JPH11313894A - Stent guide arrangement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widely enhance the possibility or functional effect when a medical doctor operates an end of a probe in a tissue in a body of a patient or the like by providing a probe with a specified number or more of transmission lines extending to the direction of a basic end of the probe from a field transducer. SOLUTION: A field transducer or position sensor is mounted in the vicinity of an end of a probe body. Further, there is provided a set of outer field transducers or antennas 54 for defining a positioning reference coordinates space. For example, the transducer 54 can be installed in a patient's bed. The antenna 54 is connected to a field transmission and reception device 56 and a computer 58. The computer 58 is connected to an input device such as a mouse, track ball, keypad, or a display such as a cathode-ray tube 60.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to the placement of stents in body tract tissue, such as venous or arterial vessels, respiratory tract airways, and intestinal tracts.

[0002]

BACKGROUND OF THE INVENTION As referred to in this disclosure, a stent is a structure that is placed within a body's tubular tissue to reinforce or line the tubular tissue. For example, a stent may be placed in an artery after angioplasty to maintain the patency of the artery or to reinforce the arterial wall, for example, if there is an aneurysm.
The stent is also placed in the esophagus or airway to keep the airway or esophagus open in the presence of a tumor or other abnormal growth. Stents can be placed in the body using an elongated probe such as a catheter or endoscope. The stent is held at the tip of the probe. The stent is usually held on the probe by a holding device such as a balloon that can be manipulated from the proximal end of the probe. The physician first advances the probe tip into the tubular tissue until the tip of the probe is in place in the tubular tissue. Once the tip of the probe is in place, the physician operates the holding device to remove the stent. For example, in the case of a balloon actuated stent, the physician expands the balloon momentarily to expand the stent and engage the tubular tissue, and then contracts the balloon to release the stent from the probe.

[0003] This type of technique has been implemented using fluoroscopic images and other images obtained during this procedure. Fluoroscopic imaging exposes both the patient and the physician to radiation. Furthermore, many internal tubular tissues, such as arteries, are not easily visible using fluoroscopic imaging without the use of contrast media (or contrast agents). These add to the complexity of the procedure and may pose additional risks to the patient. If the procedure is performed using X-ray tomographic imaging (generally referred to as "CT" or "CAT") or magnetic resonance imaging (MRI) during this procedure, all of the steps required to perform the procedure are performed. The device is occupied over time. The need for such equipment during this procedure
Increase the cost of the procedure and limit where it can be performed. Other techniques for placing the stent have been guided by visual observation of the affected area using the optics of the endoscope used to place the stent. These techniques are most used in relatively large organizations.

Certain stents have been developed to reinforce tubular tissue having bifurcated elements, such as, for example, a Y-intersection of the arteries or a Y-intersection of the trachea and the main bronchus. These stents include a first stiffening element having one longitudinal axis and one or more bifurcated or second stiffening elements having a plurality of longitudinal axes transverse to the longitudinal axis of the first stiffening element. For example, when reinforcing a generally Y-shaped cross-section of bifurcated artery tissue, the stent used is also generally Y-shaped. The method of positioning a bifurcated stent poses additional problems that are different from a normal stent. That is, when deploying a typical stent having only a single tubular structure with uniform properties about its longitudinal axis, there is a need to control the direction of the stent rolling or rotating around its longitudinal axis. Absent. Although the longitudinal axis of the stent must be reasonably well aligned with the longitudinal axis of the tubular tissue, this alignment is usually maintained by the mechanical engagement of the stent or probe in the tubular tissue itself. However, when a bifurcated stent is mounted in bifurcated tissue, the orientation of the bifurcated stent must be aligned with that bifurcated tissue. For example, when attaching a generally Y-shaped stent to a generally Y-shaped bifurcation, the orientation of the stent is adjusted so that the bifurcation is oriented in the correct direction and fits within the bifurcation of an artery, airway, or other tubular tissue. I have to adjust. Accordingly, many approaches to deploying such stents require careful passage of a guidewire through the bifurcation tissue to guide the placement of the shunt. Other types of stents also require orientation adjustments.

