Abstract:
A method of performing sinus surgery utilizes a sinus debrider instrument having an outer tubular member, an inner member rotatably disposed within the outer member and carrying a tissue cutting surface at a distal end thereof, a suction passage through the instrument for removing cut tissue from a sinus and an annular space between the inner and outer members forming a fluid passage for supplying fluid to the tissue cutting surface. The method includes the steps of positioning the distal end of the instrument at an operative site within the sinus, cutting tissue at the operative site within the sinus by rotating the tissue cutting surface, removing the cut tissue from the sinus through the suction passage and supplying fluid to the tissue cutting surface through the fluid passage to facilitate the removal of cut tissue without introducing fluid to the operative site.

Description:
This application is a continuation of patent application Ser. No. 08/752,480, filed Nov. 19, 1996, now U.S. Pat. No. 5,957,881, which is a continuation of patent application Ser. No. 08/422,903, filed Apr. 17, 1995, now U.S. Pat. No. 5,685,838. 
    
    
     FIELD OF INVENTION 
     The present invention generally relates to the field of tissue removal and more specifically relates to sinus debriders used for tissue removal during sinus surgery. 
     BACKGROUND OF THE INVENTION 
     Generally in the field of sinus surgery, arthroscopic cutting instruments have been used which instruments have encountered numerous problems, the primary one being that the instruments clog or jam from tissue buildup as there is little fluid present at the sinus surgery site unlike the abundance of fluid which occurs in the joints of a human being. Furthermore, when fluid is used with such instruments, it is excessively applied at the surgical site. The tissue jamming or clogging requires frequent cleaning or substitution of the prior art instruments which is not only time consuming thus increasing the time of the procedure as well as decreasing the number of procedures possible in a given operating room facility but also contributes to physician fatigue thus increasing the chances of error. 
     The following patents constitute representative types of prior art instrumentation directed toward tissue removal. 
     The prior art is replete with numerous surgical instruments utilizing a cutting tube mounted within an outer cutting housing, the inner cutter member being hollow and connected to a source of suction. These cutting tubes either rotate or reciprocate within the outer tube housing. Examples of such cutting instruments are shown in U.S. Pat. No. 5,324,301, issued on Jun. 28, 1994, and U.S. Pat. No. 5,286,253, issued on Feb. 15, 1994, the latter showing a similar apparatus with a toothed rotating cutter. In such instruments, the cut tissue and other severed material is generally aspirated into a chamber which has a suction removal conduit communicating perpendicularly with the axis of the tubular cutting member or flow of the surgical debris. In U.S. Pat. No. 4,983,179, issued on Jan. 8, 1991, suction is run through the instrument body to a trap in the suction source. Another U.S. Pat. No. 4,274,414, issued on Jun. 23, 1981, discloses an arthroscopic cutter having a coupling member with a central chamber which deflects fluid and tissues cut by the cutter into a cutter tube to a suction box. Another arthroscopic surgery instrument with a blunt cutter tip and similar construction is shown in U.S. Pat. No. 4,203,444, issued on May 20, 1990. A variety of cutter tips which can be used with arthroscopic surgical instruments are shown in U.S. Pat. No. 4,705,038, issued on Nov. 10, 1987, which patent also shows a suction source which extends from the cutter tube through the instrument body exiting out the rear. A cutting lipectomy device which has the suction flowing along a rigid tube parallel to the instrument body is shown in U.S. Pat. No. 4,815,462 issued on Mar. 28, 1989. 
     U.S. Pat. No. 5,403,276 issued Apr. 4, 1995 is directed toward a combined tissue removal system which uses a reciprocating cutting blade and feedback control for aspiration and irrigation circuits used in the system. Aspiration and suction is varied to the cutting instrument through a foot pedal which is controlled by the operator to set and maintain via valving and transducers the aspiration vacuum and irrigation pressure of the system. 
