Complex Biventricular Repair Program
The Boston Children’s Hospital Complex Biventricular Repair Program provides an option for normal two-ventricle circulation in certain newborns and children with complex cardiac anatomy, who might otherwise undergo single ventricle palliation.
This innovative technique uses catheter and surgical interventions to perform ventricular recruitment and ultimately create a heart with two pumping ventricles.
“In some patients, the biventricular repair is done as the initial procedure. In others, we do the procedure in several steps,” says Sitaram Emani, MD, director of the Complex Biventricular Repair Program at the Heart Center. “The exact type and number of surgeries and procedures each child needs to achieve this repair varies depending on the child’s heart condition and his or her unique heart anatomy.”
The Heart Center’s depth of expertise in complex biventricular repair
Treating more of these complex pediatric patients than any other institution in the world, the program offers a customized second opinion evaluation and care plan.
At the weekly Complex Biventricular Repair conference, a highly-specialized team of pediatric cardiologists, cardiac surgeons, cardiac anesthesiologists, cardiac critical care specialists and nurse practitioners assess children who often would not be candidates for biventricular repair at other hospitals. They review patients currently at Boston Children’s, as well as those sent to us from other institutions, to determine if they might be candidates for biventricular repair.
Each child’s heart is unique, and not all patients are candidates for biventricular repair. It is a complex process and there are risks involved with this type of approach, which is why this dedicated team of specialists evaluates and monitors each patient on a case-by-case basis.
Some of the heart conditions the team may be able to treat include:
- borderline small left heart with hypoplastic left heart syndrome (HLHS)
- borderline small right heart or hypoplastic right heart syndrome (HRHS)
- unbalanced atrioventricular (AV) canal
- double-outlet right ventricle (DORV)
- complex forms of transposition of the great arteries
- pulmonary atresia with ventricular septal defect (PA-VSD) and major aortopulmonary collaterals
- complex intracardiac anatomy (straddling or criss-cross AV valves)
Advanced medical imaging for complex biventricular repair
When children have a complex heart condition, it is critical to create an accurate roadmap to determine the optimal treatment plan.
“Our imaging center is unique in the application of three-dimensional echocardiographic imaging to guide surgical planning and to evaluate the success of the surgical repair,” says Gerald Marx, MD, director of ultrasound imaging research. “In conjunction with advances in imaging processing developed at our center, three-dimensional echocardiography is used for clinical research studies to develop improved strategies of surgical repair and to evaluate both short- and long-term outcomes.”
Three-dimensional echocardiography, cardiac MRI and CT scanning at Boston Children’s have been tailored to optimize diagnosis and monitoring of patients treated by the program.
“While the results of these efforts continue to evolve, our patients are already benefiting from these advanced imaging techniques,” says Emani. “Based on the unique characteristics of each child’s heart, our specialized team uses the most advanced imaging technology available to determine a customized approach for each child and monitor the progress of his or her ventricular recruitment.”
The Complex Biventricular Repair Program is constantly researching new, innovative ways to improve outcomes and offer the option of complex biventricular repair to more children with single ventricle defects.
“Close alignment with the valve program has led to development of advanced valve repair and replacement techniques, including expandable valve technology,” says Emani. “Adjunctive therapies such as stem cell therapy to improve results of recruitment are being developed as well.”
A sampling of current research:
- 3-D printing of the heart
Pediatric cardiologists and surgeons at Boston Children’s have developed a program to use 3-D printing technology to create models of each child’s heart based on imaging tests. These models are used to aid surgical planning prior to entering the operating room and help explain procedures to family members. Emani and his colleagues in the Department of Cardiac Surgery believe use of these models will reduce time in the OR and can help improve outcomes. They hope to prove this in a formal clinical trial. The goal is for insurance companies to pay for 3-D printed heart models, and the first step toward that end is gathering data. The trial will begin with a pilot study of 20 patients diagnosed with double outlet right ventricle (DORV), as this disease’s intricately complex and highly variable cardiac anatomy makes it ideal for modeling with 3-D printing.
- Mesoblast stem cell therapy for patients with single ventricle and borderline left ventricle
Emani is the principal investigator on this clinical trial to learn if mesenchymal precursor cells (MPCs) injected directly into the left ventricle can help promote growth of the ventricle. It is believed that injection of MPCs will help improve the chances of those patients with single ventricle or borderline left ventricle (LV) being converted to biventricular circulation, which could improve their quality of life and longevity over palliation.
This study is enrolling patients under the age of 5, with a diagnosis of hypoplastic left heart syndrome (HLHS), unbalanced atrioventricular canal (AVC) or borderline left heart who are undergoing staged LV recruitment following bidirectional Glenn (BDG) or undergoing BDG with plans for LV recruitment. Those patients enrolled in the study will be randomized to either the experimental arm or control arm of the study. Patients randomized to the experimental arm will receive MPCs injected directly into the LV endocardium during their LV recruitment or BDG procedure. Those patients randomized to the control arm will receive normal standard of care during their procedure with no injection of MPCs.
- Virtual surgery to model an individual patient’s response to biventricular repair
Making the decision to undergo biventricular repair or conversion can be difficult given individual patient differences. Complex computer modeling developed by engineers within the program is being used to help determine how each individual patient will respond to surgery in terms of blood pressure and heart function – factors that determine success of biventricular repair. Using data collected from catheterization, MRI and echocardiogram, “virtual surgery” is performed in silico.