[0005] Other medical approaches have been implemented using position monitoring devices in which magnetic or electromagnetic or other non-ionic fields are transmitted to or from the probe. For example, U.S. Patent Nos. 5,558,091 and 5,39, incorporated herein by reference.
No. 1,199, No. 5,443,489 and PCT
In the disclosure of WO 96/05768,
The location and / or orientation of the probe tip used in procedures such as surgery or cardiac monitoring or cardiac ablation techniques are primarily based on Hall effect devices or magnetoresistance at or near the probe tip. It can be determined by using one or more field transducers, such as a device, a coil supported on a probe, or other antenna. Still further, one or more additional field transducers are located outside the body in the external reference coordinate space. The field transducer is preferably configured to detect or transmit non-ionizing fields or field components, such as magnetic energy, electromagnetic radiation, or acoustic energy such as ultrasonic vibrations. That is, by transmitting the field between the external field transducer and the field transducer on the probe,
The transmission characteristics of the field between these devices can be determined.
Furthermore, the position and / or orientation of this sensor in the external reference coordinate space can be estimated from these transmission characteristics. Since the position of the probe can be determined by the field transducer of the probe, such a transducer is also referred to as a “position sensor”.

For example, the above-mentioned US Pat. No. 5,558,091
The field transducer in the external reference coordinate space, as described in U.S. Pat.
Since the position and orientation data obtained from the system can be registered as a “me of reference”, the data can be displayed as the outer shape of the probe superimposed on the image of the affected area. The physician can use this information to guide the probe to a desired location within the patient's body and monitor its orientation during treatment or measurement of that body tissue. Therefore, such an arrangement can greatly increase the potential or functional effect of the physician manipulating the tip of the probe within the body tissue. Such a transducer-based system avoids the difficulties associated with manipulating the probe with continuous image processing of the probe and patient during this procedure. For example, the system avoids the inherent exposure to ionic radiation in fluoroscopy.

[0007]

SUMMARY OF THE INVENTION One aspect of the present invention involves a method of applying a stent to tubular tissue in a patient's body. Desirably, the method according to this aspect of the present invention includes the steps of introducing a probe carrying the stent into tubular tissue in the body, and providing at least one field transducer on or from the probe or stent. Transmitting the non-ionic fields to detect each of the fields so transmitted, and at least partially estimating the location of the field transducer from the characteristics of the detected fields. Determining an arrangement. The field transducer on the probe or on the stent passes through the body of the patient, so this field transducer is referred to herein as an "internal" field transducer. Preferably,
The method according to this aspect of the invention further comprises probing the stent if the determining step indicates that the detached stent is to be placed in a preselected tubular tissue region requiring stenting. Removing from the device. As used in this disclosure, the term "disposition" refers to the position, orientation, or both, of an object. The positioning step is performed such that both the location and orientation of the stent are determined, and most preferably the stent is removed from the probe only when the stent is in a predetermined orientation relative to the patient. Typically, tubular tissue has a main vessel, such as an artery, airway, or other element having a longitudinal axis. Preferably, the positioning step is performed such that the direction of rotation of the step about the longitudinal axis of the tubular element is determined. The tubular tissue may be a bifurcated tissue that includes one or more bifurcations intersecting the main vessel.
The stent also has a first reinforcement element adapted to fit within the main tubular tissue and a first reinforcement element adapted to fit within the bifurcation.
One or more second or branch reinforcement elements may be included. In this case, the method adjusts the orientation of the stent based on the placement known in the placement determining step such that the first or main reinforcement element is located in the main vessel, while the branch reinforcement element is located in the bifurcation of the tubular tissue. Preferably, the method further includes a step. For example, if the tubular tissue is a Y-shaped bifurcated tissue and comprises a main tube underlying the Y-tissue and two bifurcations forming the arms of the Y-tissue, the stent comprises a simple Y-shaped tissue. .

[0008] Preferably, determining the position of the stent relative to the patient includes superimposing the stent or probe on an image of the patient. Therefore, the patient image preferably includes an indication of the tubular tissue where the stent is to be placed. Desirably, the step of transmitting one or more non-ionic fields to or from the internal field transducer on the probe or stent comprises positioning each such internal field transducer with a known arrangement relative to each other. Transmitting such a field to and from one or more positioning field transducers defining a reference coordinate space. The placement of the internal field transducer, and thus the placement of the stent, is determined by monitoring the transmitted field. The arrangement in this positioning reference coordinate space is
It can be changed to a common reference coordinate space with patient images. For example, the placement of the stent can be changed to a reference coordinate space of the image, such as a previously obtained MRI, CT, or other image of the patient.

