System and method for introducing a prosthesis

Abstract

A method and apparatus for introducing a first elongate medical device and short wire guide that are coupled together into a work site and remotely disconnecting them within the work site such that a secondary device comprising a catheter member can be introduced over the wire guide to the work site, and / or a second wire guide can be introduced to the work site via a passageway of the primary access device. A system of indicia, such as radiopaque or viewable markers, permits the operator to monitor the relative alignment of the devices within the work site to determine when uncoupling has occurred. In one example of the method, a wire guide and primary access device (e.g., a sphincterotome) is coupled to the wire guide and introduced via a duodenoscope into the biliary system. After performing a first medical operation, the devices are uncoupled with the wire guide being left within the biliary system such that a secondary access device, such as a balloon, biopsy device, stent delivery catheter, dilator, etc., can be introduced to perform a second medical operation without a traditional over-the-wire exchange being required. In another example of the method, a prosthesis, such as a valve or stent, is placed within the work site coupled to a wire guide which is remotely disconnected within the work site and a secondary device, such as a dilation balloon or second prosthesis, is introduced into the work site after the first delivery system is removed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a non-provisional application which claims priority of provisional applications Ser. No. 60 / 491,408, filed Jul. 31, 2003, Ser. No. 60 / 563,968, filed Apr. 21, 2004, and Ser. No. 60 / 570,656, filed May 13, 2004.TECHNICAL FIELD [0002] This invention relates to medical devices, more particularly catheters and the like that are introduced into the patient over a wire guide. BACKGROUND OF THE INVENTION [0003] Minimally invasive medicine, the practice of gaining access into a blood vessel, duct, or organ using a wire guide to facilitate the subsequent introduction or placement of catheters and other medical devices, has been evolving since the Seldinger technique was first popularized during the late 1950s and 1960s. A significant advance was gaining the ability to exchange medical devices over a single indwelling wire guide without requiring displacement of the wire in the process and loss of access to the site. This ‘over ...

AI Technical Summary

Benefits of technology

[0014] In a first aspect of the invention, the system further includes an alignment indicator system, such as a system of indicia (e.g., radiopaque markers, external markings, endoscopic markings, etc.) located about the wire guide and / or first elongate medical device that can be utilized by the operator in locating the position of the distal end or distal portion of the wire guide relative to the proximal end of the coupling region, such as at a side access port or aperture (e.g., scive) through which the wire exits. The alignment indication system advantageously allows the physician to control when the two devices are coupled or uncoupled within the work site and helps provide confirmation that uncoupling has occurred. Without the ability to receive such confirmation, it would be extremely difficult for the physician to attempt, with any confidence, the uncoupling of the catheter from the wire guide (e.g., under fluoroscopic guidance) without knowing when uncoupling has occurred or is about to occur. Depending on the location or work site within the body and the device being delivered, an attempt to ‘blindly’ uncouple devices can lead to loss of wire guide access, especially if the device is prematurely withdrawn with the wire guide still engaged. Furthermore, the amount of relative movement between the device and the wire guide required to ensure that uncoupling had occurred would generally be much greater than if indicia were utilized, thus increasing risks such as the wire guide being withdrawn too far and access lost or encountering situations where there is insufficient space within the work site left for uncoupling to take place. Typical rapid exchange devices are not configured with the necessary radiographic or other appropriate indicia since the exchange procedure is intended to take place outside of the patient. The external exchange is a slower process and dictates removal of the first catheter before another catheter or wire guide can be advanced to the work site over an existing device (which always must be a wire guide or guiding device in traditional rapid exchange).

[0017] A third series of embodiments of the system of indicia include markings that are configured to be viewable by a fiberoptic endoscope or videoendoscope (e.g., duodenoscope, gastroscope, bronchoscope, ureteroscope, etc.). In devices configured for accessing the pancreatobiliary system, the indicia comprise a marking located on both the wire guide and elongate medical device disposed within an intermediate portion of each, which is typically located distal to the viewing lens or video chip of the scope, but proximal to the ampullary orifice during a typical procedure, such that they can be aligned by using the video monitor (or viewing port) to ascertain that uncoupling within the duct has occurred. The device may include other endoscopic indicia useful during the remote uncoupling procedure. For example, a biliary catheter may include a depth marking at a designated distance from the catheter tip (e.g., 10 cm) which when buried within the papilla, indicates that IDE can be performed safely within the duct without risking loss of wire guide access. Furthermore, the distal portion of the wire guide can be distinctive in appearance (e.g., black) as a visual cue to warn the physician if the tip is in danger of pulling completely out of the duct, which would require recannulation of the papilla. The second and third system of indicia do not require external imaging, thus the physician can advantageously limit the time that the patient is exposed to fluoroscopy. For example, fluoroscopy can be used only at selected, critical times during the procedure with at least one of the other types or indicia being used elsewhere for alignment guidance.

