IN VIVO TESTS OF THE HALLIBURTON ENDARTERECTOMY CATHETER
To date the Halliburton atherectomy catheter has been successfully introduced into the aorta of 10 normal White Leghorn roosters. During a pilot study with the atherectomy prototype in the first two birds the atherectomy catheter was introduced successfully, but the outer percutaneous sheath initially used to enter the femoral artery in the roosters’ legs allowed a great deal of blood loss and the roosters died after two days. Once this problem was solved, the next eight trials were all successful. It should be noted, however, that even in the first two roosters studied, there was no evidence of catheter induced arterial damage or perforation.
The first eight roosters to complete atherectomies are undergoing follow-up angiographic examination and histologic examination at selected time intervals. No immediate adverse effects of atherectomy have been demonstrated. There was no inadvertent removal of normal arterial intima when the atherectomy catheter was operated in the rooster aorta. The immediate repeat aortograms, post-intervention, demonstrate no intimal tear, spasm, or occlusion. Figures 3A-C show representative contrast aortography recorded during insertion of the Halliburton atherectomy catheter into the aorta of a normal rooster. Although the long-term results are pending, the first three follow-up cases showed no gross or angiographic evidence of early restenosis.
After each rooster had balloon angioplasty of the abdominal aorta in order to produce atheromata, the femoral artery used for vascular access was tied off. In all cases at follow-up there was occlusion and stenosis at the site where the sheath and the various catheters and balloons were introduced. We have used the Halliburton catheter in one of these occluded femoral arteries. In the first successful attempt plaque was excised and the internal diameter of the femoral artery was increased. There was an intimal dissection, but the diameter and arterial flow were 3% to 40% improved.