Patent Description:
Anastomosis is the surgical joining of separate hollow organ sections. Typically, an anastomosis procedure follows surgery in which a diseased or defective section of hollow tissue is removed, and the end sections are stapled via a surgical stapler. Depending on the desired anastomosis procedure, the end sections may be joined by circular or side-to-side organ reconstruction methods, for instance.

In a circular anastomosis procedure, the two ends of the organ sections are joined by means of a stapling instrument which drives a circular array of staples through the end section of each organ section and simultaneously cores any tissue interior of the driven circular array of staples to free the tubular passage. Typically, these instruments include an elongated body portion having a handle portion at a proximal end to actuate the instrument and a staple holding component disposed at a distal end. An anvil assembly including an anvil retention rod with an attached anvil head is mounted to a trocar assembly at the distal end of the instrument adjacent the staple-holding component. Opposed end portions of tissue of the hollow organ(s) to be stapled are clamped between the anvil head and the staple holding component. The clamped tissue is stapled by driving one or more staples from the staple holding component so that the ends of the staples pass through the tissue and are deformed by the anvil head. An annular knife is advanced to core tissue within the hollow organ to free a tubular passage within the organ.

Besides anastomosis of hollow organs, surgical stapling instruments for performing circular anastomosis have been used to treat internal hemorrhoids in the rectum. Typically, during use of a circular stapling device for hemorrhoid treatment, the anvil head and the staple holding-component of the surgical stapling instrument are inserted through the anus and into the rectum with the anvil head and the staple-holding component in an open or unapproximated position. Thereafter, a pursestring suture is used to pull the internal hemorrhoidal tissue towards the anvil rod. Next, the anvil head and staple-holding component are approximated to clamp the hemorrhoidal tissue between the anvil head and the staple holding component. During the approximation of the anvil head and the staple-holding component, the trocar assembly engages the anvil retention rod. The surgical stapling instrument is fired to remove the hemorrhoidal tissue and staple the cut tissue.

<CIT> discloses an adapter assembly including a sleeve, a trocar assembly releasably securable within the sleeve, and a retaining mechanism configured to releasably secure the trocar assembly within the sleeve. The retaining mechanism includes a retaining block, a cam wire moveably positioned relative to the retaining block between a lock position and a release position, a retaining block extension for maintaining the cam wire relative to the retaining block, a button member in operable engagement with the cam wire, and a pair of retaining members. The button member includes a center beam moveable from an unflexed position in engagement with a stop tab of the retaining block extension to prevent movement of the button member to a flexed position out of alignment with the stop tab to permit movement of the button member.

The present invention is defined by the features of independent claims <NUM> and <NUM>. Further embodiments are provided by the dependent claims.

In aspects of the present disclosure, the support member includes first and second portions that are attachable to each other.

In another aspect of the present disclosure, the distal position of the support member relative to the elongate shaft allows movement of the pin between the inserted position and a retracted position.

In a further aspect of the present disclosure, the proximal position of the support member maintains the pin in the inserted position.

In yet another of the present disclosure, the support member further includes first and second pads that are configured to support first and second drive members to limit radial movement of the first and second drive members during an actuation sequence.

In another aspect of the present disclosure, a seal is positioned at a distal end of the support member. The seal is threadably coupled to the elongate shaft to maintain the support member in the proximal position.

In one aspect of the present disclosure, the ramp includes a tapered leading edge adapted to cammingly engage the head of the pin.

In aspects of the present disclosure, the trocar assembly is longitudinally repositionable relative to the elongate shaft with the pin in the retracted position.

According to another aspect of the present disclosure, an end effector for use with a surgical instrument includes an elongate shaft having a lumen. An adapter is disposed at a proximal end of the elongate shaft. The adapter is configured for coupling the elongate shaft with a handle assembly of the surgical instrument. A support member has proximal and distal openings defining a passage therethrough. The support member is disposed in the lumen of the elongate shaft and slidable relative to the elongate shaft between a proximal position and a distal position. A trocar assembly is insertable into the passage of the support member. The trocar assembly has a trocar member extending from a sleeve. The sleeve includes an orifice extending through a wall of the sleeve. A pin is disposed in the elongate shaft and is slidable in a direction transverse to a longitudinal axis of the elongate shaft. The pin is insertable into the orifice of the sleeve for retaining the trocar assembly longitudinally stationary relative to the elongate shaft and defining an inserted position of the pin. A ramp has a tapered edge and is located in a proximal region of the support member. The ramp is engageable with a head of the pin to maintain the pin in the orifice of the sleeve.

