Unusual 30-year durability of Hancock II porcine bioprosthesis in tricuspid position.

INTRODUCTION: We describe an unusual durability of a Hancock II porcine bioprosthesis in tricuspid position. Sustainability of bioprostheses is known to be limited especially in young patients. PRESENTATION OF THE CASE: A 52-year old Caucasian woman with a history of multiple valve interventions. Her clinical presentation of dyspnoea and lower limb oedema led to the diagnosis of severe tricuspid valve stenosis and right heart failure, and was managed by the replacement of the tricuspid bioprosthesis by another bioprosthesis 30-years after the initial implantation. DISCUSSION: Calcification is the leading cause of bioprosthesis structural deterioration. This immune-induced phenomenon is more pronounced in young patients. Although several patient-related and valve-related factors influence the durability of a xenograft, unknown factors may be of some importance. CONCLUSION: To our knowledge, this is the first report of a 30-year durability of tricuspid bioprosthesis in a young recipient. In the absence of extensive calcifications, pannus formation covering the whole prosthesis, peculiar hemodynamics and other unknown factors might have contributed to an extended durability in this young patient.

Gonococcal ascending aortic aneurysm with penetrating ulcer and bovine arch.

We describe a patient with ascending aorta aneurysm and bovine aortic arch who initially presented with fever. A 65-year-old man with a 2-month history of intermittent fever was referred to our hospital and diagnosed as having a gonococcal ascending aorta aneurysm with penetrating ulcers. He was successfully treated by resection of the ascending aorta and ulcers, replacement of the aortic valve, and prolonged postoperative antibiotic therapy.

Readily available porcine aortic valve matrices for use in tissue valve engineering. Is cryopreservation an option?

The clinical use of acellular biological valves as scaffolds in tissue valve engineering would require them to be readily available. This study examines the feasibility of cryopreserving porcine aortic valve matrices for use in tissue valve engineering. Matrices prepared using an enzymatic-detergent decellularization protocol were examined before and after cryopreservation. The biochemical status of tissues were evaluated by collagen and uronic acid (proteoglycan) determination and their mechanical properties were determined using a burst test. The histological and ultrastructural properties were evaluated by light and electron microscopy. Cryopreservation did not significantly affect the collagen and uronic acid content of aortic leaflet matrices. Histological and ultrastructural sections, however, confirmed extensive disruption of the extracellular collagen matrix and inter-fibrillar proteoglycan associations following cryopreservation. Although neither the breakage force nor the maximum force at failure was significantly different in matrices before and after cryopreservation, the strain observed in matrices was significantly higher after cryopreservation. To our knowledge this is the first study to investigate the effects of cryopreservation on aortic valve matrices. Cryopreservation did not significantly alter the biochemical properties of porcine aortic valve matrices. Nevertheless, cryopreservation had significant adverse effects on the structural and mechanical properties of matrices. Cryopreserved matrices showed significantly higher strain when stressed compared to non cryopreserved matrices. While, theoretically matrices are only expected to be functional for a limited time until regenerated in vivo, further mechanical testing is necessary to evaluate the effects of these changes on the durability of porcine aortic valve matrices for use in tissue valve engineering.