Porcine vena cava as an alternative to bovine pericardium in bioprosthetic percutaneous heart valves

Abstract

Percutaneous heart valves are revolutionizing valve replacement surgery by offering a less invasive treatment option for high-risk patient populations who have previously been denied the traditional open chest procedure. Percutaneous valves need to be crimped to accommodate a small-diameter catheter during deployment, and they must then open to the size of heart valve. Thus the material used must be strong and possess elastic recoil for this application. Most percutaneous valves utilize bovine pericardium as a material of choice. One possible method to reduce the device delivery diameter is to utilize a thin, highly elastic tissue. Here we investigated porcine vena cava as an alternative to bovine pericardium for percutaneous valve application. We compared the structural, mechanical, and in vivo properties of porcine vena cava to those of bovine pericardium. While the extracellular matrix fibers of pericardium are randomly oriented, the vena cava contains highly aligned collagen and elastin fibers that impart strength to the vessel in the circumferential direction and elasticity in the longitudinal direction. Moreover, the vena cava contains a greater proportion of elastin, whereas the pericardium matrix is mainly composed of collagen. Due to its high elastin content, the vena cava is significantly less stiff than the pericardium, even after crosslinking with glutaraldehyde. Furthermore, the vena cava’s mechanical compliance is preserved after compression under forces similar to those exerted by a stent, whereas pericardium is significantly stiffened by this process. Bovine pericardium also showed surface cracks observed by scanning electron microscopy after crimping that were not seen in vena cava tissue. Additionally, the vena cava exhibited reduced calcification (46.64 ± 8.15 μg Ca/mg tissue) as compared to the pericardium (86.79 ± 10.34 μg/mg). These results suggest that the vena cava may enhance leaflet flexibility, tissue resilience, and tissue integrity in percutaneous heart valves, ultimately reducing the device profile while improving the durability of these valves.

Impact of percutaneous pulmonary valve implantation procedural steps on leaflets histology and mechanical behaviour: An in vitro study

“…However, we can also conclude that BJV leaflets are a resilient substrate, affected slightly by traumatic injury. Munelly et al analysed the mechanical behaviour of bovine pericardium after compression under forces similar to those exerted by valved stent crimping; they showed that bovine pericardium was significantly stiffened by this process, with an increase in elastic modulus [25]. We also found an increase in bovine pericardium elastic modulus in our compression group (condition II).…”

First quantification of alpha‐Gal epitope in current glutaraldehyde‐fixed heart valve bioprostheses

“…In fact, according to Munnelly et al. , the mechanical crimping procedure seems to be able to alter the ECM organization likely increasing exposure of previously masked epitopes.…”

Donkey pericardium compares favorably with commercial xenopericardia used in the manufacture of transcatheter heart valves

“…After the site of deployment is confirmed, the valve is deployed and fixed in place using a balloon catheter or through self‐expansion . A major limitation of TAVI is due to the potential damage to the heart valve during crimping and balloon inflation, making the pericardium tissue more elastic and less resilient resulting in transverse fractures . In our previous commentary, similar effects of crimping and expansion on the transcatheter heart valve were described .…”