Surgical treatment of primary hyperparathyroidism

Lithium therapy and hyperparathyroidism: an evidence-based assessment

BACKGROUND

Prolonged therapeutic exposure to lithium compounds can have adverse consequences on calcium homeostasis. A unique form of hyperparathyroidism appears to be causally linked to chronic lithium exposure. We provide a comprehensive review of relevant literature using a structured, evidence-based approach.

METHODS

Published data were identified from systematic electronic literature searches. References are assigned a level of evidence according to a validated classification schema.

RESULTS

Level III and V evidence supports an etiologic link between sustained lithium therapy and both hypercalcemia and hyperparathormonemia (grade C recommendation). Level V evidence supports the use of preoperative parathyroid imaging if a focused exploration is planned (grade C recommendation). Level V evidence supports the use of intraoperative parathyroid hormone monitoring to guide appropriate surgical therapy (grade C recommendation). There is conflicting and equally weighted level V evidence supporting a routine preoperative plan of bilateral neck exploration versus selective unilateral exploration (no recommendation). There may be a role for calcimimetic drug therapy as an alternate, nonsurgical means of controlling lithium-associated hyperparathyroidism (grade C recommendation).

CONCLUSIONS

Evidence-based recommendations support screening of patients on chronic lithium therapy for hypercalcemia. Appropriate surgical therapy may consist of either a bilateral or a unilateral approach when performed by an experienced endocrine surgeon. Focused approaches should be guided by preoperative imaging and intraoperative hormone monitoring. Calcimimetic therapy is a potential alternative to parathyroidectomy.

Appropriate surgical treatment of lithium-associated hyperparathyroidism

BACKGROUND

Lithium is frequently used in the treatment of bipolar disease. Although lithium-associated hyperparathyroidism (LAH) is well documented, reports concerning its pathologic findings are sparse. Because of a high-reported incidence of multiglandular disease, focused exploration for LAH is controversial.

METHODS

From 1995 to 2007, data from 1207 consecutive patients who underwent concise parathyroid exploration for sporadic primary hyperparathyroidism (PHP) directed by quick intraoperative parathyroid hormone monitoring (QPTH) were reviewed to identify patients with LAH. Anatomic findings were determined. All patients had >5 months of follow-up.

RESULTS

The incidence of LAH was 16/1207 (1.3%). The rate of multiglandular disease was not higher in LAH: present in 25% (4/16) patients with LAH and 12.3% (146/1191) patients without LAH (p = 0.13 Fisher two-tailed test). Among 16 patients with LAH, 12 (75%) had a single adenoma. The use of QPTH allowed unilateral exploration in 8 of 12 patients with single adenoma. Parathyroid exploration resulted in durable biochemical cure for all 16 patients with LAH.

CONCLUSION

Multiglandular disease seems to be no more frequent in patients with LAH than in patients with primary hyperparathyroidism (PHP) without LAH. Patients with LAH can be safely and effectively managed with selective unilateral exploration directed by intraoperative PTH monitoring.