Load assist device for a suture cartridge

A load assist device for facilitating the loading of a suture cartridge onto a cartridge carrier of a surgical instrument is disclosed. The device has a cartridge casing and a suture cartridge loaded into an interior storage space of the cartridge casing. The suture cartridge contains a suture filament for tying a surgical knot. When a cartridge carrier of a surgical instrument is inserted into an aperture for receiving the cartridge within the cartridge casing, the carrier passes through a carrier channel inside the casing until it reaches the cartridge storage space for loading the suture cartridge onto the cartridge carrier. The loaded cartridge carrier may then be withdrawn from the cartridge storage space for withdrawal from the cartridge casing. The device helps the surgeon or the operating room assistant with loading a suture cartridge onto a surgical instrument for the eventual deployment of a knot during surgery, and avoids some of the pitfalls inherent in loading, unloading and reloading suture cartridges onto the surgical instruments during procedures where it is necessary or desirable to place several knots for fastening tissue.

BACKGROUND OF THE INVENTION 
This invention relates to an assembly for facilitating the placement of a 
surgical knot made from a suture filament. In particular, the invention 
relates to such an assembly which is particularly adapted for deployment 
of the knot during minimally invasive surgical procedures where access to 
the surgical site is limited. 
A mainstay of surgical practice has been and will continue to be the 
formation and placement of surgical knots from suture filament to fasten 
tissue during an operative procedure. Numerous surgical knots have been 
developed over an appreciable period of time, and the art of forming and 
tying knots for surgical applications is a critical skill which a surgeon 
must possess to perform an operation safely and efficiently. Accordingly, 
the art is extensively developed. See, for example, Tissue Approximation 
in Endoscopic Surgery, Alfred Cuschieri, Zoltan Szabo, Times Mirror 
International Publishers, 1995, which describes numerous surgical knots 
made from suture filament to facilitate the approximation of tissue during 
surgery. 
The art of surgical knots is also well represented in the patent 
literature. U.S. Pat. No. 2,012,776 discloses a surgical instrument for 
facilitating the placement of various forms of slip knots made from 
surgical filament. The inventor named on the '776 patent, H. A. Roeder, 
developed the "Roeder Knot" which is a surgical knot which is frequently 
used in practice today. More recently, U.S. Pat. No. 5,573,286 discloses a 
surgical knot of suture strand particularly adapted for orthopedic 
applications. The preferred embodiment described in the '286 patent is 
directed to tying the knot to a bone. 
Early on, it was recognized that the deployment and placement of surgical 
knots within a remotely accessible surgical site could be difficult, 
cumbersome and often unreliable. Accordingly, instrumentation was 
developed to facilitate the placement of knots in remote locations. 
Cleverly, a pre-tied knotted loop of suture was often used to reduce the 
number of steps required to form the tightened knot. For example, U.S. 
Pat. Nos. 2,566,625 and 3,090,386 describe surgical devices which are 
adapted to support a pre-tied knotted loop of suture for suturing or 
ligating tissue, particularly during procedures where the tissue desired 
to be manipulated is difficult to access. 
More recently, instrumentation has been developed for facilitating the 
placement of knots particularly during minimally invasive surgical 
procedures. In particular, U.S. Pat. No. 5,320,629 discloses the formation 
of a pre-tied knotted loop of suture, and the placement of the pre-tied 
knotted loop on a surgical device for facilitating the tightening of the 
loop to approximate tissue during endoscopic surgical procedures. German 
Patent No. 912619 also discloses a device similar to that disclosed in the 
'629 patent. 
Although the art of surgical knots is well developed, and surgical devices 
for facilitating the placement of tightened knots from a pre-tied knotted 
loop of suture have also been developed for application at remote surgical 
sites, there are problems which still need to be addressed. In particular, 
in those surgical procedures where access to the site is limited, for 
example during minimally invasive procedures such as endoscopic surgical 
procedures, the knots can be difficult to deploy. Frequently, the knots 
which can be deployed are routinely slip knots having poor knot security. 
If knot security is poor, then the approximated tissue may not be held for 
a sufficient period of time to promote adequate wound healing. 
Additionally, during minimally invasive procedures, the pre-tied knotted 
loops of suture which have been described in the prior art devices can be 
difficult to efficiently tighten for final deployment. 
Therefore, in minimally invasive surgical procedures where access to the 
surgical site is limited, what is needed is an assembly for facilitating 
the formation of a surgical knot. The assembly should be relatively simple 
in construction and should be compatible with a partially tied surgical 
knot. The assembly should facilitate the conversion of the partially tied 
knot into a fully formed knot which can provide a consistently strong knot 
security each time the knot is placed to enable even an inexperienced 
surgeon to confidently and efficiently place a secure suture knot. 
Additionally, it would be desirable if it were possible to easily retrofit 
the assembly onto various surgical instruments, particularly endoscopic 
instruments, for ease of use of the assembly to place surgical knots. 
