title: Thermal welding of biological tissues derived from porcine aorta for manufacturing bioprosthetic cardiac valves.
abstract: Sutures in cardiac valve bioprostheses have several disadvantages as they have to be manually processed and the suturing region is always a mechanically weak spot. Thermal welding of biological tissues has been evaluated as a means of replacing sutures by the direct application of heat to tissues. The mechanical strength of the welds increased up to 50°C and with lower degrees of humidity and longer times of welding. Chemical fixation was essential for the stability of the weld during re-hydration. The average mechanical strength of the welds (0.87 MPa) was lower than the strength of sutures (1.36 MPa) but some results showed strengths that were similar to sutures. Raman and electron micrographs showed that weld formation is primarily associated with chemical bonds between collagen fibers rather than chain flow and interpenetration.
authors.affiliation: St. Jude Medical Inc, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Rubem L P
authors.initials: RL
authors.lastname: Figueiredo
authors.forename: Maria Sylvia Silva
authors.initials: MS
authors.lastname: Dantas
authors.forename: Rodrigo L
authors.initials: RL
authors.lastname: Oréfice
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001011:Aorta; D001696:Biomechanical Phenomena; D005976:Glutaral; D006350:Heart Valve Prosthesis; D006358:Hot Temperature; D006813:Humidity; D008422:Materials Testing; D011474:Prosthesis Design; D013059:Spectrum Analysis, Raman; D013552:Swine; D013718:Tensile Strength
chemical_list: D005976:Glutaral