Tissue regeneration observed in a porous acellular bovine pericardium used to repair a myocardial defect in the right ventricle of a rat model.
OBJECTIVE
Nonliving synthetic materials have been widely used to repair myocardial defects; however, material-related failures do occur. To overcome these problems, an acellular bovine pericardium with a porous structure fixed with genipin (the AGP patch) was developed.


METHODS
The AGP patch was used to repair a surgically created myocardial defect in the right ventricle of a rat model. A commercially available expanded polytetrafluoroethylene (e-PTFE) patch was used as a control. At retrieval, a computerized mapping system was used to acquire local epicardial electrograms of each implanted sample, and the appearance of each retrieved sample was grossly examined. The retrieved samples were then processed for histologic examination.


RESULTS
The amplitude of local electrograms on the AGP patch increased significantly with increasing implantation duration, whereas only low-amplitude electrograms were observed on the e-PTFE patch throughout the entire course of the study. No aneurysmal dilation of the implanted patches was seen for either studied group. Additionally, no tissue adhesion was observed on the outer (epicardial) surface of the AGP patch, whereas a moderate tissue adhesion was observed on the e-PTFE patch. On the inner (endocardial) surface, intimal thickening was observed for both studied groups; however, no thrombus formation was found. Intact layers of endothelial and mesothelial cells were identified on the inner and outer surfaces of the AGP patch, respectively. At 4 weeks postoperatively, smooth muscle cells, together with neomuscle fibers (with a few neocollagen fibrils), neoglycosaminoglycans, and neocapillaries, were observed to fill the pores in the AGP patch, an indication of tissue regeneration. These observations were more pronounced at 12 weeks postoperatively. In contrast, no apparent tissue regeneration was observed in the e-PTFE patch.


CONCLUSIONS
The present study indicated that the AGP patch holds promise to become a suitable patch for surgical repair of myocardial defects.
Chang
Yen
Y
Division of Cardiovascular Surgery, Veterans General Hospital-Taichung, and the College of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China.
Chen
Sung-Ching
SC
Wei
Hao-Ji
HJ
Wu
Tsu-Juey
TJ
Liang
Huang-Chien
HC
Lai
Po-Hong
PH
Yang
Hang-Hsing
HH
Sung
Hsing-Wen
HW
D000818:Animals; D001705:Bioprosthesis; D002417:Cattle; D004562:Electrocardiography; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D020007:Implants, Experimental; D057889:Iridoid Glycosides; D039823:Iridoids; D010496:Pericardium; D011138:Polytetrafluoroethylene; D016062:Porosity; D011714:Pyrans; D051381:Rats; D012038:Regeneration; D023822:Tissue Engineering
D057889:Iridoid Glycosides; D039823:Iridoids; D011714:Pyrans; D011138:Polytetrafluoroethylene; C007834:genipin