Recessed dilator-sheath assembly and method

Claim 2

A dilator-sheath assembly for use in percutaneous entry comprising: a sheath having an external surface and one end adapted to be inserted into the body; a dilator within said sheath and having an external surface and a distal portion extending beyond the one end of the sheath so as to define a transition, said dilator having two ends and a longitudinal passageway extending between said ends, said external surface being formed to include an annular abutment surface against which said one end of said sheath abuts such that said transition from said external surface of said dilator to said external surface of said sheath is smooth, whereby said dilator shields said one end of said sheath when the dilator-sheath assembly is inserted in the body.

Claim 3

The dilator-sheath assembly of claim 1 wherein said annular abutment surface is an annular spur surrounding said dilator and contiguous to the one end of said sheath, said spur defining a recess within which said one end of said sheath is received.

Claim 4

The dilator-sheath assembly of claim 1 wherein said one end of said sheath is externally tapered.

Claim 5

The dilator-sheath assembly of claim 1 wherein said dilator is removable from the body and sheath by withdrawing the dilator through the sheath, at least one of said sheath and said dilator being made of sufficiently flexible material to allow such withdrawing.

Claim 6

A dilator-sheath assembly for use in percutaneous entry comprising: a sheath formed of flexible plastic material, said sheath being compatible for insertion within the body and having one end adapted to be inserted in the body; a dilator within said sheath, said dilator defining a longitudinal bore sized to receive a guide wire therethough and having a distal and extending beyond said one end of said sheath, and said dilator formed of flexible plastic material; and a transition defined by an increase in the outer diameter of said dilator such that the outer diameter of said dilator is approximately equal to the outer diameter of said sheath at said one end of said sheath; and wherein said transition includes an annular abutment surface formed on said dilator against which said one end of said sheath abuts such that said transition is smooth.

Claim 7

A dilator-sheath assembly for use in percutaneous entry comprising: a sheath formed of flexible plastic material, said sheath being compatible for insertion within the body and having one end adapted to be inserted in the body; a dilator within said sheath, said dilator defining a longitudinal bore sized to receive a guide wire therethough and having a distal and extending beyond said one end of said sheath, and said dilator formed of flexible plastic material; and a transition defined by an increase in the outer diameter of said dilator such that the outer diameter of said dilator is approximately equal to the outer diameter of said sheath at said one end of said sheath; and wherein said transition includes an annular abutment surface formed on said dilator against which said one end of said sheath abuts such that said transition is smooth.

Claim 8

The dilator-sheath assembly of claim 5 wherein said transition includes a continuous annular spur disposed about said dilator so that said one end of said sheath is received under said continuous annular spur.

Claim 9

The dilator-sheath assembly of claim 5 wherein said one end of said sheath is externally tapered.

Claim 10

The dilator-sheath assembly of claim 5 wherein the one end of said sheath is formed to an angle oblique to the longitudinal axis of said sheath, and further in which said transition is formed at an angle oblique to the longitudinal axis of said dilator.

Claim 15

The method of claim 10 additionally comprising the step of allowing the mold and dilator-sheath assembly to cool until the dilator-sheath assembly is sufficiently rigid to retain its shape.

Claim 16

The method of claim 11 wherein the mold has a smooth internal mold surface and wherein the forcing is accomplished, and the pressure necessary to cause the dilator material to flow is created, by inserting the dilator-sheath assembly into the mold.

Claim 17

A dilator sheath assembly comprising: a sheath having one end adapted to be inserted into the body; a dilator within said sheath and having a distal end extending beyond the one end of the sheath, said dilator having a recess within which said one end of said sheath is received whereby said dilator shields said one end of said sheath when the dilator-sheath assembly is inserted in the body; said dilator and sheath being heat formed as an assembly causing the sheath and dilator to have an exact fit and a smooth outer surface transition between them.

Claim 18

A dilator sheath assembly comprising: a sheath having one end adapted to be inserted into the body; a dilator within said sheath and having a distal end extending beyond the one end of the sheath, said dilator having a recess within which said one end of said sheath is received whereby said dilator shields said one end of said sheath when the dilator-sheath assembly is inserted in the body; said dilator and sheath being heat formed as an assembly causing the sheath and dilator to have an exact fit and a smooth outer surface transition between them.