Progress in cardioangioscopy.

IN 1925, Dr. Kussmal in Germany constructed a device with a metallic tube containing a lens inside for observation of the interior of stomach. This was the first clinical use of an endoluminal scope (endoscope). However, since it was rigid, it was a great burden on the patient to have it introduced through the mouth into the stomach. On August 31, 1945, a big storm attacked Tokyo and surrounding areas (Kanto region) of Japan. Trains were stopped for several hours due to the storm and Dr. Toru Uji, a surgeon at Tokyo University and Mr. Masao Sugiura of Olympus Optical happened to meet on the train and discuss the concept of a new endoscope. This was the start of development of the endoscope in Japan. In December, 1949, in corrabolation with Mitsuya Fukaomi and Mamoru Maruyama of Olympus Optical, they developed a flexible gastroscope 12 mm in diameter equipped with film and an illumination source in the distal most tip. Anesthetized dogs were successfully examined with this endoscope. Tetsuya Sakamoto of Tokyo University used this endoscope for the first time as a gastroscope. The flexible gastroscope thus developed has served as the basic structure for the bronchoscope, cystoscope and other types of similar scopes. Several years later, this gastroscope was replaced by a fiberscope which was more flexible and more easy to manipulate. Fiberscopes are now widely used as an essential tool to diagnose and treat not only the digestive tract but also the respiratory and urogenital tracts. Although the endoscope was used clinically in peripheral arteries during surgery by Dr. SM Greenstone, many years elapsed until percutaneous transluminal coronary angioscopy was performed. This was due to difficulties related to the displacement of blood in the artery and the need for a more flexible and thinner endoscope. In anticipation of clinical applications, we (the author and members of Olympus Optical) began to develop a new fiberscope for coronary use