior parathyroid autotransplantation during total thyroidectomy with bilateral central lymph node dissection for papillary thyroid carcinoma: a retrospective cohort study

BACKGROUND

Management of the inferior parathyroid gland using total thyroidectomy (TT) with central lymph node dissection (CLND) is still controversial. Therefore, we evaluated the safety and effectiveness of single inferior parathyroid autotransplantation.

METHODS

The clinical data of patients with papillary thyroid carcinoma (PTC) who underwent TT with bilateral CLND from January 2018 to December 2020 were collected. Quality of life (QoL) was assessed using the Chinese version of the EORTC QLQ-C30 and THYCA-QOL. The patients were divided into an autotransplantation group and a preservation group according to whether a single inferior parathyroid gland was transplanted. The incidence of permanent hypoparathyroidism, the number of resected central lymph nodes (CLNs), the rate of recurrence reoperation, the rate of radioactive iodine (RAI) treatment, and the QoL score were compared between the two groups.

RESULTS

A total of 296 patients were included in the study; there were 99 patients in the autotransplantation group and 197 in the preservation group. The incidence of permanent hypoparathyroidism was 3.0% (3/99) and 4.6% (9/197) in the autotransplantation and preservation groups, respectively (P = 0.532). The median number of resected CLNs was 12 (8-17) and 10 (6-14) in the autotransplantation and preservation groups, respectively (P = 0.015). No reoperations were performed for patients with CLN recurrence, and the rates of lateral lymph node (LLN) recurrence reoperation were 2.0% (2/99) and 3.6% (7/197) in the autotransplantation and preservation groups, respectively (P = 0.473). The RAI treatment rates were 12.1% (12/99) and 22.3% (44/197) in the autotransplantation and preservation groups, respectively (P = 0.034). A total of 276 questionnaires were recovered, including 84 in the autotransplantation group and 192 in the preservation group. The QoL of the two groups of patients is similar (P > 0.05).

CONCLUSION

Single inferior parathyroid autotransplantation during thyroidectomy can be used to prevent permanent hypoparathyroidism and can enable more extensive CLND.

Hypoparathyroidism: State of the Art on Cell and Tissue Therapies

Hypoparathyroidism is an endocrine disorder characterized by low serum calcium levels, high serum phosphorus levels, and by inappropriate or absent secretion of the parathyroid hormone (PTH). The most common therapeutic strategy to treat this condition is hormone replacement therapy with calcium and vitamin D but, unfortunately, in the long term this treatment may not be sufficient to compensate for the loss of endocrine function. Glandular autotransplantation is considered the most effective technique in place of replacement therapy. Although it leads to excellent results in most cases, autotransplantation is not always possible. Allograft is a good way to treat patients who have not been able to undergo autograft, but this technique has limited success due to side effects related to tissue rejection. This therapy is supported by systemic immunosuppression, which leads to the onset of serious side effects in patients, with a risk of endocrine toxicity. Today, research on endocrine disorders is focused on discovering alternative graft therapies that can allow optimal results with the fewest possible side effects. In this review, we will make an update on the current state of the art about the cell and tissue therapy as treatment for hypoparathyroidism, to identify which type of therapeutic strategy could be valid for a future clinical use.

Does number of autotransplanted parathyroid glands affects postoperative hypoparathyroidism and serum parathyroid hormone levels?

BACKGROUND

To investigate how number of autotransplanted parathyroid glands (PGs) affects the incidence of postoperative hypoparathyroidism and the recovery of parathyroid function.

METHODS

A systematic search was performed in the MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases. The evaluated indices included the incidence of postoperative transient and permanent hypoparathyroidism and parathyroid hormone (PTH) levels during follow-up.

