US 20070010793 A1
A device and method for accessing a pericardial space of the heart includes a shaft having a cavity at a distal end, a suction lumen terminating in a distal port within the cavity and a hollow needle having a distal tip extending into the cavity. The cavity may be a recess in the shaft into which the distal tip of the needle fixedly protrudes. In other embodiments, the cavity is formed by an inflatable member positioned at the distal end of the shaft and the needle is slidable relative to the shaft. Suction is applied at the cavity to draw a pericardial bleb. The needle pierces the pericardial bleb for accessing the pericardial space and also facilitates delivery of payloads into the pericardial space.
1. A device for accessing a pericardial space of a heart, the device comprising:
a shaft extending from a proximal end to a distal end, the shaft defining a cavity disposed near the distal end, and a suction lumen terminating in at least one distal suction port located within the cavity; and
a hollow needle extending through the shaft and fixed in position relative to a longitudinal axis of the shaft, the needle having a sharp distal end protruding into the cavity downwardly toward a heart surface at an angle with respect to a longitudinal axis of the shaft.
2. The device of
3. The device of
4. The device of
5. The device of
6. The device of
7. The device of
8. The device of
9. A device for accessing a pericardial space of a heart, the device comprising:
a shaft extending from a proximal end to a distal end, the having a suction lumen terminating in at least one distal suction port near the distal end and an inflation lumen;
an inflatable member positioned near a distal end of the shaft, the inflatable member having a collapsed configuration and an inflated configuration defining a cavity, the inflatable member in communication with the inflation lumen; and
a hollow needle adapted for advancement through the shaft into the cavity.
10. The device of
11. The device of
12. The device of
13. The device of
14. The device of
15. The device of
16. A method of accessing the pericardial space, the method comprising:
maneuvering a distal end of a shaft to the pericardial surface;
inflating an inflatable member disposed at the distal end of the shaft to an inflated configuration defining a cavity adjacent the pericardial surface;
applying suction within the cavity to draw the pericardium into the cavity and create an enlarged region;
piercing the pericardium within the cavity to access the pericardial space; and
inserting a payload through the pierced pericardium and into the pericardial space.
17. The method of
18. The method of
19. The method of
20. The method of
The present invention relates to medical devices and methods for accessing an anatomical space of the body. More specifically, the invention relates to devices and methods for accessing the pericardial space of the heart in a minimally-invasive manner.
The human heart is enveloped within a tissue structure referred to as the pericardium, which comprises two major parts. The inner layer of the pericardium lies immediately over the myocardium (heart muscle) and is referred to as the visceral pericardium or epicardium. The outer layer, forming a sac around the visceral pericardium, is referred to as the parietal pericardium. Normally these two layers lie in close contact with each other and are separated only by a thin layer of pericardial fluid, which allows the heart to move within the parietal sac with minimal friction. The potential space between the visceral and parietal pericardia is referred to as the pericardial space. The visceral pericardium is commonly referred to as the epicardium and the parietal pericardium is commonly referred to as the pericardium. This naming convention will be used herein.
Access to the pericardial space is necessary for a variety of medical procedures, including treatment of infections, injuries, and heart defects. For example, cardiac rhythm management systems such as pacemakers, implantable pulse generators, and implantable cardioverter defibrillators include electrode bearing leads for sensing and stimulating the heart. These leads can be deployed from inside or outside the heart. In the latter case, the pericardial space is typically traversed to reach the epicardium for lead implantation and attachment.
Part of the challenge in accessing the pericardial space stems from its minimal thickness. When making an incision or perforation in the pericardium, it is preferable to avoid also puncturing the underlying epicardium and damaging the myocardium or a coronary vessel. The close proximity of the epicardium to the pericardium makes this difficult. Another important consideration is the trend toward minimally-invasive surgical techniques, which generally are associated with a host of advantages including lower costs and fewer complications.
There is a need in the art for improved, efficacious methods and devices for penetrating the pericardium and thereby accessing the pericardial space, which minimize the risk of damaging other heart tissues. There is a further need for such methods and devices that are compatible with minimally-invasive surgical techniques.
According to one embodiment, the present invention is a device for accessing a pericardial space of a heart. The device includes a shaft that extends from a proximal end to a distal end and defines a cavity disposed near the distal end. The shaft further includes a suction lumen terminating in at least one distal suction port located within the cavity. A hollow needle extends through the shaft and is fixed in position relative to a longitudinal axis of the shaft. The needle has a sharp distal end protruding into the cavity toward a heart surface at an angle with respect to a longitudinal axis of the shaft.
According to another embodiment, the present invention is a device for accessing a pericardial space of a heart and includes a shaft extending from a proximal end to a distal end, and having a suction lumen terminating in at least one distal suction port near the distal end and an inflation lumen. An inflatable member is positioned near a distal end of the shaft and has a collapsed configuration and an inflated configuration that defines a cavity. The inflatable member is in communication with the inflation lumen. Finally, the device includes a hollow needle adapted for advancement through the shaft into the cavity.
