Congenital Heart Surgery Laboratory

 

This laboratory is principally interested in investigation of issues related to congenital heart surgery. Because of the multidisciplinary nature of this field and in order to enhance the relevance and quality of the research performed, the laboratory benefits from the participation of faculty from pediatric cardiac surgery, pediatric cardiac anesthesiology and critical care medicine, and pediatric cardiology. Surgical residents interested in working in this laboratory will be principally under the supervision of Dr. James Jaggers Pediatric Cardiac Surgery.

 

The laboratory is extremely active in a number of areas and can accommodate up to 3 surgical research fellows at a time. Most of these fellows have come from the Duke surgical residency program, but fellows from abroad have played an active role in the past and can be an integral part of the laboratory. Their presence can broaden the perspectives of the Duke residents. The laboratory meets as a group and projects are evaluated as they proceed by all members of the multidisciplinary group. Participation from medical students is also encouraged and several previous medical students have had an opportunity to present their work at national meetings. Team values and cooperation are emphasized and it is expected that members of the laboratory work with each other and share in each other's success.

 

The facility is fully equipped to perform studies employing cardiopulmonary bypass (or ECMO on pigs, dogs and sheep. It is expected that research fellows will learn a variety of surgical skills (by virtue of having to perform the complex surgical preparations necessary to place small piglets on bypass), analytic methods (necessary to accurately interpret data), and general lab attributes such as ability to review previous work performed in their selected area of interest, ability to determine how to best design a study and what questions that study can answer and how to carefully acquire data so that meaningful and realistic conclusions will be reached. The lab offers research possibilities in a number of areas, and given the multiple interests and talents of the entire group, almost any issue pertaining to the treatment of congenital heart disease can potentially be addressed in this environment.

 

Cerebral Protection of Neonates

 

This issue has emerged as one of the most important topics in congenital heart surgery. As infant heart repair is performed on an increasing number of neonates and young infants, with impressive success, the long-term outcome for these patients with respect to their neurologic development (quality of life) has taken on renewed importance. Many cardiac surgical procedures on infants are performed using profound hypothermic cardiopulmonary bypass -- often with periods of low flow or total circulatory arrest. Our group has become one of the leaders in clinical and laboratory investigation of the response of the neonatal brain to methods of cardiopulmonary bypass and work from this lab has already had an impact on determining the best strategies to limit brain injury during cardiac surgery on infants. These studies are performed by placing neonatal animals on bypass. They overlap nicely with parallel studies performed on patients in the clinical setting and lab fellows are encouraged to become involved in those studies as well. Work from this laboratory has been presented at the American College of Surgeons, American Association of Thoracic Surgeons, Society of Thoracic Surgeons, World Congress of Pediatric Cardiac Surgery, American Heart Association, American College of Cardiology and others.

 

Neonatal Myocardial Protection

 

It seems increasingly clear that the infant heart responds to ischemia differently than the adult heart and the laboratory is dedicated to investigation of optimal methods to protect the infant heart during surgical repair. Most studies are now performed on in vivo animals (as opposed to an isolated heart model) with the animal on CPB since this most closely reflects the clinical situation. These studies employ sophisticated methods of evaluating ventricular function and some studies require substantial surgical skill for creation of the models. Work in this area has been presented at the American College of Cardiology, Society of Thoracic Surgeons and the American Heart Association.

 

Pulmonary Injury from Cardiopulmary Bypass

 

The effect of cardiopulmonary bypass on pulmonary function has emerged as an area of increasing clinical interest. Babies can demonstrate varying degrees of pulmonary dysfunction following open heart surgery and this can substantially prolong their post-operative recovery. The role of inflammatory mediators in this process is currently under investigation in the lab and strategies for protecting the lungs during and after CPB should be developed. Work from this area is performed in collaboration with other subspecialists and has been presented at the Society of University Surgeons, the Society of Thoracic Surgeons, and the American College of Surgeons.

 

ECMO

 

The Duke ECMO (ExtraCorporeal Membrane Oxygenation) program is one of the nation's largest and our laboratory serves as the site for all animal training for the ECMO team. We take advantage of this by performing a number of investigations related to current controversies in ECMO. This laboratory interest underscores the necessity for those who seek a career in pediatric heart surgery to intimately and thoroughly understand cardiopulmonary bypass physiology and technology. Work from the ECMO lab has been a highly regarded addition to the national ECMO meetings.

 

Fetal Cardiac Surgery

 

As cardiac surgery continues to move towards younger and smaller patients, it is possible that certain procedures will be performed on human fetuses. Fetal surgery is already a clinical reality, but fetal cardiac surgery is currently limited by several factors. One of these is the lack of knowledge about how to safely perfuse a fetus. We hope to begin investigation in this area in the near future.

 

Other Areas of Interest

 

There are several other areas of current (and past, but not forgotten, interest) which include: shunt physiology (presented at the American College of Surgeons), cardiopulmonary interactions (the impact of various forms of ventilation on RV afterload and on pulmonary impedance), and the effects of nitric oxide and PFC (liquid lung ventilation) on lung function following CPB.

 

Surgical residents interested in a career in congenital cardiac surgery and who would like to learn more about current laboratory projects should contact Dr. Jaggers.