Abstract:
A method and system are disclosed for rapid placement of tubes within a body cavity that includes placing a compliant cannula over a probe tip of a cutting device until the probe tip extends beyond the cannula, incising the tissue covering body cavity to create an opening therein, inserting the probe tip of the cutting device until the cannula placed thereon extends into the incision, removing the probe tip while leaving the cannula inserted within the incision, introducing a distal end or tip of a tube into the cannula a predetermined distance, and removing the cannula over the tube while retaining the tube in position within the body cavity. The device includes a sealing portion which attaches to the body without sutures and having an opening therethrough, and a tube which passes through the opening of the seal and mates thereto without sutures.

Description:
RELATED APPLICATION  
       [0001]     This application is based on provisional U.S. Patent Application Ser. No. 60/444,345, filed Jan. 31, 2003 and having the same inventors and same title as the present application, and which is incorporated herein by reference.  
         [0002]     This application is related to U.S. patent application Ser. No. 10/______, entitled Tissue Manipulation and Incision System and Method, having partly common inventors, assigned attorney&#39;s docket number 029011-0301317 (herein referred to as the “Related Application”) and filed on even date herewith filed herewith and incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0003]     The present invention relates to methods and apparatus for performing a rapid tube thoracostomy, and more particularly relates to methods and apparatus for performing a rapid tube thoracostomy using conformable tubes and cannula.  
       BACKGROUND OF THE INVENTION  
       [0004]     A trocar generally comprises an obturator and a cannula. The obturator has a pyramid-shaped piercing tip at one end, and moves the piercing tip into tissue to form a hole to provide access to a body cavity or a target tissue. The cannula is located around the obturator. The cannula is inserted into the body cavity together with the obturator through the hole formed by the piercing tip. Such a trocar, therefore, forms a pathway in the inside of the cannula for inserting an endoscope or a surgical tool into the body cavity, by extracting or withdrawing the obturator from the cannula, which is inserted into the body cavity. Known methods of sealing the tissue to the cannula include the use of sutures and/or adhesive tape in order to maintain the position of the cannula and provide a fluid and air tight seal. However, this method fails to provide adequate barrier or an appropriate seal for fluid and/or gases. Therefore what is needed is a system and method for providing an air and fluid tight seal without the use of sutures and/or adhesive tape.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides methods and systems for safely and easily performing a rapid tube thoracostomy. Tube thoracostomy is a method for allowing the sterile drainage of fluid or air from the pleural space utilizing a semi-rigid drainage tube. In at least some implementations, the present invention also minimizes the need for exposed sharp instruments such as scalpels.  
         [0006]     More particularly, the present invention provides a chest tube installation system which includes, in an exemplary embodiment, a chest tube insertion device, a diametrically compliant cannula, a chest tube and a chest tube pneumo seal/wound dressing. The chest tube insertion device utilizes a cutter such as that disclosed in the Related Application, referenced above, and incorporated herein by reference. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0007]      FIG. 1  illustrates in perspective view generally an insertion gun, a cannula and chest tube in accordance with one aspect of the present invention.  
         [0008]      FIG. 2  illustrates, in side elevation view, in addition to the system of  FIG. 1 , a seal in accordance with one aspect of the present invention.  
         [0009]      FIG. 3  illustrates the gun of  FIG. 1  applied to an area of tissue characteristic of a patient needing aid, with the cannula on the probe of the gun.  
         [0010]      FIG. 4  illustrates the gun of  FIG. 1  inserted partly into the patient after appropriate cuts have been made.  
         [0011]      FIG. 5  illustrates the gun removed from the patient with the cannula remaining inserted into the patient.  
         [0012]      FIG. 6  illustrates the insertion of the chest tube through the cannula of  FIG. 5 .  
         [0013]      FIG. 7  illustrates the chest tube inserted into the patient through the cannula.  
         [0014]      FIG. 8  illustrates the removal of the compliant cannula over the chest tube.  
         [0015]      FIG. 9  illustrates the application of a sealing element over the chest tube.  
         [0016]      FIG. 10  illustrates the sealing of the wound with the seal over the chest tube, thus completing the chest tube installation.  
         [0017]      FIGS. 11A-11B  show in cut-away view one implementation of the gun of  FIG. 1 , with  FIG. 11B  providing a detail view of the cutting tip of the gun.  
         [0018]      FIG. 12  shows in cut-away view certain details of the implementation of  FIG. 11A .  
         [0019]      FIG. 13  illustrates in cut-away view the gun of  FIG. 11A  with the trigger at approximately mid-point.  
         [0020]      FIG. 14  illustrates in more detail an implementation of the gun of  FIG. 13 .  
