Traditional treatment for thoracoabdominal aneurysm requires a large incision and clamping of the aorta, which can lead to significant complications and often eliminates surgical repair options for patients due to their age or overall health. But Adam Beck, MD, director of the Division of Vascular Surgery and Endovascular Therapy at UAB, is conducting a study of devices customized to individual patient anatomy and inserted in a less invasive procedure.
"The traditional open surgery is a huge operation with high morbidity, and depending on the extent of it and the health of the patient, the mortality can be high too," Beck said. "With this device, we can do repair through incisions that are about one centimeter in each groin. Sometimes we have to put a little incision in the arm too. It's a big operation through small incisions. We are working through the inside of the blood vessel over wires on x-ray, and we never stop blood flow around and through the graft, which decreases risks."
Beck holds a physican-sponsored investigational device exemption (IDE) from the FDA for this clinical trial. "It allows me to design custom devices created to match a patient's anatomy to fix an aortic aneurysm that involves the portion of the aorta that has branches to the intestines and kidneys," he said.
Beck uses 3-D imaging to construct the customized grafts. In cases where the surgery is elective, Beck constructs a three dimensional model of the aorta and uses it to determine if the anatomy meets the criteria for this procedure. If the patient chooses to enroll in the trial, Beck designs the device and sends the plans to Cook Medical in Australia, where the device is manufactured by hand.
Patients who are symptomatic and don't have two months to wait on a device to be manufactured are often still eligible for the procedure, but Beck will develop the device himself. "I can take a device meant for a simpler repair, a straight tube, and take the device out of its packaging, modify it, and essentially create the same thing they would in Australia. This is done at the time of surgery while the patient is being put to sleep under anesthesia," he said.
Beck completed a mini-fellowship on this procedure in Holland while in training at Dartmouth 10 years ago. His current study has been ongoing for over three years, and he has completed 100 surgeries so far. He recently received approval from the FDA to implant another 100 devices.
"You are supposed to monitor for five years after you implant the devices, but clinically we follow these patients for the rest of their lives, which we hope is longer than five years," Beck said.
Beck explained that the FDA will not approve customized devices that aren't intended to be brought to market, but the surgeons who are performing this procedure are collaborating and sharing data, and there are now companies working to develop similar standard devices for more widespread use.
"They try to make a couple of configurations that will fit most patients' anatomy. Those are probably five years off," he said. "It would be ideal to have devices on the shelf, and you just pick the one that fits your patient and put it in. But there will probably always be a role for custom devices."
Although Beck has performed 100 of these surgeries under the current study, he has, over his career, performed nearly 450, and in over 300 cases he has created the device himself.
"It takes a tremendous amount of experience and skills to do this," Beck said. "And you have to have specialized imaging in the operating room. We use interoperative three-dimensional overlay imaging. In the operating room we take the same CT scan we designed the device off of, and we fuse it with their bony landmarks. It's almost like you are looking inside the patient's body and seeing the aneurysm itself on the screen. When you deliver the device, you know where the branches are, but you have to know how to use the 3-D overlay. It's complicated."
Because of the complication, there are few facilities in the U.S. performing this procedure. UAB is the only hospital in Alabama that offers this customized option. Patients in the Southeast would otherwise be referred to Florida, Texas, or North Carolina.
For physicians interested in the surgery, Beck has a 13-minute video describing the procedure at https://www.youtube.com/watch?v=U5UuXnhzWd0.