Eccentric surgical forceps

A surgical forceps which can be used for taking biopsy specimens internally is described having a compact configuration and very wide opening jaws, both of which are movable together by means of an elongated, flexible actuator member which operates directly only on one of the two end effectors containing the respective jaws. The forceps is particularly useful in conjunction with a surgical scope such as an endoscope or similar device.

FIELD OF THE INVENTION 
The present invention relates to surgical instruments, such as forceps 
having a distal assembly for performing internal surgical procedures 
involving cutting, grasping, and/or removing internal tissue. More 
particularly, the present invention relates to biopsy forceps, having 
articulated end effectors, for cutting and/or removing tissue samples. 
BACKGROUND OF THE INVENTION 
Surgical procedures involving the cutting, grasping, and/or removal of 
internal tissue are frequently performed using various forms of surgical 
forceps which may be passed into the body through an elongated, usually 
flexible tube, such as an endoscope, catheter, cannula, or trocar. 
Examples of endoscopes used in these procedures are laparoscopes, 
thorascopes, and arthroscopes. Typical of such forceps is a bioptome used 
to remove biopsy specimens internally. The bioptome includes a long 
flexible coil having a pair of opposed jaws at the distal end and a manual 
actuator at the proximal end. Manipulation of the actuator opens and 
closes the jaws. During biopsy tissue sample procedures, the bioptome, or 
other surgical instrument, is inserted into the narrow lumen of an 
endoscope while viewing the biopsy site through an optical scope. The 
surgeon guides the endoscope to the biopsy site until the opposed jaws 
arrive at the biopsy site. The surgeon then positions the jaws of the 
bioptome around the tissue to be sampled and manipulates the actuator so 
that the jaws close around the tissue. A sample of the tissue is then cut 
or torn away from the biopsy site while it is trapped between the jaws of 
the bioptome. Keeping the jaws closed, the surgeon then withdraws the 
bioptome from the endoscope and opens the jaws to disgorge the biopsy 
tissue sample. 
Because the lumen of the endoscope is usually relatively small, the 
bioptome inserted through the lumen must also be small and of compact 
configuration. Further, in order to achieve the necessary manipulation 
required to remove the sample and extract it through the lumen of the 
endoscope, the bioptome frequently has a fairly complex structure. Because 
of the size constraint and other limitations associated with the bioptome, 
the jaws typically open to a relatively narrow extent, thereby severely 
limiting the size and type of specimen that can be extracted. Some 
conventional bioptomes, for example, frequently employ a fixed jaw and a 
single movable jaw which closes against the fixed jaw. Other conventional 
bioptomes employ two movable jaws which are separately activated by 
complex, multi-link systems and which can only be opened to a relatively 
narrow extent. 
The same considerations and constraints generally apply for other surgical 
forceps used for cutting, grasping, and/or removing internal tissue. 
SUMMARY OF THE INVENTION 
It is therefore an object of the invention to provide a surgical instrument 
for internally cutting, grasping, and/or removing tissue, the instrument 
having end effectors with jaws that can open relatively widely once 
inserted into an internal body area. 
It is a further object of the invention to provide a surgical instrument 
for internally cutting, grasping, and/or removing tissue having end 
effectors with jaws that can be closed into a compact configuration to 
facilitate passage through the lumen of a surgical scope. 
Additional objects and advantages of the invention will be set forth in the 
description which follows and, in part, will be apparent from the 
description or may be learned by practice of the invention. The objects 
and advantages of the invention will be realized and attained by means of 
the elements and combinations particularly pointed out in the appended 
claims. 
To achieve the objects and in accordance with the purpose of the invention, 
as embodied and broadly described herein, the invention comprises a 
surgical instrument, such as a surgical forceps, having a distal assembly 
for cutting, grasping, and/or taking internal body tissue that includes a 
proximal actuator assembly and a distal end effector assembly having first 
and second end effectors in which the proximal end of the second end 
effector pivotally engages the first end effector intermediate its 
proximal and distal ends. The two end effectors thereby form a pair of 
movable jaws in which the second end effector pivotally engages with the 
distal end of a clevis at a point intermediate its length. The clevis has 
an axial passage therethrough to accommodate a slidable, elongated 
actuator whose distal end is pivotally attached to the proximal end of the 
first end effector which is also slidably disposed in the distal end of 
the clevis. The proximal end of the clevis is adapted for attachment to 
the actuator assembly, which includes a tubular sheath containing a 
slidable, elongated cable that engages the proximal end of the actuator to 
permit axial displacement of the actuator and the end of the end effector 
to which it is attached, to cause the two jaws of the device to open or 
close. 
