TRANSSEPTAL SYSTEMS, DEVICES AND METHODS
Anatomical wall crossing systems, devices and related methods are disclosed in this patent document. A transseptal system, for example, can include a guidewire, a dilator, and a deflectable sheath configured to safely deliver a puncture needle through a septal wall associated with the fossa ovalis and into a central region of the left atrium of a heart. The dilator can include a dilator nose having a first outer diameter and a dilator beveled segment, extending proximal of the dilator nose, tapering from a second, greater outer diameter to the first outer diameter. The length and interplay of the puncture needle and the dilator nose can be configured such that the puncture needle is inhibited from bending and impinging upon the left side of the atrial septum of the heart during use. A body of the guidewire can include at least one loop segment to provide stable support in the left atrium for delivery of a diagnostic or therapeutic device along its more proximal portions. The deflectable sheath can position and align the dilator nose relative to the fossa ovalis.
1 . A method of treating a patient, comprising:
advancing a dilator located in a lumen of a sheath distally relative to the sheath, including applying a tenting force to a septal wall associated with the fossa ovalis of a heart using a dilator nose located at a distal end portion of the dilator;
advancing a tip of a needle attached to a guidewire and located in a lumen of the dilator distally relative to the dilator, including puncturing across the septal wall associated with the fossa ovalis;
advancing the dilator distally over the guidewire while maintaining the guidewire and the sheath in a fixed position, including extending a distal end of the dilator nose beyond the septal wall associated with the fossa ovalis by a distance equal to or greater than a length of the needle; and
advancing the guidewire distally through the dilator nose, including allowing deployment of the needle in a central region of the left atrium of the heart.
2 . The method of claim 1 , wherein advancing the dilator distally relative to the sheath includes manipulating an actuator located on or positioned adjacent to a handle of the sheath.
3 . The method of claim 1 , wherein, when advancing the dilator distally relative to the sheath, the tip of the needle is positioned within the dilator nose.
4 . The method of claim 1 , wherein, when advancing the tip of the needle distally relative to the dilator, a position of a hinge connecting a distal end of the guidewire and a proximal end of the needle is maintained proximal to the distal end of the dilator nose.
5 . The method of claim 4 , wherein allowing deployment of the needle in the central region of the left atrium includes allowing the hinge to bend such that an acute angle forms between the distal end of the guidewire and the proximal end of the needle.
6 . The method of claim 4 , wherein allowing deployment of the needle in the central region of the left atrium includes visualizing a position of the hinge relative to the distal end of the dilator nose, and confirming that the hinge is positioned distal to the distal end of the dilator nose.
7 . The method of claim 1 , further comprising maintaining coaxial alignment between the dilator and the sheath through engagement of a dilator alignment region, located proximal of the dilator nose, with a lumen wall of the sheath.
8 . The method of claim 1 , wherein extending the distal end of the dilator nose beyond the septal wall associated with the fossa ovalis by the distance equal to or greater than the length of the needle includes preventing the needle from impinging upon the left side of the atrial septum of the heart.
9 . The method of claim 1 , wherein advancing the guidewire distally through the dilator nose includes allowing a guidewire loop segment to form in the left atrium.
10 . The method of claim 9 , wherein allowing the guidewire loop segment to form in the left atrium includes engaging a portion of the guidewire loop segment with a left atrium lateral wall or the left side of the atrial septum.
11 . The method of claim 9 , further comprising advancing the dilator and the sheath distally over the guidewire and across the septal wall associated with the fossa ovalis, including extending a dilator bevel segment, located proximal to the dilator nose, into the left atrium followed by a dilator shoulder, located proximal to the dilator bevel segment, and a sheath distal end.
12 . The method of claim 11 , further comprising removing one or both of the dilator and the sheath from the patient and delivering a diagnostic or therapeutic device over the guidewire and across the septal wall associated with the fossa ovalis.
13 . The method of claim 1 , further comprising, prior to advancing the guidewire distally through the dilator nose, withdrawing the guidewire proximally and using the lumen of the dilator to measure pressure within the left atrium.