In a apparatus for aspirating material into an opening into a passage and along the passage, the apparatus has at least one additional opening or orifice for admitting (pre-aspirating) a fluid into the passage. The fluid facilitates aspirating the material along the passage and thus is preferably adjacent the opening through which the material enters the passage to facilitate the aspiration all along the passage. The apparatus is particularly for surgical use. In surgical uses the material to be aspirated contains blood which tends to coagulate in the passage and block it. The fluid which enters the passage through the orifice then dilutes the blood to reduce coagulation, lubricates the passage for better material flow therealong, and flushes the material along the passage.

BACKGROUND OF THE INVENTION 
Many suction devices are known for moving many different materials into and 
along a suction passage. One type of such devices which is particularly 
pertinent to the preferred embodiments of the present invention is for 
surgery. With these devices, body fluids such as blood, and tissue are 
sucked away from surgical sites both to remove the material itself, for 
example a tumor, and to keep the site clear. 
The material to be sucked along the passage of these devices in some uses, 
including surgery, is insufficiently fluid to flow well along the passage, 
and in surgery, in addition, blood, although normally fluid, naturally 
coagulates upon removal from the body and contact with foreign matter such 
as the suction passage to further tend to clog the apparatus. In surgery, 
therefore, fragments of the body tissue and coagulated blood often clog 
known suction apparatus. The time and effort for cleaning or replacing the 
apparatus to maintain its operability is always undesirable and, in 
surgery, can be critically detrimental. 
One way of reducing the clogging of suction devices which is sometimes used 
in their surgical application is to irrigate the material to be aspirated 
before it enters the suction device. The combination of the material and 
the irrigation fluid is then sucked into the device where the irrigation 
fluid facilitates the movement of the material along the suction passage. 
Another way of avoiding the clogging problem which is also used in 
surgical applications to the extent practical, is to increase the 
cross-section of the passage. In surgical applications, however, the 
extent to which the cross-section can be enlarged is limited in order to 
limit the overall cross-section of the apparatus to a practical size. The 
irrigation of the tissue prior to aspiration also must be limited in 
surgery to avoid flooding the tissue site and to avoid squirting the 
irrigation fluid in an attempt at providing the volume of irrigation fluid 
required to prevent clogging of the suction passage. Even when both the 
volume of irrigation fluid and cross-section of the suction passage are 
maximized, the suction passage in surgical suction devices still tends to 
clog excessively. 
Another way of avoiding clogging in some medical devices such as heart-lung 
machines is to introduce an anti-coagulant such as heparin into the blood. 
The resulting reduced coagulation of the blood then allows the device to 
operate without clogging. Such anti-coagulants cannot be introduced into 
an irrigation fluid for surgical operations, however, because the 
anti-coagulant will undesirably increase bleeding at the site and impair 
surgical control of bleeding and may damage the normal function of other 
tissues. 
SUMMARY OF THE INVENTION 
It is therefore an object of the invention to provide a method and 
apparatus which facilitates the movement of material, and particularly 
blood-containing material, along the suction passage of a suction device 
or aspirator. 
To this end, the invention provides a method of facilitating the movement 
of material along the passage of a suction device by introducing a fluid 
into the passage independently of the opening through which the material 
enters the passage. The fluid dilutes the material, and lubricates and 
flushes the passage so the material can be more easily sucked along the 
passage. Although the method may be useful in many known suction devices, 
it is particularly useful in surgical suction devices because the 
coagulation of the blood in the surgically removed material and the 
practical limits on the size of the suction passage often caused the 
suction passage to clog. 
With the method of the invention, however, additional fluid is introduced 
into the suction passage to dilute the blood and thus reduce its 
coagulation. The additional fluid also lubricates the passage to reduce 
the tendency of the blood to coagulate onto the walls of the passage which 
constricts and eventually blocks it. The additional fluid also helps flush 
the material along the passage. Inasmuch as the time for cleaning or 
changing surgical suction devices during surgery can be critical, 
maintaining the operability of surgical suction devices with the method of 
the invention is particularly beneficial. 
Apparatus for practicing the method comprises fluid supply extending 
through the suction device to the suction passage for supplying a fluid to 
the passage independently of an open end of the suction passage, or 
suction port, through which material enters the passage. Preferably, of 
course, the fluid supply extends through the suction device adjacent the 
suction port so as to lubricate and flush substantially all of the passage 
and dilute the material in the passage as soon as it enters the passage. 
