Primary hyperparathyroidism (PHPT) is the second most common disease treated by endocrine surgeons, with more than 100,000 new cases diagnosed annually in the United States.1 Success rates for treating hyperparathyroidism are regularly reported to be in excess of 95% in the hands of experienced parathyroid surgeons. However, these rates decrease to approximately 70% when the initial surgery is performed by an inexperienced surgeon.2 The morbidity associated with the initial operation for PHPT performed by a high-volume surgeon is minimal. Despite the excellent results reported for initial parathyroidectomies, those reported for reoperations are less impressive. After a failed initial operation, the success rate decreases, and the morbidity increases regardless of the experience of the operating surgeon. Claude Organ, MD, has been quoted as saying: "The decision to operate is the second hardest decision in surgery. The decision to reoperate is the hardest."
In 2002, the National Institutes of Health released a consensus statement regarding the treatment of patients with PHPT.3 This statement specifically addressed the treatment of asymptomatic patients who have elevated calcium and parathyroid hormone (PTH) levels and represents a transition to a broader recommendation for surgery in hyperparathyroid patients. In conjunction with this tolerant recommendation for surgery in asymptomatic patients, many authors now suggest a more inclusive definition of symptomatic patients that allows for more global signs and symptoms, such as fatigue, sleep disturbances, difficulty with concentration, polydipsia, and polyuria. Even with this paradigm shift, many surgeons remain more conservative when considering reoperation for patients with persistent or recurrent hyperparathyroidism. The indications for reoperation are less well defined and frequently depend on the overall condition of the patient and ability to localize abnormal parathyroid tissue.
Persistent hyperparathyroidism is defined as elevated calcium and PTH within 6 months of neck exploration for hyperparathyroidism, and recurrent hyperparathyroidism is defined as elevated calcium and PTH that occurs more than 6 to 12 months after a seemingly successful parathyroidectomy. Many factors have been implicated in persistent or recurrent hyperparathyroidism. Six major reasons for recurrent or persistent hyperparathyroidism have been identified.4 These include multiple gland disease (MGD), ectopic gland location, supranumerary glands, surgeon inexperience, persistent or metastatic parathyroid carcinoma, and errors on frozen section or intraoperative PTH monitoring.
MGD has been implicated in 31% to 37% of patients with persistent or recurrent hyperparathyroidism.2,5 Levine and Clark4 reported that 37% of failures were the result of MGD, with 22% of patients having hyperplasia and 15% having double adenomas. These numbers are much higher than the 10% to 15% and 3% to 5%, respectively, that are typically quoted for patients undergoing first-time operations for PHPT. This increased incidence likely reflects the lower sensitivity of current localization measures in identifying MGD.
In recent years, intraoperative PTH monitoring has been added to endocrine surgeons' armamentarium in an attempt to identify patients with MGD. This technique, initially described by Dr. George Irvin, uses the short half-life ...