Parathyroidectomy

Both sides of the thyroid are explored, and all 4 parathyroid glands are identified.

Based on appearance (size, color, firmness) and/or intra-operative pathology analysis (aka ‘frozen biopsy’, a piece of the parathyroid gland is given to a pathologist to under microscope during the surgery), the bad gland(s) are removed.

Recommended for:

• Non-localizing (adenoma not found) or discordant (findings different on ultrasound compared to Sestamibi / 4D CT) imaging.
• High suspicion for multi-gland disease.
  • Based on imaging findings.
  • Normocalcemic variant pHPT.
  • History of long-term Lithium use.
  • MEN syndrome.
  • Kidney related hyperparathyroidism.
  • Intraoperative PTH monitoring not available (read more in the Minimally Invasive Parathyroidectomy section in the column on the left).

Disadvantages:

• Surgeries can be longer.
• Increased post-operative discomfort and longer recovery.
  • More dissection and manipulation of tissues causes increased inflammation, swelling, and pain.
• Increased risk for hypoparathyroidism (both temporary and permanent – see below) due to manipulating all 4 glands.
• Introduces risk for possible bilateral recurrent laryngeal nerve injury.
  • Can result in respiratory distress (life-threatening breathing difficulty) requiring a tracheotomy tube in the neck to breathe (temporary or permanent).

Can be performed on its own, or in conjunction with intraoperative PTH monitoring (read more in the Minimally Invasive Parathyroidectomy section in the column on the left).

• Higher cure rates when performed with intraoperative PTH monitoring.

Same location of the incision is used, can be slightly smaller (2-3 cm or 1 inch).

Focused one-sided exploration.

• 85% of pHPT is caused by a single parathyroid adenoma.
• Recommended for:
  • Imaging suggesting a single parathyroid adenoma, especially with co-localizing studies (ultrasound and Sestamibi / 4D CT scan showing the same findings).
  • No history to suggest increased risk for multi-gland disease.

Advantages:

• Surgery can be faster.
• Smaller incision.
• Less discomfort and quicker recovery.
  • Less dissection and tissue manipulation.
• Reduces risk for hypoparathyroidism (no manipulation of the other 3 parathyroid glands).
• Removes the risk of bilateral recurrent laryngeal nerve injury and need for a tracheotomy tube.

Must be used in conjunction with intraoperative PTH monitoring.

• Rules out the presence of other hyperfunctioning parathyroid glands (double adenoma – 10% risk or 4 gland hyperplasia – 5% risk) without having to search for them.
  • Can ensure cure before ending the surgery.
• Takes advantage of short half-life of PTH in the blood (rapidly metabolized / removed by the kidneys and liver).
• Baseline PTH obtained on day of surgery.
• PTH levels are then measured 5, 10, and 15 min after the parathyroid adenoma is removed (but still while the patient is asleep in the operating room) and compared to the baseline level.
  • Patient is considered cured if:
    • PTH levels drop by > 50% of baseline.
    • Into the normal range (~15–85 pg/ml, varies by lab test).
    • Demonstrates a pattern of decline (continued decrease in value, no plateau or rise).
  • If patient is not considered cured by these criteria, conversion to a 4-gland exploration should be performed to identify and assess the 3 remaining glands.

Intraoperative PTH monitoring can be affected by:

• Manipulation of the adenoma prior to removal.
  • PTH levels falsely elevated by squeezing the gland prior to removal, thus taking longer for the PTH levels to drop into the desired range.
• Slow metabolizers of PTH (elderly patients, patients with kidney or liver disease, obese patients) take longer for PTH levels to drop.

For MIP, imaging directs you where to start the surgery, PTH levels during the surgery inform you when to stop.

With improved pre-operative imaging and widespread availability of intraoperative PTH monitoring, MIP is now widely performed and the most common parathyroid surgery performed.

Prior to surgery, the normal parathyroid glands’ ‘teeter-totter’ function was working appropriately.

• With high calcium levels they were producing little to no PTH.

As the calcium levels slowly fall back to normal range following surgery, the remaining parathyroid glands will resume their normal function.

• Risk for temporary hypoparathyroidism (low PTH levels) resulting in hypocalcemia (low calcium levels).
  • Remaining parathyroid glands are sluggish to wake up following a long time of being inactive.
    • Increased risk with:
      • Double adenomas – two glands were removed, now only two glands remain.
      • Extreme hypercalcemia (>12.0) prior to surgery – more likely to have been completely inactive and can take longer to wake up.
      • Underlying Secondary Hyperparathyroidism (sHPT):
        • Vit D deficiency, kidney disease, malabsorption, history of gastric bypass surgery, etc.
  • The remaining parathyroid glands’ function were temporarily compromised as the result of manipulation during the surgery.
  • Increased risk with 4-gland exploration and frozen biopsy interpretation.
  • Low calcium levels manifest clinically with numbness and tingling in the lips or fingertips in early stages or cramping in the hands or feet in later stages.
  • Treated with temporary over the counter calcium supplements.
    • For patients with history of gastric bypass, calcium citrate should be used instead of more commonly available calcium carbonate.

Occurs only in 5 % of pHPT.

The body needs some functioning parathyroid tissue to keep calcium levels in the normal range.

• Removing all 4 glands would result in permanently low PTH levels (hypoparathyroidism) and as a direct result permanently low calcium levels (hypocalcemia).
• This would require daily calcium and Vit D supplementation, 2-3 times per day for the rest of the patient’s life.

Instead, 3 and ½ of the glands are removed (sub-total resection).

• Leaving half of the most normal appearing gland (referred to as the remnant gland) with the best retained blood supply to ensure continued function.
• Intraoperative PTH levels can still be used to ensure no rare 5th gland (~1% chance) or too large of a remnant gland being left behind.

~1% of risk of permanent hypoparathyroidism / hypocalcemia.

• ½ remaining (remnant) gland is not large enough or its blood supply was compromised and it did not survive.

Confirmed with calcium and PTH levels returning to normal ranges and lasting for 6 months following surgery.

• If calcium returns to normal, but PTH levels remain elevated:
  • Indicates cure of pHPT (success of surgery) but reveals underlying secondary hyperparathyroidism (sHPT).
    • Usually caused by Vit D deficiency, kidney disease, malabsorption, gastric bypass surgery, etc.
    • Important to identify this prior to surgery and correct if possible.

There is a ~ 1% chance that one of the remaining parathyroid glands can turn into a parathyroid adenoma in the future and cause a recurrence of pHPT.

• Recurrence is routinely screened for with standard blood work (basic metabolic panel or complete metabolic panel, both of which includes measuring Calcium levels) obtained during yearly physicals or follow-ups with your PCP.

Surgical outcomes / cure rates are the highest and complication rates are the lowest when surgery is performed by a high-volume surgeon (> 50 parathyroidectomy surgeries per year).

To read more about the Parathyroidectomy surgery including what to expect, as well as details regarding recovery and risks see Parathyroidectomy.