DELIVERY OF BIOLOGICAL COMPOUNDS TO ISCHEMIC AND/OR INFARCTED TISSUE
The delivery of biological compounds to ischemic and/or infarcted tissue are described herein where such a system may include a deployment catheter and an attached imaging hood deployable into an expanded configuration. In use, the imaging hood is placed against or adjacent to a region of tissue to be imaged in a body lumen that is normally filled with an opaque bodily fluid such as blood. A translucent or transparent fluid, such as saline, can be pumped into the imaging hood until the fluid displaces any blood, thereby leaving a clear region of tissue to be imaged via an imaging element in the deployment catheter. Additionally, any number of therapeutic tools can also be passed through the deployment catheter and into the imaging hood for performing any number of procedures on the tissue for identifying, locating, and/or accessing ischemic and/or infarcted tissue.
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This application claims the benefit of priority to U.S. Provisional Patent Application No. 60/821,117 filed Aug. 1, 2006, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTIONThe present invention relates generally to medical devices used for accessing, visualizing, and/or treating regions of tissue within a body. More particularly, the present invention relates to methods and apparatus for locating and accessing ischemic and/or infracted tissue and for treating the tissue by delivering biologically active compounds within a patient heart.
BACKGROUND OF THE INVENTIONConventional devices for accessing and visualizing interior regions of a body lumen are known. For example, ultrasound devices have been used to produce images from within a body in vivo. Ultrasound has been used both with and without contrast agents, which typically enhance ultrasound-derived images.
Other conventional methods have utilized catheters or probes having position sensors deployed within the body lumen, such as the interior of a cardiac chamber. These types of positional sensors are typically used to determine the movement of a cardiac tissue surface or the electrical activity within the cardiac tissue. When a sufficient number of points have been sampled by the sensors, a “map” of the cardiac tissue may be generated.
Another conventional device utilizes an inflatable balloon which is typically introduced intravascularly in a deflated state and then inflated against the tissue region to be examined. Imaging is typically accomplished by an optical fiber or other apparatus such as electronic chips for viewing the tissue through the membrane(s) of the inflated balloon. Moreover, the balloon must generally be inflated for imaging. Other conventional balloons utilize a cavity or depression formed at a distal end of the inflated balloon. This cavity or depression is pressed against the tissue to be examined and is flushed with a clear fluid to provide a clear pathway through the blood.
However, such imaging balloons have many inherent disadvantages. For instance, such balloons generally require that the balloon be inflated to a relatively large size which may undesirably displace surrounding tissue and interfere with fine positioning of the imaging system against the tissue. Moreover, the working area created by such inflatable balloons are generally cramped and limited in size. Furthermore, inflated balloons may be susceptible to pressure changes in the surrounding fluid. For example, if the environment surrounding the inflated balloon undergoes pressure changes, e.g., during systolic and diastolic pressure cycles in a beating heart, the constant pressure change may affect the inflated balloon volume and its positioning to produce unsteady or undesirable conditions for optimal tissue imaging.
Accordingly, these types of imaging modalities are generally unable to provide desirable images useful for sufficient diagnosis and therapy of the endoluminal structure, due in part to factors such as dynamic forces generated by the natural movement of the heart. Moreover, anatomic structures within the body can occlude or obstruct the image acquisition process. Also, the presence and movement of opaque bodily fluids such as blood generally make in vivo imaging of tissue regions within the heart difficult.
Other external imaging modalities are also conventionally utilized. For example, computed tomography (CT) and magnetic resonance imaging (MRI) are typical modalities which are widely used to obtain images of body lumens such as the interior chambers of the heart. However, such imaging modalities fail to provide real-time imaging for intra-operative therapeutic procedures. Fluoroscopic imaging, for instance, is widely used to identify anatomic landmarks within the heart and other regions of the body. However, fluoroscopy fails to provide an accurate image of the tissue quality or surface and also fails to provide for instrumentation for performing tissue manipulation or other therapeutic procedures upon the visualized tissue regions. In addition, fluoroscopy provides a shadow of the intervening tissue onto a plate or sensor when it may be desirable to view the intraluminal surface of the tissue to diagnose pathologies or to perform some form of therapy on it.
