Patent Publication Number: US-2017360441-A1

Title: Tool assembly for leak resistant tissue dissection

Description:
BACKGROUND 
     1. Technical Description 
     The present disclosure is directed to linear surgical stapling devices, and more particularly, to linear surgical stapling devices that include a tool assembly having a longitudinal proximal portion and a curved and/or angled distal portion to facilitate leak resistant dissection of body tissue. 
     2. Background of Related Art 
     The use of linear surgical stapling devices to perform total or partial removal of a body organ from a patient is known. In some procedures, e.g., gastrectomy procedures, a tool assembly of the surgical stapling device may not be long enough to cut across the entire length of the body organ. In these situations, it is necessary to perform a plurality of cutting operations with the surgical stapling device to remove the organ or a portion of the organ from the patient. 
     During each cutting operation of a surgical stapling device, tissue is divided along a cut line and staples are applied along the cut line to seal the cut. The end of the cut line defines a termination point having a vertex. Where a surgical procedure requires a plurality of cutting operations to perform the surgical procedure, the cut line includes one or more termination points. Since known surgical staplers do not apply a staple across the vertex of the termination point, the termination point is susceptible to leakage. In order to minimize the likelihood of leakage occurring, the clinician must perform the second cutting operation by intersecting the termination point in a way that the termination point is contained along the side of the organ that is being removed, i.e., the specimen side. Where multiple cutting operations are required, it can be difficult for a clinician to maintain a straight cut line while properly sealing the termination points of the cut line. 
     Accordingly, a continuing need exists in the art for a linear surgical stapling device that is configured to minimize leakage during procedures that require a plurality of cutting operations. 
     SUMMARY 
     In one aspect of the present disclosure, a tool assembly for leak resistant dissection of tissue includes a cartridge assembly and an anvil. The cartridge defines a first longitudinal axis and includes a linear longitudinal portion and transverse portion that is contiguous with and positioned distally of the longitudinal portion. The cartridge also defines a central knife slot and at least one row of staple receiving pockets positioned on each side of the knife slot. An anvil is positioned along the first longitudinal axis and has a linear longitudinal portion and a transverse portion that is contiguous with and positioned distally of the longitudinal portion. The anvil is supported adjacent to the cartridge assembly and defines an anvil knife slot that is aligned with the central knife slot of the cartridge body and at least one row of staple deforming depressions positioned on each side of the anvil knife slot. 
     The length of the longitudinal portions of the cartridge and the anvil can form at least 80 percent of the overall length of the tool assembly. 
     In embodiments, the central knife slot and the at least one row of staple receiving pockets extend along at least a portion of the transverse portion of the cartridge body. 
     In some embodiments, the anvil knife slot and the at least one row of staple deforming depressions extend along at least a portion of the transverse portion of the anvil. 
     In certain embodiments, the transverse portions of the cartridge and the anvil are curvilinear. 
     In embodiments, the transverse portions of the cartridge and anvil are curved, defining a radius of curvature. 
     In some embodiments, the transverse portions of the cartridge and anvil define a second longitudinal axis, the first longitudinal and the second longitudinal axis defining an angle β. 
     In certain embodiments, angle β is between 15 degrees and 60 degrees. 
     In embodiments, angle β is between 30 degrees and 45 degrees. 
     In some embodiments, the distal end of the central knife slot is spaced outwardly from the longitudinal axis a distance X, wherein X is between 2 mm and 10 mm. 
     In certain embodiments, X is between 4 mm and 8 mm. 
     In another aspect of the present disclosure, a surgical stapling device includes a body portion supporting a tool assembly for leak resistant dissection of tissue that includes a cartridge assembly and an anvil. The cartridge defines a first longitudinal axis and includes a linear longitudinal portion and transverse portion that is contiguous with and positioned distally of the longitudinal portion. The cartridge also defines a central knife slot and at least one row of staple receiving pockets positioned on each side of the knife slot. An anvil is positioned along the first longitudinal axis and has a linear longitudinal portion and a transverse portion that is contiguous with and positioned distally of the longitudinal portion. The anvil is supported adjacent to the cartridge assembly and defines an anvil knife slot that is aligned with the central knife slot of the cartridge body and at least one row of staple deforming depressions positioned on each side of the anvil knife slot. 
