INTERVENTION IN PERIPHERAL VASCULAR DISEASE

The First Clinical Experience with a Peripheral, Self-Expanding Nitinol Stent in the Treatment of Saphenous Vein Graft Disease:

*Syed W. Bokhari, MD, *Omid Vahdat, MD, *†Rex J. Winters, MD
*Syed W. Bokhari, MD, *Omid Vahdat, MD, *†Rex J. Winters, MD
Coronary artery bypass graft surgery (CABG) is an established form of revascularization, typically associated with improved survival. However, CABG has its own inherent deficiencies, including recurrent ischemia, venous graft failure and the need for repeat revascularization. The ideal treatment for degenerated vein grafts is controversial. Treatment options for saphenous vein graft (SVG) disease are repeat CABG and percutaneous coronary intervention (PCI) using balloon and non-balloon technologies. Currently, a number of non-balloon interventional devices are available for use in SVG disease. Atherectomy catheters, thrombectomy devices, thrombolysis and distal embolic protection systems all have proven efficacy compared to balloon angioplasty in the treatment of SVG disease. However, a minority of patients are not candidates for the above-mentioned standard forms of treatment due to the location of the disease or the size of the SVG. In addition, there still exist a number of serious potential complications of percutaneous transluminal coronary angioplasty (PTCA), including distal embolization, no reflow phenomenon, abrupt closure and in-stent restenosis. We report the first case of a patient with symptomatic SVG disease treated successfully with a peripheral, self-expanding nitinol stent without any acute or long-term complications, as well as evidence of late expansion upon follow-up angiography. The case report is followed by a review of the literature on stenting for SVG disease. Case Report. A 68-year-old male with a history of CABG presented with an acute coronary syndrome. He had undergone 3 CABG surgeries previously, the most recent in 1995. His other past medical history was significant for diet-controlled diabetes mellitus, hypertension, dyslipidemia, sick sinus syndrome, gout, chronic obstructive pulmonary disease and chronic renal insufficiency. The patient underwent cardiac catheterization after informed consent was obtained. He received peri-procedural saline hydration and N-acetylcysteine administration. He was also pre-treated with eptifibatide (glycoprotein IIb/IIIa receptor inhibitor) in adjunct to aspirin, plavix and heparin for maximal antiplatelet protection. Cardiac catheterization revealed a 30% disease in the distal left main artery. The left anterior descending (LAD) artery demonstrated a 100% stenosis after giving off a small septal perforator and diagonal branches. The left circumflex artery was diffusely diseased with 50% proximal and 100% mid lesions. The dominant right coronary artery had 50% proximal and 100% mid stenoses. The SVG to the posterior descending artery (PDA) showed a long 60–70% stenotic lesion. The SVGs to the LAD and the first diagonal branch were found to be patent without any significant disease. The SVG to the first obtuse marginal branch (OM) of the left circumflex artery with a jump to the second OM branch had a high-grade 82% diameter stenosis by quantitative coronary analysis (QCA) in the mid-portion with a TIMI grade I flow distally and was deemed to be the culprit vessel (Figure 1). Excimer laser coronary atherectomy (ELCA) was performed on the SVG to the OM branches of the left bok-1c.jpgbok-1d.jpgbok-1e.jpgbok-1f.jpgbok-2a.jpgbok-2b.jpgbok-2c.jpgbok-2d.jpgbokfig3.jpgbokfig4.jpg**Conclusion. We report the first case of a peripheral, self-expanding nitinol stent used in the treatment of symptomatic SVG disease. The patient tolerated the procedure well, without any short- or long-term complications, and did well clinically during the follow-up. We have also shown the angiographic evidence of the late expansion of the nitinol stent regardless of whether the stent underwent post-dilatation with a balloon. Treatment of symptomatic SVG disease with a peripheral, self-expanding nitinol stent seems technically feasible and safe, and promises long-term patency. Late expansion of the nitinol stent regardless of post-dilatation may help avoid distal embolization and result in less neointimal formation, suggesting direct stenting of the SVG lesions with a favorable outcome. Questions arise about whether the self-expanding nitinol stents should be used alone or in adjunct to other strategies to treat old, degenerated vein grafts, and whether post-dilatation with a balloon should be performed for further expansion of the self-expanding stent given the potential risks of distal embolization and no reflow. Larger-scale trials are warranted to evaluate the use, safety and efficacy of the self-expandable nitinol stents in SVG disease. Acknowledgment. We are grateful to David P. Faxon, MD, FACC, Chief of the Division of Cardiology, University of Chicago-School of Medicine for reviewing and editing the manuscript as well as providing his invaluable input. We are also thankful to Derek Lester, RT (R), Manager of the Cardiac Catheterization Laboratory at Long Beach Memorial Medical Center, for helping with the preparation of the manuscript.
