Parathyroid autotransplantation during thyroidectomy: documentation of graft function

Guideline From the Brazilian Society of Surgical Oncology and Brazilian College of Surgeons in Preventing and Managing Acute Hypoparathyroidism After Thyroid Surgery

The risk of hypoparathyroidism and hypocalcemia is a critical concern in thyroid surgery. Preserving parathyroid gland vascularization during surgery is essential for effective prevention. Preoperative and postoperative management, including calcium and Vitamin D supplementation, is paramount. Measurement of parathyroid hormone levels after surgery is the best predictor of hypoparathyroidism. This guideline offers recommendations for the prevention, diagnosis, and treatment of acute hypoparathyroidism and hypocalcemia after thyroid surgery.

5-year Follow-up of Reimplanted Parathyroid Glands in Forearm Subcutaneous Tissue During Thyroidectomy. A Confirmation of Graft Vitality in a Large Series of Patients

INTRODUCTION

The aim of this study is to assess the outcomes of parathyroid gland reimplantation with PR-FaST technique in patients undergoing thyroid surgery, focusing on graft functionality over a 5-year follow-up period.

MATERIALS AND METHODS

We analyzed data from 131 patients who underwent parathyroid reimplantation using the PR-FaST technique during thyroid surgery due to inadvertent parathyroid removal or evident vascular damage. Postoperative evaluations included serum calcium (Ca), magnesium (Mg), and phosphorus (P) analyses on the 1st and 2nd postoperative days, at 10 days, and at 1, 3, 6 months, 1 year, and 5 years of follow-up. Additionally, the mean values of serum intact parathyroid hormone (iPTH) concentration were measured from blood samples collected from both the reimplanted arm (iPTH RA) and non-reimplanted arm (iPTH NRA) within the same period.

RESULTS

Among 131 patients, at 10 days post-surgery, only 46 patients (35.1%) out of 131 exhibited graft viability (iPTH ratio >1.5). This percentage increased to 72.8% (94 patients) after 1 month and further to 87.8% (108 patients) after 3 months post-surgery. At 1 year, 84.7% of patients showed good graft functionality. After 5 years, the percentage remained stable, with graft viability observed in 81.3% of patients. Only 91 of the initial 131 patients completed follow-up up to 5 years, with a dropout rate of 30.5 %.

CONCLUSIONS

Parathyroid reimplantation using the PR-FaST technique is a viable option for patients undergoing thyroidectomy and has been shown to be a reproducible and effective technique in most patients, with sustained graft functionality and parathyroid hormone production over a 5-year follow-up period.

Investigating the optimal parathyroid autotransplantation strategy in transareolar endoscopic thyroidectomy: A retrospective cohort study

BACKGROUND

There is ongoing debate about whether intraoperative parathyroid autotransplantation effectively prevents permanent hypoparathyroidism after thyroidectomy. This study aims to examine its impact on postoperative parathyroid function and determine the best autotransplantation strategy.

METHODS

A retrospective analysis was conducted on 194 patients who underwent total thyroidectomy with central lymph node dissection (CLND) for papillary thyroid carcinoma (PTC). Patients were divided into four groups based on the number of parathyroid autotransplants during surgery: Group 1 (none, n = 43), Group 2 (1 transplant, n = 60), Group 3 (2 transplants, n = 67), and Group 4 (3 transplants, n = 24). Various clinical parameters were collected and compared among the groups.

RESULTS

Parathyroid autotransplantation was identified as a risk factor for temporary hypoparathyroidism (OR: 1.74; 95% CI: 1.27-2.39, P = 0.001) and a protective factor for permanent hypoparathyroidism (OR: 0.27; 95% CI: 0.14-0.55, P < 0.001). At 12 months postoperative, systemic parathyroid hormone (PTH) levels increased progressively from Groups 1 to 4, with significant differences observed only between Group 1 and Group 2 (P < 0.02). Difference values in systemic PTH levels between Month 1 and Day 1 postoperative increased progressively from Groups 1 to 4, with statistically significant differences observed between adjacent groups (P < 0.02). The number of dissected positive lymph nodes increased progressively across the four groups, showing statistical differences (P < 0.02).

CONCLUSION

Parathyroid autotransplantation can prevent permanent hypoparathyroidism. Additionally, we recommend preserving parathyroids in situ whenever possible. If autotransplantation is required, it should involve no more than two glands.

Diagnostic value of contrast-enhanced ultrasound in judging the survival of graft after heteroautoplasty for secondary hyperparathyroidism

BACKGROUND

Secondary hyperparathyroidism (SHPT) is one of the common complications of end-stage renal disease-uremia, and is mainly manifested as parathyroid hyperplasia and abnormal secretion of parathyroid hormone (PTH).

OBJECTIVE

To investigate the value and advantages of contrast-enhanced ultrasound (CEUS) in evaluating the survival of autografts after parathyroidectomy + parathyroid autotransplantation.

METHODS

In this study, 125 patients with renal failure due to polycystic kidney disease, chronic nephritis, diabetic nephropathy, lupus nephritis, and atherosclerotic nephropathy were enrolled as the participants and each of them had 4 secondary hyperactive parathyroid glands and underwent parathyroid autotransplantation. One parathyroid gland was taken from each patient and equally divided into 4 parts and placed in the subcutaneous fat of one forearm for transplantation. CEUS was performed 14 days after the transplantation to observe the micro blood supply of the graft and assess the survival and secretory function of the transplanted parathyroid. The grafts were divided into the partial survival group and the total survival group based on the enhancement characteristics. The survival of the grafts was determined by comparing the parathyroid hormone level in bilateral elbow cephalic veins 1 month after surgery.

RESULTS

Among the 125 patients, 112 had linear or punctate enhancement of 2-4 parathyroid glands 14 days after surgery, and 13 patients had linear or punctate enhancement of 0-1 parathyroid gland. There were statistically significant differences in the perfusion pattern, enhancement uniformity, and parathyroid hormone levels in the cephalic veins at the elbow on both the graft and non-graft sides among all groups (P< 0.05).

CONCLUSION

Compared to the detection of the difference in the parathyroid hormone level in the cephalic vein of bilateral elbows 1 month after surgery, CEUS can reflect the parathyroid survival after transplantation more quickly and accurately 2 weeks later, and provide a more rapid and agile non-invasive clinical diagnosis method.

