Patent Publication Number: US-2023135924-A1

Title: Extendible implement from within a stiffening sleeve and tool body end

Description:
PRIORITY CLAIM 
     This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 63/263,166 titled “EXTENDIBLE IMPLEMENT FROM WITHIN A STIFFENING SLEEVE AND TOOL BODY END,” filed on Oct. 28, 2021, whose inventors are Reto Grüebler and Klaus Dorawa, which is hereby incorporated by reference in its entirety as though fully and completely set forth herein. 
    
    
     BACKGROUND 
     Over the years, many dramatic advancements in the field of minimally invasive surgical procedures have taken place. Accordingly, natural patient injury and healing times have been dramatically reduced. In the area of eye surgery as an example, previously inaccessible, injured or deteriorating tissue may be repaired or directly serviced through minimally invasive procedures. For example, regardless of the particular procedure, it is common that a vitrectomy will be included in at least part of the procedure. Vitrectomy is the removal of some or all of the vitreous humor from a patient&#39;s eye. In some cases, where the surgery was limited to removal of clouded vitreous humor, the vitrectomy may constitute the majority of the procedure. However, a vitrectomy may accompany cataract surgery, surgery to repair a retina, to address a macular pucker or a host of other issues. 
     In keeping with the example of eye surgery and a vitrectomy, the vitreous humor itself is a clear fibrous gel that may be removed by an elongated needle when inserted through a pre-placed cannula at the eye. More specifically, a vitrectomy probe is a surgical tool that is held by a surgeon at a gripping location with a needle emerging from the tool as described. The needle includes a central channel for removal of the vitreous humor. Further, the cannula provides a structurally supportive conduit strategically located at an offset location at the front of the eye, such as the pars plana. In this way, the probe needle may be guidingly inserted into the eye in a manner that avoids damage to the patient&#39;s lens or cornea. 
     The needle is generally guided and supported by a cannula and trocar assembly which has been prepositioned at the location of an incision through the pars plana as indicated. Thus, the needle may be securely advanced through to the interior of the eye to perform the surgical procedure. Of course, just as with a probe needle for a vitrectomy, a variety of other surgical implements may be similarly advanced through a cannula and trocar assembly for a variety of different surgical purposes. These may include forceps, scissors, light probe instruments and other instrumentation such as a scraper, backflush tool, or diathermy probe. 
     Over the years, minimally invasive surgeries, such as the described vitrectomies, have employed smaller and smaller implements for increasingly precise surgical maneuvers. For example, vitrectomy probe needles that traditionally may have been about 23 gauge may be about 25 or 27 gauge. This translates to reducing a needle diameter from just under about 0.5 mm (millimeters) to less than about 0.4 mm. Considering that a vitrectomy probe needle is likely to be of a few millimeters in length and hollow, this increasingly thin gauge implement is likely to be quite flexible. For other instruments, a similar flexibility issue emerges as the implement size becomes increasingly smaller, including for a vitrectomy probe cutter needle. 
     Increased pliability or flexibility for a surgical implement is not necessarily helpful to a surgeon during a procedure. Generally speaking, the surgeon is better aided by a degree of rigidity in the implement that affords a greater degree of control. That is, manual manipulation of the implement by the surgeon at an exterior location is more likely to reliably transfer to the surgical site if the implement is more inflexible. So, for example, in the case of a vitrectomy procedure, the probe may include a grip from which the needle extends toward and through the noted cannula structure at the eye. A larger and more rigid stiffening sleeve may extend from the structural support of the cannula and back toward the body and grip of the tool. Thus, at least in the space between the surgeon&#39;s grip location and the front of the eye, bending of the needle may be avoided/reduced due to the presence of the stiffening sleeve. Rather, a secure and reliably linear translation of movement from the grip to a pivot location at the surface of the eye is displayed (e.g. where the stiffening sleeve contacts the cannula). Once more, the actual length of the needle which presents within the eye and is not structurally bound by the stiffening sleeve is limited. Thus, bending of the needle is further minimized. 
     Unfortunately, utilizing a stiffening sleeve as detailed, places a notable surgical limitation on such a procedure. Specifically, a dimensional limitation is presented by the use of a sleeve. For example, where a 1 cm (centimeter) sleeve is utilized on a 3 cm needle, effectively 2 cm of working needle length is utilized for the procedure within the patient&#39;s eye. That is, in sandwiching the sleeve between the cannula and the grip location, securely maintaining the sleeve means that the needle is positioned right at 2 cm of depth into the patient&#39;s eye. Forcing the cannula deeper is not really possible without forcing injury to the eye at the cannula location. Once more, removing the needle to a shallower depth relaxes the stability of the sleeve, thus losing much of its supportive benefit. 
