Abstract:
Methods and apparatus for a surgical retractor include a ring, a plurality of flexible straps connected to the ring, a patch of hook or loop material connected to each strap, a coordinating patch of hook or loop material connectable to the patient&#39;s skin or the surgical drape. The flexible straps of the surgical retractor may be frangibly connected together. LEDs molded into the distal end create a light source to illuminate the surgical site. The ring may take several forms including a flexible or adjustable ring and an inflatable bladder. The ring of the surgical retractor is inserted into the surgical incision, a patch of loop fastener is attached to the patient, a set of straps connected to the ring are pulled outward and the hook portion is applied to the loop portion to hold the incision open. The retractor is useable for thoracic and other types of surgery.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to apparatus and methods for atraumatically retracting tissue. In particular, the present invention creates and maintains an opening through soft tissue. 
       BACKGROUND OF THE INVENTION 
       [0002]    Surgery on the heart is one of the most commonly performed types of surgery that is done in hospitals across the U.S. Cardiac surgery can involve the correction of defects in the valves of the heart, defects to the veins or the arteries of the heart and defects such as aneurysms and thromboses that relate to the circulation of blood from the heart to the body. In the past, most cardiac surgery was performed as open-chest surgery, in which a primary median sternotomy was performed. That procedure involves vertical midline skin incision from just below the super sternal notch to a point one to three centimeters below the tip of the xiphoid. This is followed by scoring the sternum with a cautery, then dividing the sternum down the midline and spreading the sternal edges to expose the area of the heart in the thoracic cavity. This technique causes significant physical trauma to the patient and can require one week of hospital recovery time and up to eight weeks of convalescence. This can be very expensive in terms of hospital costs and disability, to say nothing of the pain to the patient. 
         [0003]    Recently, attempts have been made to change such invasive surgery to minimize the trauma to the patient, to allow the patient to recover more rapidly and to minimize the cost involved in the process. New surgical techniques have been developed which are less invasive and traumatic than the standard open-chest surgery. This is generally referred to as minimally-invasive surgery. One of the key aspects of the minimally invasive techniques is the use of a trocar as an entry port for the surgical instruments. In general, minimally invasive surgery entails several steps: (1) at least one, and preferably at least two, intercostal incisions are made to provide an entry position for a trocar; (2) a trocar is inserted through the incision to provide an access channel to the region in which the surgery is to take place, e.g., the thoracic cavity; (3) a videoscope is provided through another access port to image the internal region (e.g., the heart) to be operated on; (4) an instrument is inserted through the trocar channel, and (5) the surgeon performs the indicated surgery using the instruments inserted through the access channel. Prior to steps (1)-(5), the patient may be prepared for surgery by placing him or her on a cardiopulmonary bypass (CPB) system and the appropriate anesthesia, then maintaining the CPB and anesthesia throughout the operation. See U.S. Pat. No. 5,452,733 to Sterman et al. issued Sep. 26, 1995 for a discussion of this technique. 
         [0004]    While this procedure has the advantage of being less invasive or traumatic than performing a media, sternotomy, there are numerous disadvantages to using trocars to establish the entry ports for the instruments and viewscope. For example, the trocars are basically “screwed” into position through the intercostal incision. This traumatizes the local tissues and nerve cells surrounding the trocar. 
         [0005]    Once in place, the trocar provides a narrow cylindrical channel having a relatively small circular cross-section. This minimizes the movement of the instrument relative to the longitudinal axis and requires specially-designed instruments for the surgeon to perform the desired operation (See, e.g., the Sterman patent U.S. Pat. No. 5,452,733). In addition, because of the limited movement, the surgeon often has to force the instrument into an angle that moves the trocar and further damages the surrounding tissue and nerves. The need to force the instrument causes the surgeon to lose sensitivity and tactile feedback, thus making the surgery more difficult. The surgical retractor of this invention is designed to reduce the trauma to the patient in providing access to the internal region, to reduce the trauma to the patient during surgery, to provide the surgeon with greater sensitivity and tactile feedback during surgery, and to allow the surgeon to use instruments of a more standard design in performing the non-invasive surgery. 