Comparing laser speckle contrast imaging and indocyanine green angiography for assessment of parathyroid perfusion

Accurate intraoperative assessment of parathyroid blood flow is crucial to preserve function postoperatively. Indocyanine green (ICG) angiography has been successfully employed, however its conventional application has limitations. A label-free method overcomes these limitations, and laser speckle contrast imaging (LSCI) is one such method that can accurately detect and quantify differences in parathyroid perfusion. In this study, twenty-one patients undergoing thyroidectomy or parathyroidectomy were recruited to compare LSCI and ICG fluorescence intraoperatively. An experimental imaging device was used to image a total of 37 parathyroid glands. Scores of 0, 1 or 2 were assigned for ICG fluorescence by three observers based on perceived intensity: 0 for little to no fluorescence, 1 for moderate or patchy fluorescence, and 2 for strong fluorescence. Speckle contrast values were grouped according to these scores. Analyses of variance were performed to detect significant differences between groups. Lastly, ICG fluorescence intensity was calculated for each parathyroid gland and compared with speckle contrast in a linear regression. Results showed significant differences in speckle contrast between groups such that parathyroids with ICG score 0 had higher speckle contrast than those assigned ICG score 1, which in turn had higher speckle contrast than those assigned ICG score 2. This was further supported by a correlation coefficient of -0.81 between mean-normalized ICG fluorescence intensity and speckle contrast. This suggests that ICG angiography and LSCI detect similar differences in blood flow to parathyroid glands. Laser speckle contrast imaging shows promise as a label-free alternative that overcomes current limitations of ICG angiography for parathyroid assessment.

Efficacy of parathyroid autotransplantation in endoscopic total thyroidectomy with CLND

Purpose

To evaluate the safety and efficacy of autologous parathyroid transplantation in laparoscopic total thyroidectomy combined with central lymph node dissection (CLND).

Methods

Retrospective analysis of clinical data of 152 patients admitted to the General Surgery Department of Gansu Provincial People's Hospital who underwent endoscopic total thyroidectomy combined with CLND from June 2018 to December 2021. The intraoperative parathyroid glands were divided into the orthotopic preservation group (non-transplantation group) and the immediate active autologous transplantation group (transplantation group) according to the different treatment management of parathyroid glands during operation. The levels of Ca2+ in parathyroid blood and the incidence of hypoparathyroidism were compared between the two groups before operation and 1 day, 3 day, 1 week, 1 month, 3 months and 6 months after operation.

Results

There was no significant difference in PTH between the preoperative transplantation group compared and the non-transplantation group (P>0.05); The PTH in the transplantation group was lower than that of the non-transplantation group 1 and 3 d after surgery, and the difference was statistically significant (P<0.05); No statistically significant difference in PTH between patients in the transplantation group compared with those in the non-transplantation group at 1 week postoperatively (P>0.05); PTH was significantly higher in the transplant group than in the non-transplant group at 1, 3 and 6 months after surgery, with statistically significant differences (P<0.05); there was no statistically differences (P>0.05) in serum Ca2+ between the preoperative, 1d, 3d and 1 week postoperative transplantation group and the non-transplantation group; Blood Ca2+ was significantly higher in the transplant group than in the non-transplant group at 1, 3 and 6 months after surgery, with statistically significant differences (P<0.05); The rate of temporary hypoparathyroidism in the transplantion group was higher than that in the non-transplantion group, and the rate of permanent hypoparathyroidism was lower than that in the non-transplantion group (P=0.044); There was no significant difference in the concentration of PTH in the cephalic vein of the elbow between the transplanted side and the non-transplanted side at 1 day and 3 days postoperatively (P>0.05); the concentration of PTH in cephalic vein of the elbow was significantly higher than that in non-transplanted side at 1 week, 1 month, 3 months and 6 months postoperatively (P<0.001); the number central area dissection and metastasis dissection in the transplantation group were significantly higher than those in the non-transplantation group (P<0.05).

Conclusions

Most autologous parathyroid glands, having functional parathyroid autograft, is helpful to the occurrence of hypoparathyroidism after endoscopic total thyroidectomy with CLND, and it is an effective strategy to prevent permanent hypoparathyroidism, and more thorough area dissection is beneficial to the disease prognosis.

Preservation of parathyroid glands during thyroid and neck surgery

The parathyroid glands are situated in close proximity to the thyroid gland. They have an important endocrine function maintaining calcium and phosphate homeostasis in the body by the secretion of parathormone (PTH), which is responsible for this function. The parathyroid glands are commonly damaged during thyroid surgeries. This could lead to transient or permanent hypoparathyroidism in 30% of cases. Preservation of the parathyroid glands, is an important and integral part of thyroidectomy and other surgical interventions in the neck. The main principle underlying this is a thorough understanding of parathyroid anatomy in relation to the thyroid gland and other important structures in the area. There can also be significant variation in the anatomical location of the glands. Various techniques and methods have been described for parathyroid preservation. They include intraoperative identification utilizing indocyanine green (ICG) fluorescence, carbon nanoparticles, loupes, and microscopes. The techniques of surgery (meticulous capsular dissection), expertise, central compartment neck dissection, preoperative vitamin D deficiency, extent and type of thyroidectomy are the risk factors associated with damaged thyroids, inadvertent parathyroidectomy and subsequent hypoparathyroidism. Parathyroid Autotransplantation is a treatment option for inadvertent parathyroidectomy. Ultimately, the best way to assure normal parathyroid function is to preserve them in situ intraoperatively undamaged.

Long-Term Outcomes of Parathyroid Autografts in Primary Hyperparathyroidism

Context

Autologous implantation of parathyroid tissue is frequently utilized after parathyroidectomy in patients with heritable forms of primary hyperparathyroidism (PHPT). Data on long-term functional outcome of these grafts is sparse.

Objective

To investigate long-term outcomes of parathyroid autografts.

Methods

Retrospective study of patients with PHPT who underwent parathyroid autografts from 1991 to 2020.

Results

We identified 115 patients with PHPT who underwent 135 parathyroid autografts. Median follow-up duration since graft was 10 (4-20) years. Of the 111 grafts with known functional outcome, 54 (49%) were fully functional, 13 (12%) partially functional, and 44 (40%) nonfunctional at last follow-up. Age at time of graft, thymectomy prior to autograft, graft type (delayed vs immediate), or duration of cryopreservation did not predict functional outcome. There were 45 (83%) post-graft PHPT recurrences among 54 fully functional grafts at a median duration of 8 (4-15) years after grafting. Surgery was performed in 42/45 recurrences, but cure was attained in 18/42 (43%) only. Twelve of 18 (67%) recurrences were graft-related while remaining 6 (33%) had a neck or mediastinal source. Median time to recurrence was 16 (11-25) years in neck or mediastinal source vs 7 (2-13) years in graft-related recurrences. Median parathyroid hormone (PTH) gradient was significantly higher at 23 (20-27) in graft-related recurrence vs 1.3 (1.2-2.5) in neck or mediastinal source (P = .03).

