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Description  |
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The invention relates to a method and apparatus for removing liquids,
tissue or the like from the interior of a body, such as a living organism,
with an elongated hollow body, such as a hose or a cannula and with a
suction device.
For example biopsy instrument sets with a cannula as the hollow body are
knwon, which at the end to be inserted in the body is ground in an
appropriate manner and, at least during insertion or piercing, a mandrin
is provided in the cannula. The mandrin can be pointed in stiletto-like
manner at its front distal end and is also referred to as a stiletto. At
its rear, proximal end, it can have a handle. When the distal end has come
into the area where the tissue sample is to be taken, the mandrin is at
least partly or even completely drawn out of the cannula and a tissue
sample is removed for histological and/or cytological examination by
further piercing or pressureless cutting, a medical syringe being fixed
for additional suction of the bioptate after inserting the steel needle
and subsequently removing the mandrin. The syringe is then drawn up, the
complete arrangement rotated in order to cut out a cylinder of material
and finally the arrangement is drawn out of the body. The cylinder of
material is ejected from the cannula by pressing down the syringe. The
procedure described for removal purposes can easily lead to a displacement
of the cannula, which can lead to misrouting with complications and can
also cause pain. Until the medical syringe is drawn up, the end, which
e.g. in the case of pneumocentesis is inserted in the lung, is
disadvantageously linked with the outside air. This biopsy instrument set
does not permit the removal of tissue fluid. For this purpose it is
necessary to provide another biopsy instrument set in which the cannula is
fixed to the cylinder of a medical syringe and a hollow stiletto guided in
the cannula is fixed to the syringe plunger so that, on drawing up the
syringe, tissue fluid is sucked through the resulting vacuum into the
syringe cylinder. This syringe suffers from the disadvantage that, due to
the considerable volume produced in the cylinder by the suction, it is
necessary to remove a relatively large amount of tissue fluid and this can
lead to the traumatization of the examined tissue. However, due to the
relatively large initial volume, prior to suction and at the start of
suction, there can be a relatively weak vacuum, which can be
disadvantageous. The latter applies with respect to the sucking of liquid
from wounds, effusions, body cavities or the like by means of hoses, such
as catheter hoses and medical syringes.
An object of the present invention is to develop an improved apparatus of
the aforementioned type that by means thereof and in a clearly defined,
careful manner, it is possible to provide a method or removing tissue or
fluid in a simple and in particular easily manageable manner, in such a
way that removal takes place efficiently and requires less time, while
being less of a strain for the patient. In addition, through a smaller
number of manipulations, the traumatization risk is reduced and the
accuracy at removal points improved.
According to the invention, the above object is achieved by an apparatus of
the present type in that in the hollow body is guided an elongated
obturator substantially adapted to the cavity thereof and a seal is
arranged in an area of the hollow body remote from the insertion end.
