Patent Application
20120022575
The present invention relates generally to percutaneous surgeries and more particularly, to devices for performing percutaneous, minimally invasive spinal surgeries.
Traditional surgical procedures for pathologies located deep within the body can cause significant trauma to the intervening tissues. These open procedures often require a long incision, extensive muscle stripping, prolonged retraction of tissues, denervation and devascularization of tissue. Most of these surgeries require a recovery room time of several hours and several weeks of post-operative recovery time due to the use of general anesthesia and the destruction of tissue during the surgical procedure. In some cases, these invasive procedures lead to permanent scarring and pain that can be more severe than the pain leading to the surgical intervention.
Minimally invasive alternatives such as arthroscopic techniques reduce pain, post-operative recovery time and the destruction of healthy tissue. Orthopedic surgical patients have particularly benefited from minimally invasive surgical techniques. The site of pathology is accessed through portals rather than through a significant incision thus preserving the integrity of the intervening tissues. In some instances, these minimally invasive techniques require only local anesthesia. The avoidance of general anesthesia reduces post-operative recovery time and the risk of complications.
Minimally invasive surgical techniques are particularly desirable for spinal and neurosurgical applications because of the need for access to locations deep within the body and the danger of damage to vital intervening tissues. For example, a common open procedure for disc herniation, laminectomy followed by discectomy requires stripping or dissection of the major muscles of the back to expose the spine. In a posterior approach, tissue including spinal nerves and blood vessels around the dural sac, ligaments and muscle must be retracted to clear a channel from the skin to the disc. These procedures normally take at least one-two hours to perform under general anesthesia and require post-operative recovery periods of at least several weeks. In addition to the long recovery time, the destruction of tissue is a major disadvantage of open spinal procedures. This aspect of open procedures is even more invasive when the discectomy is accompanied by fusion of the adjacent vertebrae. Many patients are reluctant to seek surgery as a solution to pain caused by herniated discs and other spinal conditions because of the severe pain sometimes associated with the muscle dissection.
In order to reduce the post-operative recovery time and pain associated with spinal and other procedures, micro-surgical techniques have been developed. The objective of any minimally invasive procedure is to accomplish the same clinical objectives as the traditional, open surgery while minimizing soft tissue retraction. Existing sequential dilation processes consist of inserting multiple increasing diameter dilators until the correct diameter is achieved. A tubular retractor is then placed over the dilators and the dilators are then removed. The retractor is left in place with the surrounding muscle and tissue having been dilated out of the working space.
For some applications, it would be beneficial to be able to dilate an incision quickly without the use of multiple individual dilators. As such, a need exists for a device that will allow physicians to quickly dilate an incision without the use of multiple individual components.
According to one aspect a surgical dilator is disclosed that is capable of dilating an incision in a patient. The surgical dilator includes a main body having a distal end and a proximal end. A locking cap is connected with the proximal end of the main body that is operable to lock the surgical dilator in a closed state for insertion into an incision as well as to unlock the surgical dilator to an open state after being inserted into the incision. A plurality of blades having a second proximal end pivotally connected with the distal end of the main body and extend downwardly toward a second distal end. When the surgical dilator is in the closed state the blades taper downwardly and inwardly from the second proximal end toward the second distal end to form an insertion tip and when the surgical dilator is in the open state the blades are operable to laterally expand.
An expansion tube is sized to be inserted into an interior cavity defined by the main body and make contact with an interior surface of each of the blades. As the expansion tube is compressed into the interior cavity the expansion tube causes the blades to laterally expand and dilate the incision. A width of each of the blades is larger at the proximal end and tapers to a smaller width at the second distal end. In the closed state the blades form a generally uniform cone-shaped blade. A collar is positioned between the proximal end of the main body and an end of the locking cap. A plurality of locking pins is connected with a lower surface of the collar and extends downwardly through a plurality of channels formed in the main body. In the closed state a distal end of each the locking pins extend outwardly from the distal end of the main body and engage an aperture in a respective blade thereby forcing the blades into the closed state. In the open state a distal end of each the locking pins is retracted away from the blades thereby allowing the blades to pivotally move in relation to the main body.
