Shturman Cardiology Systems, Inc.

Andrei Nevzorov

Leonid Shturman

Mikhail Spassky

A method of manufacturing a rotational atherectomy drive shaft having an asymmetrical tissue removal section. One or more strands of wire are helically wound about an elongated mandrel having an enlarged diameter section with a predetermined shape, thereby forming an elongated, flexible drive shaft which has an enlarged diameter tissue removal section. A portion of the drive shaft, including the enlarged diameter tissue removal section, is placed into a first clamp and given a first heat treatment to give the wire turns of the enlarged diameter tissue removal section an initial set, thereby preserving the initial shape of the enlarged diameter tissue removal section of the drive shaft. The drive shaft is then removed from the first clamp and the mandrel is dissolved. The enlarged diameter section of the drive shaft is then deformed to an asymmetrical shape by placing a portion of the drive shaft, including the enlarged diameter tissue removal section, into a second clamp. The clamped portion of the drive shaft is then heat treated for a second time to give wire turns of the enlarged diameter tissue removal section a new set, thereby preserving the asymmetrical shape of the enlarged diameter section. In its asymmetrical shape the enlarged diameter tissue removal section has a longitudinally flat &ldquo;side&rdquo;&mdash;i.e., all wire turns of the tissue removal section may be connected by an imaginary straight line which throughout its length is parallel to the rotational axis of the drive shaft.

Eccentric drive shaft for atherectomy device and method for manufacture

A rotational atherectomy device having a flexible, elongated, rotatable drive shaft with an eccentric enlarged diameter section. At least part of the eccentric enlarged diameter section has a tissue removing surface. The eccentric enlarged diameter section of the drive shaft has a center of mass and/or geometric center spaced radially from the rotational axis of the drive shaft, facilitating the ability of the device to open the stenotic lesion to a diameter substantially larger than the outer diameter of the enlarged diameter section.

Eccentric rotational atherectomy device

An atherectomy device for removing tissue from an artery. The device includes a flexible, elongated drive shaft rotatable about a guide wire, the drive shaft having an enlarged diameter tissue removal section. The drive shaft and the enlarged diameter tissue removal section are comprised of helically wound wire. Wire turns of the proximal portion of the tissue removal section have diameters that gradually increase distally at a generally constant rate thereby forming generally the shape of a cone. Wire turns of the distal portion of the enlarged diameter tissue removal section have diameters that gradually decrease distally thereby forming a generally convex distal portion. At least part of the tissue removal section includes an external coating of an abrasive material to define an abrasive segment of the drive shaft. The drive shaft may include a reduced diameter segment located near the enlarged diameter tissue removal section to facilitate smooth rotation of the drive shaft and its tissue removal section about the guide wire when the atherectomy device is rotated at high speeds. Preferably such a reduced diameter segment is provided just proximal to the enlarged diameter tissue removal section, and preferably the entire portion of the drive shaft distal to the enlarged diameter tissue removal section also has a similarly reduced diameter. The maximum outer diameter and length of the abrasive segment may be selected so that, at operational rotational speeds and under load, at least some of the wire turns of the proximal portion of the enlarged diameter tissue removal section unwind from their at-rest diameter to an effective outer diameter which is the same as or larger than the maximum outer diameter of the abrasive segment.

Rotational atherectomy device

A method of forming an elongate, flexible drive shaft which has utility as a rotational atherectomy device. In accordance with this method, an inner helical coil having a lumen and a proximal end is formed by winding a plurality of wires about a forming mandrel. An outer helical coil having a lumen and a proximal end is formed by winding a single wire with a mandrel-less coil forming machine. The inner helical coil is positioned within the outer helical coil to define a drive shaft. The inner and outer helical coils are oriented such that the inner helical coil is wound in a direction opposite that in which the outer helical coil is wound.

A method of manufacturing a rotational atherectomy drive shaft having an asymmetrical tissue removal section. One or more strands of wire are helically wound about an elongated mandrel having an enlarged diameter section with a predetermined shape, thereby forming an elongated, flexible drive shaft which has an enlarged diameter tissue removal section. A portion of the drive shaft, including the enlarged diameter tissue removal section, is placed into a first clamp and given a first heat treatment to give the wire turns of the enlarged diameter tissue removal section an initial set, thereby preserving the initial shape of the enlarged diameter tissue removal section of the drive shaft. The drive shaft is then removed from the first clamp and the mandrel is dissolved. The enlarged diameter section of the drive shaft is then deformed to an asymmetrical shape by placing a portion of the drive shaft, including the enlarged diameter tissue removal section, into a second clamp. The clamped portion of the drive shaft is then heat treated for a second time to give wire turns of the enlarged diameter tissue removal section a new set, thereby preserving the asymmetrical shape of the enlarged diameter section. In its asymmetrical shape the enlarged diameter tissue removal section has a longitudinally flat 'side'--i.e., all wire turns of the tissue removal section may be connected by an imaginary straight line which throughout its length is parallel to the rotational axis of the drive shaft.

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Moscow, Russia

Andrei Nevzorov