Cardiopulmonary bypass Health Dictionary

A technique by which narrowing or blockage of an artery (see ARTERIES), vein (see VEINS) or a section of the gastrointestinal tract is bypassed using surgery. Arterial blockages – usually caused by ATHEROSCLEROSIS – in the carotid, coronary or iliofemoral arteries are bypassed utilising sections of artery or vein taken from elsewhere in the patient. Tumour growths in the intestines are sometimes too large to remove and can be bypassed by linking up those parts of the intestines on each side of the growth.... bypass operation

The administration of life-saving measures to a person who has suffered a cardiac arrest. A person in cardiac arrest is not breathing and has no detectable pulse or heartbeat. First, mouth-to-mouth resuscitation (see artificial respiration) is given; if this fails to restart breathing, repeated chest compressions, using the heel of

the hand, are applied to the lower breastbone until trained help arrives.

Both these measures are used to restore blood circulation to the brain.

Brain damage is likely if the brain is starved of oxygen for more than 3–4 minutes.... cardiopulmonary resuscitation

The use of life-saving measures of mouth-tomouth resuscitation and external cardiac compression massage in a person who has collapsed with CARDIAC ARREST. Speedy restoration of the circulation of oxygenated blood to the brain is essential to prevent damage to brain tissues from oxygen starvation. The brain is irreversibly damaged if it is starved of oxygen for more than 4–5 minutes. Someone whose heart has stopped will be very pale or blue-grey (in particular, round the lips) and unresponsive; he or she will not be breathing and will have no pulse. It is important to determine that the collapsed person has not simply fainted before starting CPR. The procedure is described under car-diac/respiratory arrest in APPENDIX 1: BASIC FIRST AID. In hospital, or when paramedical sta? are attending an emergency, CPR may include the use of a DEFIBRILLATOR to apply a controlled electric shock to the heart via the chest wall.... cardiopulmonary resuscitation (cpr)

When coronary arteries, narrowed by disease, cannot supply the heart muscle with su?cient blood, the cardiac circulation may be improved by grafting a section of vein from the leg to bypass the obstruction. Around 10,000 people in the United Kingdom have this operation annually and the results are usually good. It is a major procedure that lasts several hours and requires the heart to be stopped temporarily, with blood circulation and oxygenation taken over by a HEART-LUNG MACHINE.... coronary artery vein bypass grafting (cavbg)

Procedures to bypass the blockage or narrowing of an artery or vein or any part of the digestive system. Arteries can become blocked or narrowed in atherosclerosis. Obstructions can be bypassed using sections of healthy artery or vein from elsewhere in the body or using synthetic tubing. Veins are bypassed most often in patients with diseases of the liver that cause portal hypertension and bleeding oesophageal varices. This kind of bypass is called a shunt. Intestinal bypasses are employed most commonly in patients with cancer in which tumour growth is too extensive to be removed. An obstructed bile duct can be bypassed by constructing a new opening into the digestive tract. (See also coronary artery bypass.)... bypass operations

A major heart operation to bypass narrowed or blocked coronary arteries using additional blood vessels (such as a mammary artery) to improve blood flow to the heart muscle. This operation is used when symptoms of coronary artery disease have not been relieved by drugs or balloon angioplasty.

Before surgery, sites of blockage in the arteries are identified using angiography. In some cases, minimally invasive surgery can be used, avoiding the need to stop the heart and use a heart–lung machine during the operation. The long term outlook after a bypass is good, but the grafted vessels may also eventually become blocked by atherosclerosis.... coronary artery bypass

n. a surgical procedure to divert the flow of blood or other fluid from one anatomical structure to another; a *shunt. A bypass can be temporary or permanent and is commonly performed in the treatment of cardiac and gastrointestinal disorders. See also cardiopulmonary bypass; coronary artery bypass graft.... bypass

(CABG) *coronary revascularization in which a segment of a coronary artery narrowed by atheroma is bypassed by an *autologous section of healthy saphenous vein or internal mammary artery at *thoracotomy. The improved blood flow resulting from one or more such grafts relieves *angina pectoris and reduces the risk of *myocardial infarction. Recently developed techniques of *minimally invasive surgery have enabled the operation to be performed without the need for thoracotomy.... coronary artery bypass graft

any of several procedures of *bariatric surgery that allow food to bypass parts of the gut in order to reduce absorption of nutrients and calories. Such operations often lead to greater weight loss than restrictive procedures, such as *gastric banding and *stomach stapling, but there are significant long-term complications relating to chronic malabsorption and patients must remain under long-term specialist follow-up.... gastric bypass surgery