Patent Publication Number: US-2012041534-A1

Title: Stent delivery system with integrated camera

Description:
This application claims the benefit of U.S. Provisional Application No. 61/372,277, entitled “STENT DELIVERY SYSTEM WITH INTEGRATED CAMERA,” by Claude Clerc, Chris Benning, Bill Bertilino, John Lane, John Hutchins, Amie Fish, and Paul Aquilino, and filed on Aug. 10, 2010, the entire contents of which being incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to medical devices and, in particular, to delivery systems adapted for visualization of the deployment of a medical device. 
     BACKGROUND 
     Stents and stent delivery assemblies are utilized in a number of medical procedures and situations, and as such their structure and function are well known. A stent is a generally cylindrical prosthesis that is introduced via a catheter into a lumen of a body cavity or vessel. The stent is introduced into the cavity or vessel with a generally reduced diameter and then is expanded to the diameter of the cavity or vessel. In its expanded configuration, the stent supports and reinforces the cavity/vessel walls while maintaining the cavity/vessel in an open, unobstructed condition. 
     A stent delivery catheter may be delivered over a guidewire. A guidewire is flexible and has a smaller diameter than a stent delivery catheter, and therefore can be inserted into the body cavity or vessel of interest first, over and along which a stent delivery catheter can follow. Typically, when deploying an endoscopically delivered stent in a body cavity of interest, a guidewire is introduced into the body cavity through a working lumen defined in an endoscope to ensure proper placement of the prosthesis. The guidewire is used to ensure that the device is properly positioned and the deployment device is maintained in the proper position during deployment of the prosthesis. A physician advances an endoscope and the guidewire removably received therethrough into the body cavity of interest while observing an image received from the distal end of the endoscope. Once the distal end of the guidewire reaches the position of interest, as observed by the endoscope, the endoscope can be withdrawn, leaving the guidewire in place. Thereafter, a stent delivery catheter is passed over the guidewire and the stent is deployed. To observe and ensure proper deployment of the stent, the endoscope can be passed along the side of the stent during deployment. In addition, for example, when applying a stent in a blood vessel, fluoroscopy (x-ray imaging of a moving object) is often used to ensure proper placement and deployment of the stent, as well known in the art. 
     SUMMARY 
     In one example, the disclosure is directed to a prosthesis delivery device comprising at least one sheath, a prosthesis, an inner tubular member and at least two cameras. The at least one sheath removably covers the prosthesis therein. The at least one sheath comprises a distal end, a proximal end, an outer surface and a channel extending between the distal end and the proximal end. The channel defines an inner wall. The prosthesis extends in a compressed state within the channel. The inner tubular member slidably extends through the prosthesis, the inner tubular member comprising an elongated inner shaft with a distal tip at one end. The at least two cameras are engaged to the delivery device. 
     In another example, the disclosure is directed to a stent delivery device including at least one sheath, a stent and an inner tubular member. The at least one sheath removably covers the stent therein. The at least one sheath comprises a distal end, a proximal end, an outer surface and a channel extending between said distal end and said proximal end. The channel defines an inner wall. The stent extends in a compressed state within said channel. The inner tubular member slidably extends through the stent, and the inner tubular member comprises an elongated inner shaft with a distal tip at one end. The at least two cameras are engaged to the delivery device. 
     In another example, the disclosure is directed to a method for intraluminally positioning a prosthesis comprising providing a delivery device comprising at least one sheath removably covering a prosthesis therein, said at least one sheath includes a distal end, a proximal end, an outer surface and a longitudinal channel extending between said distal end and said proximal end, said channel defining an inner wall, said prosthesis extending in a compressed state within said longitudinal channel, an inner tubular member slidably extending through said prosthesis, said inner tubular member comprises an elongated inner shaft with a distal tip at one end, and at least two cameras engaged to said delivery device. The method further comprises activating said at least two cameras to provide images during positioning of said prosthesis, positioning said delivery device within a body lumen, and slidably retracting said at least one sheath relative to the inner tubular member to uncover said prosthesis and allow said prosthesis to radially expand against a wall of body lumen. 
