Abstract:
The present invention contemplates an elongated surgical guide shaft for placement within a body and surgical devices containing such a guide shaft. The shaft includes both a flexible portion and a gripping portion. The gripping portion is adapted to be handled or gripped by surgical tools and is resistant to crushing. The present invention also contemplates a method for performing a minimally invasive surgery. The method includes inserting a surgical device including such a guide shaft into a patient, grasping the gripping section of the guide shaft with a surgical tool in order to aid proper placement of the guide shaft, and using the surgical device to treat the patient.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/718,912, filed on Sep. 19, 2005, the teachings of which are expressly incorporated by reference. 
     
    
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT  
       [0002]     Not Applicable  
       BACKGROUND  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates to the field of surgery and more particularly to an elongated flexible surgical apparatus having graspable sections for use in minimally invasive surgical procedures.  
         [0005]     2. Background of the Invention  
         [0006]     Medical science has, developed a wide variety of surgical devices for accessing different areas of the body and for performing various surgical procedures. Many of these surgical devices and procedures require a relatively large opening within the patient&#39;s body just to gain access into the body cavity and to the desired area of treatment. This is particularly true with surgical devices having broad and elongated shapes and configurations and when used in procedures requiring movement of the device within the patient or requiring multiple treatment locations. Improvements are continuously being sought to reduce the negative effects of any surgery, including the effects and injuries incurred when delivering the surgical device from the entry location to the treatment areas. This concern has lead to the desire to reduce such effect and further to utilize minimally invasive procedures wherever possible.  
         [0007]     The advent of minimally invasive surgical procedures has dramatically altered numerous surgical procedures and even allowed procedures never before possible. In minimally invasive surgery, trauma to the body is reduced, in part, by reducing the surgical opening and passageway required into the body cavity as well as by using specifically designed surgical devices. Thus, there is a great desire to modify existing open surgical devices for application with minimally invasive procedures and ports.  
         [0008]     Transmyocardial revascularization (“TMR”) is a procedure wherein energy is delivered to a region of the heart in order to create small channels across the wall of the heart. The procedure is typically performed in patients suffering from severe angina. TMR is performed in a surgical setting in which access to the left ventricle is typically gained through an open surgical sternotomy or a thoracotomy. With the advent of minimally invasive thoracoscopic surgical procedures in recent years, it is desirable to deliver TMR therapy minimally invasively via ports. Similar procedures are contemplated for revascularizing other body tissues. Present TMR surgical devices, however, require unique configurations that generally preclude the use of such minimally invasive ports. Moreover, present devices are subject to damage when delivered through a port due to handling by surgical instruments.  
         [0009]     The advent of smaller and smaller surgical devices, however, has lead to numerous challenges, including properly locating the surgical device at the desired location within the body and delivering a surgical treatment device to difficult to reach locations within the body. For example, during minimally invasive surgery, including TMR and related applications, a surgeon must insert an elongated shaft of the desired surgical device into the minimally invasive port and then move it to and position it at the desired location within the body cavity. Typically, the surgeon uses various thoroscopic and related tools to assist with such placement and positioning. These tools, however, can be very difficult to use in conjunction with the flexible elongated shafts and can distort, damage, and even break such devices. In addition, the flexible materials can be difficult to locate and grasp using such surgical tools.  
       BRIEF SUMMARY  
       [0010]     The present invention comprises a surgical device for treating living tissue within a body. The surgical device of the present invention includes a handle portion for gripping and manipulation by the surgeon or other user. An elongated flexible guide shaft is connected to the handle portion at its proximal end and extends outwardly into a distal portion. The guide shaft includes at least one section that is adapted for handling by a surgical tool and to be resistant to crushing and damage when handled by surgical grasping and handling tools.  
         [0011]     In another embodiment of the invention, the distal end of the guide shaft is adapted for making a contact surface with a desired region of the heart and includes a treatment assembly that is adapted for the desired treatment. The handle assembly includes an advancement mechanism to move the treatment assembly outwardly relative to the guide shaft. The advancement mechanism allows the treatment assembly to be translated along the distal portion of the guide shaft so as to translate outwardly from it and also to be retracted.  
         [0012]     The present invention further comprises a minimally invasive procedure for treating a patient. The method comprises providing a surgical device having a flexible elongated tubular guide tube with a proximal portion in connection with a handle assembly and a distal portion extending distally from the handle into a treatment tip and wherein the distal portion includes at least one gripping section adapted for being grasped by a surgical tool without effecting the integrity of the guide tube. The distal end of the guide tube is introduced into a first port placed in the patient. The guide tube is then moved by using a surgical tool to grasp a gripping section of the guide tube within the patient and positioning the treatment tip to a desired location within the patient. The surgical device is then used so as to treat the patient.  
