Patent Application
20150173629
Embodiments of the present disclosure relate generally to the field of medical devices and, more particularly, to a device, system, and method for assessing pressure within vessels. In particular, the present disclosure relates to the assessment of the severity of a blockage or other restriction to the flow of fluid through a vessel. Aspects of the present disclosure are particularly suited for evaluation of biological vessels in some instances. For example, some particular embodiments of the present disclosure are specifically configured for the evaluation of a stenosis of a human blood vessel.
Heart disease is a serious health condition affecting millions of people worldwide. One major cause of heart disease is the presence of blockages or lesions within the blood vessels that reduce blood flow through the vessels. Traditionally, interventional cardiologists have relied on X-ray fluoroscopic images with injection of X-ray contrast medium into the artery of interest to highlight the silhouette of the vessel lumen to guide treatment. Unfortunately, the limited resolution and discrete projections provided by X-ray fluoroscopy often yield insufficient information to accurately assess the functional significance (i.e., impairment of blood flow) attributable to an obstruction.
Improved techniques for assessing the functional significance and likely benefit of treatment of a stenosis in a blood vessel are the calculation of fractional flow reserve (FFR) and instantaneous wave-free ratios. FFR is defined as the ratio of the maximal hyperemic blood flow in a stenotic artery compared to what the maximal flow would be if the stenosis were alleviated. Instantaneous wave-free ratio is defined as the ratio of blood flow in a stenotic artery distal to the stenosis during the wave-free period of diastole compared to the aortic pressure. Both FFR and the instantenous wave-free ratio values are calculated as the ratio of the distal (to the stenosis) pressure to the proximal (typically aortic) pressure, sometimes also including a small correction to account for the effect of the venous pressure. Both FFR and the instantaneous wave-free ratio provide an index of stenosis severity that allow determination if the obstruction limits blood flow within the vessel to an extent that intervention is warranted, taking into consideration both the risks and benefits of treatment. The more restrictive the stenosis, the greater the pressure drop across the stenosis, and the lower the resulting FFR or instantaneous wave-free ratio. Both FFR and instantaneous wave-free ratio measurements can be used to establish a criterion for guiding treatment decisions. The ratio in a healthy vessel is by definition 1.00. FFR values less than about 0.80 are generally deemed to indicate a functionally significant lesion likely to benefit from treatment, while values above 0.80 indicate reduced likelihood of net benefit from intervention. Instantaneous wave-free ratio values have been correlated to FFR values whereby a value of 0.89 approximates an FFR of 0.80. Common treatment options include angioplasty or atherectomy with stent implantation, or surgical bypass of the obstructed artery.
One method for measuring the proximal and distal pressures used for FFR calculation is to advance a pressure sensing guidewire (with a pressure sensor embedded near its distal tip) across the lesion to a distal location, while the guiding catheter (with an attached pressure transducer) is used to provide a pressure measurement proximal to the stenosis (typically in the aorta or the ostium of the coronary artery). Despite the level of evidence in the guidelines, the use of pressure sensing guide wires remains relatively low (estimated less than 6% of cases worldwide). The reasons are partially tied to the performance of the pressure guide wires relative to that of standard angioplasty wires. Incorporating a pressure sensor into a guidewire generally requires compromises in the mechanical performance of the guidewire in terms of steerability, durability, stiffness profile, etc., that make it more difficult to navigate the coronary circulation to deliver the guidewire or subsequent interventional catheters across the lesion. As such, physicians will often abandon use of a pressure sensing guidewire when they experience challenges steering the pressure guide wire distal to the disease. And it is common where a physician may not even try a pressure guide wire, despite a desire to do so, because the anatomy appears visually as too challenging. Efforts continue to design pressure guide wires to perform more like standard angioplasty wires, but there are inherent design limitations that prevent that from happening.
Another method of measuring the pressure gradient across a lesion is to use a small catheter connected to an external blood pressure transducer to measure the pressure at the tip of the catheter through a fluid column within the catheter, similarly to the guiding catheter pressure measurement. However, this method can introduce error into the FFR calculation because as the catheter crosses the lesion, it creates additional obstruction to blood flow across the stenosis and contributes to a lower distal blood pressure measurement than what would be caused by the lesion alone, exaggerating the apparent functional significance of the lesion.
While the existing treatments have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects. The devices, systems, and associated methods of the present disclosure overcome one or more of the shortcomings of the prior art.
