Hyperparathyroidism is a common endocrine disorder usually cured by subtotal parathyroidectomy. Parathyroid overactivity documented by appropriate laboratory studies may be associated with general hyperplasia of the parathyroid glands or with an adenoma involving one of the four or more parathyroid glands. Kidney stones, gastrinoma, recurrent pancreatitis, or other conditions are some of the clinical disorders that imply a disorder of the parathyroid glands. Hypercalcemia is discovered as a result of more frequent calcium determinations performed as part of a general screening survey. Hyperparathyroidism is associated with gastrinoma in approximately one-third of patients with the familial multiple endocrine syndrome I (MEN I). A mitogenic cause for the relatively high incidence of recurrent hyperparathyroidism in the familial MEN I syndrome suggests the need for a radical approach, which may consist of total parathyroidectomy with autotransplantation of parathyroid slices into the muscle in the nondominant forearm or removal of 3½ parathyroid glands.
Evidence of hyperparathyroidism associated with hypercalcemia of 12 mg/dL after renal transplantation may be an indication to consider a radical parathyroidectomy. Hypercalcemia and extremely high parathyroid hormone (PTH) values may occur after renal transplantation. This condition often resolves spontaneously, usually within a year of the transplantation. In general, a conservative observational approach should be taken within the first 2 years after renal transplantation, with operative intervention on the parathyroids only in patients who demonstrate progressive bone disease and who are clearly symptomatic.
Parathyroidectomy should precede surgical procedures for gastrinoma in patients with the MEN I syndrome. There is an apparent increase in supernumerary parathyroid glands in those with the familial MEN I syndrome, which suggests the need to remove the thymus, where an accessory parathyroid gland may be located when the cervical exploration is negative. More rarely, thyroidectomy may also be considered in a valiant search for a parathyroid gland buried within the thyroid gland if a parathyroid is not visible under the thyroid capsule.
The presence of one endocrine tumor suggests the desirability of a general search for other endocrine tumors, such as gastrinoma, pheochromocytoma, prolactinoma, and others, before parathyroidectomy is performed.
Recurrence of hyperparathyroidism after a parathyroidectomy requires a review of previous surgical procedures and a review of the pathologist’s report on the parathyroids. Were the usual four glands found, and where were they? Were any glands verified in the thyroid, thymus, anterior or posterior mediastinum, or above the thyroid? Which glands were removed or verified by frozen section examination? Every effort should be made to localize the parathyroids prior to any reoperation. Computed tomography, magnetic resonance imaging, radionuclide (sestamibi), and ultrasound scans may be useful for identifying large tumors. However, selective venous sampling with hormonal assays may be the last and best diagnostic option.
The surgeon should be familiar with the usual locations of the parathyroid glands as well as their common areas of migration (figure 1). ...