Tissue Retractor
A tissue retractor device for retracting tissue is disclosed. The device includes a base connected to a plurality of blades distributed around the base. Each of the blades is outwardly movable from the base. A pusher is engaged to the base. The pusher is movable in a longitudinal direction to move the blades to angularly displace each of the blades from a respective closed position to an open position. At least one biasing device is engaged with the base that biases the respective ones of the blades toward a closed position. The closed position is where the blades are relatively close together with respect to the open position.
This application is a Divisional of U.S. patent application Ser. No. 13/657,516 filed on Oct. 22, 2012, titled “Tissue Retractor” to Alan G. Ellman, all of which is incorporated herein by reference.
FIELDThis present application relates to a surgical tissue retractor.
BACKGROUNDThe present invention relates to a device and method for expanding an enclosure such as tissue to expose the operative field in a patient. Entering an operative field such as in connection with specialized back surgery on or in-between vertebrae of the spine and on spinal discs involves various meticulous surgical procedures which can be challenging even for experienced surgeons who specialize in this particular surgery. Minimally invasive techniques are preferred over traditional open surgical procedures which require extensive operating time and post-operative recovery time.
When employing such minimally invasive surgical techniques, one of the challenging requirements relates to safe retraction of patient tissue in the target area or operative field to provide sufficient space for implementation of these techniques. For example, nerve roots are plentiful in this operative field and extreme care must be exercised by the surgeon to avoid accidentally damaging or even severing any of these roots when retracting tissue in this operative field. An example of a tissue retractor which does not include improvements, advancements and advantages of the present invention is provided in U.S. Pat. No. 7,374,534 issued on May 20, 2008 to Dalton, which is incorporated herein by reference in its entirety. The present invention provides an improved retractor device which improves chances of avoiding undesired results and thereby greatly improves chances of achieving a successful patient outcome. Furthermore, the present invention provides greater control, precision, ease of use and may have utility in surgical procedures performed in operative fields other than those discussed herein. Other advantages and features will become apparent from the description of the invention.
SUMMARYIn summary, an embodiment of relates to a tissue retractor device and/or to a method for performing a surgical procedure using that device on a patient by a surgeon. The device includes a base hinged to a number of blades circumferentially distributed around the base. In one embodiment, each of the blades is spring-biased so that the blades close upon themselves in the default state. Each of the blades is rotatable relative to its respective hinge when utilizing the retractor device under the control of the surgeon. In one embodiment, one of the blades is longer than all of the other blades, thereby providing an advantageously-smaller device-tip configuration by which the surgeon can better control such longer blade to maneuver around, and between, nerve roots and other critical elements lying in its path after the device has been surgically inserted into the patient.
In one aspect, the device further includes a pusher mechanism which is threadably and concentrically connected within the base. Again, after the device has been surgically inserted into the patient, the pusher interacts with the blades in a manner to controllably and angularly displace each of the blades from its respective closed position about its respective hinge, responsive to the surgeon's manually-rotating the pusher in the threaded connection relative to the base.
To facilitate the surgical insertion or implantation of the device, the device further includes a dilator mechanism thread-ably and concentrically connected within the pusher. The dilator, in one embodiment, includes a concentrically located shaft having a tip at the end of the shaft which protrudes beyond the end of the largest one blade. The dilator tip is suitable for penetrating or pushing into the body of the patient while each of the blades is in its respective closed position and before the surgeon operates the pusher to displace the blades. And, the tip is particularly suitable for maneuvering between adjacent vertebrae in the spine of the patient if back surgery is being performed. However, it will be understood that the present embodiment may be used in broader surgical procedures beyond spinal surgery including OB/GYN, or even non-surgical procedures where one desires to expand a particular area.
In another embodiment, a method relates to first inserting a guide-wire into the spinal area of a patient to a desired depth. Then the above-described tissue retracting device including the dilator having a tip protruding beyond any other structure of that device is slid over the guide-wire. The device is inserted into the patient to a desired depth, the surgeon maneuvering the tip between target vertebrae, the maneuvering including clockwise and counter clockwise rotation of the device while the blades remain closed. Under certain circumstances, the guide-wire may be removed from the patient, either prior to, concurrently with, or subsequent to the dilator tip maneuvering. However, if the guide-wire was not previously removed, after the dilator tip is properly positioned (wherefore ends of the blades are properly positioned), the dilator and the guide-wire are both removed together from the device, leaving an inserted portion of the remainder of the device including at least a portion of its blades in the patient. The non-inserted portion includes the accessible circularly-shaped base noted above, hinged to the inserted blades, where one of the blades is longer than the other two equally-sized blades. The surgeon maneuvers the one blade beyond and around nerve roots that are in the vicinity of the target vertebrae, thereby safely clearing a pathway between and amongst those nerve roots which otherwise obstruct the surgeon's performance. The surgeon then operates the pusher mechanism by rotating its knob relative to the base and controllably displaces each of the blades from its respective closed position to cause tissue of the patient's body to be retracted. This provides space at the location of the operative field for surgical activity. Finally, the surgeon inserts a surgical tool, perhaps inserting one of several tools in sequence, into the device when the device's blades are displaced, and uses each such tool to perform the necessary surgery.
