Method and anastomotic instrument for use when performing an end-to-side anastomosis

An anastomotic instrument (201) and a method for establishing an end-to-side anastomosis. The instrument includes an anvil assembly (202A, 203, 203A), having stapling recesses (204), a clamping assembly (205B, 205A) adapted to be advanced towards the rear face of the anvil (203), and a stapling assembly (206, 206A), to be moved towards the anvil (203). All three assemblies can be split along a common dividing surface, and during the operation, the separable parts of the assemblies are held together by a common elastic rubber sheath (410), to ensure a correct sequence of relative movement when the three assemblies are pressed together by a manual implement having jaws (202C, 206C). After the anastomosis has been established, the rubber sheath (410) may be cut open to enable the separable parts to be separated from each other.

TECHNICAL FIELD 
The present invention relates to a method and instrument for connecting an 
end region of a first vessel to the side of a second vessel by carrying 
out an end-to-side anastomosis. 
BACKGROUND ART 
A method closely related to the one referred to above is described in the 
international application WO-A-97/16122. In this previous method, the 
various relatively movable assemblies, viz. the anvil assembly, the 
clamping assembly and the stapling assembly, extended circumferentially 
all the way around the internal space in the instrument accommodating the 
first vessel or graft vessel, for which reason it was necessary when 
removing the instrument from the anastomosis having been established to 
move it along the graft vessel to the latter's free end or to pull the 
graft vessel out of the instrument. 
This means, of course, that the instrument of said application 
WO-A-97/16122 can only be used with totally free graft vessels leaving one 
free end after anastomosis, making it possible to use the instrument for 
establishing anastomoses at both ends of an originally free graft 
vessel--or at the only free end of a closely situated anatomical artery 
(typically, but not exclusively the Internal Mammarian Artery--the 
socalled IMA vessel), such as may be required in coronary surgery. 
U.S. Pat. No. 3,519,187 and U.S. Pat. No. 4,076,162 disclose methods 
comprising the use of instruments for connecting an end region of a first 
vessel to the side of a second vessel by carrying out an end-to-side 
anastomosis, in which the anvil assemblies can be split lengthwise. This 
is not, however, sufficient to overcome the limitation explained above, as 
other active assemblies necessitate having a free end on the graft vessel 
to enable them to be removed. 
DISCLOSURE OF THE INVENTION 
It is the object of the present invention to provide a method of the kind 
referred to above, with which it is possible to use the instrument for 
establishing anastomoses at any free end of a graft vessel, such as may be 
required in coronary surgery, and this object is achieved by proceeding as 
set forth hereinbelow. In this manner, all active parts of the instrument 
may be divided along the internal space accommodating the graft vessel, 
the two parts arising out of this dividing being removable sideways from 
the graft vessel, so that the latter does not necessarily have to have a 
free end. 
The present invention also relates to an anastomotic instrument for 
carrying out the method according to the invention. This instrument is for 
connecting an end region of a first vessel to the side of a second vessel 
by carrying out an end-to-side anastomosis, corresponding to the Prior Art 
as disclosed in the above-mentioned U.S. Pat. No. 3,519,187, and according 
to the invention, it also comprises the features set forth hereafter. 
Advantageous embodiments of the method and the anastomotic instrument 
according to the invention, and the effects of which (beyond what is 
self-evident) are explained in the following detailed part of the present 
description.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As mentioned above, the embodiment shown in FIGS. 1-8 of the anastomosis 
instrument according to the invention subject of the application 
WO-A-97/16122 constitutes a simplified version with the primary purpose of 
explaining the invention; this does not, however, preclude the possibility 
of using this embodiment in actual practice. 
Thus, FIG. 1 shows an anastomosis instrument 1 consisting of three main 
components that are movable relative to each other in the longitudinal 
direction, i.e. in the direction shown as the vertical direction in FIG. 
1: 
an anvil tube 2, 
a clamping tube 5, and 
a set of stapling plungers 6. 
On its lower end, the anvil tube 2 carries an anvil 3, the upper side of 
which is provided with a number of staple-bending recesses 4 adapted to 
cooperate with and bend an equal number of staples 7, in the situation 
shown in FIG. 1 being temporarily held lightly in an equal number of 
staple-holding recesses 8 formed in the lower ends of the stapling 
plungers 6. 
