A new technique to create an artificial stenosis in the native LAD using a hemoclip

The study of hemodynamics associated with coronary atherosclerotic stenosis has been limited due to the lack of a safe, accurate, and reliable technique 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 developed a new technique to create an artificial stenosis in the native left anterior descending (LAD) coronary artery using a hemoclip in an experimental 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 application 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% were created in the LAD. Postoperative angiography demonstrated only 5-10% error between the true (angiography) and estimated (hemoclip technique) stenosis values. In all cases, the vessel remained intact without any apparent external trauma, and no indications of MI were present during electrocardiograph (ECG) monitoring. The creation of an artificial coronary stenosis using the hemoclip technique was safe, reliable, easy, and accurate.