Thus, a tissue imaging system which is able to provide real-time in vivo access to and images of tissue regions within body lumens such as the heart through opaque media such as blood and which also provide instruments for therapeutic procedures upon the visualized tissue are desirable.
SUMMARY OF THE INVENTIONA tissue imaging and manipulation apparatus that may be utilized for procedures within a body lumen, such as the heart, in which visualization of the surrounding tissue is made difficult, if not impossible, by medium contained within the lumen such as blood, is described below. Generally, such a tissue imaging and manipulation apparatus comprises an optional delivery catheter or sheath through which a deployment catheter and imaging hood may be advanced for placement against or adjacent to the tissue to be imaged.
The deployment catheter may define a fluid delivery lumen therethrough as well as an imaging lumen within which an optical imaging fiber or assembly may be disposed for imaging tissue. When deployed, the imaging hood may be expanded into any number of shapes, e.g., cylindrical, conical as shown, semi-spherical, etc., provided that an open area or field is defined by the imaging hood. The open area is the area within which the tissue region of interest may be imaged. The imaging hood may also define an a traumatic contact lip or edge for placement or abutment against the tissue region of interest. Moreover, the distal end of the deployment catheter or separate manipulatable catheters may be articulated through various controlling mechanisms such as push-pull wires manually or via computer control
In operation, after the imaging hood has been deployed, fluid may be pumped at a positive pressure through the fluid delivery lumen until the fluid fills the open area completely and displaces any blood from within the open area. The fluid may comprise any biocompatible fluid, e.g., saline, water, plasma, Fluorinert™, etc., which is sufficiently transparent to allow for relatively undistorted visualization through the fluid. The fluid may be pumped continuously or intermittently to allow for image capture by an optional processor which may be in communication with the assembly.
One particular application for the tissue visualization system includes utilizing the system for detecting the presence and/or location of ischemic and/or infarcted tissue by visual inspection and/or measurement of one or more parameter of the tissue. Any number of physiologic parameters can be utilized to obtain measurements of the visualized tissue to detect the certain parameters, e.g., partial pressure values of oxygen (PO2) and carbon dioxide (PCO2); temperature differences between tissue regions; biomarkers indicative of injured tissue; electrical current and/or electrical potential differences through the tissue; variations in tissue surface hardness and deflection between tissue regions; etc.
Once the injured tissue region has been identified, a number of treatments may be utilized for injecting or infusing bioactive agents into or upon the tissue. Accordingly, a number of systems and methods for utilizing instruments to locate and/or access ischemic and/or infarcted tissue and to treat the tissue by delivering biologically active compounds may be utilized.
BRIEF DESCRIPTION OF THE DRAWING
A tissue-imaging and manipulation apparatus described below is able to provide real-time images in vivo of tissue regions within a body lumen such as a heart, which is filled with blood flowing dynamically therethrough and is also able to provide intravascular tools and instruments for performing various procedures upon the imaged tissue regions. Such an apparatus may be utilized for many procedures, e.g., facilitating trans-septal access to the left atrium, cannulating the coronary sinus, diagnosis of valve regurgitation/stenosis, valvuloplasty, atrial appendage closure, arrhythmogenic focus ablation, among other procedures. Details of tissue imaging and manipulation systems and methods which may be utilized with apparatus and methods described herein are described in U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005 (U.S. Pat. Pub. No. 2006/0184048 A1), which is incorporated herein by reference in its entirety.
One variation of a tissue access and imaging apparatus is shown in the detail perspective views of
When the imaging and manipulation assembly 10 is ready to be utilized for imaging tissue, imaging hood 12 may be advanced relative to catheter 14 and deployed from a distal opening of catheter 14, as shown by the arrow. Upon deployment, imaging hood 12 may be unconstrained to expand or open into a deployed imaging configuration, as shown in
Imaging hood 12 may be attached at interface 24 to a deployment catheter 16 which may be translated independently of deployment catheter or sheath 14. Attachment of interface 24 may be accomplished through any number of conventional methods. Deployment catheter 16 may define a fluid delivery lumen 18 as well as an imaging lumen 20 within which an optical imaging fiber or assembly may be disposed for imaging tissue. When deployed, imaging hood 12 may expand into any number of shapes, e.g., cylindrical, conical as shown, semi-spherical, etc., provided that an open area or field 26 is defined by imaging hood 12. The open area 26 is the area within which the tissue region of interest may be imaged. Imaging hood 12 may also define an atraumatic contact lip or edge 22 for placement or abutment against the tissue region of interest. Moreover, the diameter of imaging hood 12 at its maximum fully deployed diameter, e.g., at contact lip or edge 22, is typically greater relative to a diameter of the deployment catheter 16 (although a diameter of contact lip or edge 22 may be made to have a smaller or equal diameter of deployment catheter 16). For instance, the contact edge diameter may range anywhere from 1 to 5 times (or even greater, as practicable) a diameter of deployment catheter 16.
