Coronary angioscopy during cardiac catheterization

Coronary angioscopy should permit direct inspection of the luminal cross section and identification of disease. The feasibility of introducing a 5F Olympus Ultrathin fiberscope into the obstructed right coronary artery in five patients after routine cardiac catheterization by the brachial approach was therefore tested. An 8.3F USCI woven Dacron angioplasty guiding catheter was modified to enlarge its lumen. After engaging the right coronary ostium with the catheter, an attempt was made to pass the angioscope coaxially to the tip of the catheter. Visualization of the coronary lumen was then achieved in three patients by manually injecting 5 to 10 cc of normal saline solution through the guiding catheter at 2 to 3 cc/s. White atheromatous plaque could be seen near the site of obstruction in each case. In two patients, a lack of sufficient flexibility in the distal 2 cm of the angioscope prevented passage to the catheter tip. Preliminary experience with a videoendoscopic system suggests that this monitoring technique is essential for the adequate performance of angioscopy and for recording dynamic changes during blood displacement. Geometric distortion of the image and nonlinearities in magnification and light reflex with a decreasing lens to object distance make quantitative evaluation of the lumen difficult. Lack of an angulation system further contributes to this problem and, more importantly, restricts passage of the angioscope to the proximal 1 to 2 cm segments of coronary arteries. Although coronary angioscopy may have research and clinical applications in the future, these technical problems should first be addressed.