Secondary and tertiary hyperparathyroidism, state of the art surgical management

Secondary hyperparathyroidism: Uncommon cause of a leg ulcer

INTRODUCTION

Most leg ulcers are vascular based. Only if vascular therapy fails other causes are considered. We report the case of a female with incapacitating leg ulcers caused by a rare condition which was only diagnosed after failing treatment.

PRESENTATION OF CASE

The female had an extensive previous history including diabetes, renal insufficiency and cardiovascular disease and presented with three large and painful ulcers on her left lower leg. Standard treatment with antibiotics, wound excision and additional treatment with hyperbaric oxygen were ineffective. One month post hospital-admission calciphylaxis cutis caused by renal failure induced secondary hyperparathyroidism was diagnosed. Surgical treatment by a parathyroidectomy induced rapid regeneration of the ulcers.

DISCUSSION

Our patient's vast comorbidity and previous history had expanded differential considerations causing a delay in diagnosis. Our patient's previous history led us to believe her ulcers were vascular based, however her chronic renal failure appeared responsible for her condition.

CONCLUSION

Although less probable than venous insufficiency and concomittant leg ulcers or other differential considerations, calciphylaxis cutis should be part of the differential diagnosis in any end stage renal disease-patient with unexplained ulcers as an effective therapy is readily available.

The surgical management of renal hyperparathyroidism

Secondary and tertiary hyperparathyroidism (HPT) develop in patients with renal failure due to a variety of mechanisms including increased phosphorus and fibroblast growth factor 23 (FGF23), and decreased calcium and 1,25-dihydroxy vitamin D levels. Patients present with various bone disorders, cardiovascular disease, and typical laboratory abnormalities. Medical treatment consists of controlling hyperphosphatemia, vitamin D/analog and calcium administration, and calcimimetic agents. Improved medical therapies have led to a decrease in the use of parathyroidectomy (PTX). The surgical indications include parathyroid hormone (PTH) levels >800 pg/ml associated with hypercalcemia and/or hyperphosphatemia despite medical therapy. Other indications include calciphylaxis, fractures, bone pain or pruritis. Transplant recipients often show decreased PTH, calcium and phosphorus levels, but some will have persistent HPT. Evidence suggests that PTX may cause deterioration in renal graft function in the short-term calling into the question the indications for PTX in these patients. Pre-operative imaging is only occasionally helpful except in re-operative PTX. Operative approaches include subtotal PTX, total PTX with or without autotransplantation, and possible thymectomy. Each approach has its proponents, advantages and disadvantages which are discussed. Intraoperative PTH monitoring has a high positive predictive value of cure but a poor negative predictive value and therefore is of limited utility. Hypocalcemia is the most common complication requiring aggressive calcium administration. Benefits of surgery may include improved survival, bone mineral density and alleviation of symptoms.

Surgical parathyroidectomy versus cinacalcet therapy: in the management of secondary hyperparathyroidism

OBJECTIVES

The aim of this study was to compare the clinical effectiveness of surgery with calcimimetics as treatment strategies for managing the biochemical abnormalities that characterize secondary hyperparathyroidism (2HPTH), resistant to optimal conventional therapy in patients with end-stage renal failure (ESRF).

STUDY DESIGN

A historical cohort study.

SETTING

Maxillofacial Department, Morriston Hospital, Swansea, United Kingdom.

SUBJECTS AND METHODS

Fifty-four patients with 2HPTH resistant to optimal conventional medical management were studied. One cohort of 20 patients was treated with surgical parathyroidectomy, the other cohort of 34 patients with cinacalcet. Serum parathyroid hormone (PTH) and bone profile were measured before and at monthly intervals after intervention.

RESULTS

Both cohorts were comparable in their demographic profile, pretreatment comorbidities, baseline PTH, and bone profile. In all 20 surgical patients, the 1-week postoperative PTH had decreased by 97% (P < .001); in the medical cohort after 4 months of daily cinacalcet, the PTH decreased by 48% (P < .001) from baseline. This reduction was maintained at 18 months. In all but 1 surgical patient, alkaline phosphatase (ALP) decreased to normal levels, whereas on cinacalcet, there was no statistically significant reduction. Patients who underwent parathyroidectomy had a more significant decrease in PTH (P < .001) and ALP (P < .0014) than did patients on cinacalcet therapy. All patients managed surgically who complained of preoperative symptoms of pruritis and bone pain expressed complete resolution or significant improvement after parathyroidectomy (P < .001, P < .003, respectively).

CONCLUSION

Surgery was superior to "medical" parathyroidectomy in controlling PTH and ALP.

Life-Threatening Hypocalcemia following Subtotal Parathyroidectomy in a Patient with Renal Failure and Previous Roux-en-Y Gastric Bypass Surgery

Background. Roux-en-Y gastric bypass (RYGB) can result in calcium and vitamin D deficiency. Parathyroid surgery carries the risk of immediate and long-term hypocalcemia. Methods and Results. We describe a 54-year-old woman with history of end-stage renal disease and gastric bypass surgery who developed calciphylaxis requiring a 3.5-gland parathyroidectomy. Seven weeks later, she presented with weakness, perioral numbness, leg cramps, a positive Chvostek's sign, hypotension, prolonged QT-interval, and serum calcium of 5.4 mg/dL. Oral and intravenous calcium, calcitriol, and high calcium bath hemodialysis were given. She required 18 days of intravenous calcium and an outpatient maintenance regimen of calcitriol 6 mcg/day, calcium carbonate 8 grams/day, calcium citrate 1.2 grams/day, and ergocalciferol 50,000 IU/week. Conclusion. The patient's life-threatening prolonged hypocalcemia and large requirements of calcium and calcitriol were due to a combination of malabsorption, hypoparathyroidism, and renal failure. Special considerations should be given to bariatric surgery patients undergoing neck exploration.

