TOTAL PARATHYROIDECTOMY WITH AUTOGRAFT IN PATIENTS ON DIALYSIS - PTH GRADIENT AS ASSESSMENT OF PARATHYROID FUNCTION

The aim of our study was to evaluate the function and growth oi parath yroid tissue autografted into the forearm of total parathyroidectomize d patients in dialysis. In sixteen parathyroidectomized patients, with autograft in the forearm, a longitudinal retrospective study was perf ormed, comparing the level of parathyroid hormone on samples from both forearms (PTH gradient); calcium and phosphorus values; and evaluatin g hyperparathyroidism syntomatology and treatment postparathy-roidecto my. The patients were divided in two groups: Group I (n = 6): patients with signs of recurrent hyperparathyroidism: PTH increased, sintomato logy, hypercalcemia and/or hyperphosphatemia; Group II (n = 10): patie nts that show decrease of PTH after parathyroidectomy and are asymtoma tic. In all patients of group I, a PTH gradient (relation between PTH from implant forearm versus PTH nonimplant) greater than or equal to 5 was measured. In four out of six patients extirpation of parathyroid autograft tissue was performed. PTH decreased significantly after surg ery, and gradient PTH decreased in three of them. In all but one patie nt from group II a gradient < 5 was measured. No significant PTH gradi ent was found in 2 patients. In one of them, PTH gradient was assayed four years after parathyroidectomy, so we think that the autograft was not functioning. No significant differences in calcium, oral calcium and calcitriol doses postparathyroidectomy between two groups were fou nd. Group I patients had higher phosphorus values than group II. The f recuence of recurrence was higher when autografted tissue with nodular hyperplasia than autografted tissue with diffuse hyperplasia. In conc lusion, measurements of PTH gradient in patients with total parathyroi dectomy with forearm autograft, is a useful method to assays autograft function. PTH gradient greater than or equal to 5, PTH increased afte r parathyroidectomy associated to hyperparathyroidism signs (hypercalc emia or hyperphosphoremia and sintomatology), in our experience, sugge st recurrence of hyperparathyroidism and is indication of reinterventi on. In these cases the reintervention gets good results.