Resistance to tearing of calf and ostrich pericardium: Influence of the type of suture material and the direction of the suture line

Abstract

The tearing of the valve leaflet of a cardiac bioprosthesis can cause early failure of this device, which is employed to replace a diseased native valve. This report involves the study of the behavior of 312 tissue samples (152 of calf pericardium and 160 of ostrich pericardium) treated with glutaraldehyde and subsequently subjected to tear testing. The samples were cut in the two principal directions: longitudinally, or root to apex, and transversely. They included a series of control samples that were left unsutured, and the remaining samples were repaired with the use of two different suture techniques: a running suture in the direction of the load and a telescoping suture perpendicular to the load. Four commercially available suture materials were employed: Pronova, nylon, Gore-Tex, or silk. The unsutured control samples of both types of pericardium exhibited a similar anisotropic behavior in the tear test. The mean resistance to tearing of the calf pericardium was 24.29 kN m in samples cut longitudinally and 34.78 kN m in those cut transversely (p =.03); the values were 28.08 kN m and 37.12 kN m (p =.002), respectively, in ostrich pericardium. The series repaired with the telescoping suture always exhibited greater resistance to tearing, with values that ranged between 44.34 and 64.27 kN for the samples of calf pericardium and from 41.65 to 47.65 kN for those obtained from ostrich. These assays confirm the anisotropic behavior of calf and ostrich pericardium treated with glutaraldehyde when subjected to tear testing, as well as the loss of this behavior in ostrich pericardium after suturing. Suturing techniques, such as the telescoping model, that provide a greater resistance to tearing should be studied for use in the design of the valve leaflets of cardiac bioprostheses made of biological materials.

Correlation between compression, tensile and tearing tests on healthy and calcified aortic tissues

“…Many published data on the mechanical properties of aortic tissues is available. They postulate that the stress-strain relationship of aortic tissues is non-linear, viscoelastic and different under tension and compression [31,[34][35][36]. The behavior seen in the experiments was consistent with that observed in previous studies.…”

“…The resistance to tearing was expressed in Newton per millimeters, calculated, in agreement with the standard [31], according to the equation T = (F max /d), where T is the resistance to tearing, F max is the maximum load in Newton, and d is the thickness in millimeters.…”

Propagation of Tears in Pericardium From Young Bulls: Influence of the Suture

“…One of our research lines involves the study of the tearing of biomaterials that can be employed in the manufacture of prostheses or grafts. We consider that their resistance to tears might prove to be a good marker of the durability of the tissue (11–13). The greater the resistance to tearing of a biomaterial, the greater the force required to produce the tear or the longer the period of time over which this force must be exerted if its intensity does not vary; thus, the greater the durability.…”

Aortic endovascular repair modeling using the finite element method

“…Numerous research scientists have attempted to understand the biomechanics of the diagnosis or clinical treatment [21][22][23] and to make improvements to this intervention. Let us recall that it is minimally invasive and can treat complex arterial pathologies (aneurysms, stenosis, embolisms, etc.…”