This year, according to the American Heart Association, 1.26 million people will have a heart attack. Heart attacks are caused by blockages in the coronary arteries. In order to get blood flow back to the arteries, heart bypass surgery is done. Heart bypass surgery is usually done when a patient has multiple areas of blockages in his arteries. Veins from the legs and an artery from the chest wall are used as conduit to create the new bypass for blood flow. Heart bypass can have complications.
Infection
A large incision in the chest wall is made in order to gain access to the heart, after which the sternum is opened with a saw. The surgeon then will free up the left internal mammary artery, which is used to bypass the left coronary artery. Sternal wound infections can occur when this blood flow is disrupted. Diabetic patients are at increased risk. Removal of the sternum is necessary if the infection is not responsive to long-term antibiotics. This is a rare but potentially life-threatening complication.
Cardiopulmonary Bypass Machine Complications
The use of the cardiopulmonary bypass machine enables the surgeon to drain the heart of blood in order to operate on it. The machine substitutes for the heart and maintains blood flow to the rest of the body during the operation. Blood is run through a series of tubes through the machine and then back to the patient. Extra fluid is added to the machine as blood travels through it, creating a dilution of the blood. Heparin is also introduced in order to prevent blood clots. This aberrant method of perfusing the body with blood causes an inflammatory response, which can cause kidney failure and other organ failure. Patients are at risk of stroke because of the cardiopulmonary bypass machine according to the Merck Manual Online. Stroke occurs in approximately 1.5 percent of patients. Diabetic patients, patients who smoke and elderly patients have a higher risk of stroke.
Arrythmias
The conduction system of the heart is extremely sensitive to handling. The sinus node, which lies within the left atrium and the AV node, is just above the ventricles and can be easily damaged with overly vigorous handling or retraction. Atrial fibrillation occurs in 15 to 40 percent of bypass patients and is usually controlled with medication. About 1 percent of patients will have a heart attack after the operation.
References
- American Heart Association.org: Cardiovascular Disease Statistics
- MayoClinic.com: Coronary Artery Disease: Angioplasty or Bypass Surgery?
- BiomedCentral.com: Superficial and Deep Sternal Wound Infection after more than 9000 coronary artery bypass grafts, incidence, risk factors and mortality. Abbas Salehi Omran, MD and et.al. BMC Infectious Disease. 2007
- MerckManualOnline.com: Coronary Artery Bypass Grafting (CABG)
