Endocrine Surgery: Thyroid and Parathyroid
摘要
Secondary hyperparathyroidism (SHPT) is common in patients affected by chronic kidney disease (CKD); furthermore, an increased prevalence of hypothyroidism, nodular goiter and thyroid carcinoma are shown in these patients when compared with the general population. In SHPT, the excessive secretion of parathyroid hormone (PTH) is a response to the reduction in serum calcium concentration. This explains why the PTH level is elevated while the serum calcium is normal, even though most CKD patients frequently develop hypercalcemia, and all patients develop bone and cardiovascular complications. Patients on long-term dialysis or after kidney transplantation may experience tertiary hyperparathyroidism, where the parathyroid glands may become hypertrophic with autonomous function and inappropriately increased levels of PTH with hypercalcemia. Most patients manage to control the disease with medical treatment, with only a fraction requiring surgery. International guidelines suggest that patients with PTH more than 9 times the normal range, hypercalcemia and/or hyperphosphatemia refractory to medical treatment should be considered for parathyroidectomy. Parathyroidectomy correlates with improvement of cardiovascular and bone morbidity, and with an improved quality of life. Bilateral four-gland exploration should be conducted in all patients, and three different surgical approaches are described: total parathyroidectomy without autotransplantation, total parathyroidectomy with autotransplantation and subtotal parathyroidectomy. The rate of postoperative complications after surgery is higher than that of surgery for primary HPT, and the most common postoperative complication is hypocalcemia.