     Of course, where the targeted surgical location is greater than 2 cm from the cannula and eye surface, this means that utilizing the noted sleeve will prevent the necessary surgical access. By the same token, the target location may be well under 2 cm which could result in overshooting by the needle and eye injury to the patient. The targeted surgical location may also span a range of depths within the eye during the same procedure. 
     SUMMARY 
     A surgical tool is provided. The tool includes a body with an end that is manually secured by a surgeon for a surgical procedure. An implement of the tool extends from within the end to facilitate the procedure. A stiffening sleeve is provided about the implement for stabilization of the implement during the procedure. A biasing mechanism is coupled to the end of the tool body which allows for its retractability for guided extension of the implement in response to the stiffening sleeve contacting a cannula structure at a location adjacent the surgical procedure site. The biasing mechanism may be additionally coupled to the stiffening sleeve to guidably facilitate its retraction for still further extension of the implement. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a side perspective view of a surgical tool employing a needle aided by an embodiment of a dynamically extendable implement. 
         FIG.  2 A  is a side cross-sectional view of an end of the surgical tool of  FIG.  1    highlighting an internal biasing mechanism. 
         FIG.  2 B  is a side cross-sectional view of the tool end of  FIG.  2 A  with the end responsively shifted to extend the implement. 
         FIG.  3    is a side cross-sectional view of the tool end of  FIG.  2 B  with the implement further extended by a shift in position of a stiffening sleeve of the tool. 
         FIG.  4 A  is a side cross-sectional view of the tool end of  FIG.  1    employing an alternate embodiment of internal biasing mechanism. 
         FIG.  4 B  is a side cross-sectional view of the tool end of  FIG.  4 A  with the biasing mechanism fully collapsed for full extension of the implement. 
         FIG.  5 A  is an overview illustration of a surgical procedure performed with the tool of  FIG.  1    with the implement in an initial position. 
         FIG.  5 B  is an overview illustration of the surgical procedure of  FIG.  5 A  with the implement fully extended. 
         FIG.  6    is a flow-chart summarizing an embodiment of performing a minimally invasive surgical procedure with an implement aided by a dynamic extension. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the embodiments described may be practiced without these particular details. Further, numerous variations or modifications may be employed which remain contemplated by the embodiments as specifically described. 
     Embodiments are described with reference to certain types of surgical procedures. In particular, an overview of a vitrectomy probe is illustrated in  FIG.  1   . For example, vitreous humor removal, perhaps to address a vitreous hemorrhage, may be noted with reference to  FIGS.  5 A and  5 B . Of course, a forceps tool, scissors or any number of other optical surgical devices may employ extendible implement embodiments as detailed herein. These may include light probe instruments and other instrumentation such as a scraper, backflush tool, or diathermy probe. Further, while a vitrectomy procedure is largely discussed herein, embodiments of a vitrectomy probe as detailed herein may be utilized to address retinal detachments, macular pucker, macular holes, vitreous floaters, diabetic retinopathy or a variety of other eye conditions. Additionally, while vitrectomy and other eye surgeries often benefit from the use of fairly thin implements, other types of surgeries may benefit from the unique architecture and techniques detailed herein. Indeed, so long as a supportive stiffening sleeve is employed in combination with an implement or needle of extendible reach, appreciable benefit may be realized. 
     Referring now to  FIG.  1   , a side perspective view of a surgical tool  101  is shown employing an implement  175  in the form of a needle. As detailed herein, a surgical procedure performed with the tool  101  may be aided by the fact that the implement  175  is dynamically extendable. Specifically, the tool  101  for the embodiment shown, is a vitrectomy probe with a stiffening sleeve  100 . This sleeve  100  is configured to provide a supportive structure about the relatively thin implement  175  up to the point of contacting a cannula structure  530  as illustrated in  FIGS.  5 A and  5 B . Upon making such contact, the degree to which the implement  175  extends from within the sleeve  100  may be dynamically adjusted through various techniques detailed herein (note the extension (E)). In one embodiment, this may be achieved by the retraction of a tool body end  150  in general unison with the sleeve  100 , toward a proximal end or shell  125 . In this manner, a distance (d) is closed and the implement  175  is further extended as is detailed below. Indeed, with respect to the embodiment of  FIGS.  1 ,  2 A and  2 B , this generally unitary retraction of the end  150  and sleeve  100  together is the manner by which the increase in the extension (E) is attained. However, as is detailed further below, separate further retraction of the sleeve  100 , into an end orifice  130 , even after the closure of (d), for further increasing the extension (E) is additionally possible. 