[0009] Another aspect of the present invention is to provide an apparatus for deploying a stent. An apparatus according to aspects of the invention includes an elongated probe having a proximal end and a distal end. The distal end of the probe is adapted to be insertable into the body tubular tissue of a patient. The device further includes a stent removably disposed on the probe near the distal end thereof, and at least one field transducer mounted on the stent or on the probe near the distal end of the probe. The probe also includes one or more transmission paths extending from the field transducer toward a proximal end of the probe. An apparatus according to this aspect of the invention can also be used in a method as described above. Preferably, the stent comprises at least one main reinforcement element and at least one branch reinforcement element, the reinforcement structures of which have axes which intersect each other and are usually inclined to one another. A portion near the probe tip has an extension axis,
The axis of the reinforcement structure is aligned with such an extension axis.

A stent is attached to the probe such that a field transducer is mounted near the tip of the probe and the orientation of the stent remains substantially fixed with respect to the probe while the stent is aligned with the probe. Preferably, it is removably mounted. Thus, the orientation of the stent is in a fixed relationship to the orientation of the field transducer on the probe. Desirably, the probe comprises one or more engagement elements movably mounted near its distal end and an actuator located at or near the proximal end of the probe, the actuator comprising: Is coupled to its engagement element so that the actuator can be moved by the actuator to release the stent from the probe. For example, the engagement element may be a balloon defining an interior space, and the at least one reinforcement element of the stent may be a tubular element surrounding the balloon. Also, the actuator can be a fluid connector, which can be connected to the engagement element or balloon by a tube extending longitudinally along the probe.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus according to one embodiment of the present invention includes a probe 20. Also preferably, probe 20 comprises a catheter having an elongated tubular body 22. The body 22 has a handle or hub 24 fixed to its proximal end and a distal end 26 opposite the handle 24. The body 22 has a bore 28 extending longitudinally from its proximal end to its distal end and handle 24. Further, the main body 22 has a flexible portion in the vicinity of its distal end, and the distal end 26 can be bent or rotated with respect to the rest of the main body. The catheter incorporates a device (not shown) that bends the distal end of its body to steer the device as the catheter is advanced into the body tissue of the patient. The distal end of the catheter body defines a probe body axis 30.

A movable element in the form of a balloon 31 is attached to the distal end 26 of the tail body. The balloon 31 is in the middle inflated position shown by the solid line in FIG. 1, the deflated position 31 'shown by the broken line, and the fully inflated position where the balloon is expanded beyond the partially inflated position (not shown). ). The handle part 24 has a hole 2
A fitting 32 is provided, such as a threaded fitting or a standard Luer taper fitting that leads to 8. The hole 28 communicates with the inside of the balloon 31. Thus, the balloon 31 can move between the inflated position 31 and the deflated 31 ′ by removing fluid from the hole 28 by the fitting 32. The fitting 32 is connected to a pressure control device 34 arranged to move fluid into and out of the hole 28. The pressure control device may be a manually actuated device such as a syringe, sphere or bellows, or other fluid suction and draw device that can be selectively activated.

The stent 36 is a movable element or balloon 3
When the balloon is in an inflated position as shown by a solid line, the balloon is engaged with the tip of the probe and held by the balloon. The stent 36 is a self-expanding device made from a so-called shape memory alloy screen or mesh, such as an alloy sold under NITINOL ™ or other alloys. The stent 36 is preferably at a temperature sufficiently lower than normal body temperature of about 30 ° C. or less, and stably maintains the configuration shown by the solid line in FIG. Since the shape memory alloy changes shape spontaneously when the temperature rises to normal body temperature, ie, about 37 ° C., the stent changes shape spontaneously and assumes an expanded configuration shown by the broken line in FIG. Of course, trade name PALMAZ-SCHAT
Z. Other embodiments, such as balloon expandable or permanently deformable stents, such as the stent marketed by Cordis of Miami Lakes, Florida, the sister company of the assignee of the present invention. It should be understood that stents are also contemplated as being included herein.

The stent includes a main tubular reinforcing element 38 having an axis 40 and a pair of tubular branch elements 42 and 44 having axes 46 and 48, respectively. These branch elements intersect the main tubular element 38 at the tip of the element so that the structure is generally Y-shaped overall. The axis 46 of the bifurcated tubular element, the axis 48 of the bifurcated tubular element, and the axis 40 of the main tubular element are in a plane generally parallel to the plane of the drawing, as can be seen in FIGS.

