Robot-Assisted PCI Safe, Reduces Operator Radiation Exposure

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A robotic system that enables clinicians to perform percutaneous coronary intervention (PCI) by remote control shows a high level of safety while drastically reducing operator exposure to radiation. Results from the PRECISE trial were released Thursday, May 10, 2012, at the Society for Cardiovascular Angiography and Interventions (SCAI) Scientific Sessions in Las Vegas, NV.

First-in-man results with the technology were published in the April 2011 issue of JACC: Cardiovascular Interventions.

For the Percutaneous Robotically Enhanced Coronary Intervention Study (PRECISE), Giora Weisz, MD, of Columbia University Medical Center (New York, NY), and colleagues used the CorPath 200 robotic system (Corindus, Natick, MA) to treat 164 patients undergoing elective PCI at 9 US centers. The system consists of 2 main components:

  • A remote interventional cockpit that is radiation-shielded and can be placed anywhere in the cath lab
  • A bedside unit that delivers and manipulates coronary guidewires, balloons, and stents using a robotic arm under operator direction

An average of 1.1 stents were implanted per patient, with post dilatation needed in 20.1%. Procedure time using the robotic system was 24.4 minutes, with fluoroscopy time of 11.1 minutes and contrast media volume of 144.2 ml. There were no device-related complications.

Few Adverse Outcomes, Reduced Radiation

Device success, defined as advancement and retraction of all PCI devices without conversion to manual operation, was achieved in 98.8% of patients, with 2 patients who required conversion to manual PCI. Clinical success, defined as less than 30% residual stenosis in the target lesion at the completion of the procedure and no MACE at 48 hours post procedure or hospital discharge, was attained in 97.6% of patients.

Four MACE events occurred (2.4%), all non-Q-wave MIs. There were no instances of in-hospital death, Q-wave MI, TVR, or stent thrombosis. Results were identical at 30 days.

Radiation exposure to clinicians operating the robotic system was 0.98 µGy, compared with an exposure at the procedure table of 20.6 µGy (P < 0.0001), amounting to a 95.2% reduction.

“This pivotal multicenter study with a robotic-enhanced coronary intervention system, demonstrated the safety and feasibility of the system,” Dr. Weisz and colleagues note. “The robotic remote-control procedure demonstrated technical and clinical effectiveness comparable to manual operation. In addition, the operator exposure to radiation was significantly lower.”

Once Around the Block

Morton J. Kern, MD, of the University of California, Irvine (Irvine, CA), attended SCAI and had the opportunity to take the CorPath system for a simulated test drive. “The device was set up, and I could move it and rotate it from the cockpit,” he told TCTMD in a telephone interview.

He described the system as “very comfortable to sit in and manipulate. The wire turns precisely for the most part and it goes where you direct it, and you can follow it with a balloon. It’s also got a precise millimeter pullback technique.”

The experience helped alleviate Dr. Kern’s concern that he might not be able to react quickly in case of an emergency. “It’s the fear that I wouldn’t be able to get to the patient and do something,” he said. “But it’s set up so you’re sitting down in lead with sterile covers on the joy sticks. If something happens, you can [get] up and walk into the room and quickly disconnect the machine so you’re back in business.”

Dr. Kern agreed that the radiation exposure was low and characterized the complication rates as “negligible” in the simple lesions attempted.

Worth the Money?

However, at a ballpark cost of between $200,000 and $500,000 per system, “the question is, what price are you going to pay for this reduction in radiation and the comfort factor for the operator?” Dr. Kern asked. “If money is not an object and it works perfectly, that’s fine.”

In addition, while the robotic system performed well in simple lesions, Dr. Kern expressed doubt as to whether it would be of real clinical benefit in such patients. “I can do [a simple procedure] with minimal fluoro and minimal contrast, and in the time it takes me to set up the device, I’m already across with the wire and down with the balloon,” Dr. Kern said. “In theory, this would be better for complex procedures where your radiation exposure is longer, but it’s not tested there yet. Otherwise, for simple procedures, I think it’s a lot of money for not a lot of gain.”

Dr. Kern did acknowledge the substantial reduction in radiation exposure, even in simple lesions. Still, “is [the current] degree of radiation causing a lot of problems?” he asked. “We do this every day and nobody’s dying. There are reported cases of cancer, but it’s rare.”

Overall, Dr. Kern seemed unconvinced that interventionalists would be eager to adopt the technology, especially in light of the expense. “[We] like to pass wires and pop balloons, that’s what we do,” he said. “Like all these technologies, it has to be evaluated in a cost-conscious environment.”

Study Details

The mean patient age was 64.1 years, and most patients were male (74.4%). There were also high rates of hypertension (86%), hyperlipidemia (88.4%), prior MI (60.6%), and prior PCI (78.7%). The mean LVEF was 54.9%. To participate in the trial, patients had to have a de novo stenosis of 24 mm in length or less, able to be covered by a single stent with 2 mm margins, and a reference vessel diameter of 2.5 mm to 4.0 mm.

Six- and 7-Fr guide catheters were used along with a 0.014-inch guidewire.

Note: Dr. Weisz and several coauthors of the study are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD.

 


Source:
Weisz G. Final results; Robotically-enhanced PCI: The PRECISE multicenter pivotal study. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; May 10, 2012; Las Vegas, NV.

 

 

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Jason R. Kahn, the former News Editor of TCTMD, worked at CRF for 11 years until his death in 2014…

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Disclosures
  • Dr. Weisz reports no relevant conflicts of interest.
  • Dr. Kern reports serving as a consultant for St. Jude Medical and Volcano.

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