         [0006]    Other less invasive surgical techniques include access to the region of the heart to be corrected by anterior mediastinotomy or a thoracotomy. In a mediastinotomy, an incision is made that is two to three inches in length of a parasternal nature on the left or the right of the patient&#39;s sternum according to the cardiac structure that needs the attention in the surgery. Either the third or the fourth costal cartilage is excised depending on the size of the heart. This provides a smaller area of surgical access to the heart that is generally less traumatic to the patient. A thoracotomy is generally begun with an incision in the fourth or fifth intercostal space, i.e. the space between ribs 4 and 5 or ribs 5 and 6. Once an incision is made, it is completed to lay open underlying area by spreading the ribs. A retractor is used to enlarge the space between the ribs. 
         [0007]    At the present time, when either of these techniques is used, a retractor is used to keep the ribs and soft tissues apart and expose the area to be operated on to the surgeon who is then able to work in the surgical field to perform the operation. 
         [0008]    Major disadvantages of these systems include their limited positioning, complexity, and trauma to the surrounding tissue. It has now been discovered that the shortcomings of the retractors that are known in the prior art can be overcome with a new design as set forth in the following description. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    In general, the present invention provides a surgical retractor to allow improved access through a surgical opening through the tissue of a patient. The retractor includes a flexible ring, a plurality of flexible straps connected to the flexible ring, and a connector for attaching the end of the flexible strap to a support surface, such as a patient&#39;s skin, a surgical drape and a piece of surgical equipment. The connector may take the form of an adhesive patch on the flexible strap. Alternately, the connector may be a patch of hook or loop material connected to a surface of each of said plurality of straps and a coordinating patch of hook or loop material connectable by adhesive to the support surface. 
         [0010]    The diameter of the flexible ring of the surgical retractor may be adjustable. The adjustment of the ring may be achieved with a ratchet mechanism. 
         [0011]    One embodiment of the ratchet mechanism is spring loaded and may including: a plurality of openings extending into said flexible ring; an arm having an end sized and configured to extend into said plurality of openings, said arm having an engaged position wherein said end of said arm is located within one of said plurality of openings and a released position wherein said end of said arm is outside all of said plurality of openings; and a spring configured to bias said arm towards said engaged position. 
         [0012]    The flexible straps of the surgical retractor may be frangibly connected together. One version of the connection is created by a narrowed portion of the strap material. The straps and sleeve of the surgical retractor are formed of a soft, resilient material, such as silicone material. 
         [0013]    The flexible straps of the surgical retractor may be constructed of a soft, resilient material, such as silicone, which provide an atraumatic barrier between the ribs and soft tissues adjacent to the incision site. This reduces the amount of trauma to the ribs and soft tissues caused by various surgical instruments (ie. rib spreaders, surgical tools, etc) 
         [0014]    One embodiment of the surgical retractor includes a light source molded into said flexible ring. The light source may take the form of a plurality of LEDs. 
         [0015]    In one embodiment, the flexible ring includes an inflatable bladder. A pneumatic line may be attached to said inflatable bladder. 
         [0016]    An embodiment of the surgical retractor has a flexible ring that is approximately round. 
         [0017]    One embodiment of the surgical retractor includes a malleable flange extending from a distal end thereof. 
         [0018]    A method of using a surgical retractor in a surgical incision, includes the steps of: inserting a distal end of the surgical retractor into the surgical incision; causing a ring located on the distal end of the surgical retractor to open to a deployed configuration; placing a plurality of a first part of a coordinating fastener around the surgical incision; pulling a plurality of straps connected with the ring and having a second part of said coordinating fastener such that said second part of said coordinating fastener is connected with said first part of said coordinating fastener. 
         [0019]    The method may also include the step of performing a surgical procedure through a passageway extending through the surgical retractor. The surgical procedure may include CABG, valve repair, valve replacement and/or ablation. 
         [0020]    One surgical procedure using the surgical retractor is a cardiac ablation procedure. In the procedure two surgical retractors are used in two thoracic incisions located on an opposite side of the sternum. 
         [0021]    A method including stretching the straps, thereby providing additional force against tissues forming an edge of the surgical incision. 
         [0022]    An embodiment where the parts of the coordinating fastener are hook and loop fastener material and the straps of the surgical retractor are repositioned. 