         [0013]     The present invention further comprises a system and method of surgical myocardial revascularization of the myocardium of the heart of a patient. In this procedure, a surgical opening and preferably a minimally invasive port is created within the patient for access to the treatment area. An elongated flexible surgical apparatus configured into an insertion configuration is inserted into the surgical opening and directed into the chest cavity. The surgical apparatus preferably includes a lasing mechanism in connection with a surgical lasing tip located at the distal end of an elongated flexible guide shaft with the guide shaft including at least one section that is strengthened and adapted for handling by surgical tools.  
         [0014]     The guide tube, including the lasing tip is then guided within the patient by using surgical tools grasping the gripping section of the guide shaft and directing the lasing tip into a desired area within the chest cavity. Preferably, the surgical tools area also introduced within the body through ports. Once positioned, the heart is next irradiated with laser energy emitted from the lasing apparatus with sufficient energy and for a sufficient time to cause a channel to be formed from the exterior surface of the epicardium through the myocardium and the epicardium. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:  
         [0016]      FIG. 1  is a perspective view of an embodiment of the surgical device of the present invention; and  
         [0017]      FIG. 2  is a side view of a preferred embodiment of a section of the guide shaft of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0018]     While a variety of embodiments of the present invention are disclosed herein, one exemplary and the presently preferred embodiment of the surgical device is illustrated generally as reference number  10  in  FIG. 1 . This embodiment of the surgical device  10  is particularly suitable for procedures for treating the heart and other internal tissues, including Transmyocardial revascularization (“TMR”), biopsies, and related procedures. The device  10  is adapted for hand use and manipulation and may be held in several positions using one or both hands.  
         [0019]     A preferred method of using the device  10  of the present embodiment involves using a treatment assembly associated with the device to perforate the desired tissue, for example, the epicardium of the heart to create revascularization pathways. In TMR procedures, these pathways are typically revascularization channels which extend into myocardium and may or may not communicate with the ventricle.  
         [0020]     Referring now to  FIG. 1 , the preferred mechanical surgical device  10  includes a hand piece assembly  12  which includes a housing and a mechanism for manipulating at least a portion of a treatment assembly. Preferably the housing is molded or machined from a lightweight plastic material and defining a contoured surface  14  defining one or more finger grip indentations. Preferably, the contoured surface  14  provides tactile feedback regarding the position of the hand on the device so the physician need not look away from the medical procedure or other task at hand. The contoured surface  14  further assists the user to securely hold the hand piece without slippage in at least two different positions during either left or right handed operation of the device  10 . A neck portion  16  extends from the distal end of the hand piece  12 . In one embodiment, the neck portion is a separate component from the hand piece  12  to allow for a rotary connection. The neck portion  16  may also be constructed from a molded or machined plastic, or similar to the hand piece  12 , may be constructed from other materials such as metal or composite materials.  
         [0021]     The surgical device  10  generally includes a continuous passageway along its generally longitudinal axis for supporting a treatment assembly  18 . In the preferred embodiment for a TMR procedure, the treatment assembly  18  includes an optical fiber bundle whose proximal end is connected to a laser energy source (not shown) and distal end terminates into a treatment end or tip  22 . The treatment assembly  18  is moveable along the device&#39;s passageway, preferably using a mechanical finger slide  24  configured as part of the handle portion  12 , but may also be moveable using most any form of mechanical or electromechanical slide mechanism or may even be moved using an automated mechanism. Through movement of the treatment assembly  18 , the treatment end  22  may be extended and retracted. Alternatively, part of the treatment assembly may be fixed relative to the handle  12  with only the distal portion or even the treatment end  22  being adjustable. The present invention further contemplates a handle  12  without a passageway and a treatment assembly  18  that is generally fixed relative to the handle  12 .  
         [0022]     A flexible elongated guide shaft  20  extends outwardly from a proximal end  26  in connection with the neck portion  16  of the handle  12  into a distal portion  28  and ultimately a distal end  30 . The guide shaft  20  is an elongated tubular piece that is constructed of a flexible tubular material having at least one strengthened or gripping section  36  along the distal portion  28 . In the preferred embodiment for TMR, the guide shaft  20  is about 60 cm in length, but this length could be varied for any particular application.  
         [0023]     The guide shaft  20  includes a lumen having an opening or diameter sufficient to allow passage of the desired treatment apparatus  18 . Alternatively, the lumen may be adapted for the treatment apparatus  18  along with other devices, treatment tips or the like. Alternatively, the guide shaft  20  may include multiple lumens adapted for surgical procedures in which multiple treatment devices or passageways are required. For example, the guide shaft  20  may include two lumens, one for the treatment apparatus  18  and one for supplying an alternative treatment to the desired region. Desired treatments may include medication, pain treatment, wound healers, stem cells and the like.  
