Predictors of recurrent hyperparathyroidism after total parathyroidectomy in chronic renal failure

Recurrent hyperparathyroidism (HPT) after total parathyroidectomy (TPTX) in chronic renal failure appears more common than might be anticipated.

To study its predictors, we reviewed all 20 cases of TPTX performed at our hospital in a 10-year period.

During follow-up (median 46.8 months (range 9.3-120.3)), 15 patients had measurable PTH levels (>10 pg/ml), 7 had levels above the normal range (recurrent HPT), and 3 had PTH levels >300 pg/ml (severe recurrent HPT). Total follow-up post-TPTX was equal in those who developed recurrent HPT and others, but those with recurrent HPT had spent longer on dialysis post-TPTX (61.9 +/- 34.9 vs. 21.8 +/- 12.0 months; p = 0.001). Patients with recurrent HPT required less vitamin D supplementation during the 10 days post-TPTX (p = 0.025). Log [maximal PTH post-TPTX] correlated with duration of dialysis dependency post-TPTX (r = 0.591, p = 0.006), lowest serum calcium level during the first 30 days post-TPTX (r = 0.449, p = 0.047), and mean serum calcium during the first 30 days post-TPTX (r = 0.546, p = 0.013). Mean log [maximal PTH post-TPTX] was significantly lower in patients with ectopic calcification (p = 0.047). In multiple regression analysis, duration of dialysis post-TPTX and lowest serum calcium level during the first 30 days post-TPTX were the only independent predictors of log [maximal PTH post-TPTX].

Recurrent HPT is common following TPTX and predicted by duration of dialysis dependency post-TPTX, a measure of overall exposure to the uraemic stimulus to parathyroid hyperplasia, and the degree of early hypocalcaemia, possibly reflecting the adequacy of operative parathyroid ablation.