[Parathyroid dysfunction and rheumatic manifestations]

Parathyroid dysfunction, leading to severe clinical symptoms and radiographic changes, has decreased over the last years due to routine laboratory checks including serum calcium levels. Thus, abnormal calcium levels are detected early in the course of the disease and the underlying cause treated accordingly. Hyperparathyroidism often leads to osteoporosis and low-trauma fractures. When evaluating secondary osteoporosis analysis of calcium, phosphate and intact parathyroid hormone levels are mandatory. Osteitis fibrosa cystica and brown tumors are less frequent findings of hyperparathyroidism. However, in patients with arthritis or bone symptoms, hyperparathyroidism has to be evaluated as a possible reason. Other manifestations of hyperparathyroidism include myopathy, tendon ruptures and unspecific symptoms of the muscles and skeleton. Gout as well as pseudogout may be associated with hyperparathyroidism. Hypoparathyroidism may cause musculoskeletal diseases mimicking ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis. Myopathies are sometimes induced by hypoparathyroidism. An association between systemic lupus erythematosus and hypoparathyroidism seems to exist.

Intraoperative adjuncts for parathyroid surgery

In recent years, parathyroid surgery has evolved from traditional bilateral neck exploration to minimal invasive parathyroidectomy. This trend became possible due to preoperative localization imaging that guides the surgeon in the search for a parathyroid adenoma. Intraoperative adjuncts are complementary to preoperative localization and assist in localizing parathyroid glands, confirming parathyroid tissue and establishing a cure. Institutions and surgeons utilize different intraoperative adjuncts in different protocols with varying results. The purpose of this article is to review the available intraoperative adjuncts to parathyroid surgery and critically evaluate their utility, accuracy and their added value to the surgeon.

Surgical treatment of tertiary hyperparathyroidism after renal transplantation: a 31-year experience in a single institution

Tertiary hyperparathyroidism (tHPT) most commonly refers to a persistent secondary hyperparathyroidism even after successful renal transplantation. Parathyroidectomy (PTX) is an efficient method for treatment of tHPT. In this study, we examined our 31-year experience with patients who underwent PTX for tHPT after KTX and assessed the effects of PTX on graft function according to the type of surgery. Among 2,981 recipients who underwent renal allograft between April 1979 and Dec. 2010, 15 patients (0.5%) were identified as having tHPT and underwent PTX. Levels of intact parathyroid hormone (iPTH) and serum calcium were measured before and after PTX for evaluation of the therapeutic effect, and glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) equation for investigation of any effect on graft function. One patient showed persistent hyperparathyroidism and hypercalcemia after limited PTX. We experienced 14 successful PTXs, including 3 total PTX with autotransplantations, 8 subtotal PTXs, and 3 limited PTXs. Level of iPTH and serum calcium were at normal range after PTX. Estimated GFR decreased after PTX. Total PTX with autotransplantation showed a tendency of more decrease in the values of iPTH, and GFR after PTX than Subtotal PTX. PTX can cure tHPT-specific symptoms and signs by recovery of hypercalcemia, but may carry the risk of deterioration of kidney graft function. We suspect that subtotal PTX, rather than total PTX with AT, prevent any risk of kidney graft deterioration in surgical treatment of tHPT, and, in selective tHPT patients, limited PTX might be recommended.

Clinical utility of calcimimetics targeting the extracellular calcium-sensing receptor (CaSR)

Calcimimetics, which activate the extracellular calcium (Ca(o)(2+))-sensing receptor in the parathyroid and other tissues participating in Ca(o)(2+) homeostasis, were the first described allosteric activators of a G-protein-coupled receptor. Cinacalcet, the only calcimimetic currently approved for human use, is used clinically for treating secondary hyperparathyroidism (e.g., overactivity of parathyroid glands) in patients being dialyzed for chronic kidney disease. By sensitizing the parathyroids to Ca(o)(2+), cinacalcet lowers the circulating parathyroid hormone (PTH) level. It also reduces serum calcium and phosphate, changes increasing the percentage of patients achieving the guidelines recommended by the National Kidney Foundation (NKF) for these minerals. Studies are underway addressing whether better adherence to these guidelines in patients receiving cinacalcet reduces cardiovascular disease and related mortality, which are both common is the dialysis population. The second approved use of cinacalcet is for treating hypercalcemia in patients with inoperable parathyroid carcinoma. In this setting, it provides the first medical therapy chronically lowering serum calcium concentration in this condition, albeit not to normal in most patients. Its effect on the long-term prognosis of these patients, if any, is presently unclear. "Off-label" administration of cinacalcet [i.e., not yet approved by the US Food and Drug Administration (FDA)] effectively lowers serum calcium and/or PTH in various other forms of hyperparathyroidism and increases serum phosphate in renal phosphate-wasting syndromes by reducing PTH-induced phosphaturia. In the future, the drug could conceivably be utilized to modulate the activity of the CaSR in other tissues (i.e., kidney, colon) in therapeutically desirable ways.