Study Demonstrates Risk Reduction in Pediatric Catheterizations

May 29, 2014—The Society for Cardiovascular Angiography and Interventions (SCAI) announced the presentation of a study, “Femoral Artery Compromise From Cardiac Catheterization in Children—a Multicenter Study by the CCISC (Congenital Cardiovascular Interventional Study Consortium)” by Thomas J. Forbes, MD, at the SCAI 2014 scientific sessions in Las Vegas, Nevada.

According to SCAI, the presentation demonstrated that two key steps can provide a two-thirds risk reduction of clotting that obstructs blood flow in femoral access cardiac catheterization procedures for infants with congenital heart disease.

The study drew data from the CCISC registry and involved children under the age of 18 who were treated at 21 pediatric cardiac catheterization laboratories. Investigators focused on factors that influence the risk that a blood clot will form in the femoral artery and obstruct blood flow in the leg during cardiac catheterization. The consequences of this type of femoral artery compromise can be severe and include loss of oxygen-rich blood flow to the leg (possibly necessitating amputation), pain while walking, differences in the length of the two legs, and an inability to use the femoral artery as the access site for future cardiac procedures.

The investigators analyzed data from the CCISC registry on a total of 8,958 instances in which the femoral artery was used as the access site for passing a catheter through the arteries and into the heart. They defined femoral artery compromise as an obstructive blood clot that required treatment with clot-dissolving medication, an interventional procedure, or surgery.

Overall, investigators observed a very low rate of femoral artery compromise (1.1%); however, small infants were at significantly increased risk. When infants weighing less than 12 kg were compared to children weighing more than 18 kg, the risk of femoral artery compromise was 6.3 to 7.6 times as high. Children who had an interventional procedure—rather than simply undergoing diagnostic catheterization—faced double the risk of femoral artery compromise. In addition, the risk was 6.4 times higher if a closure device was used at the arterial puncture site, as compared to the use of manual pressure alone to stop access site bleeding.

On the other hand, when a hemostatic patch was used to seal the wound, the risk of femoral compromise was reduced by approximately two-thirds compared with manual pressure alone. Hemostatic patches are made of a variety of materials that encourage blood cells to plug the puncture site by speeding up formation of a scab on the wound.

In addition, among infants weighing less than 12 kg, the risk of femoral compromise was cut by more than two-thirds when a very slender 3-F sheath and catheter was threaded through the femoral artery, rather than the most commonly used 4-F size.

“The true rate of femoral artery compromise is probably underestimated,” noted Dr. Forbes, “despite all the efforts to document this serious complication in multicenter registries. That’s because physicians typically identify lack of blood flow through the femoral artery by checking for the loss of a pulse in the leg. However, using this method, many blood clots go undetected.”

In the SCAI press release, Dr. Forbes commented, “We found that small infants are at particularly high risk. Because infants with complex heart disease require multiple catheterizations, avoiding obstruction of the femoral artery is critical.” He added, “The challenge is that there is no standardized diagnostic approach to pulse loss after femoral arterial access. We think it’s very important to use Duplex ultrasound to diagnose a blood clot in the femoral artery in a timely fashion.” Dr. Forbes is Director of the cardiac catheterization lab at Children’s Hospital of Michigan and Professor of Pediatrics at Wayne State University in Detroit, Michigan.