[Surgical therapy concept in primary hyperparathyroidism]

Primary hyperparathyroidism is a relatively rare disease caused in 80-85% of cases by solitary adenoma of the parathyroid glands. The laboratory findings are hypersecretion of PTH and hypercalcaemia. We distinguish between asymptomatic and symptomatic primary hyperparathyroidism. 25 patients of our clinic who underwent surgery in 1996 and 1997 are presented to illustrate our surgical concept of therapy.

7 patients were asymptomatic and 18 symptomatic with regard to primary hyperparathyroidism. Preoperative localisation was facilitated by ultrasonography of the neck, which was used in all cases. Bilateral exploration of the neck under general anaesthesia similarly to thyroidectomy was the gold standard. Monitoring the inferior laryngeal nerve helped to protect it. In 6 cases intraoperative parathyroid hormone monitoring (rapid PTH assay) was applied.

More than a third of the symptomatic group of patients had neurological or psychiatric diseases, followed by symptoms of the musculoskeletal and urological systems. Possible reasons for surgical intervention were persistent hypercalcaemia, age over 50, radiological findings of kidney stones or decreased kidney function. In 17 patients the preoperative ultrasonographic localisation was consistent with the intraoperative clinical findings. The sensitivity of this method was 68%. Intraoperative pathology showed 17 patients with a solitary adenoma, 4 ectopic, 2 cases had double adenoma, and 2 others hyperplasia with enlargement of all glands. After resection of the pathological parathyroid glands there was a decrease of parathyroid hormone in intraoperative hormone monitoring of approximately 60%. The preoperative hypercalcaemia (mean 2.99 mmol/l) usually normalised 4 hours postoperatively. There was no severe intraoperative bleeding and the inferior laryngeal nerve was preserved in all cases. All patients were monitored at 3-month intervals for parathyroid hormone and serum calcium during the first year after operation. One patient had persistently elevated parathyroid hormone without clinical findings.

Parathyroidectomy is an efficient and safe operation with excellent normalisation of serum calcium and parathyroid hormone and a high rate of patient satisfaction. In this study assessment of ultrasonography was the preferred method of locating enlarged parathyroid glands before operation. However, this method is not based on unilateral exploration of the glands. Therefore, we prefer to locate all four glands, an approach based on the literature [1, 2]. Intraoperative monitoring of parathyroid hormone facilitates assessment of the operative result [3]. Normalisation of calcium in serum and the effectiveness and safety of the surgical method are confirmed in other publications [4-8]. In 24 of our patients normocalcaemia resulted within 12 hours after operation and in one patient within 4 days. One year after operation and endocrinological checkup all 25 patients were asymptomatic and normocalcaemic, while one patient had persistently high parathyroid hormone of unknown origin.