In one exemplary embodiment, the present disclosure describes an apparatus for intravascular pressure measurement, comprising: an elongate body including a proximal portion and a distal portion, the body defining a lumen extending from a proximal end to a distal end of the body, the lumen sized and shaped to allow the passage of a guidewire there through, the body including an annular wall extending from the lumen to an outer surface of the body; and a first pressure sensor disposed within the wall of the distal portion of the body, the pressure sensor including a sensor cover coupled to the wall, wherein an exterior surface of the sensor cover and the outer surface of the body are substantially aligned. The apparatus can include at least one perfusion port in the wall that enables fluid communication between the lumen and environmental contents outside the elongate body. The at least one perfusion port can include an aperture extending through the wall from the outer surface of the body to the lumen.
In another exemplary embodiment, the present disclosure describes a method for intravascular pressure measurement within a lumen of a vessel including a lesion, comprising: positioning a guidewire within the lumen of the vessel distal to the lesion; advancing a pressure-sensing catheter including a first pressure sensor and at least one perfusion port over the guidewire within the lumen of the vessel such that the first pressure sensor is positioned distal to the lesion; withdrawing the guidewire in a proximal direction until the guidewire is positioned proximal of the at least one perfusion port; and obtaining a distal pressure measurement from the first pressure sensor. The method can also include imaging the pressure-sensing catheter to obtain image data reflecting the location of the first pressure sensor within the lumen relative to the lesion and repositioning the pressure-sensing catheter in an optimal intravascular location for pressure measurement based on the image data. The method can also include withdrawing the pressure-sensing catheter in a proximal direction to position the first pressure sensor proximal to the lesion, withdrawing the guidewire in a proximal direction until the guidewire is positioned proximal of both the lesion and the at least one perfusion port, and obtaining a proximal pressure measurement from the first pressure sensor.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description.
The accompanying drawings illustrate embodiments of the devices and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. In addition, dimensions provided herein are for specific examples and it is contemplated that different sizes, dimensions, and/or ratios may be utilized to implement the concepts of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.
The present disclosure relates generally to a device, systems, and methods of using a pressure-sensing catheter for the assessment of intravascular pressure, including, by way of non-limiting example, the calculation of an FFR value. These measurements can also be made in the peripheral vasculature including but not limited to the Superficial femoral artery (SFA), below the knee (BTK, i.e. Tibial), and Iliac artery. In some instances, embodiments of the present disclosure are configured to measure the pressure proximal to and distal to a stenotic lesion within a blood vessel. Embodiments of the present disclosure include a pressure sensor embedded in the wall of the catheter instead of being encased in a bulky housing attached to the catheter. In some embodiments, the pressure-sensing catheter disclosed herein includes at least one perfusion port extending through the catheter wall to allow for blood flow through the catheter lumen. In some embodiments, the pressure-sensing catheter disclosed herein is configured as a rapid exchange catheter. In other embodiments, the pressure-sensing catheter disclosed herein is configured as a conventional over-the-wire catheter. The pressure-sensing catheters disclosed herein enable the user to obtain pressure measurements using an existing guidewire (e.g., a conventional 0.014 inch guidewire) that can remain fairly stationary through the pressure measurement procedure. Thus, the pressure-sensing catheters disclosed herein enable the user to obtain physiologic information about an intravascular lesion upon pullback of the catheter without losing the original position of the guidewire.
In particular, the body 220 is shaped and configured for insertion into a lumen of a blood vessel (not shown) such that a longitudinal axis CA of the catheter 100 aligns with a longitudinal axis of the vessel at any given position within the vessel lumen. In that regard, the straight configuration illustrated in
The body 220 extends from an adapter 230 along the longitudinal axis CA. In the pictured embodiment, the body 220 is integrally coupled to the adapter 230. In other embodiments, the body 220 may be detachably coupled to the adapter 230, thereby permitting the body 220 to be replaceable. The adapter 230 is configured to couple the catheter 200 to another medical device through a port 232 and/or an electrical connection 245. The port 232 may be configured to receive fluid there through, thereby permitting the user to irrigate or flush the lumen 225. Various medical devices that may be coupled to the catheter 200 include, by way of non-limiting example, a storage vessel, a disposal vessel, a vacuum system, a syringe, an infusion pump, and/or an insufflation device. For example, the port 232 may include a Luer-type connector capable of sealably engaging an irrigation device such as a syringe. Various devices that may be coupled to the catheter 200 by the electrical connection 245 include, by way of non-limiting example, an energy generator (e.g., an ultrasound generator), a power source, a patient interface module (“PIM”), a computer system, and/or a surgical console. In the pictured embodiment, the adapter 230 couples the body 220 to an interface 240 by the electrical connection 245.