Finally, it would be helpful if it were possible to reload the assembly 
with a second partially tied knot following deployment of the first knot 
so that the assembly can be used to place multiple knots. 
In addition, what is needed is a device to facilitate the loading of a 
suture cartridge assembly onto a surgical instrument. Specifically, what 
would advance the state of the surgical art would be a device which aids 
the surgeon to load the assembly onto a surgical instrument for deploying 
a surgical knot from the suture filament contained in the assembly, and to 
easily reload the instrument with a second suture cartridge assembly after 
the first spent assembly has been removed from the instrument. It would 
also be advantageous if such a device could be designed to avoid the need 
for the user to handle a needle when attached to the filament and to be a 
suitable container for shipping and storage of the suture cartridge when 
used in conjunction with the other packaging materials. 
SUMMARY OF THE INVENTION 
The invention is a load assist device for facilitating the loading of a 
suture cartridge onto a cartridge carrier of a surgical instrument. The 
device comprises a cartridge casing and a suture cartridge. 
The cartridge casing of the device has an interior cartridge storage space 
within the casing. It also has a carrier aperture and an interior carrier 
channel defining a passageway between the carrier aperture and the storage 
space. 
The suture cartridge of the device is loaded into the interior storage 
space of the cartridge casing. The cartridge contains a suture filament 
for tying a knot during a surgical procedure. A surgical needle may be 
attached to the distal end of the suture filament, in which case the 
device is useful for the protection of the user from the needle point. 
The cartridge carrier of the surgical instrument may be inserted into the 
carrier aperture of the cartridge casing for passage through the carrier 
channel in a loading direction to the cartridge storage space for loading 
the suture cartridge onto the cartridge carrier. Subsequently, the loaded 
cartridge carrier may be withdrawn from the cartridge storage space for 
passage through the carrier channel in an unloading direction for 
withdrawal from the carrier aperture. 
The load assist device of this invention aids the surgeon or operating room 
assistant with loading a suture cartridge containing a suture filament for 
tying a surgical knot onto a carrier of the surgical instrument. In so 
doing, the loading and unloading of cartridges onto the surgical 
instrument becomes easier, thus saving time, mishaps and annoyance. The 
load assist device facilitates loading the cartridge onto a carrier of the 
surgical instrument, and therefore makes it easier to load a second 
cartridge onto the carrier after a first spent cartridge is disposed of. 
In addition, the load assist device not only prevents inadvertent needle 
puncture when a needle is attached to the suture filament, but also 
provides a suitable container for shipping and storage of the suture 
cartridge when used, transported and manipulated with other packaging 
materials. 
The load assist device of this invention can be used in any surgical 
procedure where it is necessary or desirable to load a suture cartridge 
onto a carrier of a surgical instrument to place surgical knots for 
suturing bodily tissue. Therefore, the device will find uses in a whole 
host of applications, including conventional open surgical procedures as 
well as minimally invasive procedures where access to the surgical site is 
limited. The assembly may be especially useful for the augmentation of the 
esophagogastric sphincter muscle to repair the symptoms of 
gastroesophogeal reflux disease (GERD), particularly when the procedure is 
desired to be accomplished minimally invasively. During this procedure , 
the stomach must be sutured to itself and the esophagus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1-6 illustrate how a partially tied surgical knot can be made from a 
length of suture filament. The partially tied knot thus formed can be used 
in the practice of the specific embodiments of this invention illustrated 
hereinafter. Of course, other partially tied knots can be used in the 
practice of this invention. 
The suture filament 30 shown in FIG. 1 can be composed of any suture 
material currently used or hereafter developed. The suture filament may be 
a monofilament suture or a multifilament, braided suture. The suture 
filament, regardless of construction, may be non-absorbable or 
bio-absorbable, depending on the particular application for which the 
suture is being used to fasten tissue. 
The length of suture filament 30 has proximal and distal ends, 31 and 32, 
respectively. Adjacent the proximal end, there is a proximal length 33 of 
suture filament. Correspondingly, adjacent the distal end of the suture 
filament, there is a distal length 34 of the suture filament. 
As shown in FIG. 2, a first loop 35 is formed by manipulating the distal 
length 34 of the suture filament. Now looking at FIG. 3, while the 
proximal length 33 of the suture filament remains fixed, the distal length 
is manipulated to form a second loop 36 wrapped generally transversely 
around the first loop 35. Third and fourth loops, 37 and 38, respectively, 
are likewise formed about the first loop as depicted in FIG. 4. The 
second, third and fourth loops are generally parallel to each other and 
are oriented generally transversely to the first loop. For purposes of 
describing this partially tied knot, these loops may be referred to 
collectively as the "knot loops". The number of knot loops may vary 
depending on the particular application for which the knot is used. In the 
illustrated embodiment, the second, third and fourth loops together form a 
common loop core 39 which receives the first loop 35. 
