Medical Device Daily Senior Staff Writer

The renal denervation space is getting to be as crowded as a Wal-Mart Supercenter on a Saturday, as more companies go after the market that is expected to grow to $2 billion by 2020. But the clear leader in the space is Medtronic (Minneapolis), which is already working on a next-generation version of its Symplicity renal denervation system.

Medtronic acquired the Symplicity system through its $800 million purchase of Ardian (Mountain View, California) nearly two years ago (MDD, Dec. 1, 2010).

At the Transcatheter Cardiovascular Thereapeutics (TCT) meeting in Miami late last month, the med-tech giant said it has completed the first phase of a feasibility study of its next-generation renal denervation system featuring a simultaneously firing multi-electrode catheter and advanced radio frequency generator. At least nine patients have already been treated with a 100% acute success rate in accessing the vessels and delivering therapy, the company said. The next-generation Symplicity system is not yet available anywhere in the world.

Martin Rothman, MD, VP of medical affairs for Medtronic's coronary and peripheral vascular business, based in Santa Rosa, California, told Medical Device Daily that the next-generation system picks up on both things that the company internally thought needed to be enhanced and also some recommendations from physicians who have used the first-generation Symplicity device.

"What we have been seeing in Europe is physicians are treating more complex patients and are having different requirements so we've come up with a newer device . . . to provide more opportunity for physicians," Rothman said.

Renal denervation modulates the output of nerves that line the walls of the arteries leading to the kidneys. The targeted nerves are part of the sympathetic nervous system, which has been found to play a central role in blood pressure regulation.

Perhaps the most significant change from the first-generation device to the second-generation Symplicity is that the latter features a four-electrode catheter. Rothman explained that the customer will be able to switch off electrodes so that they can use any electrode or combination of electrodes they want, in order to control where and how the treatment is delivered.

The new catheter will be 6 Fr compatible and highly conformable with a non-occluding design, according to Medtronic.

Another enhancement that physicians can expect from the next-generation Symplicity is that it adopts a spiral configuration, Rothman said, providing more opportunities for the types of arteries that can be treated with the device.

And finally, the company has changed some of the power considerations with the intention of reducing the treatment time from two minutes per treatment site to one minute per treatment site.

The issue of procedure time was a concern physicians shared at TCT. One doctor in particular, Horst Sievert, MD, from Frankfurt, Germany, discussed his vision of a "dream device" for renal denervation and said that an ideal device would be easy to use and would be easy to navigate inside renal arteries, which are not always straight.

He also noted that with his dream device the procedure time would be reduced to about five minutes total, compared to using the current Symplicity from Medtronic which, Sievert says, can take up to 45 minutes total (MDD, Oct. 26, 2012).

"I've personally done cases in the past," Rothman said. "Time is an issue, but it's really not that long of a procedure usually."

The new design should also help to alleviate some of those physician concerns as it is intended to provide ease of deliverability and consistency of RF energy application, while also enabling the treatment of a wide range of renal anatomies, Medtronic noted.

The next-generation Medtronic renal denervation system also incorporates a new generator with an improved user interface, the company said. The new generator will leverage the benefits of Medtronic's Symplicity treatment algorithm with its built-in safety features and will be compatible with both the single-electrode Symplicity catheter and the next-generation multi-electrode catheter, Rothman said.

"Renal denervation is an important advancement in the management of treatment-resistant hypertension," said Robert Whitbourn, MD, professor/director of the cardiac cath labs & coronary intervention at St Vincent's Hospital (Melbourne, Australia) and principal investigator of the study. "This next-generation system has several innovative features that could take this procedure to the next level by providing the flexibility to treat a wide range of different anatomies, as well as helping to improve efficiency of care through significantly reduced ablation and procedure times."

Rothman said the new system is "very intuitive" in that it is delivered over a wire and goes in like an ordinary angioplasty balloon so it is much more akin to what interventional cardiologists use every day. "The learning curve is likely to be extremely short," he said.

Medtronic's single-electrode Symplicity renal denervation system has been used for five years to treat more than 5,000 patients with treatment-resistant hypertension worldwide. The single-electrode Symplicity system's catheter and generator and algorithms were carefully and specifically developed through years of clinical experience to enhance the safety and effectiveness of the renal denervation procedure, the company noted.

"We look forward to moving forward with our clinical evaluation of this next-generation system that aims to augment our portfolio by offering more sophisticated features that should benefit both physicians and patients," said Sean Salmon, senior VP and president of coronary and renal denervation at Medtronic. "This feasibility study represents Medtronic's commitment to providing physicians with a broader range of solutions for performing renal denervation and to collaborating with physician partners in the ongoing evaluation of this ground-breaking therapy."

Amanda Pedersen, 912-660-2282;

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