Kidney-ureter catheter unit particularly adapated to evacuate crumbled calculi

Claim 2

A kidney-ureter catheter unit particularly adapted to evacuate crumbled calculi, characterized in that it comprises: - a flexible tubular catheter (2) provided with an introduction end (2a) substantially of truncated conical form , in the vicinity of which at least a drainage hole (3) substantially extending in a radial direction is pierced; - a semi-rigid dilator mandrel (4) of tubular configuration, provided with an introduction end (4a)of truncated conical form, said mandrel (4) being longer than the catheter (2) and being slidably engageable within the latter to be brought to an insertion condition in which the introduction end (4a) thereof extends beyond the catheter's introduction end (2a); and - a semi-rigid guide element (12) of cylindrical section, exhibiting a rounded introduction end (12a) slidably engaging the dilator mandrel (4).

Claim 3

The catheter unit as claimed in claim 1, characterized in that it further comprises fastening means (5) adapted to detachably fasten catheter (2) to dilator mandrel (4) when in their insertion condition.

Claim 4

The catheter unit as claimed in claim 1, characterized in that in the insertion condition the introduction ends (2a, 4a) of catheter (2) and dilator mandrel (4) have their generators substantially in alignment.

Claim 5

The catheter unit as claimed in claim 1, characterized in that said catheter (2) is made of radiopaque material.

Claim 6

The catheter unit as claimed in claim 1, characterized in that said dilator mandrel (4) is made of radiopaque material.

Claim 7

The catheter unit as claimed in claims 1 and 2, characterized in that said fastening means (5) substantial ly consists of a spring comprising: - one fastening portion (6) provided with one gripping area (9); - a second fastening portion (7) substantially parallel to the first fastening portion (6) and exhibiting a second gripping area (10) facing the first gripping area (9); - a spring portion (8) linking fastening portions (6, 7) to each other; - a clasping portion (11) extending from the first fastening portion (6) towards a free end of the second fastening portion (7) and engageable with the latter in a removable manner to hold fastening portions (6, 7), in opposition to the action exerted by the spring portion (8), in an operating condition in which the respective gripping areas (9, 10) are spaced apart from each other by a distance shorter than the outer diameter of catheter (2) and bigger than the outer diameter of dilator mandrel (4).

Claim 8

The catheter unit as claimed in claim 6, characterized in that said spring (5) is slidably engaged along catheter (2) through first (8a) and second (11) openings obtained in the spring portion (8) and clasping portion (11) respect ively.

Claim 9

The catheter unit as claimed in claim 6, characterized in that gripping areas (9, 10) are provided with respective surface hollows (9a, 10a) of semi-circular section, which, in the operative condition, give rise to a circular opening smaller in diameter than the outer diameter of catheter (2) and bigger in diameter than the outer diameter of mandrel (4).

Claim 10

The catheter unit as claimed in claim 1, characterized in that said catheter (2) is made of plastic material comprised of polyvinyl chloride (resin) and low density polyethylene added of plasticizers and diluents.