Surgery – Means for introducing or removing material from body for... – Treating material introduced into or removed from body...
Reexamination Certificate
1996-02-29
2001-05-08
Nguyen, Anhtuan T. (Department: 3763)
Surgery
Means for introducing or removing material from body for...
Treating material introduced into or removed from body...
C604S093010, C604S514000, C604S104000, C604S164100
Reexamination Certificate
active
06228052
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to an introducer system for a lead or catheter employing a dilator and introducer sheath assembly for dilating a body vessel in preparation for introducing the lead or catheter through the lumen of the introducer sheath that provides for the injection of radiopaque contrast media to observe the cause of an impediment to advancement of the assembly into the vessel lumen.
BACKGROUND OF THE INVENTION
A multi-step procedure is often used to introduce electrical stimulation leads, catheters, probes or the like into a body vessel, most notably into the vascular system, typically the venous system. Generally this procedure consists of inserting a hollow needle into a blood vessel, such as the subclavian vein. A wire guide is then passed through the needle into the interior portion of the vessel. The needle is then withdrawn and an introducer sheath and dilator assembly is then inserted over the wire guide into the vessel. The assembly is advanced into a suitable position within the vessel, i.e. so that the distal end is well within the vessel but the proximal end is outside the patient. Next, the dilator and wire guide are removed from the introducer sheath lumen. The introducer sheath is left in position and therefore offers direct access from outside the patient into the blood vessel lumen. Then, a lead, catheter or the like can be passed through the introducer sheath lumen into the blood vessel lumen and ultimately be positioned in a desired site, e.g., within the patient's selected heart chamber or an associated blood vessel.
Such a system and method is commonly employed for percutaneously introducing pacing leads for permanent or temporary pacemakers or arrhythmia control devices. In the implantable pacemaker context, an implantable pulse generator is electrically connected to the heart by at least one pacing lead, e.g. an endocardial lead introduced transvenously. More specifically, an endocardial lead provides an electrical pathway between the pacemaker pulse generator, connected to the proximal end of the lead, and endocardial tissue, in contact with one or more electrode at the distal end of the lead. Endocardial tissue refers to a specific layer of tissue in the interior of the heart's chambers. In such a manner, electrical pacing pulses emitted by the pacemaker travel through the endocardial lead conductor and depolarize the endocardial tissue of the heart in contact with the electrode(s). The contraction of the heart is effected by the propagation of the evoked depolarization.
Endocardial pacing leads are often placed in contact with the endocardial tissue by passage through a venous access, such as the subclavian vein or one of its tributaries. In such a manner, transvenous endocardial leads offer as an advantage that they may be placed into contact with the heart without requiring major thoracic surgery. Rather, once the transvenous endocardial leads are introduced into a vein and maneuvered therefrom into contact with the heart, the vein access may be closed and the lead connector end may be tunnelled under the skin to the implant site of the pulse generator and attached thereto.
Such pacemaker leads typically have a relatively bulky connector pin assembly at the proximal end, and the introducer sheath is removed from the lead body at the end of the procedure by being split apart. In such a manner, the introducer sheath does not have to be removed over the relatively bulky connector pin assembly at the proximal end of the lead body.
One purpose of this well known procedure is to expand the lumen of the blood vessel accessed at the puncture site so that it can receive the distal end of the lead. The distal tip of the dilator is tapered to expand the blood vessel lumen as it is advanced through it. After the dilator is withdrawn, the sheath maintains the expansion of the blood vessel lumen and provides an introducer lumen for the distal end and body of the lead.
A problem exists in pacemaker patients who have had multiple leads implanted over time. Scar tissue at the site of lead introduction into a blood vessel during implantation has been found to create difficulties with past lead introduction systems. Specifically the relatively tough scar tissue hinders the introduction of a dilator and introducer sheath assembly. Many times, only through use of larger incisions than are otherwise desirable is such an assembly able to be inserted and advanced.
To provide such access under the best of circumstances, the introducer sheath must be flexible in order to permit the introducer sheath to bend and conform with blood vessel curves and bends. After placement in the vessel lumen, the introducer sheath end is substantially parallel to the blood vessel lumen, and a lead which is introduced therethrough is properly aligned with the vessel lumen. If the sheath did not conform to the vessel shape, a lead introduced through its distal end opening would abut against the vessel wall, possibly injuring the vessel wall and damaging the lead.
When an irregularity or scar tissue impediment to advancement of the assembly is encountered, it is necessary to remove the assembly from the incision into the blood vessel and to explore the reasons for it. One approach is to inject a radiopaque dye or contrast medium into the blood vessel lumen and observe it under fluoroscopy to identify any blockage sites, vessel wall perforations, scar tissue or other impediments to advancement. It may be that none are observable, and the procedure is repeated either with the same or with a different combination of dilator and introducer sheath. The same problem may be repeated. Even if blockage sites, perforations or other impediments are observed, the exact relation of the problem with the distal end portion of the assembly cannot be observed because it is no longer in place.
Since the guide wire lumen of the dilator is available, the physician may attempt to inject the dye or contrast media through it alongside the guide wire. It is difficult or not possible to pressurize the injection of the dye or contrast media and it also escapes back out the proximal end opening of the guide wire lumen of the dilator.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a method of visualizing an impediment to the advancement of an introducer sheath and dilator assembly over a guide wire in a blood vessel without removing the assembly or the guide wire.
It is a further object of the present invention to provide an introducer system having a sheath and dilator formed to allow the injection of pressurized radiopaque contrast media at the distal end portion of the assembly to visualize impediments to the advancement of the assembly into the blood vessel lumen.
These objects are met by the present invention which provides an introducer system for a lead, catheter, probe or the like, employing a dilator and introducer sheath assembly advanced over a guide wire for dilating a body vessel in preparation for introducing the lead, etc., through the lumen of the introducer sheath that incorporates the capability of visualizing an impediment in the blood vessel, to the advancement of an introducer sheath and dilator assembly over the guide wire without removing the assembly or the guide wire from the blood vessel.
In particular, means are provided for injecting a radiopaque contrast media into the blood vessel lumen through a further contrast media injection lumen while the dilator remains in position in the blood vessel. The means preferably comprises an injection lumen formed in the dilator body isolated from the guide wire lumen and in fluid communication with a side port formed in a hub assembly at the proximal end of the dilator body and an injection port formed in the distal end of the dilator body. Preferably, the injection port is formed in a tapered distal end portion of the dilator.
In use, the guide wire and dilator/introducer sheath assembly may be retained in situ in the event that the introduction of the assembly is impeded, a
Jaro Michael J.
Medtronic Inc.
Nguyen Anhtuan T.
Pattom Harold
Thompson Michael M.
LandOfFree
Dilator for introducer system having injection port does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dilator for introducer system having injection port, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dilator for introducer system having injection port will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2451377