     The length of the longitudinal portions of the cartridge and the anvil can form at least 80 percent of the overall length of the tool assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the presently disclosed tool assembly for leak resistant dissection of tissue are described herein below, as part of a surgical stapling device, with reference to the drawings, wherein: 
         FIG. 1  is a side perspective view of a surgical stapling device including a powered actuation device and an exemplary embodiment of the presently disclosed tool assembly for leak resistant dissection of tissue; 
         FIG. 1A  is a side perspective view of a surgical stapling device including a manually operated actuation device and the presently disclosed tool assembly shown in  FIG. 1 ; 
         FIG. 2  is a top view of the tool assembly shown in  FIGS. 1 and 2 ; 
         FIG. 2A  is a top view of the cartridge assembly of the tool assembly shown in  FIG. 2  with the anvil removed; 
         FIG. 2B  is a cross-sectional view taken along section line  2 B- 2 B of  FIG. 2 ; 
         FIG. 2C  is a top view of another embodiment of the presently disclosed tool assembly; 
         FIG. 3  is a top view of tissue after a first cutting operation with the tool assembly shown in  FIG. 2 ; 
         FIG. 4  is a top view of the tissue after a second cutting operation with the tool assembly shown in  FIG. 2 ; and 
         FIG. 5  is a top view of the tissue after a third cutting operation with the tool assembly shown in  FIG. 2 ; 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The presently disclosed tool assembly for leak resistant dissection of tissue will now be described in detail, as part of a surgical stapling device, with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. In this description, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel, the term “proximal” is used generally to refer to the portion of the device that is closer to a clinician, and the term “distal” is used generally to refer to the portion of the device that is farther from the clinician. In addition, the term “endoscopic” is used generally to refer to endoscopic, laparoscopic, arthroscopic, and any other surgical procedure performed through a small incision or a cannula inserted into a patient&#39;s body. Finally, the term “specimen side” is used generally to refer to the side or portion of body tissue that is being removed from a patient during a surgical procedure. 
     The presently disclosed tool assembly is configured to minimize the likelihood of leaks at termination points along a cut line in body tissue. The tool assembly can be integrally secured to a distal end of a surgical stapling device, or in the alternative, form part of a disposable loading unit or reload that is releasably secured to the surgical stapling device. In addition, the configuration of the tool assembly may also be incorporated into both endoscopic and open-type surgical stapling devices. 
     In embodiments, the tool assembly includes an anvil and a cartridge housing a plurality of staples. The tool assembly, including each of the anvil and cartridge has a linear longitudinal proximal portion and a transverse distal portion. The linear proximal portion is substantially longer than the transversely extending distal portion. In embodiments, the distal portion of the tool assembly may be curved or define an angle with the linear proximal portion. In use, when a surgical procedure is performed that requires a plurality of cutting operations, e.g., a gastrectomy procedure, the first cutting operation is performed to form a substantially linear cut line having a curved distal portion that curves outwardly towards a specimen side of the tissue being operated on, e.g., the stomach. In each subsequent cutting operation, the proximal portion of the tool assembly is positioned in overlapping relation with the end of a linear portion of the existing cut line with a termination point of the existing cut line being curved or angled towards the specimen side of the tissue being partially removed. By positioning the termination points on the specimen side of the organ being operated upon, the termination points of the cut line are positioned on the specimen side and are removed from the patient with the tissue being removed. 
     Referring to  FIG. 1 , the presently disclosed tool assembly shown generally as  10  is suitable for use with known surgical stapling devices. In embodiments, the surgical stapling device  100  includes a powered handpiece  110 , an adapter  112  that extends distally from the powered handpiece  110 , and the tool assembly  10  supported on the distal end of the adapter  112 . The tool assembly  10  may be in the form of a disposable loading unit or reload  11  that is releasably coupled to the distal end of the adapter  112  using, for example, a bayonet-type coupling. Alternately, it is envisioned that the tool assembly  10 , the adapter  112 , and/or the powered handpiece may be integrally or non-removably secured to each other. U.S. Pat. No. 9,055,943 (“&#39;943 Patent”) discloses a surgical stapling device having a powered handpiece, an adapter, and a tool assembly that is releasably coupled to the adapter. The &#39;943 Patent is incorporated herein by reference in its entirety. 
