Editorial Comment
Long-Term Evaluation ofVein Bypass Grafts:Lessons to be Learned
David A. Clark, MD
Stanford University Medical CenterStanford, California
In this issue, van Brussel et al. [1] present a thoughtful article onthe effects of time and other factors on the progression ofatherosclerotic disease in bypassed native coronary arteries, and ofthe appearance and progression of disease in saphenous veinbypass grafts. Previous articles have indicated that the placement ofa vein bypass graft to a coronary artery accelerates the progressionof proximal disease. This article examines what happens to thedistal native vessel beyond the anastomosis of the bypass. Notsurprisingly, lesions in the coronary artery distal to the bypasscontinue to progress at the same rate as non-bypassed vessels in thesame patient; therefore, the bypass does not appear to retard oraccelerate the disease process in distal vessels.Vein bypasses do fail, with a 20%–30% occlusion rate in the first
year, thought to be due to technical failure or thrombosis. Thereaf-ter follows a ‘‘honeymoon’’ period of 5 or 6 years during whichrelatively few problems exist. Late narrowing of the bypass,whether by intimal hyperplasia or atherosclerosis, then occurs at anaccelerated rate such that at an average of 10 years post bypass35%–40% of open grafts show significant narrowing.Although long-term follow-ups of the use of radial and brachial
arteries as bypass conduits have not been demonstrated, the earlyresults are quite encouraging, and we hope that results will parallelthe excellent long-term patency rates with the use of the internalmammary artery as a bypass conduit.The following lessons can be learned:1) Vein bypasses continue to have a significant early and late
attrition rate, which should be understood by patients considering
alternative forms of therapy, such as medical treatment or angio-plasty. Many patients initially view bypass surgery as a curativeprocedure, but as the current and previous articles clearly indicate,bypassing coronary arteries is palliative but not a cure foratherosclerotic disease.2) It would appear that the long-term patency of vessels treated
with angioplasty is better than the patency of vein bypass grafts.Patients should be educated that, once beyond the 6-monthrecurrence time, angioplasty may be a superior long-term solutionto the anatomic problem.3) The early graft failure rate mandates that one of the most
important aspects of graft success remains the quality of surgery.As small cardiovascular programs spring up with inexperiencedand underutilized surgeons, technical expertise remains a criticalissue in the success of the revascularization procedure.4) At the current time, it would seem wise to encourage
surgeons to use the internal mammary, radial, and brachial arteriesas bypass conduits at least until long-term follow-up is available.Hopefully, results will parallel the excellent internal mammarystatistics.5) Aggressive efforts to lower cholesterol and lipids have shown
a positive effect on both graft patency and the progression ofdisease in native coronary arteries. A strong effort to encouragepatients to modify their risk profile, particularly with smokingcessation and lipid reduction, would be part of the post-revascularization treatment program.Some patients may continue to view interventional or surgical
procedures as a ticket to an uninhibited lifestyle, but it is incumbentupon the cardiologist to gently shatter that notion (without unduepessimism) and to encourage appropriate risk factor modification.
REFERENCES
1. van Brussel BL, Plokker HWT, VoorsAA, Ernst SMPG, Kelder HC:Progression of atherosclerosis after venous coronary artery bypassgraft surgery: A 15-year follow-up study. Cathet Cardiovasc Diagn41:141–150, 1997.
Catheterization and Cardiovascular Diagnosis 41:151 (1997)
r 1997 Wiley-Liss, Inc.
