Anticoagulant Delivery Means for Aspiration Wand

FIG. 1 is a longitudinal cross-sectional view of one presently preferred embodiment of the present invention.

FIG. 2 is a fragmentary perspective view of a preferred embodiment of the suction tip of the aspiration wand of FIG. 1.

FIG. 3 is a fragmentary perspective view of the suction tip of FIG. 2, portions being broken away to reveal the annular channel.

The invention is best understood by reference to the figures wherein like parts are designated with like numerals throughout.

The anticoagulant delivery unit disclosed herein is particularly useful in conjunction with the Aseptic Suction Collection System and Method, U.S. Pat. No. 3,866,608. Of course, any suitable blood collection reservoir could be used with the illustrated embodiments of the invention. In general, blood is aspirated through a wand generally designated 10 and is delivered by blood line 11 into a suitable receptacle (not shown) for storage and later reinfusion into the patient according to acceptable techniques of autologous blood transfer.

The aspiration wand 10 includes a handle 12 and an integral probe 14. In the presently preferred embodiments of the present invention the handle 12, probe 14 and mixing chamber 16 are fabricated from medical grade plastic material so as to be easily fabricated, inexpensive, sterilizable, and disposable. Probe 14 terminates in a rounded tip 18 having ports 20 therein. The handle 12, probe 14 and tip 18 define a continuous hollow passageway 19 traversing the entire length of the wand 10. The handle 12 has a rearwardly projecting male coupling 21 onto which the conventional vacuum blood line 11 is press-fit. Probe 14 also includes a mixing chamber 16 located adjacent the tip 18. The mixing chamber 16 is, in the illustrated embodiment, a cylindrical extension of the probe 14 and is hollow to permit internal mixing of blood and anticoagulant and subsequent transport of the blood to a container (not shown).

In FIG. 1, the mixing chamber 16 is shown to be press-fit onto both the probe 14 and the tip 18. If desired, the mixing chamber can be bonded or form an integral part of the probe and/or the tip 18. The mixing chamber 16 may have any suitable configuration such as those described and claimed in the aforementioned patent application Ser. No. 514,055 filed Oct. 11, 1974. In the embodiment of FIG. 1, the mixing chamber 16 includes spiralling ribs 17 which provide for mechanical mixing of blood aspirated through port 20 with an anticoagulant delivered through tubing 24. Ribs 17 project into the interior of the pathway 19 and traverse a spiral path. Ribs 17 thus facilitate flow of the aspirated blood in a vortical manner so as to accommodate thorough mixing with anticoagulant and at the same time avoid significant pressure changes and cellular abrasion which tend to hemolyze blood cells.

Anticoagulant is preferably delivered to wand 10 near the base 30 of tip 18 and adjacent the mixing chamber 16 (see FIG. 3). While it is acknowledged that other suitable sites for delivering anticoagulant are available, this location brings the aspirated blood into immediate contact with anticoagulant and is more simple to construct. The anticoagulant is delivered through tubing 24 which is conventionally attached to a source of a suitable anticoagulant (not shown) such as heparin or Citrate-Phosphate-Dextrose (CPD). The tubing 24 is preferably attached to the exterior of device 10 along essentially its entire length so that tubing 24 is kept out of the way during surgery. If desired, the tubing 24 could be interposed through the hollow passageway 19 and anchored therein so that the open tip thereof is secured between the ports 20 and the mixing chamber 16. Further, the tubing 24 could be formed within the structure of the handle 12 and probe 14.

Referring now more particularly to FIG. 3, the mixing chamber 16 has an annular shoulder 32 against which the trailing end 30 of the tip 18 abuts. An annular forward projection 33 extends beyond the shoulder 32 into the tip 18. The tip 18 has an annular recess 34 which is larger in the axial direction than the projection 33. Thus, when the tip 18 is seated upon the projection 33 and abuts the shoulder 32, an annular channel 36 exists between the mixing chamber 16 and the tip 18. The channel 36 is open along its entire length so as to traverse the arcuate path adjacent the internal periphery of the passageway 19 where the tip 18 meets the mixing chamber 16.

From continued reference to FIG. 3, it is apparent that the anticoagulant delivery tube 24 opens at 22 directly into the channel 36. Thus, the channel 36 is caused to fill with anticoagulant and, when overfilled, will flow the anticoagulant over the surface of the passageway 19. Thus, the anticoagulant will coat the surface of the passageway 19 and significantly reduce the incidence of clot formation in the aspiration wand. Further, since the anticoagulant is admitted immediately upstream from the mixing chamber 16, the blood and anticoagulant will be promptly and efficiently mixed prior to delivery to the receptacle (not shown).

While FIG. 3 illustrates the delivery of anticoagulant adjacent from the mixing chamber, if the mixing chamber is omitted, the probe 14 can be easily configurated to accommodate direct attachment to the tip 18 so as to form a channel substantially identical to channel 36.

To aspirate blood with wand 10, the operator, generally a surgeon or his assistant, activates a vacuum source (not shown) to impose a vacuum in line 11. Even before blood is aspirated, anticoagulant will fill the channel 36 and flow over the surface of passageway 19. Thereafter tip 18 is inserted into blood which accumulates during surgery. The vacuum in line 11 draws blood through ports 20 of tip 18. Simultaneously, additional anticoagulant is delivered through the tube 24 to channel 36 where it flows into passageway 19 and is thoroughly mixed with the blood by passage over ribs 17 in mixing chamber 16. The treated blood is then transported along the passageway 19 and through blood line 11 to a suitable collection reservoir (not shown).

While the channel 36 preferably traverses an arcuate path of 360.degree. of the interior periphery of the wand 10, a shorter arc could be used. Any channel configuration which permits anticoagulant to flow over a substantial portion of the periphery of passageway 19 could be used.

It will be noted that in the described embodiment, the anticoagulant is delivered to the blood in the immediate vicinity of the perforated tip before the blood reaches the mixing chamber. According to the present invention, the blood traverses only a very short distance before it contacts the anticoagulant-treated mixing chamber and is thereafter suitably mixed with anticoagulant to greatly minimize the opportunities for clot formation. The blood aspiration system of this invention is, therefore, a simple device which greatly simplifies the aspiration and treatment of blood with anticoagulant so that the blood is then suitable for autologous blood transfusion.

The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiment is to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.