Intraoperative detection of intimal lipid in the radial artery predicts degree of postoperative spasm



      The radial artery's (RA) tendency to spasm when used as a bypass graft may relate to features of the RA itself. We imaged RA conduits before and after CABG in order to characterize intimal abnormalities that might relate to the risk of spasm.


      RA conduits from thirty-two CABG patients were imaged intraoperatively using catheter-based optical coherence tomography (OCT) and again on day 5 using 64-channel MDCT angiography. The change in luminal diameter between timepoints was measured in the proximal, mid and distal RA. “Spasm” was defined as focal or diffuse luminal narrowing to a diameter less than the target coronary. Lipid content in the RA was quantified by the degree of light attenuation on the OCT image.


      Postoperative spasm was diagnosed in 18 of 32 (56%) RA grafts with the distal RA showing the most severe change versus the mid and proximal portions (−24.1 ± 43.2% vs. −15.3 ± 40.7%, −9.0 ± 42.5% change in diameter respectively, p < 0.01). The degree of attenuation of the OCT signal produced by the RA was strongly correlated with % diameter change (R = 0.64, p = 0.0005) and was significantly more pronounced in grafts with spasm versus no spasm (−1.97 ± 0.61 mm−1 vs. −0.81 ± 0.57 mm−1, p < 0.0001). Histology confirmed lipid deposits in areas of RA with strong attenuation.


      RA conduits otherwise considered acceptable for bypass grafting were often found by OCT imaging to have a substantial amount of lipid, which in turn strongly relates to the risk of postoperative spasm. Screening conduits based on characteristics of intimal quality may improve results following RA grafting.


