Surgical management of secondary hyperparathyroidism in uremia

Hyperparathyroidism of Renal Disease

Renal hyperparathyroidism (rHPT) is a common complication of chronic kidney disease characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Patients with rHPT experience increased rates of cardiovascular problems and bone disease. The Kidney Disease: Improving Global Outcomes guidelines recommend that screening and management of rHPT be initiated for all patients with chronic kidney disease stage 3 (estimated glomerular filtration rate, < 60 mL/min/1.73 m(2)). Since the 1990s, improving medical management with vitamin D analogs, phosphate binders, and calcimimetic drugs has expanded the treatment options for patients with rHPT, but some patients still require a parathyroidectomy to mitigate the sequelae of this challenging disease.

Long-term prognosis of parathyroid function in chronic dialysis patients after PEIT-a single-centre trial

Background. Secondary hyperparathyroidism (SHPT) is a common complication observed in long-term dialysis patients. Percutaneous ethanol injection therapy (PEIT) of parathyroid glands (PTGs) is now established in Japan as a treatment option for SHPT. In this study, to elucidate the factors influencing efficacy in 1 year and relapse following PEIT, we analysed the long-term prognosis of parathyroid function that is known to have the greatest effect on therapeutic results.

Methods. The study design was a retrospective cohort study. We studied 104 patients with SHPT, who underwent PEIT at Tokai University Hospital between January 1993 and December 2002, and we followed them up until January 2008. The effective group reached intact parathyroid hormone of 200 pg/ml or less, corrected calcium (Ca) of 10.5 mg/dl or less and phosphate (P) of 6.0 mg/dl or less. The ineffective group failed to achieve these criteria.

Results. Among the 104 patients, 66 patients (63%) fulfilled the criteria for the effective group within the first year of PEIT. Using the multivariate logistic regression analysis, the number of PTGs before PEIT was a significant risk factor to deviate from the criteria. At the end of the surveillance period, 31 patients (30%) fulfilled the criteria, and their SHPT was controlled with PEIT. Using the multivariate logistic regression analysis, more than three PTGs at the beginning, and the increase in PTGs during the observation period were significant risk factors to deviate from the criteria. In conclusion, superior results with PEIT are obtained in terms of efficacy, remission period and risk of relapse, regardless of the size of the gland.

Clinicopathological analysis of persistent hypercalcemia and hyperparathyroidism after kidney transplantation in long-term dialysis patients

Deceased donor kidney transplantation in long-term dialysis patients in Japan has been increasing because of a severe lack of donors. Parathyroid glands of long-term dialysis patients often show qualitative morphological changes from diffuse to nodular hyperplasia. Only a few studies have reported the clinicopathological analysis of persistent hyperparathyroidism after kidney transplantation in long-term (>10 years) dialysis patients. This study on consecutive deceased donor kidney transplantation performed from 2002 to 2010 measured biochemical parameters related to bone and mineral disorders and examined parathyroid tissues in parathyroidectomy cases. Thirty-four subjects (22 males; mean age, 53.8 ± 7.9 years; mean dialysis period, 14.4 ± 4.3 years) were enrolled. Multivariate analysis of potential predictors for the hypercalcemia group at 12 months after transplantation showed that pre-transplantation and early post-transplantation calcium and parathyroid hormone levels were significant determinants. Pathological examination showed that a number of glands showed nodular hyperplasia, even in small glands weighing < 100 mg. In long-term dialysis patients, hyperparathyroidism and hypercalcemia developed at an early stage after transplantation and persisted for a long period (>4 years), with nodular hyperplasia being found even in low-weight parathyroid glands. Pre-transplant high calcium and parathyroid hormone levels were the predictors for the prolonged hypercalcemia. Persistent hyperparathyroidism was considered to be caused by remaining nodular hyperplasia, even if the glands were small. Although the best treatment option is to perform a parathyroidectomy in the waiting period before transplantation, we suggest that it be performed in cases with prolonged hypercalcemia of >6 months after transplantation.