FIG. 2 shows the situation, in which the instrument is made ready for use 
by the operating surgeon. As mentioned initially, the anastomosis 
instrument shown is primarily developed for use when performing coronary 
bypass operations, and to this end, a bypass vessel 9--that may be a vein 
taken from some other part of the patient's body--has been inserted in the 
anvil tube with its lower end everted about the anvil 3 and with its end 
region 10 covering the staple-bending recesses 4 in the upper surface of 
the anvil 3. At this point it should be noted that the bypass vessel 9 may 
have a considerably larger circumference than the inside of the anvil tube 
2, consequently lying more or less folded in the longitudinal direction in 
the latter, for which reason the action of everting its end region 10 
about the anvil 3 does not necessarily entail undue stretching of the 
bypass vessel 9. 
FIG. 3 shows the instrument having been made ready as shown in FIG. 2 
inserted in an opening in a coronary artery 11, said opening having an 
edge region 12 which, due to the elasticity of the tissue of the coronary 
artery 11, will embrace the anvil tube 2 in a location close to the anvil 
3. The opening in the coronary artery 11 may e.g. have been formed 
according to the method described in the international application with 
publication No. WO 95/17127 with the title "Method and instrument for 
establishing the receiving side of a coronary artery bypass graft". 
As soon as the operating surgeon in the situation shown in FIG. 3 has 
ascertained that the edge region 12 embraces the anvil tube 2 closely on 
all sides, he or she will proceed to the situation shown in FIG. 4, in 
which the clamping tube 5 has been moved towards the anvil 3 so as to 
clamp the edge region 12 on the coronary artery 11 and the end region 10 
on the bypass vessel 9 firmly together in readiness for the next step 
shown in FIG. 5, in which the stapling plungers 6 have been moved 
downwardly so as to cause the staples 7 to penetrate the edge region 12 
and the end region 10 and engage the staple-bending recesses 4, by which 
they will be bent in a tangential direction in a similar manner as is 
known from both surgical staplers and ordinary office staplers. 
In the situation shown in FIG. 6, the clamping tube 5 together with the 
stapling plungers 6 have been moved outwardly and away from the staples 7, 
the staple-holding recesses 8 due to their light holding action having let 
go of the staples 7, the latter also having been anchored in the end 
region 10 by their bent ends. 
FIG. 7 shows the situation, in which the operation of removing the 
anastomosis instrument 1 from the coronary artery 11 and its anastomosis 
with the bypass vessel 9 has begun. As will be seen from FIGS. 6 and 7, 
the circumferential pocket formed by the eversion of the lower end of the 
bypass vessel 9 will now open and allow the anvil 3 to be removed by 
luxation, FIG. 8 showing the situation after such removal, resulting in a 
finished anastomosis of the intima-to-intima type considered most 
desirable for this type of operation. 
The three main components of the anastomosis instrument 1 referred to 
above, i.e. the anvil tube 2, the clamping tube 5 and the set of stapling 
plungers 6, will, of course, have to be connected to some kind of 
operating members to enable the operating surgeon and his or her 
assistants to carry out the steps shown in FIGS. 1-8. Theoretically, these 
operating members could consist of three tubes (not shown), viz. 
a relatively long holding tube in continuation of the anvil tube 2, 
a somewhat shorter clamping tube in continuation of the clamping tube 5, 
and 
an even shorter stapling tube, to which the stapling plungers 6 are 
connected. 
As is well-known, however, coronary bypass operations, especially according 
to the method subject to the international application No. WO 95/17127 
entitled "Method and instrument for establishing the receiving site of a 
coronary artery bypass graft", should be carried out as rapidly as 
possible, and for this reason, the "theoretical" embodiment shown in FIGS. 
1-7 is too cumbersome to work with to ensure a sufficiently rapid 
operating procedure. As mentioned above, FIGS. 9-12 illustrate an 
embodiment of an anastomosis instrument, that is highly suitable for 
creating an end-to-side anastomosis in a very short time. 
