[Total thyroidectomy with identification of parathyroid glands. Functional implications]

Several factors have been involved in the pathogenesis of postoperative hypocalcemia after total thyroidectomy (TT). The real cause is yet unclear, but postoperative (p.o), hypoparathyroidism seem s to be the most important factor.

337 patients underwent TT; a systematic and accurate identification and preservation of parathyroid glands was always performed. In all patients calcemia was evaluated before and after surgery (1St, 2nd, 4th, 15th, and 30th day), moreover in 90 patients was also evaluated phosphorus, magnesium, alkaline phosphatase, total proteins, PTH, calcitonin serum levels and urinary levels of calcium and phosphorus.

No permanent hypocalcemia was observed and transient hypocalcemia was present in 13.6% of patients. Among 90 patients, 84 showed normal calcium serum levels like the others parameters; the other 6 showed a post-operative hypocalcemia associated with clinical symptoms, an increase of phosphoremia and a decrease of PTH and phosphaturia in early p.o days; in these patients calcemia and PTH levels reached normal values within 30 days after surgery.

The surgical manipulation of parathyroid glands should be the cause of lowering of PTH serum concentration and transient hypocalcemia.