In this description, the same reference numeral in different Figs. refers to the same entity. Otherwise, reference numerals of each Fig. start with the same number as the number of that Fig. For example,
Base 11 can be a circular structure and includes screw-threads formed therein (threads 180 in
In the present embodiment, three retractor blades 12 are spaced circumferentially around base 11. Each blade 12 includes extended portion 12a and hinge portion 12b, wherein each blade 12 is hinged by a respective hinge-pin 13 (located in hinge portion 12b, to base 11. One skilled in the art, however, will understand that any number of blades 12 may be employed. In one embodiment, blades 12 are spring-biased toward a closed position, as shown, by springs 19. Each blade has its own spring 19 associated with its respective hinge pin, and discussed in further detail below. Although the use of independent coil springs are shown in the respective figures, one skilled in the art will readily understand that alternative spring means may be employed. For example, elastic membranes or materials (rubber for example) may be used in place of the springs. In one embodiment, an elastic washer (e.g., an O-ring) is circumferentially disposed, encircling areas between base 11 and hinge portion 12b of all three hinge portions 12. Thus, when any of the blades is moved into an open or retracted position, the washer provides elastic force in response thereby biasing the blades 12 toward their closed position. The use of a singular O-ring may have advantages in manufacturing costs or assembly. In another alternative embodiment, the blades 12 may be molded together with base 11 with a plastic material where the blades are biased inward based on the elasticity of the plastic material used.
Pusher mechanism 14 is threadably engaged to base 11 for movement in and out thereof. The Pusher mechanism 14 is manually rotatable by grasping by a user (e.g., a surgeon, aid, or device) and turning knob finger tabs 15. In an alternative embodiment, the dilator mechanism (including knob 16) may be welded to pusher mechanism 15. Operation of the entire retractor device including the pusher mechanism shall be discussed below.
Dilator mechanism knurled knob 16 (hereinafter knob 16) is threadably engaged with pusher mechanism 15, similar to the thread-able engagement between pusher 15 and base 11, and is shown in
With reference to
Different retractors can be designed for different surgical tasks. Different retractors can have different outward blade displacement limits as functions of different pusher tube lengths and/or as functions of different degrees of taper of section 51. Typically, these displacements may be in the two (2) to twelve (12) millimeter range, but is not limited to any particular displacement amount. The more severe the taper of section 51, the greater the blade displacement is obtained per angle of rotation of pusher tabs 15. With other parameters being equal, however, a greater taper to section 51 yields a greater effort than otherwise is required by the user in rotating pusher tabs 15 to achieve that greater blade displacement. Conversely, the less severe the taper of section 51, the smaller the blade displacement is obtained per angle of rotation of pusher tabs 15 with other parameters being equal. However, with a lesser taper to section 51, a lesser effort than otherwise is required by the user in rotating pusher tabs 15 to achieve that lesser blade displacement. Different retractors having these different mechanical advantages requiring greater or lesser effort are advantageously used in different surgical scenarios. Moreover, the opening distance between blades 12 may be adjustable for various procedures. The adjustment may be predetermined based on the dimensions of the components, or it may be adjustable during a procedure by utilizing pusher tubes 41 of various lengths. In an example, a larger opening retractor device may be used by OB/GYN procedures. Examples of opening distances may include two millimeters (2 mm) to eighteen millimeters (18 mm), or more. The opening distances (see ends 110 of
In operation of the above-described embodiment, referring to all Figures collectively, the user first makes a stab incision and may insert a guide-wire to determine depth of penetration. Then, if a guide-wire is used, the user inserts the device 10 in
Then, with the blades remaining closed, the user, in one embodiment, uses longer blade 12L to maneuver around nerve roots and/or other structure(s) in his/her path (this may be done before or after removal of the guide wire), without damaging nerves or causing an unwanted result. The longer blade 12L is advantageous for this purpose because it offers a small effective tip at the end of device 10 as compared with an embodiment having same-length legs 12 (e.g., substantially equal length legs). This smaller tip permits easier maneuvering around nerve root obstructions and the like which, importantly, supports better patient outcomes. Other embodiments may include retractor devices having two or more blades. In practice, the longer blade 12L may be used to sweep an area such that the user to move aside specific anatomy (e.g., an exiting nerve root). The sweep procedure may be performed by turning the retractor. Additionally, the longer blade 12L may be used to retract or specify certain anatomy or to provide improved targeting during imaging using a radio opaque material near the distal end. An example of specifying particular anatomy, the longer blade 12L may be used to target an exiting nerve root and controllably retract/push it aside.