Use of percutaneous ethanol injection therapy for recurrent secondary hyperparathyroidism after subtotal parathyroidectomy

We evaluated the efficacy of percutaneous ethanol injection therapy (PEIT) as a therapeutic option for recurrence of secondary hyperparathyroidism after subtotal parathyroidectomy in ESRD patients. Six patients underwent PEIT. A mean of 1.3 ± 0.8 ethanol injections was performed. Nodular volume was 1.5 ± 1.7 cm³, and 2.8 ± 2.8 cm³ of ethanol was injected per patient. After ethanol injection PTH decreased significantly (1897 ± 754 to 549 ± 863 pg/mL (P < .01)). There was also a reduction in serum calcium, phosphorus and calcium-phosphorus product. A positive and significant correlation was found between nodular volume with ethanol injected and time from parathyroidectomy. Only one patient required hospitalization due to severe hypocalcaemia. In other two cases, local discomfort and temporary mild dysphonia were registered. PEIT is an effective treatment to control recurrences of secondary hyperparathyroidism postsubtotal parathyroidectomy.

Brown tumour of the spine in a renal transplant patient

We report a 30-year-old male who had undergone a renal transplant and suffered with secondary hyperparathyroidism. He presented with back pain and minimal neurological deterioration, caused by a thoracic brown tumour. The imaging findings, surgical treatment of the spinal lesion and outcome are discussed. We also discuss primary medical therapy and suggest a rational approach to further imaging of patients in whom brown tumour is suspected.

Incidence of parathyroid glands located in thymus in patients with renal hyperparathyroidism

BACKGROUND

Parathyroid glands are frequently located in thymus, and it is essential to resect thymic tissue from the neck incision, especially in surgery for renal hyperparathyroidism (HPT).

METHODS

In this study, we evaluated the incidence, location, and type of intrathymic parathyroid glands in 902 patients who underwent initial parathyroidectomy (PTx) for advanced renal HPT in our department. Removal of the thymic tongues on both sides was routinely performed from the neck incision, and the thymic tissue was carefully examined both macroscopically and microscopically.

RESULTS

Of the 902 patients in the study, 269 had only inferior parathyroid glands in the thymus, in 62 patients only supernumerary glands were found in the thymic tongue, and in 78 patients both inferior and supernumerary glands were present in thymic tissue. Therefore the incidence of patients with intrathymic glands was 45.3% (269 + 62 + 78 = 409/902). In 129 (92.1%) of 140 patients with supernumerary glands in the thymic tongue, these glands were detected only on histopathological examination, and about half of them were classified as the parathyromatosis type.

CONCLUSIONS

In the human, parathyroid glands might be located in the thymus in about 50%. If the inferior gland/glands cannot be found around the inferior pole of thyroid lobe, it is very important to search for glands in the thymic tongue. Moreover, to avoid missing supernumerary glands, removal of the thymic tongue on both sides is essential in surgery for renal HPT.

Ultrasonography for preoperative localization of enlarged parathyroid glands in secondary hyperparathyroidism

OBJECTIVE

Parathyroidectomy (PTx) is sometimes performed to treat secondary hyperparathyroidism (2HPT) related to long-term dialysis. In this procedure, all four parathyroid glands should be resected. However, in patients with 2HPT, the four glands are not uniformly enlarged; therefore, preoperative diagnosis is difficult in comparison with primary hyperparathyroidism. We compared glands detected on preoperative ultrasonography (US) with those resected during PTx to examine the usefulness and limitations of US.

METHODS

The subjects were 44 patients with 2HPT who underwent PTx between December 2003 and November 2007. Surgery was indicated for patients meeting the following three conditions: a serum intact PTH (iPTH) level of 500 pg/ml or more; a maximum glandular volume of 500 mm3 or more; and increased bone metabolism. Before surgery, we detected the parathyroid glands using US, and three-dimensionally measured their sizes. PTx was performed based on US diagnosis, and resected glands were weighed.

RESULTS

Assuming that four parathyroid glands are present in each patient, the total number of glands in the 44 patients was 176. Of the 176 glands, 139 were detected on preoperative US. However, 27 could not be resected. Therefore, the detection rate on US was 63.6% (112/176). Of 37 glands that could not be detected on preoperative US, 30 were detected during surgery, and resected. There was a positive correlation between the glandular volume measured on US and isolated gland weight. However, there was no correlation between the preoperative serum iPTH level and the sum of the four isolated gland weights.

