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Congenital heart defects can be classified into several categories according to the problems your child may experience. They include the following:
Problems that cause too much blood to pass through the lungs — These defects allow oxygen-rich (red) blood that should be traveling to the body to re-circulate through the lungs, causing increased pressure and stress in the lungs. Examples include the following:
- patent ductus arteriosus (PDA)
- atrial septal defect (ASD)
- ventricular septal defect (VSD)
- atrioventricular canal (AV canal or AVC)
Problems that cause too little blood to pass through the lungs — These defects allow blood that has not been to the lungs to pick up oxygen (and, therefore, is oxygen-poor) to travel to the body. The body does not receive enough oxygen with these heart problems, and the baby will be cyanotic, or “blue.” Examples include the following:
- tricuspid atresia (TA)
- pulmonary atresia (PA)
- transposition of the great arteries (TGA)
- tetralogy of Fallot (TOF)
Problems that cause too little blood to travel to the body — These defects are a result of underdeveloped chambers of the heart or blockages in blood vessels that prevent the proper amount of blood from traveling to the body to meet its needs. Examples include:
- coarctation of the aorta
- aortic stenosis
- pulmonary stenosis
A combination of several heart defects — These combinations create a more complex problem that can fall into several of these categories. Complex combination of heart defects include:
- hypoplastic left heart syndrome (HLHS)
- truncus arteriosis
- total anomalous pulmonary venous return (TAPVR)
Anatomically corrective procedures are required to make heart structures normal. Physiologically corrective procedures are required to separate and/or redirect the blue and pink blood circulations. These corrective procedures range from relatively simple (like closing a patch or tying off a vessel) to complex (switching vessels or re-routing blood strams). Most corrective operations require the use of a heart-lung machine. Some corrective surgical procedures provide complete correction of the normal physiology of the heart. Other corrective procedures provide an altered type of physiology of the heart but provide a permanent solution.
Pallative procedures are required to improve, but not correct, an abnormal heart function. Pallative operations are performed to improve the heart function, usually in children too young for corrective surgery. The aim is to lessen cyanosis, to control heart failure or to prepare the circulation for later repair.
Closure of ASD and VSD – smaller ASD and VSD can be closed with sutures or stitches. Larger defects require the use of a plastic patch. Occasionally, in complex defects, the patch is used not only to close the hole between the two ventricles but also to channel left ventricular blood flow through the right ventricle into the aorta through an intracardiac tunnel.
Correction of Narrow Valves – aortic, mitral, tricuspid and pulmonic are the four valves in the heart. They can narrow (stenosis) or regurgitant (leaky) or both. They can either be repaired or replaced, depending on the nature of the problem. The most common aortic and pulmonic stenosis is caused by congenital fusion of one or more valve leaflets. Repair is done using a heart-lung bypass machine and cutting the fused leaflets apart. Occasionally, the seat of the valve (annulus) is small, a condition called Hypoplastic. Enlargement of the pulmonic annulus is accomplished by cutting it and placing a trans-annular patch across it. The resulting valve leak is usually well tolerated for a decade or more. A small aortic annulus cannot be enlarged without valve replacement because it would cause excessive regurgitation (leaking). A regurgitant aortic valve can sometimes be repaired by tightening the loose leaflets in a procedure called a valvuloplasty. Narrow mitral or tricuspid valves can rarely be enlarged and usually need to be replaced. Regurgitant mitral or tricuspid valves can frequently be repaired by valvuloplasty.
Repair of Anomalous Pulmonary Venous Return – whether some or all four pulmonary veins are draining anomalously into a wrong cardia structure, the aim for surgery is to re-connect them to the left atrium. If the veins are neither obstructed nor narrow before surgery, the result can be excellent. Obstructed or narrow veins, however, tend to re-narrow after surgery and may require additional operations.
Arterial Switch Operation (ASO) – is the preferred anatomically corrective operation for both simple and complex forms of d-Transposition of the Great Arteries because it restores the structure and function of the heart to normal. The aorta and pulmonary arteries are severed from their transposed origins and reconnected in such a way that they receive the correct blood from the correct ventricle. After repair, the left ventricle should direct blood to the aorta and the right ventricle should send blood to the left ventricle. The arterial switch requires a separate transfer of the coronary arteries from the originally right-sided aortic stump to the new left-sided aortic root, the former pulmonary trunk.
Atrial Septostomy (Balloon or Blade) – the majority of atrial septostomies are performed on infants with d-TGA or other cyanotic heart defects. 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 left heart 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. This is when a Blade Atrial Septostomy is performed. The details of the procedure are largely the same as described above, 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.
Atrio-Ventricular (Common AV Canal) Repair – is an anomaly that consists of a large confluent ASD and VSD and an undivided, or common, inlet valve. Although surgical techiniques vary, repair requires a patch closure of the two defects and the separation of the common valve into a tricuspid and mitral valve, called a two-ventricle repair. It is rare when one of the ventricles is too small (condition called Unbalanced AV Canal) and a one-ventricle or Fontan Procedure is preferable. A Partial AV Canal (Ostium Primum) consists of a large ASD and a cleft (regurgitant) mitral valve. Repair for this is accomplished by patch closure of the defect and suturing the cleft.