     These and other features of the invention will be more fully understood from the following description of specific embodiments of the invention taken together with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view of one example delivery system in accordance with various techniques of this disclosure. 
         FIG. 2  is a schematic view of another example delivery system in accordance with various techniques of this disclosure. 
         FIG. 3  is a schematic view of another example delivery system in accordance with various techniques of this disclosure. 
         FIG. 4  is a schematic view of another example delivery system in accordance with various techniques of this disclosure. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Endoscopes are commonly used to deliver stents into a body cavity. When delivering a stent in a body cavity of interest, a guidewire is introduced into the body cavity through a working lumen defined in an endoscope. An endoscope, however, has a diameter that is relatively large with respect to the body cavity or body lumen of interest. Thus, the use of an endoscope to deliver a guidewire (and hence a stent delivery catheter) becomes difficult in some applications. For example, esophageal stents, gastrointestinal (GI) stents, and pulmonary stents are fairly large thereby requiring a larger delivery system. Therefore, positioning an endoscope along the side of a stent to observe its proper deployment requires an even larger space, which is not always available. As mentioned above, a physician is generally required to use an endoscope to place a guidewire, remove the endoscope leaving the guidewire in place, reinsert the endoscope along the guide wire, and insert the stent over the guidewire. 
     Still further, use of fluoroscopy to confirm proper positioning of a guidewire and/or a stent is a relatively cumbersome procedure that requires additional safety mechanisms for the patients as well as the doctors and their assistants. As such, a need exists for a vision system that is integral with the stent delivery system to provide a device that deploys and provides imaging in a single device. Additionally, a need exists for a stent delivery system having imagining capabilities to allow visualization of stent prior, during and after deployment without the use of an endoscope. A need exists for a single device that provides visualization and deployment of a prosthesis without the required use of fluoroscopy and/or a separate endoscope. In general, this disclosure describes delivery devices and methods used to deploy various implants or prostheses, e.g., stents, where the delivery device includes a vision system that is integral to the delivery system, thereby reducing or eliminating the need for the physician to reintroduce an endoscope when delivering a stent. 
       FIG. 1  is a schematic view of one example delivery system in accordance with various techniques of this disclosure. The delivery device  10  shown has two cameras, namely cameras  12 ,  16 , that are engaged to the delivery device. The delivery device  10  may include a first or outer sheath  22 , a second or middle sheath  24  and an inner member  25 . In one example configuration, the cameras are engaged to the delivery device by being integrally formed and embedded into the delivery device, e.g., in one of the sheaths  22 ,  24  and/or inner member  25 , by molding the cameras into the material of the delivery device during the manufacturing of the device. In another example configuration, the cameras are engaged to the delivery device by being fixedly attached, e.g., to one of the sheaths  22 ,  24  and/or inner member  25 , by way of adhesives, screws, or other fasteners. The first camera  12  located close to the distal tip  14  of the delivery device  10  is integrally formed from and embedded into the middle sheath  24  of the delivery device  10 . The first camera  12  allows for evaluation of the anatomy prior to stent release. 
     The second camera  16  located near the proximal end  18  of the stent  20  is integrally formed from and embedded into the outer sheath  22  of the delivery device  10 . The second camera  16  allows for observation of the proximal end  18  of the stent  20  during stent deployment. After the stent  20  has been deployed, the first camera  12  can be used to confirm stent placement and re-inspect the anatomy, as shown in  FIG. 3 . 
     In the example configuration depicted in  FIG. 1 , inner member  25  does not include a camera. In addition, cameras  12 ,  16  include illumination devices  26 ,  28 , respectively, to provide illumination within the lumen for enhanced visualization. 
     The cameras described in this disclosure may include an imaging chip, e.g., charge-coupled device (CCD) sensor or a complementary metal oxide semiconductor (CMOS) in nature, and a lens constructed with single or multiple optical elements. Additionally, the cameras may acquire an image through an imaging fiber bundles rather than directly. The images from the cameras are sent as imaging signals through hardwires or other signal transmitting members or wirelessly transmitted for reception and processing for display on an external device. The cameras of the present invention are of a size and shape driven by the mechanical attributes of the stent delivery system described. It is suggested that, in some examples, the cameras are miniature in nature (e.g., less than  4  millimeters in diameter or diagonal) with resolutions limited only by the state of the art of imaging arrays and lens construction, and lenses such as, but not limited to, micro-lenses and wafer-scale lenses are used. The cameras are positioned on the stent delivery device in such a way as to image specific areas of interest during navigation or stent deployment and therefore may have a primary direction of view at any angle. Camera lens parameters are likewise tuned at design to fulfill specific requirements of the application, e.g., field of view, depth of view, magnification, and the like. 
