Differential diagnosis between secondary hyperparathyroidism and aluminum intoxication in uremic patients: usefulness of 99mTc-pyrophosphate bone scintigraphy

Indications for parathyroidectomy and extent of treatment for patients with secondary hyperparathyroidism

Some manifestations of secondary hyperparathyroidism affect most if not all patients with chronic renal failure and can affect many different organ systems. Proper medical treatment is essential and should be attempted before considering surgical intervention. The symptoms that most often resolve after parathyroidectomy include bone pain and intractable pruritus. Other useful indications for operation include a marked elevation of the parathyroid hormone level and the elevation of the calcium x phosphate product over 70. Both subtotal parathyroidectomy and total parathyroidectomy with autotransplantation have been advocated as the best operative approach. Each of these procedures has its own advantages and disadvantages which should be considered for each individual case. Localizing procedures should be reserved for patients with persistent or recurrent hyperparathyroidism, as diffuse parathyroid hyperplasia is the most common operative finding in secondary hyperparathyroidism.

Scintigraphy in the clinical evaluation of disorders of mineral and skeletal metabolism in renal failure

In patients with renal bone disease skeletal and extra-skeletal abnormalities can be visualised using conventional bone scintigraphy. Some of these abnormalities are associated with characteristic scintigraphic appearances, which are reviewed in detail, and the possible mechanisms involved are discussed. Specific imaging with iodine 123 serum amyloid P component and iodine 131 beta 2-microglobulin is also discussed in the diagnosis of beta 2-microglobulin amyloidosis specific to patients on dialysis. In the light of available evidence, it appears that bone scintigraphy plays, so far, a limited role in the clinical evaluation of skeletal and extra-skeletal abnormalities in chronic renal failure. The potential role of bone scintigraphy in identifying patients with aluminium-related bone disease needs to be investigated further, and in this respect special attention must be given to the problem of high soft-tissue activity associated with impaired renal function. Timing haemodialysis sessions before scintigraphic imaging deserves wider recognition as it reduces high soft-tissue activity, thereby allowing bone uptake to be assessed more accurately. Specific imaging of amyloidosis resulting from beta 2-microglobulin deposition is a promising technique, but the relative value of the two proposed radiopharmaceuticals needs further clarification.

Results of reoperations for persistent or recurrent secondary hyperparathyroidism in hemodialysis patients

Among 258 patients operated on for secondary hyperparathyroidism (HPT II) from 1971 to 1988, a total of 33 had one or more reoperations for persistent or recurrent HPT II. These reoperations did not induce any mortality or significant morbidity. After inadequate parathyroidectomy (25 cases), 15 patients were reoperated. Twelve of these had undergone initial surgery at another institution. Three patients died of causes unrelated to their HPT II. The other 12 patients are disease-free. After successful subtotal parathyroidectomy (79 cases), 2 patients (2.5%) had a recurrence 5 and 6 years later, respectively. Currently, the 2 patients remain disease-free. After total parathyroidectomy with autotransplantation (152 cases), 16 patients (10.5%) had reoperations on the grafts. The mean time before reoperation was 2 1/2 years. Hypertrophy of grafted fragments was observed in 4 cases (2.6%), but only 2 of these 4 patients were cured by removal of the grafts. Residual parathyroid tissue or a supernumerary gland in the neck or the mediastinum was suspected in 5 patients, but this could not be confirmed because one had already been reoperated on in the neck without success, another still refuses reoperation, and 3 died. In 6 other patients, the recurrence was debatable and HPT II was not confirmed. In the last 3 patients, the diagnosis was incorrect and aluminum intoxication was proved later. Results of reoperations for persistent or recurrent HPT II depend, first, on a correct diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)