Coronary Bypass Grafting for Single-Vessel Coronary Artery Disease

Study objectives: We reviewed our short- (30 days) and long-term (up to 17 years) experience with surgical revascularization for patients with angiographically documented isolated single-vessel coronary artery disease.

Design: Retrospective study of single-vessel coronary artery bypass procedures performed from January 1980 through June 1996. During this time, 100 consecutive patients underwent a single-vessel coronary artery bypass. All patients were men with a mean age of 59±9 years (range, 35 to 78 years) and a mean ejection fraction of 56±8% (range, 35 to 77%). The vessels bypassed included the left anterior descending in 66 (66%), right coronary artery in 31 (31%), and the obtuse marginal in 3 (3%).

Results: Short-term results reveal no deaths and six (6.0%) complications. Long-term follow-up by chart review and telephone survey was available in 87 (87%) patients at a mean of 46.9 months (range, 12 to 151 months). Cumulative freedom from angina and repeated revascularization was 93% and 98% at 1 year and 55% and 81% at 10 years, respectively (Kaplan-Meier).

Conclusion: Single-vessel coronary artery bypass for isolated single-vessel disease can be performed with minimal morbidity and no mortality and provides excellent long-term relief of angina.

Femoropopliteal bypass (fem-pop bypass) for peripheral arterial disease

Femoropopliteal (fem-pop) bypass surgery is used to bypass diseased blood vessels above or below the knee.

To bypass the blocked blood vessel, blood is redirected through either a healthy blood vessel that has been transplanted or a man-made graft material. This vessel or graft is sewn above and below the diseased artery so that blood flows through the new vessel or graft.

Before you have surgery, the doctor will determine what type of material is best suited to bypass the blood vessel. Whenever possible, the surgeon will choose to use an existing piece of vein taken from the same leg. Man-made graft materials (such as polytetrafluoroethyline [PTFE] or Dacron) are more likely to become narrowed again, but they are still effective.

The section of vein or man-made blood vessel graft is sewn onto both the femoral and popliteal arteries so that blood can travel through the new graft vessel and around the existing blockage

Biomechanics of Coronary Artery and Bypass Graft Disease

Department of Cardiothoracic Surgery, Kings College Hospital, London, United Kingdom

^_* Address correspondence to Dr John, Department of Cardiothoracic Surgery, Kings College Hospital, Denmark Hill, London, SE5 9RS, United Kingdom .

The contribution of biomechanical factors to the incidence and distribution of coronary artery and bypass graft disease is underrecognized. This review examined the literature to determine which factors were relevant and the evidence for their importance. It identified two primary biomechanical factors that predispose to disease: (1) low-wall shear stress and (2) high-wall mechanical stress or strain. A range of secondary biomechanical factors have also been identified and include: vessel geometry; vessel movement; vessel wall characteristics and the presence of reflection waves. Potential surgical approaches for minimizing these effects are discussed.

Molecular engineering of vein bypass grafts.

Department of Vascular and Endovascular Surgery, Brigham and Women's Hospital, Boston, MA 02115, USA. mconte@partners.org

Surgical bypass of arterial occlusions using autogenous vein provides an effective treatment for many patients with advanced coronary or peripheral atherosclerosis. However, the long-term benefit of bypass surgery is limited by the development of de novo occlusive lesions within the vein graft, which occurs in a significant percentage of patients over time. The pathophysiology of vein graft failure involves a complex interplay between an acute vascular injury response and the hemodynamic adaptation of the vein to arterial forces. Cell proliferation, inflammation, and matrix metabolism are critical components of postimplantation remodeling. Conventional pharmacotherapy has had limited impact on graft failure. Vein grafts present a unique and attractive opportunity for molecular engineering, which is defined for purposes of this review as the local application of genomic (eg, gene transfer or gene inhibition) or proteomic interventions designed to alter the healing response. The critical enabling technologies for these strategies are described, with a perspective on preclinical and clinical development for this indication. The recently completed clinical trials of edifoligide (E2F decoy oligodeoxynucleotide) provide important lessons for future studies. A better understanding of the remodeling response of vein grafts in humans is required to design effective molecular therapies and to define the appropriate target populations and surrogate markers for future clinical trials.

PMID: 17544027 [PubMed - indexed for MEDLINE]

Genetic interventions for vein bypass graft disease

Department of Surgery, Brigham and Women's Hospital, Boston, MA 02115, USA.

The failure of vein bypass grafting in the coronary or lower extremity circulation is a common clinical occurrence that incurs significant morbidity, mortality, and cost. Vein grafts are uniquely amenable to intraoperative genetic modification because of the ability to manipulate the tissue ex vivo with controlled conditions. Although the pathophysiology of vein graft failure is incompletely understood, numerous relevant molecular targets have been elucidated. Interventions designed to influence cell proliferation, thrombosis, inflammation, and matrix remodeling at the genetic level have been described, and many have been tested in animal models. Both gene delivery and gene blockade strategies have been investigated, with the latter now reaching the stage of advanced clinical trials. This review describes the basic and translational science of genetic interventions for vein graft disease and the current state of application in the clinic.