Atrial septostomy
Encyclopedia
Atrial septostomy is a surgical procedure
in which a small hole is created between the upper two chambers of the heart
, the atria. This procedure is primarily used to treat dextro-Transposition of the great arteries
or d-TGA (often imprecisely called transposition of the great arteries), a life-threatening cyanotic
congenital heart defect
seen in infants. Atrial septostomy has also seen limited use as a surgical treatment for pulmonary hypertension
. This technique was developed in 1966 by American
surgeon
s William Rashkind and William Miller at the Children's Hospital of Philadelphia
.
There are two types of this procedure: balloon atrial septostomy (also called endovascular atrial septostomy, Rashkind atrial balloon septostomy, or simply Rashkind's procedure) and blade atrial septostomy (also called static balloon atrial septostomy).
, oxygen
-depleted blood ("blue") is pumped from the right side of the heart
, through the pulmonary artery
, to the lung
s where it is oxygenated. This is the pulmonary circulation
part of blood flow. The oxygen-rich ("red") blood then returns to the left heart
, via the pulmonary veins, and is pumped through the aorta
to the rest of the body, including the heart muscle
itself. This is the systemic circulation
part of blood flow, the other loop of an interconnected normal cardio-pulmonary system.
With d-TGA, certain major blood vessels are connected improperly, so oxygen-poor blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps oxygen-rich blood continuously back into the lungs through the pulmonary artery. This is a life-threatening situation due to the resultant low oxygen levels
throughout the body. Atrial septostomy allows more of the oxygen-rich blood to circulate throughout the body. The procedure is a temporary measure meant to help the patient survive until further corrective surgery can be done.
In the separate case of pulmonary hypertension, abnormally high blood pressure in the blood vessels within and connected to the lungs puts stress on the right side of the heart, potentially leading to right heart failure
. Atrial septostomy relieves some of this pressure, but at the cost of lower oxygen levels in the blood (hypoxia
). As with d-TGA, this surgery is not a definitive solution to the underlying medical problem.
s. In these cases, a balloon catheter
is guided through a large vein
into the right atrium
, during cardiac catheterization
. The catheter is threaded into the foramen ovale
, a naturally-existing hole between the atria that normally closes shortly after birth. The balloon at the end of the catheter is inflated so as to enlarge the foramen ovale enough that it will no longer become sealed. This allows more oxygenated blood to enter the right heart
(especially in the case of d-TGA) where it can be pumped to the rest of the body. The balloon is deflated and the catheter is removed.
Sometimes the initial surgery is not entirely successful, or there are other factors that make a simple balloon atrial septostomy impossible, such as an older patient whose foramen ovale has already closed. This is when a blade atrial septostomy is performed. The details of the procedure are largely the same, except that a small blade on the end of the catheter
is first used to create an opening between the right and left atria, before the insertion of the balloon.
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
in which a small hole is created between the upper two chambers of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, the atria. This procedure is primarily used to treat dextro-Transposition of the great arteries
Dextro-Transposition of the great arteries
dextro-Transposition of the great arteries , sometimes also referred to as complete transposition of the great arteries, is a birth defect in the large arteries of the heart...
or d-TGA (often imprecisely called transposition of the great arteries), a life-threatening cyanotic
Cyanotic heart defect
A cyanotic heart defect is a group-type of congenital heart defects . The patient appears blue , due to deoxygenated blood bypassing the lungs and entering the systemic circulation...
congenital heart defect
Congenital heart defect
A congenital heart defect is a defect in the structure of the heart and great vessels which is present at birth. Many types of heart defects exist, most of which either obstruct blood flow in the heart or vessels near it, or cause blood to flow through the heart in an abnormal pattern. Other...
seen in infants. Atrial septostomy has also seen limited use as a surgical treatment for pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
. This technique was developed in 1966 by American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
surgeon
Surgeon
In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...
s William Rashkind and William Miller at the Children's Hospital of Philadelphia
Children's Hospital of Philadelphia
The Children's Hospital of Philadelphia is one of the largest and oldest children's hospitals in the world. CHOP has been ranked as the best children's hospital in the United States by U.S. News & World Report and Parents Magazine in recent years. As of 2008, it was ranked #1 in the nation for...
.
There are two types of this procedure: balloon atrial septostomy (also called endovascular atrial septostomy, Rashkind atrial balloon septostomy, or simply Rashkind's procedure) and blade atrial septostomy (also called static balloon atrial septostomy).