Reviewing FIG. 5, the loosely formed knot is tightened by applying tension 
on the distal length 34 of the suture filament. In so doing, the second, 
third and fourth loops tighten down on the first loop, and thus the first 
loops is securely received in the common loop core. 
As depicted in FIG. 6, a tissue-fastening loop 40 can be formed by passing 
the distal end 32 and the distal length 34 of the suture filament through 
the first loop 35. 
To form the knot, the partially tied knot of FIG. 6 is taken, and tension 
on the proximal length 33 of the suture filament is applied in the 
proximal direction as indicated by the arrow in FIG. 7. To facilitate 
forming the knot, the surgeon ideally holds his fingertips against the 
proximal side of the knot loops while tension is applied to the proximal 
length 33 of the suture filament. Alternatively, as described in the 
embodiments below, an instrument can be used to hold the knot loops in 
place. As tension is applied, the first loop 35 begins to be pulled 
through the common loop core 39 of the knot. When the first loop has 
sufficiently diminished in size from that shown in FIG. 6, it snares the 
distal length 34 of the suture filament. With continuing proximal tension 
on the proximal length of the suture filament, the first loop and the 
distal length of filament are pulled through the common loop core 39. When 
the first loop and distal length of filament emerge from the fourth loop 
38, an audible "clicking" sound may alert the user that the completed knot 
has been formed. 
Although the partially tied knot illustrated in FIG. 6, often referred to 
as a "blood" knot, is the preferred partially tied knot for conversion 
into the fully formed, non-slip knot which is used in the practice of this 
invention, other slip knots described in the literature can be used. The 
key characteristic for the acceptability of other partially tied knots is 
a common loop core (exemplified in FIG. 6 as common loop core 39) allowing 
passage of suture filament through the core. See, for example, The 
Encyclopedia of Knots and Fancy Ropework, R. Graumont and J. Hensel, 
Fourth Edition, Cornell Maritime Press. Suitable partially tied knots are 
shown in this book as numbers 102, 185, 227 and 349 on pages 71, 83, 87 
and 102, respectively. 
As depicted in FIG. 8, the completed surgical knot is a non-slip knot 41. 
The first loop has been eliminated, and a distal loop 42 positioned 
adjacent to the fourth loop 38 is formed from a portion of the distal 
length of the suture filament. The tissue loop 40, which is used to fasten 
tissue, consequently becomes rigidly fixed and secure. Tension applied to 
the loop 40 due to the tendency of the fastened tissue to expand or pull 
apart may result beneficially in further tightening of the non-slip knot. 
Referring to FIGS. 9 and 10, there is shown the formation of the partially 
tied knot depicted in FIGS. 1-6, formed about a core tube 43. The core 
tube facilitates the placement of the partially tied knot adjacent tissue 
desired to be fastened, as well as the conversion of the partially tied 
knot into the completed non-slip knot shown in FIG. 8. The core tube has 
proximal and distal ends, 44 and 45, respectively. A surgical needle 46 is 
attached to the distal end 32 of the surgical filament. The proximal 
length 33 of the filament is passed through the core tube. The length of 
suture filament exceeds the length of the core tube so that the proximal 
length of the suture filament may extend from the proximal end 44 of the 
core tube. Additionally, a sufficient amount of suture filament 
represented by its distal length 34 exits the distal end of the core tube 
so that it is possible to form the partially tied knot about the distal 
end 45 of the core tube. The first loop 35 and the subsequent knot loops 
represented by the second, third and fourth loops, 36, 37 and 38, are 
formed about the distal end of the core tube. Once formed, tension is 
applied to the distal length of the filament to tighten the knot loops 
about the distal end of the core tube. 
The partially tightened knot formed about the core tube can be loaded into 
a suture cartridge 47 as illustrated in FIG. 11. The suture cartridge has 
an elongated body 48. It also has top and bottom faces 78 and 79, 
respectively. A tube slot 49 for receiving the core tube 43 is embedded in 
the body of the cartridge between the top and bottom faces. The body also 
contains a knot recess 50 which has a pair of stripping shoulders 51. 
Extending from a proximal edge 52 of the tube slot in a proximal direction 
is a filament slot 53. Correspondingly, extending from a distal edge 54 of 
the tube slot toward a distal end of the cartridge body is a loop slot 55. 
The length of the core tube, designated as L.sub.1 in FIG. 11, is less 
than the length of the tube slot, designated as L.sub.2 in FIG. 11. 
When the partially tied knot is formed about the core tube 43, the knot 
loops are wrapped about the distal end 45 of the core tube. The free 
proximal end of the suture filament extends from the proximal end 44 of 
the core tube. The first loop 35 of the partially tied knot extends from 
the distal end of the core tube. When the core tube is loaded into the 
tube slot 49 of the cartridge body between the top and bottom faces, the 
knot loops sit inside the knot recess and abut the stripping shoulders of 
the knot recess. A portion of the proximal length 33 of the suture 
filament rests in the filament slot 53 embedded in the body of the 
cartridge, and the remaining portion of the proximal length of the suture 
filament extends from the proximal end of the cartridge body. 