RESULTS

Twenty articles with 7291 patients were included. A higher incidence of transient hypoparathyroidism was found in the PG autotransplantation group than in the preservation group (odds ratio [OR]: 2.37; 95% confidence interval [CI]: 1.90, 2.96). However, there was no significant difference between the two groups regarding permanent hypoparathyroidism (OR: 1.17; 95% CI: 0.71, 1.91). Parathyroid hormone (PTH) levels in the PG autotransplantation group changed significantly more than the preservation group at postoperative 1-day and 1-month, but became similar at the 6-month, 1-year and 2-year follow-up. Autotransplantation of 2 and 3 PGs demonstrated a higher incidence of transient hypoparathyroidism than 1 PG (OR: 2.09; 95% CI: 1.41, 3.11 and OR: 9.70; 95% CI: 2.11, 44.39, respectively), but no significant difference was observed between the autotransplantation of 3 and 2 PGs (OR: 0.99; 95% CI: 0.03, 29.06). Additionally, the incidence of permanent hypoparathyroidism was not significantly different when different number of PGs was autotransplanted.

CONCLUSIONS

PG autotransplantation is an effective mid- and long-term strategy for the preservation of parathyroid function. Although transient hypoparathyroidism was positively correlated with the number of autotransplanted PGs, no remarkable correlation was observed for permanent hypoparathyroidism.

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

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

Near-infrared auto-fluorescence spectroscopy combining with Fisher's linear discriminant analysis improves intraoperative real-time identification of normal parathyroid in thyroidectomy

BACKGROUND

To evaluate the efficacy of a sensitive, real-time tool for identification and protection for parathyroid glands during thyroidectomy.

METHODS

Near-infrared (NIR) auto-fluorescence was measured intraoperatively from 20 patients undergoing thyroidectomy. Spectra were measured from suspicious parathyroid glands and surrounding neck tissues during the operation with a NIR fluorescence system. Fast frozen sections were performed on the suspicious parathyroid glands. Accuracy was evaluated by comparison with histology and NIR identification. Data were attracted for Fisher's linear discriminant analysis.

RESULTS

The auto-fluorescence intensity of parathyroid was significantly higher than that of thyroid, fat and lymph node. The peak intensity of auto-fluorescence from parathyroid was 5.55 times of that from thyroid at the corresponding wave number. Of the 20 patients, the parathyroid was accurately detected and identified in 19 patients by NIR system, compared with their histologic results. One suspicious parathyroid did not exhibit typical spectra, and was proved to be fat tissue by histology. The NIR auto-fluorescence method had a 100% sensitivity of parathyroid glands identification and a high accuracy of 95%. The positive predictive value was 95%. The parathyroid gland have specific auto-fluorescence spectrum and can be separated from the other three samples through the Fisher's linear discriminant analysis.

CONCLUSIONS

NIR auto-fluorescence spectroscopy can accurately identify normal parathyroid gland during thyroidectomy. The Fisher's linear discriminant analysis demonstrated the specificity of the NIR auto-fluorescence of parathyroid tissue and its efficacy in parathyroid discrimination.

Hypoparathyroidism After Total Thyroidectomy: Importance of the Intraoperative Management of the Parathyroid Glands

BACKGROUND

Total thyroidectomy is the most common surgical procedure for the treatment of thyroid diseases. Postoperative hypocalcemia/hypoparathyroidism is the most frequent complication after total thyroidectomy. The aim of this study was to evaluate the rate of postoperative hypocalcemia and permanent hypoparathyroidism after total thyroidectomy in order to identify potential risk factors and to evaluate the impact of parathyroid autotransplantation.

PATIENTS AND METHODS

We performed a retrospective analysis of 1018 patients who underwent total thyroidectomy at our institution between 2000 and 2016. Medical records were reviewed to analyze patient features, clinical presentation, management and postoperative complications. Descriptive and inferential statistics were employed based on the natural scaling of each included variable. Statistical significance was set at p ≤ 0.05.