Conclusions

Post-graft recurrence of PHPT occurs frequently within the first decade after graft and is challenging to localize. Time to recurrence after graft is significantly shorter and PTH gradient higher for graft-related recurrence. Clinical Trial Number: NCT04969926.

Autologous parathyroid gland left brachioradialis transplantation: A single-center study and long-term follow-up

Parathyroid gland transplantation into the sternocleidomastoid muscle is effective, but it is not possible to confirm transplant survival with this method. In this study, we evaluated parathyroid autotransplantation into the brachioradialis muscle and its survival rate.

OBJECTIVES

To evaluate autologous parathyroid gland left forearm brachioradial muscle transplantation and its survival rate.

SUMMARY BACKGROUND DATA

The most commonly used transplantation site is the sternocleidomastoid muscle, but transplant survival cannot be confirmed using this method. Autologous parathyroid gland left forearm brachioradial muscle transplantation solves this problem, and we evaluate the transplant survival using this method.

METHODS

We followed-up patients who underwent thyroidectomy and autologous parathyroid left forearm brachioradial muscle transplantation in our center from September 2013 to January 2018. The last follow-up date was January 2021; all enrolled patients underwent at least 3 years of follow-up. We calculated the transplant survival rate at several time points.

RESULTS

We evaluated 238 transplanted cases, for which the long-term survival rate was 85.7% (204/238), and the short-term survival rate was 86.1% (205/238). Sixty-five cases had two parathyroid glands transplanted into the left forearm brachioradialis muscle. The long-term survival rate was 92.3% (60/65), and the short-term survival rate was 95.4% (62/65).

CONCLUSIONS

Autologous parathyroid gland left brachioradialis transplantation is a reliable, measurable method with good survival rate, and we recommend this method for consideration for transplanting parathyroid glands in thyroidectomy.

Indocyanine Green Angiography of Parathyroid Glands versus Intraoperative Parathyroid Hormone Assay as a Reliable Predictor for Post Thyroidectomy Transient Hypocalcemia

BACKGROUND

Prediction of postoperative hypocalcemia is a fundamental issue in thyroidectomy. Indocyanine green (ICG) angiography of parathyroid glands is a feasible method to detect the perfusion of parathyroid glands and predict postoperative hypocalcemia.

MATERIALS AND METHODS

A prospective observational study was conducted at Ain Shams University Hospitals between April 2018 and April 2021. The included cases of total thyroidectomy underwent intraoperative ICG fluorescence angiography to identify the four parathyroid glands and score each gland according to the viability. Patients in which less than four glands were identified were excluded. Intraoperative intact parathyroid hormone (ioPTH) level assay was also measured to compare with ICG in predicting postoperative transient hypocalcemia.

RESULTS

A total of 134 cases underwent total thyroidectomy during the study period. We could identify the four parathyroid glands in 90 patients, including them in the study. We had postoperative hypocalcemia in 28 cases (31.1%). The diagnostic accuracy of ICG angiography and ioPTH level assay was high and almost similar (82.22% versus 87.78%). Both were higher than the surgeons' diagnostic accuracy of visual inspection (62.22%).

CONCLUSIONS

ICG angiography of the parathyroid gland is a safe, reliable predictor for postoperative transient hypocalcemia with a high and almost similar accuracy compared to intraoperative parathyroid hormone level.

Assessing Intraoperative Laser Speckle Contrast Imaging of Parathyroid Glands in Relation to Total Thyroidectomy Patient Outcomes

Background: Accurate assessment of parathyroid gland vascularity is important during thyroidectomy to preserve the function of parathyroid glands and to prevent postoperative hypocalcemia. Laser speckle contrast imaging (LSCI) has been shown to be accurate in detecting differences in parathyroid vascularity. In this surgeon-blinded prognostic study, we evaluate the relationship between intraoperative LSCI measurements and postoperative outcomes of total thyroidectomy patients. Methods: Seventy-two thyroidectomy patients were included in this study. After thyroid resection, an LSCI device was used to image all parathyroid glands identified, and a speckle contrast value was calculated for each. An average value was calculated for each patient, and the data were grouped according to whether the patient had normal (16-77 pg/mL) or low levels of parathyroid hormone (PTH) measured on postoperative day 1 (POD1). The aim of this study was to establish a speckle contrast threshold for classifying a parathyroid gland as adequately perfused and to determine how many such glands are required for normal postoperative parathyroid function. Results: A speckle contrast limit of 0.186 separated the normoparathyroid and hypoparathyroid groups with 87.5% sensitivity and 84.4% specificity: 7 of 8 patients with low PTH on POD1 had an average parathyroid speckle contrast above this limit, while 54 of 64 patients with normal postoperative PTH had an average parathyroid speckle contrast below this limit. Taking this value as the threshold for adequate parathyroid perfusion, it was determined that only one vascularized gland was needed for normal postoperative parathyroid function: 64 of 69 patients (92.8%) with at least one vascularized gland (determined by LSCI) had normal postoperative PTH, while all 3 patients (100%) with no vascularized glands had low postoperative PTH. Overall, the rates of temporary and permanent hypoparathyroidism in this study were 8.3% and 1.4%, respectively. Conclusions: LSCI is a promising technique for assessing parathyroid gland vascularity. It has the potential to help reduce the incidence of hypocalcemia after thyroidectomy by providing surgeons with additional information during surgery to aid in the preservation of parathyroid function.

Is There a Regular Pattern in the Recovery of Parathyroid Function After Thyroid Cancer Surgery?

Purpose

To investigate whether there is a pattern of recovery of parathyroid function after thyroid cancer surgery.

Patients and Methods

The study included 183 patients with papillary thyroid cancer (PTC) who underwent “total thyroidectomy (TT)” plus “unilateral central lymph node dissection (UCLND)” or “bilateral central lymph node dissection (BCLND)”. The intact parathyroid hormone (iPTH) and serum calcium (sCa) were analyzed several times within 1 month after surgery to explore the recovery pattern of parathyroid gland function. Then, these 183 cases were divided into group A (97 cases) with UCLND and group B (86 cases) with BCLND to analyze whether the impairment and recovery of parathyroid function were different between the two subgroups.

Results

Postoperative hypoparathyroidism was seen in 115 out of 183 cases. iPTH values decreased significantly on postoperative day (POD) 1 compared with preoperative values, dropped to the lowest point on POD 3, showed an increasing trend on POD 5 and 14, and increased to 85.0% of preoperative values at POD30, whereas changes in sCa differ from changes in iPTH, which showed the lowest sCa value on POD1, and rebounded on the POD3 with the intervention of calcium supplementation, and continued to rise on the POD5 and POD14, and the sCa value reached 96.6% of the preoperative level at POD30. Subgroup analysis showed that temporary hypoparathyroidism was more pronounced in group B than in group A. SCa and iPTH levels in both subgroups showed the same trend of first decrease and then increase.

