| Internal thoracic artery flow competition: studies in a canine H-graft model. | |
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MedLine Citation:
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PMID: 12493505 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECTIVE: Internal thoracic artery (ITA) flow competition is a diversion of graft flow through intact ITA branches with a net decrease in perfusion to the grafted coronary. Although a widely acknowledged phenomenon, the conditions under which flow competition occurs have not been established. This is examined in a canine H-graft model. METHODS: Eight dogs had a right ITA segment interposed (H-graft) between their in situ left ITA (LITA) and the snared left anterior descending (LAD) coronary artery. Proximal LITA and H-graft flows were measured at baseline and during pacing-induced tachycardia, phenylephrine-induced hypertension, and nitroprusside-induced hypotension. Flows were measured with the distal LITA open and occluded. Two additional animals were subjected to eight separate 2-min periods of LAD ischemia, after which post-ischemic H-graft flow measurements were obtained with and without distal LIMA occlusion. RESULTS: During baseline conditions, proximal LITA flow was greater when the distal LITA was open rather than occluded (46+/-15 versus 35+/-12 ml/min, respectively; P=0.002), but H-graft flow did not change significantly (32+/-18 versus 35+/-18 ml/min, respectively; P=0.21). Similarly, occlusion of the distal LITA had no impact on H-graft flow during tachycardia, hypertension, or hypotension. Only in animals subjected to transient LAD ischemia did H-graft flow increase with distal LITA occlusion, albeit marginally (65+/-7-70+/-9 ml/min, occluded versus open, respectively; P=0.04). CONCLUSIONS: Mild diversion of flow from the LAD was demonstrated during immediate post-ischemic coronary reperfusion only, and could not be elicited under any other physiologic condition. These data suggest that flow competition is unlikely to constitute a clinically significant limitation to the use of H-grafts or other modalities that leave ITA branches patent. |
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Authors:
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William E Cohn; Marc Ruel; Jian Ping Zhang; Frank W Sellke; Robert G Johnson |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery Volume: 23 ISSN: 1010-7940 ISO Abbreviation: Eur J Cardiothorac Surg Publication Date: 2003 Jan |
Date Detail:
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Created Date: 2002-12-20 Completed Date: 2003-03-20 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8804069 Medline TA: Eur J Cardiothorac Surg Country: England |
Other Details:
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Languages: eng Pagination: 56-9 Citation Subset: IM |
Affiliation:
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Division of Cardiothoracic Surgery, Beth Israel Deaconess Medical Center, LMOB 2A, 110 Francis Street, Boston, MA 02215, USA. wcohn@caregroup.harvard.edu |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Coronary Artery Bypass* Coronary Disease / physiopathology*, surgery Coronary Vessels / physiology*, surgery Dogs Models, Animal Myocardial Reperfusion Postoperative Period Regional Blood Flow Thoracic Arteries / physiology*, surgery |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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