Parathyroidectomy does not necessarily lower the incidence of symptomatic stone events, at least for several years after surgery.

In patients with primary hyperparathyroidism and nephrolithiasis, we tend to assume that parathyroid surgery will lower risk for future symptomatic stone events substantially. But three recent observational studies have called that assumption into question. In all three studies, patients who underwent parathyroidectomy were compared with patients who were observed without surgery, and all studies were adjusted extensively for potentially confounding variables.

• In a study drawn from the US Veterans Affairs Healthcare database, researchers identified 5600 patients with primary hyperparathyroidism and clinical histories of kidney stones. Compared with observed patients, those who underwent parathyroidectomy had a slightly higher rate of recurrent symptomatic stone events during the two years after surgery. But during the next several years of follow up, rates of recurrent stone events were similar in the two groups.
• A study from the Kaiser Permanente health system in California included about 1200 patients with primary hyperparathyroidism and histories of symptomatic nephrolithiasis. Rates of recurrent symptomatic stones were similar in surgically treated and observed patients during mean follow up of eight years.
• In a third study, 7600 patients with primary hyperparathyroidism were identified in an insurance claims database. Five-year rates of kidney stone events were similar in patients who underwent parathyroid surgery and those who were observed; the similarity was noted whether or not patients had previous symptomatic nephrolithiasis.

Comment: I was initially surprised by these results. However, patients with symptomatic nephrolithiasis often have small asymptomatic stones within the kidney; some of those stones eventually will descend into the ureter and cause symptoms, even after the predisposing metabolic defect – the hyperparathyroidism – has been corrected. For patients with mild, otherwise asymptomatic primary hyperparathyroidism, the authors of these reports speculate that an uncomplicated kidney-stone history should not necessarily be the decisive factor in determining whether to perform parathyroidectomy.
ALLAN S. BRETT, MD
Clinical Professor of Medicine, University of Colorado School of Medicine, Aurora, USA.

Seib CD, et al. Kidney stone events following parathyroidectomy vs nonoperative management for primary hyperparathyroidism. J Clin Endocrinol Metab 2022; 107: e2801-e2811.
Huang S-Y, et al. Parathyroidectomy for nephrolithiasis in primary
hyperparathyroidism: beneficial but not a panacea. Surgery 2022; 171: 29-34. 
Seib CD, et al. Association of parathyroidectomy with 5-year clinically significant kidney stone events in patients with primary hyperparathyroidism. Endocr Pract 2021; 27: 948-955.

This summary is taken from the following Journal Watch title: General Medicine.