It is to be understood that both the foregoing general description and the 
following detailed description are exemplary and explanatory and are 
intended to provide further explanation of the invention as claimed. 
The accompanying drawings are included to provide a further understanding 
of the invention and are incorporated in and constitute a part of this 
specification, illustrate embodiments of the invention and together with 
the description serve to explain the principles of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Reference will now be made in detail to the present preferred embodiments 
of the invention, examples of which are illustrated in the accompanying 
drawings. Whenever possible, the same reference numbers will be used 
throughout the drawings to refer to the same or like parts. 
The present invention is directed to an improved distal assembly for a 
surgical instrument and more particularly to surgical forceps having a 
distal assembly, for example, for taking biopsy specimens, and including a 
pair of end effectors that are interconnected to form a pair of jaws that 
can be widely opened and retracted to form a compact, linear unit that is 
compatible with the lumen of a surgical scope while also permitting wide 
opening of the jaws to facilitate their use once in place internally in a 
body. 
The device of the invention can be employed in connection with various 
surgical scopes, trocars, cannulas, or catheters for removing, grasping, 
or cutting tissue specimens internally. Further, the distal assembly 
described herein is not limited in its application to surgical forceps, 
but can also be incorporated in other surgical devices having opposed jaws 
or cutting surfaces. Typical of devices useful in the invention are 
various graspers, surgical scissors, dissectors, clamps, and forceps. 
FIG. 1 of the drawings illustrates the distal assembly incorporated in 
surgical forceps in accordance with the present invention. The distal 
assembly 1 includes a clevis 2 having an actuator rod 7 slidably disposed 
within it and two end effectors 3 and 5 with opposing end portions 4 and 6 
which, in the illustrated embodiment, are cup-shaped jaws having 
sufficiently sharp edges to facilitate the cutting, grasping, and removing 
of tissue samples when the respective end portions 4 and 6 are brought 
together by axial displacement of the actuator rod 7 whose distal end 
pivotally engages the proximal end of end effector 3 disposed within the 
clevis. 
FIG. 2 of the drawings illustrates the side of the surgical forceps of the 
invention opposite that shown in FIG. 1 and, in particular, illustrates 
the off-set, pivotal engagement of the proximal end of end effector 5 with 
end effector 3 at pivot point 8 intermediate the proximal and distal ends 
of end effector 3 resulting in pivot point 8 being out of axial alignment 
with actuator 7 in clevis 1 when the end effectors 3 and 5 are open as 
shown. When the end effectors 3 and 5 are closed together as shown in 
FIGS. 4 and 5, pivot point 8 is in axial alignment with the actuator 7 
within the clevis 2. 
The internal configuration of the distal assembly of the invention is shown 
in FIGS. 3 and 6, which are internal side views corresponding to FIG. 1. 
Distal assembly 1 includes an elongated clevis 2 having a distal end 14 
and a pair of engaging end effectors 3 and 5. The shorter of the two end 
effectors 5 is pivotally attached at pivot point 10 to the distal end 14 
of the clevis and also pivotally attached at pivot point 8 to the other 
end effector 3. As shown in FIG. 6, a cut-out slot 16 in effector 3 
accommodates pivot point 10 when the end effectors are closed. End 
effector 3, which is the longer of the two end effectors, has a pivotal 
engagement at pivot point 9 with the distal end of actuator rod 7 which is 
slidably disposed within the clevis 2. Both of the end effectors 3 and 5 
are provided with opposing end cups 4 and 6. The distal end of flexible, 
tubular sheath 11 is adapted to engage by any appropriate, known means, 
such as threading or fixed attachment, with the proximal end of clevis 2 
and contains an elongated actuator cable 12 slidably disposed therein. 
Flexible cable 12 engages within channel 17 of actuator rod 7 to enable 
axial sliding movement of actuator rod 7 within the clevis 2 in response 
to axial movement of the actuator cable 12. 