Correspondingly, the first loop 35 of the partially tied knot and the 
distal end 34 of the surgical filament are received in the loop slot 55. A 
substantial portion of the first loop and the distal length of suture 
filament descend from the bottom face 79 of the cartridge body. In its 
original position as best illustrated in FIG. 13, the distal end 45 of the 
core tube is adjacent the distal edge 54 of the tube slot. Since the tube 
slot 49 has a length greater than that of the core tube 43, the core tube 
is capable of sliding proximally toward the proximal edge 52 of the tube 
slot. In this position, the knot is trapped in recess 50. The surgeon can 
then easily manipulate needle 46 and suture filament 34 without danger of 
prematurely deploying the knot. 
When the core tube is loaded into the tube slot within the body of the 
cartridge, a cartridge top 56 can be mounted onto the top face 78 of the 
cartridge body 48 as shown in FIG. 12. When the cartridge top is mounted, 
the core tube 43 is fully enclosed within the cartridge. 
With the core tube fully enclosed within the suture cartridge, the 
partially tied knot wrapped about the core tube can be deployed to fasten 
desired bodily tissue as illustrated in FIGS. 14-15. The first step is to 
position the suture cartridge 47 adjacent bodily tissue 57 desired to be 
fastened. Next, the surgical needle 46 is passed through the tissue, and 
into and through the first loop 35 to form the tissue loop 40. The size of 
the tissue loop is adjusted to provide the appropriate tension on the 
opposed tissue sections of the bodily tissue 57 desired to be fastened; 
once the knot is completed to from the non-slip knot, the tissue loop 
becomes rigidly fixed and further adjustment is unavailable. When the 
tissue loop 40 is formed and appropriately sized, proximal tension is 
applied to the proximal length 33 of the suture filament in the direction 
of the arrow as depicted in FIG. 15. The completed knot is formed when 
sufficient tension is felt or applied to the proximal length 33. 
Advantageously, when tension is applied to the proximal length 33 of the 
filament, the first loop is pulled and eventually applies a proximal force 
against the distal end 45 of the core tube 43, causing it to slide 
proximally as shown in FIG. 15. Since the knot loops abut against the 
stripping shoulders in the knot recess 50, the knot loops remain 
stationary even though the core tube slides proximally. When the core tube 
slides to a position where it is adjacent the proximal edge 52 of the tube 
slot 49, the knot loops are stripped from- the distal end 45 of the core 
tube. The knot is then fully formed, and the user can remove the cartridge 
top 56, cut the remaining proximal and distal lengths of suture filament, 
and remove the core tube. Alternatively, the proximal and distal lengths 
of suture filament can be exposed without removing cartridge top 56 by 
releasing the tension on proximal length 33 and pulling the cartridge 
proximally, thus allowing a portion of the proximal and distal lengths of 
suture filament contained in the core tube 43 to extend distally from 
recess 50. 
The suture cartridge 47 is advantageous because it is readily adaptable to 
conventional open and endoscopic instruments, and thus readily facilitates 
the formation of the knot. The suture cartridge may be disposable, or it 
can be used on multiple patients. When used on multiple patients, a 
plurality of disposable core tubes, including the partially tied knot 
wrapped about the tube, can be loaded serially into the suture cartridge 
to provide for the placement of numerous surgical knots to fasten tissue 
using a single suture cartridge. 
In another example utilizing the core tube concept, the partially tied knot 
is wrapped about the core tube to facilitate the conversion of the knot to 
the completed, non-slip knot to fasten tissue. This similar embodiment is 
illustrated in FIGS. 21-23. The one key difference between what is shown 
here and that illustrated in FIGS. 9-15 is that the core tube has a 
tapered distal end. For convenience, the same numbers have been used to 
identify component parts in FIGS. 21-23 as those used in FIGS. 9-15. 
Another example of a partially tied surgical knot is illustrated in FIGS. 
16-17. The knot is made from a suture filament 58 which has a proximal end 
59 and a distal end 60. A surgical needle 61 is attached to the distal 
end. The distal end of the filament is manipulated to form the knot while 
the proximal end of the filament is held stationary. A core loop 62, 
proximal loop 63 and first loop 64 are initially formed. The proximal loop 
is at a first end 70 of the knot, and the first loop is at an opposite end 
71 of the knot. The core loop is situated between the first and opposite 
ends of the knot. Knot loops, in the preferred embodiment consisting of 
second, third and fourth loops, 65, 66, and 67, are formed about the 
proximal loop 63 and the first loop 64. The knot loops together form a 
common loop core 68. The core loop is positioned within the common loop 
core. When tension is applied to the distal end of the surgical filament 
while the proximal end of the knot loops is supported, the knot loops are 
tightened. The knot loops are tightened about the first loop, proximal 
loop and core loop. When tightened, as shown in FIG. 17, the first loop, 
core loop and proximal loop are securely received in the knot loops, and 
the partially tied knot is formed. 