Next, the user installs the dilator assembly shown in
In this specification, various preferred embodiments may have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The present invention is thus not to be interpreted as being limited to particular embodiments and the specification and drawings are to be regarded in an illustrative rather than restrictive sense.
It will be appreciated that the system and methods described herein have broad applications. The foregoing embodiments were chosen and described in order to illustrate principles of the methods and apparatuses as well as some practical applications. The preceding description enables others skilled in the art to utilize methods and apparatuses in various embodiments and with various modifications as are suited to the particular use contemplated. In accordance with the provisions of the patent statutes, the principles and modes of operation of this invention have been explained and illustrated in exemplary embodiments.
It is intended that the scope of the present methods and apparatuses be defined by the following claims. However, it must be understood that this invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. It should be understood by those skilled in the art that various alternatives to the embodiments described herein may be employed in practicing the claims without departing from the spirit and scope as defined in the following claims The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. Furthermore, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.
Claims
1. A tissue retractor device for retracting tissue, said device comprising:
- a base connected to a plurality of blades distributed around said base, each of said blades being outwardly movable from the base;
- a pusher engaged to said base, said pusher movable in a longitudinal direction to move said blades to angularly displace each of said blades from a respective closed position to an open position;
- at least one biasing device engaged with the base that biases the respective ones of the blades toward a closed position, wherein said closed position is where said blades are relatively close together with respect to the open position;
- wherein each of the blades includes a respective one of a plurality of shoulders, wherein each of the shoulders has a surface extending substantially perpendicular and outward from an axis of the base when the blades are in a closed position, wherein the axis is parallel to a movement direction of the pusher;
- wherein the base includes at least one surface substantially perpendicular to the axis;
- wherein the biasing device is positioned between the surface of the base and the surface of the shoulders such that the biasing device is compressed in a direction substantially parallel to the axis when the blades are moved toward the open position from the closed position.
2. The device of claim 1, wherein the pusher threadably engages said base such that rotation of the pusher moves the pusher in said longitudinal direction.
3. The device of claim 1, wherein:
- the biasing device is at least one elastic device positioned between a portion of the blades and the base; and
- the blades compress the elastic device when the blades move toward the open position to bias the blades toward the closed position.
4. The device of claim 3,
- wherein the elastic device is a plurality of springs, wherein each of the springs is positioned between the surface of the base and a respective ones of the surfaces of the shoulders to bias the blades toward the closed position.
5. The device of claim 3, wherein:
- the elastic device comprises an O-ring circumferentially positioned around a surface of the base;
- the O-ring is positioned between the surfaces of the shoulders and the surface of the base such that movement of the blades toward the open position moves the shoulders against the O-ring to bias the blades toward the closed position.
6. The device of claim 4, further comprising:
- a plurality of apertures in the base, wherein the at least one surface of the base is a plurality of surfaces at a bottom portion of respective ones of the apertures;
- wherein each of the springs residing in a respective one of the apertures;
- wherein an axial end of each of the springs abuts a respective ones of the shoulders;
- wherein movement of the blades toward the open position compresses each of the springs between the bottom portion of each aperture and respective one of the surfaces of the shoulders to bias each of the blades toward the closed position.
7. The device of claim 6, wherein a length of each of the springs is sized such that each shoulder abuts the base before fully compressing the spring when the blades are moved toward the open position.
8. The device of claim 6, wherein a length of each of the springs is sized such that each of the springs fully compresses prior to the shoulders abutting the base when the blades are moved toward the open position.
9. A tissue retractor device for retracting tissue, said device comprising:
- a base connected to a plurality of blades distributed around said base, each of said blades being outwardly movable from the base;
- a pusher engaged to said base, said pusher movable in a longitudinal direction to move said blades to angularly displace each of said blades from a respective closed position to an open position;
- at least one biasing device engaged with the base that biases the respective ones of the blades toward a closed position, wherein said closed position is where said blades are relatively close together with respect to the open position;
- each of the blades is constructed with an elastic material and is the biasing device, wherein the material blades biases the blades toward the closed position
10-17. (canceled)
Type: Application
Filed: May 22, 2013
Publication Date: Apr 24, 2014
Inventor: Alan G. Ellman (Hewlett, NY)
Application Number: 13/900,486
International Classification: A61B 17/02 (20060101);