Vascular anchoring introducer sheath
Inventors
Gittard, Shaun Davis • Hardy, Gregory James • Sigmon, JR., John C. • Newkirk, Jeremy T. • Havel, William J. • Fearnot, Neal E. • Rogers, Toby • Ratnayaka, Kanishka • Lederman, Robert L.
Assignees
National Institutes of Health NIH • Muffin Inc • US Department of Health and Human Services
Publication Number
US-12011151-B2
Publication Date
2024-06-18
Expiration Date
2037-10-25
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Abstract
Among other things, there is disclosed structure and methods for maintaining access to a location in the body while reducing or eliminating the potential for pulling an access device (e.g. a catheter) back through an opening. An introducer sheath includes a distal indented portion and a balloon, so that once placed in a desired location through tissue, the balloon can be inflated to anchor the sheath against retraction. In particular embodiments, structure and methods for accessing the pericardial cavity via the right atrial appendage are shown.
Core Innovation
The invention disclosed is a vascular introducer sheath designed to maintain access to a location in the body while reducing or eliminating the potential for pulling an access device back through an opening. The sheath includes a distal indented portion with a balloon that can be inflated to anchor the sheath against retraction once placed through tissue, such as the right atrial appendage, into the pericardial cavity.
The problem being solved arises from the risk of inadvertent pullback of introducer sheaths used in various cardiac and vascular procedures, which can cause trauma or loss of access. For example, pulling back the sheath after puncturing the interatrial septum requires repeating the puncture, causing additional trauma. Pulling the sheath back from the right atrial appendage into the heart can cause pericardial tamponade. Existing devices lack anchoring features suitable for sensitive cardiac tissues, and expansion or damage to the tissue through which the access device is placed must be avoided.
This disclosure provides a solution with an introducer sheath having a multi-layer construction including a lubricious inner layer, a heat-settable outer layer, and a coil core providing flexibility and stiffness. The distal linear portion includes an indented region with a balloon in a deflated state within the indentation. Inflating the balloon expands it coaxially past the outer diameter of the sheath to engage tissue around the access site without enlarging the opening, thus anchoring the sheath and preventing retraction. The balloon surface facing proximally is angled between 60 and 90 degrees relative to the sheath's longitudinal axis to optimize engagement with tissue. Markers positioned at the proximal edge of the indented portion aid in imaging and confirming correct placement before inflation.
Claims Coverage
The claims include one independent apparatus claim and one independent method claim, which together cover the main inventive features of the introducer sheath and its use to access the pericardial cavity via the right atrial appendage.
Multi-layer introducer sheath with coil core and balloon in indented distal portion
The sheath comprises an inner lubricious layer defining an internal lumen extending along the longitudinal axis; an outer heat-settable layer; and a coil core fixed between the inner and outer layers, extending through proximal and medial curved portions but not in the linear distal portion. The linear distal portion includes an indented portion around the entire circumference with proximal and distal edges of smaller outer diameter, and a balloon housed within the indented portion. The balloon has a deflated condition contained within the indentation and an inflated condition that extends coaxially past the maximum outer diameter of the linear distal portion, with a proximal-facing surface angled between 60 to 90 degrees relative to the longitudinal axis.
Constant inner lumen diameter and imaging markers at indented portion
The internal lumen is constant in diameter through the proximal, medial, and distal sheath portions. The sheath includes at least one radiopaque or echogenic marker abutting the proximal edge of the indented portion, positioned proximal of the proximal-most part of the balloon. Additional markers may be present at the distal tip adjacent to the lumen opening.
Fluid lumen for balloon inflation and deflation
The sheath includes a fluid lumen extending to an opening in the indented portion that allows fluid to be forced through to inflate the balloon and withdrawn to deflate the balloon. Balloon inflation does not widen the hole in the tissue.
Method for accessing pericardial cavity via right atrial appendage using the sheath
The method involves inserting the introducer sheath into the inferior vena cava, moving it into the right atrium adjacent to the right atrial appendage, and passing it through the appendage into the pericardial cavity such that the balloon is within the pericardial cavity. Imaging confirms that a marker at the proximal edge of the indented portion is beyond the right atrial appendage tissue before balloon inflation. The balloon is inflated to engage the tissue, anchoring the sheath without enlarging the hole. Devices, including a belt for treating tricuspid valve regurgitation, may be passed through the sheath while the balloon is inflated. The balloon can subsequently be deflated and the sheath disengaged and retracted.
Overall, the inventive features encompass a specially constructed introducer sheath having a balloon anchored in an indented distal portion for safe and secure tissue engagement during vascular or cardiac access, combined with imaging markers and fluid channels for controlled balloon inflation, and associated methods for safely accessing the pericardial cavity via the right atrial appendage and performing treatments through the sheath.
Stated Advantages
Prevention of inadvertent pullback of an introducer catheter within the bloodstream or cardiac tissues.
Anchoring of the sheath without enlarging or damaging the access hole or sensitive cardiac tissue.
Improved patient comfort and ease of guidance by using an inferior approach through the inferior vena cava to the right atrium.
Maintenance of access to the pericardial cavity during treatment procedures.
Facilitation of passing diagnostic or treatment devices, such as annuloplasty belts, safely through the sheath.
Documented Applications
Accessing the pericardial cavity of a patient via the right atrial appendage using the introducer sheath.
Treating tricuspid valve regurgitation by passing a belt through the sheath for placement in the atrioventricular groove.
Maintaining vascular or cardiac access for introduction of diagnostic or therapeutic devices through the sheath.
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