http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/endocrinology/hypercalcemia/
Indications for Treatment.
Removal of the abnormal and hyperfunctioning parathyroid tissue results in a long-term cure of HPT in 96% of patients and significant improvement in associated symptoms. The following criteria were proposed as indications for parathyroidectomy based on a National Institutes of Health–sponsored panel and endocrine specialty societies: 7
- Serum Ca level more than 1 mg/dL above the upper limit of normal
- Marked hypercalciuria higher than 400 mg/day
- Creatinine clearance reduced more than 30% compared with age-matched controls
- Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius of more than 2.5 standard deviations below peak bone mass (T score lower than -2.5)
- Age younger than 50 years
- Patients for whom medical surveillance is not desirable or possible
- Presence of any complications (e.g., nephrolithiasis, overt bone disease)
- An episode of hypercalcemic crisis
However, because no effective medical therapy for HPT exists, all patients with HPT who are otherwise healthy for surgery should be referred for surgical treatment.
Surgical Treatment.
Parathyroid surgery remains the single most effective treatment option in HPT and requires removal of all abnormal parathyroid tissue. Traditionally, in the vast majority of U.S. practices, this has meant bilateral exploration of the neck to identify all (typically four) parathyroids, assess which ones are abnormal, and remove only the abnormal glands. The setting of multiglandular hyperplasia requires subtotal parathyroidectomy or total parathyroidectomy, with reimplantation of parathyroid tissue into the sternocleidomastoid or forearm muscles. The parathyroids may then also be cryopreserved as a safeguard against future hypocalcemia, in which case the patient may undergo autotransplantation of autogenous, stored parathyroid tissue. In experienced hands, this approach has an exceptional rate of successful long-term cure of HPT (more than 96%) and a low rate of surgical complications (hypocalcemia less than 1%, recurrent laryngeal nerve injury 2% to 5%, neck hematoma or infection less than 1%). 8
In recent years, parathyroid procedures have been developed using smaller incisions under sedation and local anesthesia, and with the opportunity for outpatient surgery. Minimally invasive parathyroid surgery has become more frequently requested by patients and primary care physicians alike, even though it does not represent a uniform set of techniques. Depending on regional practices, minimally invasive parathyroid surgery can include laparoscopic, radio-guided or, most frequently, only unilateral neck surgery. The success of these approaches in curing HPT and minimizing complications is relatively unknown because clinical follow-up periods are still short. Minimally invasive parathyroid surgery is appropriate only for patients who have a single, clearly defined parathyroid abnormality on ultrasound, sestamibi scan, or both and when parathyroid hormone levels can be monitored intraoperatively. Bilateral neck exploration is mandatory in all other cases and for patients with familial or genetic syndromes.
Medical Treatment.
Patients who are not treated surgically should be managed to ensure good hydration and to avoid thiazide diuretics. Ambulation should be encouraged. Calcium intake should be average, because excessive intake may aggravate hypercalcemia, especially in patients with high calcitriol levels, whereas low calcium intake may stimulate PTH secretion. Bisphosphonates may be used to lower the serum calcium level in patients with symptomatic hypercalcemia (see later, “Treatment of Hypocalcemia”), although they are usually not effective.