The body 220 includes a proximal portion 250, and intermediate portion 255, and a distal portion 260. The proximal portion 250 of the body 220 connects to the adapter 230, which may be sized and configured to be held and manipulated by a user outside a patient's body. By manipulating the adapter 230 outside the patient's body, the user may advance the body 220 of the catheter 210 through an intravascular path and remotely manipulate or actuate the distal portion 260 holding the sensor 300. The lumen 225 allows for the passage of contents from the distal portion 260 to the proximal portion 250, and in some instances through the adapter 230. The lumen 225 is shaped and configured to allow the passage of fluid, cellular material, or another medical device from a proximal end 246 to a distal end 247 (and/or a guidewire port 265). In some embodiments, the lumen 225 is sized to accommodate the passage of a guidewire. In such an embodiment, the lumen 225 has an internal diameter greater than 0.014 inches. In some embodiments, the body 220 includes more than one lumen.
In
In the pictured embodiment, the proximal portion 250 of the catheter 210 includes shaft markers 262 to aid in positioning the catheter 210 in the body of a patient. The shaft markers 262 may be visible to the naked eye. In some embodiments, the shaft markers 262 may indicate the relevant insertion distance from a particular anatomical entry point, such as the radial artery and/or the femoral artery.
The intermediate portion 255 may include the guidewire port 265 from which a guidewire may enter or emerge. In other embodiments, the guidewire port 265 may be disposed elsewhere on the catheter 210. Other embodiments may lack a guidewire port 265. The guidewire port 265 may be formed at a variety of distances along the elongated body 220. In some embodiments the distance between the guidewire port 265 and the distal end 247 ranges from about 10 cm to about 20 cm. For example, in one embodiment the distance between the guidewire port 265 and the distal end 247 ranges from about 10 cm to about 12 cm. These examples are provided for illustrative purposes only, and are not intended to be limiting.
In the pictured embodiment, the distal portion 260 includes several radiopaque markers 270. Each radiopaque marker 270 may be coupled to the catheter wall 222 at a known distance from the pressure sensor 300 and/or the distal end 247. The radiopaque markers 270 permit the physician to fluoroscopically visualize the location and orientation of the markers, the distal end 247, and the pressure sensor 300 within the patient. For example, when the distal portion 260 extends into a blood vessel in the vicinity of a lesion, X-ray imaging of the radiopaque markers 270 may confirm successful positioning of the pressure sensor 300 distal to or proximal to the lesion. In some embodiments, the radiopaque markers 270 may circumferentially surround the body 220. In other embodiments, the radiopaque markers 270 may be shaped and configured in any of a variety of suitable shapes, including, by way of non-limiting example, rectangular, triangular, ovoid, linear, and non-circumferential shapes. The radiopaque markers 270 may be formed of any of a variety of biocompatible radiopaque materials that are sufficiently visible under fluoroscopy to assist in the procedure. Such radiopaque materials may be fabricated from, by way of non-limiting example, platinum, gold, silver, platinum/iridium alloy, and tungsten. The markers 270 may be attached to the catheter 200 using a variety of known methods such as adhesive bonding, lamination between two layers of polymers, or vapor deposition, for example. Various embodiments may include any number and arrangement of radiopaque markers. In some embodiments, the catheter 200 lacks radiopaque markers.
In the pictured embodiment, the distal portion 260 includes an imaging apparatus 280. The imaging apparatus 280 may comprise any type of imaging apparatus that is configured for use in intravascular imaging, including without limitation intravascular ultrasound imaging (IVUS) and optical coherence tomography (OCT). Other embodiments may lack the imaging apparatus 280.