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        • Cameron A.
        • Davis K.B.
        • Green G.
        • Schaff H.V.
        Coronary bypass surgery with internal-thoracic-artery grafts—effects on survival over a 15-year period.
        N Eng J Med. 1996; 334: 216-219
        • Desai N.D.
        • Cohen E.A.
        • Naylor C.D.
        • Fremes S.E.
        A randomized comparison of radial-artery and saphenous-vein coronary bypass grafts.
        N Eng J Med. 2004; 351: 2302-2309
        • Kaufer E.
        • Factor S.M.
        • Frame R.
        • Brodman R.F.
        Pathology of the radial and internal thoracic arteries used as coronary artery bypass grafts.
        Ann Thorac Surg. 1997; 63: 1118-1122
        • Zhang Y.
        • Janssen L.
        • Chu F.V.
        Atherosclerosis of radial arterial graft may increase the potential of vessel spasm in coronary bypass surgery.
        J Thorac Cardiovasc Surg. 2005; 130: 1477-1478
        • Desai N.D.
        • Naylor C.D.
        • Kiss A.
        • et al.
        Impact of patient and target-vessel characteristics on arterial and venous bypass graft patency: insight from a randomized trial.
        Circulation. 2007; 115: 684-691
        • Brown E.N.
        • Burris N.S.
        • Gu J.
        • et al.
        Thinking inside the graft: applications of optical coherence tomography in coronary artery bypass grafting.
        J Biomed Opt. 2007; 12: 051704
        • Brazio P.S.
        • Laird P.C.
        • Xu C.
        • et al.
        Scalpel versus electrocautery for harvest of radial artery conduits: reduced risk of spasm, intimal injury on optical coherence tomography.
        J Thorac Cardiovasc Surg. 2008; 136: 1302-1308
        • Xu C.
        • Schmitt J.M.
        • Carlier S.G.
        • Virmani R.
        Characterization of atherosclerosis plaques by measuring both backscattering and attenuation coefficients in optical coherence tomography.
        J Biomed Opt. 2008; 13: 034003
        • Ganz P.
        • Alexander R.W.
        New insights into the cellular mechanisms of vasospasm.
        Am J Cardiol. 1985; 56: 11-15E
        • Barbeau G.R.
        • Arsenault F.
        • Dugas L.
        • Simard S.
        • Lariviere M.M.
        Evaluation of the ulnopalmar arterial arches with pulse oximetry and plethysmography: comparison with the Allen's test in 1010 patients.
        Am Heart J. 2004; 147: 489-493
        • He G.W.
        • Rosenfeldt F.L.
        • Angus J.A.
        Pharmacological relaxation of the saphenous vein during harvesting for coronary artery bypass grafting.
        Ann Thorac Surg. 1993; 55: 1210-1217
        • Royse A.G.
        • Royse C.F.
        • Shah P.
        • et al.
        Radial artery harvest technique, use and functional outcome.
        Eur J Cardiothorac Surg. 1999; 15: 186-193
        • Bolotin G.
        • Kypson A.P.
        • Nifong L.W.
        • Chitwood W.R.
        A technique for evaluating competitive flow for intraoperative decision making in coronary artery surgery.
        Ann Thorac Surg. 2003; 76: 2118-2120
        • Kume T.
        • Akasaka T.
        • Kawamoto T.
        • et al.
        Assessment of coronary intima–media thickness by optical coherence tomography: comparison with intravascular ultrasound.
        Circ J. 2005; 69: 903-907
        • He G.W.
        Arterial grafts for coronary artery by pass grafting: biological characteristics functional classification and clinical choice.
        Ann Thorac Surg. 1999; 67: 277-284
        • FitzGibbon G.M.
        • Leach A.J.
        • Kafka H.P.
        • Keon W.J.
        Coronary bypass graft fate: long-term angiographic study.
        J Am Coll Cardiol. 1991; 17: 1075-1080
        • Hamon M.
        • Lepage O.
        • Malagutti P.
        • et al.
        Diagnostic performance of 16- and 64-section spiral CT for coronary artery bypass graft assessment: meta-analysis.
        Radiology. 2008; 247: 679-686
        • Gaudino M.
        • Nasso G.
        • Canosa C.
        • et al.
        Midterm angiographic patency and vasoreactive profile of proximal versus distal radial artery grafts.
        Ann Thorac Surg. 2005; 79: 1987-1989
        • Nakamura K.
        • Al-Ruzzeh S.
        • Chester A.H.
        • et al.
        Effects of cerivastatin on vascular function of human radial and left internal thoracic arteries.
        Ann Thorac Surg. 2002; 73 ([discussion 1865]): 1860-1865
        • Hayashi T.
        • Ishikawa T.
        • Naito M.
        • et al.
        Low level hyperlipidemia impairs endothelium-dependent relaxation of porcine coronary arteries by two mechanisms. Functional change in endothelium and impairment of endothelium-dependent relaxation by two mediators.
        Atherosclerosis. 1991; 87: 23-38
        • Fujimoto J.G.
        • Boppart S.A.
        • Tearney G.J.
        • et al.
        High resolution in vivo intra-arterial imaging with optical coherence tomography.
        Heart. 1999; 82: 128-133
        • Ruengsakulrach P.
        • Brooks M.
        • Sinclair R.
        • et al.
        Prevalence and prediction of calcification and plaques in radial artery grafts by ultrasound.
        J Thorac Cardiovasc Surg. 2001; 122: 398-399
        • Burris N.
        • Schwartz K.
        • Tang C.M.
        • et al.
        Catheter-based infrared light scanner as a tool to assess conduit quality in coronary artery bypass surgery.
        J Thorac Cardiovasc Surg. 2007; 133: 419-427
        • Merlo M.
        • Terzi A.
        • Tespili M.
        • Ferrazzi P.
        Reversal of radial artery ‘string sign’ at 6 months follow-up.
        Eur J Cardiothorac Surg. 2003; 23: 432-434
        • Lamping K.G.
        Enhanced contractile mechanisms in vasospasm: is endothelial dysfunction the whole story?.
        Circulation. 2002; 105: 1520-1522