CORONARY ARTERY BYPASS GRAFT

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A coronary artery bypass graft or CABG is performed to improve circulation to heart muscle. In people who severe coronary artery decease. In this procedure a healthy artery or vein from another part of the body is connected or grafted to the blocked coronary artery. The grafted artery or vein bypass the blocked portion of coronary artery carrying oxygen riched blood to heart muscle. One or more coronary arteries maybe bypass during the single operation. Before the surgery, an intravenous line would be started and you maybe given a medication to help you relax. CABG procedure are under general anesthesia which would put you to sleep for the duration of the operation. A breathing tube would be inserted through your mouth and into your throat that help you breath.

A catheter will be placed to your bladder to drain your urine. CABG surgery generally take 3 to 6 hours, during your conventional bypass surgery, your surgeon begins by making a decision in a skin over your breastbone. He or she will begin cut your breastbone and move your rib cage in order to get your heart. The after procedure, your circulatory system would be connected to cardial pulmonary bypass pump or heart lung machine. This machine temporally perform the function of your function of your heart and lung during the surgery, allowing your heart to be stopped while the surgeon sew the grafts in the place. One or two blood vessel, is typically used for the graft.

With the grafts securely emplace, your surgeon will use electrical signal to restore the heart beat and attach a temporary pacemaker to heart. Once, your heart is again beating normally the heart lung machine would be disconnetted. Your surgeon would wire the breastbone back together and sew the skin. A temporary drainage tube would be placed through the skin. Two other types of CABG procedures have recently been developed, Off-pump and Minimally invasive bypass surgery. Off-pump CABG just also called beating heart bypass grafting because the heart isn't stopped and heart lung machine isn't used. Instead a mechanical device is used to steady the part of the heart when grafting is being done. Surgeon performs minimally invasive bypass procedure using specially design instrument. This procedure sometime require a heart lung machine.

After surgery, you'll be taken to Intensive Care Unit (ICU). The activity of your heart would be carefully monitored. If necessary, the pacing wire would be used to temporary control your heart rate. The chest tube would be remained in place to drain excess blood and air from the chest cavity. Once you can breath on your own, your breathing tube would be remove and replace the oxygen mask. The bladder catheter would remain in place. As you recover over the next 3 or 4 days, all of these devices would be gradually removed.

The Hemodynamics of Vein Grafts: Measurement and Meaning

Christopher L. Skelly, MD, Shari L. Meyerson, MD, Michael A. Curi, MD, Francis Loth, PhD, and Lewis B. Schwartz, MD, Chicago, Illinois
INTRODUCTION

The first successful experimental venous bypass grafts were created by Nobelist Alexis Carrel in 1906 in the Hull Physiologic Laboratory (now Culver Hall) at the University of Chicago.1 Over the ensuing century, infrainguinal autologous bypass has become increasingly applied, and approximately 100,000 grafts are now created annually in the United States. The safety and efficacy of the procedure have improved markedly in recent years. In large series, the mortality from infrainguinal by- pass approaches 2%, with major morbidity including myocardial infarction, cerebrovascular accident, and renal failure estimated at about 7%.2 The risk of immediate graft failure and limb loss also remains at about 7%. Thus, the vast majority of patients enjoy a favorable immediate operative result and revascularization. However, the lifespan of the graft is highly variable and, despite the initial technical success, grafts fail in subsequent years at an alarming rate. For all grafts in all patients, the reported 5 year primary patency, secondary patency, and limb salvage rates are about 60, 75, and 85%, respectively.2 These patency rates continue to slowly decline over the next 5 years to 40, 45, and 50%. This incessant attrition of functioning vein grafts remains the most important and frustrating limitation of the procedure.

Considerable attention has been devoted to improving the long-term results of peripheral vein grafting, with special emphasis on proper patient selection and refinement of surgical technique. Although certain clinical factors, such as renal fail- ure3,4 and diabetes,4-6 have implications for perioperative morbidity and long-term survival, none have predictive value for graft patency. The only remotely reliable predictors of graft patency are de- rived from the anatomic and hemodynamic aspects of the reconstruction itself, such as the quality and origin of the conduit and its outflow bed. The purpose of this review is to discuss the available techniques for the characterization of the hemodynamic environment of infrainguinal autologous bypass grafts, and the potential dependence of graft pa- tency on its hemodynamic environment.