Catheter assembly
A catheter assembly includes a catheter having a main lumen and a sub lumen and an inner needle inserted through and disposed in the main lumen and allowing blood to flow in the proximal direction of the catheter from a needle tip exposed at the distal end of the catheter. The gap between an outer peripheral surface of the inner needle and a first inner peripheral surface of the main lumen continuous with the distal end of the catheter is narrower than the gap between the outer peripheral surface of the inner needle and a second inner peripheral surface closer to the proximal end side than the first inner peripheral surface.
1. A catheter assembly comprising:
a catheter comprising a main lumen and one or more sub lumens provided separately from the main lumen; and
an inner needle extending through the main lumen; and
a deflection suppression mechanism configured to suppress deflection of the inner needle by supporting the inner needle via the catheter;
wherein the one or more sub lumens respectively communicate with one or more sub openings formed in the catheter;
wherein the catheter is configured to advance with respect to the inner needle;
wherein the deflection suppression mechanism comprises a sliding contact support portion that is in sliding contact with the catheter when the catheter advances with respect to the inner needle; and
wherein the sliding contact support portion is configured to contact the catheter at (i) a location proximal of a distal-most one of the one or more sub openings, and/or (ii) a location proximal of a step portion generated in the catheter as the one or more sub lumens are formed.
2. The catheter assembly according to claim 1 , wherein:
the deflection suppression mechanism is configured to contact the catheter at a location proximal of a proximal-most one of the one or more sub openings.
3. The catheter assembly according to claim 1 , wherein:
the main lumen and the one or more sub lumens extend parallel to each other in the catheter.
4. The catheter assembly according to claim 1 , wherein:
the step portion is a tapered portion gradually decreasing in outer diameter toward a distal direction;
the one or more sub openings are provided in the tapered portion; and
the deflection suppression mechanism is configured to contact the catheter at a location proximal of the tapered portion.
5. The catheter assembly according to claim 1 , wherein:
the one or more sub openings include a lateral opening provided in an outer peripheral surface of the catheter; and
the deflection suppression mechanism is configured to contact the catheter at a location of the lateral opening.
6. The catheter assembly according to claim 1 , wherein:
the main lumen communicates with a main opening formed in the catheter; and
the main opening and the one or more sub openings are spaced apart from each other at a distance of 17 mm or more.
7. The catheter assembly according to claim 1 , wherein:
the deflection suppression mechanism is configured to contact the catheter at a distal end side of the deflection suppression mechanism, and at a distance of 5 mm or less from a closest of the one or more sub openings.
8. The catheter assembly according to claim 1 , wherein:
the main lumen and the one or more sub lumens are partitioned from each other by a partition wall that is deformable in response to pressure.
9. The catheter assembly according to claim 1 , wherein:
the deflection suppression mechanism surrounds an entire circumference of the catheter.
10. The catheter assembly according to claim 1 , further comprising:
a catheter hub fixing and holding the catheter; and
an inner needle hub fixing and holding the inner needle;
wherein the one or more sub lumens communicate with communication paths of one or more ports provided in the catheter hub; and
wherein each of the one or more ports is configured as a connector to which a medical device is connectable.
11. The catheter assembly according to claim 10 , wherein:
the inner needle hub is configured as a housing movably accommodating the catheter hub; and
the housing comprises a slit exposing the one or more ports from an inside of the housing to an outside of the housing.
12. The catheter assembly according to claim 11 , wherein:
the housing is separable upward and downward;
the slit constitutes a part of a boundary at which the housing is separable upward and downward; and
the one or more ports protrude in a lateral direction of the housing.
13. The catheter assembly according to claim 10 , wherein:
The one or more ports protrude in an upward direction of the inner needle hub.
14. The catheter assembly according to claim 10 , wherein:
each of the one or more ports comprises:
a connecting portion to which the medical device is connectable, and
a soft tube extending between the catheter hub and the connecting portion and being softer than the connecting portion.
15. The catheter assembly according to claim 10 , wherein:
each of the one or more ports comprises:
a connecting portion to which the medical device is connectable,
a hard tube connected to the catheter hub and protruding to an outside of the inner needle hub, and
a soft tube extending between the hard tube and the connecting portion and being softer than the connecting portion,
a second inner peripheral surface that is located proximal of the first inner peripheral surface and that is spaced from the outer peripheral surface of the inner needle such that a second gap is formed between the second inner peripheral surface of the catheter and the outer peripheral surface of the inner needle, the second gap being larger than the first gap;
wherein the inner needle defines an introduction path configured to allow blood to flow to the gap between the second inner peripheral surface of the catheter and the outer peripheral surface of the inner needle for flashback confirmation.