[Viability of parathyroid gland tissue measured by flow cytometry]

Postoperative hypoparathyroidism after the total parathyroidectomy (PTX) remains a problem, no matter our experiences with 243 operations on parathyroid glands (PG). Implantation of "fresh" tissue, cryopreservation and reimplantation of cryopreserved tissue are performed with uncertain results. The aim of this project was to compare viability of cryopreserved tissue of parathyroid glands with "fresh" tissue obtained during parathyreoidectomy and with tissue from cadaverous donors.

Group 1 included 55 cryopreserved samples obtained from 41 patients after PTX (22M, 19F, a mean age of 46 +/- 11 years). Average duration of storage in liquid nitrogen was 84 +/- 49 months. Group 2 included "fresh" tissue of PG, harvested during PTX. Viability was measured in different time in samples from 42 patients with hyperparathyroidism (11M, 31F, a mean age of 55 +/- 13 years). Group 3 included tissue of 14 cadaverous donors obtained during multiorgan harvesting (7M, 7F, a mean age of 31 +/- 5 years, WIT 32 min). Viability was measured by flow cytometry with propidium iodide after dissociation of tissue. Evaluation of PG tissue was proven by histology. Average viability in group 1 was 36.9 +/- 24.7%, no correlation with the duration of storage in liquid nitrogen was found. Average viability in group 2 was 51.4 +/- 24%. Viability in group 3 was 66.8 +/- 32%. Group 1 vs. group 2 were different with p < 0.05, group 2 vs. 3 did not reach significance (with marginal p = 0.06) and group 1 vs 3 were different with p < 0.001.

The highest viability was found in tissue of cadaverous donors, the lowest in cryopreserved tissue (with no correlation to the duration of storage in liquid nitrogen).