Integrated catheter for diverse in situ tissue therapy

An integrated catheter assembly for enabling diverse in situ therapies includes a catheter with an irrigation fluid lumen, a distal tip portion that acts as a hemostat and a needle for injection therapy that extends through the catheter lumen and a lumen in the distal tip portion. A needle hub structure carries the catheter and provides a sealing entrance for a needle that can be displaced between extended and retracted positions. The needle and electrodes are electrically isolated. The apparatus provides a physician the options of irrigating tissue, cauterizing tissue or injecting tissue without the need for removing the apparatus from the working channel of an endoscope.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention generally relates to electro-coagulation of tissue in the 
body in combination with other forms of therapy using catheters. 
2. Description of Related Art 
It is very important to minimize the time required to stop internal 
bleeding in a patient. A physician has several medical instruments in his 
or her armamentarium for stopping such internal bleeding. In accordance 
with one modality that is particularly suited for bleeding into the 
gastrointestinal tract, a physician initially positions a flexible 
endoscope in the patient with its distal end proximate a hemorrhaging 
vessel. The physician may insert an irrigator through a working channel in 
the endoscope to clear the area by administering saline solution as a 
precursor to any attempts to stop bleeding. If the instrument being used 
for irrigation is like the Gold Probe.TM. hemostat manufactured by Boston 
Scientific Corporation, the assignee of this invention, the physician may 
then cauterize the bleeding vessel using a distally positioned hemostat. 
Such instruments are constructed to be employed through a working channel 
of an endoscope to seal potential bleeding sites as in the 
gastrointestinal tract or the esophagus. Other hemostats use 
mono-electropolar electrodes in which one electrode is carried by a 
catheter to a site while the other electrode is an exterior ground plate 
placed in a patient. Alternatively the physician may retract the 
irrigating catheter and insert an elongated needle through the endoscope 
to inject a vaso-constrictor into the vessel to slow hemorrhaging. Then 
the physician could remove the elongated needle and reinsert the hemostat 
to finish the operation. 
The above-mentioned Gold Probe.TM. hemostat is an example of a device that 
supplies a suitable current density and wave form of radiofrequency energy 
to perform electro-coagulation or cauterization. It utilizes a catheter 
with a bipolar electrode assembly located on a distal flexible tip formed 
of a ceramic cylinder having a hemispherical end. The ceramic tip includes 
a pair of spaced gold spiral electrodes applied to its cylindrical surface 
and domed end. RF energy applied to the electrodes produces a current 
through adjacent tissue that heats and cauterizes the hemorrhaging vessel 
which is contacted by the tip of the catheter. 
Notwithstanding the fact that both hemostasis and injection needle therapy 
are usually done on an emergency basis, the exchange of catheters to 
provide different functions continues and increases the risk to the 
patient because the time to complete therapy is extended. Extending the 
time to complete the therapy also increases patient discomfort. 
Consequently, physicians have to weigh the time, complexity and benefits 
of interchanging single or dual purpose catheters to change treatment 
modalities against whatever disadvantage may result by working with a 
single modality and single catheter. 
Co-pending application Ser. No. 08/038,903 that is incorporated herein by 
reference provides a catheter generally characterized by an axially 
displaceable probe that acts as one of two electrodes for performing 
hemostatic therapy. The other electrode is spaced proximally from and is 
insulated with respect to the probe. The catheter has a lumen for 
administering irrigating fluids to tissue at the hemorrhaging vessel. In 
some embodiments irrigation fluid passes between the main probe and a 
structure at the distal end of the catheter. In other applications the 
distal tip portion includes separate passages for allowing an irrigating 
solution to pass into the area of the hemorrhaging vessel. In still 
another embodiment the irrigation fluid passes directly through the probe 
that comprises a hollow needle that also acts as an electrode and as an 
injection needle for administering a vasoconstrictor or other therapeutic 
agent into a bleeding vessel. 