The imaging and manipulation assembly 10 may additionally define a guidewire lumen therethrough, e.g., a concentric or eccentric lumen, as shown in the side and end views, respectively, of
In operation, after imaging hood 12 has been deployed, as in
As seen in the example of
Although contact edge 22 need not directly contact the underlying tissue, it is at least preferably brought into close proximity to the tissue such that the flow of clear fluid 28 from open area 26 may be maintained to inhibit significant backflow of blood 30 back into open area 26. Contact edge 22 may also be made of a soft elastomeric material such as certain soft grades of silicone or polyurethane, as typically known, to help contact edge 22 conform to an uneven or rough underlying anatomical tissue surface. Once the blood 30 has been displaced from imaging hood 12, an image may then be viewed of the underlying tissue through the clear fluid 30. This image may then be recorded or available for real-time viewing for performing a therapeutic procedure. The positive flow of fluid 28 may be maintained continuously to provide for clear viewing of the underlying tissue. Alternatively, the fluid 28 may be pumped temporarily or sporadically only until a clear view of the tissue is available to be imaged and recorded, at which point the fluid flow 28 may cease and blood 30 may be allowed to seep or flow back into imaging hood 12. This process may be repeated a number of times at the same tissue region or at multiple tissue regions.
In desirably positioning the assembly at various regions within the patient body, a number of articulation and manipulation controls may be utilized. For example, as shown in the articulatable imaging assembly 40 in
Additionally or alternatively, an articulatable delivery catheter 48, which may be articulated via one or more push-pull wires and having an imaging lumen and one or more working lumens, may be delivered through the deployment catheter 16 and into imaging hood 12. With a distal portion of articulatable delivery catheter 48 within imaging hood 12, the clear displacing fluid may be pumped through delivery catheter 48 or deployment catheter 16 to clear the field within imaging hood 12. As shown in
Alternatively, rather than passing an articulatable delivery catheter 48 through the deployment catheter 16, a distal portion of the deployment catheter 16 itself may comprise a distal end 49 which is articulatable within imaging hood 12, as shown in
Visualization within the imaging hood 12 may be accomplished through an imaging lumen 20 defined through deployment catheter 16, as described above. In such a configuration, visualization is available in a straight-line manner, i.e., images are generated from the field distally along a longitudinal axis defined by the deployment catheter 16. Alternatively or additionally, an articulatable imaging assembly having a pivotable support member 50 may be connected to, mounted to, or otherwise passed through deployment catheter 16 to provide for visualization off-axis relative to the longitudinal axis defined by deployment catheter 16, as shown in
If one or more optical fibers are utilized for imaging, the optical fibers 58 may be passed through deployment catheter 16, as shown in the cross-section of
To facilitate stabilization of the deployment catheter 16 during a procedure, one or more inflatable balloons or anchors 76 may be positioned along the length of catheter 16, as shown in
To further stabilize a position of the imaging hood 12 relative to a tissue surface to be imaged, various anchoring mechanisms may be optionally employed for temporarily holding the imaging hood 12 against the tissue. Such anchoring mechanisms may be particularly useful for imaging tissue which is subject to movement, e.g., when imaging tissue within the chambers of a beating heart. A tool delivery catheter 82 having at least one instrument lumen and an optional visualization lumen may be delivered through deployment catheter 16 and into an expanded imaging hood 12. As the imaging hood 12 is brought into contact against a tissue surface T to be examined, an anchoring mechanisms such as a helical tissue piercing device 84 may be passed through the tool delivery catheter 82, as shown in
The helical tissue engaging device 84 may be torqued from its proximal end outside the patient body to temporarily anchor itself into the underlying tissue surface T. Once embedded within the tissue T, the helical tissue engaging device 84 may be pulled proximally relative to deployment catheter 16 while the deployment catheter 16 and imaging hood 12 are pushed distally, as indicated by the arrows in
Although a helical anchor 84 is shown, this is intended to be illustrative and other types of temporary anchors may be utilized, e.g., hooked or barbed anchors, graspers, etc. Moreover, the tool delivery catheter 82 may be omitted entirely and the anchoring device may be delivered directly through a lumen defined through the deployment catheter 16.