Balloon Angioplasty – is a cardiac catheterization procedure used to correct a narrow blood vessel by inserting a balloon- tipped catheter and inflating the balloon at the point of narrowing to stretch the blood vessel.
Balloon Valvuloplasty – is a cardiac catheterization procedure used to correct a narrow valve by inserting a balloon-tipped catheter and inflating the balloon at the point of the narrowing to stretch the valve.
Blalock-Hanlon Procedure (creation of an ASD) – is a closed-heart operation aimed at improving the bluish cyanosis color in certain conditions such as Transposition of the Great Arteries or Tricuspid Atresia. While complete separation of blue and pink circulations is normally desirable in Transposition and several other CHD’s, the two circulations must mix within the heart for the child to do well. A hole in the atrium septum is an efficient way to accomplish such mixing. Eventually, anatomic or physiologic repair will follow.
Blalock-Taussig Shunt (BT Shunt) – shunts are surgical connections between two arteries or between a vein and an artery. The BT Shunt connects a branch of the aorta (usually the subclavian artery) to the pulmonary artery directly or by using a plastic tube to increase pulmonary blood flow.
Coarctation of the Aorta Repair – is a procedure that usually does not require a heart-lung machine. A variety of surgical methods are currently in use. Resection, or removal, of the narrowing and an end-to-end anastomosis (a surgical connection of arteries to form a passage), is rarely used due to high recurrence rate. Instead, an extended end-to-end anastomosis offers good long term repair by removing all of the abnormal wall. The subclavian patch repair uses part of the left subclavian artery to enlarge the aortic narrowing, but a plastic patch can also be used. Rarely is the narrow segment bypassed by a conduit or a graft.
Damus-Kaye-Stansel Operation – usually complements other corrective procedures. It was originally developed with the Rastelli Procedure for correcting TGA with a VSD without switching the transposed arteries. It is now frequently used as part of the Fontan Procedure in one-ventricle repairs to overcome any obstruction to the aortic blood flow. It consists of connecting the pulomonary trunk and the ascending aorta, and detaching the pulmonary artery branches. The pulmonary artery branches are supplied temporarily by an artificial shunt from the aortic branches. The aorta thus receives flow through both pulmonic and aortic valves.
Fontan Operations – Many versions of the physiologically corrective procedure exist and they continue being updated. The Fontan is reserved for complex heart abnormalities that cannot undergo a two-ventricle repair. Such hearts are grouped together as uni-ventrical, meaning that there is only one functioning ventricle, which must be left to propel the pink blood to the body. The blue and pink circulations are surgically separated by atrial partition and the blue side (IVC inferior vena cava and SVC superior vena cava) is connected directly to the pulmonary artery without any valves. There is no pump for the blue blood, but the circulation is still effective as long as the pressure in the lungs is low. The operation eliminated both the bluish cyanosis and allows for reasonable physical activities.
Kawashima Operation – is an intraventricular tunnel repair used for anatomic correction of Double Outlet Right Ventricle (DORV) where both the aorta and pulmonary artery originate from the right ventricle and the only exit from the left ventricle is a VSD. The VSD is left open and sometimes even enlarged to serve as the mouth into a tunnel leading from the left ventricle through to the right ventricle to the aorta. This tunnel is called an intracardiac conduit because it occurs completely within the heart. The tunnel is created in such a way as to separate the left ventricle to the aorta and the right ventricle flow to the pulmonary artery. This operation avoids the use of an extracardiac pulmonary conduit.
Konno Procedure – a procedure performed when there is narrowing below the aortic valve. this procedure cuts open the septum between the right and left ventricle and places a large patch so that the left ventricle outflow tract is enlarged. This surgical procedure often is done in combination with the Ross Procedure.
Maze Procedure – incisions which are made in the atria to block the path of an arrhythmia or atrial fibrillation.
Mustard Procedure – is also known as a Venous Switch and used for physiologically correction of d-Transposition of the Great Arteries. As with a similar procedure called the Senning Operation, the Mustard Procedure leaves the transposed origin of the aorta and pulomary artery unchanged. The Mustard instead switches the blood streams entering into the atria. Ultimately, the aorta receives the pink, oxygen-rich blood and the pulmonary artery carries the blue, oxygen-poor blood. This is accomplished by rerouting the blue veins from the right to the left atrium and the pink veins from the left to the right atrium using a partition or “baffle” harvested from the patient’s own pericardium (membranous sac that encloses the heart). The superior vena cava (SVC) and the inferior vena cava (IVC) are directed under the “baffle” into the left atrium (now carrying blue blood), left ventricle and pulmonary artery. The four pulmonary veins flow over the “baffle” into the right atrium (now carrying pink blood), then into the right ventricle and aorta. This operation has been, to a large extent, replaced by the Arterial Switch Operaton.