         [0021]      FIG. 15A  illustrates the implementation of the gun of  FIG. 11A  with the trigger fully retracted.  
         [0022]      FIG. 15B  illustrates in detail cut-away view the cutting tip of  FIG. 15A .  
         [0023]      FIGS. 16A-16D  illustrate the eccentric nature of the cutting tip of the gun.  
         [0024]      FIGS. 17A-17D  illustrate cross-sectional view of various chest tubes, both in compressed and uncompressed views.  
         [0025]      FIGS. 18A-18E  illustrate various details of some examples of chest tubes in accordance with the present invention.  
         [0026]      FIGS. 19A-19B  illustrate perspective and cross-sectional side views of a seal in accordance with the invention.  
         [0027]      FIG. 20  illustrates an adhesive method for attachment of the chest tube assembly to a patient.  
         [0028]      FIGS. 21A-21C  illustrate, respectively, a side elevation view of a snap lock fitting for attachment of the chest tube to a patient, a cross-sectional side view, and a perspective view of the snap lock fitting itself.  
         [0029]      FIGS. 22A-22B  illustrate in cross-sectional side view the attachment of the snap lock fitting of  FIGS. 21A-21C  to a patient. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]     Referring first to  FIGS. 1 and 2 , a system for chest tube insertion in accordance with the present invention is shown generally. A chest tube insertion device  100 , which may also be thought of as a cutting and insertion gun, includes a housing  105 , a handle  110  with a trigger  125 , a probe tip  130  having a cutting tip  135  at the distal end thereof, a cannula  140 , a chest tube  145  and a seal  150 . The cutting tip  135  may be of the type described in the Related Application.  
         [0031]     Referring next to  FIGS. 3-10 , the process for inserting a chest tube according to the present invention can be better appreciated. The chest tube insertion procedure using this system is safer, faster, and easier than other known methods. Although not a required part of the present invention, clinicians considering insertion of a chest tube typically include the steps of selecting a site, preparing the patient and then draping the area, followed by anesthetizing the site. The anesthesia can be of any acceptable type; one typical approach is 5 to 15 ml of 1% lidocaine delivered through a syringe and small gauge needle.  
         [0032]     Following the foregoing preliminary steps, the chest tube insertion procedure in accordance with the present invention proceeds as follows: 
        1. Make an incision through skin to the pleural space with the chest tube insertion device, or gun,  100 . Start by placing a cannula  140  over the probe tip or shaft  130  of the device  100  until the cutting tip  135  extends beyond the cannula  140 .     2. Place the device  100  against the patient&#39;s target tissue  170  as shown in  FIG. 3 . Visually aligning the shaft  130  of the device in the desired direction. Firmly press the distal tip  135  into the skin and actuate the trigger  125 . Actuation of the trigger will initiate a cutting event, creating an incision  175 , as shown in  FIG. 4 . Each cutting event will cut approximately 1 mm in depth as long as the cutting tip is maintained appropriately against the tissue  170 . As the device  100  cuts through skin, the device  100  may be used as a blunt dissection device, and may be thought of as a blunt tip obturator.     3. Once the tip of the probe  130  extends into the pleural cavity in the desired amount, the cannula will also extend into the cavity as shown in  FIG. 4 . Withdrawal of the gun  100  from the incision  175  can be achieved while leaving the cannula  140  in place within the patient as shown in  FIG. 5 .     4. As shown best in  FIG. 6 , introduce the distal tip  600  of the chest tube  145  into the cannula  140 .     5. Advance the tube  145  until all of the transverse drain holes  700  of the chest tube  145  are within the pleural space, as shown in  FIG. 7 .     6. Withdraw the cannula  140  over the chest tube  145  while holding the chest tube  145  in place, best shown in  FIG. 8 .        
 
         [0039]     Then, as is typical of thoracostomies, the clinician will typically take the additional steps of suturing the skin on both sides of the chest tube and tying the tube in place with the tag ends of the suture; applying sterile petroleum gel over the incision to create an airtight seal and cutting notches in sterile gauze to fit around the chest tube, followed by securing the gauze and tube in place using a suitable surgical tape.  
         [0040]     From the foregoing, a method of rapidly placing a chest tube according to the invention can be appreciated. However, the chest tube insertion device  100  may be implemented in any of a variety of designs, just as the cutting tip  135  may be implemented in a variety of ways as discussed in the Related Application. Several of these implementations are described in connection with  FIGS. 11A through 15 .  