In another variation where the tool delivery catheter 82 may be omitted entirely to temporarily anchor imaging hood 12,
An illustrative example is shown in
Optionally, processor 98 may also be utilized to coordinate the fluid flow and the image capture. For instance, processor 98 may be programmed to provide for fluid flow from reservoir 96 until the tissue area has been displaced of blood to obtain a clear image. Once the image has been determined to be sufficiently clear, either visually by a practitioner or by computer, an image of the tissue may be captured automatically by recorder 100 and pump 92 may be automatically stopped or slowed by processor 98 to cease the fluid flow into the patient. Other variations for fluid delivery and image capture are, of course, possible and the aforementioned configuration is intended only to be illustrative and not limiting.
Deployment of imaging hood 12 may be actuated by a hood deployment switch 120 located on the handle assembly 112 while dispensation of the fluid from reservoir 114 may be actuated by a fluid deployment switch 122, which can be electrically coupled to the controller 118. Controller 118 may also be electrically coupled to a wired or wireless antenna 124 optionally integrated with the handle assembly 112, as shown in the figure. The wireless antenna 124 can be used to wirelessly transmit images captured from the imaging hood 12 to a receiver, e.g., via Bluetooth® wireless technology (Bluetooth SIG, Inc., Bellevue, Wash.), RF, etc., for viewing on a monitor 128 or for recording for later viewing.
Articulation control of the deployment catheter 16, or a delivery catheter or sheath 14 through which the deployment catheter 16 may be delivered, may be accomplished by computer control, as described above, in which case an additional controller may be utilized with handle assembly 112. In the case of manual articulation, handle assembly 112 may incorporate one or more articulation controls 126 for manual manipulation of the position of deployment catheter 16. Handle assembly 112 may also define one or more instrument ports 130 through which a number of intravascular tools may be passed for tissue manipulation and treatment within imaging hood 12, as described further below. Furthermore, in certain procedures, fluid or debris may be sucked into imaging hood 12 for evacuation from the patient body by optionally fluidly coupling a suction pump 132 to handle assembly 112 or directly to deployment catheter 16.
As described above, fluid may be pumped continuously into imaging hood 12 to provide for clear viewing of the underlying tissue. Alternatively, fluid may be pumped temporarily or sporadically only until a clear view of the tissue is available to be imaged and recorded, at which point the fluid flow may cease and the blood may be allowed to seep or flow back into imaging hood 12.
The deployment catheter 16 may be then repositioned to an adjacent portion of mitral valve MV, as shown in
As mentioned above, when the imaging hood 12 is cleared by pumping the imaging fluid within for clearing the blood or other bodily fluid, the fluid may be pumped continuously to maintain the imaging fluid within the hood 12 at a positive pressure or it may be pumped under computer control for slowing or stopping the fluid flow into the hood 12 upon detection of various parameters or until a clear image of the underlying tissue is obtained. The control electronics 118 may also be programmed to coordinate the fluid flow into the imaging hood 12 with various physical parameters to maintain a clear image within imaging hood 12.
Detail examples and descriptions of a visualization catheter device and system which may be utilized herein are shown and described in further detail in U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005, which has been incorporated herein above in its entirety.
One particular application for the tissue visualization system includes utilizing the system for detecting the presence and/or location of ischemic and/or infarcted tissue by visual inspection and/or measurement of one or more parameter of the tissue. Any number of physiologic parameters can be utilized to obtain measurements of the visualized tissue to detect the certain parameters, e.g., partial pressure values of oxygen (PO2) and carbon dioxide (PCO2); temperature differences between tissue regions; biomarkers indicative of injured tissue; electrical current and/or electrical potential differences through the tissue; variations in tissue surface hardness and deflection between tissue regions; etc.
