Patent Publication Number: US-2019167415-A1

Title: Surgical tool and method

Description:
INCORPORATION BY REFERENCE 
     The following document is incorporated by reference as if fully set forth herein: U.S. Provisional Application 62/594,848, filed Dec. 5, 2017. 
    
    
     FIELD OF INVENTION 
     The present invention generally relates to a medical device, and more particularly relates to a surgical tool. 
     BACKGROUND 
     Ophthalmic surgery requires precise tools and reliable methods to minimize trauma to the anterior chamber of the patient&#39;s eye. One type of ophthalmic surgery is Descemet membrane endothelial keratoplasty (DMEK) surgery. DMEK is a cornea transplant procedure that involves selective removal of the patient&#39;s Descemet membrane and endothelium, without any stroma, followed by the transplant of donor corneal endothelium and Descemet membrane donor tissue. DMEK is considered a partial thickness corneal transplant surgery which primarily replaces the innermost portion of the cornea rather than the full thickness of the cornea. DMEK surgery has the advantage of providing more rapid visual recovery, lower donor tissue rejection rates, and better refractive outcomes than procedures using thicker corneal donor tissue containing the stroma and other corneal layers. The donor tissue for DMEK surgery is considerably thinner in comparison to tissues used in other corneal transplant procedures, measuring approximately 10-15 microns thick. Because the donor tissue is thin and has no stroma attached, it is susceptible to being flimsy and to scrolling upon itself, which creates a challenge when attempting to prepare, handle, transfer, and properly place and position the donor tissue in the anterior chamber of the patient&#39;s eye. 
     Known methods for performing this surgery include injecting a donor tissue into the patient&#39;s eye through a single port. As shown in  FIG. 1 , one type of surgery according to the prior art involves a relatively larger gauge tool  1  that injects a donor tissue into the eye  2  via a single port  3 . This type of surgery requires a relatively larger incision, typically 3.2-4.0 mm in length, to accommodate injecting the donor tissue. This larger incision may require the application of sutures in order to be closed. Other known methods and tools for DMEK surgery do not provide a reliable configuration for orienting and unscrolling a donor tissue once implanted in a patient&#39;s eye. Known methods for promoting unscrolling and orientation of the donor tissue, such as repeated tapping of the patient&#39;s eye, twisting the insertion devices, etc., are time consuming, less reliable, and may lead to damage of the donor tissue. 
     Accordingly, there is a need for a reliable surgical tool and method that is less invasive, more efficient for unscrolling the donor tissue, and reduces the chance of causing trauma to the patient&#39;s eye and the donor tissue during the procedure. 
     SUMMARY 
     Briefly stated, a surgical tool assembly and a surgical method are disclosed that reliably, quickly, and correctly orients, unscrolls, and accurately places a donor tissue implanted into the anterior chamber of a patient&#39;s eye. 
     The surgical tool assembly includes a forceps instrument including a proximal handle portion with an actuator, and a distal forceps portion including jaws. The actuator selectively moves the jaws between an open position and a closed or gripped position. The surgical tool assembly includes an infusion assembly including a tube configured to be connected to a fluid source at a primary (first) tube end and connected to a fitting at a paracentesis (second) tube end. The fitting defines a passage configured to receive the distal forceps portion of the forceps instrument. An infusion sleeve extends away from the fitting. The infusion sleeve is arranged concentric around an outer surface of the distal forceps portion to define a fluid pathway. The jaws extend beyond a terminal end of the infusion sleeve such that the jaws are arranged outside of the infusion sleeve. 
     A method of performing corneal surgery is also disclosed. The method includes providing a surgical tool assembly comprising a forceps instrument including a proximal handle portion with an actuator, and a distal forceps portion including jaws. The actuator moves the jaws between an open position and a closed or gripped position. The surgical tool assembly includes an infusion assembly including a tube configured to be connected to a fluid source at a primary tube end and connected to a fitting at a paracentesis tube end. An infusion sleeve extends away from the fitting, and the fitting defines a passage configured to receive the distal forceps portion of the forceps instrument. The infusion sleeve is arranged concentric around an outer surface of the distal forceps portion to define a fluid pathway. The jaws extend beyond a terminal end of the infusion sleeve such that the jaws are arranged outside of the infusion sleeve. A donor tissue preparation tool (a holder) is configured to support a donor tissue. The donor tissue will be positioned in a scrolled orientation (a scroll) on the donor preparation tool with the endothelial surface facing inward. The method includes cutting two incisions on the anterior chamber of the patient&#39;s eye. The method includes placing the donor tissue on the donor tissue preparation tool and positioning the donor tissue preparation tool adjacent to the primary incision (a 2.0-2.5 mm incision). The method includes inserting the distal forceps portion of the forceps instrument through the paracentesis incision (a 1.0-1.5 mm incision), through the anterior chamber of the patient&#39;s eye and out of the primary incision. The method includes securing the donor tissue from the donor tissue preparation tool via the jaws and withdrawing the distal forceps portion back through the primary incision and into the anterior chamber of the patient&#39;s eye at the implant site. Finally, the method includes providing pressurized fluid to the fluid pathway of the infusion sleeve while gripping the donor tissue to orient, unscroll, and accurately place the donor tissue at the implant site. While holding the donor tissue in position, a small amount of fluid is aspirated to shallow, i.e. to decrease the volume of, the anterior chamber of the patient&#39;s eye to prevent the donor tissue from scrolling. 
     Additional features of the surgical tool assembly and the method are described in more detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of preferred embodiments of the present invention, and are not intended to limit the invention as encompassed by the claims forming part of the application, wherein like items are identified by the same reference designations: 
         FIG. 1  is an illustration of a surgical tool and method according to the prior art. 
         FIG. 2A  is a perspective view of a surgical tool assembly according to one embodiment in an assembled state. 
         FIG. 2B  is a magnified view of the surgical tool assembly of  FIG. 2A . 
         FIG. 3  is a magnified view of the surgical tool assembly in a disassembled state. 
         FIG. 4  is a perspective view of a forceps instrument and an infusion assembly of the surgical tool assembly. 
         FIG. 5  is a magnified view of the forceps instrument and the infusion assembly of the surgical tool assembly. 
         FIGS. 6A-6F  illustrate steps for performing a surgical procedure according to one embodiment. 
         FIG. 7A  illustrates an alternative arrangement of the surgical tool assembly. 
         FIG. 7B  is a magnified view of the infusion assembly of  FIG. 7A . 
         FIG. 7C  is a magnified view of the forceps instrument of  FIG. 7A . 
         FIG. 7D  is an alternative view of the surgical tool assembly of  FIG. 7A . 
         FIG. 7E  is a magnified view of an interface of the forceps instrument and infusion assembly of  FIG. 7A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in a variety of views in  FIGS. 2A-5 , a surgical tool assembly  10  is provided. The surgical tool assembly  10  is preferably used for Descemet membrane endothelial keratoplasty (DMEK) surgery. One of ordinary skill in the art would recognize from this disclosure that the surgical tool assembly  10  can used for other surgeries. The surgical tool assembly  10  includes a forceps instrument  12  with a proximal handle portion  14  including an actuator  16 , and a distal forceps portion  18  including jaws  20 . In one embodiment, the distal forceps portion  18  has a pre-formed curvature; however, one of ordinary skill in the art would recognize that the distal forceps portion  18  could have no curvature or be made of a bendable material that can curve, without departing from the spirit or subject matter of this application. The actuator  16  is configured to selectively move the jaws  20  between an open position and a closed or gripped position. In one embodiment, gripping the actuator  16  closes the jaws  20 , and the jaws  20  have a default open position when the actuator  16  is not engaged or gripped. One of ordinary skill in the art would recognize from the present disclosure that other types of actuators  16  and jaws  20  can be used, without departing from the spirit or subject matter of this application. 
     An infusion assembly  22  includes a tube  24  configured to be connected to a fluid source  26  (shown schematically) at a primary tube end  28  and connected to a fitting  30  at a secondary or paracentesis tube end  32 . In one embodiment, the fluid provided by the fluid source  26  is saline. One of ordinary skill in the art would recognize from the present disclosure that other fluids can be used for the surgical procedure and also based on the operator&#39;s preference. The fitting  30  defines an internal passage configured to receive the distal forceps portion  18  of the forceps instrument  12 . In one embodiment, the passage of the fitting  30  is press-fit onto the distal forceps portion  18 . One of ordinary skill in the art would recognize from the present disclosure that the fitting  30  can be attached to the distal forceps portion  18  in a variety of ways. The present embodiments disclosed herein provide a combined tool assembly  10  wherein the forceps instrument  12  and the infusion assembly  22  are connected to each other. 
     An infusion sleeve  34  extends away from the fitting  30 , and defines an inner passage, such that the infusion sleeve  34  can be arranged concentric around an outer surface of the distal forceps portion  18  to define a fluid pathway. The jaws  20  extend beyond a terminal end  36  of the infusion sleeve  34  such that the jaws  20  are arranged outside of the infusion sleeve  34 . In one embodiment, the inner diameter of the infusion sleeve  34  is 470-600 microns, and is more preferably 520-550 microns. In one embodiment, an outer diameter of the distal forceps portion  18  in a region away from the jaws  20  is 300-500 microns. The infusion assembly  22  provides fluid from the fluid source  26  to the terminal end  36  of the infusion sleeve  34  directly to a region of the jaws  20 . Due to the infusion sleeve  34  concentrically surrounding the distal forceps portion  18 , the infusion sleeve  34  provides pressurized fluid 360° around the jaws  20 . In one embodiment, the jaws  20  having a gripping force capable of reliably holding a weight of 20 grams in suspension. In one embodiment, fluid provided to the terminal end  36  of the infusion sleeve  34  is at 1.0-30.0 psi. The gripping force of the jaws  20  is greater than a pressure level of fluid from the fluid source  26  to the infusion sleeve  34  to provide a reliable arrangement for securing a donor tissue  40  in position while injecting fluid around the jaws  20  to unscroll a donor tissue  40 . 
     In one embodiment, the surgical tool assembly  10  includes a donor tissue preparation tool  38  configured to support a donor tissue  40 . In one embodiment, the donor tissue preparation tool  38  is a spoon-like tool including a circular head portion  42  for supporting the donor tissue  40 . As shown in  FIGS. 2A and 2B , a groove  41  is provided on the donor tissue preparation tool  38  in one embodiment. The groove  41  is provided to reliably position the donor tissue  40  in a central portion of the donor tissue preparation tool  38 . The groove  41  also functions to allow better ability to grasp an edge of the tissue with the forceps prior to pulling the tissue into the eye. In other embodiments, the donor tissue preparation tool  38  is a funnel guide tool, a spatula tool, forceps, or other known surgical tool capable of holding the donor tissue  40 . For example, in one embodiment the donor tissue preparation tool  38  is a funnel guide, such as a Busing funnel guide (as disclosed in: https://www.surgicalinstruments.com/browse-by-type/product/16562-busin-glide-for-corneal-endo-implantation, [last visited Oct. 16, 2017] which is incorporated by reference as if fully set forth herein). One of ordinary skill in the art would recognize from the present disclosure that alternative types of donor tissue preparation tools can be used within the spirit of the subject matter of this application. 
     In one embodiment, the infusion assembly  22  is disposable, and the forceps instrument  12  and the donor tissue preparation tool  38  are reusable. As used herein, the term “disposable” with respect to the components of the assembly  10  indicates a component that is relatively inexpensive such that it is economically feasible to be discarded after a single use. In contrast, the term “reusable” indicates a component that is relatively expensive such that it is not economically feasible to be discarded after a single use. By providing an assembly  10  wherein a portion of the components are disposable, i.e. the infusion assembly  22 , the overall costs of the assembly  10  is reduced. In another embodiment, the infusion assembly  22  and the donor tissue preparation tool  38  are disposable. In one embodiment, the infusion assembly  22  is formed from plastic. In one embodiment, the donor tissue preparation tool  38  is formed from metal, and is preferably formed from steel or titanium. 
     In one embodiment, a method of performing corneal surgery is provided. In an embodiment the corneal surgery is DMEK surgery.  FIGS. 6A-6F  illustrate the steps of performing corneal surgery. The method includes providing the surgical tool assembly  10  described above including the forceps instrument  12 , the infusion assembly  22 , and the donor tissue preparation tool  38 . The method includes forming two incisions  44   a ,  44   b  (i.e. a primary incision  44   a  of 2.0-2.5 mm and a paracentesis incision  44   b  of 1.0-1.5 mm) into the anterior chamber of the patient&#39;s eye  46 . The incisions are made in the cornea, and allow access to the anterior chamber. These incisions can be made using any known cutting method. As shown in the drawings, the two incisions  44   a ,  44   b  are on diametrically opposed hemispheres of the anterior chamber of the patient&#39;s eye  46 . Each of the incisions  44   a ,  44   b  are less than 2.5 mm. In one embodiment, incision  44   a  has a length of 2.0-2.5 mm. In one embodiment, incision  44   b  has a length of 1.0-1.5 mm. In one embodiment, the primary incision  44   a  is larger than the paracentesis incision  44   b . Neither of the incisions  44   a ,  44   b  requires a suture to be closed due to the relatively small dimensions of the incisions  44   a ,  44   b . One of ordinary skill in the art recognizes that an original cornea tissue can be removed from the anterior chamber of the patient&#39;s eye  46  during any step prior to implanting the donor tissue  40  in the anterior chamber of the patient&#39;s eye  46 . 