This apparatus, therefore, in its various embodiments, enables a physician 
to irrigate tissue and to treat a hemorrhaging vessel with injection 
therapy or hemostatic therapy without removing the catheter apparatus from 
the working channel or lumen of an endoscope. However, many physicians are 
familiar with standard devices such as the Gold Probe hemostat. One 
particular embodiment of Ser. No. 08/038,903, that is applied to a Gold 
Probe hemostat discloses a probe tip with two separate electrodes and an 
extensible conductive probe that provides a physician alternatives for 
hemostatic therapy. In accordance with one option the probe tip electrodes 
constitute bipolar electrodes and the extensible conductive probe is 
inactive electrically. In accordance with the other option the extensible 
probe is active and one or both of the probe tip electrodes act as a 
second electrode. This approach can complicate the apparatus required for 
connecting an RF generator source to the electrodes and related circuitry 
and can also increase the burden on the physician using the apparatus. 
Moreover, such procedures differ from those familiar to the physician as a 
result of use of prior art devices, so such a catheter assembly can impose 
other complications. 
SUMMARY 
Therefore it is an object of this invention to provide an integrated 
catheter assembly that enables a physician to select among hemostatic and 
injection therapies. 
Another object of this invention is to provide an integrated catheter 
assembly that enables a physician to irrigate tissue selected for 
treatment and to optionally select between hemostatic and injection 
therapy. 
Still another object of this invention is to provide an integrated catheter 
assembly that facilitates therapy of bleeding vessels and that simplifies 
the required procedures for such therapy. 
Yet another object of this invention is to provide an integrated catheter 
assembly that enables a physician wide flexibility in the treatment of 
hemorrhaging vessels and that utilizes the standard operating 
characteristics of conventional single purpose or dual purpose assemblies. 
In accordance with this invention, an integrated catheter assembly that 
enables a physician to utilize diverse in situ therapy modalities at 
selected tissue sites includes catheter, bipolar electrode tip and 
injection needle structures. A lumen extends from a proximal end to a 
distal end of the catheter structure to provide a passage from a location 
externally of the patient to the tissue being treated. The bipolar 
electrode structure attaches to the distal end of the catheter structure 
and provides hemostatic therapy to selected tissue. The electrode 
structure additionally has a central lumen aligned with the catheter lumen 
for enabling the transfer of irrigation fluids to tissue being treated. 
The injection needle structure is electrically isolated from the bipolar 
electrode means and extends from a proximal end externally of the patient 
through the lumens in the catheter and the bipolar electrode structure for 
axially displacement relative to the catheter and bipolar electrode 
structures. The needle structure can be extended distally beyond and can 
be retracted proximally of a distal end surface of the bipolar electrode 
structure.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
FIG. 1 discloses an integrated catheter assembly 10 that enables a 
physician to utilize diverse in situ therapy modalities at selected tissue 
sites without withdrawing the assembly 10 from the working channel or 
lumen of an endoscope. It includes a modified bipolar hemostat and 
irrigation system 11, such as the above identified Gold Probe hemostat. 
The system 11 enables a physician to utilize a dual purpose device for 
bipolar hemostasis and irrigation in the treatment of a bleeding vessel. 
The system 11 particularly includes a catheter 12 with a single lumen that 
extends from a distal location 13 to a proximal location 14. At the 
proximal location 14 a catheter hub 15 carries the catheter 12 from a Leur 
lock or similar catheter fitting 16 toward the distal location 13. 
Electrical leads 17 from an RF generator connector 18 also enter the 
catheter hub 15. RF generators of the type utilized with this apparatus 
are well known and therefore not shown. The electrical leads 17 are led 
into the center of the catheter 12 in the hub 15 thereby to be carried 
through a central lumen 19 of the catheter 12 to the distal location 13 
and a bipolar electrode assembly 20. As an alternative, the catheter 12 
may incorporate electrical leads in the catheter wall thereby to eliminate 
any contact between irrigating solutions in the lumen 19 and the 
electrical leads 17. The bipolar electrode assembly 20 when energized over 
the electrical leads 17 provides hemostatic therapy. 