         [0024]     Preferably, the guide shaft  20  is made from a flexible stainless steel coil lined with a flexible, low friction, and surgically suitable polymer such as Teflon or PTFE. The lined coiled material is adapted to allow for passage of the treatment assembly  18  while retaining flexibility and precluding flaking or chipping of the inner lining or treatment assembly  18  passing through it. The stainless steel coil is then reinforced with an outer polymer shaft having varying rigidity. The distal portion of the elongated shaft is then preferably coated with a soft flexible polymer for enhanced gripping characteristics and to prevent flaking and chipping of the hardened sections.  
         [0025]     Preferably, the polymer shaft is made from a medical grade polyether block co-polymide polymer (“Pebax”) material providing flexibility and some strength with the external polymer layer providing a smooth surface to facilitate placement within the body and maintaining surgical cleanliness. To provide for strengthened gripping sections  36  along the guide shaft  20 , the reinforcing shaft is preferably constructed from a variable durometer Pebax material.  
         [0026]     The harder sections  36  are adapted to be crush resistant and are about 0.25 to 2.0 centimeters (“cm”) in length. In a preferred embodiment, the gripping sections  36  of the elongated shaft  20  are between 0.5 and 1.0 cm in length and are separated by more flexible sections of the guide shaft that extend approximately 0.5 to 5.0 cm in length. The crush resistant zones or gripping sections  36  can be colored, color coated, or otherwise marked to enable a surgeon to easily identify those sections  36  that are designed to be grasped with the external manipulation tools. The more flexible regions of the shaft  20  are preferably of lower durometer material than the gripping sections  36 .  
         [0027]     The hardened materials of the gripping sections  36  are adapted to prevent flaking, chipping, or gouging while being handled by the external tools. Preferably, this is accomplished by coating the external portion of the distal end  30  or the entire guide shaft  20  with a soft coating. Preferably, the coating is a soft clear Pebax. Other suitable materials may include polyurethane, Teflon, silicone, and the like. Alternatively, only the crush resistant or gripping sections  36  are coated.  
         [0028]     In the preferred embodiment shown, a stabilizing tip or cup  32  is connected to the distal end  30  of the guide shaft  20 . The cup  32  is generally cup or disc shaped and is designed to contact tissue and maintain contact of the distal end  30  on the region of tissue being treated. The stabilizing cup advantageously aligns the treatment tip in the desired orientation and in TMR procedures is adapted to ensure the treatment tip  22  enters the heart tissue at a perpendicular orientation. The stabilizing tip  32  may be constructed from generally yieldable materials such as silicone, soft elastic, rubber, or foam and may also be metallic or plastic. The stabilizing tip  32  may be part of or permanently attached to the distal end  30  of the shaft  20  or may be detachable with conventional snap-mount or screw-mount mechanisms. Different detachable stabilizing tips  32 , such as suction and drug delivery tips, may be provided to accommodate different treatment procedures as well as for use through differing access ports.  
         [0029]     The distal end or tissue contacting surface of the tip  32  may be textured to provide a gripping surface and suction may be provided at the proximal end of the hand piece to extend through the shaft  20  to further secure the stabilizing tip  26  to the tissue being treated, including the heart. The stabilizing tip  32  preferably includes a bore aligned and in connection with the lumen opening at the distal end  30  of the guide shaft  20 . In this way, the treatment assembly  18  may freely pass through the guide shaft  20  and the stabilizing tip  32 .  
         [0030]     In the preferred embodiment configured for TMR, the proximal end of the cup  32  is rigidly bonded to the distal end  30  of the guide shaft  20  and is configured with a proximal end having a diameter similar to that of the distal end  30  of the guide shaft  20 . The cup  32  tapers outwardly from the guide shaft  20  into a contact surface outer diameter of about 5 mm. The vacuum cup  32  is preferably made from a medical grade polyether, such as Pebax, or other medical grade nylon-type material that is sufficiently pliable to form a contact surface with the tissue being treated and is bonded to the distal end  30  of the guide shaft  20 . Alternatively, the cup  32  and the outer reinforcing shaft of the guide shaft  20  may be formed from a single piece of flexible plastic material such as Pebax.  
         [0031]     The present invention advantageously decreases the maximum outer diameter of the surgical device that must penetrate the patient, as well as provides increased handling capabilities. The smaller diameter facilitates use of the device  10  with smaller and minimally invasive ports.  