One method for detecting the ischemic and/or infarcted tissue is by visual inspection alone. As shown in the perspective view of
Another method for detecting certain tissue conditions may incorporate the use of fluorescent compounds injected into the tissue being visually inspected to enhance any contrasts in the tissue appearance. As shown in the respective side and perspective views of
The intensity and pattern of fluorescence may be observed directly by the user without image processing. Alternatively, imaging element 64 (which may be optionally filtered) may be in communication with signal processor 162 which may take the images and process them for analysis of the emitted wavelength distribution. The emitted wavelength distribution may be correlated to determine the physiologic characteristics of the tissue and the resulting image may be displayed upon a monitor 164 for user evaluation.
Another variation for determining tissue condition may include the use of a sensor probe 170 advanced into contact against the tissue surface T while under visualization from imaging element 64, as shown in
Aside from PO2 and PCO2 concentration measurement, sensor probe 170 may be additionally or alternatively configured to detect tissue temperature values as well. From local measured tissue temperatures as well as from the known temperature of the local perfusate, the user may extrapolate regions of the tissue T having relatively higher temperature values, which may be indicative of tissue having higher perfusion and metabolic activity (and presumably increased viability). Conversely, regions of tissue with relatively lower temperature values may be indicative of tissue having lower perfusion and metabolic activity (and presumably lowered viability), thus possibly indicating ischemic and/or infarcted tissue regions. The temperature measurements may also be processed 162 for visual representation 164, as illustrated by the temperature profile 174 as measured by probe 170.
The sensor probe(s) in
In yet another variation of
In another variation of
In yet another variation of
Once a region of ischemic and/or infarcted tissue has been identified using any of the modalities described above, the injured tissue may be repaired or improved, in one variation, by administering one or more bioactive substances into the affected tissue. One method for treating the injured tissue may utilize a hollow needle, such as piercing needle 160 shown above in
In yet another alternative for treating tissue regions identified as potentially ischemic and/or infarcted, a laser catheter may be utilized while under direct visualization of the tissue region of interest.
As the laser energy 212 is highly focused with intense energy to precisely ablate small quantities of tissue, the laser probe 210 may be used to perforate the tissue surface and/or deeper layers. Various bioactive chemicals may then be infused through hood 12 or through a catheter and directly into the tissue via the perforations. Alternatively, the tissue may be perforated during or after the various bioactive chemicals have been infused into the tissue. In yet another alternative, the tissue may be simply revascularized with the laser treatment and the infusion of bioactive chemicals may be omitted entirely, if so desired.
In yet another variation, a bioactive substance may be implanted into or near the injured tissue region. As shown in the partial cross-sectional view of the heart H, a bioactive substance 220 may be delivered and deposited directly into the tissue wall, e.g., in the anterolateral myocardium of the left ventricle, as shown in
In treating the tissue with bioactive substances, any number of suitable materials may be delivered utilizing the devices and methods herein. For instance, bioactive substances for healing and/or regenerating functional tissue may include the use of stem cells, which are protean cells from which other specialized cell lines are formed. Most damaged tissues undergo a natural process of death, resorption, and scar formation. If the stem cells, e.g., from a patient's bone marrow, can be identified and isolated these may be transplanted into the damaged tissue of interest. Ideally, the specific stem cell line responsible for generating the tissue of interest is identified and transplanted. Preclinical studies have established that implantation of bone marrow mononuclear into ischemic limbs increased collateral vessel formation. Direct myocardial injection of, e.g., bone marrow cells, into the infarct border zone produced improved LV function and infarct tissue perfusion (Tse, et al. Lancet 2003, Jan. 4; 361 (9357): 47-9), which is incorporated herein by reference in its entirety. It follows that by utilizing any of the previously described devices for direct visualization to identify the location of damaged tissue (e.g. infracted myocardium) and any of the delivery systems to deposit the bioactive substances, one may deliver bone marrow cells (e.g. vascular progenitor cells) to stimulate angiogenesis for improved tissue perfusion and function as well as new intrinsic tissue formation (e.g. myogenesis).