In accordance with this invention, a needle hub 21 directs the catheter 12 
therethrough and supports the proximal end of a needle assembly 22 that 
includes an injection needle 23. The injection needle 23 can move between 
extended and retracted positions by manipulation of an operator 24. The 
operator 24 is shown at its extended position in FIG. 1 by the solid lines 
and in its retracted position by phantom operator 24'. When the needle 23 
extends distally beyond the distal end of the bipolar electrode assembly 
20 as shown in FIGS. 1 and 3, it can penetrate tissue and enable a 
physician to administer a vasoconstrictor or similar agent through a lumen 
25 in the injection needle 23. 
Referring now to different sections of the apparatus shown in FIG. 1 in 
more detail, FIGS. 2 and 3 depict a distal end location 13 of the 
integrated catheter assembly 10. In each of FIGS. 2 and 3 the distal end 
of the catheter 12 terminates at the bipolar electrode assembly 20. 
More specifically the bipolar electrode assembly 20 includes a cylindrical 
body portion 26 having a hemispherical distal end tip 27 and a proximally 
extending shank 28 at its other end. Discrete spiral electrodes 29A and 
29B are disposed on the outer surface of the body portion 26 and the end 
tip 27 and connect to the electrical leads 17. A distal tip lumen 30 
extends through the body portion end tip 27 and shank 28. The shank 28 is 
nested and supported by the catheter 12. 
Still referring to FIGS. 2 and 3, a needle guide portion 31 includes an end 
section 32 that is located in the proximal end of the lumen 30 and 
coextensive with a portion of the shank 28. The needle guide portion 31 
extends proximally from the shank 28 and constitutes a pervious guide tube 
for the needle 23. More specifically, the needle guide 31 is formed as a 
spring with multiple spaced turns that define inter-turn passages 33. 
These passages 33 allow fluid to transfer from the catheter lumen 19 and 
through the distal tip lumen 30 to exit from the end tip 27. Fluid flow is 
relatively unimpeded in the structure shown in FIG. 2 when the injection 
needle 23 is retracted. The extension of the needle 23 to the position 
shown in FIG. 3 restricts the distal tip lumen 30, but flow can still 
occur. 
FIG. 4 depicts an alternative embodiment for the bipolar electrode assembly 
20. In this particular embodiment, a tube 34 replaces the spring 31. The 
tube 34 has a section 35 that fits in the lumen 30 and is coextensive with 
a portion of the shank 27 and another section 36 that is proximal of the 
shank 27. This second section 36 includes a plurality of radially 
extending apertures 37 that act as passages for irrigation fluids from the 
catheter 12 through a central lumen 38. 
Thus each of FIGS. 2 through 4 depict alternative embodiments of a bipolar 
electrode assembly 20 that includes first and second electrodes 29A and 
29B for providing hemostatic therapy. In each embodiment a body portion 26 
has a hemispherical distal end 27 and carries the electrodes 29A and 29B. 
A shank 28 extends proximally of the body portion 26 for insertion of the 
lumen 19 at the distal end of the catheter 12. A tubular pervious needle 
guide 31 extends proximally from the shank portion 28 in the lumen 19 to 
be coextensive with the distal portion of the catheter 12 for supporting 
the distal end of the injection needle 23 particularly in its retracted 
position. 
Referring to FIG. 1, the operator 24 associated with the needle assembly 22 
includes a proximal end fitting 40 that can connect to a syringe or other 
apparatus for enabling the injection of a vasoconstrictor or other 
therapeutic agent through the needle lumen 25- At its opposite end, the 
operator 24 includes a collar 41 and set screw 42 or other attaching 
apparatus for affixing the operator 24 to the needle 23. Such apparatus is 
known in the art. In this particular embodiment the operator 24 and needle 
23 lie along an axis 43. 
