Medical Device Daily

PARIS – As cardiovascular interventionalists continue to adopt drug-eluting stent (DES) technology, and struggle with the clinical issues they raise, the field is moving on to conquer one of the largest hurdles in this arena – how to treat branching or bifurcated vessels in a safe and efficacious manner, and do so in a way that will provide a competitive challenge to open surgical procedures.

This issue essentially offers the problem of treating, via stenting, lesions in a primary vessel and a branch vessel forming a Y-shape, obviously significantly more difficult than putting a stent or stents in one vessel.

This problem in small engineering drew a standing-room-only group of attendees to one of the medium-sized rooms of the EuroPCR venue during a Thursday morning session. The topic: “Innovative and Emerging Technologies,” which in addition to bifurcated stenting also addressed catheterization via remote control and other distant hurdles to be crossed or better ways of crossing older hurdles.

Placing stents in the Y-shaped vessel configurations offers a variety of difficulties in terms of correct placement and apposition of the stent and difficulty of placing more than one stent at various angles in these small spaces, according to the presenters.

A cardiovascular surgeon once described himself to Medical Device Daily as basically “a plumber,” but the issues posed by bifurcated vessel treatment suggest that any plumber taking on this problem ought to come with a graduate engineering degree and lots of hands-on experience.

Campbell Rogers, MD, director of the cath lab at Brigham and Women's Hospital (Boston), discussed the Cappella sideguard ostium protection device for bifurcation stenting, using a self-expanding feature for anchoring and separate guidewires to access the main vessel and vessel branch, a problem that he termed the “Achilles' heel” of the procedure.

The system employs what looks to be small nodes used as markers that can be imaged so as to help to guide positioning of the system and then follow-on assessment of placement. The system is employed using “positioning rules” concerning placement, where the stents are expanded and where the markers are to be placed, Rogers noted.

He reported that preclinical work has been launched, with an FDA pivotal trial slated to begin in 2009.

Thomas Ischinger, MD, of Klinkum Bogenhausen (Munich, Germany) described the SideKick SDS and VascuTrak PTA catheters, noting the high frequency of “side branch involvement” in up to 30% of all cases requiring percutaneous coronary intervention.

The primary strategy of this system is to focus on access of the main vessel with the primary part of the device. After access of the primary vessel, a guidewire from the side of the device then can be steered at various angles into the vessel branch for deployment of stenting there.

Ischinger's imaging illustrations demonstrated the ease, flexibility and steerability of the system, necessary for the problem of assessing side branch vessels at various angles and dealing with the varied occurrence of plaque in both the main and branching vessels.

Carlos Gonzalez Resendiz, of developmental firm Design and Performance , noted the challenge of dealing with “lots of turbulence” in the areas of bifurcated vessels and the problems for stent positioning and placement.

The result of previous attempts to stent these areas had proved to be “a mess,” he said, using a slide showing what looked very much like a plate of spaghetti to illustrate.

Hedescribed the company's BC stent as an “over- and under-covered” device able to deal with the different angles of the branch vessel as a solution to this turbulence anda “new concept” dealing with the problem of side branch restenosis.

The device is quite early stage, with Resendiz noting that Design and Performance has not started animal research.

Addressing the issue of catheter steerability was Rafael Beyer, of Corindus (Auburndale, Massachusetts), describing the company's remote-controlled system for doing this often difficult and muscle-intensive task.

Corindus has developed the CorPath system for controlling devices from beside the bedside, or in the next room, or in some other remote location. Significantly, this can be outside the zone of radiation used in interventional procedures.

The system consists of a bedside unit and a control console. It utilizes physician fluoroscopic control similar to routine practice to allow, the company said, “maneuvering and torquing” of cath lab devices and can be integrated into exiting cath lab systems.

Beyer emphasized the growing number of interventional procedures, which come with a variety of exposure problems and significant physical stresses on those using traditional guidance technologies.

He discussed the initial trials of the system, which have demonstrated safety and efficacy, and said the company is projecting that an FDA clinical trial, CORRECT (Coronary Remote Control Catheterization Trial) trial, will begin in the third quarter of this year at several U.S. centers.