Conclusion

The recovery of hypocalcemia and hypo-iPTHemia in the first month after thyroid cancer surgery shows a trend of decreasing and then increasing, and knowing the recovery of parathyroid function at different time points is of great value to surgeons and patients alike.

The Effect of Parathyroid Gland Autotransplantation on Hypoparathyroidism After Thyroid Surgery for Papillary Thyroid Carcinoma

Purpose

There are some controversies over the relationship between parathyroid gland autotransplantation and permanent hypoparathyroidism. This study aimed to explore the relationship between parathyroid gland autotransplantation and postoperative hypoparathyroidism.

Patients and Methods

We performed a retrospective analysis of patients who underwent initial thyroid surgery for papillary thyroid carcinoma from January 2014 to December 2018. Patients were divided into 4 groups according to the number of autotransplanted parathyroid glands (group 1: 0 autotransplanted parathyroid gland, group 2: 1 autotransplanted parathyroid gland, group 3: 2 autotransplanted parathyroid glands, group 4: 3 autotransplanted parathyroid glands). Clinical data were analyzed among the four groups.

Results

The more parathyroid glands were transplanted, the higher the incidence of immediate hypoparathyroidism was (group 1: 32.9%, group 2: 52.9%, group 3: 65.8%, group 4: 82.4%; P_{group 1 vs group 2} < 0.001, P_{group 2 vs group 3} = 0.012, P_{group 3 vs group 4} = 0.17). Parathyroid gland autotransplantation did not affect the incidence of permanent hypoparathyroidism (group 1: 1.4%, group 2: 1.3%, group 3: 0.9%, group 4: 0%; P_{group 1 vs group 2} > 0.99, P_{group 2 vs group 3} > 0.99, P_{group 3 vs group 4} > 0.99).

Conclusion

The number of autotransplanted parathyroid glands was positively associated with the incidence of postoperative immediate hypoparathyroidism. Parathyroid gland autotransplantation was not associated with permanent hypoparathyroidism.

Development of an imaging device for label-free parathyroid gland identification and vascularity assessment

During thyroid surgeries, it is important for surgeons to accurately identify healthy parathyroid glands and assess their vascularity to preserve their function postoperatively, thus preventing hypoparathyroidism and hypocalcemia. Near infrared autofluorescence detection enables parathyroid identification, while laser speckle contrast imaging allows assessment of parathyroid vascularity. Here, we present an imaging system combining the two techniques to perform both functions, simultaneously and label-free. An algorithm to automate the segmentation of a parathyroid gland in the fluorescence image to determine its average speckle contrast is also presented, reducing a barrier to clinical translation. Results from imaging ex vivo tissue samples show that the algorithm is equivalent to manual segmentation. Intraoperative images from representative procedures are presented showing successful implementation of the device to identify and assess vascularity of healthy and diseased parathyroid glands.

Tissue printing for engineering transplantable human parathyroid patch to improve parathyroid engraftment, integration, and hormone secretionin vivo

During thyroid surgery, some parathyroid glands fail to maintain their function, therefore, they are unavoidably detached from the patient. For the purpose of re-preservation of the function, they are minced into small segments and transplanted into the fat or muscle layer. Yet, this method of auto-grafting the parathyroid glands is frequently unsuccessful due to its poor interaction and engraftment with the native tissue, eventually leading to the dysfunction of the parathyroid hormone (PTH) secretion. In this study, we suggest a methodology to restore parathyroid activity through the introduction of the 'tissue printing' concept. Parathyroid glands of patients with secondary hyperparathyroidism were minced into the fragments smaller than 0.5 × 0.5 mm, which is in common with the traditional surgical method. These parathyroid tissues (PTs) were uniformly mixed with the adipose-derived decellularized extracellular matrix (adECM) bioink that protects the PTs from hostilein vivoenvironments and promote initial engraftment. PTs-encapsulated adECM bioink (PTs-adECM) was then printed onto the pre-designed polycaprolactone (PCL) mesh to produce patch-type PTs construct, which functions as a mechanical support to further enhance long-termin vivostability. The engineered patch was transplanted subcutaneously into rats and harvested after 4 weeks.In vivoresults showed that the engineered patches were well engrafted and stabilized in their original position for 4 weeks as compared with PTs only. Immunohistochemistry results further revealed that the concentration of PTH was approximately 2.5-fold greater in rats engrafted in the patch. Taken together, we envision that the novel concept 'tissue printing' over cell printing could provide a closer step towards clinical applications of 3D bioprinting to solve the unmet need for parathyroid surgery method.

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.

Preoperative Vitamin D Levels as a Predictor of Transient Hypocalcemia and Hypoparathyroidism After Parathyroidectomy

Hypocalcemia is a common problem after parathyroidectomy and/or thyroidectomy. The complication may be transient or permanent. Most cases occur as a result of removal of the parathyroid glands or damage to the glands during neck surgery. The purpose of this study was to evaluate the effect of preoperative vitamin D deficiency in predicting transient hypocalcemia and hypoparathyroidism after parathyroidectomy.Retrospective evaluation was made of 180 patients with primary hyperparathyroidism in respect of serum 25(OH)D, calcium and parathyroid hormone before and after parathyroidectomy. Transient hypocalcemia was defined as corrected calcium ≤ 8.4 mg/dL, and these cases were then evaluated for preoperative 25(OH)D values. Transient hypoparathyroidism has been described as low PTH level immediately after surgery before beginning any supplementation. Permanent hypoparathyroidism is accepted as the need for medical treatment is necessary over 12 months.Both transient hypocalcemia and hypoparathyroidism developed at statistically significantly higher rates in patients with preoperative vitamin D deficiency and vitamin D insufficiency.Vitamin D deficiency is an independent contributor to transient hypocalcemia and hypoparathyroidism following parathyroidectomy.

Prevalence and risk factors for hypoparathyroidism following total thyroidectomy in Spain: a multicentric and nation-wide retrospective analysis

PURPOSE

The prevalence of postoperative hypoparathyroidism has been studied in registries and in surgical series with highly variable and imprecise results. However, the frequency of this hormonal deficiency in the clinical practice of endocrinologists is not known with accuracy. We aimed to assess the prevalence and risk factors of hypoparathyroidism in patients undergoing total thyroidectomy in Spain.

METHODS

We designed a retrospective, multicentre and nation-wide protocol including all patients with total thyroidectomy who were seen in the endocrinology clinic of the participant centers from January to March 2018. Prevalence of hypoparathyroidism was evaluated at discharge of surgery, 3-6 months after surgery, 12 months after surgery and at last visit. Twenty hospitals participated in the study.