The needle hub 21 can be molded or otherwise formed to include a proximal 
compartment 44 defined by side walls 45 and 46 and end walls 47 and 48. An 
aperture 50 through the end wall 48 accommodates the operator 24 while an 
aperture 51 at the distal end wall 47 accommodates the needle 23. The end 
walls 47 and 48 support the proximal end of the needle assembly 22 and 
limit the range of travel of the operator 24 along the axis 43 between the 
position shown in FIG. 1 wherein the collar 41 abuts the wall 47 and a 
retracted position in which the collar 41 abuts the end wall 50. 
An intermediate compartment 52 disposed distally of the proximal 
compartment 44 supports the catheter 12 in a radiused orientation. Curved 
and straight side walls 53 and 54 of the needle hub 21 and transverse end 
walls 55 and 56 define the compartment. The end wall 55 extends between 
the side wall 53 and 54; the end wall 56, between the side wall 53 and the 
intersection of the side wall 45 and end 47. Apertures 57 and 58 in the 
end walls 55 and 56 respectively capture the catheter 12. 
An elastomeric seal 60 surrounds the catheter 12 and is located in the 
intermediate compartment 52. The needle 23 penetrates the seal 60 and the 
wall of the catheter 12 thereby to be located in the catheter lumen 19 to 
extend through the distal tip 30 as shown in FIG. 2. The seal 60 prevents 
leakage from the catheter 12 even during axial displacement of the needle 
23 along the axis 43. This seal 60 generally will be formed of an 
elastomeric material and can take any of several forms as known in the 
art. 
The needle hub 21 includes another proximal compartment 61 adjacent the 
proximal compartment 44. The compartment 61 is formed by a proximal end 
wall 62, the side walls 45 and 53 and the end wall 57. The end walls 57 
and 62 in this compartment 61 support the catheter 12 proximally of the 
seal 60 and, with the compartment 52 and end wall 55, provides an angular 
offset to the catheter 12 with respect to the axis 43. 
A distal compartment 64 is formed by the side walls 53 and 54, the end wall 
55 and a distal end wall 65. An aperture 66 in the end wall 65 holds the 
catheter 12. The end walls 55 and 65 thereby maintain the alignment of the 
catheter 12 along the axis 43 to facilitate the placement and containment 
of the needle 23 within the catheter 12 lumen 19 distally of the needle 
hub 21. 
Still referring to FIG. 1, it is desirable to manufacture the needle hub 21 
as a standard unit for a variety of applications. In some applications, 
the limits imposed on the axial travel of the injection needle 23 by the 
end walls 47 and 48 may allow an extension of the needle 23 from the 
bipolar electrode assembly 20 that is greater than desired. It is possible 
to customize that extension by applying a positive stop structure to the 
injection needle assembly 22. One such structure is shown in FIGS. 2, 3 
and 5 where like numbers refer to like elements. As shown the needle 
assembly 22 particularly in FIG. 5 includes the operator 24 with its end 
fitting 40 and collar 41. The injection needle 23 extends as a constant 
diameter tube to its distal end 67. A collar 70 having a distal, radially 
extending end surface 71 is located on the needle 253 at some 
predetermined location spaced from the distal end 67 by a distance that 
equals the length of the desired extension plus the distance between the 
end tip surface 27 of the bipolar electrode assembly 20 as shown in FIG. 1 
and a proximal end 72 of the needle guide 31 as shown in FIGS. 2 and 3. 
Consequently as the injection needle 23 moves from its retracted position 
in FIG. 2 to its extended position in FIG. 3, the distal end surface 71 of 
the collar 70, that overlies the spring 31, abuts the end 72 and prevents 
any further distal extension of the needle 23. If the bipolar electrode 
assembly 20 of FIG. 4 were used, the end surface 71 would abut an end 
surface 73 on the tube 34. 
