Surgery – Diagnostic testing – Sampling nonliquid body material
Reexamination Certificate
2000-10-03
2003-02-04
Hindenburg, Max (Department: 3736)
Surgery
Diagnostic testing
Sampling nonliquid body material
Reexamination Certificate
active
06514215
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an endoscopic tissue collecting instrument suitable for use typically in a biopsy of the liver, the pancreas or other organ by being inserted into and removed from a treatment instrument insertion channel in an endoscope.
FIG. 31
shows the distal end portion of a Menghini needle used as an endoscopic tissue collecting instrument. It comprises a rod-shaped needle shaft
10
having a pointed end
11
and a tissue retaining recess
12
formed in the lateral side of an area close to the needle end
11
and into which an excised tissue specimen is retained.
A cannula or outer sheath
20
is fitted over the needle shaft
10
to be capable of moving back and forth along the longitudinal axis and it has an annular blade
21
formed on the inner circumference of the tip for cutting off the tissue retained in the recess
12
.
FIGS. 32 and 33
show how a tissue specimen for biopsy is collected with the endoscopic tissue collecting instrument. First, as shown in
FIG. 32
, the outer sheath
20
pierced into the tissue
100
is pulled back a little so that the desired portion of the tissue
100
is caught in the recess
12
. Then, as shown in
FIG. 33
, the outer sheath
20
is immediately pushed forward to cut off the retained portion as a tissue specimen
101
.
A problem with the above-described endoscopic tissue collecting instrument is that the depth of the tissue retaining recess
12
is inevitably much smaller than the diameter of the outer sheath
20
, often causing a failure to collect an adequate amount of the tissue specimen as shown in
FIG. 34
That is, as shown in
FIG. 34
, not all of the recess
12
is filled up with the tissue specimen
101
but some part of it remains empty as shown in
FIG. 34
, and thus the collected tissue specimen
101
is small in amount. Further, as shown
FIG. 35
, when the outer sheath
20
is being pushed forward, the tissue specimen
101
is pushed aside by the outer sheath
20
to be lifted away from the recess
12
. This also causes the volume of the tissue specimen
101
that can be collected in the recess
12
to be much smaller than the capacity of the recess
12
.
An object, therefore, of the present invention is to provide an endoscopic tissue collecting instrument with which an adequate amount of the tissue specimen can be easily collected without increasing the size of the instrument (for example, the diameter of the outer sheath).
The Menghini tissue collecting needle as described above is made up of a simple combination of the needle shaft
10
and the outer sheath
20
, and designed for use together with a rigid endoscope.
Another problem occurs if a rigid endoscope is replaced by a soft endoscope having a flexible part to be inserted into a body cavity. Since the treatment instrument insertion channel of a soft endoscope becomes tortuous as it is passed into a body cavity, a considerably high frictional resistance in the channel makes it difficult to manipulate the needle shaft
10
and the outer sheath
20
such that they are moved back and forth in small increments and independently of each other. Hence, it has been impossible to collect the desired tissue specimen in a safe and quick manner.
Another object, therefore, of the present invention is to provide an endoscopic tissue collecting instrument that is suitable for use with both a rigid and a soft endoscope and which yet can collect the desired tissue specimen in a safe and quick manner.
SUMMARY OF THE INVENTION
According to the present invention, an aspiration channel communicating with a tissue retaining recess from the rear side is formed. The aspiration channel preferably extends between the needle shaft and the outer sheath. Therefore, a large tissue specimen can be collected by aspirating it to be retained in the recess and cutting the aspirated specimen off from the other part of the tissue. In this way, an adequate amount of the tissue specimen can be easily collected without increasing the size of the instrument.
As a further advantage, since the entire length of the aspiration channel is exposed on the surface of the needle shaft, not only the formation of the aspiration channel but also the cleaning and disinfection of it after service can be accomplished with relative ease.
In a preferred embodiment, an endoscopic tissue collecting instrument comprises a needle shaft with a tip pointed forward that has a tissue retaining recess formed in the lateral side of an area close to the tip, and an outer sheath that is fitted over the needle shaft to be capable of moving back and forth and which has a blade formed at the distal end to cut off the tissue retained in the recess. An aspiration channel communicating with the recess from the rear side is formed between the needle shaft and the outer sheath.
The aspiration channel may be formed by removing or denting part of the surface of the needle shaft. This can be accomplished by cutting or denting the shaft's surface to a flat plane, making a groove in the surface or forming a hollow in the form of an inverted &OHgr;.
Preferably, a fixing mechanism is provided to ensure that the outer sheath is fixed to the needle shaft with the needle shaft projecting by a desired length from the distal end of the outer sheath. It is also preferred that an index is provided on the side closer to the operator to tell the operator that the distal end of the outer sheath is in a specified position relative to the needle shaft.
According to the present invention, an outer needle tube, an inner needle tube and an aspirating port are provided. The tissue aspirated into the outer needle tube via the tissue aspirating port formed in its lateral side can be used as a specimen for biopsy. The collected tissue specimen has the largest size that can be expected from the given diameter of the outer needle tube. Hence, an adequate amount of the tissue specimen can be easily collected without increasing the diameter of the outer needle tube.
In addition, since the tissue specimen can be cut off by simply sliding the inner needle tube within the outer needle tube, only small sliding resistance develops and the cutting operation can be done efficiently.
In a preferred embodiment, an endoscopic tissue collecting instrument comprises an outer needle tube with a tip pointed forward that has a tissue aspirating port formed as an opening in the lateral side of an area close to the tip, an inner needle tube that is passed through the outer needle tube to be capable of moving back and forth and which has a blade formed at the distal end to cut off the tissue that has entered the tissue aspirating port, and an aspiration channel that communicates with the tissue aspirating port at the distal end and which extends to the basal ends of the outer and inner needle tubes.
If desired, the aspiration channel may be formed of the inner needle tube per se. The tissue aspirating port may be a cutout formed in the lateral side of the outer needle tube. The blade may be an annular one that is formed on the outer circumference of the inner needle tube.
The endoscopic tissue collecting instrument may be furnished with a guide tube through which the outer needle tube is passed to be capable of moving back and forth along the longitudinal axis.
According to the present invention, the basal end portion of a needle shaft is in engagement with the basal end portion of an outer sheath and a fixing member is provided that can be securely connected to or disconnected from the entrance of a treatment instrument insertion channel in an endoscope. Because of this design, the tissue specimen can be cut off by moving the outer sheath while the needle shaft that has been pierced into the tissue is securely connected to an endoscope. As a result, even in the case where the endoscopic tissue collecting instrument of the invention is passed into a tortuous treatment instrument insertion channel in a soft endoscope, the needle shaft and the outer sheath can be manipulated to move back and forth in small increments and independent
Greenblum & Bernstein P.L.C.
Hindenburg Max
Pentax Corporation
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