RESULTS

Of 1792 patients undergoing total thyroidectomy, 866 (48.3%) developed postoperative hypoparathyroidism at discharge of surgery. Most of them recover parathyroid function over time. Prevalence of hypoparathyroidism at 3-6 months, 12 months and at last visit was 22.9%, 16.7% and 14.5%, respectively. The risk of developing definitive hypoparathyroidism was related to the presence of parathyroid tissue at histology, lymph node dissection, and two-stage thyroidectomy. Patients with thyroid cancer, with higher postoperative calcium levels and treated by expert surgical teams exhibited lower risk of developing permanent hypoparathyroidism.

CONCLUSIONS

Although most patients with postsurgical hypoparathyroidism recover parathyroid function, the prevalence of permanent disease in clinical practice is non negligible (14.5%). Postoperative calcium, extent and timing of surgery, the presence of cancer, expert surgical team, and parathyroid tissue at histology are predictors of permanent hypoparathyroidism.

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.

Predicting transient hypocalcemia in patients with unplanned parathyroidectomy after thyroidectomy

OBJECTIVE

To assess the utility of rapid parathyroid hormone (PTH) values in predicting transient post-operative hypocalcemia in patients with unplanned parathyroidectomy during total or completion thyroidectomy.

METHODS

All patients who underwent total or completion thyroidectomy between January 2010 and January 2015 were reviewed. Incidences of post-operative hypocalcemia were compared in patients with and without unplanned parathyroidectomy. Unplanned parathyroidectomy was defined as intra-operative incidental or intentional parathyroidectomy. Logistic regression assessed for predictors of hypocalcemia and optimum amount of calcium supplementation.

RESULTS

Thirty-eight (13.6%) patients had evidence of incidental parathyroidectomy and 39/280 (13.9%) patients had parathyroid autotransplantation intra-operatively. Central neck dissection and malignancy were identified as risk factors for unplanned parathyroidectomy (p = 0.001, p = 0.060). Patients with unplanned parathyroidectomy were more likely to have hypocalcemia (p = 0.002) and hypoparathyroidism (p < 0.0005). PTH value was the only significant predictor of hypocalcemia in these patients. In patients with a post-operative PTH of ≤15, initial calcium supplementation ≥ 1000 mg decreased the risk of hypocalcemia (p < 0.05).

CONCLUSION

Post-operative PTH value predicts hypocalcemia in patients undergoing total and completion thyroidectomy with unplanned parathyroidectomy. In patients with a post-operative PTH < 15, initial calcium supplementation with ≥1000 mg of elemental calcium is recommended.

Parathyroid autotransplantation at a novel site for better evaluation of the grafted gland function: study protocol for a prospective, randomized controlled trial

Background

Hypoparathyroidism is one of the most common complications encountered in thyroidectomy. In addition to parathyroid in-situ preservation, parathyroid autotransplantation (PA) is another important remedial method for patients whose parathyroid glands have been removed. However, an accurate evaluation method for the function of a transplanted parathyroid is lacking. Our preliminary study indicated that patients with PA at novel sites near antecubital veins had higher serum concentrations of parathyroid hormone (PTH). Therefore, the main hypothesis is that a grafted site closer to the cephalic vein is more useful for better evaluation of transplanted parathyroid function. This study aims to confirm the more efficient and accurate evaluation system through a prospective, randomized controlled trial.

Methods

In total, 280 patients will be enrolled in this study and randomly divided into two groups: 140 patients with transplanted parathyroid glands in the traditional sites (group A) and the other 140 transplanted in the novel sites (group B), close to the antecubital veins. The serum concentration of PTH and calcium ion from both forearms will be measured and monitored regularly for 12 months. The primary outcome of this trial will be the survival of grafted glands, defined as the ratio of PTH between the grafted vs. the non-grafted forearms being no less than 1.5. The secondary outcome is hypoparathyroidism, defined as the PTH level from the non-grafted forearms being less than 15 pg/ml (normal range 15–65 pg/ml).

Discussion

Our results from this study should provide a more accurate method to evaluate the function of transplanted parathyroid glands by comparing PTH concentrations in both the grafted and non-grafted forearms following PA at novel sites. A better PTH measurement is helpful not only for the management of postoperative patients, but also for further identification of factors affecting PA success.

Trial registration

ClinicalTrials.gov, ID: NCT02906748. Registered on 16 March 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3195-9) contains supplementary material, which is available to authorized users.

Predictors of graft function after parathyroid autotransplantation during thyroid surgery

BACKGROUND

The purpose of this study was to identify predictors associated with graft function after parathyroid autotransplantation during thyroid surgery.

METHODS

One hundred fifty patients who underwent thyroid surgery with parathyroid autotransplantation were enrolled prospectively. During surgery, the misresected or devascularized parathyroid gland was autografted in the brachioradialis muscle of the forearm. Parathyroid hormone (PTH) levels in both arms were measured regularly after surgery. Patient age, sex, extent of surgery, and postoperative serum calcium levels were recorded.

RESULTS

Graft function was documented in 115 patients (76.7%). Univariate analysis revealed that graft function had a significant association with lower serum calcium level 1 day after surgery. The cutoff point was 2.11 mmol/L, which was confirmed by a receiver-operating characteristic (ROC) curve.

CONCLUSION

Low serum calcium levels in the early postoperative period may stimulate a functional recovery in an autografted parathyroid gland. Therefore, a moderate calcium supplement strategy was recommended for patients who underwent parathyroid autotransplantation during the early stage after total thyroidectomy.

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.

Parathyroid autotransplantation in thyroid surgery

BACKGROUND

Careful parathyroid gland dissection and in situ preservation was the time-honored approach to prevent parathyroid failure after total thyroidectomy. The relative success of parathyroid autotransplantation of hyperplastic parathyroid tissue in patients with renal or hereditary hyperparathyroidism did popularize the use of normal parathyroid tissue autografts during thyroidectomy to prevent permanent hypoparathyroidism. Proof of autograft function in this setting, however, is controversial.

PURPOSE

This narrative review aims at reviewing critically the current status of parathyroid autotransplantation during total thyroidectomy. It is also meant to analyze from the historical, methodological, and clinical points of view the claimed benefit of normal parathyroid gland autotransplantation. A focus is placed on the prevention of permanent hypoparathyroidism by parathyroid autotransplantation.

CONCLUSIONS

Liberal parathyroid autotransplantation was proposed in the mid 1970s but evidence of function is scarce. Proofs are accumulating that parathyroid autografts not only increase the rate of postoperative hypocalcemia, but may be also contribute to permanent hypoparathyroidism.

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.).

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.