FIG. 6 discloses an alternative stop mechanism wherein the needle assembly 
22 includes an operator 24 with proximal end connector 40 and distal 
collar 41. In this embodiment the needle assembly 22 comprises a distal 
hollow section 74 and a proximal hollow section 75. The distal section 74 
has a given diameter corresponding to the diameter of the needle 23 shown 
in FIG. 5 and determined by the application requirements. The length of 
the distal section 74 equals the desired extension of the needle plus the 
distance from the distal end tip 27 to either end surface 72 of the spring 
31 in FIGS. 2 and 3 or the end surface 73 of the tube 34 in FIG. 4. The 
proximal section 75 extends from the distal portion 74 to the operator 24 
and has a larger diameter. Consequently the proximal portion 75 forms an 
annular radial surface 76 at its distal end that also will abut either the 
end 72 of the spring 31 in FIGS. 2 and 3 or the end 73 of the needle guide 
tube 34 shown in FIG. 4. 
When a physician needs to treat a patient with internal bleeding, the 
physician will, as in the prior art, insert an endoscope with a working 
channel. Then the physician can insert the integrated catheter apparatus 
10 shown in FIG. 1 through the working channel, normally with the 
injection needle 23 in its retracted position (as shown in FIG. 2). If it 
is necessary to irrigate the area, the physician can apply irrigating 
fluid through the connector 16 and the catheter lumen 19 to be ejected at 
the distal end tip 27 through the lumen 30 as shown in FIGS. 2 and 3. If 
upon viewing the site the physician decides to utilize hemostasis, it is 
merely necessary to position the bipolar electrode assembly 20 at the 
tissue and energize the electrodes 29A and 29B. The needle assembly 22 has 
no effect on this process. If, on the other hand, the physician determines 
the injection of a vasoconstrictor is appropriate before or in lieu of 
hemostasis, the physician can easily extend the injection needle 23 and 
administer a therapeutic agent through the connector 40 and the needle 23. 
Thereafter the physician can irrigate the site at will and elect to use 
hemostasis in addition to injection therapy. All these decisions are made 
and elections pursued without withdrawing the integrated catheter 
apparatus 10 from the endoscope. Moreover, each component requires the 
same basic manipulations as prior art devices familiar to a physician. 
Consequently time otherwise lost in manipulating individual elements in 
and out of the endoscope or in assuring proper operation of other combined 
apparatus is eliminated. This reduces the time for therapy and decreases 
the discomfort of the patient. 
It will be helpful to describe some specific embodiments of this invention 
for the purpose of further understanding the construction and use of this 
invention. In certain specific embodiments, for example, the catheter 
assembly 10 can comprise a 7 Fr. or 10 Fr. catheter 20 and a 21 gauge 
needle 23. In an another embodiment, using a needle as shown in FIG. 6, 
the distal needle portion comprises a 23-25 gauge tubular structure while 
the proximal portion comprises a 21 to 22 gauge tubular structure. In 
addition, one embodiment of the catheter assembly 10 in FIG. 1 extends 
about 250 cm. between the distal tip portion 13 and the hub 21 while the 
extension of the needle 23 from the bipolar electrode assembly is limited 
to a maximum of 6 mm. 
Although this invention has been described in terms of a specific 
embodiment, and certain modifications, still other modifications can be 
made. For example, needle assembly 22 can comprise a one-piece metal 
structure in the form shown in FIG. 5. In the form shown in FIG. 6 the 
distal portion might be constructed of a metal while the proximal portion 
75 might be constructed of plastic. The needle assembly 22 also may 
include means for preventing rotation about the axis 43 during use. Thus 
it will be apparent that these and other modifications can be made to the 
disclosed apparatus without departing from the invention. Therefore, it is 
the intent of the appended claims to cover all such variations and 
modifications as come within the true spirit and scope of this invention.