Surgical verification of percutaneous maxacalcitol injection therapy on enlarged parathyroid glands in chronic dialysis patients.

Selective percutaneous ethanol injection therapy (PEIT) has been used to control parathyroid function in patients with secondary hyperparathyroidism (2HPT) when one or more parathyroid gland (PTG) progresses to the nodular hyperplasia stage. However, PEIT can have adverse side effects, such as nerve paralysis and adhesion, because the ethanol is destructive. Intraparathyroid injection of a vitamin D analogue has been designed as a treatment to control parathyroid function without destruction of the PTG or causing adhesions to the surrounding tissue, and the present study aimed to verify the effect of percutaneous maxacalcitol (22-oxacalcitriol) as the vitamin D analogue. The study group comprised two haemodialysis patients who needed parathyroidectomy for uncontrolled 2HPT with a maximal PTG diameter >20 mm. The treatment began with an ultrasonographically guided injection of 10 microg of maxacalcitol solution into the largest PTG and, 1 week later, parathyroidectomy was performed to examine the effect of the maxacalcitol injection both macroscopically and microscopically. The injected glands were swollen and inflamed, and adhesions made it difficult to remove them. There was macroscopic and microscopic evidence of haemorrhagic necrosis and adhesions to the surrounding tissue. Direct vitamin D analogue injection should not be performed as a primary treatment option because the adverse side effects are not overcome by this technique.