     Continuing now with specific reference to  FIG.  1   , the needle or implement  175  is considered dynamically adjustable with respect to the degree of extension (E) due to the retractability of the tool end  160  as noted above as well as the stiffening sleeve  100  as detailed further below. In the embodiment shown, the tool  101  is a vitrectomy probe which may be utilized in a procedure as is also detailed further herein. However, other types of instruments for a variety of different surgical applications may take advantage of such dynamic adjustability. 
     The implement  175  may be relatively thin. In particular, it is not uncommon for a 25-35 mm long needle implement  175  to be higher than 25 gauge sizing. Thus, even where stainless steel or other suitably durable surgical materials are employed, the needle  175  alone may lack a desired rigidity from the surgeon&#39;s perspective and be prone to a degree of bending. 
     The noted lack of rigidity displayed by the needle  175  may be addressed by the inclusion of the illustrated sleeve  100  about the needle  175 . The illustrated sleeve  100  may extend from the tool  101  at its gripping element or end  150  a predetermined distance with a certain amount of needle extension (E). However, this may be intentionally adjusted by the surgeon over the course of a procedure. That is, the surgeon may advantageously exert control over how much sleeve support is provided versus how much reach or extension (E) may be attained by the needle implement  175 . This may take place in a dynamic fashion with the reach of the implement  175  changing throughout the course of a given surgical procedure. 
     Continuing with reference to  FIG.  1   , the tool  101  includes a proximal portion, rearward of the tool body end  150 , that may be referred to herein as a shell  125 . The shell  125  may be used as a form of ergonomic support or, in one embodiment, the shell  125  may be removable, depending on surgeon preference. For example, in the case of a vitrectomy probe, the surgeon may hold the instrument at the end  150 , between a thumb and index finger, with the shell  125  resting at the perlicue of the hand and protectively encasing instrument components therein. The implement  175  may support a cutter therein which interacts with a port  177  thereof for the controlled uptake of vitreous humor as described further below. For such a procedure, it is the dynamic extendability (E) of the implement  175  from within the sleeve  100  and end  150  that uniquely supports and facilitates the surgeon&#39;s efforts in this endeavor. 
     Referring now to  FIG.  2 A , a side cross-sectional view of an end  150  of the surgical tool  101  of  FIG.  1    is shown highlighting an internal biasing mechanism  220 . In the embodiment illustrated, the mechanism  220  is a spring anchored within a biasing chamber  225  to act against a base  230  of the sleeve  100  within the tool end  150 . With the base  230  secured to the tool end, force applied to the base  230  by the sleeve  100  may act to shift the position of the end  150  and close the distance (d). Indeed, with added reference to  FIG.  2 B , this has occurred with the end  150  meeting the shell  125  as noted at  200 . With the sleeve  100  and the end  150  shifting as indicated, there may be a corresponding increase in the extension (e.g. from (E) of  FIG.  2 A  to (E′) of  FIG.  2 B ). 
     Increasing the extension by an amount equal to the eliminated distance (d) (i.e. to E′) may be a matter of surgical preference as the distal end of the sleeve  100  interacts with a cannula structure  530  as detailed below with respect to  FIGS.  5 A and  5 B . Thus, the surgeon is able to dynamically extend the length of the needle implement  175  by perhaps a few millimeters in a steady manner as guided by the resisting biasing mechanism  220 . Thus, a controlled manner of extending the reach of the instrument for a surgical procedure may be available. 
     Note that another internal spring  240  and other components of the tool  101  are illustrated in  FIGS.  2 A and  2 B . These may be employed for other purposes, such as actuating forceps or scissors where other types of implements are utilized. However, in other embodiments detailed below, such internal components may be utilized to aid in even further extension of the implement  175 . 
     Referring now to  FIG.  3   , a side cross-sectional view of the tool end  150  of  FIG.  2 B  is illustrated in an embodiment where the implement  175  may be further extended (e.g. to (E″)). For example, in this embodiment, even after the shift in position of the end  150  to meet the shell  125  as described above, the base  230  may be shifted by an additional distance (d″) to attain the added extension (E″). For example, in one embodiment, added force applied by the surgeon may be used to attain shearing of the base  230  from the tool end  150  to allow for additional compression of the biasing mechanism (spring  220 ). So, for example, with added reference to  FIGS.  5 A and  5 B , once a predetermined force is applied by the surgeon, directed at the contact point of the sleeve  100  and cannula  530 , the shearing and additional shifting of the sleeve  100  apart from the end  150  may be attained. In this manner added reach of the implement  175  into a patient&#39;s eye  550  may be achieved (e.g. to the added extension (E″) shown). Alternatively, different internal architecture may be employed as detailed below to attain the added extension (E″) without requirement any requirement of shearing (see  FIGS.  4 A and  4 B  discussed below). 
     Referring now to  FIG.  4 A , a side cross-sectional view of the tool end  150  of  FIG.  1    is illustrated for which an alternate embodiment of internal biasing mechanism is utilized. In this case, rather than employing a single spring  220  within a biasing chamber  225 , as illustrated in  FIGS.  2 A and  2 B , another proximal chamber  425  of differing architecture is also employed. In this way, successive shifting or closures of different chambers  225 ,  425  may be utilized to achieve the full extension (E″) of  FIG.  4 B . As detailed below, utilizing discrete chambers  225 ,  425  for successive shifting and extension of the implement  175  means that shearing for sake of movement of the base  230  to achieve the full extension (E″) may be avoided. 
     Continuing with reference to  FIG.  4 A , the end of the sleeve  100  is again configured to contact a cannula  530  as illustrated in  FIGS.  5 A and  5 B , as a manner of initiating a shift of the tool end  150  in order to close the distance (d). This is again visible with respect to the contact between the end  150  and the shell  125  as shown in  FIG.  4 B  (see contact point  200 ). In order to attain this shifting of the tool end  150 , the proximal chamber  425  is closed. Note that some level of resistance to this closure is provided for overall stability of the tool  101 . For example, there may be little to no clearance between the end  150  and underlying housing  400  of the tool  101 . Indeed, in one embodiment, a predetermined degree of frictional resistance between these features  150 ,  400  may be provided or even air pressure, another spring or other suitable resistance located within the proximal chamber  425 . So long as the resistance is of a lesser force than the spring  420  that runs through the biasing chamber  420 , the proximal chamber  425  will close in advance of shifting of the base  230  and further implement extension described below. Thus, for the embodiment illustrated, extension of the implement  175  may begin in sequence with shifting of the end  150  to close the proximal chamber  425  and the distance (d). 
     Referring now to  FIG.  4 B , the biasing mechanism spring  420  that runs through both chambers  225 ,  425  is now shown compressed, with the base  230  having subsequently shifted after the closure of the proximal chamber  425  and initial distance (d) of  FIG.  4 A . That is, another distance (d′) has now also been closed to further extend the implement to the extension position illustrated (E″). Indeed, the amount of additional reach now provided to the implement  175  is a distance (D) that is roughly equal to the initial end closure distance (d) plus the subsequent distance (d′) of the shifting of the base  230 . That is, with added reference to  FIGS.  5 A and  5 B , once the sleeve  100  is in contact with the cannula  530 , an initial shift of the end  150  may be controllably exerted by the surgeon to attain an initial extended reach of the implement  175  into the eye  550  for a procedure (e.g. as the end  150  closes the proximal chamber  425  and distance (d)). This reach may be further extended by the surgeon through application of some degree of added force (e.g. as the base  230  travels over the distance (d′)). 
     It is worth noting that there is no particular requirement that the sequence of shifting occur as indicated above. For example, in another embodiment, the travel of the base  230  may face a lesser degree of resistance and occur as the initial manner of extending the implement  175 . In this embodiment, closure of the proximal chamber  425  and the distance (d) of  FIG.  4 A  may occur after the travel of the base  230  as described. Furthermore, these movements may occur in relative unison with neither being particularly more or less resistant to the extension of the implement  175  than the other. Regardless, so long as both end  150  and internal base  230  travel movements are cumulatively attainable, the surgeon is afforded an added degree of reach for the implement  175  that may be beneficial to the surgery as described below. 
     Referring directly now to  FIGS.  5 A and  5 B , an overview illustration of a surgical procedure performed with the tool  101  of  FIG.  1    is shown. More specifically, the reach of the tool implement  175  into a patient&#39;s eye  550  is extended from an initial position (E) to a fully extended position (E″) in a multifaceted manner. For embodiments herein this includes the shifting of a tool end  150  in a proximal direction in unison with a sleeve  100  over the implement  175 . Further, the sleeve  100  may be supplementally shifted proximally within the end  150  for added reach of the implement  175 . 
     Continuing with reference to  FIGS.  5 A and  5 B , a side cross-sectional overview of a patient&#39;s eye  550  is shown wherein the procedure is a vitrectomy procedure. During the procedure, the implement  175  of the tool  101  is inserted through a preplaced cannula  530  and directed toward a region  510  where vitreous humor is to be removed. A suction is applied and the port  177  is used for the uptake of the vitreous humor or other substances. For example, in the procedure illustrated, a hemorrhage may be taking place in the region  510  such that blood is drawn into the port  177  along with the vitreous humor. 
     Notice that while the needle  175  reaches into the interior of the eye  550  for the procedure as described, the stiffening sleeve  100  which surrounds the needle  175  does not. Rather, the end of the sleeve  100  is securely rested at the internal structure of the cannula  530 . More specifically, the interior cannula structure may be of a funnel shaped or other accommodating morphology so as to receive and support the end of the stiffening sleeve  100  during the procedure. By the same token, the center of the cannula  530  includes an orifice of sufficient size to allow passage of the needle  175  therethrough. Of course, the orifice would also be too small to allow the same passage of the sleeve  100 . So, for example, in one embodiment, the orifice may be about 0.475 mm in diameter so as to allow for passage of a 26 gauge and smaller needle  175  (e.g. 0.46 mm diameter or smaller). At the same time, this orifice would also prevent passage of a 25 gauge and larger sleeve  100  (e.g. 0.515 mm diameter or larger). Of course, a variety of different dimensional combinations may be employed so as to promote needle implement passage and prohibit sleeve passage through an orifice of the cannula  530  as described. 
     With the sleeve  100  stably interfacing the interior structure of the cannula  530 , the surgeon may steer the needle about a pivot point at the cannula  530 . In this manner a certain stabilized working area is attained with the needle  175  at the interior of the eye  550 . Further, between the cannula  530  and the tool  101  of  FIG.  1   , where unintended bending might otherwise be of concern, supplemental stiffness is provided by the sleeve  100 . 
     As alluded to above, for the example of a vitrectomy procedure, a cutter is reciprocating within the needle implement  175  during this delicate procedure. The surgery illustrated also includes a light instrument  525  reaching into the eye  550  through another cannula. In both circumstances, the cannulas  530  are positioned in an offset manner at the sclera  570 . In this way, the more delicate cornea  590  and lens  580  may be avoided. 
     By the same token, the optic nerve and retina, located out of view at the back of the eye  550 , are also quite delicate. With this in mind, the stiffening sleeve  100  may play an initial role in preventing the needle implement  175  from unintentionally reaching too far into the eye  550 . By the same token, however, the surgeon may exert an intentional force such that the implement  175  guidingly and controllably achieves an extended reach (E″) as illustrated here according to the techniques detailed above. 
     Referring now to  FIG.  6   , a flow-chart summarizing an embodiment of performing a minimally invasive surgical procedure with an implement having dynamic extendible reach is illustrated. As indicated at  615 , a cannula is positioned at an outer location of a patient&#39;s eye to provide supportive structure for a surgical procedure. An implement such as a needle of a surgical tool may be guided through an orifice of the cannula as noted at  630 . Thus, the needle may extend from the surgical tool and beyond the cannula toward a surgical site. However, as indicated at  645 , a stiffening sleeve of the tool that is located about the needle may be used to stabilize the tool at the cannula and hold the implement needle in position. 
     With the above scenario in place for a surgical procedure, the reach of the implement may be extended further toward the surgical site from the initial sleeve supported position (see  660 ). Specifically, this may occur by way of a retraction of a tool end as indicated at  675  which also effects a commensurate sleeve retraction for sake of increasing implement reach. Furthermore, the sleeve may undergo an additional degree of retraction beyond the tool end retraction (see  690 ). As detailed hereinabove, these modes of retraction may occur independently or in sequence with the tool end retraction preceding the independent sleeve retraction (or vice versa). Further, these cumulative retractions may take place in a relatively simultaneous or overlapping manner. So long as multiple modes of retraction are available for cumulative enhancement of implement reach, appreciable benefit may be available to the surgeon for sake of the procedure. 
     Embodiments described hereinabove include architecture and techniques that allow for practical use of a stiffening sleeve to support a surgical procedure employing a relatively thin surgical implement. However, rather than remain reliant on the length of the stiffening sleeve to determine surgical access with the implement, multiple cumulative modes of extending reach of the implement toward an interior surgical site may be employed as indicated above. 
     The preceding description has been presented with reference to presently preferred embodiments. However, other embodiments and/or features of the embodiments disclosed but not detailed hereinabove may be employed. Furthermore, persons skilled in the art and technology to which these embodiments pertain will appreciate that still other alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle and scope of these embodiments. Additionally, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.