CONCLUSION

On preoperative US, approximately 80% of the glands were detected. However, the misdiagnosis rate was approximately 20%. The rate of accurate diagnosis was 63.6%. Even when glands were misdiagnosed or could not be confirmed on preoperative US, approximately 80% of them could be detected and resected during surgery. It may be impossible to estimate the glandular volume based on the preoperative serum iPTH level.

Percutaneous ethanol injection therapy for advanced renal hyperparathyroidism in Japan: 2004 survey by the Japanese Society for Parathyroid Intervention

Background. Marked hyperplasia of the parathyroid gland (PTG) is a characteristic feature of severe hyperparathyroidism in patients under chronic haemodialysis treatment. Percutaneous ethanol injection therapy (PEIT) is now becoming popular in Japan as a treatment option for secondary hyperparathyroidism (SHPT) and its cost is covered by the National Health Insurance (NHI) System. The Japanese Society for Parathyroid Intervention surveyed its membership in 2004 to revise the guidelines for the use of PEIT.

Methods. The project was approved by the Executive Committee of the Society, and the primary questionnaire was addressed to 3268 centres (departments) affiliated with the Japanese Society for Dialysis Therapy. A follow-up questionnaire was sent to all the centres that responded.

Results. Although the number of centres to which the questionnaire was sent in 2004 was 3268, compared with 2653 in 1998, the number of responses decreased from 1425 (53.7%) in 1998 to 962 (29.4%) in 2004. To the question of whether the centre performed PEIT, 114 (11.9%) answered ‘Yes’ and 848 (88.1%) answered ‘No’ in 2004. It was an increase from 1998 when only 83 (5.8%) of 1425 centres answered ‘Yes’. In the 1998 survey, 612 patients underwent PEIT at 74 centres, and in 2004, 2098 patients underwent PEIT at 111 centres.

Conclusions. PEIT may become the frequently performed treatment for SHPT patients who become resistant to medical therapy. However, the same problems as in 1998 remain unsolved; that is, recurrent nerve paralysis, difficulty of post-PEIT PTx and lack of evidence showing the long-term effectiveness of PEIT.

Recurrent renal hyperparathyroidism caused by parathyromatosis

BACKGROUND

Parathyromatosis is defined as multiple foci of benign hyperfunctioning parathyroid tissue in the neck or mediastinum. Parathyromatosis is a problematic cause of recurrent hyperparathyroidism (HPT). In renal HPT, the stimuli of the parathyroid cells persist after parathyroidectomy (PTx), and for this reason, parathyromatosis might be important in renal HPT.

METHODS

Between July 1973 and December 2005, 1,932 patients underwent PTx for advanced renal HPT in our department. We evaluated the frequency, clinical findings and the prognosis of this kind of parathyroid disorder.

RESULTS

After total PTx with forearm autograft for renal HPT, which was performed initially in our department, the risk for developing parathyromatosis was 0.11% (2/1837); after sub-total PTx, it was 5% (1/20). The risk for developing parathyromatosis was lower after total PTx with forearm autograft than after sub-total PTx (P < 0.05). In patients who developed persistent or recurrent HPT and were referred to our department for neck re-operation, parathyromatosis occurred in 12.1% (7/58); in those originally operated on at our hospital, the corresponding figure was 7.1% (3/42). This difference was not significant (P = 0.42). Only in 4 of 10 patients was parathyromatosis suggested before re-operation. However, in spite of several re-operations, high parathyroid hormone (PTH) levels persisted in 6 of 10 patients with parathyromatosis.

CONCLUSION

Parathyromatosis is a non-negligible cause of recurrent renal HPT in patients who require neck re-exploration. Parathyromatosis is difficult to diagnose pre-operatively and completely controlled by re-operation. Parathyromatosis should be kept in mind when performing neck re-exploration for recurrent renal HPT.