         [0023]    A method includes the step of inflating an inflatable bladder which forms the ring. 
         [0024]    A method includes the step of bending outward a malleable flange extending from a distal end of the surgical retractor. 
         [0025]    A further method is performed by pulling the straps different amounts to create a non-round passageway. 
         [0026]    Yet a further method is performed by pulling the straps approximately the same amount to create a generally round passageway. 
         [0027]    The present invention can be used to provide tissue retraction and expand access openings by means of the strength and elastic properties of the materials used to manufacture the retractor. The present invention is also configured to be couplable with an adjustable surgical retractor with blades to be inserted into the patient cavity for large expansion against opposing thoracic structures while providing atraumatic contact with those anatomical structures. 
         [0028]    The present invention provides the ability to function to retract tissues, without significant expansion of the incision, but also to enlarge the size of the incision, a function that is provided by the tear strength of the silicone or the ability to combine it with an adjustable surgical blade. 
         [0029]    The present invention provides the ability to adjust the tensioning of the straps even after initial deployment through the use of the hook and loop material. This may be necessary when a surgeon needs to enlarge the incision to gain better access to the surgical site. Competitive devices use an adhesive that does not allow for repositioning subsequent to initial deployment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is a top perspective view of the atraumatic tissue retraction device. 
           [0031]      FIG. 2A  is a top perspective view of the atraumatic tissue retraction device in use. 
           [0032]      FIG. 2B  is a top perspective view of the atraumatic tissue retraction device with the straps extended farther outward. 
           [0033]      FIG. 3  is a top perspective view of the atraumatic tissue retraction device with the straps extended asymetrically. 
           [0034]      FIG. 4  is a side perspective view of the atraumatic tissue retraction device having an inflatable bladder. 
           [0035]      FIG. 5  is a close up view of a ring diameter adjustment mechanism for the atraumatic tissue retraction device. 
           [0036]      FIG. 6  is a close up view of lighting integrally molded into the base of the atraumatic tissue retraction device. 
           [0037]      FIG. 7  is a side perspective view of the atraumatic tissue retraction device with flanges extending from the bottom ring. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]      FIG. 1  is a top perspective view of the atraumatic tissue retraction device  10 . The atraumatic tissue retractor  10  is a device used to keep the field of view of a thoracotomy, sternotomy, or other surgical portal clear of soft tissues, as well as limit or prevent trauma to the ribs and other soft tissues. The device includes a sleeve  12  with an elastic or flexible ring  14  in the lower or distal end. The ring  14  may be formed of any resilient or elastic material, such as Nitinol, other metals, and plastics. The ring  14  may be adhered, bonded, overmolded into or otherwise connected to the base of the sleeve  12 . The sleeve  12  is divided into a multiplicity of straps  16 . Any suitable number of straps  16  may be used, preferably from three to twenty, more preferably in the range of four to fourteen and most preferably from six to ten. In the embodiment shown, eight straps  16  are used. Any soft resilient, flexible material may be used to form the sleeve. One suitable material is silicone. Other possible materials include, but are not limited to low durometer polyurethane, nitrile, natural rubber, or low durometer polyvinylchloride. 
         [0039]    A piece of hook or loop material  18  is adhesively bonded or otherwise attached to each strap  16 . Included with the device  10  is the coordinating piece of hook or loop material  20  with an adhesive back, as seen in  FIGS. 2A ,  2 B and  3 . In the embodiment shown, a set of eight hook pads  18  are adhesively bonded to the straps  16  and eight mating loop pads  20  are attached to the user, the drape or another nearby stable support structure in the surgical field. In the embodiment shown, the straps  16  include holes  22  at the proximal end to allow the user to easily grip the strap  16  and/or hook the strap  16  with an instrument or to a nearby structure. 
         [0040]    To use the device  10 , the user peels the backing off of the loop pad  20 , thereby exposing an adhesive and places it onto the patient&#39;s chest, other tissue, surgical drape or other nearly support adjacent to the incision as seen in  FIG. 2 . The ring  14  of the retractor  10  is then folded or deformed and pushed into the incision. When inserted into the incision, the ring  14  springs back to shape and anchors the distal end of the retractor  10 . The eight straps  16  are then pulled away from the incision and adhered to the loop pads  20  via the hook pads  18  to retract the soft tissues. In this manner, the retractor  10  has created and/or maintains an opening and passageway to the surgical site. The distal portion of the straps  16  or the sleeve  12  portion above the ring  14  also protect the tissue from the surgical instruments as they are passed into and out of the passageway. 