Tissue samples for histological examination, tissue fluid for cytological
examination and other fluids are drawn up and received with a high suction
power in the case of the apparatus used according to the invention into
the cavity freed in the hollow body on drawing up the obturator. While the
apparatus according to the invention is particularly intended for biopsies
on living organisms, it can also be used for postmortem biopsies and for
taking samples from any appropriate dead material, as well as for material
testing purposes. The procedure required according to the invention is
much simpler. After inserting the elongated hollow body with the obturator
inserted therein into the body, the obturator is drawn up and, optionally,
completely removed. In the latter case the seal is constructed in
self-sealing manner, so that following the removal of the obturator it
provides a complete seal and consequently the vacuum in the hollow body is
maintained. Thus, any fluid drawn up is maintained in the hollow body and
can be removed therewith from the body. In the case of puncturing for
tissue removal purposes by means of a cannula with an introduced mandrin,
the latter is drawn up and, optionally, completely removed, so that once
again the vacuum produced is maintained. The cannula merely needs to be
inserted over the length of the desired tissue plug and turning for
cutting is not longer necessary, the cutting being brought about during
the easy insertion as a result of vacuum action. On pulling the cannula
out of the body, the tissue sample is ejected from the cannula by again
inserting the mandrin. It is much easier to keep the tissue samples, no
matter what their consistency, e.g. whether they are lung, kidney or liver
tissues. This results from the fact that when removing a tissue sample on
cutting or piercing the tissue plug from the tissue area to be examined,
the taking up of the tissue is aided by the vacuum in the cannula and the
tissue plug cut from the tissue is sucked into the cannula, so that there
is no compression thereof. A disadvantageous traumatization of the
bioptate is obviated, because the cut-out cylinder of tissue cannot shoot
into a syringe. Due to the fact that the seal is located at a distance
from the cannula end introduced into the body and preferably in the
vicinity of the remote end, but in the interior thereof and optionally in
the interior of a widened attachment or the like, the advantage is
obtained that after withdrawing the mandrin and also when removing tissue
fluid, a clearly defined quantity thereof can be sucked into the freed
area of the cannula at a higher vacuum than in the prior art and is then
flexibly absorbed upstream of the seal by the air cushion resulting from
the residualforce prior to the drawing up of the obturator. This clearly
defined small quantity, but which is adequate for examination purposes,
does not lead to excessive traumatization of the tissue removed. Thus,
when the cannula according to the invention is used, it causes less stress
for the patient. As a result of the inventive construction, the
performance and yield of the autopsy (namely a longer intact tissue
cylinder) are improved as a result of the easy handling thereof. It has
surprisingly been found that the inventive apparatus has a much higher
suction pressure at the distal end of the hollow body than when using
conventional medical syringes for producing the vacuum. This is doubtless
due to the fact that as a result of the normally tightly fitting obturator
in the hollow body (the obturator and the hollow body being matched to one
another with limited tolerances), the ratio of the residual volume
containing residual air prior to drawing up the obturator to the suction
volume obtained on drawing up the obturator is very small, or the
reciprocal value is high.
As a result of the seal no material can be sucked, because even after
removing the mandrin, the hollow channel can be closed again. Unlike in
the prior art, a medical syringe is no longer necessary. A better aiming
precision and greater sensitivity is obtained, e.g. on insertion, but also
when turning the cannula for turning cutting purposes. In particular, all
manner of cutting operations at the distal end of the cannula can be
combined with the construction according to the invention.
According to a preferred embodiment, the seal is made from rubber, silicone
or some other material. The seal is preferably inserted as a completely
closed sealing disk in the interior of the hollow body and is then pierced
by the mandrin, so that the seal completely surrounds the latter in a
reliable sealing manner. The seal necessarily remains tight on partial
drawing out or removal of the obturator. If the obturator or mandrin is to
be completely removed, the sealing disk remains completely tight due to
self-sealing when the mandrin is completely removed and therefore seals
the needle cavity again in a complete manner and consequently maintains
the vacuum causing the suction action in the hollow body. According to a
preferred embodiment, the hollow body has a widened cavity, e.g. in the
interior of an adapter, such as a Luer adapter and the seal is formed in
the widened cavity. With such a construction it is easier to insert the
seal. This leads to the further advantage that the larger the diameter of
the seal is than the mandrin pierced through it, more sealing compound is
available, so as to again achieve a reliable seal on completely removing
the mandrin. Advantageously, the seal is secured by a retaining ring or by
bonding. Apart from the aforementioned advantages on inserting and using
the cannula according to the invention, the fact that no medical syringe
has to be used for drawing up the mandrin or stiletto and should not be
used for the optimum utilization of all the advantages of the invention,
results in the further advantage of material saving and, therefore, lower
price. The inventive apparatus can, in particular, be used with an
endoscope and can, if necessary, be correspondingly constructed. In place
of the rigid bend of the conventional endoscope, the apparatus can have an
angular, adequately flexible and axial, but rigid guide hose for insertion
through the endoscope. The hose is preferably constructed as a metallic
hose with a rigid front, i.e. distal, sharpened end, i.e. formed as a
cannula, whose length, as a function of its diameter, is determined by the
endoscope bend dimensions. The metallic hose can e.g. be formed by a
helical spring or in some other way. If necessary, in order to ensure the
necessary vacuum in the removal region, it is internally provided with a
ring packing at the transition point between the flexible hose and the
rigid cannula. A marking or a stop can be provided at the proximal
actuating end for checking the drawing up length.
