Surgical stapler with reduced clamp gap for insertion

[0001] The invention generally relates to surgical staplers and stapling.

[0002] An endocutter is a surgical tool that staples and cuts tissue to transect that tissue while leaving the cut ends hemostatic. An endocutter is small enough in diameter for use in minimally invasive surgery, where access to a surgical site is obtained through a trocar, port, or small incision in the body. A linear cutter is a larger version of an endocutter, and is used to transect portions of the gastrointestinal tract. A typical endocutter receives at its distal end a disposable single-use cartridge with several rows of staples, and includes an anvil opposed to the cartridge. The surgeon inserts the endocutter through a trocar or other port or incision in the body, orients the end of the endocutter around the tissue to be transected, and compresses the anvil and cartridge together to clamp the tissue. Then, a row or rows of staples are deployed on either side of the transection line, and a blade is advanced along the transection line to divide the tissue. Traditionally, it has been important to maintain a substantially constant gap between the anvil and the cartridge for proper staple formation. A staple urged outward from the cartridge or other staple holder is designed to encounter a staple pocket or other feature in the anvil at a certain point in its travel. If the staple encounters that staple pocket or other feature in the anvil too soon or too late, the staple may be malformed. For example, if the gap is too large, the staple may not be completely formed. As another example, if the gap is too small, the staple may be crushed.

[0006] The use of the same reference symbols in different figures indicates similar or identical items.

[0007] U.S. Patent Application Publication No. 2009/0065552, published on Mar. 12, 2009 (the “Endocutter Document”), is hereby incorporated by reference herein in its entirety.

[0008] Referring to FIG. 1, an end effector 2 may include a staple holder 4 movable relative to an anvil 6. The staple holder 4 and anvil 6 may be configured substantially as set forth in the Endocutter Document, as modified by the contents of this document. The proximal end of the end effector 2 may be slidably held within an overtube 8. The proximal end of the end effector 2 may extend into the distal end of the overtube 8. The staple holder 4 may include at least one generally vertically-oriented slot 10 defined therein, as viewed from the side. Advantageously, one slot 10 is defined in each side of the staple holder 4, in proximity to the proximal end of the staple holder 4. Alternately, a different number of slots 10 is provided, and/or the location of at least one slot 10 is different. Alternately, at least one slot 10 may be oriented other than generally vertically. An axle 12 extends outward from the anvil 6 into each slot 10. Each axle 12 is slidable within the corresponding slot 10.

[0009] Initially, the end effector 2 may be in a first configuration for insertion through a trocar port or other opening in a patient, where substantially no gap exists between the anvil 6 and the staple holder 4. This distance between the anvil 6 and the staple holder 4 optionally may be referred to as a “zero gap.” In the first, insertion configuration, each axle 12 may be located at or near the bottom of the corresponding slot 10, in order to minimize the gap between the anvil 6 and the staple holder 4. When the end effector 2 is in the first, insertion configuration, the outer dimensions of the end effector 2 may be equal to or less than the outer dimensions of the overtube 8. That is, the outer dimensions of the end effector 2 may fit within the perimeter of the distal end of the overtube 8 as viewed on end. In this way, the cross-sectional area of the end effector 2 is minimized. Alternately, the end effector 2 may be sized or shaped differently in the first, insertion configuration. At least part of the overtube 8 may be inserted into the patient along with the end effector 2.