     The illumination device or system of the present invention provides light for the operation within a body lumen. The illumination device may include, but is not limited to, one or more light emitting diodes (LEDs), a fiber optic illumination guide for providing light from a light source, such as a laser or a white light source, and the like. Further, a lens may also be provided at the distal end of the illumination device to focus the illumination on the body lumen or tissue. 
     The light can be provided as a separate light source from the camera/camera processor or combined into a single piece of equipment. This equipment is located remotely from the stent delivery device and positioned as a matter of convenience to the practitioner. In the example configuration shown in  FIG. 3 , one or several additional connectors may be needed to provide the light from the separate light source. The light can also be produced by one or more LEDs located close to each camera. In this configuration, power is supplied to the LEDs via suitable electrical wires to provide simultaneous or independent control of LED light output. 
     One or more LEDs may also be located in the handle. In one example, the light may be transmitted to a location close to the camera via optical fibers. The optical fibers can form a single bundle, multiple bundles, or be incorporated evenly in the circumference of the middle sheath and/or outer sheath. The illumination device and/or camera may include, but is not limited to, an objective lens and fiber optic imaging light guide communicating with a practitioner, a camera, a video display, a sensor, such as a charge-coupled device (CCD) sensor or a complementary metal oxide semiconductor (CMOS) sensor, and the like. In any of the illumination configurations described, control of the light source or sources may be controlled manually or automatically through a camera processor driven by feedback control. Manual control of the illumination maybe coupled with automatic control of the camera pixel gains or automatic control of the illumination may be coupled with automatic camera pixel gain control. 
       FIGS. 2-4  are schematic views of three example delivery systems in accordance with various techniques of this disclosure. The devices of  FIGS. 2-4  may include a camera or camera and an illumination system integrally formed and within the inner member and embedded therein.  FIG. 2  shows delivery device  30  including an inner member  32 , a middle sheath  34  and an outer sheath  36 . The inner member  32  may include a first camera  38  located in the tip  42  which is directed towards the proximal end or a backwards viewing camera. It is contemplated that the camera can be located in a variety of positions such as shown in  FIGS. 3-4 . Additionally, this disclosure contemplates that the cameras described can be rotation cameras such that the cameras move/rotate to different positions/angles within its socket. 
     Referring now to  FIG. 2 , the first camera  38  allows for observation of the proximal end  18  of the stent  20  during stent deployment. After the stent  20  has been deployed, the first camera  38  can be used to confirm stent placement and re-inspect the anatomy. The inner member  32  may also include an illumination system (not shown). 
     In some example configurations, the middle sheath  34  may include an illumination system  44  and a second camera  40 , as depicted in  FIG. 2 . The illumination system  44  is integrally formed and embedded into the outer surface of the middle sheath  34 . The illumination system  44  may include a plurality of illumination devices  48  such as optical fibers that terminate at different locations on the external surface  46  of the middle sheath  34  to provide continuous illumination along the length of the delivery device. Illumination can be provided anywhere in the system, including inside the body of the catheter (catheter may be clear or opaque). 
     The second camera  40  allows for evaluation of the anatomy prior to stent release. As seen in  FIG. 2 , the second camera  40  may include an illumination system  41 . 
       FIG. 3  is a schematic view of another example delivery system in accordance with various techniques of this disclosure. Generally speaking,  FIG. 3  depicts a delivery device  50  that combines feature shown and described with respect to  FIGS. 1 and 2 , including cameras located in the middle sheath and outer sheath ( FIG. 1 ) and a camera on the inner member ( FIG. 2 ). More specifically,  FIG. 3  depicts a delivery device having cameras  60 ,  58 , and  70  integrally formed from and embedded into an outer sheath  52 , middle sheath  54  and an inner member  56 , respectively. 