         [0032]     The device  10  may also be used in conjunction with other surgical components or devices to accomplish the desired surgical procedure. For example, an introducer  38  may be used along the guide shaft  20  to allow for insufflation of the patient cavity during the desired procedure. Various ports may also be used to facilitate introduction and handling of the device  10 .  
         [0033]     Referring now to  FIG. 2 , a preferred embodiment of the distal portion  26  of the guide shaft  20  is shown. This embodiment shows three gripping sections  36  between the more flexible sections of the guide shaft  20 . It should be understood that any number of gripping sections is contemplated herein, including gripping sections dispersed along the entire length of the guide shaft  20 . The invention contemplates sufficient and identifiable gripping regions or sections to allow a surgeon to properly insert the guide shaft  20  and place the treatment end  22 . The invention also contemplates the use of various materials to provide the necessary flexibility and hardness for the gripping regions  36  for an applicable procedure.  
         [0034]     During a TMR procedure using the surgical device  10  of the present invention, energy is applied to myocardial tissue of the heart by means of the treatment assembly  18  supported within the passageway extending through the hand piece  12  and further extending through the elongated flexible guide shaft  20  and out from the locating cup  32 . In the currently preferred procedure, a laser provides the energy that is directed through the treatment assembly  18  which includes a means of carrying the laser energy to the treatment tip  22 . In the preferred embodiment, the treatment assembly  18  includes a fiber optic cable to deliver laser energy to the treatment site.  
         [0035]     To facilitate a minimally invasive surgical procedure using the present surgical device  10 , including the use of ports placed in the patient, the elongated guide shaft or tube  20  is inserted into a port. Because the guide shaft  20  is flexible and without rigidity and is not steerable, the procedure requires that other instruments be used to fully insert the guide shaft  20  into the patient and to position the distal end  30  to the desired location within the patient. Surgical tools such as forceps, graspers, and similar grasping and handling tools are used to grasp a gripping section  36  located along the distal portion  28  of the guide shaft  20 . Using the surgical tools, the user can then manipulate the surgical device  10 , and particularly the guide shaft  20 , within the patient. The surgical tool or tools can be inserted into the patient through surgical incisions or preferably, ports. Similarly, a camera can be inserted into the patient to assist in locating and directing the guide shaft  20  and positioning the treatment end  22  within the patient. Once the guide shaft  20  and treatment end  22  are appropriately positioned, treatment can begin.  
         [0036]     In a presently preferred TMR procedure, the distal portion of the guide shaft  20  is inserted into the chest cavity of a patient. This insertion is preferably made through a port entry within the patient such as a thoracoport of about 5 mm in diameter. A thorascopic surgical tool or tools may then be used to grasp a strengthened section  36  of the guide shaft  20  and manipulate the distal end  30  and position the treatment end  22  to the desired location against the heart wall. The flexible nature of the guide shaft  20  advantageously allows for all portions of the heart to be accessed and treated.  
         [0037]     The surgical tools may be inserted into ports made at other locations in the patient. In addition, a camera or cameras may be used to assist the surgeon in finding and grasping the guide shaft  20  and in positioning the treatment assembly  22 . Once positioned adjacent the epicardium, the surgeon adjusts the treatment assembly  22  such that the treatment tip  30  is positioned generally perpendicular to the epicardium. Once positioned, the treatment assembly may be activated so as to treat the patient.  
         [0038]     Further details of the present invention, including various methods of using the present invention may be found with reference to the Detailed Description of Embodiment section of U.S. Pat. No. 5,713,894 issued on Feb. 3, 1998 to Murphy-Chutorian and Harman and to the Detailed Description of the Preferred Embodiment section of U.S. Pat. No. 5,976,164 issued on Nov. 2, 1999 to Bencini, et al., both of which are incorporated in their entirety herein by reference.  
         [0039]     The foregoing describes the features and benefits of the present invention in various embodiments. Those of skill in the art will appreciate that the present invention is capable of various other implementations and embodiments that operate in accordance with the foregoing principles and teachings. For example, many of the components may be made from various materials and may be interconnected in various ways. Moreover, the arrangement of an elongated guide shaft for supporting a treatment means may be accomplished by using different tubular shapes or configurations and the use of strengthened gripping regions or sections may be arranged in any number of methods and configurations. This is particularly contemplated as each surgical procedure may require a different treatment means and also differing surgical procedures and thus differing gripping section configurations and locations along the guide shaft. The handle may be made of materials other than plastic and may be configured differently to provide alternative designs. Accordingly, this detailed description is not intended to limit the scope of the present invention, which is to be understood by reference to the claims below.