Patent Publication Number: US-2005125015-A1

Title: Tissue-handling apparatus, system and method

Description:
BACKGROUND  
      The use of sutures is the mainstay of most forms of modern-day surgery. For example, until very recently, virtually all ophthalmic surgery was only possible with specialized sutures and needles. Strabismus correction, corneal transplantation, vitreoretinal surgery, trauma repair, oculoplastic procedures, glaucoma surgery, and extracapsular cataract removal all require precise suture placement through various fine structures of the eye and adnexa. While microscopes, loupe magnification and specialized illumination techniques have made it easier to perform ophthalmic surgery, suture placement is technically difficult, time-consuming and may be associated with serious complications.  
      In particular, strabismus surgery requires that a suture be inserted and advanced within the sclera at a depth of approximately half the scleral thickness. This is usually performed with the aid of loupe magnification. Perforation of the sclera during reattachment of an extraocular muscle may be associated with the vision-threatening complications of retinal detachment and endophthalmitis. 1,2  It has also recently been suggested that contaminated intrascleral sutures may produce endophthalmitis even in the absence of scleral perforation. 3,4  Suture use in corneal transplantation may be associated with postoperative astigmatism and wound leakage. 5  Traumatic stellate corneal lacerations can be difficult to close using sutures due to their complex, irregular geometry, while posterior scleral sutures required in the repair of a ruptured globe may be arduous to insert without putting excessive pressure on the eye.  
      Inherent complications and drawbacks of suture use are numerous. Suture placement can be time-consuming. Sutures must be placed very precisely in order to properly align the tissue. Often the tissue must be manually realigned before each pass of the suture&#39;s needle. Imprecise placement of a suture may necessitate its removal and replacement; as a result, delicate ocular tissues may be damaged. Sutures frequently must be removed postoperatively. Not only is this time-consuming, but children often require either restraint, sedation, or additional exposure to general anesthetics. Sutures can also produce allergic reactions and act as a nidus for infection. Finally, sutures pose the risk of needle-stick injury and transmissible infections for operating room personnel.  
      Currently, the only sutureless ophthalmic procedure is small-incision phacoemulsification of cataractous lenses. Attempts at utilizing bioadhesives in ophthalmic surgery have been limited. At present, the only bioadhesives used in clinical ophthalmic procedures are cyanoacrylates for corneal perforations. 6,7  Fibrin glue has been used for experimental strabismus surgery in rabbits, but its tensile strength has been disappointing. 8,9  2-octyl-cyanoacrylate glue has also been used for rabbit strabismus surgery, 10  as well as attaching rabbit extraocular muscles to porous anophthalmic implants, 11  and has demonstrated greater adhesive strength than fibrin glue. However, liquid adhesives may be difficult to precisely position on the sclera and the rapid hardening time after placement requires quick and accurate placement of the muscle. Cyanoacrylate glue has also proven to be of limited efficacy in the repair of leaking filtering blebs. 12    
      One major complication limiting acceptance of such adhesives is associated with the difficulty in delivering the surgical adhesive to the repair site. The fluid adhesives tend to run away from the application site, resulting in insufficient quantities of the adhesive being present to provide a strong bond, or potentially worse, tissues adhering together at locations other than that intended.  
      Improvements to currently available biologic and synthetic adhesives are addressed in a co-pending U.S. Patent application: Non-Light Activated Biological Adhesive Device, System, and Methods of Use Thereof, Ser. No. 10/610,068, filed June 2003 (co-inventors McNally-Heintzelman K M, Heintzelman D L, Bloom J N and Duffy M T). The present application describes two new surgical instruments for handling tissue, particularly muscle tissue, during surgery. These instruments are intended for use in ophthalmic surgeries as well as other types of internal or external surgery. At least one embodiment is designed to facilitate the use of an adhesive composite such as is described in the above-mentioned U.S. patent application, and other surgical adhesives and adhesive-enhanced repair techniques.  
      While the present invention has been described with respect to particular applications in ophthalmic procedures, it is understood that it is capable of broader application, for example, in other types of surgical procedures.  
     SUMMARY  
      One aspect of the present invention relates to an apparatus, system and method for facilitating the handling of tissue, particularly muscle tissue, during surgical procedures. Strabismus surgery, for example, commonly entails recessions of eye muscles if weakening of muscles is required, and resections of eye muscles when strengthening of eye muscles is required. Recession of an eye muscle requires disinsertion of one of the six muscles attached to the eye, and reattachment of the muscle further back on the eye, thereby causing weakening. Resection of an eye muscle requires disinsertion of the muscle from the eye, excising a portion of the distal end of the muscle, and subsequent reattachment to the eye, thereby resulting in a stronger muscle.  
      Prior to disinsertion, a suture is typically pre-placed in the muscle, by threading it through the tissue, in order to secure the muscle after it is disinserted from the sclera and prevent it from retracting back into the orbit. Thus, even if a suitable adhesive is available, the surgery is not truly sutureless. Suture location within the muscle may vary between surgeons, or even for the same surgeon, producing variable surgical outcomes. The needle of the suture may also damage the muscle as it is passed through it and poses a risk of scleral perforation during this pre-placement within the muscle tissue. In addition, improperly locating the suture within the muscle may cause the suture to pull through the muscle and allow the muscle to retract back into the orbit, producing the serious complication of a “lost” muscle. The present invention provides a sutureless method for precisely holding the muscle during the disinsertion and reinsertion process.  
      Another aspect of the present invention relates to a clamp that is configured to keep a muscle spread to its full tendon width, allowing the tendon edge to be precisely placed against the adhesive material. In contrast, with the use of a suture to hold the muscle, it is difficult to maintain a perfectly spread muscle, with narrowing of the muscle width typically occurring at the time it is reattached to the sclera. This bunching-up of tissue can lead to incorrect placement of the muscle on the surgical adhesive.  
      Yet another aspect of the present invention relates to the atraumatic use of non-slip teeth or tooth-like structures to hold the muscle at strategic points, thereby providing a non-crushing grip of the tendon or muscle.  
      Yet another aspect of the present invention relates to a method of application that provides for an accelerated surgical procedure. According to one embodiment of the method, a clamp is placed on the muscle immediately prior to its disinsertion, and remains in place during the entire procedure. The clamp is configured to facilitate release and reattachment of the muscle without re-gripping or damaging the tissue.  
      Another aspect of the invention involves an alternative design of a clamp for use in connection with an apparatus for handling muscle tissue. The alternative clamp is configured to allow more user control over the disinserted muscle. In one embodiment, the clamp includes a “dual-action” feature. In another embodiment, the alternative clamp is configured to reduce the amount of muscle manipulation needed to secure the muscle. In a further embodiment, the clamp has an adjustable width. In still another embodiment, the clamp is configured to reduce the amount of necessary contact with the muscle.  
      Another alternative form of the apparatus of the present invention is configured to facilitate application of an adhesive composite to tissue to achieve a desired placement of the composite on the tissue. For example, in strabismus surgery, it may be desired to position the composite as a bridge to ophthalmic tissues such as the sclera. This configuration allows for one-step attachment of the muscle to the sclera (versus the known two-step process of first placing the adhesive on the sclera and then placing the muscle on top of the adhesive). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side view of a first embodiment of an apparatus for handling tissue.  
       FIG. 2  is a top view of a second alternative embodiment of an apparatus for handling tissue. 
    
    
     DETAILED DESCRIPTION  
       FIG. 1  shows a tissue handling apparatus  100  designed to facilitate the handling of muscle tissue in particular. The illustrated embodiment is configured to hold muscle in an extended (unretracted) position. Preferably, in ophthalmic surgeries, the muscle is spread to its full tendon width, and the illustrated embodiment of tissue handling apparatus  100  is designed to be capable of holding muscle in such a fully-extended position.  
      Tissue handling apparatus  100  includes a handle such as an elongated member  102 . The handle  102  has a substantially L-shaped end portion having a clamp end  104  and a first clamp portion  106 . As shown, elongated member  102 , clamp end  104 , and first clamp portion  106  are of substantially one-piece (e.g., molded) construction. It is understood, however, that clamp end  104  may be coupled to elongated member  102  and first clamp portion  106  by any suitable means known in the art (e.g., solder, adhesive, fasteners, etc.). First clamp portion  106  and second clamp portion  110  form clamp  120 .  
      Also coupled to the handle  102  is an actuator  118  for operating the clamp  120 . As illustrated, coupled to the elongated member  102  are slide mechanism  118  and sliding member  108 . Slide mechanism  118  operates to move sliding member  108  back and forth in the directions of arrow  122 . Sliding member  108  slides back and forth within a hollowed portion, slot or track (not shown) of elongated member  102 .  
      Slide mechanism  118  includes a slide  116  and a slide actuator  114 . When not actuated, slide mechanism  118 , and consequently sliding member  108 , are in a locked position. When pressure is applied to slide actuator  114 , slide mechanism unlocks and slide  116  becomes movable in the directions of arrows  124  and  126 .  
      For example, pressure may be applied to slide actuator  114  via a thumb or index finger of a medical professional. Pressing downwardly on slide actuator  114  unlocks slide mechanism  118 . Releasing pressure from slide actuator  114  causes slide mechanism  118  to be disabled or locked.  
      Slide  116  is mechanically coupled to sliding member  108  by suitable means known in the art, such that slide  116  slides along the slot or track discussed above. Movement of slide  116  in the direction of arrow  124  causes sliding member  108  to move in the direction away from elongated member  102 , widening the space between clamp portions  106  and  110 . Movement of slide  116  in the direction of arrow  126  causes sliding member  108  to move toward elongated member  102 , narrowing the gap between clamp portions  106  and  110 .  
      It will be appreciated by those skilled in the art that other suitable mechanical or electrical means for adjusting clamp  120  may be used equally as well as slide mechanism  118 .  
      Each of clamp portions  106 ,  110  includes at least one tissue grip portion such as protrusion  112  extending outwardly from its inner edge toward the opposite blade. Protrusions  112  are configured to grip the tissue without slipping and without crushing or otherwise damaging the tissue. In the illustrated embodiment, protrusions  112  are substantially tooth-like in shape. It is understood that protrusions  112  may taper to a point and thus be substantially cone-like or pyramid-like in shape. Alternatively, protrusions  112  may be untapered and have a flat, rectangular or cube-like shape.  
      During a surgical procedure, the above-described apparatus  100  is suitable for use as follows. After the targeted tissue is isolated, clamp  120  is placed on the tissue. The position of second clamp portion  110  is adjusted using slide mechanism  118  to ensure that protrusions  112  engage the tissue at the desired points. Once clamp  120  is in place, slide mechanism  118  is disabled or locked as described above so that clamp  120  remains in the desired position during the duration of the surgery.  
      In the case of muscle tissue, the positioning of clamp  120  keeps the muscle spread to its full tendon width. Consequently, the surgical procedure, including release and reattachment of the muscle, can be performed, and an adhesive can be applied to the affected area, while clamp  120  remains in place as originally positioned.  
      In  FIG. 2 , an alternative “dual-action” embodiment  200  of a tissue-handling apparatus in accordance with the present invention is shown. Tissue-handling apparatus  200  includes first and second handle portions or clamp arms  216 ,  218  and first and second clamps  244 , 246  operable via first and second slide mechanisms  220 ,  222 . As illustrated, the clamp arms  216 ,  218  are substantially parallel to one another.  
      Each clamp arm  216 ,  218  includes a respective curved portion  208 ,  210 . Curved portions  208 ,  210  are coupled together via coupler or end portion  206 .  
      A width adjuster  262  is also provided. Width adjuster  262  includes first and second cross members  256 ,  258 , which are coupled to each other and post  204  via coupler  260 . Each cross member  256 ,  258  is coupled to the respective clamp arm  216 ,  218  via a fastener  212 ,  214 . Fasteners  212 ,  214  may be screws, nuts, or other suitable fasteners known in the art. Alternatively, a solder or adhesive may be used to couple first and second cross members  256 ,  258  to clamp arms  216 ,  218 . Cap  202  is provided on the end of post  204  opposite coupler  260 .  
      As shown, first and second cross members  256 ,  258  and coupler  260  are of substantially one-piece construction, coupler  260  is a hollow cylinder, and one end of post  204  fits within the hollow portion of coupler  260 . However, it is understood that any other suitable electrical or mechanical means for adjusting the width  264  between clamp arms  216 ,  218  may be used equally as well.  
      Each clamp  244 ,  246  includes a first clamp portion  240 ,  242  coupled respectively to a clamp end  232 ,  234 , second clamp portions  248 ,  250 , and protrusions  252 ,  254 . Second clamp portions  248 ,  250  are coupled to or part of sliding members  236 ,  238 .  
      Sliding members  236 ,  238  are operable to adjust the positioning of clamps  244 ,  246  via sliding mechanisms  220 ,  222  as discussed above. Sliding mechanisms  220 ,  222  include slide actuators  224 ,  226  and slides  228 ,  230 , which operate as described above.  
      During a surgical procedure, tissue-handling apparatus  200  is suitable for use as follows. Either or both of clamps  244 ,  246  are used as described above to secure the tissue in the desired position. Forceps or other suitable means are used to place a biological scaffolding or adhesive composite on the tissue in a desired location, for example, to join two pieces of tissue (i.e., edges of a wound) or to close a wound.  
      For example, in ophthalmic surgery, one or both of clamps  244 ,  246  are used to position and hold the muscle in the desired location with respect to the sclera. The choice to use one or two clamps may depend on surgeon preference and/or style of muscle-adhesive-sclera apposition. A biological scaffolding or adhesive composite is then placed directly over the area where the muscle and sclera are to be rejoined (i.e., so the composite acts as a “bridge”), thereby allowing the respective edges of the muscle and sclera to be properly aligned and facilitating healing.  
      The various embodiments of tissue handling apparatus  100 ,  200  are made of surgical steel or other suitable material known in the art. It is understood that certain portions of tissue handling apparatus  100 ,  200  may be coated or enclosed in a synthetic material such as a foam, rubber or other suitable high-friction material to provide for easier maintenance and handling by the medical professional.  
      Although the present invention has been described in detail with reference to certain exemplary embodiments, it is understood that variations and modifications exist and are within the scope and spirit of the present invention.  
     REFERENCES  
      All of the following references, whether or not specifically cited elsewhere in this disclosure, are incorporated herein by this reference. 
      1. Noel L P, Bloom J N, Clarke W N, Bawazer A. Retinal perforation in strabismus surgery.  J Pediatr Ophthalmol Strabismus . 1997;34:115-117.     2. Awad A H, Mullaney P B, Al-Hazmi A, Al-Turkmani S, Wheeler D, Al-Assaf M, et al. Recognized globe perforation during strabismus surgery: incidence, risk factors, and sequelae.  JAAPOS . 2000;4:150-153.     3. Recchia F M, Baumal C R, Sivalingam A, Keiner R, Duker J S, Vrabec T R. Endophthalmitis after pediatric strabismus surgery.  Ophthalmol . 2000;118:939-944.     4. Rosenbaum AL. Endophthalmitis after strabismus surgery.  Arch Ophthalmol . 2000;118:982-983.     5. Whitson W E, Weisenthal R W, Krachmer J H. Penetrating keratoplasty and keratoprosthesis; Tasman W, Jaeger E A (ed.);  Duane&#39;s Clinical Ophthalmology , Philadelphia, Lippincott Williams and Wilkins; 2001, vol. 6, chap. 26, pp 1-28.     6. Vote B J, Elder M J. Cyanoacrylate glue for corneal perforations: a description of a surgical technique and a review of the literature.  Clin Experiment Ophthalmol . 2000;28:437-442.     7. Taravella M J, Chang CD. 2-Octyl cyanoacrylate medical adhesive in treatment of a corneal perforation.  Cornea . 2001;20:220-221.     8. Spierer A, Barequet I, Rosner M, Solomon A S, Martinowitz U. Reattachment of extraocular muscles using fibrin glue in a rabbit model.  Invest Ophthalmol Vis Sci . 1997;38:543-546.     9. Erbil H, Sinav S, Sullu Y, Kandemir B. An experimental study on the use of fibrin sealants in strabismus surgery.  Turk J. Pediatr .1991;33:111-116.     10. Ricci B, Ricci F, Bianchi P E. Octyl 2-cyanoacrylate in sutureless surgery of extraocular muscles: an experimental study on the rabbit model.  Graefe&#39;s Arch Clin Exp Ophthalmol . 2000;238:454-458.     11. Gupta B K, Edward D, Duffy M T. 2-Octyl cyanoacrylate tissue adhesive and muscle attachment to porous anophthalmic orbital implants.  Ophthal Plast Reconstr Surg . 2001;17:264-269.     12. Burnstein A L, WuDunn D, Knotts S L, Catoira Y, Cantor L B. Conjunctival advancement versus nonincisional treatment for late-onset glaucoma filtering bleb leaks.  Ophthalmology . 2002;109:71-75.