     Attempts to overcome clogging and jamming of these types of instruments due to collection of tissue and other materials which have been severed from the body during cutting while performing the surgical procedure has been to attempt to remove these materials so that they will not have a chance to collect in the instrument or pausing during surgery and breaking down and cleaning the instruments. Unfortunately, the cleaning of these instruments can be difficult and time consuming in a surgical environment. U.S. Pat. No. 4,108,182, issued on Aug. 22, 1978, shows a surgical instrument with a removable cutter head. The cutter head is provided with a single lumen exterior conduit leading either to the suction or the fluid source so that fluid or suction can alternately be provided along the single lumen flexible tube to the hollow cutting tube. U.S. Pat. No. 5,059,204 issued on Oct. 22, 1991 discloses an ocular guillotine cutter placed within a swagged outer needle. The cutting head has two removable parts, an infusion sleeve which is provided with a passage for transmission of fluid to the cutting site; and an aspiration sleeve provided with a passage which provides for suction which sucks material through the reciprocating cutter tube from the surgical site. The aspiration sleeve fits on the handpiece by a bayonet pin and the infusion sleeve fits over a collar of the aspiration sleeve in an interference fit. 
     The present invention has overcome the problems inherent in the prior art devices by providing a dual passage, removable manifold which can be easily removed, cleaned or replaced and a double lumen flexible tube. The cutter head body into which the manifold is mounted is also easily removed from the apparatus. 
     The double lumen flexible tube which supplies both the suction and fluid is mounted in a channel cut into the instrument body with the tube terminating at one end of the removable manifold. Thus, separate passageways for suction and fluid are provided in the invention. It should be noted that in arthroscopic surgery, there is normally a great deal of fluid present at the site of the surgery so that fluid is not required, but in sinus surgery which is the primary direction of the present invention, there is little moisture, so moisture must be supplied to keep the tissue material from clogging up the device. 
     The instrument is also provided with a nipple projection extending into the tube channel so that a surgeon can easily grasp the flexible tube and with slight finger pressure, decrease the amount of suction or the amount of fluid going to the operation site. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward a sinus cutting instrument comprising a housing, a motor mounted in the housing and a cutter head mounted to the housing. The cutter head is frustum conical shaped and defines an interior chamber, a suction passageway and a fluid passageway. A blade holder is mounted to the cutter head and is axially aligned with the interior chamber. A coupling member is mounted in the interior chamber and connects the motor and the blade member to transmit motion from the motor shaft to the blade member which is rotatably mounted in the blade holder. A removable manifold member defining separate passageways communicates with the suction passageway and the fluid passageway of the head and is formed with a connection section to hold a double lumen flexible tube providing suction and fluid to the cutter head and operation site. 
     It is an objection of the invention to provide a lightweight easily handled surgical instrument which can be readily cleaned and/or sterilized. 
     It is another object of the invention to provide an instrument which allows the surgeon to manually change the amount of fluid delivered to the surgical site and the amount of suction applied at the surgical site. 
     It is yet another object of the invention to provide a central suction chamber in the instrument which deflects tissue and cut materials directly into the suction line for later filtration of the material. 
     In the accompanying drawings, there is shown an illustrative embodiment of the invention from which these and other of objectives, novel features and advantages will be readily apparent. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the debrider apparatus; 
     FIG. 2 is a cross section of the debrider apparatus shown in FIG. 1 without its cutter assembly; 
     FIG. 3 is a cross section of the cutter head assembly with cutter assembly; 
     FIG. 4 is an enlarged side elevational view of the fluid manifold of the debrider apparatus; 
     FIG. 5 is a front elevational view of the fluid manifold shown in FIG. 4; 
     FIG. 6 is a rear elevational view of the manifold shown in FIG. 4; 
     FIG. 7 is a cross sectional view of the fluid manifold shown in FIG. 4; 
     FIG. 8 is an enlarged cross sectional view of the flexible tube; 
     FIG. 9 is a top plan view of the outer cutter tube holder; 
     FIG. 10 is a side elevational view of the cutter tube holder shown in FIG. 9; 
     FIG. 11 is an enlarged side elevational view of the end of the cutter tube holder shown in FIG. 10; 
     Figure 12 is an enlarged side elevational view partially in section of the drive coupler member; 
     FIG. 13 is a top plan view partially in phantom of the drive coupler member shown in FIG. 12; 
     FIG. 14 is a cross section view of the cutter head assembly with cutter assembly; 
     FIG. 15 is an elevational side view of the cutter tube of the cutter assembly shown in FIG. 14; 
     FIG. 16 is an enlarged view of the cutter tube tip shown in FIG. 15; 
     FIG.  16 ( a ) is a front elevational view of the cutter tube tip shown in FIG. 16; 
     FIG.  16 ( b ) is an enlarged front elevational view of the cutter tube tip shown in FIG. 16; 
     FIG. 17 is a cross section view of a cutter head assembly with an alternate cutter tube embodiment; 
     FIG. 18 is a side elevational view of the cutter tube used in FIG. 17; and 
     FIG. 19 is an enlarged side elevational view of the cutter tip of the cutter tube shown in FIG.  18 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The preferred embodiment and best mode of the invention is shown in FIGS. 1 through 19. 
