Branch Pulmonary Artery Stenting

When is Branch pulmonary artery stenting done?

The pulmonary arteries are the vessels that supply the lungs.  There is one pulmonary artery for each lung.  These arteries may become narrow in specific circumstances.  Most commonly, the narrowing is seen in association with congenital heart defects such as Tetralogy of Fallot.  Occasionally, they become narrow in association with selected genetic conditions such as William's Syndrome. It is not uncommon to encounter persistent narrowing of  the pulmonary after previous surgery.  

 

When the branch pulmonary artery is narrow there is a need to relieve it. The specific reasons include:

  1. Unequal blood flow to the lungs can impact exercise tolerance and long term growth of the lungs

  2. There is potential danger for the narrowing to progress and the affected side may be completely cut off from circulation

  3. Following surgery for tetralogy of Fallot persistent narrowing of one of the pulmonary arteries can increase the leakage of blood in the pulmonary valve with a number of long term problems

  4. In selected patients, especially when narrowing of pulmonary arteries affects both sides, the pressure in the right side may increase unacceptably.  

 

 In addition to echocardiogram, it may be necessary to do a CT scan to define the narrowing.  Additionally, a nuclear scan can precisely tell us the exact percentage of blood reaching each of the lungs.

 

What is done during branch pulmonary artery stenting?

The affected vessel is crossed by a wire.  The stent is mounted on a balloon and expanded at the affected narrow part  of the vessel.  In order to ensure precision there is a need to place long tube (sheath) across the narrowing prior to the stent placement.

 

What complications can be expected?

  1. The stent may get displaced.  This is rare if adequate precautions are taken.

  2. Following expansion the part of the lung supplied by the previously narrow vessel may suddenly get flooded and this may necessitate intensive care and ventilation support.

 

What are the long term results?

 While stents provide lasting relief in the majority of the circumstances, they may need repeat dilations as the child grows.  Occasionally, there is ingrowth of tissue into the stent and this may necessitate repeat dilation or repeat stenting.