When the stent is placed on the catheter as shown in FIG. 1, the axis 40 of the main tubular element 38 is aligned with the probe axis 30 defined at the tip of the catheter. Balloon 31 is carried within or on the stent for frictional engagement with the stent. In this state, the stent is firmly held by the movable element or balloon 31 so that the stent does not move relative to the distal end of the catheter. In particular, the stent does not rotate about axis 30.

A field transducer or position sensor 50 is mounted near the distal end 26 of the probe body 22. This field transducer 50
May be a sensor configured to detect a magnetic or electromagnetic field. For example, the sensor 50 can be a multi-axis, solid-state position sensor of the type disclosed in U.S. Pat. No. 5,558,091. Such sensors incorporate a plurality of transducers that sense magnetic field components in directions orthogonal to each other. Other suitable position sensors are described in U.S. Pat.
International Patent Application No. PCT / US9, currently published in US Pat. No. 391,199, and as PCT International Publication No. WO 96/05768, which is incorporated herein by reference.
5/01103. Such a coil may be provided as a single coil or as a plurality of orthogonal coils capable of detecting magnetic field components in orthogonal directions. The position sensor or field transducer 50 is connected to a lead 52 that extends from the proximal end 24 of the body 22 through the hole 28.

The apparatus further includes a set of external field transducers or antennas 54 that define a positioning reference coordinate space. For example, the external field transducer 54 can be mounted on a patient support bed. The antenna 54 is connected to a field transceiver 56 and a computer 58, which is connected to a conventional input device such as a mouse or trackball and keypad or a display device such as a cathode ray tube 60. These elements are configured to cooperate with the field transducer 50 on the probe to determine the placement of the field transducer on the probe, thereby providing the external field transducer or probe 20 in the reference coordinate space of the antenna 54. Can be determined. These elements of the device are disclosed in the aforementioned US Pat. No. 5,558,09.
No. 1 or 5,391,199. Other devices for detecting the placement of a probe with a position sensor by transmitting a non-ionic field are also known in the art.

That is, as is known in the art, an electromagnetic or magnetic field can be transmitted between an antenna or field transducer mounted in an external reference coordinate space and a field transducer on a probe. The placement of the probe can be calculated from the properties of the field detected by the transducer on the probe. Thus, the external field transducer or antenna 54 and the position sensor or probe field transducer on the probe cooperate to form a plurality of transceiver pairs. Each such pair comprises one transmitter and one receiver as a pair of elements. Then, one element of the pair is arranged on the probe, and the other element of the pair is arranged at a known position in the external reference coordinate space. Generally, at least one element of each transmitter-receiver pair is located at a different location or orientation than the corresponding elements of the other pairs. By detecting the transmission characteristics of the field between the various pairs of elements, the system can estimate information about the placement of the probe in the external reference coordinate space. It should be noted that this arrangement information includes both the position and direction of the probe or, most preferably, both the position and direction in all degrees of freedom.

This external field transducer 54
Although shown as attached to a rigid structure, such as a patient bed, so that they remain in a fixed position relative to each other, this is not required. The external field transducers are movable relative to each other, as described in the disclosure of co-pending application WO 97/29685, hereby incorporated by reference. The computer system can be determined by measuring the characteristics of the field transmitted between the transducers or between the external field transducer and a calibration transducer attached to the respective external field transducer.

The apparatus further includes a fixture 70 mounted at a fixed or known location relative to the external field transducer 54. The fitting 70 includes a pocket 72 having a shape adapted to fit into the stent when the stent is in the unexpanded state shown in FIG. This pocket 72 is at a known location and orientation relative to the external field transducer 54.

A plurality of reference markers 62 are also provided. Each marker 62 has characteristics that are visible in the image processing modality used to obtain the image of the affected area. For example, if an X-ray imaging modality is used, the reference marker is radiopaque. Also, when using magnetic resonance imaging, the reference marker has magnetic resonance properties that are different from those of normal body tissue. Each of the fiducial markers 62 also has a field transducer similar to the internal field transducer mounted on the probe. The field transducer incorporated into this fiduciary marker is configured to interact with the external field transducer 54, the field transceiver 56, and the computer 58 in a manner similar to that described above with respect to the internal field transducer 50 on the probe. This computer can determine the position of the reference marker in the same manner as the method of determining the position of the probe tip.

