A 5F or 7F Sones catheter (USCI Division, CR Bard Inc, Billerica, Mass) was advanced through the left carotid artery into the left anterior descending coronary artery (LAD). A steerable guide wire (USCI) was then advanced under fluoroscopy through the Sones catheter into the proximal LAD. The Sones catheter was then removed, and a Gruentzig catheter (USCI; balloon size, 25.0 mm in length and 3.0 mm in diameter) was advanced over the guide wire into the LAD, as distally as possible. Angioplasty was performed with four balloon insufflations, 30 s each, with a 60-s interval; the first two were at 10 atm, and the last two were at 8 atm. The Sones catheter was then placed again into the proximal LAD and was flushed continuously with 0.9 percent NaCl solution, 0.3 ml/min, with heparin, 10 IU/ml. Arteriograms were obtained at 5, 15, 30, 60, and 120 min after angioplasty. Immediately after the last arteriogram, the dogs were killed with pentobarbital and KC1.
The dogs were placed in the right lateral decubitus position, and left anterior oblique images were recorded in order to optimize viewing of proximal/medial LAD segments. The dogs position was carefully maintained after the first baseline arteriographic study. In preliminary experiments, we verified that right anterior oblique viewing added little information in this model, because the LAD was nearly perpendicular to the screen. Coronary arteriograms were obtained through manual injection of 3 to 4 ml of a mixture of meglumine diatrizoate and sodium diatrizoate (Hypaque M-76%, Winthrop Products Inc, New York) and were recorded with unipla-nar dnephotofluorography (Super M-80 model, Philips Medical Systems, Eindhoven, Netherlands) at a rate of 30 frames per second with 35-mm Kodak PFC 746 film (Eastman Kodak Company, Rochester, NY).
The Role of Coronary Arteriography in Demonstration of Mural Thrombosis after Angioplasty (2)