Validation of Intracoronary Shunt Flow Measurements for Off-Pump Coronary Artery Bypass Operations
Introduction: Intracoronary shunting is a useful, easy and inexpensive technique to maintain blood flow during off-pump surgery to lessen myocardial ischemia. Intracoronary shunts should provide a minimal flow for adequate myocardial protection.
Material and Methods: Two commercially available shunts were used to measure flow from a bulb-size diameter of 1.00 mm to 3.00 mm (n = 10) in an in vitro setup. Shunts were perfused with Glycerin 47% solution at 37 ° C. Inlet pressure was raised continuously from 0 to 160 mmHg in all intracoronary shunts.
Results: In both groups (recipients of either type A shunt or type B shunt), mean pressure of 40 mmHg was necessary in shunts with diameter of 3.0 mm to provide a flow of approximately 50 mL/min. At mean pressure of 100 mmHg, a maximum flow of 126 mL/min was measured. Shunt B of 2.5-mm and 3.0-mm diameter showed similar flow patterns: 50 versus 52 mL/min at 40 mmHg and 98 versus 108 mL/min at 100 mmHg. Shunt A at 2.5-mm diameter showed 37 mL/min at 40 mmHg and 80 mL/min at 100 mmHg (P = .01). Shunt B at 1.5-mm diameter required 75 mmHg for approximately 40mL/min and showed maximum flow of 51 mL/min at 100 mmHg (P < .001). Only minimal flow was measured in 1.0-mm shunts of both groups.
Conclusions: There is a clear pressure/flow correlation in 2.0-mm to 3.0-mm shunts with maximum flow of 126 mL/min. Type B shunt of 1.5-mm and 2.5-mm diameter showed significant better flow rates. The possible value of 1.0-mm shunts is only in stenting and facilitating anastomosis and to obtain better visibility during anastomosis.
de Muinck ED, Verkerke BJ, Rakhorst G, Lie KI. 1994. Myocardial protection during coronary angioplasty with autoperfusion and forced perfusion: an in vitro comparison. Int J Artif Organs 17:83-7.nFranzone AJ, Wallsh E, Stertzer SH, DePasquale NP, Bruno MS. 1977. Reduced incidence of intraoperative myocardial infarction during coronary bypass surgery with use of intracoronary shunt technique. Am J Cardiol 39:1017-20.nGorge G, Erbel R, Haude M, et al. 1994. Continuous coronary perfusion balloon catheters in coronary dissections after percutaneous transluminal coronary angioplasty. Acute clinical results and 6-months follow-up. Eur Heart J 15:908-14.nKamiya H, Watanabe G, Kanamori T. 2003. Flow simulation of the intracoronary shunt tube for off-pump coronary artery bypass. Eur J Cardiothorac Surg 23:665-9.nKolessov VI. 1967. Mammary artery-coronary artery anastomosis as treatment for angina pectoris. J Thorac Cardiovasc Surg 54:535-44.nMuraki S, Morris CD, Budde JM, et al. 2002. Preserved myocardial blood flow and oxygen supply-demand balance with active coronary perfusion during simulated off-pump coronary artery bypass grafting. J Thorac Cardiovasc Surg 123:53-62.nPfister AJ, Zaki MS, Garcia JM, et al. 1992. Coronary artery bypass with out cardiopulmonary bypass. Ann Thorac Surg 54:1085-92.nRivetti LA, Gandra S M. 1997. Initial experience using an intraluminal shunt during revascularization of the beating heart. Ann Thorac Surg 63:1742-7.nTrapp VG, Bisarya R. 1975. Placement of coronary artery bypass graft without pump oxygenator. Ann Thorac Surg 19:1-9.nYeatman M, Caputo M, Narayan P, et al. 2002. Intracoronary shunts reduce transient intraoperative myocardial dysfunction during off-pump coronary operations. Ann Thorac Surg 73:1411-7.n
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