In current surgical and diagnostic medical procedures, multiple types of imaging modalities are utilized to conduct the procedure. For example, a procedure may utilize both a fluoroscopic imaging device (obtaining images using x-ray radiation) and an ultrasound imaging device (obtaining images using sound waves). In each modality, different components can be more or less transparent depending upon the imaging modality. For example, internal tissue can be transparent to a fluoroscopic imaging device, yet visible with an ultrasound imaging device. In other instances, components can create artifacts that disrupt images that are obtained. For example, medical devices such as catheters can be readily observed with a fluoroscopic imaging device. However, such devices can create artifacts when imaged by an ultrasound imaging device.
Concepts presented herein relate to aligning imaging modalities. One concept relates to a method of controlling deployment of a prosthetic heart valve having a frame and opposed support arms connected to the frame. The method includes positioning an ultrasound imaging probe at a selected position with respect to a target site including a valve annulus. A probe orientation of the ultrasound imaging probe is sensed with respect to the target site at the selected position and a fluoroscopic imaging device is aligned to an aligned orientation with respect to the probe orientation such that an imaging plane for the ultrasound imaging probe is substantially perpendicular to an imaging plane for the fluoroscopic imaging device. An ultrasound image of the target site is obtained with the ultrasound imaging probe in the selected position. A fluoroscopic image of the target site is obtained with the fluoroscopic imaging device in the aligned orientation. The valve orientation and a valve position of the support arms with respect to the valve annulus are determined as a function of the ultrasound image and the fluoroscopic image.
Another concept relates to a system having a fluoroscopic imaging device mounted to a support head maintaining the fluoroscopic imaging device in a selected orientation. The system also includes an ultrasound imaging probe including an accelerometer measuring a probe orientation of the ultrasound imaging probe with respect to gravity. A processor is coupled to the accelerometer and provides a signal indicative of the probe orientation relative to the selected orientation.
In yet a further concept, a delivery device is disclosed for percutaneously deploying a stented prosthetic heart valve including a stent frame to which a valve structure is attached. The device includes a delivery sheath assembly terminating at a distal end and defining a lumen. The device further includes an inner shaft slideably disposed within a lumen and in contact with the stent frame. An accelerometer provides a signal indicative of an orientation of the stent frame with respect to gravity. The device is configured to provide a loaded state in which the delivery sheath assembly retains the stented prosthetic heart valve over the inner shaft and a deployment state in which the distal end of the delivery sheath assembly is withdrawn from the prosthetic heart valve to permit the prosthetic heart valve to release from the inner shaft assembly.
In yet a further concept, a delivery device for deploying an implantable medical device visible under fluoroscopy is provided. The delivery device includes a shaft assembly and an accelerometer coupled to the shaft assembly to provide a signal indicative of an orientation of the shaft assembly.
The fluoroscopic imaging device 12 and ultrasound imaging device 14 capture images with respect to a Cartesian coordinate system 20. As illustrated, the coordinate system 20 includes three orthogonal axes (denoted X, Y and Z axes), which define three orthogonal planes, namely an XY plane, an XZ plane and a YZ plane. In the embodiment illustrated, coordinate system 20 is coincident with gravity such that the Y axis is coaxial with the gravitational pull on system 10. In
As schematically illustrated in
In the embodiment illustrated in
System 10 further includes a delivery system 50 configured to deliver an implantable medical device 52 using a suitable catheter 54 to a target site. An accelerometer 56 is coupled with the catheter 54 to provide an indication of the orientation of the device 52 with respect to coordinate system 20. Device 52 and catheter 54 create artifacts when imaged by imaging probe 40, yet are discernable in images obtained by the fluoroscopic imaging device 12. To that end, in one embodiment, the device 52 and/or catheter 54 may include radiopaque material to enhance the visibility of the device 52 and/or catheter 54. Wiring 58 can be used to couple the accelerometer 56 to a suitable connection (wired or wireless) with computing system 16.
Further still, system 10 may include a contrast dye delivery system 60 having a catheter 62. Catheter 62 can deliver and inject a dye (e.g., a radiopaque dye) into a patient that is visible to the fluoroscopic imaging device 12. In particular, the catheter 62 includes a lumen with an outlet 64 in which dye exits from the catheter 62. The dye can be injected into a fluid stream such that the device 12 can determine flow of fluid within a patient.
Given components of system 10 above, one environment for which the system 10 is useful is in a procedure where a surgeon implants medical device 52 within a patient. In such a procedure, internal tissue of the patient can generally be visible with the ultrasound imaging probe 40. Moreover, the delivery system 50 and contrast dye delivery system 60 are visible to the fluoroscopic imaging device 12. The accelerometers 32, 44 and 56 can be utilized in order to align the fluoroscopic imaging device 12, the probe 40 and the implantable device 52 so as to properly implant the device 52 with respect to tissue within a patient. The accelerometers 32, 44 and 56 can take various forms, such as being embodied as single axis or triaxial accelerometer and can be formed of various components such as piezoelectric, piezoresistive and capacitive components.