Another example of a bioactive substance which may be infused into the identified injured tissue may include biologic substances which promote angiogenesis and subsequently improve local tissue perfusion and function. Vascular endothelial growth factor (VEGF) is an angiogenic factor regulating vascular endothelial cell migration, proliferation, and permeability. Fibroblast growth factor (FGF) induces microvascular endothelial cell growth and neovascularization. Similarly, pro-angiogenic cytokines including tumor necrosis factor alpha (TNF) and interleukin 8 (IL8), as well as the peptides SIKVAV (derived from laminin 1) and neuropeptide Y (NPY) have been shown to demonstrate similar effects.
Aside from administering bioactive agents, chemical irritants may also be delivered to tissue utilizing any of the methods and systems described herein to promote angiogenesis and improved tissue perfusion and function.
The applications of the disclosed invention discussed above are not limited to certain treatments or regions of the body, but may include any number of other treatments and areas of the body. Modification of the above-described methods and devices for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the arts are intended to be within the scope of this disclosure. Moreover, various combinations of aspects between examples are also contemplated and are considered to be within the scope of this disclosure as well.
Claims
1. A method of identifying a tissue region of interest for treatment, comprising:
- positioning an expanded barrier or membrane defining an open area and projecting distally from a deployment catheter against the tissue region of interest;
- urging a transparent fluid into the open area such that an opaque fluid is displaced therefrom;
- visualizing the tissue region of interest through the transparent fluid; and
- assessing at least one parameter of the tissue region for an indication of injured tissue.
2. The method of claim 1 wherein positioning comprises intravascularly advancing the deployment catheter into a chamber of a patient heart.
3. The method of claim 1 wherein positioning comprises deploying the barrier or membrane from a low-profile delivery configuration into an expanded deployed configuration.
4. The method of claim 1 wherein urging a transparent fluid comprises pumping the transparent fluid into the open area through a fluid delivery lumen defined through the deployment catheter.
5. The method of claim 4 wherein pumping the transparent fluid comprises urging saline, plasma, water, or perfluorinated liquid into the open area such that blood is displaced.
6. The method of claim 1 wherein visualizing comprises imaging the tissue region via an imaging element off-axis relative to the deployment catheter.
7. The method of claim 1 wherein assessing comprises visually inspecting the tissue region for indications of ischemic and/or infarcted regions of tissue.
8. The method of claim 7 further comprising administering a fluorescent compound upon or into the tissue region prior to visually inspecting the tissue region.
9. The method of claim 8 wherein the fluorescent compound comprises indocyanin green.
10. The method of claim 1 wherein assessing comprises measuring a partial pressure of oxygen and/or carbon dioxide present in the tissue region.
11. The method of claim 1 wherein assessing comprises measuring a temperature of the tissue region.
12. The method of claim 1 wherein assessing comprises measuring for a presence of a biomarker indicative of tissue injury.
13. The method of claim 12 wherein the biomarker is selected from the group consisting of troponin T, troponin I, troponin C; creatine phosphokinase, MB fraction (CKMB), myoglobin, lactate dehydrogenase (LDH), and combinations thereof.
14. The method of claim 1 wherein assessing comprises detecting differences in electrical current and/or electrical potential in the tissue region.
15. The method of claim 1 wherein assessing comprises measuring relative tissue hardness and/or deflection over the tissue region.
16. The method of claim 1 further comprising identifying the injured tissue based upon an assessment of the at least one parameter.
17. The method of claim 16 further comprising treating the injured tissue with a bioactive agent.
18. The method of claim 17 wherein treating comprises injecting or infusing the bioactive agent upon or into the injured tissue.
19. The method of claim 17 wherein the bioactive agent is selected from the group consisting of stem cells, vascular endothelial growth factor, fibroblast growth factor, pro-angiogenic cytokines, tumor necrosis factor alpha, interleukin 8, SIKVAV, and neuropeptide Y.
20. The method of claim 16 further comprising treating the injured tissue with a chemical irritant.
21. A method of treating a tissue region of interest, comprising:
- positioning an expanded barrier or membrane defining an open area and projecting distally from a deployment catheter against the tissue region of interest;
- urging a transparent fluid into the open area such that an opaque fluid is displaced therefrom;
- visualizing the tissue region of interest through the transparent fluid;
- piercing at least partially into the tissue region with a delivery instrument; and
- delivering an agent through the instrument into the tissue region.
22. The method of claim 21 further comprising assessing at least one parameter of the tissue region for an indication of injured tissue.
23. The method of claim 22 wherein assessing comprises visually inspecting the tissue region for indications of ischemic and/or infarcted regions of tissue.
