The aim of the study was the characterization of calcification in the leaflets of a cryopreserved and alive heart valve depending on the diagnosed pathologic process. Sheep antibiotic sterilised and cryopreserved biological valves were implanted in tricuspid position in young sheeps for oneyear period. After this time the valves removed and studied morphologically. The control group consisted of 7 intact valves, the comparative group, so called group of valves after the processing antibiotic sterilization and cryopreservation consisted of 7 valves after mentioned procedures. Histological investigations were based on paraffin sections, calcium deposits were stained von Kossa technique. The measured values included integrative parameters as: 1. area fraction, 2. number of calcifications per area, 3. anisotropy. Conclusions: 1. A process of initial processing, sterilization and cryopreservation of biological valve increases a number of microcalcifications. 2. Cryopreserved biological valves explanted after one-year implantation into an animal in a tricuspid position posses fine calcifications and calcification foci. A number and size of fine calcifications decreases together with an intensification of degeneration and regressive processes of the connective tissue, especially in hyalinization. Hyalinization of the biological valve tissue seems to be favorable for a valve durability and as a pathological process decreasing calcification. 3. Mathematic analysis of morphometric features defining density and structure of calcifications indicate similarities among cryopreservation and initial processing groups, hyalinization, inflammation, whereas in a group of calcification foci, the similarity can be noticed between inflammation and hyalinization group.

Keywords: Heart, Biological Valve, calcification, Integrative Morphometr, Discriminant Analysis