Due to the construction of the instrument shown in FIGS. 9-12 it is not 
possible to make an easily understandable drawing in the nature of the 
simple drawings of FIGS. 1-7. For this reason, the "active" parts of the 
instrument have been shown in perspective, and with the exception of the 
anvil and its supporting columns, with one half removed along a 
longitudinal sectional plane, so that the remaining half can be seen 
partly from the inside, partly from the outside. In FIGS. 9-12, those of 
the components functionally corresponding to components shown in FIGS. 1-7 
have been given the same reference numbers with 100 added, whereas 
components not having "opposite numbers" in FIGS. 1-7 have been given the 
reference numbers of the components, with which they are most closely 
associated, with the addition of a capital letter. 
As shown in FIG. 9, the anastomosis instrument 101 comprises a number of 
parts functionally corresponding to parts of the instrument shown in FIGS. 
1-7, viz.: 
an anvil tube 102, 
an anvil 103, 
a clamping tube 105, and 
a set of stapling plungers 106. 
Although the basic functions of these parts are the same as the basic 
functions of the corresponding parts in the embodiment of FIGS. 1-7, the 
arrangement differs somewhat from that of the latter, as will be evident 
from the following. 
In contrast to the anvil tube 2 of FIG. 1, the anvil tube 102 of FIG. 9 
extends on the outside of the instrument and is terminated by an end wall 
102A, to which the anvil 103 is secured at a distance by means of two 
columns, viz. an upstream column 103A and a downstream column 103B. The 
expressions "upstream" and "downstream" to the direction of blood flow in 
the artery, in which the instrument 101 will normally, but not necessarily 
exclusively, be used in creating an end-to-side anastomosis. 
To make it possible to insert the bypass vessel (not shown) corresponding 
to the bypass vessel 9 shown in FIGS. 1-8, all transversely oriented 
components have suitable openings, of which the forwardmost opening 103C 
is formed in the anvil 103, the latter being provided with staple-bending 
recesses 104 having the same function as the staple-bending recesses 4 
shown in FIG. 1. 
As will be seen from FIGS. 9-12, the various components are not 
rotationally symmetrical about the longitudinal axis of the instrument, as 
the anvil 103 has been made "boat-shaped" to make it easier to insert it 
in the opening in the artery and to make it easier for the edges of the 
opening to fit in with the upper side of the anvil 103 with the stapling 
recesses 104. 
Due to the arrangement of the anvil tube 102 as the outermost component 
terminated by the end wall 102A, it is not possible in this embodiment to 
let the clamping tube 105 extend in its full circumferential width all the 
way towards the upper face of the anvil 103. For this reason, the clamping 
tube 105 is terminated by an end wall 105A, from which a set of clamping 
columns 105B extend in the forward (downward) direction through suitable 
openings in the anvil tube end wall 102A. 
The stapling plungers 106 are guided in the longitudinal direction in 
suitable guides in the clamping columns 105B, and their rearmost 
(uppermost) ends are secured to a stapling plunger carrier 106A, itself 
secured to and terminating a stapling tube 106B, through which the force 
for actuating the stapling plungers 106 may be transmitted from a suitable 
operating device. FIGS. 9-12 show neither staples corresponding to the 
staples 7 of FIG. nor staple-holding recesses corresponding to the 
staple-holding recesses 8 shown in FIG. 1, but it will be understood that 
the forwardmost (lowermost) ends of the stapling plungers 106 will be 
provided with suitable staple-holding recesses capable of holding staples 
in such a position, that when the stapling plungers 106 are advanced 
towards the anvil 103, the staples will be bent by the staple-bending 
recesses 104 in the usual manner. 
The relative positions of the various parts as shown in FIG. 9 correspond 
to those shown in FIGS. 1-3, i.e. there is a sufficient distance between 
the rearward (upper) face of the anvil 103 and the forward (downward) ends 
of the clamping columns LOSB to accomodate the everted end region of the 
bypass vessel corresponding to the end region 10 shown in FIG. 2, as well 
as the edge region of the coronary artery concerned corresponding to the 
edge region 12 of the coronary artery 11 shown in FIG. 3. 
The situation shown in FIG. 10 corresponds to that shown in FIG. 4, i.e. 
the clamping columns 105B have been advanced towards the anvil 103, in 
FIG. 10 leaving a gap symbolizing the presence of the end region of the 
bypass vessel and the edge region of the coronary artery (all not shown) . 
