BACKGROUND

1. Technical Field

This disclosure is directed to a surgical stapling device and, more particularly, to a linear surgical stapling device having a tool assembly that defines a tissue gap and includes a locking member to maintain the tissue gap during firing of the stapling device.

2. Background of Related Art

Surgical stapling devices are commonly used during a variety of surgical procedures to staple and/or cut tissue. Stapling and cutting of tissue can be accomplished more quickly using surgical stapling devices than can be accomplished using traditional suturing techniques. In addition, endoscopic stapling devices can be used to perform less invasive surgical procedures than possible using traditional suturing techniques. As such, the use of surgical stapling devices to perform certain surgical procedures to reduce patient trauma and improve patient recovery times is desirable.

Typically, linear endoscopic surgical stapling devices include a tool assembly that includes a staple cartridge and an anvil assembly that are movable in relation to each other between open and clamped positions. The staple cartridge defines a plurality of staple pockets that receive staples and the anvil assembly defines a plurality of staple deforming pockets. When the tool assembly is in the clamped position, the staple deforming pockets of the anvil assembly are aligned with the staple pockets of the staple cartridge such that legs of the staples are received and deformed within the staple deforming pockets when the stapling device is fired. The staple cartridge and the anvil assembly must be properly aligned to effect proper staple formation.

Generally, the staple cartridge and the anvil assembly have proximal ends that are secured to each other by a pivot member such that the staple cartridge and the anvil assembly can be pivoted from the open position in which distal ends of the staple cartridge and the anvil assembly are spaced from each other to the clamped position in which the staple cartridge and the anvil assembly are in juxtaposed alignment. During firing of the staples from the staple cartridge, forces on the staple cartridge and the anvil assembly for firing the staples tend to deflect the staple cartridge and anvil assembly outwardly away from each other. In certain stapling devices, a knife bar is provided that includes upper and lower beams that engage the anvil assembly and staple cartridge to minimize deflection of the anvil and cartridge assemblies during firing.

SUMMARY

One aspect of this disclosure is directed to a tool assembly including an anvil, a cartridge assembly, a sled, and a locking member. The anvil and the cartridge assembly each have a proximal portion and a distal portion. The proximal portion of the cartridge assembly is pivotally coupled to the proximal portion of the anvil. The distal portion of the anvil defines a bore therein. The sled is slidably received in the cartridge assembly and configured to move from a proximal position to a distal position to advance staples from the cartridge assembly. The locking member is rotatably supported on the distal portion of the cartridge assembly and positioned for receipt in the bore. The locking member is operably coupled to the sled, such that advancement of the sled from the proximal position toward the distal position rotates the locking member relative to the bore to approximate the distal portions of the anvil and cartridge assembly.

In aspects, the locking member may have an extension having a threaded outer surface. The bore in the distal portion of the anvil may be defined by a threaded inner surface configured to threadedly engage the threaded outer surface of the extension of the locking member.

In aspects, the anvil and cartridge assembly may be movable between an expanded position, in which the extension of the locking member is spaced from the bore in the anvil, and a first approximated position, in which the threaded outer surface of the extension of the locking member is engaged with the threaded inner surface of the anvil.

In aspects, the anvil and cartridge assembly may be configured to move from the first approximated position to a second approximated position in response to rotation of the locking member while the threaded outer surface of the locking member is engaged with the threaded inner surface of the anvil.

In aspects, the tool assembly may further include a tether having a proximal end portion coupled to the sled, and a distal end portion disposed about the locking member, such that translation of the sled rotates the locking member via the tether.

In aspects, the locking member may have a barrel portion rotatably supported in the cartridge assembly. The distal end portion of the tether may be fixed about the barrel portion.

In aspects, the tool assembly may further include a biasing member received in the barrel portion and coupled to the cartridge assembly. The biasing member may be configured to urge the tether in a distal direction.

In aspects, the locking member may be spring-biased to urge the tether in a distal direction.

In aspects, the tether may be a looped band defining a plurality of apertures. The locking member may have a plurality of circumferentially spaced protuberances configured for receipt in the corresponding plurality of apertures.

In aspects, the sled may have a pin extending therefrom and received in an aperture of the plurality of apertures, such that translation of the sled moves the band along a looped path.

In aspects, the distal portion of the anvil may have a tissue dissector, and the tissue dissector may define the bore.

In accordance with another aspect of the disclosure, a surgical stapling device is provided and includes a handle assembly, an elongated body extending distally from the handle assembly, a drive shaft, and a tool assembly. The handle assembly includes a trigger, and the drive shaft has a proximal end portion operably coupled to the trigger. The tool assembly is coupled to a distal portion of the elongate body and includes an anvil, a cartridge assembly, a tether, and a locking member. The anvil and cartridge assembly each has a proximal portion and a distal portion. The proximal portion of the cartridge assembly is pivotally coupled to the proximal portion of the anvil between an expanded position and an approximated position. The distal portion of the anvil defines a bore therein. The tether has a proximal end portion coupled to a distal end portion of the drive shaft. The locking member is rotatably supported on the distal portion of the cartridge assembly and positioned for receipt in the bore. The tether has a distal end portion disposed about and coupled to the locking member, such that when the cartridge assembly and anvil are in the approximated position, advancement of the drive shaft rotates the locking member relative to and within the bore to approximate the distal portions of the anvil and cartridge assembly.

In aspects, the locking member may have an extension having a threaded outer surface. The bore in the distal portion of the anvil may be defined by a threaded inner surface configured to threadedly engage the threaded outer surface of the extension of the locking member when the anvil and cartridge assembly are in the approximated position.

In aspects, in the expanded position, the extension of the locking member may be spaced from the bore in the anvil, and in the approximated position, the threaded outer surface of the extension of the locking member may be engaged with the threaded inner surface of the anvil.

In aspects, the locking member may have a barrel portion rotatably supported in the cartridge assembly. The barrel portion may have the distal end portion of the tether fixed thereabout.

In aspects, the tool assembly may further include a biasing member received in the barrel portion and coupled to the cartridge assembly. The biasing member may be configured to urge the tether in a distal direction.

In aspects, the locking member may be spring-biased to urge the tether in a distal direction.

In aspects, the tether may be a looped band defining a plurality of apertures. The locking member may have a plurality of circumferentially spaced protuberances configured for receipt in the corresponding plurality of apertures.

In aspects, the tool assembly may further include a sled slidably received in the cartridge assembly. The sled may interconnect the distal end portion of the drive shaft and the proximal end portion of the tether. The sled may be configured to move from a proximal position to a distal position to advance staples from the cartridge assembly in response to an actuation of the trigger.

In aspects, the locking member may be configured to rotate in response to movement of the sled between the proximal and distal positions.