     In the inventive sinus debrider apparatus  20 , the instrument is constructed with a body  30 , a cutting head assembly  50  mounted in the body  30  and a manifold  80  mounted in the cutting head assembly. 
     The body  30  which serves as the handle of the instrument is preferably in two sections formed with a motor housing cap  32  and a hand piece  34  which are mounted together and secured by screws  36 . The hand piece  34  defines a stepped cavity  35  which contains a motor  38  and a power and signal cord  22  connected to the motor. The cord  22  extends out the back of the hand piece. The motor  38  has a drive shaft  40  which extends into an axially aligned end cavity which the cutter head assembly is seated in and a corresponding stepped coupler cavity or chamber  53  formed in the cutter head assembly  50 . The drive motor  38  is adapted to rotate the blade member, or cutter or cutting tube,  110  at shearing speeds in a clockwise, counter clockwise or oscillation rotation in response to signals from an outside control foot pedal so that the tissue material is cut into discrete pieces. The rear of the motor engages silicone buffer member  42  to hold the motor in place in the cavity  35  and also to damper motor vibrations. A power source and motor control source is shown by block diagram  24  and this source is connected by a power cord  22  to the motor  38  to provide both power and signals for operating the motor in forward, reverse and oscillating manner. The power cord  22  runs through a smaller diameter section of a stepped chamber  33  cut in the motor housing cap. The hand piece  34  and motor housing cap  32  which form body  30  are provided with a groove  37  on the outer surface. The groove  37  has rounded side walls and an opening into the atmosphere which is smaller in width than the width of the flexible tube so that the flexible tube which has a diameter greater than the opening width may be forced down into the groove and held in place by the inner walls of the groove. A nipple  39  extends outward from the hand piece  34  into the groove  37  and engages the flexible fluid supply tube  26 . This nipple allows the surgeon to press down on the flexible double lumen tube  26  to reduce suction to the operation site. The groove  37  holds and retains the double lumen fluid transmission tube  26  which is in turn fastened to the fluid conduit connector end  92  of manifold  80  and at its distal end to a suction source such as a vacuum generator  23  and a fluid supply source  25  as shown in block diagram. The use of outside fluid and suction sources is well known in the art. The tube functional cross section as best represented in FIG. 8 has a liquid lumen  27  which is divided by separating wall  28  from a suction lumen  29 . 
     The cutter head assembly  50  is formed with a frustum conical body  52  defining a shoulder  54  and a rear connector tubular portion  56 . The connector portion  56  snugly fits in the end cavity of hand piece  34  in 3-pin bayonet fit with shoulder  54  abutting the planar end surface of the hand piece. The body  52  defines a fluid channel  58  and a suction channel  60  which communicate at an angle with a central stepped chamber  53 , chamber  53  being formed in axial alignment in the body  52 . A drive coupler member  62  is mounted in the stepped chamber  53  and engages motor shaft  40  on one end and cutting tube  110  on the other end so that the torque generated by the motor shaft  40  is transmitted to the cutting tube  110  or  202 . The coupler member  62  has a stepped body of A.B.S. approximately 1.6 inches in length and defines an annular cutting tube seat  64  on one end which cutting tube seat leads into and communicates with deflection chamber  66 . The cutting tube seat end is chamfered for approximately 0.03 inches at a 45 degree angle to the center axis to aid in receiving the cutting tube. The rear downstream wall  68  of deflection chamber  66  is formed into a bevel which keeps debris from the surgery from collecting and jamming in the instrument. The deflector wall  68  allows easy transmission of the tissue and other material which has been cut and removed back through suction channel  60  into the suction manifold  80 . The distal portion of the coupler member which is of a lesser diameter than the cutting tube portion is formed with an annular blind bore  70  which forms the motor shaft seat. The coupler member  62  is thus able to be seated within the coupler section of chamber  53  and easily rotate around within the chamber. Two retainer rings  72  with a viton O-ring  74  placed between the rings are mounted around the rear stepped end of the coupler member and engage the chamber walls of the body  52  defining the stepped coupler chamber  53 . A retainer ring  75  and front seal  76  are positioned in the forward stepped seal section  55  of the coupler chamber to preclude fluid from flowing back from fluid channel  58 . 
