The Annals of Thoracic Surgery, Vol 50, 360-366, Copyright © 1990 by The Society of Thoracic Surgeons
Flow capacity of the human retrograde internal mammary artery: surgical considerations
JM Gonzalez-Santos, E Bastida, M Riesgo, JL Vallejo, JV Albertos, R Fortuny and R Arcas
Department of Cardiovascular Surgery, Hospital General Gregorio Maranon, Universidad Complutense, Madrid, Spain.
The diastolic flow of the retrograde internal mammary artery (IMA) was
calculated in 30 patients and compared with the expected coronary flow of
the left ventricle and that of specific branches. Arterial pressure and
free flow were measured in the proximal and distal IMA as well as in the
superior epigastric and musculophrenic arteries. Systolic and mean arterial
pressure were significantly higher in the proximal IMA than in any other
site, but diastolic pressure was comparable. Overall and diastolic
antegrade IMA flows (77 +/- 6 and 44 +/- 3 mL/min) were significantly
greater than the retrograde flows through the distal IMA (18.5 +/- 2 and
11.5 +/- 1 mL/min), musculophrenic artery (13.3 +/- 1 and 7.9 +/- 1
mL/min), and superior epigastric artery (5.3 +/- 0.4 and 3.1 +/- 0.2
mL/min). Only patient-size-related variables correlated significantly with
retrograde IMA flow. Diastolic retrograde IMA flow represented 8.5% +/-
0.6% of the expected left ventricle coronary flow and in 12 patients (40%)
was greater than the expected flow of at least one posteroinferior coronary
artery. Based on these data, the retrograde IMA may adequately perfuse the
posterior descending or other posterolateral coronary branches in select
patients. Previous measuring of the retrograde flow is mandatory.