Indications
In a normal heartHeart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
-depleted blood ("blue") is pumped from the right side of the heart
Right heart
Right heart is a term used to refer collectively to the right atrium and right ventricle of the heart; occasionally, this term is intended to reference the right atrium, right ventricle, and the pulmonary trunk collectively....
, through the pulmonary artery
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
, to the lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s where it is oxygenated. This is the pulmonary circulation
Pulmonary circulation
Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen-depleted Blood away from the heart, to the Lungs, and returns oxygenated blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn...
part of blood flow. The oxygen-rich ("red") blood then returns to the left heart
Left heart
Left heart is a term used to refer collectively to the left atrium and left ventricle of the heart; occasionally, this term is intended to reference the left atrium, left ventricle, and the aorta collectively....
, via the pulmonary veins, and is pumped through the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
to the rest of the body, including the heart muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
itself. This is the systemic circulation
Systemic circulation
Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. This physiologic theory of circulation was first described by William Harvey...
part of blood flow, the other loop of an interconnected normal cardio-pulmonary system.
With d-TGA, certain major blood vessels are connected improperly, so oxygen-poor blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps oxygen-rich blood continuously back into the lungs through the pulmonary artery. This is a life-threatening situation due to the resultant low oxygen levels
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
throughout the body. Atrial septostomy allows more of the oxygen-rich blood to circulate throughout the body. The procedure is a temporary measure meant to help the patient survive until further corrective surgery can be done.
In the separate case of pulmonary hypertension, abnormally high blood pressure in the blood vessels within and connected to the lungs puts stress on the right side of the heart, potentially leading to right heart failure
Cor pulmonale
Cor pulmonale or pulmonary heart disease is enlargement of the right ventricle of the heart as a response to increased resistance or high blood pressure in the lungs ....
. Atrial septostomy relieves some of this pressure, but at the cost of lower oxygen levels in the blood (hypoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
). As with d-TGA, this surgery is not a definitive solution to the underlying medical problem.
Procedure
The majority of atrial septostomies are performed on infants with d-TGA or other cyanotic heart defectCyanotic heart defect
A cyanotic heart defect is a group-type of congenital heart defects . The patient appears blue , due to deoxygenated blood bypassing the lungs and entering the systemic circulation...
s. In these cases, a balloon catheter
Balloon catheter
A balloon catheter is a type of "soft" catheter with an inflatable "balloon" at its tip which is used during a catheterization procedure to enlarge a narrow opening or passage within the body...
is guided through a large vein
Vein
In the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...
into the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
, during cardiac catheterization
Cardiac catheterization
Cardiac catheterization is the insertion of a catheter into a chamber or vessel of the heart. This is done for both investigational and interventional purposes...
. The catheter is threaded into the foramen ovale
Foramen ovale (heart)
In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...
, a naturally-existing hole between the atria that normally closes shortly after birth. The balloon at the end of the catheter is inflated so as to enlarge the foramen ovale enough that it will no longer become sealed. This allows more oxygenated blood to enter the right heart
Right heart
Right heart is a term used to refer collectively to the right atrium and right ventricle of the heart; occasionally, this term is intended to reference the right atrium, right ventricle, and the pulmonary trunk collectively....
(especially in the case of d-TGA) where it can be pumped to the rest of the body. The balloon is deflated and the catheter is removed.
Sometimes the initial surgery is not entirely successful, or there are other factors that make a simple balloon atrial septostomy impossible, such as an older patient whose foramen ovale has already closed. This is when a blade atrial septostomy is performed. The details of the procedure are largely the same, except that a small blade on the end of the catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
is first used to create an opening between the right and left atria, before the insertion of the balloon.
Risks
As with any surgery, there are certain risks to atrial septostomy, including tearing of the cardiac tissue, arrythmias, and rarely, death.External links
- Endovascular atrial septostomy information for the public from the National Institute for Health and Clinical ExcellenceNational Institute for Health and Clinical ExcellenceThe National Institute for Health and Clinical Excellence is a special health authority of the English National Health Service , serving both English NHS and the Welsh NHS...
- Interventional procedure overview of balloon or blade atrial septostomy from the National Institute for Health and Clinical ExcellenceNational Institute for Health and Clinical ExcellenceThe National Institute for Health and Clinical Excellence is a special health authority of the English National Health Service , serving both English NHS and the Welsh NHS...
- The Merck Manual of Diagnosis and Therapy, 18th edition, pp. 2416, 2417. Merck & Co., Inc., 2006. ISBN 978-0-911910-18-6