Acute Stenosis of Porcine Stentless Bioprosthesis Caused by Infective Endocarditis
A 54-year-old man who underwent aortic valve replacement with a Prima Plus stentless bioprosthesis (Edwards Lifesciences, Irvine, Calif) with the use of a subcoronary technique 4 months previously was referred to our hospital with prosthetic valve endocarditis. Clinical symptoms and laboratory test data had been improving since the patient began antibiotic treatment; however, inflammatory markers remained, and blood cultures were positive for coagulase-negative staphylococci. Echocardiography revealed multiple vegetations on the prosthesis and a partial detachment of its proximal suture line (Movie I), but there was no aortic regurgitation because the distal suture line was intact and valve functions were well maintained. We decided to continue antibiotic therapy and perform surgery after the inflammation subsided. On the 5th day of hospitalization, the patient went into sudden cardiac arrest; he was given cardiopulmonary resuscitation, and a transesophageal echocardiographic examination was performed. The images in Figure 1 show long- and short-axis views of the left ventricular outflow in the diastolic (A and B) and systolic (C and D) phases. The posterior half of the proximal suture line was dehisced, causing it to thrust into the left ventricular outflow tract in systole and thereby causing severe stenosis; there was no aortic regurgitation in diastole. The transvalvular maximum pressure gradient was 125 mm Hg. A fully animated version of the process represented in Figure 1 can be viewed in the Movie II. Despite intensive support with the percutaneous cardiopulmonary support system, the patient died of multiorgan failure. The autopsy revealed multiple vegetations on the prosthesis, and the posterior half of the proximal suture was detached (Figure 2). Although this is a very rare case, stentless valves may cause acute stenosis because of their flexibility if prosthetic valve endocarditis occurs, whereas aortic regurgitation is the usual form of presentation with stented valves.
The online-only Data Supplement, which contains 2 movies, is available with this article at http://circ.ahajournals.org/cgi/content/full/114/19/e567/DC1.