     Referring to  FIG. 1A , in some embodiments, the surgical stapling device  200  includes a manually actuated hand piece  210 , an elongated body portion  212  extending from the handpiece  210 , and the tool assembly  10  coupled to the distal end of the elongated body portion  212 . As discussed above with regard to the stapling device  100  ( FIG. 1 ), The tool assembly  10  may be in the form of a disposable loading unit or reload  11  that is releasably coupled to the distal end of the elongated body portion  212  using, for example, a bayonet-type coupling. Alternately, it is envisioned that the tool assembly  10  and the elongated body portion  212  may be integrally or non-removably secured to each other. U.S. Pat. No. 5,865,361 (“&#39;361 Patent”) discloses a surgical stapling device having a manually actuated handpiece, an elongated body portion, and a tool assembly that is releasably coupled to the elongated body portion. The &#39;361 Patent is incorporated herein by reference in its entirety. The staple cartridge can be attached to the loading unit or stapler jaw, or the staple cartridge can be part of a removable and replaceable cartridge assembly. 
     Referring to  FIGS. 1-2 , the tool assembly  10  includes a pair of jaws  12 ,  14  including an anvil  12   a  and a cartridge assembly  14   a  that are movable in relation to each other between spaced and approximated positions. In embodiments, one of the jaws  12 ,  14  may be fixed in relation to the adapter  112  and/or body portion  212  and the other jaw  12 ,  14  may be movably supported for movement between the spaced and approximated positions in relation to the one jaw member. Alternately, both of the jaws may be movable in relation to the adapter  112  and/or body portion  212  between the spaced and the approximated positions. The adapter  112  and the elongated body portion  212  can be rotatable with respect to powered handpiece  110 /handpiece  210  along arrow AA 1  ( FIG. 1 )/AA 2  ( FIG. 1A ) to position the termination point along the opposite side. Depending on the surgical procedure and the location of the specimen side, this rotation can accommodate the surgeon. 
     Referring to  FIGS. 2-2B , each of the jaws  12 ,  14  defines a tissue contacting surface  16 ,  18 , ( FIG. 2B ), respectively, that is positioned in opposition with the tissue contacting surface of the other jaw when the jaws  12 ,  14  are in the approximated position to define a tissue gap “G” ( FIG. 2B ). The tissue gap “G” is dimensioned to clamp onto tissue to be stapled and cut by the tool assembly  10  as is known in the art. The &#39;361 Patent discloses a tool assembly configured to staple and cut tissue. 
     In embodiments, the tissue contacting surface  16  of the anvil  12   a  defines a plurality of staple deforming recesses  19  and an anvil knife slot  20  ( FIG. 2B ). In addition, the cartridge assembly  14   a  includes a staple cartridge  22  that defines staple pockets  24  that receive staples  26 . The staple cartridge  22  also defines a knife slot  28  ( FIG. 2B ). The knife slots  20  and  28  are aligned and receive a knife  30  of a drive member  32  to cut tissue clamped between the anvil  12   a  and cartridge assemblies  14   a  as is known in the art. The &#39;361 Patent discloses a tool assembly including a drive member and a knife. As such, these components will not be described in further detail herein. 
     The tool assembly  10  (and each of the jaw members  12 ,  14 ) includes a longitudinal portion  34  defining a first longitudinal axis “A” and a transverse portion  36  positioned contiguous with and distally of the longitudinal portion  34 . The transverse portion  36  may be curved outwardly away from the first longitudinal axis “A” a distance “X” from the termination point TS ( FIG. 2A ). Without wishing to be bound to a particular theory, the distance “X” is spaced to ensure that the entire staple line (opposite the specimen side) is spaced to intersect the cut line. Stated another way, depending on the number of rows in the staple line (i.e. 2 rows, 3 rows), the cut line will contain at least a portion of all rows of the staple line on the non-specimen side. In one embodiment, the distance “X” may be between about 1 mm and about 10 mm. In other embodiments, the distance “X” may be between about 4 mm and 8 mm. In other embodiments, the distance “X” may be between 1 mm and about 30 mm and any subranges in between. In addition, the transverse portion  36  may have a radius of curvature to define a transition of the first longitudinal axis “A” and “B” The transverse portion may form a corner “C” between the linear portion and the transverse portion. 
     When actuated, an operative portion “W” of the tool assembly  10  defines staple lines  40  and a cut line  42  ( FIG. 3 ) that extend along a substantial portion of the overall length of the tool assembly  10 . As used herein, the operative portion “W” means the portion of the tool assembly  10  that forms the staple lines  40  and cut line  42 . The longitudinal portion  34  of the operative portion “W” of the tool assembly  10  has a length “Y” and the transverse portion  36  has a length “Z”. The length “Y” forms a majority of the overall length of the operative portion “W” of the tool assembly  10 . In embodiments, the length “Y” is a greater percentage of the total length of the operative portion “W”. For example, in one embodiment, the length “Y” can be at least 80 percent of the total length of the operative portion “W”. In another embodiment, the length “Y” is at least 90 percent of the total length of the operative portion “W”. 
