Noriko Isayama, Yusuke Uchimura, Kenta Sasaki, Erika Maeda, Megumi Watanabe, Sayaka Suzuki, Takeshi Mizuno
In humans, surgical repair is commonly performed for infective endocarditis (IE) associated with mitral valve destruction. However, extensive valve destruction may make repair impossible and require prosthetic valve replacement. In small-breed dogs, appropriately sized prosthetic valves are lacking, and complete surgical mitral valve reconstruction in dogs has not been reported. We encountered a Chihuahua that developed IE after mitral valve repair. During reoperation for progressive mitral regurgitation recurrence, the mitral leaflets were extensively destroyed and torn, and re-repair using native tissue was impossible; the entire valve was therefore reconstructed with fresh autologous pericardium. A graft was harvested and fashioned into a cylindrical valve based on a design previously described in a human study. Intraoperative saline testing and immediate postoperative echocardiography confirmed adequate opening and closure of the reconstructed pericardial valve, with only mild mitral regurgitation and no stenosis. The dog died on the second day after reoperative day of an uncontrolled infection caused by extended-spectrum beta-lactamase-producing Escherichia coli. This case demonstrates that an autologous pericardial valve can provide short-term mechanical function as a mitral valve in a small-breed dog and indicates that infection control is the principal determinant of outcome.