Robot-Assisted PCI Shows Promise in Early Clinical Experience

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A robot-assisted angioplasty system has demonstrated safety and feasibility in a first-in-man study. The new technology also holds benefits for clinicians, whose exposure to radiation was dramatically lower than typical levels, according to a paper published in the April 2011 issue of JACC: Cardiovascular Interventions.

But in a telephone interview with TCTMD, Morton J. Kern, MD, of the University of California, Irvine (Irvine, CA), expressed skepticism about whether the technology had practical applications.

Testing Outcomes in Patients, Clinicians

Investigators led by Juan F. Granada, MD, of the Jack H. Skirball Center for Cardiovascular Research (Orangeburg, NY), evaluated the CorPath 200 robotic system (Corindus, Natick, MA) in 8 patients undergoing elective PCI at the Corbic Research Institute (Envigado, Colombia).

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

Overall, the average procedure time was 43.0 ± 18.6 minutes, including a robotic-system procedure time of 26.5 ± 8.0 minutes and fluoroscopy time of 11.5 ± 3.7 minutes. Total contrast volume used was 158.8 ± 53.8 mL per patient.

The primary endpoint of device clinical success—defined as less than 30% diameter stenosis after using the system to enable balloon delivery, stent deployment, and successful retraction without any in-hospital MACE (composite of cardiac death, MI and clinically driven TVR)—was achieved in all patients. No dissection or perforation occurred. Instrument components were successfully retrieved in all instances except 1 when a guidewire was retrieved by the robotic system to the distal part of the guide catheter but, because a partial system malfunction occurred, the remainder of the retrieval was performed manually. This misstep was not associated with any complications.

Within 24 hours of treatment, patients had no increase in CK-MB levels. There were no instances of MACE either in-hospital or within 30 days.

Notably, total radiation exposure to the operator in the cockpit was 97% lower than the levels found at the procedure table (1.81 ± 1.93 μGy vs. 61.57 ± 54.95 μGy; P < 0.012).

Both operators involved in the study rated the robotic system’s performance as equal to that of standard PCI in 92.5% of cases, including impressions of all devices and procedural steps. And in 2 cases, the guidewire advancement/retrieval steps surpassed conventional methods. As might be expected, the operators deemed the 1 case of retrieval failure as poorer than what could be achieved with a manual procedure.

Addressing Procedural Deficiencies, Occupational Hazards of PCI

“Despite the significant evolution in interventional device technologies, the actual procedural methodology and workflow in the catheterization laboratory has remained unchanged in the last 25 years,” the paper notes, adding that “[i]ncorporating a remote-control, robotic-assisted PCI system into the catheterization laboratory might address some of the procedural deficiencies and occupational hazards associated with traditional PCI in addition to contributing to a higher degree of precision and control for the interventional procedure.”

In a telephone interview, Dr. Granada told TCTMD that there is a lot of enthusiasm over robot-assisted PCI because it addresses 2 important occupational hazards for clinicians—radiation exposure and orthopedic injuries—both of which are “a big deal in interventional cardiology today.”

The system is intuitive to operate, he reported, particularly for new generations of cardiologists, who grew up around video games and different types of interactive technology. “You manage the wires and balloons with a joystick and a regular flat screen. It’s actually simple,” said Dr. Granada.

Patients may also notice that the technology positively affects their experience, he added. “Due to the fact that you [as an operator] are in full control of the room, not only the equipment but the vital signs, and you’re comfortably sitting and looking at everything, you actually have more time to talk with the patient and the staff.”

The Stuff of Science Fiction

Dr. Kern, on the other hand, had some reservations. Performing angioplasty with the technology seems feasible, he noted, but the clinician still has to be there in person for at least some of the procedure and perform some tasks manually. The robot can manipulate instruments and help operators move away from the radiation field, Dr. Kern acknowledged.

Still, he classified it as “very science fictionoid, without clinical necessity.”

While calling the technology “very interesting,” Dr. Kern seemed uncertain how it could be applied, or even where the idea for it arose. “Maybe it was designed in the days when we were doing brachytherapy, when you wanted to deliver stuff into the artery and not have the operator close by,” he said. “This might be a holdover from that era, but that field is long dead.”

Dr. Kern added that he could not see the robot system in clinical use any time soon. “I can’t imagine any operator at this minute thinking this was an advantage or saving anything, including the radiation,” he said. “And God knows if there’s a complication, you’ve got to have to scramble. You’ve got to disassemble that robot in a heartbeat.”

As for the reduction in radiation, “So what?” Dr. Kern commented. “Nobody’s dying of cancer because they’re PCI operators. There are big time operators that do 10,000 cases and they still don’t have any radiation injury, so I think it’s overblown. Obviously, lower radiation is a plus, but how much of a plus, I don’t know.” Other devices being developed, such as non-lead based radiation shielding, could also help reduce exposure, Dr. Kern proposed.

Another concern mentioned by both physicians was cost, which Dr. Granada said would be “the determinant factor in adoption of this technology.”

Extending the Scope

The current feasibility study provides evidence for use of the CorPath system in simpler PCI cases involving type A or B lesions, Dr. Granada said. But going forward “[t]he important thing is to understand the real-life clinical applicability of this technology, because obviously there are going to be some procedures in which manual and full control will be completely necessary.”

According to the paper, the use of robot-assisted PCI in more challenging anatomies including severe tortuosity or calcification or cases that necessitate multiple wires or balloons requires further investigation. Another potential application worthy of exploration is endovascular treatment of peripheral artery disease, which typically involves high radiation exposure and long, physically demanding procedures for operators, Dr. Granada said.

Corindus announced April 21, 2011, that it has joined with Royal Philips Electronics (Eindhoven, The Netherlands) to market the product. Meanwhile, the single-arm, multicenter CorPath PRECISE trial is slated to test the robot-assisted PCI system in a larger population of 175 US patients.

Study Details

The right coronary artery was treated in 4 patients, the left circumflex artery in 3, and the left anterior descending artery in 1 patient. Six of the lesions were classified as type A and 2 as type B1. Mean values for lesion length, reference vessel diameter, and diameter stenosis were 11.4 ± 6.1 mm, 3.0 ± 0.74 mm, and 63.1 ± 15%, respectively. All procedures were performed with a 6-Fr guide catheter and a single type 0.0014-inch balanced middleweight wire (Abbott Vascular, Santa Clara, CA). Predilatation was done with the Maverick 2 Monorail balloon catheter (Boston Scientific, Natick, MA). Bare-metal Liberté stents were used in 6 patients and everolimus-eluting Promus stents in 2 patients (both Boston Scientific).

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

Source:

Granada JF, Delgado JA, Uribe MP, et al. First-in-human evaluation of a novel robotic-assisted coronary angioplasty system. J Am Coll Cardiol Intv. 2011;4:460-465.

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