     Referring to  FIG. 2C , in an alternative embodiment, the transverse portion  36 ′ of the tool assembly  10 ′ is linear and defines a longitudinal axis “B” that defines an acute angle β with the axis “A” of the longitudinal portion  34 ′. In embodiments, angle β can have a value to ensure that the entire staple line (opposite the specimen side) is spaced to intersect the cut line. Stated another way, depending on the number of rows in the staple line (i.e. 2 rows, 3 rows), the cut line will contain at least a portion of all rows of the staple line on the non-specimen side. For example, angle β can be between about 15 degrees and about 60 degrees and in some embodiments is between about 20 degrees and 40 degrees and any subranges in between. 
     Referring to  FIGS. 3-6 , when a surgical procedure is performed that requires removal of tissue having a length greater than the length of the operative portion “W” ( FIG. 2A ) of the tool assembly  10 , it is necessary to operate the tool assembly  10  a plurality of times to fully separate the tissue from the patient. Each time the tool assembly  10  is actuated to cut and staple tissue, a distal end of each cut line  42   a ,  42   b , referred to herein as a termination points “T 1 ” and “T 2 ” ( FIG. 4 ), may not be perfectly sealed and may be subject to leakage. This greater likelihood of leakage occurs at the termination points “T 1 ” and “T 2 ” because the tool assembly  10  does not place a staple transversely across the termination points “T 1 ” and “T 2 ”. As described in further detail below, the presently disclosed tool assembly  10  allows a clinician to position the termination points “T 1 ” and “T 2 ” of a cut line  42  on the specimen side “S” of the tissue being operated upon to minimize the likelihood of leakage occurring in live tissue “LT” that remains within the patient. 
     In use, during a surgical procedure, e.g., a gastrectomy procedure, to remove tissue from a patient, e.g., a portion of the stomach  50 , the jaws  12  and  14  ( FIG. 1 ) of the tool assembly  10  are approximated about a portion of the stomach  50  and the surgical stapling device  100 ,  200  is actuated as known in the art to simultaneously cut and staple the tissue  50 . Prior to cutting and stapling the tissue  50 , a clinician positions the tool assembly  10  such that the transverse portion  36  of the tool assembly  10  angles or curves towards the specimen side “S” of the tissue  50  and the first termination point T 1  of the first cut line  42   a  is positioned on the specimen side “S” of the tissue  50  offset from an axis defined by the cut line  42   a.    
     After the first actuation of the surgical stapler  100 ,  200 , the disposable unit  11  ( FIGS. 1 and 1A ) is replaced with a new disposable loading unit  11  including a fresh cartridge. Alternately, a new stapling device with a fresh cartridge can be used. Next, the stapling device  100 ,  200  is positioned such that the longitudinal portion  34  of the tool assembly  10  is aligned with the distal end  60  ( FIG. 4 ) of the longitudinal portion of the existing cut line  42   a  and the transverse portion  36  of the tool assembly  10  is angled or curved outwardly from the longitudinal axis “A” towards the specimen side “S” of the tissue  50 . When the stapling device  100 ,  200  is actuated a second time to staple tissue and form a second cut line  42   b  ( FIG. 4 ), the first and second termination points T 1  and T 2  are positioned on the specimen side “S” of the tissue  50  offset from the longitudinal axis “A” of the first and second cut lines  42   a  and  42   b  or of at least the second cut line  42   b  if the cut line  42  ( 42   a  and  42   b ) is not straight. 
     If an additional actuation or actuations of the stapling device  100 ,  200  is/are required to fully dissect and remove the specimen side “S” of tissue  50  being operated on, the above-described step is repeated until the tissue is fully dissected and stapled and the tissue specimen “S” is removed. By performing the method described above with the presently disclosed tool assembly  10 , all of the termination points on the cut line  42  are confined to the specimen side “S” of the tissue  50  being operated upon. As such, the points along the cut line  42  most susceptible to leakage are removed from the patient with the specimen side “S” of the tissue  50  after the dissection of tissue is complete. 
     Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.