The movement of the clamping columns 105B has, of course, been effected by 
advancing the clamping tube 105 to the same extent. To prevent said end 
and edge regions being crushed in the clamping operation, suitable stops 
(not shown) are adapted to stop the movement of the clamping columns 105B 
towards the anvil 103 so as to leave a gap just sufficient to hold them 
firmly together. To improve the grip, the clamping surfaces may be 
provided with elastically flexible fins or fingers. FIG. 13 shows how this 
concept could be applied to the embodiment shown in FIGS. 1-7, it 
being--of course--equally applicable to that shown in FIGS. 9-12, or the 
apparatus according to the present invention shown in FIGS. 14-18 and 
described below. 
The relative positions shown in FIG. 11 correspond to those shown in FIG. 
5, i.e. the stapling plungers 106 have now been advanced, guided by the 
clamping columns 105B so as to bring the staples (not shown) into 
engagement with the staple-bending recesses 104, thus joining the end 
region of the bypass vessel to the edge region of the coronary artery (all 
not shown). 
The relative positions shown in FIG. 12 correspond to those shown in FIGS. 
6 and 7 and with the exception that in FIG. 12, the stapling plungers 106 
have not only been withdrawn from the staples joining the two vessels, but 
have in fact been removed completely from the instrument to make it 
possible to insert a new set of staples, that may be of the disposable or 
semi-disposable type. 
With the arrangement shown in FIGS. 9-12, the operating surgeon may 
literally have a firm grip on the situation by holding the outermost 
component, i.e. the anvil tube 102, which is rigidly connected to the 
anvil 103 through the columns 103A and 103B, so that he or she will be 
able to move the anvil 103 with the everted end of the bypass vessel into 
the opening in the coronary artery by direct manual control, and--not 
least--by "direct mechanical feedback", as the rigid mechanical 
interconnection between the anvil 103 og the anvil tube 102 enables the 
surgeon to "feel" whatever object is encountered by the anvil. 
Advantageously, the rearward (upper) part (not shown) of the instrument 
may comprise suitable operating devices and/or mechanisms for moving the 
clamping tube 105 and the stapling plungers 106 relatively to the anvil 
tube 102 and hence relatively to the anvil 103. Due to the extremely 
limited time available for performing coronary bypass operations, these 
operating devices and/or mechanisms should be designed to enable the 
operating surgeon to initiate the requisite movements rapidly and with a 
minimum of effort. 
Thus, the operating devices and/or mechanisms could be arranged to function 
under the control of a single operating member, such as a push-button on 
the rear (upper) end of the instrument adapted to be operated by the 
surgeon's thumb, in the following manner: 
firstly, when the operating member is moved in a first direction, e.g. a 
push-button is depressed, the clamping columns 105B will be advanced to 
their forwardmost (lower) position, in which they clamp the end region of 
the bypass vessel and the edge region of the opening in the artery 
together until said stop is reached, and then the stapling plungers 106 
will immediately be actuated to staple the two regions together, after 
which both the clamping columns 105B and the stapling plungers 106 are 
withdrawn, e.g. by releasing said push-button, and 
secondly, immediately upon the operating member moving in the opposite 
direction, e.g. when the push-button has been released, the mechanism is 
re-set in readiness for a movement in the first direction, after which the 
instrument can be removed as described above with reference to FIG. 7. 
The anastomotic instrument according to the present invention shown in 
FIGS. 14-18 possesses several features in commom with that of the previous 
application referred to initially and shown in FIGS. 11-13, especially 
FIGS. 9-12, this being the main reason for including a description of the 
previous embodiments in order to make it easier to understand the 
functioning of the instrument according to the present invention. 
Looking at FIG. 14, showing some of the essential parts of the instrument, 
it will be seen that the instrument comprises a number of components with 
the same functions as those of the instrument shown in FIGS. 9-12. At this 
stage it should be noted that the instrument is adapted to be split along 
a longitudinal dividing plane, and FIG. 14 shows solely the parts on one 
side of this plane. 
The reference numerals of the parts shown in FIGS. 14-18 are mostly the 
same as those of parts having similar functions down in FIGS. 9-12 with 
100 or 200 added. 
