Flow dynamics in internal thoracic artery grafts 10 years after coronary artery bypass grafting.
BACKGROUND
Flow dynamics in internal thoracic artery grafts 10 years after surgery are not known.


METHODS
Doppler examination was performed in native internal thoracic arteries as a control (n = 8) and in internal thoracic artery grafts to the left anterior descending coronary artery 6 months postoperatively (group A, n = 25), at 5 years (group B, n = 14), and at 10 years (group C, n = 11).


RESULTS
Each graft group showed a diastolic to systolic peak velocity ratio of less than 1.0 at the proximal end, and more than 1.0 at the distal end, but the control group showed a ratio of less than 1.0 throughout the length of the artery. The diastolic peak velocity of the graft groups was significantly faster than that of the control group at the distal end (versus group A, p < 0.01; versus group B, p < 0.005; and versus group C, p < 0.05). The systolic peak velocity of the graft groups was significantly lower than that of the control at the proximal end (versus group A, p < 0.0001; versus group B, p < 0.005; and versus group C, p < 0.0005). There were no significant differences of flow velocities among the graft groups and graft diameter among the four groups.


CONCLUSIONS
Although the internal thoracic artery is systolic predominant, when native artery is used as graft, it changes its hemodynamics to diastolic predominance, especially at the distal end. Even after 10 years, graft flow dynamics are unchanged. This hemodynamic character may be one of the factors related to the superior long-term patency.
Ichikawa
Yukio
Y
First Department of Surgery, Yokohama City University School of Medicine, Yokohama, Japan.
Kajiwara
Hirokazu
H
Noishiki
Yasuharu
Y
Yamazaki
Ichiya
I
Yamamoto
Kenji
K
Kosuge
Takayuki
T
Sato
Sunao
S
Takanashi
Yoshinori
Y
D000787:Angina Pectoris / Q000503:physiopathology / Q000601:surgery; D001013:Aorta, Thoracic / Q000502:physiology / Q000637:transplantation*; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass; D015150:Echocardiography, Doppler; D018056:Hemorheology; D006801:Humans; D011184:Postoperative Period; D014654:Vascular Patency / Q000502:physiology