[0010] Referring also to FIG. 2, after insertion into the patient, the end effector 2 may be opened to a second, unclamped configuration in any suitable manner. As one example, the overtube 8 may be withdrawn proximally relative to the end effector 2. The anvil 6 may be pivotable upward relative to the staple holder 4, and/or the anvil 6 may be biased upward relative to the staple holder 4 such as by a leaf spring or compression spring 14. As the overtube 8 is withdrawn proximally, that spring 14 pushes the anvil 6 upward relative to the staple holder 4. The anvil 6 may be pivotally connected to the staple holder 4 such that the upward bias of the spring 14 pushes the distal end of the anvil 6 upward. (The use of terms such as “upward” in this document refers to the orientation of parts on the page, and in no way limits the orientation of the device in use.) As the anvil 6 is pushed upward, each axle 12 is also pushed upward within the corresponding slot 10. Each axle 12 may be pushed upward to the upper end of the corresponding slot 10, or to a location between the upper and lower ends of the slot 10. As another example, the anvil 6 is not biased relative to the staple holder 4, and a mechanical linkage (not shown) or other mechanism acts to push the distal end of the anvil 6 upward as the overtube 8 is withdrawn proximally relative to the end effector 2. As the anvil 6 is urged upward by the linkage or other mechanism, each axle 12 is also pushed upward within the corresponding slot 10. Each axle 12 may be pushed upward to the upper end of the corresponding slot 10, or to a location between the upper and lower ends of the slot 10. Where each axle 12 is located in the upper end of the corresponding slot 10, the end effector 2 can open to its widest position.

[0011] The opened end effector 2 in the second, unclamped position is moved relative to tissue to be treated in order to place the anvil 6 on one side of that tissue and the staple holder 4 on the other side. The end effector 2 is then moved to the third, clamped position. Referring also to FIG. 3, the overtube 8 is advanced distally relative to the end effector 2. As the overtube 8 advances, the distal end of the overtube 8 encounters an angled ramp 16 of the anvil 6 on the upper surface of the anvil 6. Alternately, the ramp 16 is located on a different surface of the anvil 6, and/or more than one ramp 16 is provided. The ramp 16 is angled or curved downward proximally. As the overtube 8 contacts that ramp 16, further distal motion of that overtube 8 pushes the anvil 6 downward. Where the anvil 6 is rotationally connected to the staple holder 4, such as at the axles 12, the anvil 6 rotates such that the distal end of the anvil 6 moves closer to the staple holder 4. The anvil 6 moves downward, compressing tissue between the anvil 6 and the staple holder 4. The thickness of the tissue stops the clamping motion of the end effector 2. Where the tissue is thick, each axle 12 may be located at the upper end of the corresponding slot 10 when the end effector is in the third, clamped position of FIG. 3. Where the tissue is thinner, each axle 12 may be located in the corresponding slot 10 between the upper and lower ends thereof. That is, each axle 12 may float in the corresponding slot 10, and the position of the axle in that slot 10 is determined by the thickness of the clamped tissue. After the tissue is treated, the end effector 2 is moved back to the second, unclamped position of FIG. 1 by retracting the overtube 8 proximally relative to the end effector 2. The end effector 2 may then be moved back to the third, clamped position to treat tissue in a different location; if so, additional staples may be advanced into the staple holder 4 as set forth in the Endocutter Document. Alternately, if treatment of tissue is complete, the overtube 8 may be advanced distally relative to the end effector 2. Without tissue located between the anvil 6 and the staple holder 4, as the overtube 8 advances distally relative to the end effector 2, the distal end of the overtube 8 encounters the ramp 16 and urges the anvil 6 downward to the first, insertion configuration with substantially no gap between the anvil 6 and staple holder 4. The absence of a gap between the anvil 6 and the staple holder 4 results from the absence of tissue between the anvil 6 and staple holder 4, allowing the anvil 6 and staple holder 4 to move together to the first, insertion configuration without resistance from tissue.

[0012] While the invention has been described in detail, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention. It is to be understood that the invention is not limited to the details of construction, the arrangements of components, and/or the method set forth in the above description or illustrated in the drawings. Statements in the abstract of this document, and any summary statements in this document, are merely exemplary; they are not, and cannot be interpreted as, limiting the scope of the claims. Further, the figures are merely exemplary and not limiting. Topical headings and subheadings are for the convenience of the reader only. They should not and cannot be construed to have any substantive significance, meaning or interpretation, and should not and cannot be deemed to indicate that all of the information relating to any particular topic is to be found under or limited to any particular heading or subheading. Therefore, the invention is not to be restricted or limited except in accordance with the following claims and their legal equivalents.