The parathyroid risk in thyroid surgery. Argument against the early postoperative prescription of vitamin D. Experience with 729 thyroidectomies in 1988

: 729 consecutive patients underwent thyroidectomy in 1988 in the same institution, including 477 (68%) bilateral resections and 242 (33%) total thyroidectomies. An effort was made to see and save all 4 parathyroids and their blood supply. Early post-operative hypoparathyroidism was defined at day 5, by serum calcium less than 8 mg/dl. and serum phosphate less than 4 mg/dl or by serum calcium only if greater than 7.5 mg/dl. Patients afflicted with early hypoparathyroidism were given calcium tablets without any vit D for 1 year at most. Follow-up, checking serum Ca, P and i PIH was done on a 3 months basis during 1 year. Permanent hypoparathyroidism was defined by persistence of the above-mentioned criteria after 1 year, and eventually vit D was started. 27 patients (5.6% our of 477 bilateral thyroid resections) experienced early post-op hypoparathyroidism. Inciting factors were previous thyroid surgery (4), radioiodine treatment (2), modified neck dissection (2), sternal split with mediastinal node clearance (1), visualization of 1 parathyroid gland only (3 redo cases) and autotransplantation of more than 1 parathyroid (1 case). 1 patient was lost for follow-up. 25 others recovered a normal parathyroid function. 1 is permanently hypoparathyroid (1 redo case with other risk factors). Painstaking parathyroid dissection allows a 0% rate of permanent hypoparathyroidism after primary surgery, if vit D is not given in the early post-operative period. We suggest that avoidance of early vit D prescription in cases of early post-operative hypoparathyroidism, leading to mild sustained hypocalcemia, stimulates the spared parathyroid glands (including a possible 5th) and therefore allows full recovery of the parathyroid function.