Five to 10 years follow-up after total parathyroidectomy and autotransplantation of parathyroid tissue: evaluation of parathyroid function by use of ischaemic blockade manoeuvre

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.

Medical and Surgical Treatment for Secondary and Tertiary Hyperparathyroidism

Prevention and treatment of secondary hyperparathyroidism (SHPT) in patients on chronic maintenance hemodialysis and of tertiary hyperparathyroidism (THPT) in patients after kidney transplantation is a challenge for the nephrologist and for the surgeon. Indication and results of medical and surgical therapy for SHPT and THPT have remained under discussion during the last decades. This review resumes the current medical and surgical strategies for patients with SHPT and THPT.

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.

Surgical approach in patients with hyperparathyroidism in multiple endocrine neoplasia type 1: total versus partial parathyroidectomy

Usually, primary hyperparathyroidism is the first endocrinopathy to be diagnosed in patients with multiple endocrine neoplasia type 1, and is also the most common one. The timing of the surgery and strategy in multiple endocrine neoplasia type 1/hyperparathyroidism are still under debate. The aims of surgery are to: 1) correct hypercalcemia, thus preventing persistent or recurrent hyperparathyroidism; 2) avoid persistent hypoparathyroidism; and 3) facilitate the surgical treatment of possible recurrences. Currently, two types of surgical approach are indicated: 1) subtotal parathyroidectomy with removal of at least 3-3 K glands; and 2) total parathyroidectomy with grafting of autologous parathyroid tissue. Transcervical thymectomy must be performed with both of these procedures. Unsuccessful surgical treatment of hyperparathyroidism is more frequently observed in multiple endocrine neoplasia type 1 than in sporadic hyperparathyroidism. The recurrence rate is strongly influenced by: 1) the lack of a pre-operative multiple endocrine neoplasia type 1 diagnosis; 2) the surgeon's experience; 3) the timing of surgery; 4) the possibility of performing intra-operative confirmation (histologic examination, rapid parathyroid hormone assay) of the curative potential of the surgical procedure; and, 5) the surgical strategy. Persistent hyperparathyroidism seems to be more frequent after subtotal parathyroidectomy than after total parathyroidectomy with autologous graft of parathyroid tissue. Conversely, recurrent hyperparathyroidism has a similar frequency in the two surgical strategies. To plan further operations, it is very helpful to know all the available data about previous surgery and to undertake accurate identification of the site of recurrence.

Metastatic Colon Cancer to the Thyroid Gland in the Setting of Pathologically Diagnosed Papillary Thyroid Cancer: A Review and Report of a Case

Colon carcinoma metastases to the thyroid are a rare phenomena. Here we report a case of multiple malignant neoplasms where an incidental diagnosis of colon cancer was made after pathologic evaluation of the thyroid specimen.

[Evaluation of parathyroid function in presternal subcutaneous grafting after total parathyroidectomy for renal hyperparathyroidism]

INTRODUCTION

In the setting of total parathyroidectomy (TPT) and parathyroid transplantation (PTx) for renal hyperparathyroidism (RHP), we evaluated long-term parathyroid graft function after subcutaneous presternal transplantation (SCPTx).

HYPOTHESIS

Parathyroid glands are surrounded by fatty tissue. Therefore, we postulated that subcutaneous implantation of parathyroid tissue after TPT for RHP could be at least as effective as intramuscular grafting and would avoid the complications of the latter technique.

MATERIAL AND METHOD

We performed a study in a university hospital and its dialysis unit.

DESIGN

Prospective open efficacy study of a postoperative diagnostic monitoring method of intact parathyroid hormone (iPTH) in a cohort of surgical patients without loss to follow-up.

PATIENTS AND INTERVENTIONS

Thirty-five patients (19 women and 16 men) underwent TPT and SCPTx for RHP at the Department of General Surgery and Department of Nephrology, Donostia Hospital, San Sebastián, Gipuzkoa, Spain, from January 2002 to December 2005. Follow-up ranged from 6 to 42 months (mean, 15.4 months). Graft function was evaluated by measurement of plasma iPTH levels before surgery and 24 hours and 1, 3, 5, 15, 30, 60, 100 and 150 weeks after surgery. Reference values for PTH in our laboratory were 20-65 pg/mL.

