Surgical findings and post-operative parathormone levels in patients with secondary hyperparathyroidism

The peri-operative and immediate post-operative outcome of secondary hyperparathyroidism treated with subtotal parathyroidectomy is reported.

We studied 100 patients with chronic renal failure who underwent subtotal parathyroidectomy at our department. Surgical eligibility was based on hyperparathyroidism stage, defined by symptoms of osteodystrophy and/or the presence of hypercalcemia and hyperphosphatemia refractory to medical treatment. Parathormone levels were measured pre-operatively and during the first post-operative days.

During surgery, four parathyroid glands were identified in 86% of patients, five glands in 1%, and less than four glands in 13%. The ratio of hyperplastic to normal glands was 93:7. No correlation was found between anatomic location of the glands and the presence of hyperplasia. Parathormone decreased to normal or very low values in 93% of the patients. In seven cases, the lowest post-operative parathormone value was above 30 pg/ml, although four glands were removed in four of these patients. In 95% of the patients with four or more identified glands, post-operative serum parathormone levels decreased to normal or very low values. In 23% of the patients with less than four glands, parathormone levels remained too high. On the other hand, post-operative parathormone values normalized in 10 patients who had less than four glands identified during surgery; in two of them, parathyroid tissue was found during postoperative pathological examinations of the resected thyroid lobe.

Subtotal parathyroidectomy is an acceptable treatment in patients with refractory hyperparathyroidism. Our results indicate that there was not a perfect correlation between the number of identified glands and post-operative parathormone in a subset of patients.