Adjustable sheath device
The disclosure generally relates to adjustable sheath devices for insertion into the body to provide intravascular access to various medical devices, involving a dynamically expandable sheath capable of expanding within the blood vessel when a medical device is passed through the sheath and retracting back to almost its original size when the medical device is removed from the sheath. Embodiments generally comprise a rigid collar and an elongated sleeve comprising a continuous elastomeric outer layer and an expandable inner layer.
1 . A retractable sheath for protecting a luminal surface of a blood vessel from the introduction of a medical device within the blood vessel, the retractable sheath comprising:
a rigid collar having an inner surface defining an opening extending through the collar, the rigid collar having attached thereto a retractable elongated sleeve having a proximal opening and a distal opening defining a luminal channel therebetween, the retractable elongated sleeve comprising two separate layers including a continuous elastomeric outer layer and an expandable inner layer discontinuous at least in part,
a discontinuous part of the expandable inner layer comprising a stiff polymeric sheet characterized as having outward annular resistance when forcibly coiled, the stiff polymeric sheet forming at least part of the expandable inner layer when coiled and positioned longitudinally within a lumen formed by the continuous elastomeric outer layer and positioned substantially in contact with a luminal surface of the continuous elastomeric outer layer,
wherein the rigid collar is attached to the retractable elongated sleeve at the proximal opening of the retractable elongated sleeve, and
wherein the expandable inner layer comprises a substantially cylindrical continuous portion terminating at the proximal opening and a discontinuous stiff polymeric sheet portion terminating at the distal opening when coiled and positioned longitudinally within the lumen formed by the continuous elastomeric outer layer and positioned substantially in contact with the luminal surface of the continuous elastomeric outer layer.
2 . The retractable sheath according to claim 1 , wherein the discontinuous stiff polymeric sheet portion is configured to coil in an overlapping arrangement in its relaxed state and to coil helically about the longitudinal axis of the retractable elongated sleeve.
3 . The retractable sheath according to claim 2 , wherein an edge of the discontinuous stiff polymeric sheet portion winds helically about the longitudinal axis of the retractable elongated sleeve.
4 . The retractable sheath according to claim 3 , wherein the discontinuous stiff polymeric sheet portion is wound about the longitudinal axis of the sheath a number of times approximately equal to the number of times the distal portion is wound plus about 0.5 to about 1.5.
5 . The retractable sheath according to claim 1 , wherein the stiff polymeric sheet comprises at least three edges, wherein at least one edge terminates in an oblique cut.
6 . The retractable sheath according to claim 5 , wherein at least two substantially opposite edges of the at least three edges intersect at a point or edge defining the distal opening and at least one of the at least two substantially opposite edges are formed by an oblique cut.
7 . A retractable sheath according to claim 1 , wherein the retractable elongated sleeve is longitudinally tapered at least partially between the proximal opening and the distal opening.
8 . A retractable sheath according to claim 7 , wherein a distal sleeve edge defining the distal opening has a circumference at least about 20% smaller than a proximal sleeve edge defining a proximal circumference of the proximal opening.
9 . A retractable sheath according to claim 8 , wherein the distal sleeve edge defining the distal opening has a circumference at least about 25% smaller than the proximal sleeve edge defining the proximal circumference of the proximal opening.
10 . A retractable sheath according to claim 1 , wherein the stiff polymeric sheet is formed from a material comprising at least one member selected from the group consisting of polyethylene, polypropylene, nylon, polyester, PTFE, co-polymers thereof or another biologically compatible polymer.
11 . A retractable sheath according to claim 1 , wherein the continuous elastomeric outer layer is comprised of an elastomeric material, the continuous elastomeric outer layer capable of being expanded upon stretching of the elastomeric material and retracted upon relaxation of the elastomeric material, and wherein the elastomeric material is capable of returning to a circumference of about 135% or less of its initial circumference once retracted.
12 . A retractable sheath according to claim 11 , wherein the continuous elastomeric outer layer capable of being expanded upon stretching of the elastomeric material to about 1.35 times or greater of its unstretched circumference.
13 . A retractable sheath according to claim 12 , wherein the continuous elastomeric outer layer comprises a thickness of about 0.1 mm.
14 . A retractable sheath according to claim 1 , wherein the continuous elastomeric outer layer is formed from a silicone material or a silicone composite material, and comprises a thickness of about 0.2 mm or less.
15 . A retractable sheath according to claim 1 , comprising a rigid introducer within the luminal channel of the retractable elongated sleeve and protruding past the distal end of the retractable elongated sleeve.
16 . A retractable sheath according to claim 1 , wherein the retractable elongated sleeve comprises a radio opaque marker.
17 . A method of use of the retractable sheath according to claim 1 comprising the steps of: obtaining the retractable sheath, passing a rigid introducer through the luminal channel of the retractable sheath, and introducing the retractable sheath into a blood vessel.
18 . A method of manufacture of the retractable sheath according to claim 1 comprising the steps of: obtaining the rigid collar, the continuous elastomeric outer layer and the expandable inner layer, attaching the expandable inner layer at the proximal opening with the rigid collar, and placing the expandable inner layer within the continuous elastomeric outer layer.
19 . A retractable sheath, for protecting a luminal surface of a blood vessel from the introduction of a medical device within the blood vessel, the retractable sheath comprising:
a rigid collar having an inner surface defining an opening extending through the collar, the rigid collar having attached thereto a retractable elongated sleeve having a proximal opening and a distal opening defining a luminal channel therebetween, the retractable elongated sleeve comprising two separate layers including a continuous elastomeric outer layer and an expandable inner layer discontinuous at least in part,
a discontinuous part of the expandable inner layer comprising a stiff polymeric sheet characterized as having outward annular resistance when forcibly coiled, the stiff polymeric sheet forming at least part of the expandable inner layer when coiled and positioned longitudinally within a lumen formed by the continuous elastomeric outer layer and positioned substantially in contact with a luminal surface of the continuous elastomeric outer layer,
wherein the rigid collar is attached to the retractable elongated sleeve at the proximal opening of the retractable elongated sleeve,
wherein the continuous elastomeric outer layer and the expandable inner layer are movable with respect to one another, and a luminal surface of the continuous elastomeric outer layer and an outer surface of the expandable inner layer are movable against each other,
wherein the retractable elongated sleeve comprises a lubricious layer or surface treatment between the luminal surface of the continuous elastomeric outer layer and the outer surface of the expandable inner layer comprising at least one member selected from the group consisting of silicone, glycerine oil, PTFE, or a hydrophilic polymer to reduce the coefficient of friction, and
wherein the expandable inner layer is integrally formed from a substantially uniform stiff polymeric material comprising a notch or cut-out between the substantially cylindrical continuous portion and the discontinuous stiff polymeric sheet portion.