Treatment Approach for Primary Hyperparathyroidism (PHPT)
Surgical parathyroidectomy is the only curative treatment for primary hyperparathyroidism and should be recommended for all symptomatic patients and those meeting specific criteria for asymptomatic disease. 1
Diagnosis and Initial Assessment
- Primary hyperparathyroidism is defined by hypercalcemia with elevated or inappropriately normal PTH levels
- Most cases (80%) are caused by a single parathyroid adenoma, with the remainder due to multiple adenomas, hyperplasia, or rarely carcinoma (<1%) 1
- Modern presentation in developed countries is often asymptomatic, detected through routine biochemical screening
Indications for Surgery
Surgery is indicated for:
All symptomatic patients with:
- Bone manifestations (osteoporosis, fractures)
- Kidney stones or nephrocalcinosis
- Neurocognitive disorders
- Muscle weakness
Asymptomatic patients meeting any of these criteria:
- Serum calcium >0.25 mmol/L above upper limit of normal
- Age <50 years
- Osteoporosis (T-score ≤-2.5 at any site)
- Impaired kidney function (GFR <60 mL/min/1.73m²)
- Kidney stones or nephrocalcinosis
- Hypercalciuria 1
Surgical Approaches
Two effective surgical approaches exist:
Bilateral Neck Exploration (BNE):
- Traditional approach where all four parathyroid glands are identified
- Required when preoperative imaging is discordant/nonlocalizing or MGD is suspected
- Higher complication rates but necessary in complex cases
Minimally Invasive Parathyroidectomy (MIP):
- Targeted unilateral approach with limited dissection
- Requires confident preoperative localization of a single adenoma
- Benefits: shorter operating times, faster recovery, decreased costs 1
- Intraoperative PTH monitoring confirms removal of hyperfunctioning gland
Preoperative Imaging
- Imaging is essential for surgical planning but has no role in diagnosis 1
- First-line imaging options:
- 99Tc-sestamibi scan (highest sensitivity)
- Ultrasound
- CT scan
- MRI
- Imaging is particularly crucial for reoperative cases 1
Post-Surgical Management
After parathyroidectomy:
- Monitor ionized calcium every 4-6 hours for first 48-72 hours, then twice daily until stable 1
- If calcium drops below normal (<0.9 mmol/L), initiate calcium gluconate infusion at 1-2 mg elemental calcium/kg/hour 1
- When oral intake is possible, provide calcium carbonate 1-2g three times daily plus calcitriol up to 2μg/day 1
- Adjust phosphate binders based on serum phosphorus levels 1
Medical Management Options
For patients who cannot undergo surgery:
- Bisphosphonates: improve bone mineral density but don't normalize calcium
- Calcimimetics (cinacalcet): reduce calcium levels but don't improve bone density
- Combination therapy may be needed for optimal management
- No medical therapy is curative 2, 3
Special Considerations
- Daycare surgery is feasible and safe for selected patients, though post-operative calcium supplementation is recommended to reduce emergency department visits 4
- Mild PHPT (subtle biochemical abnormalities) may still benefit from surgery as evidence suggests improvement in symptoms and prevention of disease progression 5
- Tertiary hyperparathyroidism (persistent hypercalcemic hyperparathyroidism) may require parathyroidectomy if resistant to medical therapy 1
Pitfalls to Avoid
- Don't rely on imaging to diagnose PHPT; diagnosis is biochemical (elevated calcium with elevated/inappropriately normal PTH)
- Don't perform total parathyroidectomy without autotransplantation in patients who may receive kidney transplants, as calcium management becomes problematic 1
- Don't delay surgery in symptomatic patients as medical therapy is not curative
- Ensure appropriate PTH assay interpretation using assay-specific reference ranges 1
The definitive treatment for PHPT remains surgical excision of the abnormal parathyroid tissue, with the specific approach determined by preoperative localization studies and surgical expertise.