Hyperparathyroidism: historical milestones and modern therapeutic strategies.

The Viennese Medical School was at the forefront of the clinical understanding of the relationship between parathyroid and bone metabolism. A century ago, F. Mandl (1925) and E. Gold (1927) described two patients clinically (osteitis fibrosa cystica) and biochemically (hypercalcemia, hypercalciuria) with a disease which Gold had already termed (primary) hyperparathyroidism (PHPT) in 1928. The two patients were successfully treated by removing one enlarged parathyroid gland each. After the clinical and biochemical diagnosis was confirmed, surgery was recommended. In 1933, Mandl summarized his rules postulating bilateral cervical exploration, i.e. the macroscopic assessment of all four glands. Only enlarged glands should be removed. Until the beginning of the 1990s, in the hands of highly experienced endocrine surgeons, bilateral neck exploration was the undisputed method of choice (gold standard) with a high postoperative success rate (normocalcemia: 98-99%). Sporadic PHPT is predominantly caused by one hyperactive parathyroid gland. The development of reliable imaging techniques in combination with intraoperative parathyroid hormone (PTH) monitoring to verify the completeness of parathyroid tissue resection led to a change in surgical strategy from extended to limited explorations. The targeted (focused) exposure of the prelocated enlarged gland with the aim to reduce surgical trauma, yet resulting in the same high cure rates, was introduced. For targeted exploration, various endoscopic techniques, cervical or remote access (i.e. skin incision outside the neck), have become available. The more direct the access, the less invasive is the dissection. Surgical techniques minimizing trauma and followed by less pain should be favored. Therefore, the direct open (mini-incision) technique with short neck incision seems to be the new gold standard.