The distal portion 260 of the catheter 210 includes a pressure sensor 300 positioned at a distal tip 290. In some embodiments, the distal tip 290 is tapered to facilitate insertion of the body 220 into a patient. In other embodiments, the distal tip 290 may be blunt, angled, or rounded. The pressure sensor 300 is embedded within the catheter wall 222 of the catheter 210. In the pictured embodiment, the pressure sensor 300 is located within the distal portion 260 and is proximal to the distal tip 290. The pressure sensor 300 will be described in further detail below in relation to
As mentioned above, the interface 240 is configured to connect the catheter 210 to a patient interface module or controller 310, which may include a guided user interface (GUI) 315. More specifically, in some instances the interface 240 is configured to communicatively connect at least the pressure sensor 300 of the catheter 210 to the controller 310 suitable for carrying out intravascular pressure measurement. In some instances the interface 240 is configured to communicatively connect the imaging apparatus 280 to a controller 310 suitable for carrying out intravascular imaging. The controller 310 is in communication with and performs specific user-directed control functions targeted to a specific device or component of the system 200, such as the pressure sensor 300 and/or the imaging apparatus 280.
The interface 240 may also be configured to include at least one electrical connection electrically coupled to the pressure sensor 300 via a dedicated sensor cable (not shown in
The controller 310 may be connected to the processor 320, which is typically an integrated circuit with power, input, and output pins capable of performing logic functions. The processor 320 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or equivalent discrete or integrated logic circuitry. In some examples, processor 320 may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to processor 320 herein may be embodied as software, firmware, hardware or any combination thereof.
In various embodiments, the processor 320 is a targeted device controller that may be connected to a power source 325, accessory devices 340, and/or a memory 345. In such a case, the processor 320 is in communication with and performs specific control functions targeted to a specific device or component of the system 200, such as the pressure sensor 300 and/or the imaging apparatus 280, without utilizing user input from the controller 310. For example, the processor 320 may direct or program the expandable structure 300 to function for a period of time without specific user input to the controller 310. In some embodiments, the processor 320 is programmable so that it can function to simultaneously control and communicate with more than one component of the system 200, including the accessory devices 340, the memory 345, and/or the power source 325. In other embodiments, the system includes more than one processor and each processor is a special purpose controller configured to control individual components of the system.
The processor 320 may include one or more programmable processor units running programmable code instructions for implementing the pressure measurement methods described herein, among other functions. The processor 320 may be integrated within a computer and/or other types of processor-based devices suitable for a variety of intravascular applications, including, by way of non-limiting example, pressure sensing and/or intravascular imaging. The processor 320 can receive input data from the controller 310, from the imaging apparatus 280 and/or the pressure sensor 300 directly via wireless mechanisms, or from the accessory devices 340. The processor 320 may use such input data to generate control signals to control or direct the operation of the catheter 210. In some embodiments, the user can program or direct the operation of the catheter 210 and/or the accessory devices 340 from the controller 310 and/or the GUI 315. In some embodiments, the processor 320 is in direct wireless communication with the imaging apparatus 280 and/or the pressure sensor 300, and can receive data from and send commands to the imaging apparatus 280 and/or the pressure sensor 300.
The power source 325 may be a rechargeable battery, such as a lithium ion or lithium polymer battery, although other types of batteries may be employed. In other embodiments, any other type of power cell is appropriate for power source 325. The power source 325 provides power to the system 200, and more particularly to the processor 320 and the pressure sensor 300. The power source 325 may be an external supply of energy received through an electrical outlet. In some examples, sufficient power is provided through on-board batteries and/or wireless powering.
The various peripheral devices 340 may enable or improve input/output functionality of the processor 320. Such peripheral devices 340 include, but are not necessarily limited to, standard input devices (such as a mouse, joystick, keyboard, etc.), standard output devices (such as a printer, speakers, a projector, graphical display screens, etc.), a CD-ROM drive, a flash drive, a network connection, and electrical connections between the processor 320 and other components of the system 200. By way of non-limiting example, the processor 320 may manipulate data from the pressure sensor 300 to generate a pressure ratio (i.e. FFR) value, evaluate the severity of the lesion or stenosis, and may suggest an appropriate treatment for the patient based on the pressure ratio and/or the flow data. The peripheral devices 340 may also be used for downloading software containing processor instructions to enable general operation of the catheter 210, and for downloading software implemented programs to perform operations to control, for example, the operation of any auxiliary devices attached to the catheter 210. In some embodiments, the processor may include a plurality of processing units employed in a wide range of centralized or remotely distributed data processing schemes.
