Design and manufacture of heart valve bioprostheses and vascular grafts

Technology

A computerized machine for precision manufacture of prosthesis parts using laser

               Computer Thickness Map                    Laser Cutting in the Shape of the Selected Patterns
 maplaser  laser

In 2007, an automated xenopericardium laser cutting system was commissioned, which has no equivalents in the world and can significantly enhance product to product consistency.

Computer technology for leaflets production featuring pericardium thickness detection prior to cutting ensures consistent quality of the leaflet apparatus for each of the valve prosthesis. Maximum thickness homogeneity of the leaflet apparatus facilitates even stress distribution across the entire leaflet surface.

Unique features of the laser machine:

  • measuring pericardial tissue thickness and topographical mapping to show pericardium thickness;
  • automatic patterns location in accordance with the required thickness of the patch and high precision laser cutting of the pericardium - to 10 microns;
  • laser patch cutting technology allows to completely avoid collagen fibers splitting along the edge of the cut and to preserve the whole structure of the biomaterial;
  • laser radiation parameters allow to obtain a smooth edge.
Scissors Scalpel Laser
s1 s2 s3

Biological Prostheses Preservation Method

Bioprostheses, preserved with epoxy compounds, feature several advantages:

  • High resistance to calcification;
  • The biomaterial cross-linking density is 35% higher than that of the biomaterial, treated with glutaraldehyde, thereby increasing robustness by 20%;
  • Enhanced hydrophilic properties of the epoxy treated biomaterial increase elasticity by 10%, i.e. biomechanics is as close to the characteristics of the native material as possible;
  • Preservation with diepoxy compound enhances biomaterial biocompatibility and improves its hydrodynamic properties;
  • Using epoxy compounds protects biological material from microorganisms and retroviruses.

Additional Biological Prostheses Treatment

  • Antibacterial activity of biomaterials is achieved by immobilization of chlorhexidine, while reducing the microbiological contamination by gram-negative and gram-positive bacteria. This technology was approved for clinical use by the Ministry of Health of the Russian Federation.
  • Anti-calcium modification. The technology is covered by a patent of the Russian Federation. Immobilized diphosphonates can effectively inhibit the processes of biomaterial calcification. Modification with diphosphonates does not cause destructive changes in the epoxy treated tissue, maintaining its elasticity and increasing robustness by 56%.
  • Antithrombotic modification. Additional treatment with various types of heparin enhances bioprostheses thromboresistant properties. Unfractionated heparin is well established in antithrombotic modification of bioprostheses.