RESULTS

Mean ± SD age was 46.79 ± 15.9 years; 112 (11.7%) were males and 844 (88.3%) females. A total of 642 (67.2%) patients underwent surgery for malignant disease. The rate of postoperative hypocalcemia, transient, protracted and permanent hypoparathyroidism was 32.8%, 14.43%, 18.4% and 3.9%, respectively. Permanent hypoparathyroidism was significantly associated with the number of parathyroid glands remaining in situ (4 glands: 2.5%, 3 glands: 3.8%, 1-2 glands: 13.3%; p ˂ 0.0001) [OR for 1-2 glands in situ = 5.32, CI 95% 2.61-10.82]. Other risk factors related to permanent hypoparathyroidism were obesity (OR 3.56, CI 95% 1.79-7.07), concomitant level VI lymph node dissection (OR 3.04, CI 95% 1.46-6.37) and incidental parathyroidectomy without autotransplantation (OR 3.6, CI 95% 1.85-7.02).

CONCLUSIONS

Identification and in situ preservation of at least three parathyroid glands were associated with a lower rate of postoperative hypocalcemia (30.4%) and permanent postoperative hypoparathyroidism (2.79%).

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

Objective

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

Methods

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

Results

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

Conclusions

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

Intraoperative carbon nanoparticles mapping in secondary total thyroidectomy for recurrent thyroid nodules: Results of a 8-criterion case-match study (case control study)

BACKGROUND

The extent of total thyroidectomy in the management of multinodular goiter remains unclear. Compared to primary thyroidectomy, secondary total thyroidectomy is more difficult to perform and carries a significantly higher risk of postoperative complications such as recurrent laryngeal nerve (RLN) palsy or hypoparathyroidism. In this study, we aimed to evaluate the efficacy and safety of intraoperative carbon nanoparticle (CN) mapping in patients undergoing secondary total thyroidectomy.

METHODS

We performed a case-matched analysis of a prospectively maintained database using 8 specific criteria to compare perioperative outcomes after primary total thyroidectomy to those after secondary total thyroidectomy with intraoperative CN mapping. The criteria included age, sex, operative procedure, RLN/parathyroid glands (PGs) exploration, preoperative vocal cord calcium abnormalities, and pathological results. Thirty-five patients underwent secondary total thyroidectomy with intraoperative CN mapping due to recurrent thyroid nodules or development of nodules suspicious for malignancy after subtotal thyroidectomy. Fifty exact matches for all 8 criteria were identified from the database in our previous study, which included records of 3078 primary thyroidectomies without CNs. Perioperative outcomes, surgical technique, and complications were analyzed.

RESULTS

The RLNs were successfully identified in all 35 patients. Among three patients that experienced slight hoarseness, one had an RLN end-to-end anastomosis with subsequent improvement in the during the 12-month follow-up period. Two patients experienced changes in vocal tone, but recovered after several months. Two patients underwent parathyroid auto-transplantations, and subsequently presented with transient hypocalcaemia. Their symptoms gradually remitted within one year. Except for mean operation time, there were no statistically significant differences in complications between the primary total thyroidectomies and the secondary total thyroidectomy with CNs.

CONCLUSIONS

Intraoperative CN mapping, expert knowledge of the jugular anatomy, and standardized resection procedures can minimize the incidence of complications such as RLN palsy and hypoparathyroidism after secondary total thyroidectomy.

A new classification of parathyroid glands to evaluate in situ preservation or autotransplantation during thyroid surgery

The indication for autotransplantation of parathyroid glands is still controversial. A new classification of parathyroid glands based on the positional relationship among parathyroid glands, thyroid gland and thymus was created to decide in situ preservation or autotransplantation during thyroid surgery.A retrospective study included patients with papillary thyroid cancer who underwent total thyroidectomy with bilateral central lymph node dissection between November 2014 and November 2016. According to the application of the new classification (December 2015-November 2016) or traditional method (preservation of all functional parathyroid glands in situ, November 2014-November 2015), the patients were divided into new classification and traditional groups.The traditional method was utilized in 288 patients who underwent surgery during the first half of the study, while the new classification was applied to 249 patients during the latter half of the study. The incidence of transient hypoparathyroidism was 43.0% (107/249) in new classification group and 35.8% (103/288) in the traditional group, respectively (P = .093). The corresponding incidence of permanent hypoparathyroidism was 0.4% (1/249) and 4.5% (13/288) (P = .002).The new classification of parathyroid glands potentially reflects the difficulty of preservation and helps to make a reasonable decision on preservation or autotransplantation of a parathyroid gland, which may minimize the incidence of permanent hypoparathyroidism.

