Studies examine issues in pediatric cardiology

"More than ten years ago, Miami Children’s Hospital demonstrated that balloon expandable stent implantation in infants was safe and effective, and we now provide evidence that there is a sustained long-term benefit to these children,” said Evan M. Zahn, M.D., of Miami Children’s Hospital, and lead investigator of the study. “As a young child grows over time, these stents can be safely and effectively enlarged in the catheterization laboratory or removed in the operating room during another scheduled procedure. The next step will be to assess whether a stent implanted during infancy can ultimately be enlarged to a normal adult size, essentially providing a lifetime of effective treatment from a catheter procedure performed in infancy.”

Dr. Zahn will present this study on Monday, March 26, at 10 a.m. in Hall H.

Six Years’ Experience of Outcome After Percutaneous Pulmonary Valve Implantation (Presentation Number 823-4)

In 2000, percutaneous pulmonary valve implantation (PPVI) and repair has emerged as an additional therapy to avoid re-operation in young patients with congenital heart disease. Although long-term outcomes are not yet available, researchers from the Great Ormond Street Hospital for Children and UCL Institute of Child Health in London have collected sufficient information to offer the first mid-term evaluation of this technique.

Over the past six years, peri- and post-procedural complications in children with congenital heart disease have led to the removal of percutaneous pulmonary valves. In this study, researchers sought to analyze the influence of learning curve and technique modification on the need for device removal. To do this, patients were divided into two study groups: one which included the first 50 patients, and a second group of patients (n=87) who underwent PPVI after improvement of the engineering of the device, better patient selection and improvement in procedural technique, such as introducing post dilatation. Survival curves for freedom of device removal were calculated for both cohorts.

During follow-up, 19 out of the total 137 patients underwent device removal. In the first group, reasons included the following: “hammock effect” (vein wall hanging into stent, narrowing of a passageway, n=4), stent fractures (n=1), valve dislodgement (n=2), coronary compression (n=1), right pulmonary artery obstruction (n=1) and residual stenosis (n=6). These complications led to modification of the technique, including device alterations, second PPVI, enhanced imaging and improved patient selection. In group two, device removal was necessitated by complications including endocarditis (infection of the heart lining, n=2), outgrown conduit or stent (n=1) or thomograft rupture (n=1), for which no technique modification could be considered.

"Recently introduced as an alternative to surgery, percutaneous pulmonary valve implantation is one of the most exciting developments in the field of interventional cardiology,” said Sachin Khambadkone, M.D., of Great Ormond Street Hospital and an investigator on this trial.