DIAGNOSTIC OF DYSFUNCTION OF REIMPLANTED PARATHYROID TISSUE BY BILATERAL DETERMINATION OF INTACT PARATHYROID-HORMONE LEVELS IN CUBITAL VENOUS-BLOOD - A PROSPECTIVE ANALYSIS

Aim: In a prospective long-term follow-up study after operative therap y of hyperparathyroidism the value of bilateral determination of parat hyroid hormone levels in cubital venous blood after total parathyroide ctomy/autologous parathyroid gland reimplantation (musculus brachiorad ialis) for diagnosis of dysfunctioning grafted tissue is evaluated. Pa tients and material: From August, 1, 1987 to March, 31, 1994 68 of 243 patients operated on for hyperparathyroidism underwent total parathyr oidectomy. Autologous reimplantation of parathyroid gland was carried out simultaneously in 64 patients. Twice delayed reimplantation of cry opreserved tissue was carried out, and there was no reimplantation in two patients up to this day. Three patients were operated on for hyper functioning parathyroid autograft after former total parathyroidectomy /reimplantation. Results: During follow-up 5 patients developed dysfun ction of (reimplanted) parathyroid gland. Because of low or unprovable levels of intact parathormone the gradients of intact parathyroid hor mone between grafted and nongrafted forearm were about 1:1 in postoper ative hypoparathyroidism as well as in hypofunction of parathyroid gla nd. After successful replantation of cryopreserved parathyroid tissue gradients of intact parathyroid hormone increased (> 1:10). In hyperfu nction of grafted parathyroid tissue hormone gradients were high (> 1: 20 to 1:45,3) because of excessive high levels of intact parathormone in the cubital vein of the graft bearing arm. Successful reduction of parathyroid graft was followed by decrease of parathyroid hormone grad ients. Conclusion: Regular follow-up of intact parathormone gradients together with intact parathyroid hormone levels and serumcalcium analy sis allow the determination of parathyroid graft function. Also differ entiation between graft dependant hyperparathyroidism and hyperfunctio ning parathyroid tissue in the neck or mediastinum seems to be possibl e by bilateral determination of intact parathormone. Normal values or a normal range for intact parathyroid hormone gradients can not yet be defined.