Intraoperative Assessment of Parathyroid Viability using Laser Speckle Contrast Imaging

Post-surgical hypoparathyroidism and hypocalcemia are known to occur after nearly 50% of all thyroid surgeries as a result of accidental disruption of blood supply to healthy parathyroid glands, which are responsible for regulating calcium. However, there are currently no clinical methods for accurately identifying compromised glands and the surgeon relies on visual assessment alone to determine if any gland(s) should be excised and auto-transplanted. Here, we present Laser Speckle Contrast Imaging (LSCI) for real-time assessment of parathyroid viability. Taking an experienced surgeon's visual assessment as the gold standard, LSCI can be used to distinguish between well vascularized (n = 32) and compromised (n = 27) parathyroid glands during thyroid surgery with an accuracy of 91.5%. Ability to detect vascular compromise with LSCI was validated in parathyroidectomies. Results showed that this technique is able to detect parathyroid gland devascularization before it is visually apparent to the surgeon. Measurements can be performed in real-time and without the need to turn off operating room lights. LSCI shows promise as a real-time, contrast-free, objective method for helping reduce hypoparathyroidism after thyroid surgery.

Parathyroid reimplantation with PR-FaST technique in unselected patients during thyroidectomy. A case series with long term follow up confirming graft vitality and parathormone production

INTRODUCTION

Parathyroid damage or unintentional excision still affect thyroid surgery and may cause permanent hypoparathyroidism. The only way to recover the excised or ischemic gland functionality is still reimplantation. Many sites of reimplantation have been described, each of one showing both advantages and drawbacks. The aim of this study is to verify results of a new procedure called PR-FaST: Parathyroid Reimplantation in Forearm Subcutaneous Tissue, in a series of unselected patients after long-term follow-up.

MATERIALS AND METHODS

From January 2013 to October 2015, 296 consecutive total thyroidectomies have been performed) to treat both benign and malignant thyroid diseases. in 42 cases (14.1%), due to an insufficient blood supply or accidental removal, one parathyroid gland was reimplanted with the PR-FaST technique. Post-operative evaluation was carried out by: total serum calcium (Ca), magnesium (Mg) and phosphorus (P) analysis in the 1st and 2nd postoperative days; Ca, Mg, P and serum iPTH from both arms analysis one week after surgery; Ca and iPTH measurement from both arms 1 months, 3, 6 and 12 months after surgery.

RESULTS

We observed transient hypocalcemia requiring calcium replacement therapy in 5 on 42 (11.9%) patients submitted to PR-FaST. No case of permanent hypoparathyroidism was reported. At 1 week after surgery, only 20 patients (47.6%) showed graft vitality, while the number of patients showing graft vitality arised to 33 (79%) after 1 month and to 39 (92.8%) after three and six months. At 1 year 38 (90.5%) patients showed good graft functionality. Considering levels of serum iPTH from both arms, we observed that in case of graft functionality, samples from reimplanted arm revealed in almost all cases values at least 2-3 folds higher than in non reimplanted arm.

CONCLUSIONS

Results from this prospective evaluation suggest that PR-FaST is a safe and effective procedure, with potential advantages when compared to other techniques of parathyroid reimplantation, that are mainly the possibility to evaluate graft functionality in the follow-up and the easy and well reproducible technique. Furthermore, it can be applied, when needed, to potentially all patients undergoing thyroidectomy.

Failure of fragmented parathyroid gland autotransplantation to prevent permanent hypoparathyroidism after total thyroidectomy

PURPOSE

Parathyroid autotransplantation during total thyroidectomy leads to higher rates of postoperative hypocalcaemia. It has been argued, however, that it prevents permanent hypoparathyroidism. The impact of autografted normal parathyroid gland fragments on long-term parathyroid status has not been assessed properly. To clarify this, the short- and long-term parathyroid function was assessed in patients with three glands remaining in situ after total thyroidectomy, in whom the fourth gland was either autotransplanted (Tx) or accidentally resected (AR).

METHODS

Consecutive patients (n = 669) undergoing first-time total thyroidectomy were prospectively studied recording the number of parathyroid glands remaining in situ: PGRIS =4-(glands autografted + glands in the specimen). The study was focused on the subgroup of 186 patients with three parathyroid glands remaining in situ as a result of either accidental resection (AR, n = 76) or autotransplantation into the sternocleidomastoid muscle (Tx, n = 110). Prevalence of postoperative hypocalcaemia, protracted, and permanent hypoparathyroidism were compared between the two groups. Demographic, disease-related, laboratory, and surgical variables were recorded. All patients were followed for at least 1 year.

RESULTS

Both groups were comparable in terms of disease and extent of surgery. Mean postoperative serum calcium was the same (AR: 1.97 ± 0.2 vs Tx: 1.97 ± 0.22 mmol/L). Rates of protracted (AR: 24% vs Tx: 25.5%) and permanent hypoparathyroidism (AR: 5.3% vs Tx: 7.3%) were similar in both groups.

CONCLUSIONS

The prevalence of parathyroid failure syndromes after total thyroidectomy was similar whether a parathyroid gland was inadvertently excised or autotransplanted. Autotransplantation did not influence the permanent hypoparathyroidism rate.

Parathyroid Reimplantation in Forearm Subcutaneous Tissue During Thyroidectomy: A Simple and Effective Way to Avoid Hypoparathyroidism

INTRODUCTION

Parathyroid autotransplantation plays an important role in preventing hypoparathyroidism following thyroidectomy. The preferred reimplantation site is still the sternocleidomastoid muscle, but this approach does not permit to check graft vitality postoperatively. The authors report the first prospective evaluation of normal parathyroid gland reimplantation in forearm subcutaneous tissue (using the same technique proposed during parathyroidectomy for hyperplasia) in case of devascularized or inadvertently removed glands during thyroid surgery.

MATERIALS AND METHODS

From January 2013 to August 2014, we performed 348 consecutive thyroidectomies for various disease, both benign and malignant. In 25 cases, due to inadvertent parathyroid removal or evidence of insufficient blood supply, we removed and fragmented the gland into 0.5-1 mm slices (one for frozen section) and reimplanted it into two subcutaneous pockets on the non-dominant forearm. After surgery we checked grafted gland function by evaluation of serum parathormone gradient between reimplanted versus non-reimplanted arm (considering significant a ratio of 1.5 or more), at 1 week, 1 and 3 months after surgery.

RESULTS

We observed recovery of reimplanted graft function in 48, 88 and 96% of patients respectively at 1 week, 1 and 3 months after surgery. All patients showed normal parathormone levels in peripheral blood (non-reimplanted arm). In one case we observed post-operative wound hematoma on graft-site. This patient showed no graft functionality in post-operative period (even at 3 months follow-up).

CONCLUSIONS

Parathyroid gland reimplantation in forearm subcutaneous tissue during thyroid surgery is a safe, easy and effective procedure; furthermore, it allows a good control of graft functionality and would allow an easy grafted gland removal if needed.