     The manifold  80  is preferably of one piece clear polycarbonate construction with a body  82  branching into a tubular fluid conduit  84  defining a fluid passage  86  and a suction conduit section  88  defining a suction passage  90 . Channels or passages  86  and  90  are angularly orientated within the body  82  forming a 30 degree bend allowing the double lumen tube  26  to be placed parallel to the handle of the instrument. Both fluid passages are separated and form a tube connector end  92  as is clearly shown in FIGS. 4 and 7. The double lumen tube  26  snugly fits over the end  92  with lumen separator wall  28  of the tube fitting into gap  94  formed in the tube connector end  92 . Each lumen of the tube is formed with a semicircle configuration with fluid lumen  27  being smaller in cross section than suction lumen  29 . 
     The cutter assembly  100  is mounted in the proximal end of coupler cavity  57  and is secured in place by an adhesive or other means. The cutter tube holder or outer tube  102  has a polished surface with a knurled distal end portion and carries within it an end piece  104  which is cut with flat edges  105  running from a point past the axis of the tube at approximately an 11 degree angle to form a tissue engagement opening  106  and a spherical end  107 . The end piece  104  is secured to tube  102  by brazing, although other means can be used. The end piece runs approximately 0.570 inches in length. The outer tube  102  has an outer diameter of 0.134 inches and an inner diameter of 0.1150 inches. Mounted inside the outer tube  102  is a cutting tube  110  which has a sharpened cutting tip  112  and knurled distal end portion  114 . The cutting tube defines a lumen  111  therethrough communicating between a tissue cutting surface  109  at distal cutting tip  112  and deflection chamber  66  adjacent the proximal end of the cutting tube. The cutting; This tube is seen in FIGS. 15,  16 ,  16 ( a ),  16  ( b ). The cutting tip  112  is ground flat, as shown at  113  in FIGS.  16 ( a ) and  16 ( b ); 0.007 inches deep and has a closed spherical end  116 . The cutting tube  110  has an outer diameter of 0.1149 inches or a diameter which is smaller but of close tolerance with the inner diameter of the outer tube with the end mounted in coupler member being knurled so that it is firmly held in the coupler member. 
     An alternate embodiment of the invention is shown in FIGS. 17 through 19. In this alternate embodiment, the instrument construction is identical with that previously disclosed with the exception that the cutter tube  202  is provided with a cutting tip  204  having a plurality of teeth  206  with slightly curved sides and rounded bottoms, the crest of the teeth extending above the axis of the cutter tube  202 . 
     In operation, the instrument is positioned to cut tissue with the suction and fluid modes activated. The cutter blade is activated by a foot switch and the surgeon increases or decreases the fluid to the surgical site by depressing the flexible tube so that the top lumen  27  of the double lumen tube is constricted reducing fluid flow. Alternatively, suction is reduced by depressing the flexible tube over nipple  39  to constrict the suction lumen  29  and reduce suction from the site. Thus, fluid or suction can be manually controlled by the surgeon&#39;s hand while rotation of the blade in either direction or an oscillating motion is controlled by a foot pedal. 
     In the foregoing description, the invention has been described with reference to a particular preferred embodiment, although it is to be understood that specific details shown are merely illustrative, and the invention may be carried out in other ways without departing from the true spirit and scope of the following claims.