UT Southwestern Medical Center has long been a leader in the advancement of mechanical support devices for end-stage heart failure, participating in the REMATCH, Bridge-to-Transplant, and Destination Therapy trials that measured the effectiveness of the newest left ventricular assist devices (LVADs). Now, UTSW is further advancing the field as one of only a handful of medical centers in the nation – and the only one in North Texas – to implant biventricular assist devices (BiVADs) using an innovative surgical procedure.
Nationally, ventricular assist device surgeries now exceed heart transplants, and approximately 90 percent of devices implanted are LVADs. But for a small population of patients – 5 to 10 percent – heart ailments are not limited to the left ventricle; the right ventricle needs help as well. That’s when BiVADs and UT Southwestern’s surgical procedure come into play, according to Dan Meyer, M.D., UTSW’s Director of Mechanical Assist Devices.
“The only options for patients who are suffering from biventricular failure are a transplant or some kind of biventricular mechanical support,” Dr. Meyer says. “Unfortunately, artificial hearts are not universally durable or particularly user-friendly. Another option includes external pumps, but they employ older technology and require a bulky power source, so they’re not practical long-term solutions either. That leaves a third option – BiVADs – which UTSW is in the forefront of using by adopting an innovative surgical approach.”
BiVADs: Support for Both Ventricles
Currently, there are no practical Food and Drug Administration-approved BiVADs, though UTSW hopes to participate in clinical trials of a device in 2014. Until then, Dr. Meyer and fellow UTSW surgeon Brian Bethea, M.D., are treating patients in need of extended biventricular support with a relatively new procedure that implants LVADs on both ventricles – left and right. In a manner of speaking, Drs. Meyer and Bethea are turning an LVAD into an RVAD to create a BiVAD.
In a manner of speaking, Drs. Meyer and Bethea are turning an LVAD into an RVAD to create a BiVAD.In a manner of speaking, Drs. Meyer and Bethea are turning an LVAD into an RVAD to create a BiVAD.
“It’s kind of complicated,” Dr. Meyer says of the procedure. “Left- and right-side ventricles are different sizes, so we have to modify the LVAD for use on the right side. Also, while the left-side graft goes to the aorta and the graft on the right side attaches to the pulmonary artery, the VAD has to be specially tapered so it doesn’t provide too much blood to the right side of the heart and overflow the lungs. Even the RPMs of the devices have to be set differently on the left versus the right side.”
Patient management is complicated as well, Dr. Meyer says, noting that patients must have two pumps and two controllers, rather than just one. And cost can be an issue since not all Medicare intermediaries will pay for the surgery. Nonetheless, he says, the procedure does offer another treatment option to very sick patients who perhaps are truly out of options.
“In the past, patients with end-stage biventricular failure may not have been referred because there weren’t great options short of transplantation,” he says. “But now at UT Southwestern, because of our growing experience with this new procedure, we’re able to provide this to select patients until newer devices designed specifically for the right side can be tested in a trial setting.”
The new procedure, he adds, “is an innovative application of well-tested technology.”
And Now ... Minimally Invasive LVADs
“We have innovative solutions for a whole range of end-stage heart failure conditions that allow us to meet the needs of patients who wouldn’t be able to be cared for anywhere else in this region,” says Dr. Meyer. “We have every kind of potential option.”
Those options now include minimally invasive LVAD procedures. Drs. Meyer and Bethea performed what is believed to be the first minimally invasive LVAD implantation surgery in North Texas, and they have repeated the procedure in several more patients with good results.
“We’re very excited about minimally invasive LVADs because we think it may be a better option for a lot of patients,” says Dr. Bethea, who credits the high degree of teamwork at UTSW for the achievement. “We use our vast experience with LVADs, as well as our experience with transapical transcatheter aortic valve replacement and minimally invasive valve procedures, to perform two small thoracotomies, each approximately 6 cm, which spares the sternum. We’re optimistic this approach will make the heart transplant procedure easier when the time comes.”