Cardiac electrode attachment procedure
Surgical procedure and surgical instruments include an electrode structure for insertion through tissue superiorly of a subxiphoid incision to a position posterior of an aspect of the sternum and anterior of the pericardium. The electrode structure may be expanded, for example, including an inflatable member to position a number of electrodes of the electrode structure in contact with the pericardium. Alternatively, an electrode structure on an insertion cannula may be retained in contact with the pericardium by the cannula positioned within the dissected tissue. Electrical conductors from the contacting electrodes are routed through the tract of dissected tissue toward the subxiphoid incision for attachment to a generator that is implanted in a subcutaneous pocket near the subxiphoid incision.
This application claims benefit under 35 U.S.C. § 120 as a continuation of application Ser. No. 10/369,980 filed on Feb. 18, 2003 by Albert K. Chin, which is a continuation-in-part of application Ser. No. 10/346,663 entitled “Endoscopic Subxiphoid Surgical Procedures,” filed on Jan. 17, 2003 by Albert K. Chin, and is a continuation-in-part of application Ser. No. 10/347,212, entitled “Apparatus and Methods for Endoscopic Surgical Procedures,” filed on Jan. 17, 2003 by Albert K. Chin, which applications are incorporated in their entireties herein by this reference thereto.
FIELD OF THE INVENTIONThis invention relates to surgical instruments and procedures for placement of cardiac pacer or defibrillator electrodes, particularly via subxiphoid incision and insertion of an electrode structure in an extrapericardial position with a connected generator disposed in a subcutaneous pocket adjacent the subxiphoid incision.
BACKGROUND OF THE INVENTIONContemporary surgical techniques for installing electrodes on the heart of a patient that is at risk for ventricular fibrillation or bradycardia arrhythmias commonly involves insertion of a wire electrode through the patient's venous system into the heart, and connection of the electrode to an implanted defibrillator or pacemaker. These procedures are commonly performed in a cardiac catheterization lab, under fluoroscopic x-ray guidance. It is desirable to place defibrillator or pacing electrodes in contact with the pericardium of the heart with minimal trauma and simple surgical techniques that can be rapidly implemented, with or without the need for fluoroscopic guidance.
SUMMARY OF THE INVENTIONIn accordance with one embodiment of the present invention, an electrode structure includes an inflatable balloon having surface-oriented electrode patches for positioning extrapericardially at a posterior aspect of the sternum. The electrode structure is positioned via a subxiphoid incision and entry along a tract of dissected tissue to the posterior aspect of the sternum. Orientation of the electrode patches is gauged via radiological or mechanical techniques, and the balloon is inflated to engage the electrode patches on a surface thereof with selected regions of the pericardium. Surgical instruments for inserting and placing the electrode structure within the posterior aspect of the sternum are specifically configured to facilitate the placement via the subxiphoid entry. Associated electrical conductors are disposed substantially along the dissected tract to an implantable pacer or defibrillator that is inserted into a subcutaneous pocket formed adjacent the subxiphoid entry incision.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to
The proximal end of the support tube 19 may be internally threaded, and mating threads on the distal end of the central shaft 9 screw into the support tube to fix the balloon 23 onto the central shaft. The hub 15 attached to the proximal end of the support tube 19 includes a non-round cavity that mates with the corresponding connector 13 on the distal end of the central shaft. Thus, when the support shaft 19 and the central shaft 9 are screwed together, or are otherwise detachably connected, the assembly may be rotated, and torque may be transmitted to the tip 21 of the instrument for bluntly dissecting tissue. Keying of the connectors 13, 15 in this manner also preserves the orientation of the balloon 23 so that the patch electrodes 25, 27 can be properly oriented on the inferior surface of the balloon during placement thereof on the anterior pericardium. In one embodiment, the balloon 23 deflates upon detachment of the central shaft 9 from the support shaft 19. However, the balloon 23 stays in position on the anterior pericardium due to the conformance of the balloon 23 to the extra-pericardial cavity formed during balloon inflation. Similarly, frictional members or small protrusions can be disposed on the balloon 23 to maintain the position of the electrodes.
In another embodiment of the invention, a sealing valve may be added to the connector 15, such as a check-ball valve 35, to ensure that the balloon does not deflate upon detachment of the central shaft 9. The balloon retained in inflated configuration is less likely to migrate out of position after insertion. After several days to several weeks, the balloon may be deflated via percutaneous needle puncture in the intercostal space. Additionally, the balloon surface may be coated or covered with fabric or coarse-mesh material or other suitable material 50 that promotes fibrous adhesions to hold the balloon in place. Such coating or covering may be applied to the side opposite the patch electrodes 25, 27, or may be on both sides of the balloon except at the locations of the electrodes.
