In-stent Stenosis Clinical Trial
Official title:
Systemic Rapamycin (Sirolimus) to Prevent In-Stent Restenosis Following Pulmonary Artery Stent Placement
This is a research study to assess whether an oral medication can benefit some patients being
treated for peripheral pulmonary stenosis (PPS), which is narrowing of the blood vessels that
send blood to the lungs (pulmonary arteries).
In the cardiac catheterization laboratory, the investigators treat PPS by dilating the
narrowed segments of pulmonary arteries using balloon catheters. Sometimes the investigators
also place stents which are mesh tubes that help keep the narrowed vessel open. Some stents
suffer from in-growth of tissue into the stents which causes recurrent obstructions inside
the stent (i.e. making the opening inside the mesh tube narrow again), so called in-stent
stenosis (ISS).
The purpose of this study is to use a medication that is approved for use in children (for a
different purpose) to decrease the amount of cell ingrowth inside the stents (i.e. decrease
the problematic in-stent stenosis). The medication is called rapamycin, also known as
sirolimus (trade name Rapamune). It has antiproliferative properties which means that it
slows down cell division which the investigators believe cause the recurrent narrowing inside
stents.
Rapamycin is a medicine that can be taken by mouth as a liquid or pill or via a feeding tube.
There will still be a need for interventions in the catheterization laboratory but the
investigators hope that by taking this medicine some children would need fewer
catheterizations in the future. Our early experiences with a few patients who have been
treated with rapamycin due to in-stent stenosis in the pulmonary arteries suggest that it may
be helpful.
In this study, patients and families who are interested in possibly trying this new approach
will be randomized to sirolimus or no sirolimus. The investigators will compare the
developement of ISS over time between these groups, in a hope to learn whether oral sirolimus
reduces ISS development.
This is a research study to assess whether an oral medication can benefit some patients being
treated for peripheral pulmonary stenosis (PPS). PPS, which can be associated with several
different congenital heart diseases, is narrowing of the blood vessels that send blood to the
lungs (pulmonary arteries) to pick up oxygen before returning the blood to the heart and the
rest of the body. The right ventricle (RV) is the pumping chamber that pumps blood into the
pulmonary arteries and the lungs.
PPS can result in high RV pressure, reduced blood flow to one lung, or uneven blood flow
within either lung. If left untreated these abnormalities place affected children at risk for
abnormal RV function and failure of this pumping chamber which may be seen as decreased
ability to do exercise, heart rhythm problems, fainting, or even death.
In the cardiac catheterization laboratory, the investigators treat PPS by dilating the
narrowed segments of pulmonary arteries using balloon catheters. Sometimes the investigators
also place stents which are mesh tubes that help keep the narrowed vessel open. Some stents
suffer from in-growth of tissue into the stents which causes recurrent obstructions inside
the stent (i.e. making the opening inside the mesh tube narrow again), so called in-stent
stenosis (ISS). This effectively causes recurrent PPS and recurrence of the associated risks
listed above.
The purpose of this study is to use a medication that is approved for use in children (for a
different purpose) to decrease the amount of cell ingrowth inside the stents (i.e. decrease
the problematic in-stent stenosis). The medication is called rapamycin, also known as
sirolimus (trade name Rapamune), and has been used safely for many years in children and
adults after organ transplantation to prevent rejection of the new organ. It has
antiproliferative properties which means that it slows down cell division which the
investigators believe cause the recurrent narrowing inside stents. By slowing down the cell
division the investigators believe that the stents will stay open instead of becoming
narrowed inside again. This medicine is found in many types of stents placed in adults with
narrowed arteries around the heart (so called drug-eluding stents) and appear to help keep
these blood vessels open after heart attacks (or to prevent heart attacks). Such stents are
currently not available for pulmonary arteries; therefore the investigators give the medicine
by mouth instead (which has also been used in adults with stents in narrowed arteries around
the heart).
Rapamycin is a medicine that can be taken by mouth as a liquid or pill or via a feeding tube.
There will still be a need for interventions in the catheterization laboratory but the
investigators hope that by taking this medicine some children would need fewer
catheterizations in the future. The investigators believe it may help lessen the risk of
recurrent in-stent stenosis and the associated problems listed above. Our early experiences
with a few patients at BCH who have been treated with rapamycin due to in-stent stenosis in
the pulmonary arteries suggest that it may be helpful.
In this study, patients and families who are interested in possibly trying this new approach
will be randomized to sirolimus or no sirolimus. The investigators will compare the
developement of ISS over time between these groups, in a hope to learn whether oral sirolimus
reduces ISS development.
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