The study of hemodynamics associated with coronary atherosclerotic stenosis
has been limited due to the lack of a safe, accurate, and reliable techniq
ue to create an artificial stenosis in an animal model. Existing techniques
have often resulted in myocardial infarction (MI) or severe injury to the
vessel and have been difficult to accurately quantify and reproduce. We dev
eloped a new technique to create an artificial stenosis in the native left
anterior descending (LAD) coronary artery using a hemoclip in an experiment
al off-pump coronary artery bypass graft (CABG) animal model that overcomes
these limitations. The native LAD was dissected at its proximal end and a
hemoclip was applied to create varying degrees of artificial stenosis in 30
mongrel dogs during experimental off-pump CABG procedures. The precise app
lication of the hemoclip was predetermined using a mathematical formula to
calculate the reduced circumference required to create a specific stenosis.
Using these calculations, artificial stenoses of 25%, 50%, 75%, and 90% we
re created in the LAD. Postoperative angiography demonstrated only 5-10% er
ror between the true (angiography) and estimated (hemoclip technique) steno
sis values. In all cases, the vessel remained intact without any apparent e
xternal trauma, and no indications of MI were present during electrocardiog
raph (ECG) monitoring. The creation of an artificial coronary stenosis usin
g the hemoclip technique was safe, reliable, easy, and accurate.