1. A Rapid Structural Degeneration of a Porcine Mitral Valve
Takashi Miura, MD, Shiro Hazama, MD, Keisuke Iwasaki, MD, Kenta Izumi, MD, Seiji Matsukuma, MD, Kiyoyuki Eishi, MD 
The Annals of Thoracic Surgery 
Volume 93, Issue 5, Pages e113-e114 (May 2012)
DOI: /j.athoracsur
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Porcine heart valve prostheses explanted after 12 months. (A) Mitral valve, flow surface. The 3 cusps were thinning, and 2 of them were perforated. One cusp had 2 perforations of 2 mm and 5 mm, and the other cusp had a pinhole perforation. (B) Aortic valve, flow surface. The prosthesis shows pannus overgrowth on the flow surface partially covering the cusps.
The Annals of Thoracic Surgery  , e113-e114DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Histologic section of the excised mitral valve. The surface was infiltrated with histiocytes and multinucleated giant cells. Lymphocytes and neutrophils infiltrated into valvular tissue. (F = flow surface; NF = non–flow surface; hematoxylin and eosin, ×10.)
The Annals of Thoracic Surgery  , e113-e114DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Histologic sections of the excised mitral valve. (A) Necrotic valvular tissue with histiocytes was noted around the perforation (hematoxylin and eosin, ×4). (B) Macrophages (positive for CD68) were observed around the perforation (immunohistochemical test for CD68 stain, ×4). (F = flow surface; NF = non–flow surface; P = perforation.)
The Annals of Thoracic Surgery  , e113-e114DOI: ( /j.athoracsur )
Copyright © 2012 The Society of Thoracic Surgeons Terms and Conditions