Based on the orientation of probe 40 as calculated by the accelerometer 44, fluoroscopic imaging device 12 can be aligned with respect to the probe orientation at step 86, for example using support head 30 and accelerometer 32. In one embodiment, imaging device 12 is aligned such that the corresponding imaging plane 22 is orthogonal to imaging plane 24 of ultrasound probe 40. As such, a user can easily compare images from separate modalities (i.e., images from the fluoroscopic imaging device and the ultrasound imaging device) to evaluate the target site and correctly position the device 52 during implantation. In a further embodiment, fluoroscopic imaging device 12 can be aligned based on images obtained by the probe 40. For example, in one embodiment, the probe 40 can include an array that is substantially rectangular when viewed from a selected orientation. The device 12 can thus be oriented to produce a rectangular representation of probe 40. As such, this technique can be used to confirm a desired orientation of device 12. At step 88, one or more fluoroscopic images are obtained using the fluoroscopic imaging device 12. As such, tissue viewable by probe 40 and the device 52 viewable by imaging device 12 can be aligned with reference to images obtained using both probe 40 and imaging device 12. In one embodiment, device 12 can continuously provide images such that a surgeon can monitor the target site.
At step 90, the implantable device 52 is delivered to the target site using the delivery system 50. Once positioned at the target site, the orientation of the implantable device 52 can be determined at step 92 using accelerometer 56. Based on one or more of the images obtained from the ultrasound imaging probe and the fluoroscopic imaging device, the implantable device 52 can be implanted at step 94. Method 80 can be modified as desired. For example, the contrast dye delivery system 60 can inject dye one or more times during method 80 as desired. Additionally, the target site can be evaluated after implantation to confirm proper operation of the device 52.
With the above understanding of aligning imaging modalities in mind, the concepts presented herein can be applied in various situations when aligning one or more medical devices with tissue internal to a patient. For example, a catheter delivered occluder that blocks a hole in a wall of a heart can be used within the system 10 of
As referred to herein, stented transcatheter prosthetic heart valves useful with and/or as part of the various systems, devices, and methods of the present disclosure may assume a wide variety of different configurations, such as a bioprosthetic heart valve having tissue leaflets or a synthetic heart valve having polymeric, metallic, or tissue-engineered leaflets, and can be specifically configured for replacing any heart valve. Thus, the stented prosthetic heart valve useful with the systems, devices, and methods of the present disclosure can be generally used for replacement of a native aortic, mitral, pulmonic, or tricuspid valve, for use as a venous valve, or to replace a failed bioprosthesis, such as in the area of an aortic valve or mitral valve, for example.
With the above understanding in mind, one non-limiting example of a stented prosthetic heart valve 100 useful with systems and methods of the present disclosure is illustrated in
The stent frame 102 is generally constructed so as to be self-expandable from the compressed arrangement (
Given the components of the prosthetic heart valve 100, the valve can be defined to include an inflow section 110 (receiving fluid) and an outflow section 112 (forcing out fluid). Moreover, the stent frame 102 defines a central axis 114 extending in a direction from the inflow section 110 to the outflow section 112 and a support arm axis 116 delineating an orientation of the support arms 108.
With the but one acceptable construction of
Given the above description of the stented prosthetic heart valve 100, one embodiment of delivery system 50 for repairing a defective heart valve is shown in
In general terms, the system 50 is transitionable from a loaded or delivery condition (shown in
Components in accordance with some embodiments of the delivery device 140 are shown in greater detail in
In some embodiments, the delivery sheath assembly 142 includes the capsule 150 and a shaft 160, and defines a lumen 162 (referenced generally) extending from a distal end 164 to a proximal end 166. In some constructions, the capsule 150 and the shaft 160 are comprised of differing materials and/or constructions, with the capsule 150 having a longitudinal length approximating (e.g., slightly greater than) a length of the prosthetic heart valve 100 (
Regardless, the capsule 150 is constructed to compressively retain the stented prosthetic heart valve 100 at a predetermined diameter when loaded within the capsule 150, and the shaft 160 serves to connect the capsule 150 with the handle 148. To better accommodate a size of the compressed prosthesis 100 while at the same time maintaining an overall low profile, an outer diameter of the capsule 150 can be greater than an outer diameter of the shaft 160 in some embodiments, with the resultant construction providing the capsule 150 with a discernable proximal end 170. The shaft 160 (as well as the capsule 150) is constructed to be sufficiently flexible for passage through a patient's vasculature, yet exhibits sufficient longitudinal rigidity to effectuate desired axial movement of the capsule 150. In other words, proximal retraction of the shaft 160 is directly transferred to the capsule 150 and causes a corresponding proximal retraction of the capsule 150. In other embodiments, the shaft 160 is further configured to transmit a rotational force or movement onto the capsule 150.