Referring specifically to FIG. 17, the core loop 62 has a free proximal end 
69 extending from the common loop core 68 toward the first end 70 of the 
knot. The core loop has a loop end 72 which extends from the common loop 
core in an opposite direction toward the opposite end 71 of the knot. The 
loop end 72 of the core loop 62 is disposed inside the first loop 64. 
The partially tied knot of FIG. 17 can be converted to a completed non-slip 
knot when axial tension is applied to the proximal loop in the proximal 
direction while the proximal end of the knot loops is supported. In a 
manner similar to the deployment of the knot best illustrated in FIGS. 
1-8, the knot is converted when the first loop is pulled through the 
common loop core to form a distal loop. Advantageously, when tension is 
applied on the proximal loop, not only is the first loop pulled through 
the common loop core, but also the core loop is pulled through as well. 
This provides an advantage because the core loop creates a sufficient 
space represented by the common loop core to enhance the ease of passage 
of the first loop through the common core to form the completed knot. 
Easier passage reduces the amount of tension which is needed to be applied 
to the proximal loop to form the completed knot, and therefore increases 
the degree of control of the user when the knot is being deployed. 
FIGS. 18-20 illustrate the use of the knot depicted in FIG. 17 to fasten 
tissue, where the knot is deployed in combination with a stripping tube 
73. When the partially tied knot of FIG. 17 is formed, the proximal loop 
63 is passed through the stripping tube. A portion of the proximal loop 
extends from a proximal end of the stripping tube. The proximal loop is 
passed through the stripping tube until the knot loops abut against the 
distal end of the stripping tube. Significantly, the stripping tube has a 
tapered distal end 74. The core loop and the first loop extend away from 
the tapered distal end of the tube. The opening at the distal end of the 
tube is smaller in diameter than the diameter of the knot loops. 
Consequently, when tension is applied on the proximal loop in the proximal 
direction, the knot loops will not pass into the stripping tube. 
The conversion of the partially tied knot to the completed knot is 
performed in a manner substantially similar to that described in 
connection with the conversion of the previously illustrated knot depicted 
in FIG. 6. 
Referring now to FIGS. 19-20, the stripping tube 73 is positioned adjacent 
bodily tissue 75 desired to be fastened. The surgical needle 61 is drawn 
through the tissue. A tissue loop 76 is formed when the surgical needle 
and distal end of the filament are fed through the first loop 64. Again, 
it is important to adjust the size of the tissue loop to provide for 
appropriate tensioning of the fastened tissue before the knot is fully 
deployed. When the desired tissue loop is formed, tension on the proximal 
loop 63 is applied in the proximal direction as indicated by the arrow in 
FIG. 19 to pull the core loop 62 and the first loop 64 through the common 
loop core. When the first loop emerges from the fourth knot loop 67, the 
distal loop 77 is formed, and the completed, non-slip knot has been 
created. 
The preferred embodiment of a suture cartridge assembly which can be used 
in the practice of this invention is detailed in FIGS. 24-39. The 
preferred embodiment is a further refinement of the assembly illustrated 
in FIGS. 11-15 which includes the partially tied surgical knot wrapped 
about a core tube, and subsequently loaded into a suture cartridge. 
Referring initially to FIGS. 24 and 25, the preferred suture cartridge 
assembly 80 includes a suture filament 81 with proximal and distal ends, 
82 and 83, respectively, configured into a partially tied surgical knot 84 
wrapped about a core tube 85. The proximal end of the suture filament 
extends from a proximal end of the core tube, a first loop 86 of the 
surgical filament extends from a distal end of the core tube, and a 
surgical needle 87 is attached to the distal end of the surgical filament. 
The suture cartridge has top and bottom faces, 88 and 89, respectively, and 
a slot 90 for receiving the core tube, including the suture filament with 
its partially tied knot wrapped about the core tube, between the top and 
bottom faces of the cartridge. The slot contains a knot recess 91 for 
receiving the partially tied knot of the suture filament, and the 
partially tied knot abuts a pair of stripping shoulders 92 within the knot 
recess. When the core tube is loaded into the slot, a portion of the 
distal end of the suture filament including the surgical needle and the 
first loop descend from the bottom face of the cartridge. A cartridge top 
93 covers the top face of the suture cartridge, and therefore encloses the 
core tube and a portion of the suture filament. 
