Surgery – Instruments – Electrical application
Reexamination Certificate
2002-04-24
2004-05-11
Rollins, Rosiland K. (Department: 3739)
Surgery
Instruments
Electrical application
C607S115000, C607S119000, C604S164130
Reexamination Certificate
active
06733500
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to delivery of various devices or agents into a targeted area of the body, and in particular, the present invention relates to a method and apparatus for accurately delivering medical devices such as leads, electrophysiology catheters, and therapeutic agents into large-organ vessel systems such as the coronary vasculature.
In treating conditions such as arrhythmia, one technique is to destroy or damage heart tissue that causes or is involved with the arrhythmia by suitably heating the tissue, e.g., by applying a laser beam or high-frequency electrical energy such as radio-frequency (RF) or microwave energy.
For such treatment to be effective, the location of the tissue site causing or involved with the arrhythmia must be accurately determined in order to be able to contact heart tissue adjacent the desired location with a tissue-destroying device. A high degree of accuracy in determining this site is paramount so that an excessive amount of viable tissue is not destroyed adjacent the site. For example, the average arrhythmogenic site consists of about 1.4 cm
2
of endocardial tissue, whereas a re-entrant site might be much larger. RF ablation techniques produce lesions about 0.5 cm
2
of diameter, so a number of lesions are typically generated in order to ablate the area of interest. If the site is not accurately mapped, much of the viable tissue surrounding the site will be unnecessarily destroyed.
To determine the location of the tissue to be ablated, it is widely known to use elongated intravascular signal sensing devices that are advanced through the patient's vasculature until the distal portions of the device are disposed within one or more of the patient's heart chambers, with one or more electrodes on the distal portion of the device in contact with the endocardial lining. Such devices may also be advanced within a patient's coronary artery, coronary sinus, or cardiac vein. Sensing devices such as those disclosed in U.S. Pat. No. 5,967,978 to Littmann et al., and combination sensingablation devices such as those disclosed in U.S. Pat. No. 6,002,956 to Schaer are typical.
Guiding catheters such as those disclosed in U.S. Pat. Nos. 6,021,340 and 5,775,327 to Randolph et al. may be used to rapidly advance such devices into a patient's cardiac vein draining into the coronary sinus. A particular advantage of the catheters disclosed in these references is the presence of an inner lumen and distal port on the catheter shaft, which, in conjunction with a distal balloon, allows for the deployment of contrast fluid distal to the distal end of the catheter for visualizing the venous structure.
The following U.S. Patents discuss related devices and methods for their use: U.S. Pat. Nos. 5,509,411, 5,645,064, 5,682,885, 5,699,796, 5,706,809, and 5,701,298, each to Littmann et al; U.S. Pat. Nos. 5,881,732 and 5,645,082, each to Sung et al; U.S. Pat. No. 5,766,152 to Morely et al; U.S. Pat. Nos. 5,782,760 and 5,863,291, each to Schaer; U.S. Pat. No. 5,882,333 to Schaer et al., and U.S. Pat. No. 6,122,552 to Tockman et al.
However, despite the advantages of these sensing devices and guiding catheters, it remains quite difficult to accurately and reliably contact the various curved shapes one encounters in the endocardial lining. This is due to the frequent inability to customize the shape of their distal portion, or at least the inability to instantaneously and accurately adjust their shape upon demand during deployment to conform to the shape of the tissue of interest.
Concerns similar to those described above are associated with the placement of leads within the heart and other areas of the coronary vasculature. For example, pacemakers, defibrillator/cardioverters, and other implantable medical device (IMDs) may employ one or more electrodes that are maintained in contact with a patient's heart muscle and through which electrical stimulation of the heart muscle is achieved. Such devices typically employ a flexible conductive lead that connects a remotely positioned and implanted power source to the one or more electrodes. Secure placement of the electrodes in the selected heart chamber (typically the right atrium) or in a coronary vein or artery is required to assure appropriate and reliable depolarization or “capture” of cardiac tissue by electrical stimuli delivered by the IMD.
Many problems exist with reliably and accurately placing medical electrical leads and other similar devices such as catheters within the heart and associated vasculature. For instance, when placing transvenous leads or catheters, it is often difficult to engage the coronary sinus and sub-select the proper vessel into which the lead or catheter is to eventually be placed. Moreover, once placed, transvenous devices suffer from a relatively high rate of dislodgment from sites adjacent to, or on, the epicardium. Such dislodgement may result in a loss of capture or, at best, a reduction of the degree of electrical coupling between the electrode and the myocardium. More accurate and secure placement of the lead or catheter would not only reduce the difficulty and time associated with lead placement, but would reduce the risk of subsequent dislodgment as well.
There thus is a need for a method and system for placing intralumenally-deployed devices such as electrophysiology catheters and leads into selected areas of the coronary vasculature in a highly accurate and reliable fashion.
SUMMARY OF THE INVENTION
The present invention is directed to loading device for loading a guide wire within a medical electrical lead having a lead distal tip and a lumen for receiving the guide wire. The loading device includes a navigation portion, having an outer portion, and extending from a front end to a back end, and having an opening formed at the back end, and an engagement cavity that receives and properly orients the lead distal tip to align the lumen of the lead with the opening of the navigation portion during the loading of the guide wire within the lead. A first side wall is spaced from a second side wall to form a slot extending along the outer portion from the front end to the back end of the navigation portion, and the guide wire is advanced through the slot as the lead having the guide wire loaded therein is removed from the loading device.
In accordance with another aspect of the present invention, a system for delivering a medical electrical lead within a coronary venous system includes an introducer kit for establishing venous access to the coronary venous system, a plurality of delivery sheaths, each corresponding to a desired approach to a coronary sinus of the coronary venous system, for establishing a navigation pathway within the coronary venous system through the venous access, and a hemostasis valve coupled to a delivery sheath of the plurality of delivery sheaths. A loading device that is utilized to load a guide wire within a lead lumen of the lead includes a navigation portion, having an outer portion, and extending from a front end to a back end, and having an opening formed at the back end. An engagement cavity of the loading device receives and properly orientates a lead distal tip during the loading of the guide wire within the lead, and a first side wall is spaced from a second side wall to form a slot extending along the outer portion from the front end to the back end of the navigation portion, so that the guide wire is advanced through the slot as the lead having the guide wire loaded therein is removed from the loading device. The guide wire guides delivery of the distal tip of the medical electrical lead to a target site within the coronary venous system through the hemostasis valve and the delivery sheath, and, subsequent to the distal tip being delivered to the target sight, the hemostasis valve is advanced over the connector of the medical electrical lead to remove the hemostasis valve from the medical electrical lead.
In accordance with yet another aspect of the present invention, a method of delive
Bjorklund Vicki L.
Gardeski Kenneth C.
Hine Douglas S.
Kelley James F.
Maier John J.
Girma-Wolde-Michael
McDowall Paul H.
Medtronic Inc.
Rollins Rosiland K.
Soldner Michael C.
LandOfFree
Method and system for delivering a medical electrical lead... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for delivering a medical electrical lead..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for delivering a medical electrical lead... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3218522