Expandable introducer sheath
The invention relates to an introducer sheath for catheters to be inserted into a vascular system comprising a connecting valve ( 2 ) and an insertion tube ( 3 ) having a proximal portion ( 4 ) and a distal portion ( 5 ), said distal portion ( 5 ) being of reduced diameter in comparison with the proximal portion ( 4 ), and to enable its diameter to be reversibly changed the insertion tube ( 3 ) is provided with longitudinally extending expansion elements with incisions ( 11, 11′, 12 ) designed as predetermined breaking points.
1. A device to enable a catheter to be inserted into a vascular system characterized in that the device comprises an introducer sheath for the catheter into which the catheter can be inserted, said sheath comprising a connecting valve ( 2 ) and an insertion tube ( 3 ) having a proximal portion ( 4 ) and a distal portion ( 5 ), said distal portion ( 5 ) being of reduced diameter in comparison with the proximal portion ( 4 ), wherein in the introducer sheath, in order to be capable of reversibly adjusting its diameter to a larger-size catheter, the insertion tube ( 3 ) is provided with longitudinally extending first expansion elements with first incisions ( 11 , 11 ′, 12 ) designed as predetermined breaking points, said first incisions ( 11 , 11 ′) alternatively arranged on the inside and outside of the insertion tube and which start at the distal end of the proximal portion ( 5 ) and terminate adjacent the distal end ( 10 ) of the insertion tube ( 3 ).
2. The device according to claim 1 , characterized in that the first incisions ( 11 , 11 ′, 12 ) are equally spaced over the circumference of the insertion tube ( 3 ).
3. The device according to claim 1 , further characterized in that the first incisions ( 11 , 11 ′, 12 ) are designed, at least partially, in the form of slots.
4. The device according to claim 3 , further characterized by second expansion elements ( 12 ) in the distal portion ( 5 ) of the insertion tube ( 3 ), with second incisions ( 12 ) running from the distal end towards the proximal portion, and terminating at a point distal to the proximal portion, wherein the areas located between the first ( 11 , 11 ′) and the second incisions ( 12 ) constitute webs ( 8 , 9 ) of equal width.
5. The device according to claim 4 , characterized in that the first incisions ( 11 ′) and the second incisions ( 12 ) are alternately arranged in a distal area ( 7 ) of the insertion tube ( 3 ).
6. The device according to claim 5 , characterized in that the second incisions ( 12 ) originate from the distal end ( 10 ) of the insertion tube ( 3 ) and extend in the distal area ( 7 ) of said tube.
7. The device according to claim 6 , characterized in that the second incisions ( 12 ) in expanded state of the insertion tube ( 3 ) form a circumferentially extending crown of meandering webs ( 8 ) in the distal area ( 7 ).
8. The device according to claim 4 , characterized in that the first incisions ( 11 ) are provided with openings in the wall of the insertion tube ( 3 ) proximal to second incisions.
9. The device according to claim 1 or 4 , characterized in that the depth of the first and/or second incisions ranges between 25 and 95% of the wall thickness of the insertion tube ( 3 ).
10. The device according to claim 4 , characterized by the first and second incisions ( 11 ′, 12 ) in a distal area ( 7 ) of the distal portion of the insertion tube ( 3 ), forming webs ( 9 ) having a meandering configuration.
11. The device of claim 1 including said catheter.