In a method according to one embodiment of the present invention, a fiduciary landmark is placed on a patient and an image of the patient is obtained by the conventional image processing modalities described above. This image includes some patient's bodily tissues, including tubular tissue in need of a stent. For example, as shown in FIG.
The image may include arterial tissue including a main aorta 64 joining two bifurcated arteries 66 and a bifurcated artery 68, typically at a Y-cross. This image also has a reference marker 62
Is included. This image is provided as computer data such as digital information defining the radiopacity or magnetic resonance properties of the individual volume elements of the patient. After this image processing, the patient is placed on the bed 51.

Field transceiver 56 and computer 58 are operated to determine the location of fiducial landmark 62 in the positioning fiducial coordinate space defined by external field transducer 54. For this purpose, the location of the reference marker in the positioning reference coordinate space is provided on the computer. The technician can enter the location of the reference marker in this reference coordinate space. For example, the computer 58 can be operable to display a depiction of an image that includes fiducial markers in two orthogonal planes, and the technician is incorporated into the input device 59 until the cursor is positioned over a particular fiducial marker depiction. The cursor on these depictions can be adjusted manually by adjusting the knob, trackball or mouse.
Once the cursor is aligned with the reference marker depiction, the technician can provide another indication, such as by entering a command through input / output device 59. This signals the computer that the cursor coordinates in the reference coordinate space of the image correspond to the coordinates of the reference marker. If the coordinates of the reference sign are thus given to this computer in the reference coordinate space of the image or in the positioning reference coordinate space,
The computer can derive a mathematical transformation between the positioning reference coordinate space and the image reference coordinate space.

Other techniques for locating the location of the image in the body tissue or for guiding the transformation between the image reference coordinate space and the positioning reference coordinate space are well known and are described in the above patents and publications. ing. In one such technique described in these patents and publications, the patient is not marked during the image processing procedure. Instead, the reference field transducer is manually aligned with some easily identifiable locations in the body tissue included in the image. The location of such an identifiable location in the positioning reference coordinate space is obtained by operating the reference field transducer based on the external field transducer in the same manner as described above. The technician can enter locations of identifiable locations of body tissue in the same manner as described above, so that the computer has locations of these locations in both reference coordinate spaces. In yet another variation, the system obtains a series of positions in the positioning reference coordinate space while moving the reference field transducer over a well-defined contour of the body tissue of the patient. The computer system uses automatic pattern matching techniques to find features having an outer shape that includes a set of locations in the reference coordinate space of the image, the reference coordinate space of the image being determined by a rigid body transformation to a positioning reference coordinate space. A map can be created at that set of locations within the map. Also, various techniques are known in the art for finding matching locations in both of the reference coordinate spaces and for guiding the transformation between the positioning reference coordinate space and the image reference coordinate space.

The stent 38 is disposed at the distal end of the probe by the balloon 31 so that the direction of the stent is fixed with respect to the direction of the field transducer 50. The relationship between the orientation of the stent and the orientation of the field transducer 50 is to orient the stent in a known direction in the positioning reference coordinate space and operate the computer while the stent is in the known direction to operate the field. Register transducer direction
Can be input to the computer. For example,
The distal end of the probe with the stent can be located in the fixture 70 such that the stent is received in the pocket 72.
In this state, the stent is in a known position in the positioning reference coordinate space constituted by the transducer 54. The plane defined by the tubular element axes 40, 46 and the tubular element axis 48 is in the horizontal plane of the fixture, the probe tip and the axis 30 of the main tubular structure of the stent and the axis 40 of the main tubular structure. Extends in a preselected direction defined by the fixture. The position of the stent is fixed with respect to the positioning reference coordinate space. While the probe and stent are in this known configuration, the computer obtains the direction and position of the field transducer 50 on the probe. Field transducer 5 using the same techniques as described above.
The translation between the placement of zero and the orientation of the stent can be calculated, for example, as the translation between the orientation of the field transducer 50 and the plane of the tubular elements and axes 46,48 and the axis 40 of the main tubular structure. . Since the stent remains fixed with respect to the probe, the relationship between the orientation of the stent and the direction of the field transducer on the probe remains fixed during the procedure until the stent is placed in the blood vessel.

