Direct Left Ventricle-to-Coronary Artery Stent Restores Perfusion to Chronic Ischemic Swine Myocardium
DOI:
https://doi.org/10.1532/HSF98.20061021Abstract
Background. Direct left ventricle (LV)-to-coronary artery shunts (VSTENT) have been proposed as an alternative means of myocardial revascularization. The goal of this study was to examine quantitative changes in myocardial perfusion and possible mechanisms of revascularization with an LV-to-coronary shunt.
Methods. Ameroid occluders were implanted on the proximal left anterior descending coronary artery (LAD) of 6 pigs to create chronic ischemia. Four weeks later, a VSTENT was placed to directly connect the distal LAD with the LV chamber. Animals survived for an additional 3 weeks and received periodic bromodeoxyuridine (BrdU) injections to identify dividing cells to identify and quantify angiogenesis. Regional myocardial perfusion (RMP) was measured with color microspheres under adenosine vasodilatory stress before and 3 weeks after VSTENT implantation. Vascularity was assessed histologically by an overall vascularity index and a growth index reflecting the density of BrdU-positive vascular cells.
Results. Three weeks after VSTENT placement, RMP improved from 38.4% ± 19.6% of non-ischemic flow to 86.8% ± 13.7% in treated animals (P < .05). This benefit was accompanied by histological evidence of increased vascularity and vascular proliferation. Four of 5 animals had patent and functional devices at the end of the study.
Conclusion. Chronic VSTENT placement improves RMP and may promote arterial remodeling in chronically ischemic porcine myocardium.
References
Almeda FQ, Parrillo JE, Klein, LW. 2003 Alternative therapeutic strategies for patients with severe end-stage coronary artery disease not amenable to conventional revascularization. Catheter Cardiovasc Int 60:57-66.nAmerican Heart Association. 2001. 2002 heart and stroke statistical update. Dallas: American Heart Association.nEmery R, Carrel T, Wolf RK, et al. 2004. Description and evaluation of a ventriculo-coronary artery bypass device that provides bi-directional coronary flow. Eur J Cardiothorac Surg 25:43-50.nFrazier OH, March RJ, Horvath KA. 1999. Transmyocardial revascular-ization with a carbon dioxide laser in patients with end-stage coronary artery disease. N Engl J Med 341:1021-8.nKantor B, McKenna CJ, Caccitolo J, et al. 1999. Transmyocardial and percutaneous myocardial revascularization: current and future role in the treatment of coronary artery disease. Mayo Clinic Proc 74:585-92.nKohmoto T, Fisher PE, Gu A, et al. 1996. Does blood flow through holmium:YAG transmyocardial laser channels? Ann Thorac Surg 61:861-8.nKowallik P, Schulz R, Guth BD, et al. 1991. Measurement of regional myocardial blood flow with multiple colored microspheres. Circulation 83:974-82.nMukherjee D, Bhatt DL, Roe MT, et al. 1999. Direct myocardial revascularization and angiogenesis: how many patients might be eligible? Am J Cardiol 84:598-60.nOesterle SN, Yeung AC, Lo S, et al. 2000. Percutaneous in-situ coronary venous arterialization (PICVA) improves survival in response to acute ischemia in the porcine model. J Am Coll Cardiol 35:61A.nRoethy W, Fiehn E, Suehiro K, et al. 2001. A growth factor mixture that significantly enhances angiogenesis in vivo. J Pharm Exp Therap 299:494-500.nSimons M, de Muinck ED. 2004. Re-evaluating therapeutic neovascularization. J Molecular Cellular Card 36:25-32.nStone GW, Teirstein PS, Rubenstein R, et al. 2002. A prospective, multicenter, randomized trial of percutaneous transmyocardial laser revascularization in patients with nonrecanalizable chronic total occlusions. J Am Coll Cardiol 39:1581-7.nSuehiro K, Shimizu J, Yi GH, et al. 2001. Direct coronary artery perfusion from the left ventricle. J Thorac Cardiovasc Surg 121:307-15.nTomanek RJ, Doty MK, Sandra A. 1998. Early coronary angiogenesis in response to thyroxine. Circ Res 82:587-93.nUnger EF, Sheffield CD, Epstein SE. 1990. Creation of anastomoses between an extracardiac artery and the coronary circulation: proof that myocardial angiogenesis occurs and can provide nutritional blood flow to the myocardium. Circulation 82:1449-66.nYamamoto N, Kohmoto T, Gu A, et al. 1998. Angiogenesis is enhanced in ischemic canine myocardium by transmyocardial laser revascularization. J Am Coll Cardiol 31:1426-33.nYeung AC, Hayase M, Fitzgerald P, et al. 1999. Percutaneous in-situ coronary artery bypass (PICAB): current development status and preliminary results of a novel myocardial revascularization technique. J Am Coll Cardiol 33(suppl):47A.nYi GH, Becker EM, Dang NC, et al. 2005. Intramyocardial left ventricle-to-coronary artery stent: a novel approach for the treatment of coronary artery disease. Ann Thorac Surg 80:600-6.n