References
1. Chen L, Theroux P, Lesperance J, et al. Angiographic features of vein grafts versus ungrafted arteries in patients with unstable angina and previous bypass surgery. J Am Coll Cardiol 1996;28:1493–1499. 2. Motwani JG, Topol EJ. Aortocoronary saphenous vein graft disease pathogenesis, predispositions and prevention. Circulation 1998;97:916–931. 3. Savage MP, Douglas JS Jr., Fischman DL, et al. Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators. N Engl J Med 1997;337:740–747. 4. Safian RD, Kaplan B, Schreiber T, et al. Final results of the randomized Wallstent endoprosthesis in saphenous vein graft trial (WINS). J Am Coll Cardiol 1999;33:37A. 5. Dechene HA, Radke PW, Schwarz ER, et al. Acute and 6-month long-term results with an endoluminal polytetrafluoroethylene stent graft in patients with in-stent restenosis and venous coronary artery bypass grafts. Am J Cardiol 1999;84(Suppl 6A):12P. 6. Baldus S, Koster R, Reimers J, Hamm CW. Membrane-covered stents for the treatment of aortocoronary vein graft disease. Cathet Cardiovasc Intervent 2000;50:83–88. 7. Duprat G Jr., Wright KC, Charnasangavej C, et al. Self-expanding metallic stents for small vessels: An experimental evaluation. Radiology 1987;162:469–472. 8. Rollins N, Wright KC, Charnasangavej C, et al. Self-expanding metallic stents: Preliminary evaluation in an atherosclerotic model. Radiology 1987;163:739–742. 9. Jedwab MR, Clerc CO. A study of the geometrical and mechanical properties of a self-expanding metallic stent — Theory and experiment. J Appl Biomater 1993:4:77–85. 10. Hong MK, Beyar R, Kornowski R, et al. Acute and chronic effects of self-expanding nitinol stents in porcine coronary arteries. Coron Artery Dis 1997;8:45–48. 11. Carter AJ, Scott D, Laird JR, et al. Progressive vascular remodeling and reduced neointimal formation after placement of a thermoelastic self-expanding nitinol stent in an experimental model. Cathet Cardiovasc Diagn 1998;44:193–201. 12. Henry M, Amor M, Beyar R, et al. Clinical experience with a new nitinol self-expanding stent in peripheral arteries. J Endovasc Surg 1996;3:369–379. 13. Verheye S, Salame MY, Robinson KA, et al. Short- and long-term histopathologic evaluation of stenting using a self-expanding nitinol stent in pig carotid and iliac arteries. Cathet Cardiovasc Intervent 1999;48:316–323. 14. Roguin A, Grenadier E, Linn S, et al. Continued expansion of the nitinol self-expanding coronary stent: Angiographic analysis and 1-year clinical follow-up. Am Heart J 1999;138:326–333. 15. Han R, Schwartz RS, Kobayashi Y, et al., for the Stent Comparative REStenosis (SCORES) Trial Investigators. Comparison of self-expanding and balloon-expandable stents for the reduction of restenosis. Coron Artery Dis 2001;88:253–259. 16. Virmani R. Editorial comment: Self-expanding stent deployment strategies may be the key to reducing in-stent restenosis. Cathet Cardiovasc Intervent 2002;56:487–488. 17. Konig A, Schiele TM, Rieber J, et al. Stent design-related coronary artery remodeling and patterns of neointima formation following self-expanding and balloon-expandable stent implantation. Cathet Cardiovasc Intervent 2002;56;478–486.