title: Preserved hyperaemic response in (distal) string sign left internal mammary artery grafts.
abstract: OBJECTIVE
  To correlate supraclavicular ultrasonography at rest and in hyperaemic response with angiographically patent and (distal) 'string sign' left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts.
  
  
  METHODS
  Fifty-three patients with LIMA to LAD area grafting were prospectively entered in a follow-up study. Arteriography (native and LIMA) was performed at 1.4+/-0.8 years postoperatively and ultrasonography was performed at rest, in hyperaemic response and 2min after hyperaemic response at 1.8+/-0.8 years postoperatively and was compared to arteriography. Ultrasonographic parameters analysed were systolic and diastolic peak velocity, systolic and diastolic velocity integral, diastolic/systolic peak velocity ratio and diastolic/total velocity integral ratio.
  
  
  RESULTS
  One patient was excluded because obesity hampered ultrasonography. Arteriography demonstrated functional grafts in 43 patients (group I), sequential distal 'string sign grafts' in 4 patients (group II) and total 'string sign grafts' in 5 patients (group III). Between the groups all ultrasonographic velocities showed a significant linear relation (p<or=0.013) at rest and during maximal hyperaemic response all velocities increased significantly within all groups (p<or=0.018). A significant decrease was found 2min after hyperaemic response and diastolic velocities showed a significant linear relation (p<or=0.032).
  
  
  CONCLUSIONS
  String sign LIMA grafts' were found in 9/52 (17.3%) patients. All patent and all 'string sign grafts' showed a shift towards a coronary flow profile in the proximal segment postoperatively. The study revealed the 'functionality' of the patent and the (distal) 'string sign LIMA graft' in regard to myocardial oxygen demand. 'String sign grafts' are 'recruitable' on demand.
authors.affiliation: Department of Cardiothoracic Surgery, Thoraxcentre, Bd 575, Erasmus Medical Centre Rotterdam, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Joost
authors.initials: J
authors.lastname: Hartman
authors.forename: Hans
authors.initials: H
authors.lastname: Kelder
authors.forename: Rob
authors.initials: R
authors.lastname: Ackerstaff
authors.forename: Henry
authors.initials: H
authors.lastname: van Swieten
authors.forename: Freddy
authors.initials: F
authors.lastname: Vermeulen
authors.forename: Ad
authors.initials: A
authors.lastname: Bogers
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D006940:Hyperemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D007387:Internal Mammary-Coronary Artery Anastomosis; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D014654:Vascular Patency