In recent years, the right gastroepiploic artery has been attracting attention as a second reliable arterial graft for clinical application. In this study we measured the postoperative graft diameter of the right gastroepiploic artery and demonstrated the postoperative ''thinning down'' phenomenon of the right gastroepiploic artery graft. We report on coronary revascularization with the right gastroepiploic artery in 55 cases from December 1989 to July 1991. The properties of right gastroepiploic artery grafts were comparatively examined with the use of postoperative angiographic findings when possible. The results revealed that the patency ratio of right gastroepiploic artery grafts was satisfactory, with an average diameter of 2.1 mm (range 1.2 to 3.5 mm). ''String sign'' was not observed in these cases, but thinning down was noted in four cases. The thinning down phenomenon of the right gastroepiploic artery had previously been defined as a graft diameter no greater than that of a 5F catheter, with ineffective graft flow; it was termed slender sign. The development of slender sign is caused by good native coronary flow, narrowing of the perfused region, and poor runoff. Three cases of slender sign caused by good native flow had no signs of ischemia in the perfused regions, which was indicative of sufficient blood supply to the myocardium. The long-term patency ratio of right gastroepiploic artery grafts should be evaluated further.
