(From Pediatric Directions, Issue 38)
In December 2010, surgeons in Nationwide Children’s Heart Center program made history, by performing the first successful bloodless heart transplant on one of the youngest patients recorded. What makes Nationwide Children’s Blood Conservation program unique is the goal of a bloodless surgery every time. The central piece of technology that makes this possible is the heart-lung bypass machine. The standard bypass machine is constructed for adult patients. When a patient’s blood comes in contact with the standard size machine, it is coming in contact with foreign material, which makes up the bypass circuit. This can have profound consequences on an infant or child, whose bodies often become very swollen.
The Heart Center team modified the size of many of the components that make up the machine. By making the components smaller, the exposure to foreign material was minimized, and the inflammatory response from the patient reduced, providing improved outcomes.
Importance of Blood Conservation
The Heart Center team prepares for bloodless surgery long before the procedure takes place, by implementing protocol such as:
In addition to heart surgeons, it takes an entire team of specialists, which includes perioperative nurses, cardiologists, intensivists, anesthesiologists and perfusionists, who all work integrally and systematically to achieve a successful bloodless outcome. With the depth and breadth of experience, the team knows to use only the exact amount of anesthesia the patient’s body requires, so the patient can be safely removed from the ventilator as quickly as possible.
The pediatric specialists are aware of the need to keep body temperatures at the appropriate level to promote healthy clotting.
Understanding that every detail in delivery of care matters, team members have modified the equipment for use on the pediatric patient. The central piece of technology that is used is the heart-lung bypass machine. The standard bypass machine that was used for years was “one size fits all.” As a result, there were complications that began to surface when the standard bypass machine was used on pediatric patients.
The smaller the patient is in relation to the size of the bypass machine, the more profound the interaction between the machine and the body, and the more profound the dilution.
Everything in the body gets diluted by the volume of the bypass machine. When a patient’s blood comes in contact with the bypass machine, it’s coming in contact with foreign material in the tubing, the artificial kidney, the artificial lungs and the filters. The result for the patient is a total-body inflammatory response. This can have profound impacts on an infant or child, whose bodies often become very swollen. Their immune system and their blood coagulation systems are altered.
The Heart Center re-evaluated the heart-lung bypass machine, which had been developed as a “one size fits all,” primarily to accommodate adults. To limit the volume of a patient’s blood that is exposed to foreign material, smaller diameter tubing is used. Pictured above are the five diameter sizes of tubing available to accommodate specific patient size and need, ranging from 1/8" up to 1/2" diameter.
The Heart Center team has made adaptations to the heartlung bypass machine to help minimize the exposure to foreign materials for the pediatric patient. By modifying the pieces of equipment, such as the diameter of the tubing that transfers the patient’s blood to and from the machine, the inflammatory response from the patient’s body has been reduced. (See photo of various sizes of tubing for heart-lung bypass machine above).
The Heart Center re-evaluated the heart-lung bypass machine, which had been developed as a “one size fits all,” primarily to accommodate adults. To limit the volume of a patient’s blood that is exposed to foreign material, smaller diameter tubing is used. Pictured above are the five diameter sizes of tubing available to accommodate specific patient size and need, ranging from ?" up to ½" diameter.
Committed to Providing Bloodless Heart Surgery
The Heart Center team is committed to optimizing all aspects of heart surgery that support blood conservation. Although transfusions are still mostly safe and are needed in many cases, the team at Nationwide Children’s would like to see more surgeons strive to treat patients with as few transfusions as possible. The families of many of the patients that come to Nationwide Children’s have been told that it’s impossible to do a bloodless heart procedure, which is why The Heart Center team is committed to carrying out the steps needed to make it possible.
Strategy for Providing a Bloodless Heart Transplant
Typically, patients like Andrew, may get one to two blood transfusions before surgery, one to two during surgery and at least one transfusion after surgery to ensure an adequate supply of blood. However, studies show that the transfusions can double the risk of infection, increase costs and lead to higher morbidity rates than the bloodless approach.1
Pre-Surgery: Although The Heart Center team realizes the sooner the child’s heart can be repaired the better he/she will be in the long run, heart transplants cannot be scheduled. So everyone strives to manage the pediatric patient’s body so it is as strong as possible and prepared to undergo major surgery. Data exists demonstrating that undue anemia exacerbates heart failure, therefore while awaiting a donor heart, the specialists on The Heart Center team know it is imperative to attempt to conserve blood draws and optimize medical management.
The commitment to the bloodless process begins even before surgery is possible, and often poses challenging medical decisions, such as avoiding blood transfusions. However, providing blood transfusions carry their own risks. Certainly the risks are low, but they are not zero. Red cell products, although safer with respect to viral transmission with contemporary blood banking techniques, are still associated with morbidity. For example, ABO incompatibility, allergic reaction and transfusion related acute lung injury or volume overload may occur. In addition to these obvious potential adverse reactions, the efficacy and immune modulation of red cell products must be questioned and evaluated. Studies concerning stored red cell products fail to show efficacy data with oxygen transport and carrying capacity. Stored products are acidic, relatively anoxic, and depleted in 2, 3 diphosphoglycerate, which is directly involved in the ability of hemoglobin to bind and release oxygen. Also, stored red cell products harbor activated inflammatory cells, humoral mediators and donor lymphocytes.
Donor lymphocytes can transiently suppress a patient’s native immune response to infection. Leukocyte reduced blood products are theorized to reduce the immune modulation, yet there are adult studies that noted no difference in the risk for perioperative infection in lieu of leukocyte reduction or not. Exposure of a transplant candidate also leads to the concern of sensitization to human leukocyte antigens. If a patient is sensitized, the risk of humoral (antibody mediated) rejection increases, and the care plan post-transplant becomes more complex.