Importantly, a grasping jaw 94 is pivotally attached to the suture 
cartridge at a pivot pin 99A. The grasping jaw faces the cartridge top and 
is moveable from an open position spaced from the cartridge top to a 
closed position adjacent the cartridge top. The grasping jaw is biased in 
its open position. A cartridge housing 99A which includes a suture 
filament track 96 is also mounted to the proximal end of the suture 
cartridge. 
Referring now to FIGS. 28-32, the details of the suture cartridge and the 
cartridge housing integrally mounted to the suture cartridge can be seen. 
The distal end of the cartridge contains a retaining pin 97 for 
permanently attaching the cartridge top 93 to the top face of the 
cartridge. The retaining pin is "heat-staked" to attach the cartridge top 
to the cartridge. Also included at the distal end of the cartridge is a 
locating boss 98. There is a pin orifice 99 for receiving the pivot pin 
for pivotally attaching the grasping jaw to the cartridge. The pivot pin 
received through the orifice also serves to fix the cartridge housing to 
the suture cartridge. A central aperture 100 is contained at the distal 
end of the cartridge housing to provide an opening for receiving the 
proximal end of the grasping jaw. Also contained within the cartridge 
housing is a torsion spring slot 101 for receiving a torsion spring 102 
(see FIGS. 24 and 33) to bias the grasping jaw in its open position. The 
torsion spring has an upper arm 113, a torsion loop 114 and a jaw arm 115. 
The suture filament track 96 of the cartridge housing includes a ventral 
channel 103 which merges into a left side suture groove 104 extending 
proximally to the proximal end of the cartridge housing. At the proximal 
end of the cartridge housing, a pair of lateral filament slots 105 are 
displayed. Continuing from the lateral filament slots, a right side suture 
groove 106 is embedded within the cartridge housing. The cartridge housing 
also contains a hook slot 107 surrounded by a pair of spaced-apart hook 
tines 108. 
Referring now to FIGS. 34-36, the details of the grasping jaw 94 can be 
seen. The grasping jaw has an inner serrated surface 109 to facilitate the 
grasping of tissue, suture filament or the surgical needle. It contains a 
jaw lug 110 including a jaw orifice 111 for receiving the pivot pin 95 for 
its pivotal mount relative to the suture cartridge. It also includes a 
spring arm slot 112 for receiving the torsion spring 102. The proximal end 
of the cartridge top has a spring tab 116. The spring tab biases and 
maintains core tube 85 distally during assembly and knot deployment. 
In the preferred embodiment, the suture cartridge assembly is a disposable 
assembly intended to be discarded after a single patient use. The suture 
cartridge and the housing are preferably composed of a biocompatible, 
injection-molded plastic, and the grasping jaw is preferably made from 
medical grade stainless steel. Alternatively, the suture cartridge 
assembly could be fabricated from a suitable metal in a metal injection 
molding (MIM) process, which is a conventional forming technique adaptable 
for fabricating conventional staple cartridges for surgical staplers and 
cutters. 
FIGS. 26 and 27 illustrate how the core tube is mounted into the suture 
cartridge, and how the proximal end of the suture filament is wrapped 
about the periphery of the cartridge housing within the suture filament 
track. As the core tube is mounted into the slot in the cartridge, the 
surgical needle and a portion of the distal end of the suture filament are 
passed through the slot, and the partially tied surgical knot is 
positioned into the knot recess where the knot abuts against the stripping 
shoulders and the first loop descends from the bottom face of the 
cartridge. The proximal end of the suture filament is passed through the 
ventral channel of the cartridge housing and is wrapped about the left 
side suture groove, lateral suture slots and right side suture groove of 
the suture filament track before emerging at an anchor recess 117 within 
the cartridge housing. A knot anchor 118 is tied at the proximal end of 
the suture filament within the anchor recess to place the suture filament 
in a fixed position within the cartridge housing. Also worthy of note in 
observing FIGS. 26 and 27 are the pair of retaining slots 119 at a 
junction between the cartridge housing and the top face 88 of the suture 
cartridge for further retaining the cartridge 93 top when it is mounted 
onto the top face of the suture cartridge. 
In an especially preferred embodiment, the loaded suture cartridge assembly 
which can be used in the practice of this invention is received within a 
cartridge carrier 120 of a surgical instrument 121 to further facilitate 
the deployment of the knot and the grasping of tissue, the surgical needle 
or the filament. Referring specifically to FIG. 33, the suture cartridge 
including the cartridge housing is loaded into and received within the 
cartridge carrier. The cartridge carrier has a pair of containing walls 
122 defining a channel 123 for receiving the cartridge assembly. Each 
containing wall has a top edge surface 124, and a serrated edge surface 
125 at its distal end. The surgical instrument which includes the 
cartridge carrier for receiving the suture cartridge advantageously 
includes a reciprocating closure tube 126 for urging the jaw to its closed 
position when the closure tube is reciprocated forwardly, and to its open 
position when the closure tube is reciprocated rearwardly. Such an 
instrument preferably includes a hook 127 which is received in the hook 
slot 107 between the pair of hook tines 108 in the cartridge housing. When 
the hook is retracted, it pulls the proximal end of the suture filament 
within the suture filament track 96 of the suture cartridge housing, and 
the knot is deployed in a manner substantially similar to that illustrated 
in FIGS. 11-15. 