Thus, the parts shown in FIGS. 14-18 of the anastomotic instrument 201 of 
the present invention comprise a first rigid assembly or anvil assembly 
having 
an anvil carrier upstream half 202A, in operation being releasably 
connected to a similar anvil carrier downstream half 302A shown in FIG. 15 
by means of two connecting knobs 202D engaging in suitable recesses (not 
visible) in said downstream half 302A, 
a lower jaw 202c of the instrument 201, the latter being shaped like a pair 
of tongs (vide FIG. 15), and 
an anvil upstream half 203 rigidly connected to the anvil carrier upstream 
half 202A through an anvil upstream column 203A and having two 
staple-bending recesses 204 as well as two connecting knobs 203D for 
releasable connection to an anvil downstream half 303 shown in FIG. 15. 
This first rigid assembly generally corresponds to the assembly shown in 
FIGS. 9-12 comprising 
the anvil tube 102 with its end wall 102A and 
the anvil 103 with staple-bending recesses 104 and connected to said end 
wall 102A through two anvil columns 103A and 103B. 
A second rigid assembly or clamping assembly, movable relative to said 
first rigid assembly, comprises 
a clamping column carrier consisting of an upstream half 205A and a 
downstream half 305A, releasably interconnected by means of connecting 
knobs 205D on said upstream half cooperating with recesses (not visible) 
in the downstream half, rigidly connected to the uppermost end of 
four upstream and downstream clamping columns 205B and 305B respectively, 
slidable in and extending through the respective anvil carrier halves 202A 
and 302A so as to be capable of being moved into abutment with the upper 
side of the anvil upstream and downstream halves 203 and 303 respectively 
in the same manner as shown in FIGS. 4 and 10 depicting the earlier 
instrument. 
This second rigid assembly will be seen generally to to the assembly shown 
in FIGS. 9-12 comprising 
the clamping tube end wall 105A and 
the clamping columns 105B. 
A third rigid assembly or stapling assembly, movable relative to said first 
(anvil) and second (clamping) rigid assemblies, comprises 
a stapling plunger carrier consisting of an upstream half 206A and a 
downstream half 306A, releasably interconnected by means of connecting 
knobs 206D on said upstream half cooperating with recesses (not visible) 
in the downstream half, rigidly connected to the uppermost ends of 
four upstream and downstream stapling plungers 206 and 306 respectively, 
slidable in guideways in the upstream and downstream clamping columns 205B 
and 305B respectively, thus extending through both the clamping carrier 
halves 205A and 305A and the anvil carrier halves 202A and 302A 
respectively, so as to make it possible to advance the stapling plungers 
206 and 306 carrying staples (not shown) in their lowermost ends into 
cooperation with the staple-bending recesses 204 and 304 in the upper 
sides of the anvil halves 203 and 303 respectively in the same manner as 
shown in FIGS. 5 and 11 depicting the earlier instrument. 
This third rigid assembly will be seen generally to correspond to the 
assembly shown in FIGS. 9-12 comprising 
the stapling plunger carrier 106A, and 
the stapling plungers 106. 
After having read the explanation of the functioning of the examples shown 
in FIGS. 1-8 and 9-12 respectively, the reader should turn the attention 
to FIG. 15. 
As will be evident from said explanation, the relative movements between 
the anvil assembly, the clamping assembly and the stapling assembly should 
take place in a certain sequence, i.e. 
I moving the clamping assembly relative to the anvil assembly so as to make 
the clamping columns 205B and 305B clamp the tissue regions 10 and 12 (cf. 
FIG. 4) together, 
II moving the stapling assembly relative to the anvil assembly so as to 
staple the tissue regions 10 and 12 to each other (cf. FIG. 5), and 
III moving the clamping assembly and the stapling assembly together in the 
opposite directions relative to the anvil assembly so as to make it 
possible to liberate the instrument from the anastomosis having been 
established (cf. FIGS. 6-8). 
A preferred feature of the present invention is the use of elastic means 
having different spring characteristics to effect these relative 
movements. The reader is asked to imagine two compression springs or sets 
of same, the first of which is placed between the clamping column carrier 
205A, 305A and the anvil column carrier 202A, 302A and is relatively soft, 
i.e. needs relatively little force to be compressed, the second being 
placed between the stapling plunger carrier 206A, 306A and the clamping 
column carrier 205A, 305A and is relatively stiff. 