The memory 345 is typically a semiconductor memory such as, for example, read-only memory, a random access memory, a FRAM, or a NAND flash memory. The memory 345 interfaces with processor 320 such that the processor 320 can write to and read from the memory 345. For example, the processor 320 can be configured to read data from the pressure sensor 300, calculate pressure ratios (i.e. FFR) from that data, and write that data and the calculated ratios to the memory 345. In this manner, a series of pressure readings and/or calculated pressure ratios can be stored in the memory 345. The processor 320 is also capable of performing other basic memory functions, such as erasing or overwriting the memory 345, detecting when the memory 345 is full, and other common functions associated with managing semiconductor memory.
The controller 310 may be configured to couple the pressure sensor 300 to the processor 320. In some embodiments, under the user-directed operation of the controller 310, the processor 320 may generate a selected sequence or frequency of pressure readings best suited to a particular application. As described above, in some embodiments, at least one sensor wire (not shown in
In the pictured embodiment, the sensor 300 is positioned within a sensor recess 410 within the catheter wall 222. In some embodiments, the sensor 300 is in intimate contact with the wall 222. The sensor 300 may be coupled to the catheter wall 222 using any of a variety of known connection methods, including by way of non-limiting example, welding, biologically-compatible adhesive, and/or mechanical fasteners. For example, in one embodiment, the sensor 300 is adhesively bonded to the sensor recess 410 using Loctite 3311 or any other biologically compatible adhesive. In some embodiments, the sensors may be integrally formed with the catheter wall 222. In some embodiments (e.g.,
A communication channel 415 extends proximally from the sensor recess 410 toward the adapter 230 (shown in
The sensor 300 is sealed within the wall 222 by a sensor cover 425. The sensor cover 425 isolates and protects the sensor 300 from the environment surrounding the catheter 210. The sensor cover 425 may be formed of any of a variety of suitable biocompatible materials, such as, by way of non-limiting example, silicone, polymer, pebax, nylon, PTFE, polyurethane, PET, and/or combinations thereof. The sensor cover 425 is shaped to lie flush with the catheter wall 222. In other words, an outer surface 430 of the catheter 210 and an exterior surface 431 of the sensor cover 425 are substantially aligned so that the outer diameter D2 of the catheter 210 remains substantially unchanged in the area of the sensor 300 compared to the remainder of the catheter 210. The outer surface 430 of the catheter 210 and/or the exterior surface 431 of the sensor cover 425 may be coated with a hydrophilic or hydrophobic coating.
Other catheter embodiments may include a variety of other sensors embedded within or associated with the wall 222. As a result, the catheter 210 may be capable of simultaneously examining a number of different characteristics of the target tissue, the surrounding environment, and/or the catheter 210 itself within the body of a patient, including, for example, vessel wall temperature, blood temperature, electrode temperature, fluorescence, luminescence, and flow rate, in addition to pressure.
The lumen 225 includes an internal diameter D1 that is sized and shaped to accommodate the passage of the guidewire 400. The internal diameter D1 may range from 0.014 in. to 0.035 in. In one embodiment, the internal diameter D1 is 0.016 in. In one embodiment, the internal diameter D1 is 0.024 in. In one embodiment, the internal diameter D1 is 0.014 in. In another embodiment, the internal diameter D1 is 0.035 in. The catheter 210 includes an outer diameter D2 that is sized and shaped to traverse bodily passageways. In the pictured embodiment, the outer diameter is sized to allow passage of the catheter through vascular passageways. In some instances, as mentioned above, the body 220 has an external diameter D2 ranging from 0.014 inches to 0.040 inches. In one embodiment, the outer diameter D2 is 0.024 in. In one embodiment, the outer diameter D2 is 0.018 in. In another embodiment, the outer diameter D2 is 0.035 in.
As shown in
In the pictured embodiment, the catheter 210 includes two radiopaque markers 270 that flank the sensor 300. Image guidance using the imaging apparatus 280 (shown in
As described above, in the pictured embodiment, the catheter 210 can include shaft markers 262 disposed along the proximal portion 250 of the catheter 210 to aid in positioning the catheter in the body of a patient. The shaft markers 262 may be positioned a specific distance from each other and comprise a measurement scale reflecting the distance of the marker 262 from the sensor 300 and/or the distal end 247. The proximal portion 250 may include any number of shaft markers 262 positioned a fixed distance away from the sensor 300 associated with a range of expected distances from the patient's skin surface at the point of catheter entry to the desired area of pressure measurement and/or other intervention. In the pictured embodiment, a shaft marker 262a is positioned approximately 10 cm from a shaft marker 262b. Shaft marker 262a is positioned approximately 90 cm from the sensor 300 to reflect a standard distance of advancement from a radial access point, and the shaft marker 262a is positioned approximately 100 cm from the sensor 300 to reflect a standard distance of advancement from a femoral access point. Additional shaft markers 262 may be marked on the catheter 210 to indicate more lengths and distances.