Referring now to FIGS. 37-39, it can be observed that when the cartridge 
assembly is loaded into the carrier, the serrated edge surfaces of the 
containing walls of the cartridge carrier protrude from the cartridge top 
of the suture cartridge, and mesh with the inner serrated surface of the 
grasping jaw when the grasping jaw is in its closed position. In so doing, 
the meshing surfaces facilitate the grasping of tissue 128 (FIG. 37), the 
surgical filament 81 (FIG. 38) and the surgical needle 87 (FIG. 39). The 
suture cartridge assembly of this invention therefore facilitates not only 
the deployment of a fully formed knot from a partially formed knot, but 
also the manipulation of tissue or the suture filament including the 
surgical needle which is so important during the surgical procedure to 
easily place the knot. 
The load assist device of this invention, and the manner in which a 
cartridge carrier on a surgical instrument can be loaded with a suture 
cartridge contained in the load assist device, are illustrated in FIGS. 
40-49. 
Referring initially to FIGS. 40-42, the details of the load assist device 
can be seen. The load assist device 130 has a rigid and transparent 
cartridge casing 131, for ease of handling and to readily observe the 
contents within the casing when the cartridge carrier of the surgical 
instrument is loaded with the suture cartridge and removed from the 
transparent casing. The casing consists of a base 132 and a top cover 133 
facing the base. The top cover is releasably attached to the base. The 
cover has distal and proximal pins, 134 and 135, respectively, which are 
received in corresponding distal and proximal bosses, 136 and 137, on the 
base of the casing. To further secure the top cover to the base, a lower 
boss 138 on the base receives a corresponding lower pin (not shown) 
extending from the top cover, and a casing support rib 139 also extends 
from the top cover and frictionally engages the base. 
The cavity between the base and the top cover of the cartridge casing 
defines a cartridge storage space 140. The cartridge storage space 
includes a proximal retainer 141, a distal retainer 142 spaced from the 
proximal retainer, and a jaw retaining ledge 143 between the proximal and 
distal retainers. The cartridge storage space receives and secures the 
suture cartridge within the cartridge casing of the load assist device. 
The base and top cover of the cartridge casing also define a carrier 
aperture 144 for enabling the insertion and withdrawal of a cartridge 
carrier of a surgical instrument for deploying a knot during a surgical 
procedure from the suture filament contained in the cartridge. An interior 
carrier channel 145 provides a passageway between the carrier aperture and 
the cartridge storage space so that when the cartridge carrier of the 
instrument is inserted through the aperture, it can pass through the 
channel until it enters the cartridge storage space for the loading of the 
cartridge onto the carrier. The channel is bounded by a base support ledge 
146 extending from the base, and a cover support rib 147 extending from 
the top cover in a mutually opposed relationship to the base support 
ledge. A sloped inlet ramp 148 is also provided to further facilitate the 
insertion and withdrawal of the cartridge carrier of the instrument. The 
sloped inlet ramp extends from the carrier aperture to the carrier 
channel. 
The base 132 of the cartridge casing contains a pad 149 upon which the 
suture filament of the suture cartridge is placed. The top cover has a 
suture retainer 150 for retaining the suture filament of the suture 
cartridge in a fixed position on the pad when the top cover is secured 
onto the base. In a similar fashion, the top cover has a needle retainer 
151 for retaining the surgical needle attached to the suture filament of 
the suture cartridge on the pad when the top cover is placed on the base 
of the cartridge casing. 
The cartridge storage space 140 within the cartridge casing of load assist 
device receives a suture cartridge 152. The suture cartridge contains a 
surgical filament 153 configured into a partially tied knot with a first 
loop 154, and a surgical needle 155 attached to a distal end of the 
surgical filament. The suture cartridge has a cartridge top 156, and a jaw 
157 facing the cartridge top. The jaw is pivotally movable at a pivot pin 
158 from an open position spaced from the cartridge top to a closed 
position adjacent the cartridge top. The jaw is normally biased in its 
open position. 
The first loop 154 and the surgical filament 153 are held within the 
assembly as depicted in FIG. 42 on the central plane offset midway between 
the external faces of the base 132 and cover 133. So constrained, the loop 
154 and filament 153 do not become tangled or pinched during the loading 
of the suture cartridge 152 into the cartridge carrier. 