         [0041]    The present invention is particularly suited for thoracic surgery. In cardiac surgical procedures, the surgical retractor  10  is inserted into at least one incision into the chest to provide access for a surgical procedure, such as CABG, valve repair/replacement and/or ablation procedures. A preferred method is for use in cardiac ablation procedures with one retractor  10  in each one of two thoracic incisions on opposite sides of the sternum. The straps  16  being formed of silicone allow the retractor  10  to provide positive traction to the surrounding tissue and to atraumatically contact and retract the thoracic structures and nerves during any of these procedures. 
         [0042]    In use, the surgical retractor  10  has several advantages over typical retractors. The retractor  10  is able to retract tissues, without significant expansion of the incision or to enlarge the size of the incision, if needed. This function is created by the tear strength of the silicone. The versatility of the device  10  is further increased through the use of the hook and loop material. This fastening approach allows for adjustment and re-tensioning of the straps during the procedure. 
         [0043]    For ease of use, the straps  16  may be connected along their edges  24  to create the elongated, sleeve  12  structure for initial deployment. The connection  26  between the straps  16  may be formed of a frangible connection  26  that the user may pull apart if desired. In the embodiments shown, the frangible connection  26  is created by molding a narrowed or necked down portion of the strap  16  material. Prior to or during use, the user can easily tear along this weakened portion  26  to separate the strap  16  along as much of the length as desired.  FIGS. 2A and 2B  show the same embodiment of the retractor  10  in place in a patient in two different configuration. In  FIG. 2A , a majority of the length of the straps  16  remains connected along the sides  24 . This creates a fairly deep opening for situations where the retractor  10  needs to hold back tissue extending a longer distance into the patient. In  FIG. 2B , the straps  16  are pulled out further and separated along most of their lengths. In this version, the retractor  10  is only being used to hold open a comparatively shallow opening.  FIG. 7  shows a version of the straps  16  where the straps  16  are connected at the base and at a discrete point  80  near the proximal end of the straps. 
         [0044]    Depending on the resilience of the tissue being retracted, the straps  16  may be merely pulled taught and attached to the loop pads  20  as seen in  FIG. 2A . Or if additional force is required, the straps  16  may be pulled and stretched, such that the resilience of the straps  16  provides additional retraction force to open and hold open the tissue surrounding the retractor  10 , as seen in  FIG. 2B . The straps  16  may be overlapped to assure that the tissue being retracted is completely covered by the straps. To accomplish this, the straps  16  may widen as they extend upward from the ring  14 . 
         [0045]    If desired, only some of the strap may be separated, as seen in  FIG. 3 . In this embodiment, a thin section near the proximal end of the device is used to connect the straps together. The user then only breaks the frangible connection between the straps for a desired number of straps. In the embodiment shown, a group of two and a group of three straps are left attached together. 
         [0046]    Using different tension on the different straps  16  may also allow the user to create a different shaped openings. Such as, stronger tension on two or four (two pair of side-by-side) opposing straps  16  could be used to create an oval or oblong opening. Other effects may be created by varying the relative widths and/or direction of pull of the straps  16 . The hook  18  and loop  20  connection also allows the user to independently position, adjust and/or reposition the straps  16  and therefore the retractor  10  during use. If desired, the hook  18  and loop  20  material may also be used as suture stays. 
         [0047]    Since the loop pads  20  may be selectively placed as needed, a single size of retractor  10  may be suitable for use for a wide range of size of patient. Further range may be provided by creating additional retractor units  10  of different sizes, including length of straps  16 , thickness of straps  16 , width of straps  16 , diameter of distal ring  14 , etc. 
