What is a device closure?
Device closure is a surgical procedure to close a defect in the walls separating the chambers of the heart. In this procedure a specialised cardiac device is placed in the defect to close it. This is a minimally invasive surgical procedure. The mode of surgery is similar to an angioplasty. Device closure surgery is a viable alternative to conventional open heart surgery. The risk associated with an open heart surgery is more as compared to device closure. Similarly the complications are also less leading to a faster recovery.
Why is a device closure surgery performed?
The heart is composed of two upper chambers called the atria and the two lower chambers called the ventricles. They relax and contract alternatively to receive and pump blood. The deoxygenated blood from all over the body is brought into the right atrium. The right atrium then contracts and pushes the blood into the right ventricle through the mitral valve. From the right ventricle the pulmonary arteries take the blood to the lungs for oxygenation. The pulmonary veins then take the oxygenated blood from the lungs to the left atrium. The blood then passes on to the left ventricle. As the left ventricle contracts, the blood gets pumped into the aorta. The aorta then branches out into smaller blood vessels that supply various parts of the body.
The two atria and the two ventricles are separated by muscular walls called septa. These septa prevent the mixing up of deoxygenated and oxygenated blood. In certain individuals defects in the septal walls occur. Most of these defects are congenital or present at birth. These defects allow the leakage of blood to the neighbouring chamber. This mixing up of the blood can cause problems with the normal circulatory mechanism of the heart.
A device closure surgery is performed to fix the defect and help restore the normal circulatory mechanism of the heart. If the defect is small the associated problems will be minimal in nature. They may not require any treatment at all. The most disturbing sign of these defects will be a murmur picked up by a stethoscope.
If the defects are large they may create complications and disturbing symptoms. The complications of septal defects are due to the congestion of the lungs and increased work load of the heart.
Types of septal defects-
There are various types of septal defects. The defects occurring in the atrial walls are called as atrial septal defects. The defects in the ventricular septum are called as ventricular septal defects.
The most common atrial septal defects are-
• Ostium secundum atrial septal defect- The commonest of atrial septal defect occurring due to a defect in the septal wall formation
• Patent foramen ovale- Foramen ovale is an opening present in the atrial septum in foetuses which usually closes soon after birth. A Patent Foramen Ovale (PFO) is a condition where the foramen ovale has failed to close. The patency of the opening means a chance for the oxygen rich and poor blood to mix together.
• Sinus venosus atrial septal defect- This defect occurs near the junction of the superior or inferior venacava and the right atrium
• Common or single atrium - there is absolutely no separation between the two atria
The ventricular septal defects are classified according to their position.
Symptoms indicating device closure:
An ASD device closure procedure is indicated if the symptoms are prominent. Some of the common symptoms of septal defects that require a device closure are:
• Shortness of breath or gasping
• Fatigue without any effort
• Swollen legs or feet
• Skipped heart beats
• Presence of heart murmurs
Device closure in India:
Device closure procedure is done in all major hospitals in India. The approximate cost of device closure in India is approximately 7300 USD
Types of ASD closure devices and PFO closure device:
The Amplatzer® Septal Occluder System and the Gore Helex® Septal Occluder system are the most commonly used closure devices. Though dissimilar in design, positioning and functioning are similar in nature.
The Amplatzer® Septal Occluder consists of two attached circular discs made of polyester encased in a wire mesh made of a nickel-titanium metal alloy. The discs are positioned on either side of the defect. The larger disc is in the left atrium and the smaller disc is in the right atrium.
The Gore Helex® Septal Occluder system device is composed of a single piece of nickel titanium circular wire covered with a thin membrane made of Gore-Tex.
Device closure procedure:
The procedure is similar to an angiogram or angioplasty. The procedure is done under sedation. A catheter is inserted into the femoral vein through a small incision in the groin. Then it is slowly guided and advanced through the vein and into the heart. Once it reaches the heart chamber having the defect, the closure device is moved up through the catheter. Once the desired position is reached the device is pushed out of the catheter. The device will start expanding within the defect to close it completely. The catheter is then slowly withdrawn and the groin incision is covered by a dressing.
Device closure risks and complications:
Though a comparatively safe procedure, ASD and PDA device closure also has its share of risks and complications.
Device closure risks:
• Allergic reaction to the anaesthetic
• Allergic reaction to the dye
• Bleeding and bruising during catheterisation in the groin
• Injury to the blood vessels and nerves in the groin
Device Closure Complications:
• Allergic reaction to the metallic component of the device
• Dislodgement of the device
• Pulmonary embolism due to a dislodged device.
• Dislodgement of the clot surrounding the device
• Occurrence of stroke due to a dislodged clot.
• Onset of cardiac arrhythmias
• Perforations in the heart during catheterisation
Do's and don’ts after the treatment
Being a minimally invasive surgery recovery is fast. The precautions as suggested by the doctor should be strictly followed. They may include avoiding strenuous exercises, lifting of weights, climbing stairs etc. The wound in the groin should be properly taken care of.