Side-Branch Stent Treats Bifurcation Lesions

A new side-branch coronary stent provides coverage to bifurcated vessels while eliminating the need for provisional stenting, offering a new standard of care for the treatment of left main coronary artery disease.

The Tryton Side-Branch Stent is a slotted tube, balloon-expandable cobalt-chromium bare-metal stent with three zones: a "distal side-branch zone,” a "central transition zone,” and a "proximal main vessel zone.” The distal side-branch zone has the design characteristics of a standard slotted-tube workhorse (main vessel) stent. The central transition zone has a specific geometry, which contains three panels, each of which can be deformed in an independent fashion. The proximal main-vessel zone is composed of three fronds that connect proximally to the transition-zone panels and terminate in a circumferential band. The stent is provided on one of two stent delivery systems; a straight balloon-stent delivery system of standard tubular construction, which when inflated has a constant diameter of 2.5 mm; and a stepped balloon-stent delivery system that has an inflated geometry that corresponds to the three Tryton stent zones.

The Side-Branch Stent is used in conjunction with a workhorse stent deployed using standard techniques. The lesion is predilated leaving a guidewire in both the side-branch and in the main vessel. The stent is then mounted on a dedicated stent delivery system and is then positioned with the central transition zone markers straddling the side branch origin. The stent is then deployed, after which the delivery system is removed. The guidewire initially placed in the side branch is then repositioned in the distal main vessel, and a standard main vessel stent is tracked through the proximal main vessel zone of the side-branch stent into the distal main vessel. The main vessel stent is then deployed, after which the main vessel stent-delivery balloon is removed. The side branch is reaccessed and a simultaneous kissing balloon post-dilatation is performed. When the cobalt chromium bare-metal stent was used together with a standard drug eluting stent, no side branch restenosis was observed in the 30 patients treated. The Tryton Side-Branch Stent, a product of Tryton Medical (Newton, MA, USA), has received the European Community CE mark approval.

"This technology has the capacity to redefine the treatment of bifurcation lesions and resolve a frequent dilemma of the interventional cardiologist,” said Professor Patrick Serruys, M.D., head of the department of interventional cardiology at Thoraxcenter, Erasmus Medical Center (Rotterdam, the Netherlands), who led the Tryton 1 (First-In-Man) study of the new stent.


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Tryton Medical
Thoraxcenter, Erasmus Medical Center