Abandoning unilateral parathyroidectomy: why we reversed our position after 15,000 parathyroid operations.

BACKGROUND: Our group championed the techniques and benefits of unilateral parathyroidectomy. As our experience has matured, it seems this limited operation might be appropriate only occasionally.

METHODS: A single surgical group's experience with 15,000 parathyroidectomies examined the ongoing differences between unilateral and bilateral techniques for 10-year failure/recurrence, multigland removal, operative times, and length of stay.

RESULTS: With limited experience, 100% of operations were bilateral, decreasing to 32% by the 500(th) operation (p < 0.001), and long-term failure rates increased to 6%. Failures were 11 times more likely for unilateral explorations (p < 0.001 vs bilateral), causing gradual increases in bilateral explorations to 97% at the 14,000(th) operation (p < 0.001). Ten-year cure rates are unchanged for bilateral operations, and unilateral operations show continued slow recurrence rates of 5% (p < 0.001). Removal of more than one gland occurred 16 times more frequently when 4 glands were analyzed (p < 0.001), increasing cure rates to the current 99.4% (p < 0.001). Of 1,060 reoperations performed for failure at another institution, intraoperative parathyroid hormone levels fell >50% in 22% of patients, yet a second adenoma was subsequently found. Operative times decreased with experience; bilateral operations taking only 5.9 minutes longer on average (22.3 vs 16.4 minutes; p < 0.001), which is 25 minutes less than unilateral at the 500(th) operation (p < 0.001). By the 1,000(th) operation, incision size (2.5 ± 0.2 cm), anesthesia, and hospital stay (1.6 hours) were identical for unilateral and bilateral procedures.

CONCLUSIONS: Regardless of surgical adjuncts (scanning, intraoperative parathyroid hormone), unilateral parathyroidectomy will carry a 1-year failure rate of 3% to 5% and a 10-year recurrence rate of 4% to 6%. Allowing rapid analysis of all 4 glands through the same 1-inch incision has caused us to all but abandon unilateral parathyroidectomy.