     The method includes placing the donor tissue  40  on the donor tissue preparation tool  38  in a trifold orientation with endothelium inward and positioning the donor tissue preparation tool  38  adjacent to the primary incision  44   a . As shown in  FIG. 6A , the circular head portion  42  of the donor tissue preparation tool is directly adjacent to the primary incision  44   a  of the anterior chamber of the patient&#39;s eye  46 . As shown in  FIG. 6B , the method includes inserting the distal forceps portion  18  of the forceps instrument  12  through the paracentesis incision  44   b , through the anterior chamber of the patient&#39;s eye  46 , and out of the primary incision  44   a . As shown in  FIG. 6C , the method includes securing the donor tissue  40  from the donor tissue preparation tool  38  via the jaws  20 . As shown in  FIG. 6D , the method includes withdrawing the distal forceps portion  18  back through the primary incision  44   a  and into the anterior chamber of the patient&#39;s eye  46  at an installation site. In one embodiment, this step includes gripping a circumferential edge of the donor tissue  40  with the jaws  20 . 
     Although the orientation of the donor tissue preparation tool  38  and the donor tissue  40  are shown in one orientation in  FIGS. 6A-6E , one of ordinary skill in the art would recognize from the present disclosure that the orientation of these components can change relative to the patient&#39;s eye. For example, the orientation of the donor tissue preparation tool  38  and the donor tissue  40  can be rotated 90 degrees relative to the patient&#39;s eye. In one embodiment, a longitudinal axis of the folded tissue  40  can be aligned with the groove  41  of the donor tissue preparation tool  38 . 
     In one embodiment, the donor tissue  40  has an outer diameter that is greater than a length of the incisions  44   a  such that the donor tissue  40  folds (i.e. scrolls) onto itself when being pulled back through the primary incision  44   a . This ensures that the incisions  44   a  and  44   b  have minimal dimensions, and therefore minimizes trauma to the anterior chamber of the patient&#39;s eye  46 . A surgeon or medical professional can manipulate the surgical tool assembly  10  by selectively gripping the actuator  16  to grab the donor tissue  40  with the jaws  20 . By inserting the distal forceps portion  18  in one incision  44   b  and out of the other incision  44   a , and then pulling the gripped donor tissue  40  backwards into the anterior chamber of the patient&#39;s eye  46  through the primary incision  44   a , this method avoids “injecting” the donor tissue  40  into the anterior chamber of the patient&#39;s eye  46 , which typically requires a larger incision. 
     As shown in  FIGS. 6E and 6F , the method includes providing pressurized fluid  50  to the fluid pathway of the infusion sleeve  34  while gripping the donor tissue  40  to orient and unscroll the donor tissue  40  (shown in the unscrolled state as donor tissue  40 ′) at the installation site inside the anterior chamber of the patient&#39;s eye  46 . This method provides a much faster and more reliable configuration to unscroll the donor tissue  40 ′ within the anterior chamber of the patient&#39;s eye  46 . According to one embodiment, the method can unscroll the donor tissue  40 ′ in less than sixty seconds. While holding the donor tissue in position, a small amount of fluid is aspirated to shallow, i.e. to decrease the volume of, the anterior chamber of the patient&#39;s eye to prevent the donor tissue from scrolling. In one embodiment, a plunger of a syringe is driven in a first direction to infuse the pressurized fluid into the anterior chamber of the patient&#39;s eye. After the pressurized fluid is provided, the aspiration step is performed by a user withdrawing the plunger of the syringe, which effectively decreases the volume of the anterior chamber of the patient&#39;s eye and helps set the donor tissue in position. One of ordinary skill in the art would understand that the aspiration step can be performed by a variety of configurations. 
       FIG. 7A-7E  illustrate an alternative embodiment of the surgical tool assembly. The embodiment shown in  FIGS. 7A-7E  is functionally identical to the features described herein with respect to the other embodiments. As shown in  FIG. 7A , the handle of the forceps instrument  112  is different than the forceps instrument  12  illustrated in the other drawings. The handle includes two wings or prongs for the actuator  116 , best shown in  FIGS. 7D and 7E . The infusion assembly  122  includes a fitting  130  with a tubular engagement portion  135  that is adapted to engage around an outer surface of the forceps instrument  112 . The secondary or paracentesis tube end  132  and the infusion sleeve  134  perform the same function as the corresponding parts described herein. The forceps instrument  112  includes a distal forceps portion  118  with jaws  120 . 
     A secondary sealing component  170  between the forceps instrument  112  and the infusion assembly  122  is illustrated in  FIG. 7E . A sleeve  170  is provided between the forceps instrument  112  and the infusion assembly  122 , and wraps around an outer surface of each of these components. The sleeve  170  provides a reliable seal between the forceps instrument  112  and the infusion assembly  122 . Other features of the forceps instrument  112  and the infusion assembly  122  are functionally the same as the features described above with respect to the forceps instrument  12  and the infusion assembly  22 . 
     The forgoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying claims, that various changes, modifications, and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.