During Surgery: It is the introduction of foreign blood and material during surgery that leads to inflammatory responses and increases not only the risk of infection, but also potential graft dysfunction. The Heart Center physicians use cell savers, which collect, clean and recycle the patient’s own blood during surgery. And each surgery is as minimally invasive as possible to reduce larger incisions and bleeding.
Meticulous techniques and smaller incisions all reduce the amount of bleeding which is the hallmark of the Blood Conservation Program.
Assessment of the procedure while still in the OR is another important strategy during heart surgery. Whether it is for a repair or a transplant, taking time to assess the procedure to be sure there are no residual issues ensures the surgery is as perfect as possible. The diagnostic testing that is done prior to the end of surgery includes echocardiograms and angiograms to confirm the team is providing the patient with the best possible outcome. These steps are also crucial to help avoid additional surgeries. Additional surgeries mean more exposure to foreign materials and greater risk for additional complications.
Post Surgery: Care is focused on allowing the patient’s own body and immune system to do most of the recovery work. As noted above, anesthesiologists have the goal of removing the heart patient from the ventilator as quickly as possible after the surgery, knowing the sooner the patient is off the ventilator, the fewer blood tests he/she will require. This approach takes team buy-in and a systematic understanding of its benefits. The process worked for Andrew, who is one of the youngest children ever to have a “bloodless” heart transplant, without a single drop of donated blood.
Andrew’s Case Study
Andrew Craver, a 6-year-old boy from New Jersey, became one of the youngest patients known to have a successful bloodless heart transplant, and at one of only a few pediatric institutions that has the resources to perform it.
Andrew was originally referred to The Heart Center at Nationwide Children’s Hospital when he was just 3 years old, for a heart transplant due to cardiomyopathy. At the time of his initial evaluation at The Heart Center at Nationwide Children’s, it was felt that Andrew could be managed as an outpatient until the time came when his clinical situation changed necessitating listing. When his symptoms began to worsen in 2010, he was referred back to Nationwide Children’s for a second transplant evaluation by The Heart Center team. During that evaluation, he was placed on the heart transplant waiting list.
The decision to proceed with a heart transplant is considered when no other medical or surgical options are available. A heart transplant offers an improved quality of life but it also comes with many new responsibilities. In Andrew’s case, a heart transplant presented the ultimate challenge to The Heart Center team for needing blood conservation, since it was known that his body was already going to react to an entirely new organ. In December 2010, Nationwide Children’s performed its first bloodless heart transplant on Andrew. The bloodless surgery was such a success that his parents say he sat up the day of surgery, walked the next day and was riding a bike within a week.
Andrew’s parents chose to come to Nationwide Children’s hospital because of The Heart Center’s Blood Conservation Program and the confidence that they had in the entire Heart Center team. The Heart Center Transplant team couldn’t be happier with Andrew’s outcome. Today, Andrew is home and back to being an active 7-year-old, full of energy.
References / Footnotes
1. History: There was a time when all surgeries were bloodless surgeries. But during World War II, the concept of transfusing blood became a standard practice that endures today. The first bloodless technique was performed in the 1960s - and hospitals that employ blood conservation strategies are somewhat rare. Noblood.org says there were only 70 in the US in 2002 – and still only about 100 in the nation today.
Mark Galantowicz, MD, is surgical director of the Heart, Lung, and Heart-Lung Transplant Programs at Nationwide Children’s Hospital. He is also the co-director of Nationwide Children’s Heart Center, chief of the Department of Cardiothoracic Surgery at Nationwide Children’s and The Murray D. Lincoln endowed chair in Cardiothoracic Surgery. Dr. Galantowicz is professor of Surgery at The Ohio State University College of Medicine. After receiving his undergraduate degree from the University of Pennsylvania, he was awarded the Fulbright Scholarship to conduct molecular biology research at the University of Geneva, Switzerland. He received his medical degree from Cornell University Medical College and completed his surgical training, including a fellowship in cardiothoracic surgery, at Columbia-Presbyterian Medical Center. His clinical interests are in the areas of cardiopulmonary transplantation and the surgical repair of newborns with heart disease. His research interests focus on the development of innovative, less-invasive strategies for the management of cardiopulmonary disease. Dr. Galantowicz is named among the “Best Doctors in America.”
Timothy Hoffman, MD, is medical director of the Heart Transplant and Heart Failure Program, and associate medical director of Cardiology at Nationwide Children’s Hospital Heart Center and an associate professor of Pediatrics at The Ohio State University College of Medicine. He is also the Pediatric Cardiology Fellowship Program Director. Dr. Hoffman recently served as co-chair of the Outcomes and Genomics Committee for the Pediatric Heart Network/NIH Perioperative Working Group and Chair of the Ohio Solid Organ Transplant Consortium. He also serves as the Pediatric Liaison to the AHA Heart Transplant and Heart Failure Committee and as the Pediatric Representative for the ACC Board of Trustees-Ohio Division. Dr. Hoffman is involved in several multicenter research collaborations focusing on heart transplant care, treatment of the failing myocardium, and cardiac support in the perioperative period. He also is an active participant and co-author for the Pediatric Heart Transplant Study Group. Dr. Hoffman is on the Board of Directors for the Pediatric Cardiac Intensive Care Society and is currently serving as Treasurer. Clinically, Dr. Hoffman focuses on transplant medicine, patients with heart failure and critical care cardiology. Dr. Hoffman is named among the “Best Doctors in America.”