[0020] When the physician, using at least one component of the alignment indicator system, has determined that the tip of the wire guide has disengaged from the coupling region of the primary access device, the first device can be easily removed by merely pulling it back out of the endoscope accessory channel (or introducer sheath in the case of vascular or certain other non-endoscopic applications). Removal is greatly facilitated by the elimination of friction which would have otherwise existed between the wire guide and catheter if the wire resided within the channel or lumen. Although some of the aforementioned MICROVASIVE RX™ biliary devices (e.g., the AUTOTOME™ sphincterotome) include a side port within the distal portion, all of the devices lack the combination of indicia that make a remote or intraductal exchange clinically practical or even possible. Furthermore, those devices that include an open channel extending proximally of the side access port cannot be uncoupled within the duct or work site regardless of the lack of indicia since the proximal portion of the wire guide tends to ‘seek’ and reenter the channel when both devices are residing within the accessory channel of the scope. Thus, remote disconnection is rendered impossible without some means to releasably disengage the wire from the channel.

[0023] After gaining access to the passageway by one of the aforementioned routes, the wire guide is guided under external imaging, such as fluoroscopy, into the desired location. Optionally, if the first device is a sphincterotome or other type of deflectable catheter, the operator can manipulate the shape and orientation of the catheter tip portion to help guide the tip of the second wire guide into the opposite (or side) branch of the duct or vessel. Orientation within the work site can be facilitated with a rotatable handle to direct the tip. Furthermore, it has been demonstrated that certain shorter wire guides, such as the illustrative 185 cm biliary wire guide of the present invention, are sufficiently torqueable such that an operator can simply rotate the wire with his or her fingers to achieve similar results in most instances.

[0024] In another aspect of the invention, primary access devices further include an elongate engagement member configured to releasably engage with the wire guide within or about the coupling region (e.g., the distal passageway of the tubular member). Embodiments include using a flexible wire stop (e.g., a nylon stylet) configured to wedge the wire guide within the passageway when in the fully advanced position, and a thread-like member (e.g., suture) that ensnares the wire guide and provides tension to maintain it in a longitudinally secure position relative to the tubular member. When an elongate engagement member is not used during introduction, such as when secondary access devices are being introduced over the already indwelling wire guide, a stiffening stylet may be optionally maintained in the passageway of the tubular member to add rigidity to the device during introduction and / or for advantageously traversing scives in the tubular member, such as the side access port, to prevent kinking thereabout.

[0025] In still another aspect of the invention, the system of devices adapted for remote uncoupling or ultra-short wire techniques includes a delivery catheter for plastic tubular drainage stents and a technique for deployment that allows for placing multiple stents side by side within the bile duct using a single cannulation procedure. By placing the side access port on the inner carrying member (over which the stent is mounted) at a point distal to the stent, the wire guide can be uncoupled within the duct and the stent deployed without having to withdraw the entire system, including the wire, in the process. The junction between the inner carrying member and wire guide can be advantageously used to ‘catch’ the stent when the inner member is pulled back, thus allowing the entire delivery system, including the stent, to be pulled back within the duct. This feature, which is not present in other stent delivery systems, is especially important to address situations when the stent is advanced too far into the duct and needs to be repositioned. After the stent is in the correct position for deployment, the inner carrying member is advanced and / or the wire guide withdrawn to uncouple the two, allowing the inner carrying member to be withdrawn through the stent and from the duct while the wire guide remains behind for a second stent delivery catheter (and additional stents) to be advanced into the duct and placed along side the first stent. Pigtail stents and others that include shaped distal portions for anchoring can be temporarily straightened during delivery by the wire guide which traverses the coupling region.

Problems solved by technology

Without the ability to receive such confirmation, it would be extremely difficult for the physician to attempt, with any confidence, the uncoupling of the catheter from the wire guide (e.g., under fluoroscopic guidance) without knowing when uncoupling has occurred or is about to occur.

Depending on the location or work site within the body and the device being delivered, an attempt to ‘blindly’ uncouple devices can lead to loss of wire guide access, especially if the device is prematurely withdrawn with the wire guide still engaged.

Furthermore, the amount of relative movement between the device and the wire guide required to ensure that uncoupling had occurred would generally be much greater than if indicia were utilized, thus increasing risks such as the wire guide being withdrawn too far and access lost or encountering situations where there is insufficient space within the work site left for uncoupling to take place.

Typical rapid exchange devices are not configured with the necessary radiographic or other appropriate indicia since the exchange procedure is intended to take place outside of the patient.

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