According to still another embodiment, the present invention is a method of accessing the pericardial space in which a distal end of a shaft is maneuvered to the pericardial surface. An inflatable member disposed at the distal end of the shaft is inflated to an inflated configuration defining a cavity adjacent the pericardial surface. Suction is applied within the cavity to draw the pericardium into the cavity and create an enlarged region. The pericardium within the cavity is pierced to access the pericardial space and a payload is inserted through the pierced pericardium and into the pericardial space.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
As shown in
The needle 14 is a hollow tubular structure defining an inner bore 33 and having a sharp distal tip 36. The needle tip 36 protrudes into the recessed region 18 of the shaft 12 a fixed distance and, in one embodiment, is angled downwardly, or towards the pericardium 22. However, the needle 14 extends downwardly no further than the depth, d, of the cavity 18, such that the needle tip 36 is wholly located within the cavity 18. This prevents the needle tip 36 from snagging on tissue as the pericardial access device 10 is advanced to the heart 20. The needle 14 includes an access port 34 in fluid communication with the needle bore 33. The access port 34 is located near the needle tip 36 and is positioned within the cavity 18 of the shaft 12. The needle bore 33 and access port 34 are adapted for slidably receiving medical instruments, for example, guidewires, and/or fluids or gases. In one embodiment, the needle 14 extends from about 0.5 to about 3 mm into the cavity 18. In one embodiment, the needle 14 extends downwardly toward the heart at an angle of from about 15 to about 60 degrees with respect to a longitudinal axis of the shaft 12.
As illustrated in
Upon completion of the procedure, the negative pressure is removed, allowing the pericardium 22 to withdraw to a normal position, disengaging from the needle tip 36 (block 110). Finally, the shaft 12 is withdrawn from the pericardium 22 (block 112), with the guidewire 38 remaining in the pericardial space 24. The guidewire 38 may be employed to facilitate the delivery of other instruments, for example, cardiac pacing leads. Alternately, rather than delivering a payload (block 108) the needle 14 may be employed to drain off excess fluid from the pericardial space 24.
In this manner, the pericardial space 24 is accessed without piercing the epicardium 26. As the needle tip 36 is in a fixed position in relation to the recessed region 18, there is no danger of over inserting the needle 14 or of the needle 14 inadvertently snagging on tissues. Furthermore, because it is unnecessary to advance the needle 14 into position after suctioning to the pericardium 22, there is no risk of dislodging the suction port 32 from the pericardium 22.
The suction lumen 210 extends from a proximal end adapted for connection to a source of suction or negative pressure (not shown) to a distal end 218 in fluid communication with a suction port 220. The suction port 220 is disposed on the shaft 202 proximal to the distal tip 216 of the shaft 202 and in particular is positioned within the circumference of the inflatable member 214, such that the inflatable member 214 generally surrounds the suction port 220. In one embodiment, the shaft 202 may include multiple suction lumens terminating at various locations within the circumference of the inflatable member 214. The shaft 202 further includes a secondary lumen 222 having a distal port 224 disposed adjacent the suction port 220 within the circumference of the inflatable member 214. Alternately, the secondary lumen 222 and the suction lumen 210 are one in the same (Not shown; see generally the embodiment of
At this point, the needle 204 is advanced through the secondary lumen 220 to penetrate the pericardium 22 and enter the enlarged pericardial space 234 (block 258), as shown in
When the inflatable member 214 is in a deflated configuration, for example, during insertion and removal, the pericardial access device 200 displays a lower profile. When inflated and after suction is applied, the inflatable member 214 defines a pericardial bleb, as is shown in
Although the secondary lumen 222 is shown in
The needle is held in position by a flange structure 308 made up of a needle flange 310 extending about a proximal portion 312 of the needle 306 and a retention flange 314 extending inwardly from an inner wall 316 of the shaft 302. An outer diameter OD of the needle flange 310 is greater than an inner diameter ID of the retention flange 314. In this manner, the needle 306 is positioned or inserted within the suction lumen 304 such that a pointed distal end 318 of the needle 306 is positioned towards an open distal end or access port 320 of the shaft 302. The needle flange 310 engages the retention flange 314 and prevents further longitudinal displacement of the needle 306 with respect to the shaft 302. However, the needle 306 is free to rotate. A secondary retention flange 322 is positioned proximal to and spaced apart from the retention flange 314. The needle flange 310 is positioned therebetween to prevent inadvertent proximal displacement of the needle 306. In other embodiments, the needle 306 includes a secondary needle flange and the needle flange 310 and secondary needle flange are disposed on opposite sides of a single retention flange 314.
As is shown in
The needle flange 310 is positioned on the needle 306 such that the distal end 318 of the needle 306 is recessed by a distance D from the access port 320 of the shaft 302, forming a cavity or recessed space 328 between the distal end 320 of the shaft 302 and the distal end 318 of the needle 306. Thus, in a similar manner as described with respect to the pericardial access device generally shown in
A pericardial access device according to any of the preceding embodiments may be used for a variety of procedures, including, for example, epicardial lead placement, cellular myoplasty, epicardial ablation, drug delivery, blind pericardial access, endoscopic pericardial access and endoscopic dissection of tissue reflections or adhesions. It can also be used for entering other spaces between anatomic tissue layers, including the peritoneum, vascular sheaths (for treatment of carotid disease or iliac/femoral artery disease) and the dura. A pericardial access system according to any of the preceding embodiments requires only a single surgical access point to locate the pericardium 22, form an enlarged region of pericardial space, and deliver a medical instrument into the pericardial space 24 without damaging the underlying tissues.
Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.