Case series in The Journal of Heart and Lung Transplantation discusses how 3D imaging software helps make more patients eligible for the life-saving SynCardia Heart implant even if they don’t meet minimum fit criteria.
TUCSON, Ariz., November 4, 2014 /3BL Media/ – A 19-year-old woman was successfully implanted with the SynCardia temporary Total Artificial Heart and bridged to a donor heart transplant after cardiac surgeons used 3D virtual implantation to determine she was fit-eligible for the procedure, according to a case series in November 2014’s The Journal of Heart and Lung Transplantation. The case series evaluated four other patients for virtual implantation with one other meeting virtual fit criteria despite failing standard criteria.
Standard fit criteria for use of the SynCardia Total Artificial Heart include a minimum body surface area (BSA) of 1.7 m2 and an anteroposterior distance greater than 10 cm from the sternum to the 10th thoracic vertebra (T10).
“On the basis of these criteria, most pediatric and small adult patients are excluded from [SynCardia Total Artificial Heart] placement,” says the report, “Virtual implantation evaluation of the total artificial heart and compatibility: Beyond standard fit criteria” (Vol. 33, Issue 11, Pages 1180-1183), authored by doctors from the Cincinnati Children’s Hospital Medical Center, The Heart Institute, in Ohio.
The case series, which includes videos of virtual implantation, was authored by Drs. Ryan A. Moore, Peace C. Madueme, Angela Lorts, David L.S. Morales and Michael D. Taylor.
The 19-year-old patient had a history of kidney cancer and developed anthracycline-induced cardiomyopathy, which was treated with a heart transplant. After several episodes of organ rejection, she developed restrictive cardiomyopathy.
The rejected donor heart had to be removed, so a left ventricular assist device (LVAD) or a biventricular assist device (BiVAD), both of which help the native heart pump blood, could not be used. The only option left for her survival was the SynCardia Total Artificial Heart.
However, the patient did not meet the standard fit criteria for the SynCardia Total Artificial Heart implant. Her BSA was 1.64 m2 and the T10-sternum distance was 8.9 cm.
Surgeons decided to use virtual implantation to see if the implant might still be successful. This reveals any issues with compression of intrathoracic structures such as systemic and pulmonary veins, the aorta, lungs and diaphragm.
“An accurately scaled three-dimensional (3D) surface rendering of the [SynCardia Total Artificial Heart] was placed within a 3D reconstruction of the chest to assess for proper fit,” the case series says. Doctors found that for this patient “proximity measures noted minimal concern for compression of pertinent structures.”
The female was successfully implanted with “no compression-related post-operative complications,” the series says. Once she was clinically stable, the patient was transitioned to the Freedom® portable driver, which provides nearly unlimited mobility. She was discharged from the hospital to wait for her donor heart at home and in her community.
After 14 months of support from the SynCardia Heart, she was successfully bridged to a matching donor heart transplant.
The paper outlines four other instances in which virtual implantation allowed surgeons, patients and their families to make informed decisions based on potential implant complications discovered in the virtual pre-operative implant procedure.
“With increasing use of [mechanical circulatory support] devices in adolescent and young adult patients, virtual compatibility testing allows for improved eligibility despite failing standard fit criteria,” the series concluded.
The technology also can help establish compatibility criteria for a smaller 50cc SynCardia Heart, for which SynCardia Systems, Inc., is working with the FDA to conduct a clinical study. Once results of that study are approved by the FDA, the 50cc, together with the 70cc SynCardia Heart currently in use, would make the SynCardia Total Artificial Heart available for almost all adults and most adolescents. The group at Cincinnati Children’s is putting together a case series evaluating the potential of virtual implantation utilizing the 50cc device in patients with a BSA less than 1.7 m2.
Caution: the 50cc SynCardia Total Artificial Heart is an investigational device, limited by federal law to investigational use.