Now, slowly squeezing the three assemblies between the lower jaw 202C and 
the upper jaw 206C will first compress relatively soft first spring 
between the clamping column carrier 205A, 305A and the anvil column 
carrier 202A, 302A, thus effecting the relative movement I above, i.e. the 
clamping movement (cf. FIG. 4) 
When the clamping columns 205B and 305B have arrived at their clamping 
position, they cannot be moved further, and continued squeezing will cause 
compression of the second spring or set of springs between the stapling 
plunger carrier 206A, 306A and both the clamping and anvil assemblies, so 
that the stapling plungers will be moved according to the relative 
movement II above (cf. FIG. 5), thus completing the stapling operation and 
creating the anastomosis. 
Finally, relaxing the grip will allow the springs to return the parts to 
the initial relative positions shown in FIG. 15 (cf. also FIGS. 6-8), so 
that the instrument may be removed in a manner corresponding to that shown 
in FIGS. 7 and 8. 
The purpose of dividing the three assemblies in upstream and downstream 
halves is to make it possible 
firstly, with the upstream and downstream halves unified as shown in FIG. 
15, to fit the instrument with a graft vessel (not shown) in a manner like 
that shown in FIG. 2, 
secondly, to establish the anastomosis in a manner like that shown in FIGS. 
3-8, and 
thirdly, according to the present invention, to split the three assemblies 
lengthwise, so as to make it possible to remove the instrument from a 
graft vessel that--typically because it has already been anastomotized or 
has an anatomically fixed origin at the opposite end--cannot be pulled out 
of the assemblies (cf. FIGS. 7 and 8). 
For the above purpose, the present invention preferably specifies the use 
of the elastic member 410 shown in FIGS. 16-18, best understood by also 
looking at FIGS. 14 and 15. This elastic member 410 serves three 
functions, viz.: 
a) keeping the upstream and downstream halves of the three rigid assemblies 
together during the steps of fitting the instrument with a graft vessel 
and establishing the anastomosis, 
b) providing the different spring characteristics necessary for the various 
relative movements to take place in the correct sequence as explained 
above, and 
c) making it possible, in a manner to be explained, to separate the 
upstream and downstream parts from each other to enable them to be removed 
sideways from the graft vessel. 
Thus, the embodiment of the elastic member 410 shown in FIGS. 16-18 
constitutes a sheath of rubber or rubber-like material (in the following 
referred to as "rubber") embracing closely and in elastic tension 
the two anvil carrier halves 202A and 302A, 
the two clamping column carrier halves 205A and 305A, and 
the two stapling plunger carrier halves 206A and 306A, for this purpose 
having internal gripping grooves 411, 412 and 413 respectively cooperating 
with gripping flanges 202G, 302G, 205G, 305G, 206G and 306G respectively. 
Thus, when properly assembled, the three relatively movable assemblies, 
i.e. the anvil assembly, the clamping assembly and the stapling assembly 
described above, together with the rubber sheath 410, present themselves 
as a unified solid body with the external appearance shown in FIG. 17. 
Thus, the rubber sheath 410 can serve function a mentioned above. 
As will be evident from FIGS. 15 and 18, the rubber sheath 410 comprises 
two axially springy segments with different spring characteristics, viz.: 
a relatively soft segment 414 between the gripping grooves 411 and 412 for 
the anvil carrier 202A, 302A and the clamping column carrier 205A, 305A 
respectively, and 
a relatively stiff segment 415 between said gripping groove 412 and the 
gripping groove 413 for the stapling plunger carrier 206A, 306A. 
Thus, the rubber sheath 410 can also serve function b referred to above in 
the manner explained further above using imaginary springs as an example. 
When the anastomosis has been established and the instrument is to be 
removed, the rubber sheath 410 is cut open lengthwise by means of a 
suitable cutting instrument capable of making a cut all the way through 
the sheath 410. Such a cutting instrument could be or comprise a knife 
with indents in the cutting edge for the three gripping flanges 202G, 205G 
and 206G and/or 302G, 305G and 306G. It is, however, preferred to use one 
or two cutting wires (not shown) placed on the internal surface of the 
sheath 410 and having pulling loops or the like (likewise not shown), 
making it possible to cut the sheath 410 open in a manner known from 
various types of sealed packages. 
Thus, function c referred to above can also be achieved by using the rubber 
sheath 410 according to the present invention.