Cryopreservation of Parathyroid Glands for Deferred Autologous Transplant in the Management of Hyperparathyroidism with Surgical Indication

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; SPIRA, C

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

Hyperparathyroidism (HPT) is caused by excessive production of parathyroid hormone (PTH) by the parathyroid glands. HPT is classified as primary or secondary depending on its underlying cause. The treatment of this condition depends on the severity and its cause. Both subtotal and total parathyroidectomy, with or without autologous transplant are therapeutic alternatives. In order to prevent permanent postsurgical hypoparathyroidism, one of its main surgical complications, several techniques have been developed including cryopreservation of parathyroid tissue for deferred autologous transplant. Technology Cryopreservation allows storage of parathyroid tissue by means of a process involving freezing which allows preservation of parathyroid tissue function for further reimplantation. Purpose To assess the evidence available on the efficacy, safety and coverage policy related aspects on the use of cryopreservation of parathyroid glands in patients with hyperparathyroidism undergoing surgery. Methods A bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems. Results Two retrospective studies, one prospective study and one coverage policy were selected. One retrospective multicenter study published in 2010, assessed the function of 22 (1.6%) out of 1,376 cryopreserved parathyroid samples from 20 transplanted patients. The average cryopreservation period was 11.1 months. After a 26-month follow-up, 10% were fully functional (defined as normal calcium and PTH levels with no calcium and vitamin D supplementation), 10 % were partially functional (moderate hypocalcemia and normal PTH, requiring calcium and/or vitamin D supplementation requirements) and 80% were non-functional (hypocalcemia and low PTH levels, requiring calcium and/or vitamin D supplementation). A similar prospective study, published in 2005, assessed the function of 30 cryopreserved parathyroid samples from 26 patients, followed-up for 24 months. Out of the 30 grafts, 12 (40%) were fully functional, 6 (10%) partially functional and the remaining 12 (40%), non-functional. The average preservation period for functional grafts was 7.9 months, whereas for the non-functional ones was 15.3 months (p