Autotransplantation of parathyroid grafts into the tibialis anterior muscle after parathyroidectomy: a novel autotransplantation site

Background

Surgical management of renal secondary hyperparathyroidism (sHPT) is varying. Total parathyroidectomy with heterotopic autotransplantation (TPTX + AT) is one of the standard surgical procedures in sHPT, but there is no consensus about the optimal site for graft insertion. At the surgical department of the University Hospital of Heidelberg we prefer the autotransplantation into the tibialis anterior muscle. The aim of this study was to assess the long-term function of the auto-transplanted parathyroid tissue in this type of surgical procedure.

Methods

The function of the autograft of 42 patients was assessed 8.2 ± 2.5 years after surgery, using a modified Casanova-test of the leg bearing the parathyroid tissue. Ischemic blockage was induced by tourniquet and the levels of parathyroid hormone (PTH) were assessed during the test.

Results

At the point of assessment, the ischemic blockage led to a significant reduction in the concentration of PTH (≥50 % of the baseline value) in 19 patients (45 %) indicating well-functioning autografts. In 11 patients (26 %), ischemic blockage did not cause any change in the concentration of PTH (≤20 % of the baseline value), indicating functioning residual parathyroid tissue from another site. The source of PTH production was classified as unidentifiable in five patients (12 %). Two patients had developed graft-dependent recurrent HPT (5 %) without therapeutic consequences and three patients suffered from persistent symptomatic hypoparathyroidism (7 %).

Conclusions

These results indicate that TPTX + AT into the tibialis anterior muscle is a successful surgical treatment for renal HPT and that the modified Casanova-test is a suitable diagnostic tool for autografts function.

The risk of hypocalcemia in patients with parathyroid autotransplantation during thyroidectomy

OBJECTIVE

Thyroidectomy is the most common cause of hypocalcemia. Preservation of parathyroid glands in situ is essential in preventing this complication. The aims of our study were to review patients who underwent parathyroid gland autotransplantation during thyroidectomy, and to compare hypocalcemia rates in patients with and without autotransplantation.

MATERIAL AND METHODS

Parathyroid gland autotransplantation was performed in 43 (7.9%) of 543 patients who underwent thyroidectomy between 2008 and 2012.

RESULTS

Forty-four parathyroid glands were autotransplanted in 43 patients, including 36 women and 7 men. The median age was 55 (range: 30 to 68). The most common cause of autotransplantation was vascular comprise of the parathyroid gland. Early postoperative hypocalcemia developed in 37% of patients with autotransplantation, and none developed permanent hypocalcemia. Transient and permanent hypocalcemia rates were 9.6% and 0.4% in patients without autotransplantation, respectively. The risk of transient hypocalcemia was significantly high in patients with parathyroid autotransplantation (p<0.001). There was no difference between the two groups in terms of permanent hypocalcemia (p=0.156).

CONCLUSION

Despite meticulous dissection, parathyroid glands can be devascularized or removed inadvertently during thyroidectomy. Parathyroid autotransplantation is the best method to maintain parathyroid gland function. Although the risk of transient hypocalcemia is increased following parathyroid autotransplantation, long-term results are satisfactory.

The risk of hypocalcemia in patients with parathyroid autotransplantation during thyroidectomy

OBJECTIVE

Thyroidectomy is the most common cause of hypocalcemia. Preservation of parathyroid glands in situ is essential in preventing this complication. The aims of our study were to review patients who underwent parathyroid gland autotransplantation during thyroidectomy, and to compare hypocalcemia rates in patients with and without autotransplantation.

MATERIAL AND METHODS

Parathyroid gland autotransplantation was performed in 43 (7.9%) of 543 patients who underwent thyroidectomy between 2008 and 2012.

RESULTS

Forty-four parathyroid glands were autotransplanted in 43 patients, including 36 women and 7 men. The median age was 55 (range: 30 to 68). The most common cause of autotransplantation was vascular comprise of the parathyroid gland. Early postoperative hypocalcemia developed in 37% of patients with autotransplantation, and none developed permanent hypocalcemia. Transient and permanent hypocalcemia rates were 9.6% and 0.4% in patients without autotransplantation, respectively. The risk of transient hypocalcemia was significantly high in patients with parathyroid autotransplantation (p<0.001). There was no difference between the two groups in terms of permanent hypocalcemia (p=0.156).

CONCLUSION

Despite meticulous dissection, parathyroid glands can be devascularized or removed inadvertently during thyroidectomy. Parathyroid autotransplantation is the best method to maintain parathyroid gland function. Although the risk of transient hypocalcemia is increased following parathyroid autotransplantation, long-term results are satisfactory.

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.

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.

Islet survival and function following intramuscular autotransplantation in the minipig

The liver may not be an optimal site for islet transplantation due to obstacles by an instant blood-mediated inflammatory response (IBMIR), and low revascularization of transplanted islets. Therefore, intramuscular islet transplantation (IMIT) offers an attractive alternative, based on its simplicity, enabling easier access for noninvasive graft imaging and cell explantation. In this study, we explored the outcome of autologous IMIT in the minipig (n = 30). Using the intramuscular injection technique, we demonstrated by direct histological evidence the rapid revascularization of islets autotransplanted into the gracilius muscle. Islet survival assessment was performed using immunohistochemistry staining for insulin and glucagon up to a period of 6 months. Furthermore, we showed the crucial role of minimizing mechanical trauma to the myofibers and limiting exocrine contamination. Intramuscular islet graft function after transplantation was confirmed by documenting the acute insulin response to intravenous glucose in 5/11 pancreatectomized animals. Graft function after IMIT remained however significantly lower than the function measured in 12 out of 18 minipigs who received a similar islet volume in the liver through intraportal infusion. Collectively, these results demonstrated in a clinically relevant preclinical model, suggest IMIT as a promising alternative to intraportal infusion for the transplantation of β cells in certain medical situations.

Outcome of protracted hypoparathyroidism after total thyroidectomy

BACKGROUND

Although the variables that influence the development of post-thyroidectomy hypocalcaemia are now better understood, the risk factors and long-term outcome of persistent hypoparathyroidism (HPP) are poorly defined. A retrospective review of a prospective protocol for the management of post-thyroidectomy hypocalcaemia was performed.

METHODS

Patients with a serum calcium level below 8 mg/dl (2 mmol/l) 24 h after total thyroidectomy were prescribed oral calcium with or without calcitriol and followed for at least 1 year. Protracted HPP was defined as an intact parathyroid hormone (iPTH) level below 13 pg/ml and need for calcium medication at 1 month after thyroidectomy.

