title: Factors affecting patency of internal thoracic artery graft: clinical and angiographic study in 1434 symptomatic patients operated between 1982 and 2002.
abstract: OBJECTIVE
  The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy.
  
  
  METHODS
  1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis.
  
  
  RESULTS
  96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years).
  
  
  CONCLUSIONS
  Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied.
authors.affiliation: Department of Cardiac Surgery, Austin Health, Studley Road, Heidelberg, Vic. 3084 Australia.
authors.forename: Pallav J
authors.initials: PJ
authors.lastname: Shah
authors.forename: Manoj
authors.initials: M
authors.lastname: Durairaj
authors.forename: Ian
authors.initials: I
authors.lastname: Gordon
authors.forename: John
authors.initials: J
authors.lastname: Fuller
authors.forename: Alex
authors.initials: A
authors.lastname: Rosalion
authors.forename: Siven
authors.initials: S
authors.lastname: Seevanayagam
authors.forename: James
authors.initials: J
authors.lastname: Tatoulis
authors.forename: Brian F
authors.initials: BF
authors.lastname: Buxton
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000379:methods*; D008297:Male; D008323:Mammary Arteries / Q000000981:diagnostic imaging; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014654:Vascular Patency