When is surgery indicated in hyperparathyroidism?

Surgical Indications for Hyperparathyroidism

Surgery is indicated for hyperparathyroidism in cases of severe disease with persistent PTH levels >800 pg/mL accompanied by hypercalcemia and/or hyperphosphatemia that are refractory to medical therapy. 1

Secondary Hyperparathyroidism (CKD-related)

Surgical parathyroidectomy should be considered when:

• Severe hyperparathyroidism (persistent serum intact PTH >800 pg/mL) occurs with hypercalcemia and/or hyperphosphatemia that does not respond to medical therapy 1
• Calciphylaxis is present with elevated PTH levels (>500 pg/mL), as clinical improvement has been documented after surgical intervention 1
• Medical therapy fails to control the hyperparathyroidism despite optimal management with dietary phosphate restriction, phosphate binders, and vitamin D sterols 1

Primary Hyperparathyroidism

Parathyroidectomy is indicated for:

• Symptomatic PHPT with manifestations such as bone pain, fractures, nephrolithiasis, and muscle weakness 2
• Asymptomatic PHPT with any of the following criteria:
  • Osteoporosis or vertebral fractures 2
  • Age <50 years 2
  • Serum calcium >1.0 mg/dL above upper limit of normal 2
  • Creatinine clearance ≤60 mL/min 2
  • Nephrolithiasis or nephrocalcinosis 2
  • Hypercalciuria 2

Hyperparathyroidism in Renal Transplant Recipients

Surgical intervention should be considered when:

• Persistent hypercalcemia occurs post-transplant (particularly if serum calcium is ≥11.5 mg/dL) 1
• Calciphylaxis develops 1
• Rapidly worsening vascular calcification is present 1
• Symptomatic hyperparathyroid bone disease develops 1
• Spontaneous fractures occur in the presence of hyperparathyroidism 1

Predictors of Recurrent Hyperparathyroidism

Patients with the following factors may need more aggressive surgical approaches:

• Preoperative hypercalcemia 3
• Calcinosis/calciphylaxis 3
• Elevated post-operative PTH levels (post-operative PTH <10 pmol/L has a positive predictive value of 97.5% for cure) 3

Surgical Approaches

• Both subtotal parathyroidectomy and total parathyroidectomy with parathyroid tissue autotransplantation are effective surgical options 1
• The choice of procedure may be at the surgeon's discretion as no one technique has proven superior outcomes 1
• Total parathyroidectomy without autotransplantation is generally not recommended for patients who may subsequently receive a kidney transplant, as controlling serum calcium levels post-transplant may be problematic 1

Pre-operative Imaging

• Routine preoperative imaging is not necessary for initial parathyroid surgery 1
• Imaging with 99Tc-Sestamibi scan, ultrasound, CT scan, or MRI should be performed prior to re-exploration parathyroid surgery 1
• Of the available methods, 99Tc-sestamibi with or without subtraction techniques appears to have the highest sensitivity 1

Post-operative Management

• Monitor ionized calcium every 4-6 hours for the first 48-72 hours after surgery, then twice daily until stable 1
• Initiate calcium gluconate infusion if ionized calcium falls below normal (<0.9 mmol/L) 1
• When oral intake is possible, administer calcium carbonate 1-2g three times daily and calcitriol up to 2g/day 1
• Adjust or discontinue pre-surgery phosphate binders based on serum phosphorus levels 1

Important Caveats

• The indications for surgical parathyroidectomy are not well defined, and there are no absolute biochemical criteria that predict when medical therapy will fail 1
• Parathyroidectomy should not be performed in patients with calciphylaxis who do not have documented hyperparathyroidism 1
• Patients with large parathyroid mass might fail medical therapy, but there is insufficient evidence to support using parathyroid mass assessment to predict medical therapy efficacy 1
• For renal transplant candidates, some experts recommend waiting at least 1 year post-transplant to allow for possible spontaneous regression of hyperparathyroidism before considering surgery 1