Another aspect discloses a surgical dilator that is capable of dilating an incision in a patient. In this form, the surgical dilator includes a main body having a distal end and a proximal end. A locking cap is connected with the proximal end of the main body. A collar is positioned between the locking cap and the proximal end of the main body. A plurality of locking pins are connected with an end of the collar and positioned in a plurality of channels located in the main body. A distal end of the locking pins is operable to protrude outwardly from the channels on the distal end of the main body. A plurality of blades is movably connected with the distal end of the main body. The distal ends of the locking pins are operable to engage an aperture in the blades to force the blades into a closed state for inserting the blades into an incision.
In one form, the second distal ends of the locking pins are operable to be released from the blades so that the blades are operable to laterally expand. A plurality of springs are included that have a first portion positioned in a set of apertures located on the proximal end of the main body and a second portion in engagement with the end of the collar. The springs are operable to force the locking cap upwardly thereby causing the distal ends of the locking pins to disengage the aperture in the blades thereby releasing the blades from the closed state. A pin is positioned in a proximal portion of the main body that extrudes through a control slot in a side surface of the locking cap. As the locking cap is rotated about the main body the control slot includes a vertical slot portion that becomes aligned with the pin thereby causing the springs to force the locking cap upwardly thereby disengaging the locking pins from the aperture.
In another form, the locking cap includes a conductive area and at least a lower portion of at least one of the blades includes a second conductive area. The second conductive area is configured to transmit an electric signal to provide the surgical dilator with neural monitoring capabilities. The distal end of the main body includes a plurality of mounting arms and a proximal end of each of the blades includes an arm. The arms of the blades are oriented between the mounting arms of the main body and the arms are pivotally connected to the mounting arms with a plurality of pins. The pins are inserted into the mounting arms and into the arms of the blades through a plurality of pin channels located on a side surface of the mounting arms. The surgical dilator also includes an expansion tube that is sized to be inserted into an interior cavity formed in the main body and into contact with an interior surface of the blades. As the expansion tube is compressed downwardly the blades laterally expand when the blades are not in the closed state.
Yet a further aspect discloses a surgical dilator that is capable of dilating an incision in a patient. The surgical dilator includes a main body having a distal end and a proximal end. A plurality of blades is connected with and extend downwardly from the distal end of the main body. The surgical dilator includes means for orienting the blades in a locked state in which the blades combine to form a generally uniform blade structure having a generally cone-shaped configuration. In addition, the surgical dilator further includes means for orienting the blades in an unlocked state in which the blades can be laterally expanded.
In one representative form, the means for orienting the blades in the locked state comprises a locking cap connected with the proximal end of the main body, a collar positioned between the proximal end and the locking cap having a plurality of locking pins connected therewith that extend through a plurality of channels in the main body to engage the blades to orient the blades in the locked state. In addition, the means for orienting the blades in the unlocked state comprises a control slot on a side surface of the locking cap and a pin extending through the control slot that is located on the main body. When the pin is oriented in the control slot in a predetermined position the locking pins disengage the blades thereby allowing the blades to laterally expand. A plurality of springs is positioned between the proximal end of the main body and the collar to bias the locking pins in a position in which the blades are maintained in the unlocked state.
Related features, aspects, embodiments, objects and advantages of the present invention will be apparent from the following description.
a-10d is a perspective view of illustrative expansion tubes.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any such alterations and further modifications in the illustrated devices, and such further applications of the principles of the invention as illustrated herein are contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring collectively to
The dilator 10 includes a main body 18, a locking cap 24, and tapered blades 14. The locking cap 24 is used to lock the blades 14 in the closed state for insertion into the incision 12 and to release or unlock the blades 14 so that they can be expanded outwardly for the purpose of dilating the incision 12. Referring to
A plurality of blade mounting arms 34 extend outwardly from the distal end 26 of the main body 18. As illustrated in
Referring collectively to
As illustrated in
A distal end 70 of the main body 18 includes a plurality of spring apertures 72 that are sized and configured to receive a plurality of springs 74. When installed, the springs 74 exert an upward force on a lower surface 76 of the collar 56 thereby tending to bias the locking pins 30 in a retracted state. The locking cap 24 also includes at least one L-shaped control slot 78 on an outside surface 80 of the locking cap 24 that allows the locking cap 24 to be oriented in locked and unlocked positions. As previously set forth, in the unlocked position the blades 14 are free to expand outwardly to dilate the incision 12 and in the locked position the blades 14 are forced together in the closed state. Keeping the blades 14 locked in the closed state permits the blades 14 to be inserted without having to be concerned about the blades 14 wanting to separate as the blades 14 are inserted into the incision 12.
As set forth above, the springs 74 bias the locking cap 24 in an upward position by applying force to the lower surface 76 of the collar 56. The L-shaped control slot 78 comprises a vertical slot portion 82 and a horizontal slot portion 84. The distal end portion 68 of the main body 18 includes at least one cap pin aperture 86 that is sized to receive a locking cap pin 88 that is exposed on an outside surface 90 of the main body 18. Once the locking pins 30 are inserted into the main body 18 and the locking cap 24 is positioned over the distal end portion 68 of the main body 18, the locking cap pin 88 is inserted into the cap pin aperture 86 through the control slot 78 in the locking cap 24 thereby securing the locking cap 24 to the main body 18.
To unlock the blades 14, the locking cap 24 is rotated about the main body 18 so that the locking cap pin 88 is exposed to the vertical slot portion 82 of the control slot 78. The springs 74 then force the collar 56 and locking cap 24 upwardly thereby placing the locking pins 30 in a retracted position in which the locking pins 30 no longer force the blades 14 to be in the closed state. In particular, this causes the distal ends 50 of the locking pins 30 to be removed from the closing apertures 48 in the blades 14 thereby allowing them to pivotally move about the blade mounting pins 36. The locking cap pin 88 makes contact with a distal end 92 of the vertical slot portion 82 to stop the locking cap 24 and collar 56 from travelling upwardly on the distal end 68 of the main body 18 any further than necessary to unlock the locking pins 30. To lock the blades 14 back in a closed state, a user exerts a downward force on the locking cap 24 thereby causing the springs 74 to compress and then rotates the locking cap 24 horizontally to orient the locking cap pin 88 in the horizontal slot portion 84 of the control slot 78. Compression of the springs 74 causes the locking cap 24 to exert a downward force on the collar 56 thereby forcing the distal ends 50 of the locking pins 30 back into the closing apertures 48 of the blades 14. The orientation or alignment of the closing apertures 48 in the blades 14 forces the blades 14 to the closed state as the locking pins 30 are received in the closing apertures 48.
Referring to
Referring to
In the form illustrated in
As the expansion tubes 100 are inserted and make contact with the internally curved surfaces 96 of the blades 14, the blades 14 begin to expand laterally. As the blades 14 expand laterally, gaps 120 are formed between the respective blades 14 as illustrated in
Referring to
In one form, the surgical dilators disclosed herein are sized and configured to achieve a range of dilation from approximately 5.3 mm to 21 mm, but other ranges are envisioned. The dilation members and retaining pins disclosed herein can be manufactured from various materials such as aluminum, anodized aluminum, plastic, titanium, titanium alloys, steel, and so forth.
Although various embodiments have been described as having particular features and/or combinations of components, other embodiments are possible having a combination of any features and/or components from any of embodiments as discussed above. As used in this specification, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, the term “a member” is intended to mean a single member or a combination of members, “a material” is intended to mean one or more materials, or a combination thereof. Furthermore, the terms “proximal” and “distal” refer to the direction closer to and away from, respectively, an operator (e.g., surgeon, physician, nurse, technician, etc.) who would insert the medical implant and/or instruments into the patient. For example, the portion of a medical instrument first inserted inside the patient's body would be the distal portion, while the opposite portion of the medical device (e.g., the portion of the medical device closest to the operator) would be the proximal portion.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.
