Fossa ovalis penetration using probing elements
Apparatus and methods are described, including apparatus for puncturing a fossa ovalis of a heart. The apparatus includes a catheter shaped to define a catheter lumen. A puncturing element is slidably disposed within the catheter lumen, and is deployed from a distal portion of the catheter and to puncture the fossa ovalis. A probing element is deployed from the distal portion of the catheter. Upon being deployed, the probing element probes tissue near the fossa ovalis, the probing element having a first configuration thereof upon probing the tissue near the fossa ovalis. Upon probing tissue of the fossa ovalis, the probing element facilitates positioning of the puncturing element, by automatically adopting a second configuration thereof that is different from the first configuration. Other applications are also described.
1. A method for puncturing a fossa ovalis of a heart, the method comprising:
inserting a catheter into a right atrium of the heart;
advancing a distal portion of the catheter toward an interatrial septum of the heart;
deploying a first set of one or more flexible longitudinal members from the distal portion of the catheter;
probing tissue near the fossa ovalis, by moving at least one of the flexible longitudinal members of the first set along a surface of the interatrial septum;
identifying a puncture site for puncturing the fossa ovalis, in response to the at least one of the one or more flexible longitudinal members of the first set probing and contacting the tissue of the fossa ovalis;
thereafter, deploying a second set of one or more flexible longitudinal members from the distal portion of the catheter, such that at least one of the one or more flexible longitudinal members of the second set contacts the fossa ovalis, the second set not comprising any of the one or more flexible longitudinal members of the first set; and
thereafter, using a puncturing element, puncturing the fossa ovalis at the puncture site.
2. The method according to claim 1 , further comprising, following the identifying of the puncture site and before the puncturing of the fossa ovalis: by pushing against the fossa ovalis with at least one of the one or more flexible longitudinal members of the first set, the second set, or both the first and the second sets, steering the distal portion of the catheter toward the puncture site,
wherein puncturing the fossa ovalis comprises sliding the puncturing element from the distal portion of the catheter.
3. The method according to claim 2 , wherein steering the distal portion of the catheter comprises adjusting a length of a deployed portion of at least one of the one or more flexible longitudinal members of the first set, the second set, or both the first and the second sets.
4. The method according to claim 1 , further comprising, following the identifying of the puncture site and before the puncturing of the fossa ovalis, adjusting an orientation of the distal portion of the catheter, by using at least one of the one or more flexible longitudinal members of the first set, the second set, or both the first and the second sets as a pivot,
wherein puncturing the fossa ovalis comprises sliding the puncturing element:
from the distal portion of the catheter, and
through the fossa ovalis, at an angle with respect to the fossa ovalis that is determined by the orientation of the distal portion of the catheter.
5. The method according to claim 1 , wherein identifying the puncture site comprises identifying the puncture site in response to at least one of the flexible longitudinal members of the first set opposing movement of the at least one of the flexible longitudinal members of the first set from the fossa ovalis, by pressing against a perimeter of the fossa ovalis.
6. The method according to claim 1 ,
wherein deploying the first set of one or more flexible longitudinal members comprises deploying the one or more flexible longitudinal members of the first set from the distal portion of the catheter such that a deployed portion of each of the one or more flexible longitudinal members of the first set is shaped as a loop, and
wherein identifying the puncture site comprises contacting the fossa ovalis with at least one of the one or more flexible longitudinal members of the first set.
7. The method according to claim 6 , further comprising, while the at least one of the flexible longitudinal members is contacting the fossa ovalis, and before the puncturing of the fossa ovalis:
by pushing against the fossa ovalis with the at least one of the one or more flexible longitudinal members of the first set, steering the distal portion of the catheter toward the puncture site,
wherein puncturing the fossa ovalis comprises sliding the puncturing element (a) from the distal portion of the catheter, and (b) through the fossa ovalis, at the puncture site.
8. The method according to claim 6 , wherein deploying the second set of the one or more flexible longitudinal members comprises deploying the second set of the one or more flexible longitudinal members such that a deployed portion of each of the one or more flexible longitudinal members of the second set is shaped as a loop.
9. The method according to claim 1 , wherein the one or more flexible longitudinal members are radiopaque, and wherein the method further comprises using fluoroscopic imaging to view the one or more flexible longitudinal members during and following deployment thereof.
10. The method according to claim 1 , wherein deploying the second set of the one or more flexible longitudinal members comprises deploying the second set of the one or more flexible longitudinal members such that at least one of the one or more flexible longitudinal members of the second set stabilizes the catheter by pressing against a perimeter of the fossa ovalis.
11. The method according to claim 1 , wherein the first and the second sets of one or more flexible longitudinal members are arranged on opposite sides of the distal portion of the catheter.