Vascular dilators
Inventors
Lederman, Robert Jay • Kocaturk, Ozgur • Greenbaum, Adam Brett
Assignees
Henry Ford Health System • US Department of Health and Human Services
Publication Number
US-10537718-B2
Publication Date
2020-01-21
Expiration Date
2034-10-13
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Abstract
Technology disclosed herein provides a reduced transition between the edge of a rigid vascular dilator and the distal edge of the accompanying introducer sheath. Disclosed dilators can be segmented into two or more primarily longitudinally extending parts, can have rigid circumferential or semi-circumferential leading shoulders to minimize the transition between the dilator and the sheath edge, and can contain internal recesses to allow sequential retraction of segments once the introducer sheath is delivered to a target chamber. With this technology, vascular introducer sheaths can be introduced percutaneously into a broad range of diseased target vessels and chambers with reduced damage to the wall of the vessel or chamber, and with reduced damage to the distal end of the introducer sheath.
Core Innovation
Technology disclosed herein provides a reduced transition between the edge of a rigid vascular dilator and the distal edge of the accompanying introducer sheath. The invention features dilators segmented into two or more longitudinally extending parts with rigid circumferential or semi-circumferential leading shoulders to minimize the transition between the dilator and the sheath edge. Internal recesses are included to allow sequential retraction of segments once the introducer sheath is delivered to a target chamber.
A key problem addressed is that conventional vascular introducer sheaths have a crossing profile necessarily wider than the accompanying vascular dilator, which interferes with smooth advancement into target vessels or chambers and causes tearing, particularly at the trailing edge of the sheath. This problem is driven by the sheath wall thickness, limited flexibility, and dilator rigidity, especially in large-bore systems.
The disclosed technology includes segmented dilators with parts of the tapered distal portion and shoulders configured to slide longitudinally relative to each other, allowing stages of retraction that reduce damage to vessel walls and sheath distal ends. Adjustable shoulder portions with movable mandrels enable control over radial extension, providing shielding during insertion and collapsibility during retraction to reduce damage and allow smooth withdrawal through the introducer sheath.
Claims Coverage
The patent contains several independent claims describing vascular dilators with segmented components and features allowing reduced transition and improved retraction through an introducer sheath, and methods of use thereof. The main inventive features are summarized below.
Segmented dilator with slidable longitudinal segments
A vascular dilator comprising first and second segments coupled along an interface primarily extending longitudinally, allowing the segments to slide relative to each other for selective disassembly to facilitate withdrawal through an introducer sheath. The first segment is configured to deflect radially inwardly toward the second segment during withdrawal.
Tapered distal portion with partial shoulder
The dilator has a tapered distal portion and a generally cylindrical proximal shaft, where the tapered portion includes a shoulder that extends at least partially around the circumference and radially beyond the shaft to shield the distal end of the introducer sheath.
Segmented shoulder portions with limited circumferential extent
The shoulder portion is divided between the first and second segments, each extending less than 180° circumferentially, with total shoulder circumferential extent less than 360°, sometimes 180° or less, facilitating smooth transition and controlled radial size during insertion and retraction.
Engagement restricting non-longitudinal motion
The shaft portions of the first and second segments are engaged so that longitudinal sliding is allowed but radial or lateral separation is restricted, for example via dovetail or pin-and-hole engagements.
Internal recess allowing inward deflection during retraction
The first segment has a recess in the tapered distal portion into which the distal end of the second segment deflects radially inwardly during retraction, enabling passage through the sheath lumen.
Additional third segment for full circumferential shoulder
An embodiment with a third segment coupled along two interfaces to the first and second segments, all slidable longitudinally, carrying respective shoulder portions that combine to form a shoulder extending completely around the dilator.
Nosecone tip defining distal guidewire lumen portion
The first segment comprises a fully annular distal nosecone tip defining the distal portion of a guidewire lumen through the dilator, with the second segment forming the proximal guidewire lumen portion.
Introducer sheath with beveled distal end geometry
The accompanying introducer sheath distal end has a generally constant outer diameter with an inner diameter that increases moving distally toward the sheath's distal end, facilitating inward deflection of dilator shoulders during retraction.
Method of segmented insertion and staged retraction
Method including advancing the first segment distally relative to the second segment and introducer sheath, then sequential proximal retraction of the second segment alongside the first segment shaft portion, causing distal parts of segments to deflect radially inward upon contacting the sheath distal end to permit passage, followed by retraction of the first segment, optionally with a third segment retracted prior to the first.
The claims cover segmented vascular dilators with partial or full circumferential shoulders that can deflect radially inward during staged retraction through an introducer sheath. The dilators and sheath design cooperate to minimize vessel or sheath damage during insertion and withdrawal, with methods specifying steps for advancing and retracting segments in stages while controlling radial profiles.
Stated Advantages
Reduced damage to the wall of the vessel or chamber during vascular introducer sheath insertion.
Reduced damage to the distal end of the introducer sheath during insertion and retraction.
Improved smoothness of advancement of the introducer sheath into target blood vessels or chambers.
Allows introduction of vascular introducer sheaths percutaneously into a broad range of diseased target vessels and chambers.
Documented Applications
Insertion of vascular introducer sheaths percutaneously into diseased target blood vessels or chambers.
Accessing one blood vessel from another, for example accessing the descending aorta from the inferior vena cava.
Direct transthoracic or transmyocardial entry into the heart through the heart wall, such as for prosthetic heart valve implantation.
Reducing puckering or buckling of the heart wall during direct access through the heart wall.
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