The physician then advances the tip of the stented probe into a tubular tissue of the patient's body tissue, such as the main tubular element or artery 64. During this procedure, the pressure control device is operated to fix the space between the stent and the balloon 31 without any gap. As the stent begins to deform, the diameter of the main reinforcement element 38 will increase slightly, and the balloon will inflate correspondingly to maintain close engagement with the stent. The system continuously obtains the location and orientation of the internal field transducer 50 at the probe tip. Using the known relationship between the field transducer placement and the stent placement, the system continuously calculates the stent placement and translates this known placement into a placement in the reference coordinate space of the patient image. . The system continuously displays the outer shape of the stent superimposed on the image in an arrangement corresponding to the actual arrangement of the stent in the reference coordinate space.

This display is shown on a cathode ray tube (CRT) 60. Thus, the display indicates the location and orientation of the stent with respect to the perimeter of the affected tissue, including the perimeter of the tubular tissue or artery. For example, in the condition shown in FIGS. 2 and 3, the stent outline 36 is directed to the branch artery 66 and to the location where the branch artery 68 and the main artery 64 intersect. In this way, the stent outline 36 'is superimposed on the depiction of this intersection. This outer shape 36 'generally shows a Y-shaped configuration. The directions of the axes 40, 46 and 48 are clearly shown in the correct direction relative to the artery. By twisting the proximal end of the catheter body, the physician can adjust the orientation of the stent by rotation about the axis of the main reinforcement element, as indicated by arrow R. This aligns the branch element axis 46 and the branch element axis 48 with the branch tissue or artery 66 and artery 68 of the affected tissue. The physician holds the stent in the correct position and orientation while the stent changes its configuration to the fully expanded state (see FIG. 2). During this phase, the pressure control maintains the engagement of the balloon and the stent.

Once the stent is fully expanded, the physician can remove the stent from the catheter tip. The physician can actuate the pressure control device 34 (see FIG. 1) to guide the balloon or movable element to the removal or deflated position 31 ', after which the catheter can be withdrawn. Also, the physician can gradually change the configuration of the stent so that the diameter of the main reinforcement element 38 is increased while the balloon remains fixed and the stent is removed from the balloon.

In yet another embodiment of the present invention,
The stent comprises the main reinforcement element 138 and the single branch reinforcement element 1
40 is provided. The branch reinforcing element is configured to be collapsed or folded at a position indicated by a solid line in FIG. The stent is engaged with the probe tip 126 and the tubular tissue, such as the main artery or vein 164, is placed until the bifurcation reinforcement element is placed at the opening of the bifurcation 166 of the patient's tubular tissue, such as the bifurcated artery 164. Is guided in the traveling direction via.

Here again, the orientation of the stent is displayed in alignment with the patient's image, and the orientation of the stent about axis 140 of the main reinforcement element is adjusted to align branch reinforcement element 140 with branch tissue 166. it can. Once such alignment is achieved, the probe and stent are pulled back slightly (to the left as seen in FIG. 4) to pass the collapsed branch reinforcement element 140 through the branch tissue or artery 166, and then
The branch reinforcement element expands as shown at 140 "in FIG. 4. The probe of FIG. 4 is fitted with a balloon (not shown) similar to the balloon of the probe shown in FIG. The main reinforcement element 138 can be used to force the expansion and engage the wall of the main tissue or artery 164. Again, it is important to adjust the orientation of the stent during the deployment procedure. This image processing and superposition technique that allows the physician to observe the placement of the stent relative to the patient's body tissue is also valid in this embodiment.

As shown in FIG. 5, the stent may include only a single tubular element 238. However, even with such a stent, it is desirable to provide an indication of the orientation of the stent during deployment. For example, a stent may have patches 240 attached to only a portion of its surface.
The pad or patch 240 may be, for example, a tubular element 2
38, the mesh frame structure 242 constituting the rest
May be applied to cover the opening of the aneurysm or fistula while still covering the rest of the vessel wall. Here, the direction and position of the stent with respect to the diseased tissue can also be displayed by, for example, superimposing the outer shape of the stent on the depiction of the internal tissue as described above. The physician can align the patch 240 with the opening to be closed.

In the configuration of FIG. 5, the orientation of the stent relative to the tip 226 of the probe body is secured by a key or key 227 on the probe body that engages a groove or slot 229 in the stent. Thus, the orientation of this stent relative to the field transducer 250 is known, and there is no need to determine the relative orientation of these elements during use of the device by use of the fixture 70 (see FIG. 3).