RESULTS

Of 442 patients (343 with goitre, 99 with carcinoma) undergoing total thyroidectomy, 222 (50.2 per cent) developed postoperative hypocalcaemia. Eleven patients were lost to follow-up. Parathyroid function recovered in 131 patients within 1 month and 80 developed protracted HPP, which was associated with lymphadenectomy, fewer than three glands left in situ and incidental parathyroidectomy. Parathyroid function recovered within 1 year in 78 per cent of patients with protracted HPP. Factors associated with late recovery of parathyroid function were higher serum calcium and low but detectable iPTH levels 1 month after surgery. These factors were associated with higher calcitriol and calcium dosages at hospital discharge. Parathyroid autotransplantation did not protect against permanent HPP.

CONCLUSION

Higher serum calcium levels at 1 month after total thyroidectomy are associated with recovery of parathyroid function. It is hypothesized that intensive medical treatment of hypocalcaemia-'parathyroid splinting'-may improve the outcome of patients with protracted HPP.

Parathyroid gland preservation and selective autotransplantation utilizing topical lidocaine in total thyroidectomy

OBJECTIVES/HYPOTHESIS

To review a new technique during total thyroidectomy that facilitates parathyroid gland preservation and selective autotransplantation utilizing topical 2% plain lidocaine as a spasmolytic/vasodilator agent.

STUDY DESIGN

Retrospective case series review at a university hospital.

METHODS

The study population comprised 100 consecutive patients (84 women and 16 men; mean age, 52 years) undergoing total thyroidectomy from January 2007 to December 2008. Interventions were: parathyroid glands (PGs) with signs of devascularization treated with a topical solution of 2% plain lidocaine in an attempt to restore blood flow before committing to autotransplantation.

RESULTS

The main outcome measure was the incidence of hypoparathyroidism. A total of 40 parathyroid glands were autotransplanted. None of the 100 patients developed permanent hypoparathyroidism. There were no adverse effects utilizing this technique.

CONCLUSIONS

In our experience, the use of lidocaine spasmolysis is a useful technique in thyroid surgery for salvaging devascularized PGs. Its utility as a selection method for PG autotransplantation incurs minimal risk or cost and might further reduce the incidence of permanent hypoparathyroidism. Further study is warranted.

Total parathyroidectomy and autotransplantation by the subcutaneous injection technique in secondary hyperparathyroidism

PURPOSE

To prospectively assess the effectiveness of total parathyroidectomy and autotransplantation using a subcutaneous injection technique to treat secondary hyperparathyroidism.

METHODS

We used this method to treat 14 patients with secondary hyperparathyroidism. The short-term outcome, up to 16 months after surgery, was monitored by measuring calcium, inorganic phosphorus, intact parathyroid hormone (iPTH), and alkaline phosphatase levels. We considered a graft viable when the ratio of iPHT in antecubital venous blood from the grafted arm to that from the nongrafted arm exceeded 1.5.

RESULTS

Autografted parathyroid tissue was functional in 12 (85.7%) patients. An iPTH ratio > or =1.5 in the grafted arm relative to the nongrafted arm was observed from 2 weeks after surgery, peaking at 1 month. The grafted tissue continued to be biochemically functional 16 months after surgery in 12 patients.

CONCLUSION

These findings suggest that total parathyroidectomy and forearm autotransplantation using the subcutaneous injection technique is a possible alternative to Wells' method for surgical treatment of secondary hyperparathyroidism.

Intraoperative Intact Parathyroid Hormone Level Monitoring as a Guide to Parathyroid Reimplantation after Thyroidectomy

OBJECTIVE

The goal of this study was to determine whether intraoperative intact parathyroid hormone (IOiPTH) levels can predict the functional status of remaining parathyroids at the end of total thyroidectomy and thereby be a guide for parathyroid autotransplantation when glands are deemed not functional.

STUDY DESIGN

Prospective study involving 23 patients undergoing either total thyroidectomy or completion thyroidectomy

METHODS

During surgery, an attempt was made to identify all four parathyroid glands. Normal size vascular glands were preserved, whereas avascular glands were microdissected and reimplanted. Serial IOiPTH was measured preoperatively after each parathyroid was identified, manipulated, or removed and serum iPTH measurements were done postoperatively up to 56 days.

RESULTS

The sensitivity of low IOiPTH in identifying a devascularized gland was 88.9%, and specificity was 92.9%. A normal IOiPTH level indicates at least two functioning glands. IOiPTH levels between 1.5 and 10 pg/mL indicate only one functional gland. Undetectable IOiPTH levels indicate no residual functioning gland.

CONCLUSIONS

For patients undergoing total or completion thyroidectomy, IOiPTH should be routinely measured at the end of the procedure, and a level less than 10 pg/mL requires reassessment of remaining parathyroid glands. Vascularized glands should be preserved regardless of IOiPTH levels. Devascularized glands or glands of questionable vascularity should be considered for autotransplantation.

[Hypoparathyroidism and hypocalcemia following thyroid surgery of multinodular goiter. Multivariant study of the risk factors]

BACKGROUND AND OBJECTIVE

The hypoparathyroidism is one of the most important complications in the patients submitted to thyroid surgery. The aim is to analyze across a multivariate statistical analysis the risks factors for the development of transient and permanent hypoparathyroidism following the multinodular goiter (MG) surgery.

PATIENTS AND METHOD

Between 1970 and 1999, 672 thyroidectomies by MG were reviewed. It was considered transient hypoparathyroidism when the calcemia was minor of 7.5 mg/dl or when being minors of 8.5 mg/dl the patient was presenting symptomatology for the hipocalcemia. The hypoparathyroidsm was considered permanent when the calcemia was minor of 8.5 mg/dl to the year of the surgery.

RESULTS

The hypoparathyroidism appeared in 75 patients (11.2%), 20 with symptomatology (3%), persisting like permanent 6 cases (0.9%). The risk factors for the development of this were the hyperthyroidism (p = 0.0370), and the surgical technique (p < 0.00001) (unilateral versus bilateral surgery), persisting in the multivariate analysis both variables. With respect to the permanent hypoparathyroidism, the risk factor was the toxic MG (p = 0.0109), persisting as independent risk factor in the multivariate analysis (RR = 2.3).

CONCLUSIONS

The principal risk factor of permanent hypoparathyroidism in the MG surgery is the presence of hyperthyroidism.

Complications of thyroid and parathyroid surgery

Today most complications of thyroid and parathyroid surgery are related to either metabolic derangements or injury to the recurrent laryngeal nerves. Other complications include superior laryngeal nerve injury, infection, airway compromise, and bleeding. Although the principal goal of thyroid and parathyroid surgery is the prevention of these complications, prompt recognition and intervention will minimize morbidity and provide the patient with the best chance of a satisfactory outcome.