Some, but not all, patients with primary hyperparathyroidism (PHPT) and kidney stone disease (KSD) are cured of their nephrolithiasis after parathyroidectomy. The goal of this study is to identify risk factors for recurrent KSD despite successful parathyroidectomy in known stone formers with PHPT.
We conducted a single-center retrospective review of patients presenting to Urology clinic with KSD between 1/2008 and 7/2018, who were diagnosed with concurrent PHPT, and underwent definitive parathyroidectomy. Laboratory testing for serum calcium, PTH, phosphorus and 25-OH-vitamin D, and 24-hour urine studies for volume, pH, calcium, citrate, oxalate, uric acid, sodium, and creatinine was performed pre- and post-parathyroidectomy. Stone recurrence was determined on routine diagnostic imaging or by symptomatic KSD.
Mean age at parathyroidectomy was 57±14years. Pre-parathyroidectomy, mean serum calcium, 24-hour urine calcium, and PTH were 10.6±0.5 mg/dL, 378±209 mg/day, and 114±97 pg/mL, respectively. 26/69 (38%) had multi-gland parathyroid disease. After parathyroidectomy, serum calcium and PTH levels normalized in 69/69 and 62/69 patients, respectively. However, 37/69 (54%) patients had persistent hypercalciuria post-operatively. 16/69 (23%) had recurrent KSD on average 2.0±1.6 years after parathyroidectomy. Patients with recurrent KSD post-parathyroidectomy were significantly younger compared to patients without recurrent KSD (51±15 vs. 60±13 years, p=0.02). In a logistic regression model, younger age remains a strong predictive factor for recurrent KSD.
Nearly a quarter of PHPT patients with KSD who undergo successful parathyroidectomy present with recurrent KSD despite normalization of serum calcium, and over half exhibit persistent calciuria. These patients were younger and may require closer monitoring for stone recurrence after successful parathyroidectomy. Further studies are needed to better identify the etiology of KSD post-parathyroidectomy.
Journal of the American College of Surgeons. 2020 Apr 21 [Epub ahead of print]
Ana K Islam, Shelby Holt, Joan Reisch, Fiemu Nwariaku, Jodi Antonelli, Naim M Maalouf
Department of Surgery, UT Southwestern Medical Center, Dallas, TX. Electronic address: ., Department of Surgery, UT Southwestern Medical Center, Dallas, TX., Population and Data Sciences, UT Southwestern Medical Center, Dallas, TX., Department of Urology, UT Southwestern Medical Center, Dallas, TX., Department of Internal Medicine and Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, UT Southwestern Medical Center, Dallas, TX.