Angiographic Appearance of Patent Saphenous Vein Grafts After a Quarter-century Following Coronary Artery Bypass Surgery
Kazuo Tanemoto MD, PhD, Hiroshi Furukawa MD, PhD, Takeshi Honda MD, Takahiko Yamasawa MD, PhD
Department of Cardiovascular Surgery, Kawasaki Medical School, Kurashiki, Japan
Background: Saphenous vein graft is widely utilized graft material and keeps it position as an important option as graft conduit in CABG surgery. Its biggest problem is the limited long term patency compared with internal thoracic arteries; however, after some demonstrate perfect patency decades after surgery. We reviewed cases with angiographically patent saphenous vein grafts after a quarter-century following surgery.
Methods: Among 300 coronary artery bypass cases using SVG performed at Kawasaki Medical School between 1976 thorough 1991, we found ten cases with angiographically patent saphenous vein grafts over twenty-five years after surgery.
Results: The age at the time of surgery was 48.5 ± 6.0 (37~56), and sex distribution was eleven males and one female. Duration between the surgery and the last angiography, either by direct angiography (nine cases) or CT angiography (one case), was 29.4 ± 3.2 (25-35) years. The total number of the reviewed saphenous vein grafts was 11; 1.1 (1~2) per case. There were only two perfectly patent saphenous vein grafts (Fitzgibbon AI) (35 and 32 years after surgery), both of which were bypass grafts to the left anterior descending arteries (Figure). The other nine grafts had some vein graft disease (BII:2, BIII:6) and four grafts already had a history of catheter intervention. In one case with two patent grafts, one graft to the anterior descending artery exhibited perfect patency, but another one to the obtuse marginal artery had some stenotic lesions at the mid-body of the graft (BII). The two male patients with perfectly patent grafts were 46 and 45 years old at the time of surgeries, with a BMI of 22.90 and 18.44, respectively, and did not smoke after surgery. Both patients continued the drug therapy for diabetes, hyperlipidemia and hypertension, and treatment with antiplatelet agents.
Discussion: Although the saphenous vein graft has the limited patency as its biggest problem, some special treatments, such as no-touch harvest and external support have been introduced for improving the long-term patency. In our series, there were only two perfectly patent SVGs (case 2 and case 4) demonstrated over 30 years after surgeries. Both grafts were bypassed to LAD with good run-off. Interestingly, case2 had one more patent SVG to LCX, but the second patent SVG was severely diseased. Therefore, high graft flow by good run-off of the recipient artery may contribute to the slow progression of vein graft diseases. Moreover, the characteristics of those two patients contain non-smoking after surgery and non-obese at the last follow up. There are some possibilities that smoking and obesity after surgeries may affect the long-term patency of the SVG.
Conclusions: Among eleven angiographically patent saphenous vein grafts reviewed, only two grafts demonstrated perfect patency. Both of them were bypass grafts to the left anterior descending arteries with good run-off. High graft flow, which was maintained by the quality and run-off of the recipient artery, may contribute to the slow progression of vein graft diseases.