Endocrine Abstracts

Introduction: Persistent hyperparathyroidism is reported to occur in 0–6% of cases after initial surgery for sporadic primary hyperparathyroidism (PHPT). The management of these cases is complex, however, with a poor cure rate despite repeated surgery. The aim of our study was to identify the challenges and pitfalls encountered in the management of a series of patients with persistent hyperparathyroidism after initial parathyroidectomy.

Patients and methods: Using the Leiden University Medical Center hospital records, we identified 20 patients with sporadic PHPT who had undergone 33 revision surgeries for persistent hyperparathyroidism. Clinical, operative and histology data were documented from the patients’ notes.

Results: The most common cause of persistent HPTH was a missed ectopic gland at initial surgery (33%), followed by missed multiglandular disease (15%). The least common cause was parathyromatosis (9%), with its risk increasing with repeated surgery. Pre-operative localization studies had poor sensitivity: US 18%, MRI 20%, Tc99m-MIBI-SPECT 25%, CT scan 30%. In contrast, selective venous sampling for PTH had a sensitivity of 50% and a specificity of 89%. The decrease in intraoperative PTH was significantly less marked (63±26% vs 89±11, P=0.003) and less rapid in patients in whom PHPT persisted compared to those who achieved cure. The risk of complications, particularly recurrent laryngeal nerve palsy, increased with each subsequent surgery: 20% after the first, 50% after the 2nd and 67% after the 3rd revision surgery.

Conclusion: Persistent PHPT represents a significant management challenge largely due to the poor predictive value of pre-operative localization studies and to increased risk of complications with each subsequent surgery. Intraoperative PTH decreases operating time and thus risk of complications. Cases of parathyromatosis are the most challenging, with decreased likelihood of cure after repeated surgery. The potential of calcimimetics in the management of these patients remains to be explored.