Month: November 2024

Multimed Man Cardiothorac Surg. 2024 Sep 11;2024. doi: 10.1510/mmcts.2024.038.

ABSTRACT

In treating aortic root diseases, the Bentall procedure offers reliable and stable results. However, it requires a prosthetic valved conduit, which presents inherent challenges due to the need for anticoagulation. The Ozaki procedure, which uses pericardium for aortic valve neocuspidization, is an alternative to prosthetic valves and does not need anticoagulation. We developed a surgical technique combining the Bentall and Ozaki procedures to treat patients with aortic root disease, which we describe in this article. Because the risk of bleeding due to anticoagulation after prosthetic valve replacement was a concern, we combined the Bentall and Ozaki procedures with a graft conduit using bovine pericardial patch neocuspidization. Postoperative echocardiography showed a competent aortic valve with no regurgitation. We believe that this novel procedure provides hope for a more adaptable and patient-friendly option.

PMID:39258523 | DOI:10.1510/mmcts.2024.038

J Mech Behav Biomed Mater. 2024 Dec;160:106741. doi: 10.1016/j.jmbbm.2024.106741. Epub 2024 Sep 11.

ABSTRACT

Transcatheter aortic valve replacement (TAVR) has become today the most attractive procedure to relieve patients from aortic valve disease. However, the procedure requires crimping biological tissue within a metallic stent for low diameter catheter insertion purpose. This step induces specific stress in the leaflets especially when the crimping diameter is small. One concern about crimping is the potential degradations undergone by the biological tissue, which may limit the durability of the valve once implanted. The purpose of the present work is to investigate the mechanical damage undergone by bovine pericardium tissue during compression and analyze how this degradation evolves with time under fatigue testing conditions. Pericardium 500 μm thick pericardium ribbons (5 mm large, 70 mm long) were crimped down to 12 Fr for 30 and 50 min within a metallic stent to replicate the heart valve crimping configuration. After crimping, samples underwent cyclic fatigue flexure and pressure loading over 0.5 Mio cycles. Samples were characterized for mechanical performances before crimping, after crimping and after fatigue testing in order to assess potential changes in the mechanical properties of the tissue after each step. Results bring out that the ultimate tensile strength is not modified through the process. However an increase in the modulus shows that the crimping step tends to stiffen the pericardium. This may have an influence on the lifetime of the implant.

PMID:39276437 | DOI:10.1016/j.jmbbm.2024.106741

J Mech Behav Biomed Mater. 2024 Dec;160:106741. doi: 10.1016/j.jmbbm.2024.106741. Epub 2024 Sep 11.

ABSTRACT

Transcatheter aortic valve replacement (TAVR) has become today the most attractive procedure to relieve patients from aortic valve disease. However, the procedure requires crimping biological tissue within a metallic stent for low diameter catheter insertion purpose. This step induces specific stress in the leaflets especially when the crimping diameter is small. One concern about crimping is the potential degradations undergone by the biological tissue, which may limit the durability of the valve once implanted. The purpose of the present work is to investigate the mechanical damage undergone by bovine pericardium tissue during compression and analyze how this degradation evolves with time under fatigue testing conditions. Pericardium 500 μm thick pericardium ribbons (5 mm large, 70 mm long) were crimped down to 12 Fr for 30 and 50 min within a metallic stent to replicate the heart valve crimping configuration. After crimping, samples underwent cyclic fatigue flexure and pressure loading over 0.5 Mio cycles. Samples were characterized for mechanical performances before crimping, after crimping and after fatigue testing in order to assess potential changes in the mechanical properties of the tissue after each step. Results bring out that the ultimate tensile strength is not modified through the process. However an increase in the modulus shows that the crimping step tends to stiffen the pericardium. This may have an influence on the lifetime of the implant.

PMID:39276437 | DOI:10.1016/j.jmbbm.2024.106741