PRIMARY HYPERPARATHYROIDISM

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1 PRIMARY HYPERPARATHYROIDISM

2 HYPERPARATHYROIDISM Inappropriate excess secretion of Parathyroid Hormone in Primary Hyperparathyroidism Appropriate Hypersecretion in Secondary Hyperparathyroidism

3 PTH and CALCIUM HOMEOSTASIS + PTH CALCIUM -

4 PTH and CALCIUM HOMEOSTASIS c-pth Vit D3 PTH _ n-pth Phos Ca ++ (Albumin) Renal c-amp Bone Osteoclast GI Absorption GI, Renal : 1,25 D Calcitonin (?) + CALCIUM

5 Epic Review at Cleveland Clinic 0.86% population prevalence Majority not diagnosed or treated

6 The Steps 1) Diagnosis 2) Reason to operate? 3) How to operate

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9 NormoCalcemic Primary Hyperparathyroidism Recognized in 2009 Guidelines Elevated PTH + normal Ca Frequently encountered in those being managed for osteoporosis Must exclude all causes of 2º hpth Renal failure, low Ca diet, hypo D, bariatric, celiac, loop diuretics

10 NormoHormonal Primary Hyperparathyroidism Inappropriately Normal PTH levels with a high serum Ca 10-20% of hpth have upper end normal minimally elevated PTH PTH pg/ml (10-60) Consider FHH

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12 Role of 24 hour urine 40% of phpth hypercalciuric Not usually needed to make diagnosis In patients with borderline labs helps distinguish FHH, or primary renal dz

13 There is no parathyroid imaging in this algorithm

14 The Steps 1) Diagnosis 2) Reason to operate? 3) How to operate

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16 Surgical Referral? Symptomatic hyperca Nephrolithiasis Osteitis fibrosis cystica Bone pain, subperiosteal reabsorption, salt and pepper skull, bone cysts, brown tumors Non-specific neuropsychiatric symptoms alone are not symptomatic disease and not a clear surgical indication.

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18 In some patients with asymptomatic disease, surgery is not mandatory. On the other hand, even in these subjects who don t meet any criteria for parathyroidectomy, surgery is always an option because it is the only definitive therapy for PHPT. Bilezikian et al, 2014

19 The Steps 1) Diagnosis 2) Reason to operate? 3) How to operate

20 Pathology 89% Solitary Adenoma 5% Double Adenoma 6% Four Gland Hyperplasia <<1% Parathyroid Cancer

21 The most important preoperative localization challenge in PHPT is to locate the parathyroid surgeon John Doppman, 1975 Endocrine Radiology, NIH

22 Parathyroidectomy Routine four gland exploration Minimally Invasive Parathyroidectomy Both are accepted standards of care

23 Parathyroidectomy Components of MIP Pre-operative imaging localization Targeted Exploration iopth monitoring

24 200 consecutive patients undergoing surgeon performed clinic ultrasound 72% clearly localizing U/S 96.2% with surgical findings concordant with U/S All experienced surgical cure

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26 Non-localizing u/s If non-localizing, inconclusive localizing, or re-operative, proceed to CT

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29 4DCT = dynamic contrast enhancement over time One contrast bolus and four CT scans in original protocol

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31 After 2000 Increasingly mild biochemical signature, including normocalcemic primary hyperparathyroidism. Now Increasing number of patients with unclear presence of a true disease state and low biochemical profile

32 Two scans/phases equivalent to four Radiation dose same as sestamibi

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34 Parathyroidectomy Surgical Results? Medical Results?

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36 Parathyroidectomy Complications Failure to cure (1-4%) Laryngeal nerve injury (<1%) Hypoparathyroidism (<1%) Hematoma with airway compromise (<<1%)

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39 Fracture Risk Multiple observational studies No RCT of PTX vs no surgery No trials comparing PTX with bisphosphonates in phpth

40 Untreated ~ 1/3 will develop stones Treated ~ 1/10 will develop stones

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42 Cardiovascular Possible long-term survival benefit Benefit becomes apparent 15 years following parathyroidectomy Possible improvement in HTN Ultimately, evidence inconclusive

43 Cinacalcet (Sensipar) in Primary hpth Calcimimetic at the CaSR Normalizes Ca in 75% <10% decrease in PTH No known benefit to BMD or nephrolithiasis, ultimately higher cost than parathyroidectomy.

44 SECONDARY HYPERPARATHYROIDISM Disorders of Vit. D Metabolism Disorders of Phosphorus Metabolism Disorders of Calcium Metabolism Chronic Renal Failure

45 PTH Levels in Secondary Hyperparathyroidism The majority of dialysis patients have some elevation in PTH. A level in the pg/ml range is common. Elevated level alone is not an indication for surgical Rx.

46 Effects of Renal Failure on PTH Homeostasis Diminished renal hydroxylation of D3 Decreased GI absorption of Calcium Decreased suppression of PTH by D3 Decreased (total) serum Calcium Decreased renal excretion of phosphorus Direct effect of Hyperphosphatemia Decreased ionized Calcium Elevated set point of PTH responsiveness Osteoblast resistance to PTH Autonomous Hypersecretion from Hyperplasia

47 Medical Treatment/Prophylaxis of Secondary HyperPTH Calcitriol supplement (Rocaltrol or Calcigex) Limit Phosphorus intake Calcium Supplementation GI Phosphate Binders Calcium Carbonate (Tums) Calcium Acetate (PhosLo) Exchange resin (Renagel) Avoid Aluminum-containing antacids Vit D3 Calcitriol Synthetic analog (Zemplar) Monitor Phos, Ca, PTH, Al, Bone density SENSIPAR Consider Surgical Rx

48 SECONDARY HYPERPARATHYROIDISM INDICATIONS for SURGICAL Rx Failure of maximal medical Rx Ca x PO4 product (55 70) Progressive decrease in bone density Symptoms with significant disability Calcinosis Cutis. Special circumstance Tertiary?

49 SECONDARY HYPERPARATHYROIDISM Surgical Options Subtotal Parathyroidectomy or Total Parathyroidectomy with PTH Autotransplant Essential Components of Either Procedure: Complete Neck Exploration Identification of All PTH s Ablation of Hyperplastic Glands Leave mg Functioning PTH Consider temporary central line

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51 Total Parathyroidectomy With Autotransplant

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53 Subtotal Parathyroidectomy

54 Hypercellular Parathyroid 800 mg

55 Subtotal PTH-x vs Total PTH-x with AutoTx Long term Recurrence of Secondary Hyper PTH Complexity and Duration of Surgery Ease / Cost of Post-op Care Patient Compliance Calcinosis special situation

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57 SECONDARY HYPERPARATHYROIDISM Post-op Care Neck Exploration Precautions Calcium monitoring Calcium Supplement, IV vs PO Discharge Criteria Duration of Calcium Supplementation

58 Questions?

59 SECONDARY HYPERPARATHYROIDISM Surgical Rx - Summary Biochemical Dx Surgery Pitfalls in Pre-op Evaluation Choice of Surgical Procedures Intra-op Rapid PTH Assay Post-op Primary HyperPTH Results