A specific preferred embodiment of the invention comprises an 
ultrasonically vibrated surgical tool having a suction passage extending 
from the suction port or opening at one end of the tool. The fluid supply 
comprises a sleeve spaced about the tool with the suction-port end of the 
tool projecting slightly from the sleeve for use. Irrigation fluid is 
supplied between the sleeve and the tool. The sleeve is open at the 
suction port end of the tool, but at least one orifice extends through the 
tool to the suction passage just upstream of the end of the sleeve. The 
suction in the suction passage then aspirates at least some of the 
irrigation fluid through the orifice into the suction passage for the 
dilution, lubrication, and flushing functions on the material sucked into 
the suction passage through the suction port. Aspirating at least some of 
the irrigation fluid into the suction passage prior to its discharge from 
the open end of the sleeve (and subsequent aspiration through the suction 
port with the material) explains the "pre-aspirator" title which has been 
given the invention. 
Pre-aspirating irrigation fluid in this way reduces, or in the preferred 
mode, eliminates the flow of irrigation fluid from the open end of the 
sleeve. The volume of the irrigation fluid which can dilute, lubricate and 
flush the suction passage is thus not limited to an amount which will not 
flood the surgical site or a flow rate from the open end of the sleeve 
which will not squirt from the device distractingly or disruptingly to 
delicate tissues at the operating site. The invention thus avoids the 
problems of the prior art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The preferred embodiment shown in FIG. 1 is a surgical suction device 
having an aspiration tube 10 with an internal suction passage 12. The 
suction passage extends from an open end or suction port 14 through which 
body material such as tissue and blood enters the passage to a tissue 
collection vessel 16. The tissue collection vessel is sealed and connected 
to a vacuum source (not shown) by a conduit 18 to apply suction to the 
suction passage 12 in the aspiration tube 10. 
An irrigation fluid supply 20 is connected through a gravity-feed valve or 
pump 22 and irrigation conduit 24 to an orifice 26. The orifice extends 
through the aspiration tube to the suction passage 12. Irrigation fluid 
can thus flow under the control of the valve or pump 22 from the supply 20 
into the suction passage 12 to dilute, lubricate and flush the material 
which enters the aspiration tube through the suction port along the 
suction passage. 
The orifice 26 is positioned adjacent the suction port 14 so that the 
material entering the passage through the suction port is diluted and 
flushed and the passage lubricated along substantially its entire length. 
The orifice is dimensioned relative to the dimensions of the suction port 
14 and the suction from the vacuum source such that the desired level of 
vacuum is obtained at the suction port. In general, therefore, the orifice 
26 is smaller than the suction port, but the proper relative dimensioning 
of the orifice, suction port and vacuum source to obtain the desired 
suction at the suction port may be varied with the intended use of the 
device as will be readily understood by those in the art. 
FIG. 2 schematically shows another preferred embodiment which is also a 
surgical suction device, but has an ultrasonically vibrated surgical 
aspiration tool 30. Ultrasonically vibrated surgical aspiration tools are 
known; one, for example is described in the assignee's U.S. Pat. No. 
3,589,363 issued June 29, 1971 in the names of Banko and Kelman. This 
patent is incorporated by reference to provide more detailed description 
of the ultrasonically vibrated surgical aspiration tool 30. 
In general, however, the tool 30 is connected to an ultrasonic motor 32 
such as an electromagnetically excited magneto-strictive transducer. The 
motor and tool are mounted in a case or handpiece which is dimensioned to 
be held in a surgeon's hand. A sleeve 36 is connected to the handpiece and 
spaced about a portion of the tool. An end 38 of the tool 30 projects 
slightly from the sleeve 36 and the adjacent end of the sleeve is open 
about the tool. A seal 40 seals the other end of the sleeve to the tool to 
form a passage 42 for irrigation fluid between the sleeve and the tool. 
Other parts of the preferred embodiment shown in FIG. 2 are substantially 
similar to the preferred embodiment shown in FIG. 1 and are therefore 
identified with corresponding reference characters. An irrigation fluid 
supply 20' is in fluid communication via a pump or valve 22' and conduit 
24' with the passage 42 between the sleeve 36 and tool 30; the passage 42 
thus forms part of the irrigation fluid conduit 24'. A vacuum source (not 
shown) is connected through conduit 18', tissue collection vessel 16' and 
aspiration tube 10' to a passage 44 within the tool 30; the passage 44 
thus forms part of the suction passage 12'. The passage 44 has an open end 
or suction port 14' at the end 38 of the tool which projects beyond the 
sleeve. The suction passage 12' thus extends from the suction port 14' 
through the passage 44 and aspiration tube 10' to the vacuum source for 
providing suction to the passage. 