The inner shaft assembly 144 can have various constructions appropriate for supporting a stented prosthetic heart valve within the capsule 150. For example, the inner shaft assembly 144 can include a retention member 180, an intermediate tube 182, and a proximal tube 184. In general terms, the retention member 180 is akin to a plunger, and incorporates features for retaining the stented prosthetic heart valve 100 (
The retention member 180 can include a tip 190, a support tube 192, and a hub 194. The tip 190 forms or defines a nose cone having a distally tapering outer surface adapted to promote atraumatic contact with bodily tissue. The tip 190 can be fixed or slidable relative to the support tube 192. The support tube 192 extends proximally from the tip 190 and is configured to internally support a compressed, stented prosthetic heart valve generally disposed thereover, and has a length and outer diameter corresponding with dimensional attributes of the prosthetic heart valve. The hub 194 is attached to the support tube 192 opposite the tip 190 (e.g., adhesive bond) and provides a coupling structure 196 (referenced generally) configured to selectively capture a corresponding feature of the prosthetic heart valve.
The coupling structure 196 can assume various forms, and is generally located along an intermediate portion of the inner shaft assembly 144. In some embodiments, the coupling structure 196 includes one or more fingers sized to be slidably received within corresponding apertures formed by the prosthetic heart valve stent frame 102 (
The intermediate tube 182 is formed of a flexible material (e.g., PEEK), and is sized to be slidably received within the delivery sheath assembly 142 and in particular the shaft 160. The proximal tube 184 can include a leading portion 200 and a trailing portion 202. The leading portion 200 serves as a transition between the intermediate and proximal tubes 182, 184, and thus can be a flexible tubing (e.g., PEEK) having a diameter slightly less than that of the intermediate tube 182. The trailing portion 202 has a more rigid construction, configured for robust assembly with the handle 148. For example, the trailing portion 202 can be a metal hypotube, although other constructions are also acceptable. In yet other embodiments, the intermediate and proximal tubes 182, 184 are integrally formed as a single, homogenous tube or solid shaft.
The stability tube 146 includes or defines the distal region 152 and a proximal region 210. The stability tube 146 forms a lumen 212 (referenced generally) sized to be slidably received over the delivery sheath assembly 142 as described below, with the stability tube 146 terminating at a distal end 214.
The proximal region 210 connects the distal region 152 with the handle 148. With this construction, the stability tube 146 serves as a stability shaft for the delivery sheath assembly 142, and has a length selected to extend over a significant (e.g., at least a majority), and in some embodiments at least 80%, of a length of the delivery sheath assembly 142 in distal extension from the handle 148. Further, the stability tube 146 exhibits sufficient radial flexibility to accommodate passage through a patient's vasculature (e.g., the femoral artery and the aortic arch).
The handle 148 generally includes a housing 230 and one or more actuator mechanism 232 (referenced generally). The housing 230 maintains the actuator mechanism 232, with the handle 148 configured to facilitate sliding movement of the delivery sheath assembly 142 relative to the inner shaft assembly 144 and the stability tube 146. The housing 230 can have any shape or size appropriate for convenient handling by a user. In one simplified construction of the actuator mechanism 232, a user interface or actuator 234 is slidably retained by the housing 230 and coupled to a connector body 236. The inner shaft assembly 144, and in particular the proximal tube 184 is slidably received within a passage 238 (referenced generally) of the connector body 236 and is rigidly coupled to the housing 230. With this but one acceptable construction, the deployment actuator 234 can be operated by a user to effectuate axial or longitudinal movement of the delivery sheath assembly 142 relative to the inner shaft assembly 144 and the stability tube 146. In some embodiments, the housing 230 can further incorporate a second actuator mechanism (not shown) that facilitates user-actuated movement of the stability tube 146 relative to the delivery sheath assembly 142. Further, the handle 148 can include other features, such as optional port assemblies 242, a cap 244, and/or a manifold 246 as shown.
Delivery system 50 and valve 100 are useful in replacing a native mitral valve of a patient. In one embodiment, replacement of a native mitral valve includes capturing native leaflets and deploying the valve within the mitral valve annulus.
The four valves work by opening and closing in harmony with each other. During diastole, tricuspid valve 314 and mitral valve 316 open and allow blood flow into ventricles 326 and 322, and the pulmonic valve and aortic valve are closed. During systole, aortic valve 318 and pulmonary valve 322 open and allow blood flow from left ventricles 324 and right ventricle 326 into aorta 322 and pulmonary artery 320, respectively.
As illustrated in
Using accelerometer 44, an orientation of the probe 40 can be determined with respect to gravity, thus providing an indication of the orientation of imaging plane 24. Based on the probe orientation, the fluoroscopic imaging device 12 can be aligned using accelerometer 30 such that imaging plane 22 and imaging plane 24 are orthogonal to one another. With the imaging planes 22 and 24 in a desired alignment, images obtained with fluoroscopic imaging device 12 can be directly comparable with images obtained with probe 40. Using accelerometer 56, a device orientation is obtained and can be adjusted for implantation of valve 100. In particular, support arm axis 116 can be oriented to also be orthogonal to imaging plane 24, such that leaflets 302 and 304 can be captured.
In
Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present disclosure.