24. The method of claim 21 wherein positioning comprises deploying the barrier or membrane from a low-profile delivery configuration into an expanded deployed configuration.
25. The method of claim 21 wherein urging a transparent fluid comprises pumping the transparent fluid into the open area through a fluid delivery lumen defined through the deployment catheter.
26. The method of claim 25 wherein pumping the transparent fluid comprises urging saline, plasma, water, or perfluorinated liquid into the open area such that blood is displaced.
27. The method of claim 21 wherein visualizing comprises imaging the tissue region via an imaging element off-axis relative to the deployment catheter.
28. The method of claim 21 wherein the delivery instrument comprises a needle defining a lumen through which the agent is delivered.
29. The method of claim 21 wherein the delivery instrument comprises a helical needle having a plurality of openings therealong through which the agent may be delivered.
30. The method of claim 21 wherein delivering an agent comprises administering a fluorescent compound into the tissue region.
31. The method of claim 30 further comprising further visualizing the tissue region for an indication of injured tissue.
32. The method of claim 21 wherein delivering an agent comprises administering a bioactive agent into the tissue region.
33. The method of claim 32 wherein the bioactive agent is selected from the group consisting of stem cells, vascular endothelial growth factor, fibroblast growth factor, pro-angiogenic cytokines, tumor necrosis factor alpha, interleukin 8, SIKVAV, and neuropeptide Y.
34. The method of claim 21 wherein delivering an agent comprises administering a chemical irritant.
35. The method of claim 21 wherein delivering an agent comprises implanting an encapsulated bioactive substance.
36. A system for identifying a tissue region of interest, comprising:
- a deployment catheter defining at least one lumen therethrough;
- a barrier or membrane projecting distally from the deployment catheter and defining an open area therein, wherein the open area is in fluid communication with the at least one lumen;
- a visualization element disposed within or along the barrier or membrane for visualizing tissue adjacent to the open area; and
- a sensor probe configured to assess at least one parameter of the tissue region for an indication of injured tissue.
37. The system of claim 36 wherein the barrier is comprised of a compliant material.
38. The system of claim 36 wherein the barrier or membrane is adapted to be reconfigured from a low-profile delivery configuration to an expanded deployed configuration.
39. The system of claim 36 wherein the barrier or membrane is conically shaped.
40. The system of claim 36 wherein the visualization element comprises at least one optical fiber, CCD imager, or CMOS imager.
41. The system of claim 36 further comprising a fluorescent compound for injection or infusion upon or into the tissue region for facilitating imaging via the visualization element.
42. The system of claim 41 wherein the fluorescent compound comprises indocyanin green.
43. The system of claim 36 wherein the sensor probe is configured to measure a partial pressure of oxygen and/or carbon dioxide present in the tissue region.
44. The system of claim 36 wherein the sensor probe is configured to measure a temperature of the tissue region.
45. The system of claim 36 wherein the sensor probe is configured to measure for a presence of a biomarker indicative of tissue injury.
46. The system of claim 45 wherein the biomarker is selected from the group consisting of troponin T, troponin I, troponin C; creatine phosphokinase, MB fraction (CKMB), myoglobin, lactate dehydrogenase (LDH), and combinations thereof.
47. The system of claim 36 wherein the sensor probe is configured to detect differences in electrical current and/or electrical potential in the tissue region.
48. The system of claim 36 wherein the sensor probe is configured to measure relative tissue hardness and/or deflection over the tissue region.
49. The system of claim 36 further comprising a bioactive agent for injection or infusion upon or into the tissue region.
50. The system of claim 49 wherein the bioactive agent is selected from the group consisting of stem cells, vascular endothelial growth factor, fibroblast growth factor, pro-angiogenic cytokines, tumor necrosis factor alpha, interleukin 8, SIKVAV, and neuropeptide Y.
Type: Application
Filed: Jul 25, 2007
Publication Date: Jan 5, 2012
Patent Grant number: 8137333
Applicant: Voyage Medical, Inc. (Campbell, CA)
Inventors: Vahid SAADAT (Saratoga, CA), Sekhar Rao (Austin, TX)
Application Number: 11/828,267
International Classification: A61B 6/00 (20060101); A61M 31/00 (20060101);