|
|
||||||||
J Thorac Cardiovasc Surg 2001;121:0307-0315
© 2001 The American Association for Thoracic Surgery
Cardiopulmonary Support and Physiology |
From the Departments of Surgerya and Medicine,b Columbia University, New York City, NY.
This work was supported by a research grant from Percardia Inc, Nashua, NH.
Received for publication July 20, 2000. Revisions requested Aug 30, 2000; revisions received Sept 18, 2000. Accepted for publication Sept 19, 2000. Address for reprints: Daniel Burkhoff, MD, PhD, 177 Fort Washington Ave, MHB 5-435, New York, NY 10032 (E-mail: db59{at}columbia.edu).
Objectives: Trends in coronary bypass surgery require less invasive techniques and more conduits. We investigated the ability of direct coronary perfusion from the left ventricle to support regional and global cardiac function.
Methods: A conduit was established between the left ventricle and left anterior descending coronary artery (n = 6) with an interposed Starling resistor that allowed for graded regulation of backward flow. Changes of coronary flow, regional function in the territory of the left anterior descending coronary artery, and reactive hyperemia were studied. In 3 separate dogs, functional tolerance to increased heart rate was tested. In another 3 dogs, left ventricleleft anterior descending and left ventricleleft circumflex coronary artery conduits were established simultaneously (double conduit), and global function was tested.
Results: Without flow regulation, flow through the left ventricleleft anterior descending conduit exhibited high peaking (102 ± 35 mL/min), midsystolic forward flow, and large pandiastolic backward flow (peaking at 47 ± 22 mL/min). Mean coronary flow and regional function were maintained at 46.0% ± 7.1% (35.8%-54.2%) and 45.3% ± 29.1% (1.8%-74.2%) of their respective normal values. When the Starling resistor was used to regulate backward flow, these values increased to 70.8% ± 12.5% (56.8%-90.4%) and 70.2% ± 27.8% (23.6%-107.7%), respectively. Coronary and functional reserve with a left ventricleleft anterior descending conduit were not observed. With the double conduit, global ventricular contractility indexed by end-systolic pressure-volume relation averaged 46% ± 35% of its normal value.
Conclusions: A left ventriclecoronary artery conduit supplied approximately 45% of normal blood flow and regional function, and both were improved by regulation of backward flow. Therefore, a conduit from the left ventricle to an epicardial vessel could serve as a rapidly deployable means of revascularizing totally occluded coronary vessels for which suitable natural conduits are not available.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |