Abstract:
Devices and methods are disclosed for achieving hemostasis in solid visceral wounds. Such devices and methods are especially useful in the emergency, trauma surgery or military setting. In such cases, the patient may have received trauma to the abdominal viscera. The devices utilize flexible, variable depth transfixing bolts that penetrate the viscera. These bolts are pulled tight to bring the tissue into apposition and hold said tissue in apposition while the wound heals. These bolts overcome the limitations of sutures that are currently used for the same purposes. The bolts come in a variety of lengths and diameters. Since the bolts are flexible, the curvature may be adjusted by the surgeon. The devices are flexible, bendable, and conformable in their wet or dry state. They can be used either straight or through a broad range of curvatures to suit the needs of various pathologies. The bolts include pressure plates that are capable of exerting compressive pressure over broad areas of visceral wounds without causing tearing of the friable parenchyma. The bolts may be placed and removed by open surgery or laparoscopic access.

Description:
The present application claims priority benefit under 35 USC § 119(e) from U.S. Provisional Application No. 60/354,428 filed Feb. 4, 2002, entitled “TRANSFIXING PARENCHYMAL BOLT SYSTEM” which is herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The field of this invention relates to devices and methods for trauma and general surgery, combat medicine, and emergency medical services. 
     BACKGROUND OF THE INVENTION 
     As recently as the early 1990s, surgical operations for trauma were directed at the anatomic repair of all injuries at time of the initial operation. It was observed during these exercises that many patients became hypothermic, acidotic, and coagulopathic. Patients showing these three signs often died. Death often occurred in the operating room due to exsanguination, or postoperatively, due to the complications of prolonged shock and massive transfusion to replace blood lost as a result of the trauma. 
     One of the most notable developments in the recent evolution of surgery has been the reintroduction of the concept of staged laparotomy to overcome the deficiencies of the repair all-at-once approach. This new strategy of staged laparotomy employing new tactics that have been termed damage control is now used in 10% to 20% of all trauma laparotomies. 
     Sources of hemorrhage within the abdomen that are most difficult to manage include major stellate fractures in the thick, solid, parenchymal organs, especially the liver. Such injuries may involve more than one hepatic lobe, involve massive hemorrhage, and may be caused by severe blunt or penetrating trauma. While the control of most liver hemorrhage is simple, very severe anatomic wounds are difficult to manage and have a high mortality, sometimes exceeding 80%. Standard approaches to control of these wounds involve packing with gauze or omentum, if available, and deep liver sutures. Each of these techniques has serious limitations and often fails. A major technical problem has to do with the depth to which the sutures can be placed within the liver. The limitation of liver sutures to coapt or tamponade deep parenchymal wounds is clear for several reasons. Sutures may be attached to or come pre-mounted to needles of limited size and curvature making deep placement difficult or impossible. The sutures tend to tear through the friable parenchyma (the liver is especially subject to tearing and crumbling). Another problem with sutures is that since they need to be tied off to themselves or other sutures, they form a circular configuration around certain tissues and may strangulate the tissues within that circle. This strangulation causes reduced blood flow and potentially damaging ischemia for those tissues. In addition, the suture does not distribute its force adequately to compress tissues outside of a very narrow plane described by the circle of the suture path. Another key problem with the current treatment is the time taken to achieve suture hemostasis. Massive bleeding must be stopped quickly or the patient will exsanguinate (bleed a lot) and die. Placement of sutures is a time consuming process given the tools available today, the friable nature of parenchymal tissue, and the undesirability of intra-hepatic gauze packing. 
     The size and curvature of currently marketed needles is pre-set by the manufacturer. Current needles are not long or big enough to transfix major liver lacerations. Even if the needle was large, the suture method of repair causes inadequate force distribution to create hemostasis and resist progressive wound tearing. 
     New devices, procedures and methods are needed to support the strategy of damage control in patients who have experienced massive visceral injury. Such devices and procedures are particularly important in the emergency, military, and trauma care setting. These new devices, specifically parenchymal bolts, rely on the principles of broad force distribution on the tissue, pressure tamponade, ease of placement, ease of locking in place with the pressure pads, the ability to adjust tension to optimize tissue compression, and the lack of progressive tearing of the friable wound due to the high shear caused by the suture. 
     SUMMARY OF THE INVENTION 
     The devices and methods described below provide for improved haemostatic tissue apposition, especially in trauma care. The basic device is a transfixing trans-parenchymal bolt and a pressure plate with a securing bore adapted receive and securely grip the bolt. Key features of the bolt include column strength, adjustable depth of penetration, flexibility, tissue non-reactivity, quick and simple application, and adjustment of the pressure plates. The trans-parenchymal bolt uses pressure plates that are affixed to the ends of the bolt to distribute the pressure over a wide area-of tissue and compress the tissue. The key features of the pressure plates include one-way ratcheting with quick release or a friction lock, ability to quickly and cleanly remove the pressure plate, and the ability to adjust the pressure plate to ensure optimum tissue apposition and compression. The trans-parenchymal bolt and pressure plate system generates pressure tamponade to provide for wound hemostasis. The trans-parenchymal bolt may be placed through an open surgical access site or through a laparoscopic access and manipulation system. 
     Once the bolt has been placed, it remains in place either temporarily or permanently. Temporary placement necessitates removal of the bolt. The bolt may be made from materials that permit long-term implantation or it may be fabricated from resorbable materials that obviate the need to remove the bolt in a subsequent surgical procedure. Both the bolt and the pressure plates are fabricated from materials with smooth outer surfaces that do not encourage tissue or clot ingrowth. The bolts and pressure plates are radiopaque and can be visualized on fluoroscopy or X-ray. Thus, the bolts and pressure plates may be removed with minimal re-bleeding. 
     The current medical practice of utilizing sutures is not an optimized solution to open visceral wound repair. Sutures were not designed for use in parenchymal tissue. The present invention distinguishes over the current medical practice because the present invention is tailored to the needs of open visceral wound repair. The parenchymal bolts are stiff enough to serve as their own needles, trocars, or stylets. They may be flexed or permanently deformed to achieve the desired tissue compression. They are suited for either open surgical implantation and removal, or they are suited for laparoscopic placement and removal using specialized access, grasping and delivery instruments. When the trans-parenchymal bolts of the present invention are removed from the patient, re-bleeding does not occur because there is minimal penetration of the wound tissues or clot into the interstices of the bolt and pressure plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates a longitudinal cross-sectional view of the parenchymal bolt; 
         FIG. 1B  illustrates a lateral cross-sectional view of the parenchymal bolt near one of the ends; 
         FIG. 1C  illustrates a lateral cross-sectional view of the parenchymal bolt near the center; 
         FIG. 2A  illustrates a side view, of the pressure plate and locking nut in cross-section; 
         FIG. 2B  illustrates an end view of the pressure plate and locking nut also showing the lock release; 
         FIG. 3  illustrates a longitudinal cross-sectional view of the parenchymal bolt, two pressure plates and two locking nuts; 
         FIG. 4  illustrates a longitudinal cross-sectional view of the parenchymal bolt, two pressure plates and two locking nuts wherein the parenchymal bolt has been malleably deformed into a right angle bend; 
         FIG. 5A  illustrates a typical wound to the liver; 
         FIG. 5B  illustrates preparations for open access liver wound hemostasis using three parenchymal bolts, six pressure plates and six ratcheting locks; 
         FIG. 5C  illustrates the wound to the liver following temporary repair with three parenchymal bolts, six pressure plates, and six ratcheting locks; 
         FIG. 6A  illustrates a wound to the liver being repaired through laparoscopic access by application of a parenchymal bolt; 
         FIG. 6B  illustrates application and tightening of a pressure plate and ratcheting lock via laparoscopic instrumentation; 
         FIG. 6C  illustrates the wound to the liver following laparoscopic placement of three parenchymal bolts, six pressure plates, and six ratcheting locks; 
         FIG. 7A  illustrates a side cross-sectional view of a parenchymal tissue injury with a parenchymal bolt, two pressure plates, and two ratcheting locks prior to tightening; 
         FIG. 7B  illustrates a side cross-sectional view of the parenchymal tissue injury during tightening of the ratcheting locks; 
         FIG. 8  illustrates a longitudinal cross-sectional view of a parenchymal bolt comprising pressure plates and friction locks. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1A  illustrates a longitudinal cross-sectional view of a parenchymal bolt  10  of the present invention. The parenchymal bolt  10  comprises an inner core  12 , an outer coating  14 , a central region  16 , two ends  18 , and a plurality of serrations  20  on one or both ends  18 . The parenchymal bolt  10  further comprises an optional pointed tip or trocar  22 . The inner core  12  of the parenchymal bolt  10  is coaxially affixed to interior of the outer coating  14 . The central connecting region  16  is disposed between the ends  18 . One or both of the ends  18  of the parenchymal bolt  10  comprise a plurality of serrations  20  disposed longitudinally, along at least one side of one or more ends  18 . The optional pointed tip or trocar  22  is removably affixed coaxially to one or more of the ends  18 . The inner core  12  of the parenchymal bolt  10  provides column strength and the ability to be malleable or elastomeric, depending on the patient requirements. The preferred configuration of the inner core  12  is that it is malleable and located in the central region  16  only. The ends  18  are, preferably, elastomeric and do not have the malleable inner core  12  disposed therethrough. An advantage of having only polymeric material comprise the ends  18  is that the ends can be easily cut off or trimmed to size once the parenchymal bolt  10  is fully installed or placed in the patient (though the inner core may extend completely from end-to-end should the additional strength of this construction be needed, and trimming can be accomplished readily during an operation). Column strength is important so that tension may be transmitted through the parenchymal bolt  10 , even when the parenchymal bolt  10  has been bent into an arc. Column strength also permits the parenchymal bolt  10  to be forced through tissue much the same as a suture needle would be forced through tissue. Malleability is important so that the parenchymal bolt  10  can be bent into the correct curvature needed for optimum coaptation of the tissue being repaired. 
     The inner core  12  is fabricated from materials such as stainless steel, cobalt-nickel alloys, nitinol, tantalum, titanium, polylactic acid, polyglycolic acid, platinum, and the like. The inner core  12  is preferably radiopaque and visible under fluoroscopy or X-Ray. It is important that the parenchymal bolt  10  be radiopaque so that the position of bolts can be confirmed after implantation, though radiolucent materials may also be used when appropriate. The outer coating  14  may be fabricated from polymers such as, but not limited to, polypropylene, polyethylene, polyester, polyurethane, polylactic acid, polyglycolic acid, polyimide or copolymers of these materials. In a preferred embodiment, the bolt  10  comprises radiopaque markers. The markers are fabricated from tantalum, gold, platinum, stainless steel, titanium, nitinol, cobalt nickel alloys and the like. The markers show the extents of the outer coating  14 . The addition of barium, barium compounds, or the like in concentrations of up to about 40% in the polymer provides for radiopacity. The outer coating  14  may also be made from the same materials as are used to fabricate the inner core  12 . The outer coating  14  may be the same physical structure as the inner core  12  (that is, formed integrally with the core). Preferably, the outer coating  14  is smooth and does not allow tissue ingrowth. 
     One or both of the ends  18  comprise an optional sharpened or tapered tip  22  to pierce tissue with minimal resistance. The optional pointed tip or trocar  22  facilitates passage of the parenchymal bolt  10  through tissue. The pointed tip or trocar  22  may be removed to minimize further tissue damage while the parenchymal bolt  10  is in place, and for this purpose, a releasable attachment means is provided on the proximal end of the trocar  22 . In a preferred embodiment, the pointed tip or trocar  22  is removably attached to the ends  18  by a male threaded stub  21  that is mated into a female threaded adapter on the end  18 . A bayonet mount or friction fit is another suitable method of releasably attaching the pointed tip or trocar  22  to the end  18 . In another embodiment, the pointed tip or trocar  22  may also be longitudinally disposed through the entire core of the parenchymal bolt  10  and is removed by simply withdrawing the trocar  22  from the parenchymal bolt  10 . The removable sharp tip  22 , in a further embodiment, is retractable within the end  18  of the parenchymal bolt  10 . 
     One or more of the ends  18  comprise the plurality of serrations  20  that permit locking with devices that are attached to the parenchymal bolt  10  in a later process. The serrations  20  are, preferably, triangular in shape and project outward from the longitudinal axis of ends  18 . One side of the triangular projection is perpendicular to the longitudinal axis of the end  18 . The perpendicular side of the triangle may also be undercut. Another side is tapered away from the end  18  and forms a ramp moving inward from the end  18  toward the center  16  of the parenchymal bolt  10 . 
       FIG. 1B  illustrates a cross-section of the parenchymal bolt  10  taken near one of the ends  18 . The cross-sectional view of the end  18  further comprises one or more optional tracking grooves  24  and one or more optional longitudinal ratchet slots  25 . The tracking groove  24  is a slot and is disposed longitudinally along the length of ends  18 . The longitudinal ratchet slot  25  is disposed longitudinally along the length of ends  18 . 
     Referring again to  FIGS. 1A and 1B , the serrations or ratchet teeth  20  are disposed within the ratchet slot  25 . The height of the serrations is preferably smaller than the dept of the ratchet slot, so that the ratchet slot  25  holds and hides the serrations from the tissue as the parenchymal bolt  10  is advanced through the tissue to minimize trauma. The tracking groove  24  is used to provide alignment for parts that will be mated to the parenchymal bolt  10 . By having two sets of tracking grooves  24 , bilateral symmetry is achieved and parts can be mated in two orientations, rather than just one, thus facilitating the mating process. One ratchet slot  25  is required for each set of serrations and two ratchet slots  25  permit orientation of mating parts in more than one orientation. When more than one ratchet slot  25  and tracking groove  24  are used on each end, the second slot  25  or groove  24  is disposed 180 degrees around the end  18  circumference from the first slot  25  or groove  24 . 
       FIG. 1C  illustrates a cross-section of the central region  16  of the parenchymal bolt  10 . The central region  16  comprises the core  12  and the outer coating  14 . The outer coating  14  is disposed coaxially around the core  12 . The optional tracking grooves  25  are not shown in this cross-section. 
       FIG. 2A  illustrates a cross-sectional view of a pressure plate  26  and a ratcheting lock  28 . The pressure plate  26  further comprises one or more pass through holes  30 . The ratcheting lock  28  further comprises a plurality of locking tabs or pawls  32 , a tracking protrusion or rail  34 , and a central hole  36 . The tracking rail  34  is sized and dimensioned to fit into the tracking groove  24  of the bolt end  18 . The ratcheting lock  28  is disposed coaxially with the pass through hole  30  on the pressure plate  26 . The ratcheting lock  28  may be affixed to the pressure plate  26 , formed integral integrally with the pressure plate  26 , or provided as a separate piece outside the pass through hole  30  of the pressure plate  26 . The locking tabs  32  are flexibly affixed to the ratcheting lock  28  and project inward with a vertical edge toward the pressure plate  26  and a ramped edge sloping away from the pressure plate  26 . The tracking protrusion  34  is one or more small projections into the central hole  36  of the ratcheting lock  28 . The pressure plate  26  may have a single pass through hole  30  or it may have the plurality of pass through holes. With the plurality of pass through holes  30 , one pressure plate  26  can be used with multiple parenchymal bolts  10 . 
     Referring to  FIGS. 1A ,  1 B, and  2 A, the end  18  is configured to mate with the ratcheting lock  28  and the pressure plate  26 . When the ratcheting lock  28  is advanced over one of the ends  18 , through the central hole  36 , the flexible locking tab or pawl  32  on the ratcheting lock  28  is bent aside by the ramp formed on the outside of serrations or ratchet teeth  20  and allows advancement of the ratcheting lock  28  to continue. Pulling backward on the ratcheting lock  28  or pressure plate  26  causes the vertical edge of the locking tab  32  to dig into the perpendicular sides described by the inner edges of the serrations  20  on the ends  18  so the ratcheting lock  28  will not slip backwards. The tracking protrusion  34  slidably mates with the alignment groove  24  on the end  18  to prevent the locking tabs  32  from becoming misaligned with the serrations  20  and inadvertently disengaging. 
       FIG. 2B  illustrates an end view of the pressure plate  26  and the ratcheting lock  28 . As seen in this view, the ratcheting lock  28  further comprises a lock release  38 . The locking tabs  32  project inward toward the center of the central hole  36  in the ratcheting lock  28 . The lock release  38  is activated by manual pressure or by a laparoscopic instrument to bend back and release the locking tab  32  from the serrations  20  so that the ratcheting lock  28  and pressure plate  26  may be removed from the end  18 . The lock release  38  allows for quick release of the ratcheting lock  28  and pressure plate  26 . In another embodiment, the lock release  38  retracts the tracking protrusions  34  so that the ratcheting lock  28  can be rotated to disengage the locking tabs  32  from the serrations  20  and enable removal of the ratcheting lock  28  and the pressure plate  26  from the parenchymal bolt  10 . 
     The pressure plate  26 , the ratcheting lock  28  and the lock release  38  are fabricated from the same materials as are used in fabrication of the parenchymal bolt  10 . All parts are designed with smooth outer surfaces to minimize the opportunity for tissue or thrombus ingrowth. The pressure plate  26  is stiff enough to distribute pressure to gently hold the tissue together while it heals. In a preferred embodiment, the pressure plate  26  and the ratcheting lock  28  are radiopaque. Materials such as barium, barium compounds, or radiopaque metals or the like, comprise at least part of the pressure plate  26  or lock  28 . The pressure plate  26  and the lock  28  comprise, at least in part, the materials including those used in fabrication of the core  12  and the outer coating  14 . 
     The length of the parenchymal bolt  10  ranges from 0.5 cm to 500 cm depending on the tissue being compressed. More preferably, the length of the parenchymal bolt  10  ranges from 2 cm to 50 cm (about 1 to 20 inches). The diameter of the parenchymal bolt  10  varies and is in proportion to the length of the bolt  10 . Diameter ranges of between 0.5 mm and 10 mm are appropriate for the parenchymal bolt  10 . The pressure plate  26  is sized to the organ being compressed. The pressure plate  26  has roughly rectangular dimensions ranging from a minimum of 0.5 cm to a maximum of 100 cm. The preferred range of sizes for the pressure plate  26  is 1 cm to 20 cm (about 0.5 inches to 8 inches). The pressure plate  26  thickness ranges from 0.5 mm to 30 mm. 
       FIG. 3  illustrates a longitudinal cross-sectional view of the parenchymal bolt  10  with two pressure plates  26  and two ratcheting locks  28 . The pointed tip or trocar  22  has been removed in this view. The pressure plates  26  and ratcheting locks  28  have been pushed over the ends  18  of the parenchymal bolt so that the locking tabs  32  have engaged the serrations  20 . 
       FIG. 4  illustrates a longitudinal cross-sectional view of the parenchymal bolt  10  with two pressure plates  26  and two ratcheting locks  28 . The parenchymal bolt  10  has been malleably deformed in its central region  16  and maintains that shape because the core  12  has sufficient strength to overcome the elastic forces generated by the outer covering  14 . 
       FIGS. 5A through 5C  illustrate the intended use of the parenchymal bolt.  FIG. 5A  illustrates a wound  42  in a liver tissue  40 . The liver is a prime example of parenchymal tissue that often receives damage during abdominal trauma and during the surgery intended to repair that trauma. Note that the parenchymal tissue of the liver  40  is friable and unable to sustain high stresses without fracturing or tearing. 
       FIG. 5B  illustrates open surgical preparation for repair of the liver wound  42  according to the methods of the present invention. The surgeon presses opposing sides of the rupture together, “approximating” the tissue on either side of the wound. Several parenchymal bolts  10 , six pressure plates  26  and six ratcheting locks  28  are provided for the procedure while the liver  40  apposition is accomplished with manual pressure. 
       FIG. 5C  illustrates completion of the repair of the wound  42  to the liver  40  using the parenchymal bolts  10 , pressure plates  26  and ratcheting locks  28 . After the bolts are bent into shape desired the by surgeon (any angle desired by the surgeon can be achieved manually), the surgeon shoves the bolts through the liver. The surgeon forces the bolts first into the liver on one side of the wound, and then upwardly and out of the liver on the other side of the wound, so that both ends of the bolt stick out of the liver with the ratchets exposed. The surgeon then slips the pressure plate and ratcheting locks onto each end. The ratcheting locks  28  are pushed onto the bolt, and tightened sufficiently to hold the pressure plates  26  firmly against the tissue causing complete wound  42  closure and hemostasis. 
       FIGS. 6A through 6C  illustrate a laparoscopic approach to approximating and securing the tissue of a ruptured organ using the bolts, pressure plates and ratchet mechanisms.  FIG. 6A  illustrates the wound  42  to the liver  40  with the parenchymal bolt  10  being applied by a laparoscopic instrument  44 . In this embodiment, the laparoscopic instrument  44  is a grasper or set of jaws, placed through an axially elongate hollow structure, that may be manipulated by the surgeon from the outside of the patient. After the bolts are bent into shape desired the by surgeon (any angle desired by the surgeon can be achieved manually), the surgeon shoves the bolts through the liver. The bolts may be bent to shape before or after placement in to the laparoscopic workspace. Using the laparoscopic graspers, the surgeon forces the bolts first into the liver on one side of the wound, and then upwardly and out of the liver on the other side of the wound, so that both ends of the bolt stick out of the liver with the ratchets exposed. 
       FIG. 6B  illustrates the wound  42  to the liver  40  following placement of the first parenchymal bolt  10 , two pressure plates  26  and two ratcheting locks  28  using the first laparoscopic instrument  44  and a second laparoscopic instrument  46 . Again, the laparoscopic instruments  44  and  46  are placed through an axially elongate hollow structure that provides access to the internal organs of the patient. The laparoscopic grasping device  46  is placed around the ratcheting lock  28  and is used to advance the ratcheting lock  28  and pressure plate  26  inward against the liver tissue  40 . The laparoscopic grasping device  44  applies tension to the parenchymal bolt  10  so that the pressure plate  26  and the ratcheting lock  28  move relative to the parenchymal bolt  10 . The laparoscopic grasping instruments  44  and  46 , which may be similar to very long nosed pliers, may be replaced by a single instrument that performs both functions of stabilizing the parenchymal bolt  10  and advancing the ratcheting lock  28 . This type of procedure is generally performed under direct vision through laparoscope placed within the surgical field, but may also be visualized with a video display fed by a camera attached to the endoscope. 
       FIG. 6C  illustrates the wound  42  to the liver  40  following laparoscopic repair with three parenchymal bolts  10 , six pressure plates  26  and six ratcheting locks  28 . Thus,  FIGS. 5A through 5C  and  6 A through  6 C illustrate the manufacture of a tissue approximating device by bending a malleable bolt, forcing the bolts through the body tissue, and fitting a pressure distributing plate onto the ends of the bolt and forcing the pressure plates into contact with the body organ, and securing the pressure plates in fixed longitudinal relationship with the bolt by fixing the ratcheting lock onto the ends of the bolts, and forcing the pressure plate and ratcheting locks into contact with the body tissue. The ratchet structure of the bolt and the ratchet lock comprise a means for longitudinally fixing the pressure plate along the length of the bolt. Other means for fixing the pressure plate, including threaded nuts combined with outside threads on the bolt ends, may be also be used to accomplish this function. For body tissue such as internal organs, which present a single surface in the operating field, the bolts are bent and forced through the organ such that both ends protrude from the presenting surface of the organ. 