Further advantages and features of the invention can be gathered from the
claims and following description relative to a non-limitative embodiment
of the invention and with reference to the drawings, wherein:
FIG. 1 shows a first embodiment of a biopsy instrument set with a preferred
embodiment of the inventive cannula.
FIG. 2 shows a general view of another biopsy instrument set with the
preferred embodiment of the inventive cannula.
FIG. 3 shows a partial representation of FIG. 2 with the plunger withdrawn.
FIG. 4 shows a detail of area III in FIG. 2, completely in section.
FIG. 5a shows a suction tube constructed according to the invention.
FIG. 5b shows a larger-scale detail of FIG. 5a.
The biopsy instrument set 1 shown in FIG. 1 has a cannula 4, which
comprises a metal shank 44 and a grip 16, in which the metal shank 44 is
fixed and joined e.g. by means of a sealing compound 46. Grip 16 is made
from a suitable stable plastic and can, e.g., be constructed in the form
of an adapter, such as a Luer adapter. However, even in the embodiment
shown in FIG. 1 it still has the function of a grip and can be used in the
embodiment shown in FIGS. 2 to 4. The grip 16 could obviously also have a
different configuration from that shown in FIG. 1 and could, e.g., be
provided with radially projecting flanges and the like. The biopsy
instrument set 1 also has a stiletto or mandrin 12, which is guided in
cannula 4. Cannula 4 and mandrin 12 are pointed and sharpened at their end
remote from grip 16 and, e.g., cannula 4 has a trocar ground section,
inner ground section or the like. At its proximal end, mandrin 12 has a
handle 17, which in the same way as grip 16 can be made from stable
plastic and is preferably made from the same plastic, is fixed to the
mandrin by use of e.g., a sealing compound 18. When the mandrin 12 is
fully inserted in cannula 4, the tip of the mandrin 12 projects out of the
cannula end to be introduced into the body. A seal 47 is placed in grip 16
of cannula 4. It rests on the one hand on a shoulder 48 formed on the
interior of grip 16 and is also secured on its side remote from shoulder
14 by an inserted ring 49, which is secured, e.g., by welding to grip 16.
Seal 47 is preferably a disk made from a suitable elastic material, such
as plastic, natural rubber, artificial rubber, e.g., silicone rubber or
the like. On inserting mandrin 12 in cannula 4, the sealing disk 47 is
perforated and then surrounds the mandrin 12 with extremely high
tightness. Even when mandrin 12 is drawn out, the sealing disk seals
itself again in its perforated area, so that it also remains completely
tight.
The biopsy instrument set is used for removing, from body organs, tissue
which is in particular to be examined histologically and the cannula 4
with inserted mandrin 12 (i.e., in the reprsentation according to FIG. 1)
is introduced into the interior of the body, optionally with the aid of a
guide needle, such as a Straus cannula. While firmly holding cannula 4 by
its grip 16, for removal purposes mandrin 12 is drawn up after acting on
its handle 17 and consequently the front cavity of cannula 4 is freed for
receiving tissue, which has already been sucked to a certain extent into
the distal end of cannula 4. In particular, mandrin 12 can be completely
removed, seal 47 then automatically and reliably sealing the inner area of
cannula 4. When taking up tissue and, in particular in the case of a
suitable ground joint of the inserted end of the cannula, the latter is
moved by rotation or pressing on grip 16 and is pressed further in the
area which is of interest, which leads to a screwing movement of cannula 4
and consequently a tissue plug is cut out in bioptate form from the tissue
and is sucked up completely into cannula 4. Cannula 4 with the bioptate is
drawn out of the body and, by means of mandrin 12 which has been
reinserted in cannula 4, the bioptate is removed from the cannula and is
placed, e.g., in formalin for fixing purposes.