       FIG. 3  depicts one example of the positioning and functioning of the cameras. In  FIG. 3 , the stent  20  is being deployed as the middle sheath  54  is retracted. The first camera  58  located close to the distal tip  62  of the delivery device  50  is integrally formed from and embedded into the middle sheath  54  of the delivery device  50 . The first camera  58  allows for evaluation of the anatomy prior to stent release. The second camera  60  located near the proximal extremity  64  of the stent  20  is integrally formed from and embedded into the outer sheath  52  of the delivery device  50 . The second camera  60  allows for observation of the proximal extremity  64  of the stent  20  during stent release. The inner member  56  may include third camera  70  on the distal tip  62 . The third camera  70  is a forward-facing camera. The third camera  70  allows for evaluation of the anatomy prior to stent deployment and also upon removal of the delivery device from the body lumen. Each of the cameras  58 ,  60 ,  70  are integrally formed from and embedded into a respective sheath, e.g., sheaths  54 ,  52 ,  56 , to provide a smooth exterior surface on the sheaths and minimize the overall diameter and size of each sheath and the delivery device as a whole. After the stent  20  has been deployed (not depicted), the first camera  58  and the second camera  60  can be used to confirm stent placement and re-inspect the anatomy. 
     Further, in some examples, cameras  58 ,  60  include illumination devices  66 ,  68 , respectively, to provide illumination within the lumen. The distal tip  62  may also include an illumination device (not shown). 
     In the example configuration shown in  FIG. 3 , the distal handle  72  is connected to the outer sheath  52 , the middle handle  78  is connected to the middle sheath  54  and allows for stent deployment when the middle sheath is retracted, and the proximal handle  88  is connected to the inner member  56 . A pin  74 , which can be removable, connects the outer sheath  52  to the inner member  56  to maintain the position of the camera  60  when the outer sheath  52  is pulled back. In the example shown in  FIG. 3 , a gap  76  in the middle sheath  54  allows motion of middle sheath  54  when the pin  74  is in place. In other examples, instead of the pin  74 , the proximal handle  88  and the distal handle  72  may be linked by an external connector. The pin ensures that the relative position of the proximal handle and distal handle is fixed when the middle handle is moved. This can also be achieved by connecting the proximal handle  88  and the distal handle  72 . 
     As seen in  FIG. 3 , the middle handle  78  may include a circuit board  80  to drive the cameras, a battery  82  to provide power to the cameras and illumination systems, an optional switch  84  to switch between cameras  60 ,  58  and  70 , and a video connector  86 . There is an electrical connector (not shown) between the middle handle  78  and distal handle  72  for the camera and illumination system. If the delivery device is disposable, the battery  82  can be removed from the handle to dispose of the device. In some examples, the battery  82 , circuit board  80 , switch  84 , and video connector  86  may be located in several different handles. Power is supplied from a power source to each of the cameras and illumination systems by various means, including wires or conductive material embedded into the particular sheath into which a respective camera and illumination system is embedded. 
       FIG. 4  is a schematic view of another example delivery system in accordance with various techniques of this disclosure. In particular,  FIG. 4  shows a two camera system including first camera  96  located at the proximal end  100  of the stent and second camera  98  located closer to the distal tip  102 , and a stent  20  is held in place on the delivery device  90  with a crochet suture  94 . Although two cameras are depicted, in some example configurations, a single camera may be installed. 
     The cameras  96 ,  98  in  FIG. 4  are mounted on a delivery device  90  that may include a single inner member  92 , such as Boston Scientific Corp&#39;s Ultraflex™ Stent Delivery System. In the example shown in  FIG. 4 , the cameras  96 ,  98  are integrally formed from the inner member  92  and embedded therein. The inner member  92  may be a solid rod or a hollow tube that allows for the passage of a guidewire to maintain a position of delivery device during deployment of a prosthesis, e.g., stent  20 , and/or to facilitate the accurate placement of the prosthesis, the passage of other material such as injecting contrast medium, or the passage of wires to supply power and video signals to/from the cameras. Further, the inner member  92  may include various markings along the length to provide a ruler or means of measuring the distance the device has travelled within the lumen. The delivery device may also include a means to steer the distal tip  102  to allow several degrees of liberty, e.g., two degrees, similar to a SpyScope® Access and Delivery Catheter, available from Boston Scientific, to facilitate device insertion. Further, the distal tip  102  may include a camera in various positions and integrated at various positions along the inner member  92 , such as a forward-facing camera as shown in  FIG. 3 . 