The role of quick bio-intact PTH(1-84) assay during parathyroidectomy for secondary hyperparathyroidism

OBJECTIVE

The role of the quick PTH assay in surgery for secondary HPT is unclear because of overestimation of intact PTH(1-84) values due to the cross-reactivity of currently available first-generation PTH assays with non-PTH(1-84) fragments that accumulate in renal failure. In this study, we used a second-generation quick PTH immunometric assay that are claimed to detect the biologically active PTH(1-84) molecule with no cross-reactivity with PTH fragments to investigate the potential utility of the assay during parathyroidectomy for secondary HPT.

MATERIAL AND METHODS

The study was performed on 18 patients (12 women, 6 men) between October 2004 and March 2005. EDTA serum samples were drawn via a peripheral venous catheter after induction of anesthesia (basal), and at 5, 10, and 30 min after excision of diseased parathyroid glands. Serum active PTH(1-84) was measured by the quick Bio-Intact PTH(1-84) assay, which is a two-site chemiluminometric assay.

RESULTS

At 30 min the quick Bio-PTH(1-84) level of 16 patients was under 45 pg/mL. Four parathyroid glands were removed macroscopically from 12 of the 16 patients, and three glands were removed from the other four patients. All patients were cured of their HPT. Four enlarged parathyroid glands were removed from a patient whose Bio-Intact PTH(1-84) at 30 min had not fallen below 45 pg/mL, and no other glands were found by further exploration. At the 6 mo follow-up examination, the first-generation intact PTH level of this patient was over 45 pg/mL, but several diagnostic imaging methods did not reveal any enlarged parathyroid glands. Three enlarged parathyroid glands from the other patient, and exploration led to the identification of an ectopic parathyroid gland at the carotid bifurcation.

CONCLUSIONS

The results of this prospective study show that quick Bio-Intact PTH(1-84) monitoring is a valuable new tool for use in the surgical treatment of secondary HPT. An intraoperative, quick Bio-Intact PTH(1-84) assay will be of value for the adequate prediction of surgical cure.

Significance of monitoring Bio-Intact PTH (1-84) during parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

The Bio-Intact PTH (1-84) assay has recently been developed to specifically measure the intact PTH (1-84) molecule, and in this study we used it to investigate sequential changes in serum Bio-Intact PTH (1-84) levels during parathyroidectomy for secondary HPT.

MATERIAL AND METHODS

The subjects of this study were 70 patients (41 women, 29 men) who underwent parathyroidectomy between April 2002 and March 2005. Ethylene diamine tetraacetic acid serum samples were drawn via a peripheral venous catheter after induction of anesthesia (basal), and at 5, 10, and 30 min after diseased glands excision. Serum active PTH (1-84) was measured by the Bio-Intact PTH (1-84) assay, which is a two-site chemiluminometric assay.

RESULTS

When 4 or more diseased parathyroid glands were removed, the basal of Bio-Intact PTH (1-84) level in patients without persistent HPT (52 cases) was 539 +/- 355 pg/mL. The level of the Bio-Intact PTH (1-84) at 30 min after sufficient parathyroidectomy had decreased to less than 45 pg/mL, whereas the Bio-Intact PTH (1-84) level in patients with persistent HPT at 30 min was greater than 45 pg/mL (3 cases). After removal of three or fewer diseased parathyroid glands (15 cases), the Bio-Intact PTH (1-84) at 30 min in patients without persistent HPT (13 cases) was less than 45 pg/mL. The 2 patients whose the Bio-Intact PTH (1-84) at 30 min was greater than 45 pg/mL underwent reoperation, and residual enlarged parathyroid gland in the neck was removed.

CONCLUSIONS

The Bio-Intact PTH (1-84) level at 30 min after parathyroidectomy seems to be useful for judging whether the parathyroidectomy is complete irrespective of the number of glands removed from patients with secondary HPT. When only three diseased parathyroid glands are removed, the surgeon can decide whether to continue or stop neck exploration according to the level of Bio-Intact PTH (1-84) at 30 min.

Is the volume of the parathyroid gland a predictor of Maxacalcitol response in advanced secondary hyperparathyroidism?