         [0041]     Referring next to  FIGS. 11A-11B  and  12 , a first implementation of the chest tube insertion device shown generally at  100  may be better appreciated. An eccentrically mounted circular blade  1  is housed inside a bearing block  2  and is attached to the bearing block  2  by an axle  6 . The blade  1  need not be an eccentrically mounted circular blade, but may instead be any of the forms shown in the Related Application. The bearing block  2  is located at the distal end of a shaft or probe  3 , which is similar to the probe  130  of  FIG. 1 . The blade  1  is also connected to the distal end of an input rod  4  by a pivot pin  5 . A compression spring  8 , is constrained at a compressed height  10 , by a flange  7  at the proximal end of the input rod  4  and a wall  9  inside the mechanism housing. The force from the compression spring  8 , translates through the input rod  4  to the eccentrically mounted blade  1  through the pivot pin  5 . The force acting on the pivot pin  5  results in a moment about the axle  6  which keeps the blade  1  recessed inside the bearing block  2  until the operator initiates a cutting event.  
         [0042]     To initiate a cutting event, the operator moves an input lever or trigger  14 , which is similar to the trigger  125  of  FIG. 1 , from a stationary position  15 , as shown in  FIGS. 11A-11B  and the more detailed view of  FIG. 12 , through an intermediate position  16  as shown in  FIG. 13  to a final position  17  shown in  FIG. 15 . As the input lever  14  is moved, it pivots about a lever axle  18 . The angular rotation of the lever  14  is translated through one segment of circular gear teeth  19  mounted concentric to the lever axle  18 , to a meshing segment of circular gear teeth  20  attached to a cam  21 . The cam  21  is allowed to rotate about a shaft  22  as it is motivated to do so by motion of the gear teeth  20 .  
         [0043]     The cam  21  profile is exaggerated through a pair of elongated members  23  which contact a momentum storage mass  25  through a matching pair of latches  26  which are attached to the mass  25  by pins  28 . The latches  26  are able to rotate about the pins  28  that connect them to the mass  25 . The mass  25  is constrained to move only longitudinally on an axis co-linear with the shaft  3 . Angular cam motion is translated to distal-to-proximal linear motion of the mass  25  as the cam  21  rotates from a stationary position  24  shown in  FIG. 11A  to a final position  29  as shown in  FIG. 15 .  
         [0044]     In the particular implementation shown, the mass  25  is moved rearward or toward the proximal end of the device  100 .  
         [0045]     Distal-to-proximal linear motion of the mass  25  causes the angled outer surfaces of the matching pair of latches  26  to encounter stationary protrusions  27 . As detailed in  FIG. 14 , the protrusions  27  act on the angled outer surfaces of the latches  26  so that the latches  26  rotate about their pivot pins  28  until they no longer contact the cam members  23 . Simultaneously, the mass  25  compresses a spring  11  from its free length  12  as depicted in  FIG. 11 , as it travels proximally, to a compressed length  13  as depicted in  FIG. 13 . Release of the latches  26  from the cam members, enable the resultant force created by compression of the spring  11  to act on the momentum storage mass  25  thereby accelerating it in a proximal to distal direction. Potential energy stored in the spring  11  at the compressed length  13  is converted to kinetic energy as the mass  25  is accelerated.  
         [0046]     The proximal to distal motion of the mass  25  causes its distal most face  30  to strike the proximal end of the rod  4 . The mass  25  and the rod  4  continue with a proximal to distal motion until the flange  7  strikes a travel limiting structure  32 . The proximal to distal motion of the rod  4  acts on the blade  1  such that it rotates about the axle  6 , which attaches the blade  1  to the bearing block  2 . As the mass  25  and the rod  4  travel proximal to distally, the blade  1  rotates about the axle  6 , which connects the blade  1  to the bearing block  2 . Depicted in FIGS.  16 A-D, as the blade  1  rotates, it emerges from the bearing block  2  from a stationary position to a fully exposed position when the rod  4  encounters the travel limiting structure  32 .  
         [0047]     As the momentum storage mass  25  travels in a proximal to distal direction it compresses a spring  36  constrained between a flange  39  and stationary internal structure  40 . Force stored in the spring  36  created by compressing the spring  36  to a pre-loaded height  38  acts on the mass  25  once its proximal to distal motion has been halted by the travel limiting structure  32 . The force generated by the spring  36  causes the mass  25  to move in a distal to proximal direction until equilibrium is achieved. With the mass  25  reset, the compression spring  8  that is in contact with the proximal end of the rod  4  acts on the rod  4  to move the rod  4  in a distal to proximal direction thereby recessing the blade  1  to a safe position inside the bearing block  2 .  
         [0048]     The operator resets the mechanism after initiating a cutting event by releasing the input lever  14 . The input lever  14  then returns to the stationary position  15  by means of a spring (not shown) in contact with the input lever  14 , causing the input lever  14  to rotate about the lever axle  18 . Motion of the lever  14  causes the cam  21  to move to its stationary position  24 . As the elongated members  23  move to their stationary positions the latches  26  attached to the mass  25  are acted on by an extension spring  41  to return the latches  26  to their position  42 . The mechanism is now reset and ready for another operator initiated cutting event.  
