title: Improving patency of coronary conduits "valveless" veins and/or arterial grafts.
abstract: BACKGROUND
  Veins used for coronary artery bypass operation have a well-documented limited long-term patency. Internal thoracic artery (ITA) grafts have shown exceptional "durability." Assumptions were made that other arterial conduits have similar characteristics.
  
  
  OBJECTIVE
  The purpose of this article is to compare different conduits long-term patency including saphenous veins to other available arterial conduits: inferior epigastric artery (IE), right gastroepiploic artery (RGEA), and radial artery (RA).
  
  
  METHODS
  Recent studies have shown that radial artery bypasses have lower patency rate than saphenous veins. Flow patterns, physiological flow characteristics are reviewed including native vessel disease and area of myocardium supplied. In the case of venous bypasses, the primary culprit of failure seemed to be the quality of the vein itself and the reverse venous valves in the conduit resulting in: (a) trapping-hypertension, (b) thrombosis, (c) turbulence, (d) intimal damage, (e) mismatching in size.
  
  
  RESULTS
  Clinical follow-up of our patients up to 8 to 11 years (average 8.9 years) have proved the superior characteristics of the so-called "good veins." In a retrospective study of 436 patients sequential, valveless veins patency was 88.6% versus 72% of reversed valvular segments (p < 0.01). Patients' survival seemed to be significantly improved if these veins were combined with ITA grafts. Patients' survival with one valveless limb HS + ITA was 78% versus HS + SV 52% (p < or = 0.0017) and HS + ITA versus HS + ITA + SV (p < 0.0057).
  
  
  CONCLUSIONS
  Selective decision-making of the surgeon at the time of the operation is required to choose the best conduit to be able to perform the best operation with the best long-term result.
authors.affiliation: State University of New York at Buffalo, NY, USA. tzlajos007@aol.com
authors.forename: Thomas Z
authors.initials: TZ
authors.lastname: Lajos
authors.forename: Francis
authors.initials: F
authors.lastname: Robicsek
authors.forename: Mano
authors.initials: M
authors.lastname: Thubrikar
authors.forename: Harold
authors.initials: H
authors.lastname: Urschel
mesh_terms: D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000503:physiopathology* / Q000601:surgery*; D019074:Epigastric Arteries / Q000503:physiopathology; D024405:Gastroepiploic Artery / Q000503:physiopathology; D006083:Graft Occlusion, Vascular / Q000503:physiopathology; D006801:Humans; D008323:Mammary Arteries / Q000503:physiopathology; D017534:Radial Artery / Q000503:physiopathology; D012501:Saphenous Vein / Q000503:physiopathology; D014654:Vascular Patency; D014655:Vascular Resistance