title: Intraoperative transit time flow measurement: off-pump versus on-pump coronary artery bypass.
abstract: BACKGROUND
  Off-pump coronary artery bypass grafting (OPCAB) has attracted increasing attention. Performing the anastomosis off-pump is technically more demanding. The objective of the study is to assess the quality of anastomosis in OPCAB in comparison with conventional on-pump coronary artery bypass grafting using the transit time flow measurement.
  
  
  METHODS
  Four hundred forty-five patients operated on using OPCAB technique were included in the study. For each patient in this group a similar patient from the on-pump coronary artery bypass grafting population was selected according to the number of grafts, bypass material, and target coronary arteries. The mean flow and the pulsatile index were measured in every bypass graft in both groups.
  
  
  RESULTS
  The average pulsatile index in OPCAB was 2.09 +/- 1.03 (mean flow, 39 +/- 22.63 mL/min), whereas with on-pump coronary artery bypass grafting it was 1.9 +/- 0.98 (mean flow, 44.19 +/- 23.58 mL/min); p = 0.005. Subgroup analysis showed significantly lower mean flows and higher pulsatile index with OPCAB in grafts to the obtuse marginal, diagonal, and right coronary artery, but not to the left anterior descending territory.
  
  
  CONCLUSIONS
  The quality of the anastomosis performed using the OPCAB technique might be jeopardized by less accessibility as in the case of lateral and posterior wall coronary arteries. Techniques to optimize the accessibility of the coronary artery like combining sling support with cup stabilizers, together with systematic training, should be strongly considered in OPCAB. Whenever there is good accessibility of the coronary artery as in the case of the left anterior descending, the anastomosis performed under OPCAB has a quality as good as that performed using the conventional technique.
authors.affiliation: Clinic for Cardiothoracic Surgery, Heart Institute Lahr/Baden, Lahr, Germany.
authors.forename: Wael
authors.initials: W
authors.lastname: Hassanein
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Albert
authors.forename: Bert
authors.initials: B
authors.lastname: Arnrich
authors.forename: Joerg
authors.initials: J
authors.lastname: Walter
authors.forename: Ina Carolin
authors.initials: IC
authors.lastname: Ennker
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rosendahl
authors.forename: Stefan
authors.initials: S
authors.lastname: Bauer
authors.forename: Juergen
authors.initials: J
authors.lastname: Ennker
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass; D047549:Coronary Artery Bypass, Off-Pump; D003326:Coronary Circulation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D013997:Time Factors