In one aspect of the present disclosure, the proximal position of the support member maintains the pin in the inserted position.

In a further aspect of the present disclosure, the support member further includes first and second pads that are configured to support first and second drive members to limit radial movement of the first and second drive members during an actuation sequence.

In yet another aspect of the present disclosure, a seal is positioned at a distal end of the support member. The seal being threadably coupled to the elongate shaft to maintain the support member in the proximal position.

In aspects of the present disclosure, the tapered edge is adapted to cammingly engage the head of the pin.

In an aspect of the present disclosure, sliding the support member includes the support member having first and second portions that are attachable to each other.

In a further aspect of the present disclosure, sliding the support member includes the support member having first and second pads that are configured to support first and second drive members to limit radial movement of the first and second drive members during an actuation sequence.

In yet another aspect of the present disclosure, engaging the head of the pin includes engaging the head of the pin with a tapered edge of the ramp.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate aspects and features of the disclosure and, together with the detailed description below, serve to further explain the disclosure, in which:.

Aspects of the disclosure are described hereinbelow with reference to the accompanying drawings; however, it is to be understood that the disclosed aspects are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure.

Descriptions of technical features of an aspect of the disclosure should typically be considered as available and applicable to other similar features of another aspect of the disclosure. Accordingly, technical features described herein according to one aspect of the disclosure may be applicable to other aspects of the disclosure, and thus duplicative descriptions may be omitted herein. Like reference numerals may refer to like elements throughout the specification and drawings.

Initially, with reference to <FIG> and <FIG>, a surgical stapler is shown and referenced generally as surgical stapler <NUM>. The surgical stapler <NUM> is a circular stapler and includes a handle <NUM> assembly at one end and an elongate tubular shaft <NUM> extending from the handle assembly <NUM>. The tubular shaft <NUM> includes an open distal end <NUM> for receiving a trocar assembly <NUM> therethrough such that the trocar assembly <NUM> is received in a lumen <NUM> (<FIG>) of the tubular shaft <NUM>. Although illustrated as a powered surgical stapler, the surgical stapler <NUM> may be a manually operated instrument such as that shown in commonly owned <CIT>. The handle assembly <NUM> includes a power source (not shown) and buttons for operating the surgical stapler <NUM>. A distal end of the tubular shaft <NUM> is adapted for coupling with a staple cartridge. A proximal end of the tubular shaft <NUM> includes an adapter configured for coupling the tubular shaft <NUM> with the handle assembly <NUM>. The handle assembly <NUM> includes a fixed handle <NUM>, an actuation button <NUM>, and an approximation mechanism <NUM> for moving the trocar assembly <NUM> axially with respect to the tubular shaft <NUM>. The structure and function of handle assembly <NUM> will only be described herein to the extent necessary. Commonly owned <CIT> discloses a surgical device having a powered actuator assembly including first and second drive members. In addition, it is envisioned that the independent actuation strokes may be completed by the same drive member completing two strokes or by two separate drive members. A support member <NUM> (<FIG>), as will be described in further detail hereinbelow, is positioned in the tubular shaft <NUM>. The trocar assembly <NUM> includes a trocar member <NUM> extending from a sleeve <NUM>.

With continued reference to <FIG>, a distal portion of the tubular shaft <NUM> is shown with an outer wall of the tubular shaft <NUM> removed and illustrates the location of the support member <NUM> (<FIG>) relative to the tubular shaft <NUM>. The support member <NUM> includes a first portion 100a and a second portion 100b. As shown, a proximal end <NUM> of the trocar assembly <NUM> is insertable through the open distal end <NUM> of the tubular shaft <NUM>. With the outer wall removed, a staple band <NUM> and a knife band <NUM> are visible. The staple band <NUM> is operatively coupled with a staple actuator (not shown) and the knife band <NUM> is operatively coupled with a knife member (not shown). During a firing sequence, actuation (i.e., axial displacement) of the staple band <NUM> causes concomitant axial displacement of the staple actuator (not shown) thereby firing staples from the surgical stapler <NUM>. Axial displacement of the knife band <NUM> causes concomitant axial displacement of a knife member (not show) for severing tissue. An example of a surgical stapling instrument with a staple band and a knife band is disclosed in commonly owned <CIT>.