Parathyroid Autotransplantation During thyroid Surgery. Where we are? A Systematic Review on Indications and Results

Introduction: Hypoparathyroidism still represents an important concern in thyroid surgery. Careful dissection with identification and preservation of parathyroid glands in situ remains the best way to maintain gland vitality and avoid post-operative failure. Nevertheless, parathyroid glands are still inadvertently removed in up to 11% of cases. Parathyroid autotransplantation may represent the only way to restore parathyroid gland functionality in case of inadvertent removal or devascularization during thyroid surgery. Despite this, there is still no agreement on the effectiveness of this procedure. The present systematic review is focused on the mainly debated matters regarding the procedure, indications, technique and results. Methods: This review has been carried out according to PRISMA statement and checklist. The research item was: (((parathyroid autotransplantation[Title]) OR parathyroid reimplantation[Title]) NOT hyperparathyroidism[Title]) AND english[Language]. Results: A total of 31 studies have been found according to limitations already described, reporting from 4 to 890 procedures, with a total amount of 4088 PA. Among these studies, there are only 7 prospective case-series evaluations, 2 prospective randomized trials, while the other 22 studies are retrospective evaluations. The main concerns are: when and how to perform autotransplantation; in which anatomical site; which result to be expected, and how to manage and control the graft. Conslusions: Parathyroid autotransplantatin is an important tool to avoid or minimize the risk for hypoparathyroidism following thyroid surgery in selected cases. Parathormone assay can help the surgeon to determine when reimplantation is indicated or not. Further studies could theoretically give definitive results.

Does the number of parathyroid glands autotransplanted affect the incidence of hypoparathyroidism and recovery of parathyroid function?

BACKGROUND

The relationship between the number of parathyroid glands autotransplanted and hypoparathyroidism as well as recovery of parathyroid function is not understood fully. The aim was to ascertain whether the number of autotransplanted glands affected the incidence of hypoparathyroidism and recovery of parathyroid function in long-term follow-up after thyroidectomy.

METHODS

A retrospective cohort study included all patients with papillary thyroid carcinoma who underwent first-time total thyroidectomy with central neck dissection between June 2012 and June 2015. The patients were divided into 4 groups (0, 1, 2, and 3) on the basis of the number of parathyroid glands autotransplanted.

RESULTS

Of the 766 patients, 283 (36.9%) had no gland autotransplanted, and 373 (48.7%), 97 (12.7%), and 13 (1.7%) had 1, 2, and 3 glands autotransplanted, respectively. More lymph nodes and more metastatic ones in the central compartment were retrieved in groups 2 and 3 (P < .05). With increasing number of autotransplanted glands, the incidence of transient hypoparathyroidism was 26.1%, 36.2%, 52.6%, and 84.6% (P < .05), and the incidence of permanent hypoparathyroidism was 1.8%, 1.1%, 1.0%, and 0% (P > .05). The recovery rates of serum parathyroid hormone concentration were 84.7%, 82.2%, 82.0%, and 79.2% after 2-year follow-up (P > .05).

CONCLUSION

Autotransplantation is an effective strategy for restoration of parathyroid function. Transient hypoparathyroidism is positively correlated to the number of autotransplanted parathyroid glands during total thyroidectomy with central neck dissection. There is no increase in permanent hypoparathyroidism in patients with a higher number of autotransplanted glands, despite more extensive lymph node disease. (Surgery 2018;161:XXX-XXX.).

Effect of autotransplantation of a parathyroid gland on hypoparathyroidism after total thyroidectomy

BACKGROUND

The effect of parathyroid autotransplantation on hypoparathyroidism is not fully understood. The purpose of the study was to determine the effect of autotransplantation of a parathyroid gland on the incidence of hypoparathyroidism and recovery of parathyroid function at 6 months after total thyroidectomy with central neck dissection for papillary thyroid carcinoma.