Norwood Procedures – are used to treat HLHS, a group of defects in which the left ventricle is very small or absent. There are 3 stages:
- Norwood I (sometimes called the BT Shunt) is a palliative operation – a fix, not a cure – performed in newborns as an emergency procedure using heart-lung machine. It converts the functionally single right ventricle to act as the left ventricle while the pulmonary trunk is surgically joined with the tiny aorta to form a large new aorta, using a modified Damus-Kaye-Stansel Procedure. The aortic arch is reconstructed as well, if necessary. The pulmonary artery branches are detached and connected to the new aorta by a small plastic tube, a procedure known as a modified Blalock-Taussig anastomosis. Norwood I enables an infant to grow up to 4-10 months of age when the second stage palliative operation can be undertaken.
- Norwood II (sometimes called the Glenn) is usually performed around 4-6 months of age. It converts the Blalock-Taussig anastomosis to a bi-directional Glenn or a Hemi-Fontan anastomosis in preparation for the eventual Fontan Procedure, which is the corrective repair. The Glenn and Hemi-Fontan consist of connecting both pulmonary artery branches to the superior vena cava, enabling blue blood to reach the pulmonary circulation directly without having to pass through the heart chambers.
- The Fontan Procedure is the third stage which occurs before the child enters kindergarden. This procedure eliminates cyanosis by directing the inferior vena cava to the pulmonary artery and partitioning the two atria.
One-and-One-Half Ventricle Repair – is a procedure used when the right ventricle is too small to handle the entire blue circulation, which ordinarily goes to the lungs for oxygenation. In this operation, the right ventricle is left to pump only the IVC (inferior vena cava) blood to the pulmonary artery, while the SVC (superior vena cava) blood reaches the pulmonary artery through the Glenn anastomosis.
Patent Ductus Arteriosus (PDA) Ligation – is a one of the truly corrective operations. Once the ductus is successfully closed, no further surgery is required. Ductal closure is a closed-heart operation consisting of cutting the ductus and sewing up the two stumps. In tiny, premature babies, ligation (tying off) of the ductus is preferred.
Pulmonary Artery (PA) Banding – is a temporary, palliative procedure that reduces excessive flow and pressure in the pulmonary artery. The pulmonary artery is surgically constricted (using a wide tape) to the point where heart failure due to excessive pulmonary blood flow is controlled. As the child grows, the banded artery remains the same size, causing the child’s color to become bluer. At this point, a corrective surgery may be carried out, or occasionally a shunt will be placed to restore the pink color.
Rastelli Procedure – is an anatomically corrective repair for heart defects that have in common a missing, defective, or obstructed pulmonary artery and a large ventricular septal defect. Truncus Arteriosus and Transposition of the Great Arteries, as well as other similar conditions, can benefit from this procedure.
The flow of blue blood to the lung circulation is established through a tube placed outside the heart, usually containing a valve. The large VSD is either closed with a patch or used to construct a new aortic outlet. The valve is placed from the right ventricle to the pulmonary artery. The VSD is closed in such a way as to separate the flow between the ventricles so that the right ventricle flow goes to the pulmonary artery and the left ventricle flow goes solely to the aorta. Such reconstructed hearts have all he components and function of a normal heart. However, the pulmonary conduit (tube w/valve) cannot grow with the child and will eventually require another surgery to replace it.
Ross Procedure – consists of replacing a faulty aortic valve with the patient’s own healthy pulmonic valve. It requires re-implantation of the coronary arteries into the reconstructed aortic root. The pulmonic valve is replaced with a biologic valve, either a homograft taken from a human cadaver donor or porcine, taken from a pig. This operation can be part of the Ross-Konno Procedure employed where there is an additional narrowing below the aortic valve. In the Konna Procedure, the narrow left ventricular outlet is approached through the right ventricle, the septum is cut open and filled with a large patch in such a way as to enlarge the left ventricular outflow tract.
Senning Procedure – a surgical technique where a tunnel or baffle is created inside the left and right atria in order to redirect blood. This “intra-atrial baffle” is created from tissue taken from the patient’s atrial wall. This procedure is similar to the Mustard Procedure.
Tetralogy of Fallot Repair – is repaired using a combination of a VSD closure and repair of the narrowings along the pulmonary artery path. An angled patch placed over the large VSD serves to channel left ventricular blood into the overriding, or straddling, aorta. Repair of pulmonary stenosis can involve sewing a patch in the right ventricular outflow tract, across the seat of the valve, pulmonary truck and pulmonary artery branches. When either the pulmonary valve or trunk is completely blocked (atretic), the conduit used in the Rastelli Procedure is required to complete the correction.
When the pulmonary artery is absent, small arteries originating from the aorta called Multiple Aorta Pulmonary Collateral Ateries (MAPCAs) supply the lung circulation. This type of Tetralogy requires multiple steps to correct. First, MAPCAs on the two sides need to be joined into a single vessel in two separate procedures, called Unifocalization. Correction is eventually accomplished using the Rastelli repair.
Waterson – a central shunt where the ascending aorta is connected to the right pulmonary artery.
Source: It’s My Heart and Wikipedia