Referring now to <FIG>, a more detailed explanation of the support member <NUM> follows. Initially, the support member <NUM> is formed from the first portion 100a and the second portion 100b. The support member <NUM> may also be a single, unitary structure. The first and second portions 100a, 100b of the support member <NUM> are mirror images of each other. Each of the first and second portions 100a, 100b has a tab <NUM> and a recess <NUM> located in a distal region thereof. The tabs <NUM> and the recesses <NUM> are oriented <NUM>° apart such that the tab <NUM> of the first portion 100a is receivable in the recess <NUM> of the second portion 100b and the tab <NUM> of the second portion 100b is receivable in the recess <NUM> of the first portion 100a. The engagement between the tabs <NUM> and the recesses <NUM> is a friction fit that helps hold the first and second portions 100a, 100b together and also aligns the first portion 100a relative to the second portion 100b. Further, each of the first and second portions 100a, 100b of the support member <NUM> includes projections <NUM> that extend radially inward from an inner surface of the respective first and second portions 100a, 100b. Each projection <NUM> is a planar structure for separating and supporting the knife band <NUM> from the staple band <NUM>. The projections <NUM> also limit radial deflection of the knife band <NUM> and the staple band <NUM> during actuation of the knife band <NUM> and the staple band <NUM> as will be discussed in detail hereinbelow. Additionally, proximal regions of the first and second portions 100a, 100b are configured to engage pins <NUM> (<FIG>) that are slidably coupled to the tubular shaft <NUM> as will be discussed in detail hereinbelow. When the first and second portions 100a, 100b are coupled together, the support member <NUM> has an open proximal end <NUM> and an open distal end <NUM> that define a passage <NUM> through the support member <NUM>. The passage <NUM> is configured to receive the trocar assembly <NUM> therethrough (<FIG>).

Turning now to <FIG>, the first and second portions 100a, 100b are attached to one another forming the support member <NUM>. Regardless of whether the support member <NUM> is formed from the first and second portions 100a, 100b or is a unitary structure, the support member <NUM> is positioned circumferentially within the tubular shaft <NUM> such that the support member <NUM> and the tubular shaft <NUM> are coaxial. The support member <NUM> is slidable along a longitudinal axis of the tubular shaft <NUM> between a distal or first position (<FIG>) and a proximal or second position (<FIG>). The first position is distal relative to the second position. While the support member <NUM> is axially repositionable along the tubular shaft <NUM>, the engagement between the projections <NUM> of the first and second portions 100a, 100b with the knife band <NUM> and the staple band <NUM> maintain the support member <NUM> rotationally stationary with respect to the tubular shaft <NUM>. As shown in <FIG>, proximal portions of the first and second portions 100a, 100b of the support member <NUM> have ramps or tapered cam surfaces <NUM> positioned at a trailing end of the support member <NUM>. The tapered cam surfaces <NUM> engage heads <NUM> of the pins <NUM> that are located in the tubular shaft <NUM>. During proximal motion of the support member <NUM>, the engagement between the cam surfaces <NUM> and the heads <NUM> of the pins <NUM> urges the pins <NUM> to travel in receptacles <NUM> of the tubular shaft <NUM> in a direction that is orthogonal to the longitudinal axis of the tubular shaft <NUM>. Each pin <NUM> has a shank <NUM> extending from its head <NUM> that moves within its respective receptacle <NUM> and is receivable in an orifice <NUM> of the sleeve <NUM> of the trocar assembly <NUM> as will be discussed in detail below. With the support member <NUM> in the first position, the pins <NUM> are freely slidable in their receptacles <NUM>. Once the support member <NUM> is slid into the second position, as indicated by arrows A in <FIG>, the cam surfaces <NUM> of the support member <NUM> urge the pins <NUM> toward a centerline of the tubular shaft <NUM> (<FIG>). In the second position, the cam surfaces <NUM> of the support member <NUM> maintain contact with the heads <NUM> of the pins <NUM> thereby retaining the pins <NUM> stationary within their receptacles <NUM>. This arrangement maintains the axial and radial position of the trocar assembly <NUM> with respect to the tubular shaft <NUM>.

Referring now to <FIG>, the trocar assembly <NUM> is inserted through the open distal end <NUM> of the tubular shaft <NUM> and into the lumen <NUM> of the tubular shaft <NUM>. With the trocar assembly <NUM> positioned in the lumen <NUM> of the tubular shaft <NUM>, the support member <NUM> is slid proximally thereby camming the pins <NUM> as discussed previously with respect to <FIG>. Proximal movement of the support member <NUM> relative to the tubular shaft <NUM>, as indicated by arrows A, is limited by the engagement of a proximal end of the support member <NUM> contacting a raised rib <NUM> on the tubular shaft <NUM>, which acts as a travel limit stop.