Referring now to
The inflatable member 23 includes two substantially circular membranes of flexible but substantially inelastic material such as mylar or polyurethane that are bonded together substantially only around the periphery thereof (and to the support shaft 19) to form a disk-like balloon having an interior between the membranes that is disposed in fluid communication with the hollow support shaft 19. One disk-like surface of the member 23 supports one or more electrode patches 25, 27 that are spaced apart to form pericardium-engaging contact electrodes. The patch electrodes 25, 27 may include surface pads of sputtered metal or organic conductive compounds or mesh or spiral grids that are affixed to the outer surface of the posterior membrane, as shown in the bottom view of
Referring now to
Another embodiment of the present invention, as illustrated in
Once the instrument is advanced to the desired position, the sheath 41 is retracted to expose the balloon 23. The balloon is inflated to create a cavity anterior to the anterior portion of the pericardium. The balloon 23 contains two or more patch electrodes 25, 27, as previously described herein, that are oriented on the inferior side of the balloon. The balloon is substantially flat with an outer diameter of approximately 7-8 cm. Balloon inflation creates a cavity in adjacent tissue that conforms to the dimensions of the balloon 23 to hold the balloon 23 in the correct position against the heart 100, as shown in
Referring now to
Referring now to the flow chart of
After the instrument in an embodiment of
After the instrument in an embodiment of
Therefore, the surgical instruments and surgical procedures for placing an electrode structure in contact with the heart advances an electrode structure through a subxiphoid access tract to a posterior aspect of the sternum and the anterior pericardium. The simplified surgical procedure using an embodiment of the present invention facilitates proper placement of the electrode structure with fluoroscopic visualization or x-ray positioning for minimal trauma to the patient. Conductive leads from contact electrodes of the electrode structure are routed along the access tract to the subxiphoid incision for connection to a pulse generator or defibrillator that is implanted within a subcutaneous pocket near the subxiphoid incision.
Claims
1. A surgical procedure for contacting electrodes supported on an electrode structure to the heart of a patient, the procedure comprising the steps for:
- forming a subxiphoid incision on the patient;
- dissecting tissue along a tract superiorly from the subxiphoid incision to a posterior aspect of the patient's sternum near the patient's heart for advancing the electrode structure through the subxiphoid incision and along the tract of dissected tissue to the posterior aspect of the patient's sternum; and
- positioning the electrode structure within the region posterior to the posterior aspect of the patient's sternum and anterior to the patient's heart to form contact therewith of a number of the electrodes of the electrode structure.
2. The surgical procedure according to claim 1 including:
- expanding the electrode structure within said region to form the contact with the pericardium outside the patient's heart by each of the number of electrodes.
3. The surgical procedure according to claim 1 in which the electrode structure includes an inflatable member and conductors extending from each of the number of electrodes, and further comprises the steps for:
- inflating the member to contact the number of electrodes with the patient's heart; and
- routing the conductors along the tract of dissected tissue toward the subxiphoid incision.
4. The surgical procedure according to claim 1 including a generator for supplying signals to the number of electrodes, and further comprising the steps for:
- connecting a conductor for each of the number of electrodes to receive signals from the generator; and
- implanting the generator subcutaneously in the patient near the subxiphoid incision.
5. The surgical procedure according to claim 3 performed using an insertion instrument and further comprising the steps for:
- confining the inflatable member within the insertion instrument in one configuration thereof;
- inserting the insertion instrument in the one configuration through the subxiphoid incision and along the tract of dissected tissue to the posterior aspect of the patient's sternum;
- re-configuring the insertion instrument in another configuration to expose the inflatable member; and
- disengaging the insertion instrument from the inflated member for removal of the insertion instrument through the subxiphoid incision.
6. The surgical procedure according to claim 1 including radiologically visualizing placement of the electrode structure advanced to the posterior aspect of the patient's sternum through the subxiphoid incision and along the tract of dissected tissue.
7. The surgical procedure according to claim 5 in which the insertion instrument is generally U-shaped with one portion for insertion through the subxiphoid incision, and with another portion in substantial alignment with the one portion and spaced therefrom, and further comprising the steps for:
- inserting the one portion through the subxiphoid incision to position the electrode structure at the posterior aspect of the patient's sternum with said another portion extending outside the patient's body superiorly from the subxiphoid incision substantially coextensively with the one portion inside the patient's body.
8. The surgical procedure according to claim 7 further comprising the step for:
- determining positioning indicia for said another portion of the insertion instrument on the outside of the patient's body superiorly of the subxiphoid incision for selectively positioning the one portion of the insertion instrument within the patient's body with reference to the positioning indicia.
9. The surgical procedure according to claim 1 performed with an electrode structure disposed near the distal end of an elongated flexible body, the procedure including the steps for:
- selectively stiffening the elongated body for positioning the electrode structure; and
- removing stiffening of the elongated body following positioning of the electrodes in contact with the patient's heart.
10. The surgical procedure according to claim 9 in which the elongated body slidably carries a substantially rigid obturator; and
- removing stiffening includes removing the obturator carried by the elongated body.
Type: Application
Filed: Jan 5, 2006
Publication Date: Jun 1, 2006
Inventor: Albert Chin
Application Number: 11/326,933
International Classification: A61N 1/05 (20060101);