METHODS

All patients with autotransplantation of a parathyroid gland (no inadvertent parathyroidectomy) (group A), in situ preservation of all parathyroid glands (no autotransplantation and inadvertent parathyroidectomy) (group B) or inadvertent removal of a parathyroid gland (no autotransplantation) (group C) who underwent first-time total thyroidectomy with central neck dissection for papillary thyroid carcinoma between January 2013 and June 2016 were included retrospectively.

RESULTS

Of the 702 patients, 383, 297 and 22 were respectively included in the groups A, B and C. The overall rates of transient and permanent hypoparathyroidism were 37.6% and 1.0%. The incidence of transient hypoparathyroidism was 43.9, 29.0 and 45.5% (A vs B, P = 0.000; A vs C, P = 1.000), and the incidence of permanent hypoparathyroidism was 1.0, 0.7 and 4.5% (P > 0.05). The recovery rates of serum parathyroid hormone levels were 71.4, 72.2 and 66.0% at 6-month follow-up (P > 0.05).

CONCLUSION

Autotransplantation of a parathyroid gland does not affect the incidence of permanent hypoparathyroidism, but increases the risk of transient hypoparathyroidism when the rest of parathyroid glands are preserved in situ. At least 2 parathyroid glands should be preserved during total thyroidectomy with central neck dissection to prevent permanent hypoparathyroidism.

Short and long-term impact of parathyroid autotransplantation on parathyroid function after total thyroidectomy

The most common complication of total thyroidectomy is parathyroid insufficiency. Acute, transient, post-operative hypoparathyroidism increases length of hospitalization, morbidity and cost associated with total thyroidectomy. While permanent hypoparathyroidism poses a significant medical burden with lifetime medication, regular follow up and considerable disease burden related to chronic renal failure and other sequelae. Parathyroid autotransplantation has been demonstrated to result in biochemically functional grafts, leading to the procedures' common use during total thyroidectomy. The clearest indications for parathyroid auto transplantation are inadvertently removed or devascularized parathyroid glands. Some centers utilize routine autotransplantation to reduce the risk of permanent hypoparathyroidism. Novel fluorescence techniques to aid in parathyroid detection during thyroid surgery are under evaluation. This review aims to define the role and impact of parathyroid autotransplantation undertaken during total thyroidectomy.

INCIDENTAL PARATHYROIDECTOMY DURING THYROID SURGERY - RISK, PREVENTION AND CONTROVERSIES; AN EVIDENCE-BASED REVIEW

Background

Postoperative hypocalcemia after thyroid surgery has a high prevalence ( 16-55% in different series). Incidental parathyroidectomy (IP) is a less discussed complication of thyroidectomy with consequences not properly defined. The aim of our study was to find incidence, risk factors and how to prevent IP.

Methods

Extensive search of English literature publications via PubMed was performed and 73 papers from 1980 to 2017 were analysed using the GRADE system/classification, quality of evidence was classified as "strong" when the result is highly unlikely to change existing recommendation and "weak" when opposite.

Results

Incidence of IP is 3.7-24.9%, while prevalence of permanent hypoparathyroidism is less frequent 6-12%. Direct relation between IP and hypoparathyroidism/hypocalcemia remains controversial. Female patients, ectopic parathyroids, small thyroids, Graves', malignancy, redo surgeries and total thyroidectomy favour IP. Routine visualization of parathyroids, new hemostatic devices, magnifying instruments and fluorescence can prevent incidental removal of parathyroids. Incidence of IP during videoassisted or robotic thyroidectomies was similar to open procedures. High volume, experienced and younger surgeons have lower complication rates (including hypoparathyroidism).

Conclusions

Incidental parathyroidectomy is more frequent than we might have expected. It should be avoided and parathyroid glands should be kept in situ. Majority of studies are retrospective (low degree of evidence according to previous mentioned GRADE classification) and further meta-analysis or randomized control studies are welcome in order to define the impact of incidental removal of parathyroids on postoperative outcome.