The preferred suture cartridge in the practice of this invention is the 
assembly depicted in FIGS. 24-39. The suture cartridge 152 is situated in 
the cartridge storage space so that a proximal end of the suture cartridge 
sits on the proximal retainer 141. A distal end of the suture cartridge 
sits on the distal retainer 142, and the jaw 157 is retained against the 
jaw retaining ledge 143. In order to firmly secure the suture cartridge in 
the cartridge storage space, the spacing between the distal retainer and 
the jaw retaining ledge is such that the jaw is oriented in a position 
between its open and closed positions. In this manner, the biasing action 
of the jaw against the jaw retaining ledge helps to firmly plant the 
suture cartridge within the cartridge storage space. It is also noteworthy 
that the suture cartridge within the cartridge storage space is sloped 
downwardly from the cartridge proximal end to the cartridge distal end. 
The assembly depicted in FIG. 42 may be packaged and sterilized using 
conventional techniques such as gamma irradiation or ethylene oxide 
exposure. 
A surgical instrument 159 is used in cooperation with the load assist 
device for loading the suture cartridge from the cartridge casing onto the 
instrument for subsequent deployment of a knot from the suture filament 
contained in the suture cartridge. The surgical instrument can be a 
conventional open instrument or an endoscopic instrument adapted for 
minimally invasive surgery. Preferably, the instrument is an endoscopic 
surgical instrument. Advantageously, it has a cartridge carrier 160 
configured for insertion and withdrawal into and out of the carrier 
aperture of the cartridge casing, and passage through the carrier channel 
to the cartridge storage space. Of course, it must also be configured to 
receive the suture cartridge from the cartridge storage space. Preferably, 
the surgical instrument has a closure tube 161 movable from a retracted 
position to an extended position for opening and closing the jaw relative 
to the cartridge top of the suture cartridge. 
Referring now to FIGS. 43-49, there is shown the sequence of steps for 
loading the cartridge carrier of the surgical instrument with the suture 
cartridge encased in the cartridge storage space of the cartridge casing 
of the load assist device. In FIG. 43, the cartridge carrier is oriented 
for insertion into the carrier aperture and passage through the carrier 
channel. In FIG. 44, the cartridge carrier has been inserted into the 
carrier aperture, and is passed through the carrier channel in a loading 
direction indicated by the arrow until it has made contact with the suture 
cartridge within the cartridge storage space of the cartridge casing. As a 
result of the sloped orientation of the suture cartridge, the cartridge 
carrier contacts the suture cartridge at a point intermediate between the 
proximal and distal ends of the suture cartridge. Referring now to FIG. 
45, the carrier is moved distally in the cartridge storage space, causing 
the suture cartridge to be dislodged from the distal and proximal 
retainers in the cartridge storage space. The dislodgment of the suture 
cartridge from the distal and proximal retainers, in combination with the 
movement of the cartridge carrier distally within the cartridge storage 
space, causes the suture cartridge to be received in the cartridge carrier 
of the instrument. As the suture cartridge is loaded into the cartridge 
carrier when the cartridge carrier is moved distally, the closure tube of 
the surgical instrument is maintained in its retracted position. It is 
also noteworthy that because of the slight pressure exerted on the suture 
filament and surgical needle sitting on the pad from the suture and needle 
retainers of the top cover, there is no interfering movement of the suture 
filament and needle during loading operation. In FIG. 46, once the 
cartridge carrier of the instrument is loaded with the suture cartridge, 
the closure tube of the instrument is moved from its retracted position to 
its forward position, thus securing the suture cartridge in the cartridge 
carrier of the instrument. 
Observing specifically FIGS. 47-49, the loaded cartridge carrier of the 
instrument is removed from the cartridge casing of the load assist device. 
It is removed simply by withdrawing the cartridge carrier from the 
cartridge storage space, carrier channel and carrier aperture of the 
cartridge casing in an unloading direction as indicated by the arrow in 
FIG. 47. 
Advantageously, there is a small gap between the base ledge 146 and cover 
support rib 147 bounding the interior carrier channel within the cartridge 
casing so that the suture filament and surgical needle can freely pass out 
of the cartridge casing (See FIG. 41 to see the gap). Likewise, the 
pressure which the suture and needle retainers exert on the suture 
filament and needle sitting on the pad within the base of the cartridge 
casing is minimal so that the filament and needle can readily pass out of 
the cartridge casing. 
Once the surgical instrument is used to deploy a knot from the suture 
filament contained in the surgical cartridge which has been loaded into 
the cartridge carrier of the instrument, the surgeon or operating room 
assistant can unload the spent cartridge and dispose of it. If additional 
surgical knots need to be deployed, the surgeon or operating room 
assistant need only procure another load assist device of this invention 
to facilitate the loading of a second suture cartridge onto the cartridge 
carrier of the instrument. 
The different embodiments of this invention are representative of the 
preferred embodiments of the invention. These embodiments are merely 
illustrative. The scope of the invention should not be construed to be 
limited by these embodiments, or any other particular embodiments which 
may come to mind to those skilled in this art. Instead, the reader must 
refer to the claims which appear below to determine the scope of the 
invention.