Columbus, OH - October 2016
Pediatric interventional cardiologists have been increasingly utilizing premounted stents to treat vascular stenosis in infants and children with congenital heart disease. Designed and tested for use in adult biliary tracts, renal arteries or other adult systemic vasculature, these premounted stents have a lower profile and can be more stable on the delivery balloon than hand-crimped stents.
Premounted stents may offer a therapeutic option beyond surgery, says Brian A. Boe, MD, an Interventional Cardiology fellow in The Heart Center at Nationwide Children’s Hospital who will join the hospital’s faculty in January 2017. The relatively recent adoption of these stents for the pediatric population, though, has meant that not much data exists outside of a few acute outcome publications.
”We are constantly evaluating the procedures performed in the catheterization laboratory to ensure we are achieving the anticipated outcomes and providing the best care for our patients,” Dr. Boe says.
A recent study led by Dr. Boe and Aimee K. Armstrong, MD, director of Cardiac Catheterization and Interventional Therapies at Nationwide Children’s, reports good medium-term outcomes for the stents – while also noting a higher rate of in-stent stenosis for premounted stents versus manually-crimped ones.
Published in Pediatric Cardiology, the study reviewed 58 premounted stent cases at a single pediatric institution over an 8-year period. The median age at implantation was 1.9 years, and the location of implantation was most often the pulmonary artery (75.4 percent). The most frequently used stents were the Atrium iCAST, FDA-approved for tracheobronchial strictures (34.8 percent); the Cordis PALMAZ Blue, approved as a biliary stent (21.7 percent); and the Cordis PALMAZ Genesis, also a biliary stent (17.4 percent).
The study found a 97 percent procedural success rate with immediate improvement in vessel size and hemodynamics. Complications occurred in 17 percent of cases, including two cases requiring surgical removal. Only one stent fracture occurred, and that was five months after implantation. Overall, only 10 percent of premounted stents required surgical reintervention over a median follow-up time of 3.1 years.
As expected, the authors found that younger and smaller patients typically require reintervention (usually catheter-based) by three years after implantation, most often because these stents need to be dilated as the child grows.
“It’s important to have a strong team in place,” says Dr. Boe. “Initial discussion among the primary cardiologist, interventionalist and surgeon allows you to anticipate interventions, which may include the use of premounted stents.”
The study is the first to evaluate in-stent stenosis for premounted stents in congenital heart disease patients. Researchers discovered that 42 percent of these patients were diagnosed with in-stent stenosis, a higher rate than previously seen for hand-crimped stents. There were no factors associated with the development of stenosis, however.
“These stents are effective, but we recommend follow-up catheterization for all premounted stents in this population because of the issues surrounding patient growth and in-stent stenosis,” says Dr. Boe.
Boe BA, Zampi JD, Schumacher KR, Yu S, Armstrong AK. The use and outcomes of small, medium and large premounted stents in pediatric and congenital heart disease. Pediatric Cardiology. 2016 Aug 27. [Epub ahead of print]