AORTIC WALL REINFORCING SYSTEM
TECHNICAL FIELD
This invention relates to a method and a system to treat aneurysms, aortic dissections or aortic injuries.
BACKGROUND
Aortic dissection is a form of aneurysm in which, through a small tear in the intima of the aorta, blood enters between layers of the aortic wall, resulting in the formation of a blood-dilated sac between the layers of the aortic wall which is referred to as a false lumen. The false lumen may extend any distance proximally or distally from the entry point and reenters the true lumen of the aorta again.
Aortic dissection is a lethal condition. In a type - A (ascending aorta involved) without treatment the mortality rate is almost 80% by the end of the 2nd week and emergency surgical replacement with a synthetic graft is indicated. This carries a 50- day mortality rate of 25% in experienced centers.
In type -B (descending aorta involved) the mortality of aggressive surgical treatment is higher compared to the optimal medical treatment which is allowing one - year survival rate of 80 - 90%, but the long - term survival is suboptimal because of aorta related complications and does not exceed 50% in five years.
The introduction of non-surgical thoracic endovascular repair intervention while cultivating hopes for at least partial replacement of surgical and medical forms of treatments failed to change the short, intermediate, or long-term survival having also additional problems. Long term a pressurized false lumen tends to expand and become aneurysmal, coverage of entry points along the dissection by stent graft contains the risk of local ischemia or paraplegia due to obstruction of vital branch vessels. Of course, the main problem of finding aortic wall healthy tissue to secure an implant is unsolved.
In the open - chest surgery many problems, difficulties and complications arise from the fact that aortic surgeries require cessation of blood circulation, at least in the excised aorta segment, where vessels nourishing vital organs like brain take origin from.
The goal of a treatment would be 1. Removing or sealing the entry point. 2. Removing or collapsing the false lumen, without disturbing the vessels that originate from the dissected aortic segment. All this cannot be accomplished with the current methods and tools.
DISCLOSURE OF THE INVENTION
SUMMARY
Throughout the text and the descriptions of the drawings the term proximal means closer to the operator, the term distal means farther from the operator.
Throughout the text and the descriptions of the drawings the term stent and the term endoprosthesis have the same meaning.
Some embodiments disclosed herein relate to a method of stabilizing the aorta wall, by endoluminally advancing a tubular prosthesis as a stent or cylindrical mesh or a stent-graft, this prosthesis in the true lumen couple to aortic wall by a plurality of fasteners implanted via an open chest, each applied fastener with two wide ends, one end in the aorta true lumen attaching the inner surface of the prosthesis, the other wide end attaching the outer surface of the aorta wall, the wall of the prosthesis and all the layers of the aorta entrapped and appropriately compressed between the two fastener ends.
Some embodiments disclosed herein relate to a method of treating an aortic dissection and collapsing the false lumen comprising placing a support structure in the true lumen to maintain the patency of the true lumen and placing connectors circumferentially to aorta coupling all the layers of the aorta to the support structure inside the aorta.
Some embodiments disclosed herein relate to a system to treat an aortic dissection, the system comprising a support structure like a tubular mesh for deployment in a true lumen of an aorta, the tubular mesh, integrated to aortic wall by fasteners, applied via open chest.
In embodiments disclosed herein, the prosthesis and the aorta layers are entrapped between the wide ends of fasteners. One end, the distal, in contact with the internal surface of the prosthesis, the other, the proximal, in contact with the outer surface of the aorta.
In embodiments disclosed herein, each fastener provides two ends and a shaft between them. The distal end is alternating between a collapsed state for delivery, with a sharp configuration to pierce the tissues, and an expanded state once in the lumen of the prosthesis. The proximal flattening or base of each fastener in a realization of the invention is wider than the distant. The aortic wall may be trapped between the net-stent that runs the entire inner surface of the aorta and the proximal wide ends of the fasteners that cover most of the outer surface of the aorta.
In embodiments disclosed herein, the stent-fastener system copes with the pressures on the aortic wall, while the aortic wall serves the sealing
SHORT DESCRIPTION OF THE DRAWINGS
Fig. 1 illustrates a dissected thoracic aorta with an endoprosthesis deployed within the true lumen
Fig. 2 is showing the endoprosthesis of the Fig. 1A secured to aortic wall by fasteners.
Fig.3 shows a fastener during its application
Fig. 4 shows a fastener that has penetrated the aortic wall and the stent wall.
Fig. 5 shows a fastener
Fig. 6 illustrates an applied fastener.
Fig.7 illustrates a stent-fastener system applied to a dilated aortic arch.
DETAILED DESCRIPTION OF THE DRAWINGS
Fig.1 is schematically showing a dissected thoracic aorta (1) with a true lumen (11) and a false lumen (12). Inside the true lumen (11), a tubular network implant (2) has been deployed through wire - catheter guidance (21).
Fig.2 shows connectors (3) that connect the outer walls of the aorta (13) to the inner walls of the aorta (14) and the wall of the mesh implant (23), eliminating the false lumen by squeezing them (13), (14) and (2), between their two ends (36), (37).
Fig. 3 shows a fastener upon apply, piercing the walls of the aorta (13), (14), penetrating the false aortic lumen (12), consisting of an elongate stem (31), which terminates at an acute end (32), an elongate push rod (35), that is sliding inside the stem (34), the push rod (35) has a proximal handle (39) and a base (37) at its distal end in which a compressible material (38) is provided.
Fig. 4 shows schematically a fastener whose end (32) is inside the true lumen (12) and the lumen (22) of the endoprosthesis (2), the push rod (35) has pushed the material (38) that has developed forming a wide wedge that remains firmly attached to the end of the connector. Fig. 5 shows a fastener whose stem (31) has a dent (33) on its outer surface through which it is connected to the proximal base (39) by a ratchet-toothed mechanism, the proximal base (36), has slid one way to the distal along the dentition (33), the layers of the aortic wall (13), (14) and the stent wall (2) trapped and compressed between the expanded material (38) and the proximal base (36). The pushing rod (35) is pulled while the proximal base (36) is pushed, to attach to the stem (31) by a locking mechanism (40).
Fig. 6 illustrates an applied connector. The connector has two flattened ends and an axis that connect them. The compression of the endoprosthesis wall (23) and the aortic walls (13), (14), between the flattened ends, has eliminating locally the false lumen (12). The connector elements closer to the proximal base (36) are cut off.
Fig. 7 shows a stent-fasteners system applied to a dilated aortic arch (15). The proximal bases (36) in this realization are wider than the distant. The aortic wall is trapped between the net-stent (23) that runs the entire inner surface of the aorta and proximal bases (36) of the connectors that cover most of the outer surface of the aorta. The stent-connector system copes with the pressures on the aortic wall while the aortic wall serves the sealing.