title: Graft flow assessment using a transit time flow meter in fractional flow reserve-guided coronary artery bypass surgery.
abstract: OBJECTIVE
  To evaluate the relationship between preoperative severity of coronary stenosis occurring with fractional flow reserve (FFR), and the intraoperative bypass graft flow pattern.
  
  
  METHODS
  In all, 72 patients were enrolled in this retrospective study. The FFR value of the left anterior descending artery was evaluated, and data on "in situ" bypass grafting from the internal thoracic artery to the left anterior descending artery were assessed. Patients were divided into 3 groups according to preoperative FFR values (Group S: FFR < 0.70; group M: 0.70 ≤ FFR < 0.75; and group N: FFR ≥ 0.75).
  
  
  RESULTS
  In groups S, M, and N, respectively, mean graft flow was 24.7 ± 10.6 mL/minute, 19.2 ± 14.0 mL/minute, and 16.0 ± 9.7 mL mL/minute; pulsatility index was 2.35 ± 0.6, 3.02 ± 1.1, and 5.51 ± 8.20; and number of patients with systolic reverse flow was 3 (6.8%), 5 (35.7%), and 4 (28.6%). Significant differences were observed in graft flow (P = .009), pulsatility index (P = .038), and proportion of systolic reverse flow (P = .023) among the 3 groups. In all patients, graft patency was confirmed with intraoperative fluorescence imaging; postoperative graft patency was confirmed with multislice computed tomography or coronary angiography in 69 patients (follow-up interval: 213 days). Early graft failure occurred in 1 patient.
  
  
  CONCLUSIONS
  As coronary stenosis severity increased, graft flow increased, pulsatility index decreased, and proportion of patients with systolic reverse flow increased. In mild coronary artery stenosis, the chance of flow competition between the native coronary artery and the bypass graft increased.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan. Electronic address: honda-k@wakayama-med.ac.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Honda
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Okamura
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nishimura
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Uchita
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Yuzaki
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneko
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wakayama Medical University, Wakayama, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Department of Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Department of Cardiovascular Medicine, Wakayama Medical University, Wakayama, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D017023:Coronary Angiography / Q000379:methods; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D023921:Coronary Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D003331:Coronary Vessels / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000379:methods; D061330:Multidetector Computed Tomography; D061848:Optical Imaging; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency
keywords: FFR-guided coronary surgery; TTFM