The irrigation fluid passage 42 between the sleeve 36 and tool 30 carries 
the irrigation fluid about the tool along essentially the length of the 
tool to cool the tool. The ultrasonic vibrations from the motor 32 vary 
along the length of the tool, but are at a maximum at the exposed end 38 
of the tool. The tool within the sleeve 36 thus has increasing ultrasonic 
vibrations toward the operative end 38 which, for surgical use of the 
tool, are in a range which substantially heats the tool. The irrigation 
fluid in the irrigation passage 42, however, surrounds and cools the tool. 
In addition to controlling the flow of irrigation fluid for dilution, 
flushing and lubrication carried along the suction passage 12' as before 
described, therefore, the control of the irrigation fluid flow with valve 
or pump 22' thus also provides adequate cooling fluid if the ultrasonic 
vibration design requires more fluid for cooling than for the dilution, 
flushing and lubrication of the suction passage. Fluid cooling of 
ultrasonically vibrated tools is a design consideration understood by 
those in the art and thus requires no further explanation. 
FIG. 3 is an enlarged view of the end 38 of the tool 30 shown in FIG. 2 and 
corresponding portion of the sleeve 36. As better seen in FIG. 3, the end 
46 of the sleeve 36 adjacent the tool end 38 is spaced about the tool 30. 
The irrigation fluid passage 42 is thus open-ended. Immediately upstream 
of the end 46 of the sleeve relative to the flow of the irrigation fluid 
toward the open end of the passage 42 at the sleeve end 46 is a pair of 
diametrically opposite, identical pre-aspiration orifices 26'. Irrigation 
fluid from the passage 42 can thus enter the suction passage 12' through 
the orifices 26' or be discharged from the open end of the irrigation 
passage 42 at the end 46 of the sleeve. The irrigation fluid entering the 
suction passage 12' through the orifices 26' dilutes the material entering 
the suction passage 12' through the suction port 14', flushes the material 
along the suction passage, and lubricates the walls of the suction passage 
as before described. 
In the preferred mode of operating the ultrasonic pre-aspirator shown in 
FIGS. 2 and 3, substantially all the irrigation fluid from the passage 42 
enters the suction passage 12' through the pre-aspiration orifices 26' by 
properly dimensioning the fluid supply rate, suction and pre-aspiration 
orfices 26'. To achieve a fluid flow sufficient to cool an ultrasonic tool 
vibrating at about 23 kHz with a vibrational amplitude at the tool end 38 
of about 100 microns, and to dilute, flush and lubricate body tissue and 
blood entering the suction port 14' of about 0.1 inch diameter under a 
suction of about 0.5 atmospheres without discharging irrigating fluid from 
the open end of the sleeve, the two pre-aspiration orifices are each about 
0.015 inch diameter. In an alternative mode of operating the 
pre-aspirator, however, more irrigation fluid may be supplied to also exit 
from the open end of the irrigation passage 42. The additional irrigation 
fluid can then be aspirated from the surgical site through the suction 
port 14' along with the other body material. Inasmuch as irrigation fluid 
is also supplied to the suction passage through the pre-aspiration 
orfices, however, the volume of fluid at the surgical site does not have 
to be as great as it would be without the pre-aspiration. Flooding the 
site can thus be avoided. 
Inasmuch as the irrigation fluid does not leave the device to contact body 
tissues in either of the preferred embodiments shown in FIGS. 1 and 2, 
when the latter is operated in the preferred mode with total 
pre-aspiration, the irrigation fluid may also include an anti-coagulant to 
still further reduce the coagulation of blood entering the suction passage 
through the suction port 14'. The anti-coagulant cannot affect the tissues 
at the surgical site as in prior structures because it does not leave the 
device. 
The ultrasonic vibration of the tool end 38 fragments tissue contacted by 
the tool end at a surgical site so that the tissue can be more easily 
aspirated through suction port 14'. The ultrasonic vibration of the tool 
or at least the heat thereof, however, also tends to increase the 
coagulation of blood in the tool-portion 44 of the suction passage 12'. 
The ultrasonic vibration thus increases the tendency of the aspirated 
material to block the suction passage. The ultrasonic vibration also tends 
to atomize irrigation fluid discharged at the tool end 38. The resulting 
fluid mist obscures vision of the surgical site, but is eliminated in the 
preferred mode of the pre-aspirator because irrigation fluid does not 
reach the vibrating, atomizing tool end. The pre-aspiration of irrigation 
fluid into the suction passage is thus particularly useful with 
ultrasonically vibrated surgical suction devices.