We evaluated the relationship between the volume of parathyroid glands estimated by ultrasonography (US) and response of 22-oxa calcitriol (Maxacalcitol, OCT) in patients with secondary hyperparathyroidism (2HPT) to evaluate whether the volume can be a predictor of the OCT response. Eleven institutes participated in this study. Ninety-four patients with advanced 2HPT were enrolled. The volume of the parathyroid glands were estimated by US before and 6 months after OCT treatment. The response of OCT treatment was classified into three groups (Group A: i-PTH < 300 pg/mL; Group B: 300 pg/mL < or = i-PTH < 500 pg/mL; Group C: i-PTH > or = 500 pg/mL). Forty-eight patients were in Group A, 28 patients in Group B, and 18 patients in Group C. The PTH levels at the beginning and 6 months were 458.3-199.1 pg/mL (P < 0.0001) in Group A, 524.6-403.2 pg/mL (P = 0.007) in Group B and 736.7-613.6 pg/mL (ns) in Group C, respectively. The volume of the largest gland in Group B was significantly larger than that in Group A (96.2 vs. 343.2 mm3: P < 0.001). Clinical factors affecting response of OCT was evaluated by logistic regression analysis and only the volume of the largest gland was a significant factor. In the patients whose volume was less than 300 mm3, the OCT response was significantly effective. We conclude that the glandular volume of the largest parathyroid gland estimated by US can be a useful factor to predict the OCT response in patients with moderate or severe renal HPT.

Cardiovascular complications caused by advanced secondary hyperparathyroidism in chronic dialysis patients; special focus on dilated cardiomyopathy

BACKGROUND

The frequency and prognosis of dilated cardiomyopathy (DCM) caused by secondary hyperparathyroidism (2 degrees HPT) is not known. The purpose of this study was to determine the morbidity of DCM caused by 2 degrees HPT and the efficacy of parathyroidectomy (PTx) in chronic dialysis patients with advanced 2 degrees HPT was analyzed prospectively.

METHODS

Between November 2000 and January 2003, 237 dialysis patients who underwent total PTx with forearm autograft at our department were enrolled in this study. Cardiac complications that existed before PTx were examined. Ten patients (4%) had DCM without valvular disease (VD) or ischemic heart disease (IHD). In these 10 patients with DCM before operation, we estimated left ventricular (LV) function at 6 months after PTx, according to echocardiography findings and clinical symptoms.

RESULTS

Six months after PTx, left ventricular ejection fraction (LVEF) in these 10 patients was significantly improved, from 31.0 +/- 9.8% before PTx, to 56.8 +/- 13.5% (P = 0.0003), and left ventricular end-diastolic dimension (LVDd) was reduced, from 59.8 +/- 9.7 mm to 46.3 +/- 7.0 mm (P = 0.0014). The symptoms due to DCM and the fall of blood pressure that had occurred during dialysis were clearly improved after PTx.

CONCLUSIONS

Advanced 2 degrees HPT can influence LV function, and in patients who suffered from DCM, LV function was dramatically improved by PTx. PTx should be performed immediately in patients with DCM caused by 2 degrees HPT.

Tratamiento quirúrgico del hiperparatiroidismo secundario recidivado

INTRODUCTION

Secondary renal hyperparathyroidism (SHPT) affects nearly all patients on regular hemodialysis. Between 5% and 10% will need surgery to control the disease. Despite a meticulous technique, the rate of recurrent/persistent hyperparathyroidism after surgery remains between 2% and 12%.

PATIENTS AND METHOD

We reviewed the reoperations of 7 patients with recurrent or persistent SHPT from a series of 56 patients, 3 of which were referred from other units for treatment of recurrence. Subtotal parathyroidectomy (ST-PTX) was performed in 51 patients and total parathyroidectomy with autograft (TPTX-AT) was performed in the remaining 5 patients.

RESULTS

Seven patients underwent reoperation for recurrent SHPT, 1 of them twice (8 reinterventions in 56 patients). In 2 patients only 3 parathyroid glands were removed at the first intervention and recurrence was due to the presence of a fourth gland. In 4 patients, ST-PTX was performed and recurrence was due to a remnant hyperplasic area in 1 and to a fifth gland in 3. Recurrence in the patient with a TPTX-AT was to due to cervical parathyromatosis. All the patients with recurrence had a positive preoperative Tc-MIBI scintigraphy and the computed tomography/magnetic resonance examination was highly useful for anatomical localization of the lesion and for planning the surgical approach.

