Reduction of functioning parathyroid cell mass by ethanol injection in chronic dialysis patients

Recent data suggest that the larger parathyroid glands are more resistant to calcitriol therapy than the smaller glands due to more severe reduction of calcitriol receptor number. To control severe secondary hyperparathyroidism resistant to calcitriol pulse therapy in chronic dialysis patients, we introduced repeatable and quantitative ethanol injection(s) into the largest parathyroid gland under ultrasonographic guidance with a specifically modified needle. Efficacy of each injection and the recurrence of hyperparathyroidism were confirmed by color Doppler ultrasonography and could undergo additional ethanol injection(s) into the optimal site. When the ethanol injection(s) into the largest gland was not sufficient to control PTH hypersecretion, we injected ethanol into the next largest gland. We performed 32 injections into 16 parathyroid glands in nine dialysis patients. PTH decreased to less than 200 pg/ml after the final injection in seven patients and they remained controlled either by the following conventional oral active vitamin D or calcitriol pulse therapy. The other two patients, whose PTH decreased but not to less than 200 pg/ml, also became controllable with the following calcitriol pulse therapy. Recurrent nerve palsy was encountered in 2 out of 32 injections, but only transiently. Our data suggest that the measurement of the size of parathyroid glands is an important factor in the management strategy of secondary hyperparathyroidism in chronic dialysis patients, and that ethanol injection(s) into the largest parathyroid gland(s) could be an effective and safe strategy to restore the responsiveness to calcitriol therapy, by reducing the functioning parathyroid cell mass most resistant to calcitriol.