Once the decision for surgery has been made, a standard neck exploration to evaluate all 4 parathyroid glands is performed. Two approaches are used. One is a 3 and 1/2 gland resection. With this operation all parathyroid tissue except a portion of one gland is removed with the hope of reducing the PTH secretion to a more normal level. The goal is to alleviate symptoms, reduce the PTH and phosphate levels making control of the abnormal physiology simpler. The other operative approach is to remove all the parathyroid glands and re-implant a portion of one gland in the arm ( auto-transplantation) where, after 6-8 weeks, it will re-grow and function for the patient. The goals and outcomes are the same as with the 3 and 1/2 gland resection.
The thymus gland is removed with surgery for 2°HPT because, rarely, extra ectopic parathyroid glands may be associated with it. It is easily removed through the thyroidectomy incision. In adults, the thymus gland lays just below the thyroid gland behind he upper part of the breast bone. In young children, it may have an immunological function . In adults it is involuted and non-functional.
The operation that is recommended depends on the patients unique situation. Each approach has its own risks and advantages. With 3 and 1/2 gland resection, the remaining parathyroid gland functions immediately and usually post-op issues with hypocalcemia are less. However, with 2°HPT, recurrent hyperactivity of the remaining gland may occur, and if repeat surgery is needed, the risk of complications are elevated. With total parathyroidectomy and auto-transplantation, the transplanted gland won’t function for 6-8 weeks. Problems with low calcium are more more difficult to deal with. However if re-operation is required the grafted gland can more easily be approached, usually under local anesthesia.
All patients with 2°HPT require general anesthesia for surgery. The operation commonly last about 2 1/2 hours. All patients are observed over night and sometimes longer depending on their over all medical condition and degree of post-op hypocalcemia.