Surgical Indications and Procedures of Parathyroidectomy in Patients with Chronic Kidney Disease

The Kidney Foundation of the USA proposed clinical practice guidelines for bone metabolism and disease in chronic kidney disease including parathyroidectomy (PTx). We performed PTx in a total of 1725 patients with advanced secondary hyperparathyroidism (2HPT) and evaluated the K/DOQI guideline concerning PTx, comparing it with our surgical strategy. The guidelines emphasize the avoidance of ectopic calcification and cardiovascular complications which may be induced by hypercalcemia, hyperphosphatemia, and persistent high parathyroid hormone level. We agree with the attitude of the K/DOQI guideline. To decide surgical indications, we emphasize that the size of parathyroid gland is one of the important factors. The guideline recommends subtotal PTx and total PTx with autotransplantation. We prefer total PTx with forearm autograft, mainly because it is easier and safer to remove the residual parathyroid tissue from the forearm at recurrence compared to neck re-exploration. In Japan, almost all patients require long-term hemodialysis after PTx because of the very small opportunity of kidney transplantation. The risk of recurrence is not negligible. Based on our huge experience we believe our strategy for advanced secondary hyperparathyroidism can be accepted at least in Japan.

Re-operation for hyperparathyroidism

INTRODUCTION

Re-operation for hyperparathyroidism (HPT) represents a challenge for experienced endocrine surgeons. The present study reviews the technical and pathological factors for failure of initial surgery and identifies strategies to approach re-operative parathyroidectomy.

METHODS

Clinical details, operation notes, pathology, localization studies and complications for re-operative cases performed by three surgeons were reviewed.

RESULTS

Over a 10-year period there were 40 re-operative cases with a 98% success rate. There were 31 patients with primary HPT, 21 with persistent primary (PP) and 10 with recurrent primary (RP). Multigland disease (MGD) was present in 19 of the 31 (61%) primary HPT cases. The culprit gland was ectopic in 14 cases, at a normal location in 10 and there was regrowth at previously excised sites or remnant disease in 10. There were nine patients with secondary HPT, four with persistent secondary (PS) and five with recurrent secondary (RS). The culprit gland was ectopic in five, at a normal location in four and regrowth at a previously excised site in two. Pre-operative investigations were employed in all cases and the most helpful were sestamibi scan (S) and selective venous sampling (SVS) for parathyroid hormone (PTH) concentration. True positive localizations for S was in 20 of 34 cases (59%), SVS in seven of nine (78%), computed tomography (CT) in seven of 17 (41%) and ultrasound scan (USS) in 10 of 28 (36%).

CONCLUSIONS

Re-operative parathyroidectomy can be performed by experienced surgeons with a very high success rate and minimal complications.

More than 1,000 cases of total parathyroidectomy with forearm autograft for renal hyperparathyroidism

Between March 1981 and December 2000, we performed 1,053 total parathyroidectomies with forearm autograft for advanced renal hyperparathyroidism (HPT). Based on histopathologic and pathophysiologic investigations, surgical treatment should be considered when parathyroid glands show nodular hyperplasia. Measuring parathyroid volume by ultrasonography was useful to detect nodular glands and to determine surgical indications. The clinical effect of parathyroidectomy on the symptoms and biochemical variables was striking. Skeletal deformity, progressive bone loss, and vessel calcification leading to high mortality risk could not be alleviated by even successful surgery, however. To prevent cardiovascular complications, parathyroidectomy should be performed in the relatively early stage of renal HPT. Total parathyroidectomy with forearm autograft is a suitable procedure for renal HPT, especially in patients who require long-term hemodialysis. For surgeons, it is important to remove all parathyroid glands, including supernumerary glands, at the initial operation and to choose adequate parathyroid tissue for the autograft to prevent persistent and recurrent HPT. Although the risk of graft-dependent recurrent HPT is not negligible, enlarged transplanted parathyroid tissue can be removed easily and noninvasively from the forearm under local anesthesia. There is no risk of hypofunction of the autograft.