RESULTS

The mean preoperative iPTH values were 1245 +/- 367.9 pg/mL (mean +/- SD) (range, 493-2160). After TPT and SCPTx, iPTH levels became undetectable in all patients at 24 hours. A value of 50 pg/mL was established as the criterion for adequate parathyroid graft function. The following values were obtained: 15.54 +/- 10.61 pg/mL (mean +/- SD) (range, 6-44) after 1 week, 57.2 +/- 1.9 pg/mL (mean +/- SD) (range, 43-74) after 5 weeks, 64.21 +/- 9.73 pg/mL (mean +/- SD) (range, 11.3-89) after 15 weeks, 75.12 +/- 9.05 pg/mL (mean +/- SD) (range, 24.6-104.2) after 30 weeks, 101.63 +/- 19.85 pg/mL (mean +/- SD) (range, 65-143) after 60 weeks, 121.63 +/- 27.85 pg/mL (mean +/- SD) (range, 62-179) after 100 weeks, 63 +/- 19.85 pg/mL (mean +/- SD) (range, 68-723) after 150 weeks and 102 +/- 18.65 pg/mL (mean +/- SD) (range, 68-113) after 200 weeks. The prevalence of hypoparathyroidism (serum iPTH level of < 20 pg/mL with a normal or low serum calcium concentration) was 2 out of 35 patients (5.71%) by week 60, with recovery of normal values by week 100. Graft-related recurrence occurred in one out of 35 patients (2.85%).

CONCLUSIONS

SCPTx after TPT and PTx for secondary RHP is an adequate method to replace muscular forearm parathyroid transplantation and avoid its complications. The functional results of TPT and SCPTx compare favorably with published data on other surgical techniques proposed for the treatment of RHP. Long-term follow-up of this series is currently being performed.

Parathyroid Subcutaneous Pre-sternal Transplantation after Parathyroidectomy for Renal Hyperparathyroidism. Long-term Graft Function

BACKGROUND

In the setting of total parathyroidectomy (TPT) and parathyroid transplantation (PTx) for renal hyperparathyroidism (RHP), we evaluated long-term parathyroid graft function after subcutaneous pre-sternal transplantation (SCPTx). Because parathyroid glands are surrounded by fatty tissue, we postulated that results of subcutaneous implantation of parathyroid tissue after total parathyroidectomy for renal hyperparathyroidism could be at least as successful as intramuscular grafting, but without its complications.

PATIENTS AND METHODS

The study, a prospective open efficacy study of postoperative (po) diagnostic monitoring of intact parathyroid hormone (iPTH) on a cohort of surgical patients, was conducted within a university hospital with a dialysis unit. Thirty five patients (19 women and 16 men) operated on for renal hyperparathyroidism underwent TPT and SCPTx for RHP at the Department of General Surgery and the Department of Nephrology. Donostia Hospital. San Sebastián. Gipuzkoa. Spain, from January 2002 to December 2005. Follow-up ranges from 6 months to 42 months (median: 15.4 months). The main outcome measure was evaluation of graft function by measurement of iPTH plasma level, based on serum levels of iPTH before operation and 24 h and 1, 3, 5, 15, 30, 60, 100, and 150 weeks after surgery.