Other arrangements for securing the stent in a known direction may be used. For example, the tip of the probe may have a non-circular cross-section, and the stent may have a corresponding non-circular cross-section. Also, in the configuration of FIG.
It is held at the distal end of the probe by a set of locking or locking fingers 233 movably attached to the distal end of the probe body. An actuation knob 235 and a finger 233 are provided by a mechanical coupling in the form of a cable 239 extending along the probe hole to its proximal end 224.
Is connected. The physician can remove the stent by moving the activation knob to swing the finger 233 into the folded or released position. Note that the form of the movable element used to hold the stent at the tip of the probe can be varied. Also, the probe tip may use another device, such as another mechanical, pneumatic or electrical actuator. The actuator provided at the proximal end can be changed accordingly. For example, when using an electrical device at the distal end to move the element and remove the stent, the proximal actuator may include a switch or pair of contacts that can be connected to a switch or other power source.

According to another variant, the movable element may be omitted if the stent itself detaches itself from the probe. For example, as described above with respect to FIGS. 1-3, if the stent is a self-expanding stent made from a shape memory alloy, the movable elements may be omitted. Also, if the stent gets stuck in the body tissue during the probe's approaching movement, the probe can be moved in the opposite direction to detach the probe from the stent and leave the stent in place.

In the embodiment described above, the stent is placed in the tissue of the vascular system. However,
The stent may be placed in any tubular tissue of the body, including the esophagus and other parts of the digestive tract or the respiratory tract. If the stent needs to be placed in the area of the respiratory system while the patient is breathing normally, the system provides a so-called "motion artifact" that occurs when thoracic tissue changes size and shape during breathing. artifact) ". It is hereby incorporated by reference and filed on the same date as this specification, entitled “Image-Guided Thora
cic Therapy and Apparatus Therefore) ''
d as disclosed in co-pending U.S. patent application co-pending on E. Acker and as disclosed in U.S. Provisional Patent Application No. 60 / 038,497, filed February 25, 1997. In addition, it is possible to remove the motion artifact generated by the exercise by breathing. The system can be operated to perform probe tip placement when the patient is in the same phase as the respiratory cycle during image acquisition. Other, more complex, approaches to reducing motion artifacts are also known.

The above-mentioned International Patent Application No. PCT / US9
As described in 7/02335, a probe carrying a stent can be used with another probe, referred to as a "site probe." The site probe can be placed in the body at a location near the location where the stent is placed,
The computer system can provide information indicating the placement of the stent-carrying probe to the site probe.
For example, the site probe can include a balloon or other occlusion device that stops flow through the artery during stent deployment. The relative placement information is used to guide the stent-carrying probe to a predetermined position. Also,
This stent-carrying probe can function as a site probe, and yet another probe is guided to the stent site based on the relative site information.

According to yet another embodiment of the present invention, stent 336 (see FIG. 6) may have a field transducer 350 mounted thereon. An electrical lead 339 or other signal conductor, such as an optical fiber, extends from the stent through the interior of the probe 320 to the proximal end of the probe and is accessible outside the patient's body during stent deployment. It has become. The placement of this stent can be monitored during stent placement in the same manner as described above. This signal conductor may extend out of the body after stent placement or may be implanted under the skin or at another easily accessible location. Thus, transducer 350 can be used to determine stent placement. Thus, after placement of the stent, this capability can be used to position the stent if it has moved, or to ensure that the stent remains in the correct location. In addition, a transducer-mounted stent was purchased from International Patent Application No. PCT.
/ US97 / 02335 can also be used as a site probe to guide another stent to the location of the stent based on the placement of the other probe relative to the stent.

The above and other variants and combinations of the above features can be used without departing from the invention, as defined in the claims. It should be noted that the above-described preferred embodiments are shown by way of example, not limitation, and are defined by the scope of the present invention.

The specific embodiments of the present invention are as follows. (1) (a) penetrating the probe carrying the stent into the tubular body tissue; and (b) determining the placement of the stent with respect to the patient, the determining step comprising one or more non-ionic A field to or from at least one internal field transducer on the probe or the stent, detecting each such transmitted field, and determining at least one of the characteristics of the detected field. (C) determining the stent from the probe when the determining step indicates that the stent is in a predetermined position with respect to the tubular tissue; Removing the stent from the tubular tissue in the body of the patient. (2) The method according to embodiment (1), wherein the determining step includes determining an orientation of the stent with respect to the diseased part. (3) the tubular body tissue includes a main tube having a long axis, and the step of determining the placement of the stent includes the step of determining whether the stent is disposed at least partially within the main tube; The method of claim 1 comprising determining the direction of the stent that rotates about the long axis. (4) the tubular tissue comprises one branch tube intersecting the main tube, the stent comprises one main reinforcement element and one branch reinforcement element intersecting the main reinforcement element, the method comprising: Adjusting the orientation of the stent based on the determined placement of the stent such that the main reinforcement element is disposed in the main tube while the branch reinforcement element is disposed in the branch tube of the tubular element. The method according to aspect (3). (5) the tubular tissue includes a plurality of branch pipes intersecting the main pipe, the stent includes one main reinforcing element and a plurality of branch reinforcing elements crossing the main reinforcing element, and the method includes: Adjusting the orientation of the stent based on the determined placement of the stent such that a stiffening element is located in the main vessel, while the branch stiffening element is located in one of the branch tubes of the tubular element. The method according to embodiment (3).

