The Blaylock/Taussing Shunt (B/T Shunt)

Zachary's first open heart operation was the modified Blalock-Taussig (B/T) Shunt. This procedure was performed by Dr. Edward Bove at the University of Michigan Medical Center when Zachary was 6 days old. First I'll explain why this procedure was necessary and then I'll tell you what the procedure actually involves. In the fetal circulation there is an extra blood vessel called the ductus arteriosus. It is a very short blood vessel extending from the pulmonary artery to the aortic arch. Before the baby is born it functions to shunt blood away from the lungs and into the main arterial circulation. The ductus arteriosus closes within the first few days after the baby is born and then the right ventricle pumps blood only to the lungs. Zachary's problem was that his heart developed with only one functional ventricle and it was pumping blood into his aorta [he actually had a normal aorta and a stenotic(narrowed) pulmonary artery coming off of the one ventricle]. Consequently, the only way any blood could get to his lungs was from the aorta, through the ductus arteriosus, into the right and left pulmonary arteries and then into the lungs.

We knew about the condition of Zachary's heart before he was born and decided he should be born at the University of Michigan so that he could be close to his surgeon. Immediately after he was born he was taken to another room and an i.v. was started. He was given a special prostaglandin that told his body not to close the ductus arteriosus. Zachary was able to get blood to his lungs and he was able to maintain an oxygen saturation of ~75% (normal is >95%). This was enough to survive but he couldn't stay on prostaglandin forever.

The next step was to do the B/T shunt. The concept is really very simple whereas the procedure itself is not. Basically, a replacement for the ductus arteriosus had to be put in. The procedure involved making an incision between the ribs on the back right side of Zachary's chest to expose the right side of the heart and the right sided blood vessels. Dr. Bove then sewed a 3.5 millimeter goretex tube between the right subclavian artery (a branch off of the aorta) and the right pulmonary artery (the right and left pulmonary arteries are connected). This allowed direct blood flow to the lungs in virtually the same way as the ductus arteriosus had. Zachary was able to maintain an oxygen saturation of ~75% and could be taken off the prostaglandin. Luckily, this surgery did not require the use of the heart-lung machine or the stopping of the heart to be performed. The B/T shunt works to maintain the O2 sats for ~4-6 months at which time Zachary would be ready for his next procedure, the Hemi-Fontan.

Photos of Zachary in the Hospital