RESULTS

Average preoperative iPTH values were 1,341.52 + 367.78 pg/ml (mean +/- SD) (range: 493-2,180). After TPT and PSCTx, iPTH levels became undetectable in all patients at 24 h. A level of 50 pg/ml was established as the criterion of adequate parathyroid graft function. Values obtained at the various time intervals were as follows: 14.14 + 7.73 1 pg/ml (mean +/- SD) (range: 6-36) after 1 week, 53 + 77.33 pg/ml (mean +/- SD) (range: 35-74) after 5 weeks, 62.95 + 20.93 pg/ml (mean +/- SD) (range: 11-89) after 15 weeks, 77.54 + 18.84 pg/ml (mean +/- SD) (range: 24.6-104.2) after 30 weeks, 109.29 + 50.22 pg/ml (mean +/- SD) (range: 54-327) after 60 weeks, 134.21 + 128.64 pg/ml (mean +/- SD) (range: 43-712) after 100 weeks, and 122.84 + 117.54 pg/ml (mean +/- SD) (range: 68-723) after 150 weeks. Prevalence of hypoparathyroidism (intact parathyroid hormone serum level < 20 pg/ml with a normal or low serum calcium concentration) was 2/35 (5.71%) by week 60 and recovered by week 100. Graft-related recurrence was 2.85% (1/35).

CONCLUSIONS

Subcutaneous pre-sternal transplantation (SCPTx) after TPT and PTx for secondary (RHP) is an adequate method to replace muscular forearm parathyroid transplantation and avoid its complications. Functioning results of total parathyroidectomy and presternal subcutaneous grafting compare favorably with the published data on other surgical techniques proposed for the treatment of renal hyperparathyroidism. Results of long-term follow-up exceed previously reported results.

Parathyroid surgery in familial hyperparathyroid disorders

The management of hyperparathyroidism (HPT) in the setting of familial HPT differs between the specific syndromes and is generally complex because of the underlying disease, which predisposes patients to persistent and recurrent HPT. The basic principles of surgery include achieving and maintaining normocalcaemia for the longest time possible, avoiding both iatrogenic hypocalcaemia and operative complications, and facilitating future surgery for recurrent disease. Multiple endocrine neoplasia type 1 (MEN1) is treated with either subtotal parathyroidectomy or total parathyroidectomy with immediate heterotopic autotransplantation of parathyroid tissue. MEN2A, familial isolated HPT and HPT-associated with the hyperparathyroidism-jaw tumour (HPT-JT) syndrome typically can be treated with parathyroidectomy, i.e. subtotal or less. The increased risk of parathyroid cancer in HPT-JT requires special attention. Parathyroid surgery in familial HPT syndromes in the setting of underlying mutations in the calcium receptor (CASR) gene involves radical subtotal parathyroidectomy. Intraoperative parathyroid hormone (PTH) measurements may help guide the extent of parathyroid resection, particularly in the case of multigland HPT. The vast majority of patients with familial HPT who require surgery are best served with bilateral cervical explorations. However, minimally invasive parathyroidectomy (MIP) techniques that have become routine for sporadic HPT at selected institutions may be extrapolated to a subset of cases of familial HPT.

Tc-99m-MIBI scintigraphy for recurrent hyperparathyroidism after total parathyroidectomy with autograft

The aim of this study is to assess the sensitivity of Tc-99m-MIBI for the pre-operative localization of hyperfunctioning parathyroid glands in patients with persistent or recurrent hyperparathyroidism (HPT) after total parathyroidectomy (PTX) with autograft.

PATIENTS AND METHODS

Tc-99m-MIBI scintigraphy was performed on 7 patients (3 men and 4 women; aged 32 to 62) on hemodialysis with persistent or recurrent HPT after PTX due to secondary hyperparathyroidism. Tc-99m-MIBI of 370 MBq was injected intravenously. Double-phase planar images were acquired at 15 min and 120 min-postinjection. SPECT images of the chest in an early phase were also obtained.

RESULTS

All patients underwent surgery after scintigraphy. The enlarged parathyroid grafts were removed in 4 patients. An unusual location of parathyroid hyperplasia was found in 2 patients. In one patient, the abnormal graft coexisted with an ectopic parathyroid in the mediastinal region. Tc-99m-MIBI was able to identify all hyperfunctioning parathyroids correctly (100% sensitivity). In one case, a focus of the increased uptake in SPECT was considered as a false positive. The remnant of ectopic parathyroid in the mediastinum was only detected by SPECT images.

CONCLUSION

Tc-99m-MIBI parathyroid scintigraphy is useful for the pre-operative localization of persistent or recurrent HPT following total PTX with autograft.