(6) The method according to the embodiment (5), wherein the branch tissue is Y-shaped. (7) The method according to embodiment (5), wherein the bifurcated tissue is a conduit or respiratory tissue. (8) The method according to embodiment (1), wherein the branching tissue is a tissue of a vascular system, a digestive tract, or a respiratory system. (9) The method of embodiment (1), wherein determining the placement of the stent relative to the patient comprises superimposing the stent or probe profile on the patient image. (10) The method according to claim 1, wherein the determining step comprises the step of: determining between the internal field transducer and one or more additional field transducers defining a positioning reference coordinate space.
An embodiment (9) comprising transmitting more than one field, determining a placement of the probe in the positioning reference coordinate space, and converting the placement of the probe and the image to a common reference coordinate space. Method.

(11) The method of embodiment (10), wherein said one or more additional field transducers comprises at least one external field transducer mounted externally to the patient's body. (12) The method of embodiment (1), wherein the internal field transducer is attached to the stent, and the internal field transducer is left on the stent in a patient after removing the stent from the probe. (13) The method of embodiment (12), further comprising determining the stent placement after detaching the stent by transmitting one or more fields to or from the internal field transducer. 14. The device of claim 1, wherein the stent comprises an elongated main reinforcement structure and a bifurcation intersecting the main reinforcement structure. 15. The method of claim 14, wherein a portion of the probe near the distal end has an elongated axis and the axis of the main reinforcement structure is aligned with the elongated axis of the probe. .

(16) The apparatus according to claim 1, wherein the stent comprises a main reinforcing structure having an axis and a plurality of branch reinforcing structures having an axis inclined to the axis of the main reinforcing structure. (17) an engagement element movably attached to the distal end of the probe by the probe, and selectively from the base end of the probe for moving the engagement element to release the stent from the probe. The apparatus of claim 1, further comprising: 18. The apparatus of claim 1, wherein the at least one field transducer comprises a multi-axis magnetic field transducer adapted to detect a magnetic field component or emit the component in multiple directions. (19) The device of claim 1, wherein the at least one field transducer comprises at least one field transducer attached to the stent. (20) The apparatus of claim 1, wherein the at least one internal field transducer is attached to the probe.

[0044]

As described above, according to the present invention, a complex stent having one or more bifurcated portions, which must conform to the shape of the affected tissue, can be accurately placed. . Therefore, it can be used in medicine and related procedures. Also, the stent can be placed in the body without the patient or physician being exposed to non-ionic radiation.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view showing an apparatus according to an embodiment of the present invention.

2 is an enlarged schematic cross-sectional view showing a portion of the device of FIG. 1 in connection with the body tissue of the present invention.

FIG. 3 is a schematic perspective view showing another element that can be used in the apparatus of FIG. 1;

FIG. 4 is a schematic sectional view showing a device part according to another embodiment of the present invention;

FIG. 5 is a perspective view showing an apparatus according to still another embodiment.

FIG. 6 is a perspective view showing an apparatus according to another embodiment of the present invention.

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Claims (2)

[Claims] 1. An elongate probe having a distal end and a proximal end, wherein the distal end of the probe is adapted to be inserted into a tubular tissue of a body tissue of a patient, and the probe of the probe. A stent removably disposed near a distal end, and at least one stent mounted on the stent or the probe near the distal end;
Field transducers, wherein the probe comprises at least one field transducer including one or more signal transmission paths extending from the at least one field transducer toward the proximal end of the probe. A device for placing a stent. 2. A field transducer having a field transducer thereon, the field transducer being adapted to detect or emit one or more non-ionic fields, and adapted to be placed in the affected tubular tissue. Stent.