title: New approach to patency and flow assessment after left internal thoracic artery hypoperfusion syndrome with additional saphenous vein graft to the left anterior descending artery with phase-contrast magnetic resonance angiography.
abstract: OBJECTIVE
  Perioperative and early postoperative flow reduction of a left internal thoracic artery conduit is a rare complication of myocardial revascularization and may lead to the potentially fatal left internal thoracic artery hypoperfusion syndrome. It has been advocated that an additional vein graft be placed to the distal left anterior descending artery to provide sufficient myocardial perfusion. Some evidence exists, however, that this high-flow vein might lead to competing or even backward flow through the internal thoracic artery.
  
  
  METHODS
  In the past 2 years, 21 patients received an additional vein graft to the distal left anterior descending artery for left internal thoracic artery hypoperfusion syndrome. Nineteen of these patients were available for magnetic resonance imaging. Early (< 6 months) and late (> 12 months) postoperative flow measurements, both in the left internal thoracic artery and in the saphenous vein grafts, were performed by means of conventional and a segmented k-space phase-contrast magnetic resonance angiography technique.
  
  
  RESULTS
  Early magnetic resonance examinations indicated that all conduits had adapted to the coronary flow type with predominant diastolic perfusion. Patency rate both at the early and at the late study was 100%. No concurrent flow, flow reversal, or steal phenomena were observed. Mean flow rates were 49.2 ml/min for the left internal thoracic artery and 72.6 ml/min for the saphenous vein graft.
  
  
  CONCLUSIONS
  On the basis of the flow data obtained with magnetic resonance angiography, the use of an additional saphenous vein graft as the treatment of choice in left internal thoracic artery hypoperfusion syndrome does not lead to occlusion of the artery. Conduit flow adaptation to the diastolic predominance occurs in the first 6 months after operation.
authors.affiliation: Clinic for Cardio-vascular Surgery, Department of Medical Radiology, Zurich, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Zünd
authors.forename: M
authors.initials: M
authors.lastname: Hauser
authors.forename: P
authors.initials: P
authors.lastname: Vogt
authors.forename: C P
authors.initials: CP
authors.lastname: Davis
authors.forename: M
authors.initials: M
authors.lastname: Lachat
authors.forename: A
authors.initials: A
authors.lastname: Künzli
authors.forename: M
authors.initials: M
authors.lastname: Genoni
authors.forename: M
authors.initials: M
authors.lastname: Turina
mesh_terms: D003331:Coronary Vessels / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000517:prevention & control / Q000601:surgery; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D012501:Saphenous Vein / Q000637:transplantation*; D013997:Time Factors