After initially positioning the sensor 300 within the target vessel, the user may utilize the shaft markers 262 to knowledgeably shift or reposition the catheter 210 along the intravascular target vessel to measure pressure at desired locations (e.g., relative to any lesions) and/or intervals along the target vessel before, after, or without employing imaging guidance. By noting the measurement and/or change in measured distance indicated by the shaft markers 262 located immediately external to the patient's body as the catheter 210 is shifted, the user may determine the approximate distance and axial direction the sensor 300 has shifted within the patient's vasculature. In addition, the user may use the measurement and/or change in measured distance indicated by the shaft markers located immediately external to the patient's body to cross reference the intravascular position of the pressure sensor 300 indicated by intravascular imaging. In some embodiments, the shaft markers 262 may be radiopaque or otherwise visible to imaging guidance. Other embodiments may lack shaft markers.
The pressure-sensing catheters described herein may include any number and arrangement of perfusion ports, and the perfusion ports may be of varied shapes and sizes. For example, in some embodiments, the catheter may include only one perfusion port such as the perfusion port 505 in catheter 500. In other embodiments, the pressure-sensing catheter may include no perfusion ports, as described above with respect to catheter 210 in
The vessel V includes a lumen 805 that includes a circumferential lesion 810. The lumen 805 includes a luminal wall 815 that is irregularly shaped by the presence of the lesion 810 (e.g., an atherosclerotic plaque). Blood flows through the lumen 805 in the direction of the arrows 820. Prior to insertion of the catheter 800, the guidewire 400 may be introduced into the vasculature of a patient using standard percutaneous techniques. Once the guidewire 400 is positioned within the target blood vessel, the catheter 800 may be introduced into the vasculature of a patient over the guidewire 400 and advanced to the area of interest. In the alternative, the catheter 800 may be coupled to the guidewire 400 external to the patient and both the guidewire 460 and the catheter 800 may be introduced into the patient and advanced to an area of interest simultaneously.
The user can advance the catheter 800 over the guidewire 400 until the sensor 300 is positioned distal to or downstream of the lesion 810. The user may use radiopaque markings (e.g., radiopaque markers 270 and/or a radiopaque sensor recess 420) and/or shaft markers (e.g., shaft markers 262) on the catheter 800 to verify the desired positioning of the catheter 800 relative to the lesion. The catheter 800 may include IVUS or other imaging apparatuses 280 (as shown in
As shown in
Prior to insertion of the catheter 900, the guidewire 400 may be introduced into the vasculature of a patient using standard percutaneous techniques. Once the guidewire 400 is positioned within the target blood vessel, the catheter 900 may be introduced into the vasculature of a patient over the guidewire 400 and advanced to the area of interest. In the alternative, the catheter 900 may be coupled to the guidewire 400 external to the patient and both the guidewire 460 and the catheter 900 may be introduced into the patient and advanced to an area of interest simultaneously.
The user can advance the catheter 900 over the guidewire 400 until the sensor 300a is positioned distal to or downstream of the lesion 810 and the sensor 300b is positioned proximal to or upstream of the lesion 810. The user may use radiopaque markings (e.g., radiopaque markers 270 and/or a radiopaque sensor recess 420) and/or shaft markers (e.g., shaft markers 262) on the catheter 900 to verify the desired positioning of the catheter 900 relative to the lesion. The catheter 900 may include IVUS or other imaging apparatuses 280 (as shown in
As shown in
Persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. For example, the pressure-sensing catheters disclosed herein may be utilized anywhere with a patient's body, including both arterial and venous vessels, having an indication for pressure measurement. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.
The present application claims priority to and the benefit of the U.S. Provisional Patent Application No. 61/918,601, filed Dec. 19, 2013, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61918601 | Dec 2013 | US |
