As a young resident at Cleveland Clinic in the 1970s, Dr. Juan Parodi was frustrated with the present approach to repairing abdominal aortic aneurysms (AAA). It required a traumatic open surgical procedure in which the aorta was isolated, the weakened segment often removed, and an artificial graft sewn into place. With many of the patients being elderly and suffering with co-morbidities, such an invasive open surgical procedure was risky, or impossible.
“I thought to myself, this is one of the best places in the world for these procedures, and even in this situation the results are not good sometimes,” said Parodi. “Then I conceived the idea of an endovascular approach. I had the idea of a graft to fix and fill [the aneurysm].”
His concept would eventually lead to today’s promising new, less invasive catheter-based approach. In short, it is an X-ray guided technique in which the stent-graft is placed in healthy aorta segments above and below the aneurysm, isolating the weakened segment from circulation. At the same time, the stent-graft would provide a new, normal-sized tunnel to maintain blood flow.
Parodi started his first experiments in 1976 using homemade components. The technology was crude and the results unsuccessful, but he learned that the concept was feasible. After failing to obtain the desired support for his concept at Cleveland Clinic, he returned to his homeland of Argentina.
Parodi’s experiments were on and off when he met a fellow countryman, Dr. Julio Palmaz, who was presenting initial results with stents at TCT. “I was having trouble with my stents and I wanted his, so I approached Julio. He was very kind and gave me some to take home. I used them [in 1988] and they worked,” said Parodi.
Inspired to continue his work but in need of proper stents, Parodi convinced someone who was producing missiles for Iran to start making stents for him instead. “The quality of the device was actually very good. I did more experiments and waited for the results,” he said.
After years of research, Parodi performed his first human experiment in September 1990 with the help of Palmaz. They performed two procedures, one using open surgery, the other using the endovascular approach. Benefits of a less invasive procedure were evident almost immediately. “When we checked on the patients later that day we discovered that the open patient was still intubated while the other was having dinner two hours later,” said Parodi.
Thus, the very first endovascular AAA repairs had been made possible through the imagination and determination of pioneering surgeons and innovative stent technology. But some say adequate imaging would play a significant role in the adoption of this procedure, the advancement of hybrid OR, and the survival of vascular surgery.
Adequate Imaging and Avoiding Extinction
With the success of this initial procedure, Parodi continued. Often in need of a hybrid OR environment, he wanted an imaging system of his own. “I could get one with OEC. It had very good image quality from the beginning. I told Larry‘this is a good system. Every surgeon will want one of these.’”
In 1992, Parodi performed the first endovascular AAA repair in the United States at Montefiore Medical Center with Dr. Michael Marin, an attending surgeon, and Dr. Frank Veith, chief of Montefiore’s vascular programs. In true maverick-like fashion, the surgeons found and used an old portable OEC fluoroscope that was going unused by the hospital’s cardiologists. The general surgery system was without the necessary imaging features.
“Shortly after that I determined that the OEC Mobile Hybrid OR had the image quality and the features required to enable AAA treatment with an endograft. The OEC system had the high quality imaging required to perform these procedures that were only found on fixed cath labs at that time,” said Dr. Takao Ohki, the director of the vascular surgery research laboratory who became chief of the endovascular program in 1998 and the chief, division of vascular surgery at Montefiore in 2002.
“We realized very early that imaging was everything,” said Veith. “OEC imaging was great. It was very easy to use, very easy to move, very easy to do all the things we needed. We were able to do with our OEC anything we wanted to do, and mobilize it. So we could use it in multiple rooms, and perform two to three cases at the same time.”
As an early adopter of the endovascular approach to AAA repair, Veith was very vocal on the importance of adapting and acquiring the catheter-guidewire-imaging skills to perform some of the new endovascular procedures that replace vascular operations. In his 1996 presidential address to the Society of Vascular Surgeons, Veith discussed the variety of applications ofendovascular skills, intraoperative digital fluoroscopy and catheter guidewire techniques to simplifying and improving a variety of standard vascular operations.
“Vascular surgeons from now on must use these endovascular techniques as an essential survival adaptation in a changing environment,” he stated. “Because the instrumentation is available, we must be able to use it. To do so will render us fit to survive. Not to use these techniques is analogous to flying blindly through clouds when good navigational instruments are available. It is a clear path to extinction.”
Parodi agrees. “I would also say that OEC allowed surgeons to have independence from cardiologists and radiologists who were controlling the fixed systems in the hospitals. Parodi continued by saying, “This allowed vascular surgeons to maintain control of abdominal aneurysms, and not the other specialties.”
“Without the OEC system in the OR and its ability to give the vascular surgeons an adequate imaging tool, AAA stenting would have taken much longer to be approved and may not have reached the gold standard that it is in many regions today,” said Ohki. “The ability of the OEC Hybrid OR to perform these procedures was a key factor in triggering the transition of the vascular surgery society from performing open surgery only to primarily endovascular today. You can say that OEC enabled two key trends, the growth of lifesaving technologies such as AAA stenting, and the saving of the vascular surgery practice.”