Renal stones and primary hyperparathyroidism: natural history of renal stone disease after successful parathyroidectomy.

The aim of the study was to evaluate the risk of renal stone recurrence after successful surgical treatment of primary hyperparathyroidism (pHPT). Of 297 consecutive patients with surgically verified pHPT, 151 patients had had renal stone disease; a total of 113 patients were eligible for follow-up; and of these, 107 patients remained normocalcemic during follow-up and formed the study group. The number of new stones were calculated by subtracting the stones present on preoperative urograms from the number of stones on urograms after 1, 3, and 5 years and the number of stones passed or eliminated by intervention. Among 107 patients, 32 (30%) formed one to four new stones within 5 years. This recurrence rate is comparable to the expected recurrence rate in idiopathic stone formers. Primary hyperparathyroidism and renal stone disease are common. As all renal stone formers are screened for pHPT by serum calcium analysis, the two diseases might by coincidence be found in the same patients. A considerable number of patients with pHPT and renal stone disease therefore experience recurrence of their stone disease irrespective of the presence of normocalcemia after successful parathyroidectomy.