         [0048]    In  FIG. 4 , the flexible ring  14  at the base of the sleeve  12  is formed of or includes an inflatable bladder  30 . A pneumatic line  32  is connected to a source of inflation medium, such as saline or other fluid or gas. The inflation medium source may be in the form of a syringe or a pump that injects the inflation medium into the inflatable bladder  30  and thereby holds the retractor  10  in place. Preferably the system has a mechanism, such as a stopcock or other standard sealing mechanism, to temporarily seal the proximal end of the pneumatic line  32  to maintain the inflation of the bladder  30 , while the retractor  10  is in use. Once the procedure is complete, the user can unseal the system and withdraw the inflation medium through the pneumatic line  32 . 
         [0049]    If desired, the ring may be adjustable. The adjustability of the ring may be created in any suitable manner.  FIG. 5  shows an embodiment of the retractor  40  that uses a ratchet type mechanism  44  to allow the user to expand the ring  42  once the ring  42  is in place. In this embodiment, the retractor  40  would be supplied to the user in a collapsed state and expanded once inserted into the chest cavity to anchor the retractor  40 . The expansion would occur by the user mechanically increasing the diameter of the opening and ring  42  by hand or with one or more instruments. A spring-loaded locking lever  46  would be biased toward the ring  42  surface and holes  48  extending into or through the ring  42 . The configuration of the locking lever  46  would allow the lever  46  to easily rise out of the holes  48  while the ring  42  is being expanded, but would be held securely in place inhibiting the ring  42  from collapsing. For the purposes of releasing the ring  42  to remove the retractor  40  after surgery, the spring  50  that biases the lever  46  toward the holes  48  would be compressed to allow the end of the lever  46  to pull out of the hole  48 , and thereby allowing the ring  42  to collapse. Alternately, a shape memory alloy could be used. The function of this alloy would be to hold the ring in its expanded state when at room temperature, and then to release the ring when it&#39;s temperature is elevated. Alternately, a component that is able to be severed by an electrosurgery probe or other surgical instrument could be used to hold the ring in its expanded state. In this case, the support component would be severed to allow the ring to collapse. 
         [0050]    Alternate versions of the adjustable ring also may be used. One version could use a mechanical stop that is actuated by hydraulic means to hold the ring in its expanded state. A piston could be actuated by hydraulic or mechanical mechanisms. Or a threaded member could be twisted to expand or contract the ring. 
         [0051]    Additionally, the distal end of the device  60  can be outfitted with a light source  62  for the purposes of illuminating the surgical site. The light  62  may take the form of an accessory that is attachable to the retractor or it may be integrally formed with the retractor  60 .  FIG. 6  shows a retractor  60  having a series of batteries  64  molded into silicone in one or more of the straps  16 . A series of LED&#39;s  66  are also molded into the silicone around the distal ring  14 . Leads  68  connect the LED&#39;s  66  and batteries  64  to a switch  70 , such as a push button contact switch or other suitable switch, which allows the user to turn the light source  62  on and off. 
         [0052]    Another embodiment of the retractor  78  has an inflatable, adjustable or malleable flange extending from the bottom of the ring, as seen in  FIG. 7 . Initially, the malleable flange  82  would extend down from the ring  14 . Once the retractor  78  has been lowered into place, the flange  82  could be bent outward to help anchor the retractor  78  in place. The flange  82  could be bent only slightly or it may be bent such that it is fully perpendicular or further. The flange  82  may be bent to conform to the shape of the chest wall, ribs or other structure. Stainless steel is a suitable material, although any biocompatible or coated malleable material maybe used. This embodiment of the retractor  78  also shows adhesive patches  84  used to connect the straps  16  directly to the support surface. The adhesive patches  84  have a disposable peel off backing  86  to protect the adhesive prior to use. 
         [0053]    The retractor may be supplied as a sterile, single use device or a reusable device formed of materials suitable for sterilization procedures. 
         [0054]    Many features have been listed with particular configurations, options, and embodiments. Any one or more of the features described may be added to or combined with any of the other embodiments or other standard devices to create alternate combinations and embodiments. 
         [0055]    Although the invention has been fully described above, in relation to various exemplary embodiments, various additions or other changes may be made to the described embodiments without departing from the scope of the present invention. Thus, the foregoing description has been provided for exemplary purposes only and should not be interpreted to limit the scope of the invention as set forth in the following claims.