       FIG. 7A  illustrates a side cross-sectional view of the wound  42  to parenchymal tissue  40 , in this case the liver  40 , following initial repair with the parenchymal bolt  10  of the present invention. The repair of the wound  42  comprises placement of the parenchymal bolt  10  followed by placement of two pressure plates  26  and two ratcheting locks  28 . 
     Referring to  FIG. 7A ,  FIG. 1A  and  FIG. 2A , the pointed tip or trocar  22  has been removed or retracted following full tissue  40  penetration by the parenchymal bolt  10 . Two pressure plates  26  have been applied to the ends  18  of the parenchymal bolt  10  to transfix the tissue  40 . Two ratcheting locks  28  are in the process of being tightened over the pressure plates  26  and the wound  42  is still open. 
       FIG. 7B  illustrates the wound  42  in the parenchymal tissue  40  at a point where the ratcheting locks are nearly tightened against the tissue  40 . The wound  42  has achieved nearly complete closure. Additional inward tightening of the ratcheting locks  28  will compress the pressure plates  26  and achieve full wound  42  closure and hemostasis. The surgeon may bend the bolts after placement, as seen in  FIG. 7B , to help pull the edges of the wound together. The parenchymal bolt  10  flexes to accommodate the change in wound geometry as the ratcheting locks  28  are tightened. 
       FIG. 8  illustrates another embodiment of the parenchymal bolt  10 , shown in longitudinal cross-section. The parenchymal bolt  10  further comprises an axially elongate shaft  14 , a malleable central component  12 , a sharpened tip  22 , one or more pressure plates  26 , and one or more friction locks  50 . The friction lock  50  further comprises a friction generator  52  and a housing  54 , which further comprises a grasping bump  56 . The friction lock  50  may be separate or integral to the pressure plate  26 . The friction lock  50  is fabricated from biocompatible polymeric materials such as, but not limited to polyethylene, polypropylene, ABS, PVC, stainless steel, PTFE, titanium, PLA, PGA, and the like. In the preferred embodiment, the friction lock  50  comprises a friction generator  52 , which is a disc with a hole in the center. The hole is smaller in diameter than the outside diameter of the axially elongate shaft  14  of the parenchymal bolt  10 . The friction generator  52  comprises elastomeric materials that exert an inward pressure and generate friction against the outside diameter of the axially elongate shaft  14 . Such elastomeric materials include, but are not limited to, polyurethane, silicone elastomer, latex rubber, and the like. The friction exerted by the friction lock  50  against the axially elongate shaft  14  is sufficient to resist the force of the tissue resilience once engaged in contact but insufficient to prevent manual movement generated by the surgeon either applying or removing the friction lock  50  from the axially elongate shaft  14 . The housing  54  further comprises a grasping surface  56 , which is a bump or other feature that allows for easy grasping by the surgeon in a wet or slick environment so that the friction lock  50  may be removed retrograde from the shaft  14  of the parenchymal bolt  10 . Other embodiments of the friction lock  50  include those that comprise a jam cleat, an over-center cam, a spring-loaded friction member, and the like. The friction lock  50  preferably does not comprise a release mechanism but in certain configurations, a button or latch to release the friction is required. 
     Application of the parenchymal bolt system provides improved speed of solid organ trauma repair and minimizes the chance of tissue tearing or fracture, relative to the use of sutures for said repair. The parenchymal bolt system provides pressure tamponade to the injured tissue to provide for hemostasis and maximize the recovery process while minimizing complications common to suture-based approaches. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. For example, the ratcheting locks could be replaced by simple threaded nuts that engage threads on the parenchymal bolt. The bolt may comprise telescoping tubes that slide and lock relative to each other, thus obviating the need to cut off excess material projecting away from the pressure plate. Additionally, though described in the context of internal organs, the device and methods may be used to approximate wounds in muscle tissue or fibrous tissue. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.