Long-term results of subcutaneous parathyroid grafts in uremic patients

Hypothesis: Parathyroid glands are normally surrounded (entirely or partial ly) by fatty tissue. Subcutaneous parathyroid grafts are thus located in a normal environment. Therefore, we postulated that the late results of subcu taneous implantation of parathyroid tissue in uremic patients should be at least as good as those reported for intramuscular grafting. We also challen ged the idea that the recurrence rate of renal hyperparathyroidism after su rgery depended solely on the type of hyperplasia (diffuse: vs nodular) obse rved in the implanted tissue. Design: A retrospective study of a series of patients without loss to Follo w-up. Setting: A university hospital and 9 affiliated dialysis units. Patients and Interventions: Fifty-nine patients (33 women and 26 men) opera ted on for renal hyperparathyroidism underwent the resection of at least 4 parathyroid glands followed by presternal subcutaneous implantation of para thyroid tissue. They were followed up for 12 to 130 months (median, 38 mont hs). Main Outcome Measures: Failure of treatment, recurrence of disease, and hyp oparathyroidism. Results: During the study period, 9 patients had to undergo another operati on: 2 (3%) for persistent hyperparathyroidism due to a fifth ectopic gland and 7 (12%) for recurrence of hyperparathyroidism resulting from hypertroph y of the subcutaneous grafts. Four patients received a kidney transplant. T he prevalence of hypoparathyroidism (intact parathyroid hormone serum level <1.6 pmol/L with a normal or low serum calcium concentration) was 14% (8 o f 59 patients), and the curve representing the distribution of intact parat hyroid hormone serum concentrations among operated on patients was shifted to the left when compared with the curve of patients who underwent hemodial ysis and who had no indication for parathyroid surgery. In this latter grou p, the peak of the curve was situated between 1 and 2 times the upper norma l limit, while it tvas in the normal range 12 to 130 months after total par athyroidectomy and subcutaneous parathyroid autotransplantation. No relatio n was observed between the recurrence rate of the disease and the histologi cal characteristics of the parathyroid grafts. Also, their function was not influenced by the presence or absence of aluminium deposits in bone biopsy specimens that were obtained at the time of cervical exploration. Conclusions: The late results of total parathyroidectomy and presternal sub cutaneous grafting compare favorably with the published data on other surgi cal techniques proposed for the treatment of renal hyperparathyroidism. The ease with which the hypertrophied grafts are removed when the disease recu rs warrants further use of this procedure.