     Additionally, it is contemplated that the distal tip of the present invention may be transparent and may include multiple cameras therein. Further, the camera and illumination devices may be located side-by-side, or at different locations along the circumference of the inner member, middle sheath and/or outer sheath. It is further contemplated that the inner member, middle sheath and/or outer sheath can rotate independently of each other to allow for better visualization. 
     In another aspect, this disclosure is directed to a method for delivering a stent  20  into a body lumen or a method of use is provided. The device  10 ,  30 ,  50 ,  90  may be used for various applications such as esophageal stenting, colonic stenting, pulmonary stenting, urinary stenting, for various applications for orifice transluminal endoscopic surgery (NOTES), biopsy procedures and the like. The method of use includes providing a delivery device  10 ,  30 ,  50 ,  90 , the device  10 ,  30 ,  50 ,  90  includes at least one sheath or stent retaining member to retain the prosthesis, such as a stent, in a compressed state until delivery, and an inner member  25  and at least one camera and/or illumination system located on at least one sheath, or located on the sheath and inner member; and a prosthesis or stent  20 . The at least one sheath has a proximal end, a distal end, an outer wall and a longitudinal channel through the sheath defining an inner wall of the sheath and the stent  20  is juxtaposingly disposed to a distal portion of the inner wall and an inner member slidably disposed within the channel. The camera is activated to provide imaging during the delivery of the stent and the illumination system is activated to provide illumination within the lumen during the deployment process. The sheath is advanced through the lumen until properly positioned. Once the delivery device  10 ,  30 ,  50 ,  90  is positioned for deployment, the stent  20  may be released from the endoscopic stent delivery device  10 ,  30 ,  50 ,  90  by retracting the elongate sheath to release the stent  20  from the delivery device  10 ,  30 ,  50 ,  90  and/or by advancing the inner member to push the stent  20  out of the delivery device  10 ,  30 ,  50 ,  90 . The cameras provide imaging throughout the deployment of the stent  20  to verify accuracy and placement of the stent. The step of providing the endoscopic stent delivery device  10 ,  30 ,  50 ,  90  may further include a step of loading the stent  20  within the distal portion of the inner wall of the endoscope  10 ,  30 ,  50 ,  90 . The method may further include radially compressing the stent  20  prior to loading the stent  20  within the distal portion of the inner wall of the endoscope  10 ,  30 ,  50 ,  90 . 
     Additionally, the method of use may include selecting the proper prosthesis, e.g., esophageal stents, gastrointestinal (GI) stents, and pulmonary stents, according to the patient anatomy and disease progression; loading the desired prosthesis into the delivery device  10 ,  30 ,  50 ,  90  or selecting a pre-loaded delivery device  10 ,  30 ,  50 ,  90  including the proper prosthesis; connecting the delivery device to external capital equipment to supply power and necessary external elements to the device; introducing the device through the desired orifice and extending the device through a lumen to the location for deployment; confirming proper positioning by direct visual confirmation and exploring the lumen and/or stricture to ensure proper placement of prosthesis, e.g., the esophago-gastroenoscopy (EGO) is performed by the device; measuring the stricture and recording the measurements; advancing a guidewire into the invention through the stricture; deploying the prosthesis by pulling back on the sheath while the physician watched the deployment under direct visualization by the cameras; ensuring proper placement of the prosthesis by direct visualization once the prosthesis has been deployed; removing the device from the lumen. Additionally, the camera and/or illumination system may be attached to the device prior to introducing the device with the lumen. 
     Furthermore, any of the above-described viewing devices and/or illuminating devices may be disposed on or within or in conjunction with any of the above-described any of the above-described components. Further, the viewing device and the illuminating device may be disposed on different components of the present invention. 
     While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concept described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims. 
     Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.