New Method To Combat Congenital Heart Disease in Children

A unique set of computer modeling tools for studying fluid dynamics are expected to enhance pediatric surgeons' ability to perform critical heart surgery on children.

Researchers at the University of California San Diego (UCSD; USA) developed the fluid dynamics simulation tools to provide a way of testing new surgery designs for single ventricle defects (SVDs), a severe form of congenital heart defects that leave a patient with only one functional heart-pumping chamber. SVDs are uniformly fatal if left untreated, and require a patient to undergo multiple heart surgeries, which generally end with a Fontan procedure, in which a modified T-shaped anastomosis junction is formed between central veins and arteries, sending deoxygenated blood to the lungs. This bypasses the heart on the one side so that the resulting circulation puts the single pumping chamber to optimal use. Using models derived from magnetic resonance imaging (MRI) image data, the researchers optimized a Y-Graft model for the Fontan baffle used in the procedure that can help pediatric surgeons determine whether this procedure will benefit a patient, as well as determine how a patient's heart will perform during moderate exercise. This provides the patient with better long-term cardiac performance and better exercise tolerance, particularly during the teenage years and early adulthood, when conventional-type Fontan procedures begin to fail. An advantage of the proposed Y-Graft design is that it can be optimized or modified for an individual patient by custom manufacturing the graft portion prior to surgery. The study describing the simulation procedure was published in the February 2009 issue of the Journal of Thoracic and Cardiovascular Surgery.

"These simulations allow us to obtain information that is difficult to measure in the clinic. This way we can design something that would allow a patient to perform well at rest but also during exercise,” said lead author Alison Marsden, Ph.D., an assistant professor of mechanical and aerospace engineering at UCSD. "Our goal is to provide a set of personalized tools that can be used in collaboration with surgeons to identify the best procedure for patients.”

"The whole concept of simulation based medicine offers opportunities to try things with zero risk to the patients. With this type of computer modeling, you can do 100 simulations before you ever try it in a patient,” said Jeff Feinstein, M.D., an associate professor of pediatric cardiology at Stanford University (CA, USA) who plans to use the Y-Graft computer models for a Fontan procedure for the first time during 2009.

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University of California San Diego
Stanford University