Background

Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD), especially in the later stages. Parathyroidectomy (PTX) is recommended for patients who do not respond to medical treatment. However, in some cases, SHPT may persist due to incomplete gland resection or recur as a result of hyperplasia of remnant tissue. The aim of this study was to evaluate PTX outcomes in CKD patients treated at our center and identify predictors of persistent disease.

Methods

A retrospective, descriptive and analytical study was conducted on CKD patients who underwent PTX for SHPT between January 2014 and January 2024 at Sahloul University Hospital in Tunisia. The analysis covered demographic, clinical, biochemical, radiological and surgical data. SHPT diagnosis was defined as intact parathormone (iPTH) > 585 pg/mL on at least two separate occasions, associated with hyperphosphatemia, hypocalcemia or normocalcemia, and resistance to ≥ 6 months of optimized medical therapy (phosphate binders, vitamin D analogs, calcimimetics), in line with KDIGO guidelines. Vitamin D deficiency was corrected before confirming the diagnosis. Persistent SHPT was defined as a iPTH level over 585 pg/mL three to six months after surgery.

Results

A total of 100 patients were included. The mean age was 44.9 ± 14.1 years; 96% were in stage 5 CKD, of whom 83% were on hemodialysis, 11% on peritoneal dialysis, and 6% were pre-dialysis. Four patients (4%) had late stage 4 CKD with imaging and histological confirmation of secondary origin, excluding primary hyperparathyroidism. Bone pain was present in 26% of patients and hypoalbuminemia in 42%. Scintigraphy detected enlarged glands in 97% of cases. Subtotal PTX was performed in 82% of cases, total PTX in 17%, and total PTX with autotransplantation in 1%. Persistent SHPT occurred in 30% of patients. Mean resected gland volume was 1.8 ± 0.7 cm³ in persistent SHPT vs. 1.1 ± 0.5 cm³ in remission (p = 0.01), with a positive correlation between gland volume and postoperative iPTH levels (r = 0.41, p = 0.003). Predictors of persistence included bone pain, hypoalbuminemia, metabolic acidosis, upper right gland hyperplasia, and incomplete resection.

Conclusion

PTX is an effective treatment for refractory SHPT, but persistence occurs in one-third of cases. Preoperative clinical and biochemical factors may help identify patients at risk. A multidisciplinary evaluation and complete resection are crucial.

Clinical trial number

Not applicable.