Electromechanical characterization of a tissue-engineered myocardial patch derived from extracellular matrix

• Published in: The Journal of thoracic and cardiovascular surgery Vol. 133; no. 4; pp. 979 - 985
• Main Authors: Ota, Takeyoshi, MD, PhD, Gilbert, Thomas W., PhD, Badylak, Stephen F., DVM, MD, PhD, Schwartzman, David, MD, Zenati, Marco A., MD
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Mosby, Inc 01.04.2007; AATS/WTSA; Elsevier
• Subjects: Animals; Biological and medical sciences; Cardiothoracic Surgery; Disease Models, Animal; Electrocardiography; Extracellular Matrix - pathology; Extracellular Matrix - physiology; Extracellular Matrix - transplantation; Heart - physiology; Medical sciences; Myocardium - pathology; Regeneration; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Swine; Tissue Engineering; Ventricular Remodeling - physiology; 34; UBM; 24; RV; right ventricular; intracardiac echocardiography; SMA; 18; ICE; LV; urinary bladder matrix; ECM; SVR; linear local shortening; LLS; surgical ventricular restoration; left ventricular; left ventricular assist system(s); smooth muscle actin; extracellular matrix; LVAS; Characterization; Heart; Treatment; Tissue engineering; Surgery; Tissue culture; Myocardium; Extracellular matrix; Thorax; Patch
• ISSN: 0022-5223; 1097-685X
• DOI: 10.1016/j.jtcvs.2006.11.035

Objective Extracellular matrix scaffolds have been successfully used for myocardial wall repair. However, regional functional evaluation (ie, contractility, electrical conductivity) of the extracellular matrix scaffold during the course of remodeling has been limited. In the present study, we evaluated the remodeled scaffold for evidence of electrical activation. Methods The extracellular matrix patch was implanted into the porcine right ventricular wall (n = 5) to repair an experimentally produced defect. Electromechanical mapping was performed with the NOGA system (Biosense Webster Inc, Diamond Bar, Calif) 60 days after implantation. Linear local shortening was recorded to assess regional contractility. After sacrifice, detailed histologic examinations were performed. Results Histologic examinations showed repopulation of the scaffold with cells, including a monolayer of factor VIII–positive cells in the endocardial surface and multilayered α-smooth muscle actin–positive cells beneath the monolayer cells. The α-smooth muscle actin–positive cells tended to be present at the endocardial aspect of the remodeled scaffold and at the border between the remodeled scaffold and the normal myocardium. Electromechanical mapping demonstrated that the patch had low-level electrical activity (0.56 ± 0.37 mV; P < .0001) in most areas and moderate activity (2.20 ± 0.70 mV; P < .0001) in the margin between the patch and the normal myocardium (7.58 ± 2.23 mV). Conclusions The extracellular matrix scaffolds were repopulated by α-smooth muscle actin–positive cells 60 days after implantation into the porcine heart. The presence of the cells corresponded to areas of the remodeling scaffold that showed early signs of electrical conductivity.