Scimed Life Systems, Inc.

Thomas J Hiblar

Robert Lawrence Barry

Verivada C Chandrasekaran

Lixiao Wang

John Jianhua Chen

Edward I Wulfman

Sheng-Ping Zhong

Zihong Guo

Mark H Wyzgala

Irina Nazarova

Thomas D Kadavy

Eric B Hamilton

Kurt M Laundroche

Nancy Haig

Eric W Baker

Roy T Strandberg

A rotational ablation atherectomy device including a flexible drive shaft and a compressible burr that may be inserted and extracted from a patient using a catheter having a diameter that is smaller than the operational diameter of the burr. In one embodiment, the burr includes a nose portion coupled to the drive shaft and one or more flexible abrasive disks disposed rearwardly from the nose portion. The flexible disks are foldable to be slidably received within a catheter. In another embodiment, the burr includes a support member coupled to the drive shaft, the support member having a resilient panel that spirals outwardly, forming a generally cylindrical ablation surface. The flexible panel can be elastically urged toward the support member and slidably inserted into the catheter. In a third embodiment, the burr includes a plurality of struts that are coupled to the drive shaft. An elastically compressible body disposed between the struts permits the struts to flex inwardly to reduce the burr diameter. In another embodiment, the burr includes a plurality of flexible wires attached at proximal and distal ends to the drive shaft. An abrasive sheath is disposed over the wires. The wires can be bent inwardly to compress the burr and re-expanded by rotation of the burr. In another embodiment, the burr comprises a nose portion and a resilient shell having a compressible, larger diameter abrasive section disposed at the proximal end of the nose portion.

Compressible atherectomy burr

An atherectomy burr has an operating diameter that is larger than the diameter of a catheter in which the burr is routed. The burr may include a polymeric balloon that is coated with an abrasive and that expands when the burr is rotated. When the burr is rotated, the polymeric tube expands by centrifugal force. The maximum expansion of the burr is controlled by an expansion mechanism. Various mechanisms are disclosed for controlling the maximum diameter of the burr thus preventing the burr from over expanding. In addition, the present invention includes a system for preventing the loose ablated particulate from reembolizing in the distal vasculature. The system includes an ablation burr that has abrasive disposed on the proximal end that is pulled back toward the guide catheter to ablate the lesion. The burr creates a seal when expanded to block the ablated particulate so that the aspiration system can remove the particulate from the patient vessel or stent. Alternatively, the burr system may include a self expanding seal that is deployed out of the aspiration sheath so that a slight vacuum can remove the large loose particulate form, the patient's vessel or stent.

Expandable ablation burr

An ablation burr has a body provided with an inner circumferential rim and an outer circumferential rim that are concentric and spaced longitudinally by a selected distance along the length of the burr. The outer circumferential rim has a generally smooth convex outer surface that reduces damage to a vessel wall or stent. A leading surface of the burr extends between the inner and outer circumferential rims in a substantially uniform, concave manner. An abrasive, for example, diamond grit, is provided on the leading surface. The burr is selectively rotated by a drive shaft, causing the abrasive leading surface of the burr to ablate unwanted deposits. If desired, a wire extends co-axially through the body such that a distal end of the wire extends out of the distal end of the burr. An abrasive tip may be coupled to the distal end of the wire, and is selectively rotated, to ablate unwanted deposits. The burr may be made of a compressible elastomeric material, to facilitate positioning the burr through restrictive openings, such as the coronary ostia. To prevent the burr from becoming welded to a spring tip at the end of the guide wire, a bearing may be provided at a distal region of the guide wire. The bearing has a dynamic member that acts as a bumper and rotates when the ablation device is advanced to the distal region of the guide wire and contacts the dynamic member. In an alternative embodiment of the invention, the leading surface of the burr includes one or more aspiration ports through which debris that is ablated from the occlusion may be removed from a patient's vessel.

Ablation device including guidewire with abrasive tip

An atherectomy burr having an operating diameter that is larger than the diameter of a catheter in which the burr is routed. The burr may include a flexible polymeric tube that is plated with an abrasive and that expands when the burr is rotated. Metal fibers are embedded into burr to improve strength and to control the maximum expansion diameter of the burr. The abrasive is plated on the burr by first selectively exposing the underlying metal. The exposed metal is then plated with a layer of metal such as nickel having a slurry of diamond particles disposed therein using an electro and/or electroless plating method. When the burr is rotated, the polymeric tube expands by centrifugal force to ablate a new lumen in the patient's vessel.

Expandable atherectomy burr with metal reinforcement

An expandable atherectomy burr has numerous cutting elements that expand radially outward as the burr is rotated. The cutting elements can include arms or flaps that have an abrasive surface thereon and expand as the burr is rotated. In an alternative embodiment, the burr includes a stack of cutting disks, each of which includes cutting elements that expand as the burr is rotated in order to create variably sized lumens in a vessel.

Expandable atherectomy burr

A guide wire brake for use in an ablation assembly includes a clamp positioned in and between recesses provided in an air-actuated piston and a retainer. The clamp is provided with a first member and a second member coupled together on opposite sides of a spring member. An outer surface of the clamp is tapered to matingly engage the tapered inner surface of the first and second recesses. In operation, the piston is in fluid communication with a source of air. As air contacts an inner surface of the piston, the piston moves toward the retainer, thereby pushing the first and second recesses together along the tapered outer surface of the clamp. This action causes the first and second members to overcome the spring force of the spring member, and clamp together against a guide wire extending therethrough, thereby preventing longitudinal and rotational motion of the guide wire. The first member has two studs that extend through apertures provided in the second member, and a crescent washer is provided around each of the studs, to function as a spring.

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Everett, WA, United States of America

Thomas J Hiblar