Nikaidoh Procedure

(See Normal Heart Image for comparison)

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Nikaidoh Procedure:

1. They slice a section of the pulmonary artery and  of the aorta (including the valve AND with the coronary arteries* intact) to switch their positions
2. They remove the section of the wall (septum) that’s between the ventricles near the aorta and pulmonary artery
3. They remove part (or all) of the pulmonary valve
4. They place a patch (of pericardium from the sac around the heart) to both close the VSD and to widen the vessel that flows out of the left ventricle. [This widening is just like if you cut open a letter "o"--so it looks like a backwards "c"--and then sewed it onto a letter "l" to form a letter "D".]
5. They reattach the Aorta (including valve and coronary arteries*) so it comes out of the left ventricle as it does in a normal heart. If the coronary arteries are pulled too much or can’t reach the new position, they remove and reattach the coronary arteries so they’re not pulled too tight to work right.
6. They cut a slit in the narrowed part of the pulmonary artery and then use a patch (of pericardium) to make the vessel bigger on one end. (Imagine you have a skirt that fits perfectly at the waist but is too narrow at the bottom so your feet can barely fit through (like a cone-shape). So, you cut a slit from the bottom of the skirt up to the waistband. Next, you add a triangle-shaped patch of fabric so that the skirt is just as wide at the bottom as at the waist. Now you have a pencil skirt that you can actually use!  They fix the pulmonary artery like that so it’s not too narrow on one end anymore.]
7. They reattach the pulmonary artery so it comes out of the right ventricle as it does in a normal heart.

This procedure is used to surgically correct a heart with this combination of defects:

•  Pulmonary  Stenosis [pulmonary=having to do with the lungs, stenosis=narrowing of a passage, ] – a narrowing of the pulmonary artery (which carries blood from the heart to the lungs) at or near the pulmonary valve.
• Transposition of the Great Arteries (TGA) [transposition=switch the order, great arteries=the aorta & the pulmonary artery] – the positions of the great vessels are switched so that the aorta (which carries oxygen-rich blood to the body) is closer to the oxygen-poor blood AND the pulmonary artery (which carries oxygen-poor blood to the lungs) is closer to the oxygen-rich blood.  It is usually accompanied by a hole in the wall between the ventricles (ventricular septal defect or VSD).
• Ventricular Septal Defect (VSD) [septum=wall between the chambers of the heart, ventricles=lower chambers of the heart] – holes in the inner walls of the heart allowing extra blood flow between the two lower chambers of the heart (ventricles). This causes the oxygen-rich and oxygen-poor blood to mix before leaving the heart.

*coronary arteries are the small blood vessels that branch off the aorta just as it leaves the heart to “feed” oxygenated blood to the heart muscle.