As seen in <FIG>, the trocar assembly <NUM> is retained in the tubular shaft <NUM> by the pins <NUM>. The trocar assembly <NUM> is positioned coaxially within the lumen <NUM> of the tubular shaft <NUM> and slid distally into the lumen <NUM> until it is fully seated. The trocar assembly <NUM> is fully seated and rotated such that the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM> are aligned with the receptacles <NUM> of the tubular shaft <NUM>. Once the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM> are aligned with the receptacles <NUM> of the tubular shaft <NUM>, the support member <NUM> is slid proximally thereby camming the pins <NUM> towards the centerline of the tubular shaft <NUM>, as indicated by arrows B, such that distal portions of the shanks <NUM> of the pins <NUM> are received in the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM>. This arrangement fixes the orientation and position of the trocar assembly <NUM> within the tubular shaft <NUM>. A seal <NUM> is positioned at a distal end of the support member <NUM> for retaining the support member <NUM> in the second position that maintains the pins <NUM> inserted into the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM>. With additional reference to <FIG>, the seal <NUM> has threading <NUM> on its distal end for engaging corresponding threads on an inner wall of the tubular shaft <NUM>. This threaded arrangement maintains an axial position of the seal <NUM> once it is threadably coupled to the tubular shaft <NUM>. The seal <NUM> has a central opening <NUM> with a diameter greater than an outer diameter of the trocar assembly <NUM>. Additionally, the seal <NUM> has two distally extending tabs <NUM> that are diametrically opposed to one another. The tabs <NUM> are configured to engage a distal end of the support member <NUM> and retain the support member <NUM> in the second position.

Referring now to <FIG>, the seal <NUM> is coupled to the support member <NUM>. Specifically, the seal <NUM> is coupled to the distal end of the support member <NUM> such that the tabs <NUM> of the seal <NUM> are seated in notches <NUM> of the support member <NUM>. As such, the seal <NUM> and the support member <NUM> are rotationally fixed with one another.

As seen in <FIG>, the support member <NUM> is positioned within the lumen <NUM> of the tubular shaft <NUM> in its second (i.e., proximal) position. In the second position of the support member <NUM>, the cam surfaces <NUM> of the support member <NUM> are in contact with the heads <NUM> of the pins <NUM>. Contact between the cam surfaces <NUM> and the heads <NUM> of the pins <NUM> retains the pins <NUM> in an inserted position where distal ends of the shanks <NUM> of the pins <NUM> are located in the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM>. Locating the distal ends of the shanks <NUM> in the orifices <NUM> of the sleeve <NUM> of the trocar assembly <NUM> fixes the axial and radial position of the trocar assembly <NUM> with respect to the tubular shaft <NUM>. An outer surface of the support member <NUM> is in contact with an inner wall of the tubular shaft <NUM> (i.e., an interference fit) which inhibits the pins <NUM> from sliding away from the centerline of the tubular shaft <NUM> (i.e., outboard) and maintaining them in the inserted position. Additionally, the projections <NUM> of the support member <NUM> are sandwiched between the knife band <NUM> and the staple band <NUM>. Specifically, the knife band <NUM> is positioned between the projections <NUM> and a housing <NUM> while the staple band <NUM> is positioned between the projections <NUM> and an inner wall of the support member <NUM>. This provides additionally support for the knife band <NUM> and the staple band <NUM> thereby minimizing any radial deflection by either the knife band <NUM> or the staple band <NUM> during an actuations sequence.

Claim 1:
An end effector comprising:
an elongate shaft (<NUM>) having a lumen (<NUM>);
an adapter disposed at a proximal end of the elongate shaft and configured to couple the elongate shaft with a handle assembly (<NUM>) of a surgical instrument (<NUM>);
a support member (<NUM>) having proximal and distal openings defining a passage (<NUM>) therethrough, the support member disposed in the lumen of the elongate shaft and being slidable relative to the elongate shaft between a proximal position and a distal position;
a trocar assembly (<NUM>) having a sleeve (<NUM>) and a trocar member (<NUM>) disposed therein, the trocar assembly insertable into the passage of the support member and the sleeve including an orifice (<NUM>) extending through a wall thereof;
a pin (<NUM>) disposed in the elongate shaft, the pin slidable in a direction transverse to a longitudinal axis of the elongate shaft, the pin insertable into the orifice of the sleeve for retaining the trocar assembly longitudinally stationary relative to the elongate shaft and defining an inserted position of the pin; and
a ramp (<NUM>);
characterised in that
the support member is disposed in the lumen of the elongate shaft; and
the ramp is located in a proximal region of the support member, the ramp engageable with a head (<NUM>) of the pin to maintain the pin in the orifice of the sleeve.