         [0049]     Optionally, an additional user control may be incorporated into the device  100  to hold the cutting element fully extended when actuated. This alternative control allows the clinician to optionally use the device as a sharp trocar as well.  
         [0050]     One aspect of the chest tube insertion device is that the shaft  130  is, in an least some embodiments, substantially ovate in cross section. This allows for passage of a larger bore transversely compliant cannula to be inserted between the ribs without dilating the rib cage. At room temperature, standard chest tubes are fairly diametrically compliant, across the transverse axis of the tube, and become much more compliant at body temperature. Therefore, standard chest tubes can be passed through a substantially ovate cannula. Thus, a larger chest tube can be inserted with significantly less pain to the patient. Optionally, the cannula may be pre-formed with an ovate cross section of a less compliant material.  
         [0051]     Another aspect of the device is the use of preferentially compliant chest tubes. Standard chest tubes are formed with uniform wall thickness. These tubes are formed with walls heavy enough to prevent kinking across the transverse axis of the tube due to longitudinal bending loads. When using a substantially ovate cannula, the load required to pass the circular chest tube through the cannula, can be substantially reduced through the use of a tube that is preferentially more diametrically compliant, across the transverse axis, than standard tubes.  
         [0052]     In some embodiments of the invention, it is desirable to use a generally thinner walled tube, which may for example be formed by extrusion, with walls formed with a multiplicity of longitudinal ribs, scallops or splines as shown in  FIGS. 17A-17D . The ribs may be on the inside or outside of the tube, and may take any of a wide variety of shapes. The space between the ribs form flexure zones, thus allowing the tube to be more diametrically compliant than a standard tube. Another purpose of the ribs is to provide adequate section modulus to prevent transverse kinking of the tube when bent under normal loading conditions, such as shown by the equations set forth below and shown in  FIGS. 18A-18E . Furthermore, design of interior ribs could provide patent lumens, to prevent complete shut off, even when exposed to extreme loading conditions. Additionally the ribs add sufficient section to provide adequate resistance to tensile loads.  
       Cantilever   ⁢     -     ⁢   moment   ⁢           ⁢   load       
         Modulus   section     :=       Base   ·     Height   3       12         
       Moment   :=     2   ·       deflection   ·     Modulus   Elastic     ·     Modulus   section         Length   2             
 
         [0053]     Another innovative aspect of the some embodiments of the system of the invention is the use of an elastomeric pneumo-seal, such as shown at  150  in  FIG. 2  and better seen in  FIGS. 19A-19B . The term pneumo-seal is used herein to refer to a seal that acts as a barrier to prevents the flow of fluids and gases. The pneumo-seal  150  can be formed of a compliant material with upper flange  1900  and lower flange  1905 , and may have pressure sensitive adhesive attachment areas  1910  as shown in  FIGS. 20 and 21  to adhere to and seal to the patient and the chest tube. The pressure sensitive seal or barrier formed by the pneumo-seal is accomplished without stitches or sutures. The pneumo-seal may be pre-loaded and reside on the cannula  140  or may be used as a separate device.  
         [0054]     Alternatively, the pneumo-seal device  150  may have a fitting  2200  that mates to a matching fitting integrally formed with the chest tube or, as shown in  FIG. 22B , provided as a snap-lock fitting added to the chest tube. The purpose of the fitting is to mechanically attach the tube to the patient patch and to form an air-tight seal.  
         [0055]     Alternatively, mechanical sealing ribs ( FIG. 22A ) may also replace the adhesive contacting tube. The basic configuration of the pneumo-seal  150  can also be used for other cannulations into the body such as central venous lines and other drainage tubes. Optionally, the device may be molded from a transparent material, such as Pebax, to allow visualization of the wound through the device. The advantages of the pneumo-seal device include that it is faster than faster than cutting bandages, requires no use of scissors, is faster than suturing or tying, requires no needles, does not require petroleum gel to form seal (thus allowing use of standard wound dressing tapes.  
         [0056]     It will thus be appreciated that a new and novel method of chest tube insertion has been disclosed, as well as a new and novel chest tube insertion system and components thereof. Among the advantages offered by one or more of implementations of the invention are a controlled depth of cut, 
        a retractable blade offering increasing user and patient safety, greater safety for the clinician. Having fully disclosed a variety of implementations of the present invention, it will be appreciated by those skilled in the art that numerous alternatives and equivalents exist which do not materially alter the invention described herein. Therefore, the invention is not intended to be limited by the foregoing description, but instead only by the appended claims.