Influence of pressure load on durability of pulmonic xenobioprostheses in young adults.

The aim of this study was to investigate the effects of pressure load (pulmonary arterial pressure) on the long-term durability of second-generation xenobioprostheses in the pulmonary position in young adults. Thirteen patients survived pulmonary valve replacement for pulmonary regurgitation using the second-generation aortic porcine bioprosthesis at Sapporo Medical University School of Medicine between 1985 and 2009. The mean age at pulmonary valve replacement was 40.5 years, and the mean prosthetic valve size was 25.3 mm. Two patients developed structural valve deterioration 6 and 9 years, respectively, after pulmonary valve replacement. Both prosthetic valves with structural valve deterioration were subjected to long-term high levels of pressure load. No valve structural failure was observed in the remaining 11 patients who experience low-pressure load during a mean follow-up period of 11.9 years. The freedom from structural valve deterioration at 15 years was 75.8% for the overall population, but 100% for those with low-pressure load. Our findings suggest that the long-term durability of pulmonary-site bioprosthetic valves in young adult patients is promising but that pressure load might be a risk of the limited durability of the valve.