Historical Rates of Saphenous Vein Graft Failure
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Definition of SVG Failure
Saphenous vein graft occlusion is defined as a complete, 100% occlusion of a saphenous vein graft. [1]
Saphenous vein failure is defined as an occlusion of the vein graft or a 75% or greater stenosis.
Per Patient and Per Lesion Analyses of SVG Failure
The rate of occlusion or failure of saphenous vein grafts is calculated on a per graft basis and a per patient basis. The per patient basis is higher, because only one vein graft out of several must fail for the patient to be characterized as a failure. Analyses should be presented on both a per patient basis (the unit of randomization) and a per SVG basis (the unit that is associated with clinical events). Because the behavior of multiple SVGs may be correlated, and this within patient correlation may reduce the estimate of the variance in the population, an adjustment for the within patient correlation must be provided when presenting the results on a per SVG basis[2]. The within patient conocrdance can be adjusted for using a General Linear Model of Intraclass Correlation (GLIMIC) [2].
Historical Rates of SVG Failure and Occlusion
Current rates of graft occlusion and failure are as follows:[1] The rate of per patient vein graft occlusion at 12-18 months is about 42%
The rate of per patient vein graft failure at 12-18 months is about 46%
The rate of per graft vein graft occlusion at 12-18 months is about 26%
The rate of per graft vein graft failure at 12-18 months is about 29%
As a comparison, the rate of internal mammary artery failure at 12-18 months was only 8%.
Underestimation of SVG Failure in Earlier Studies
These carefully ascertained current rates of occlusion are higher than what are often quoted in the literature which were [3]:
- 15% rate of SVG occlusion at 1 year
- 25% rate of SVG occlusion at 6 years
- 40% rate of SVG occlusion at 10 years
Potential for Pre-Operative SVG Failure
It should be noted that studies of SVGs that are not implanted show that about 1% of veins are already stenosed by > 50% before implantation[4].
References
- ↑ 1.0 1.1 Alexander JH, Hafley G, Harrington RA, Peterson ED, Ferguson TB, Lorenz TJ, Goyal A, Gibson M, Mack MJ, Gennevois D, Califf RM, Kouchoukos NT (2005). "Efficacy and safety of edifoligide, an E2F transcription factor decoy, for prevention of vein graft failure following coronary artery bypass graft surgery: PREVENT IV: a randomized controlled trial". JAMA : the Journal of the American Medical Association. 294 (19): 2446–54. doi:10.1001/jama.294.19.2446. PMID 16287955. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ 2.0 2.1 Gibson CM, Kuntz RE, Nobuyoshi M, Rosner B, Baim DS (1993). "Lesion-to-lesion independence of restenosis after treatment by conventional angioplasty, stenting, or directional atherectomy. Validation of lesion-based restenosis analysis". Circulation. 87 (4): 1123–9. PMID 8462141. Retrieved 2010-10-31. Unknown parameter
|month=ignored (help) - ↑ Motwani JG, Topol EJ. Aortocoronary saphenous vein graft disease: pathogenesis, predisposition, and prevention. Circulation 1998;97:916-31.
- ↑ Waller BF, Roberts WC (1985). "Remnant saphenous veins after aortocoronary bypass grafting: analysis of 3,394 centimeters of unused vein from 402 patients". The American Journal of Cardiology. 55 (1): 65–71. PMID 3871302. Retrieved 2010-11-09. Unknown parameter
|month=ignored (help)