Movement of actuator rod 7 in the proximal direction (the direction of the 
arrow) causes movement in the proximal direction of the proximal end 15 of 
end effector 3. This axial movement by end effector 3, in the direction of 
the arrow, also causes pivotal rotation of end effector 3 around pivot 
point 8 and pivotal rotation of end effector 5 around pivot point 10 
thereby causing the end effectors cups 4 and 6 to close towards one 
another until end effectors 3 and 5 are in opposing alignment in a compact 
linear configuration as illustrated in FIG. 4. Similarly, movement of the 
actuator rod 7 in the opposite or distal direction with respect to clevis 
2 causes a sliding movement of proximal end 15 of end effector 3 which 
opens the jaws or end cups 4 and 6 of the device so that the opposing end 
effectors 3 and 5 are eventually widely separated. The various pivot 
points 8, 9, 10, and 22 are otherwise of conventional construction and can 
include, for example, any form of pin, bolt, or rotatable bearing. 
As shown in FIGS. 9 and 10, the proximal ends of sheath 11 and cable 12 
terminate conveniently in a manipulator 18 having a handgrip 23 including 
fixed grip 19 attached to barrel 24 and moveable grip 20 which pivotally 
engages the barrel 24 at pivot point 22. The distal end (not shown) of 
grip 20 engages the proximal end of cable 12 (not shown) within barrel 24 
such that movement of the proximal end of grip 20 toward or away from grip 
19 results in axial movement of cable 12 within barrel 24 and tubular 
sheath 11 whose proximal end is attached by retainer 21 to barrel 24. 
Other forms of manipulators known in the art can also be employed to 
effect axial movement of cable 12 thereby opening or closing the jaws of 
the end effectors. For example, hand-grip 23 may be a conventional 
bioptome actuation device whose construction and operation are fully 
described in U.S. Pat. No. 5,542,432 to Slater et al., the complete 
disclosure of which is hereby incorporated by reference. Similarly, sheath 
11 may be any conventional long, flexible coil-like section well known in 
the art for connecting a proximal handle to a distal end effector 
assembly. For example, the bioptome disclosed in the Slater et al. patent 
uses a long, flexible, and hollow coil with a control wire extending 
therethrough to couple the handle to an end effector assembly. The hollow 
coil may be manufactured from 304 steel wire by forming the wire over a 
mandrel. The use of the distal assembly described herein, however, is not 
limited to the actuation assembly disclosed in Slater et al. or any 
specific type of coil, and may be used in connection with various other 
actuation assemblies and coils known in the art. 
As noted, FIG. 4 of the drawing is an internal view of the surgical forceps 
of the invention in collapsed configuration. The two opposing cups or jaws 
6 and 4 are pressed against one another and the two end effectors 3 and 5 
are in close alignment substantially within the confines of the clevis 2. 
FIG. 5 of the drawings further illustrates from the bottom the closed 
configuration of the surgical forceps of the invention. (FIGS. 4 and 5 do 
not show the tubular sheath 11 shown in FIGS. 8 and 9.) 
FIG. 11 of the drawings illustrates the surgical biopsy forceps of the 
invention in the open configuration as viewed from the front of the 
device. 
FIG. 12 of the drawings illustrates an alternate embodiment of the 
invention whereby the distal end 15 of end effector 3 is further 
stabilized and guided during its axial displacement within clevis 2 by 
providing a slot 26 in the side of the clevis to accommodate a pin 9 on 
the proximal end of the effector 3. 
The distal assembly of the invention, because of its unique engagement of 
the end effectors with each other and with the actuator rod within the 
clevis, whereby the first effector is directly attached to the actuator 
rod while the second end effector has a pivotal attachment between the 
ends of the first end effector, achieves a compact, linear collapsed 
configuration, compatible with an interior lumen of surgical scopes or 
similar devices. The extremely wide opening of the end effectors in the 
open configuration of up to about one hundred twenty degrees as shown, for 
example, in FIG. 3, greatly facilitates the taking of tissue specimens. 
Further, the avoidance of a direct connection between the actuator rod and 
the second effector while achieving opening and closing movement of both 
effectors permits fewer and less complex linkages and reduced size while 
preserving the advantages of two widely opening, actuated jaws. 
The improved distal assembly of the invention has been described in 
connection with a bioptome having jaws for taking biopsy samples. It is to 
be understood that other types of end effectors, including end effectors 
for clamping or cutting tissue or performing any other appropriate 
surgical procedure, may be modified for use in accordance with the present 
invention. The end effector described herein is illustrative only of one 
preferred embodiment of the invention. 
It will be apparent to those skilled in the art that various modifications 
and variations can be made in the assembly of the present invention 
without departing from the scope or spirit of the invention. Other 
embodiments of the invention will be apparent to those skilled in the art 
from consideration of the specification and examples should be considered 
as exemplary only, with a true scope and spirit of the invention being 
indicated by the following claims.