In fundamentally the same manner as described relative to FIG. 1, the
biopsy instrument set with the cannula 4 according to the invention can
also be used for withdrawing by suction a clearly defined quantity of
tissue fluid for cytological examination, without any medical syringe
being necessary, although such a syringe can be used, as will be shown
hereinafter. In this case there is no cutting out of tissue parts by the
cannula and with the latter firmly held, tissue fluid is sucked into the
cannula 4 merely by drawing up mandrin 12 by means of handle 17, it being
possible to very accurately determine the quantity by the amount of
drawing. Hereinafter a description is given of another biopsy instrument
set construction with fundamentally the same embodiment of the inventive
cannula and fundamentally identical parts are given the same reference
numerals.
The biopsy instrument set 10 shown in FIGS. 2 to 4 has a medical syringe
with a hollow cylinder 2 to which the cannula 4 is connected at a front
end 3. End 3 of hollow cylinder 2 can have a joining shoulder 41 with an
internal thread 42, to which the cannula 4 can be fixed by means of an
adapter 43, e.g., a Luer adapter and can fundamentally be constructed in
the same way as grip 16 of FIG. 1, but in this case is not used as such. A
plunger 8 is guided in hollow cylinder 2 and is provided at its end facing
cannula 4 with a piston 11 located in the hollow cylinder. A stiletto or
mandrin 12 guided in cannula 4 is joined to the plunger 8. At their ends
6, 13 remote from hollow cylinder 2 or plunger 8, cannula 4 and mandrin 12
are pointed and sharpened, e.g., the cannula 4 with a trocar ground joint,
inner ground joint or the like. With the plunger 8 fully inserted into the
hollow cylinder 2, the tip of the mandrin 12 projects a few millimeters
out of the end 6 of cannula 4. Plunger 8 can either be manually drawn up
in hollow cylinder 2 or can be under the tension of a spring 23 and can
initially be secured by an arresting means 27 connected to hollow cylinder
2 and which can be released by an actuator 34, as shown in FIG. 1.
As stated, cannula 4 has an adapter 43, which is fixed to the metal shank
44 of cannula 4, e.g., by means of a sealing compound 46. As described
relative to FIG. 1, a seal 47 is inserted in adapter 43 of cannula 4. The
seal is constructed and secured in the same way as described relative to
FIG. 1.
This biopsy instrument set is also used for removing, from body organs,
tissue which is to be examined histologically or tissue fluid which is to
be examined cytologically. It is used fundamentally in the manner
described relative to FIG. 1 by gripping on cylinder 2 and plunger 8 or by
drawing up the plunger by releasing a tensioned spring.
FIGS. 5a and 5b, the apparatus 1' according to the invention is shown with
a suction tube 4' and a hollow plastic body 44'. In the manner described
with reference to FIG. 1, the seal can be formed in the cavity of an
adapter at the end remote from the end of the tube to be inserted in the
body. An obturator 12', e.g., also a mandrin having a grip 17' at one end,
is inserted in the hollow body 44'. The end of tube 4' to be inserted in
the body and which is opposite to the insertion opening of obturator 12'
is closed in the represented embodiment, while suction openings are
provided in this area in the side wall. As a function of the intended use,
this could be replaced by having the end wall open. In the represented
embodiment, sealing takes place in the manner represented in detail A in
FIG. 5b, in that the tube wall 44' has an annular thickened portion 45' in
its inner circumference and the cross-section left free by said thickened
portion 45' when mandrin 12' is not inserted has a smaller diameter than
the latter. By inserting the mandrin 12', the thickened portion is forced
outwards, so that a reliable seal is obtained. By appropriate defined
compression, during heat treatment or the like, thickened portion 45' can
be formed from the plastic body 44' of the tube or in any other
appropriate manner.
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