The foregoing and other objects, features and advantages of the invention will be apparent from the following description and apparent from the accompanying drawings, in which like reference characters refer to the same parts throughout the different views. The drawings illustrate principles of the invention and, although not to scale, show relative dimensions
The present invention provides an improved surgical device and method for retracting tissue from an incision and providing access to a surgical site in a patient. The inflatable body of the retractor allows the retractor to be inserted in a deflated or semi-inflated state and then inflated in-situ to effect retraction and provide access to the surgical site. Because the retractor is inserted in a non-inflated state, the incision used for insertion does not have to be as large as required to insert traditional retractors. The inflatable body of the retractor also allows the retractor to conform to the tissue and muscle as it retracts the tissue and muscle which causes less trauma to the patient. After the necessary surgical procedure is performed using the inflatable retractor, the retractor may be deflated and removed.
In one embodiment, shown in
In certain embodiments, the inflatable body 110 is dimensioned so that the defined cavity 120 provides a passage sized to access the spine of a patient, such as the vertebra. In some such embodiments the inflatable body 110 is dimensioned so the defined cavity 120 may provide a passage for posterior access to the spine of a patient. For example, the defined cavity 120 may have a diameter of 8-40 mm and a length of 30-200 mm. In other such embodiments, the defined cavity 120 may provide a passage for anterior access to the spine. Here, the defined passage may have a diameter of 150 mm and a length of 300 mm. The inflatable body 110 may be dimensioned to add 1-10 mm to the periphery of the defined passage. Other suitable configurations, dimensions, and applications will be apparent to one skilled in the art given the benefit of this disclosure.
To reduce adverse reactions with a patient when in use the inflatable body 110 may be formed of biocompatible material. Examples of suitable biocompatible materials include, but are not limited to, poly(ethylene terephthalate) and poly(etheretherketone). In some embodiments, a polymer or metal mesh may be embedded in the body 110 to improve puncture resistance. In certain embodiments, the outer surface 140 of the retractor 100 in contact with tissue may be formed of one material while inner surface 150 defining the cavity 120 is formed of another material. Other possible materials and combinations will be apparent to one skilled in the art given the benefit of this disclosure.
In some embodiments, the inflatable body 110 of the inflatable retractor 100 may be coated or impregnated with a therapeutic agent allowing the inflatable retractor 100 to be used for drug delivery at the surgical site. For example, pain medication, antibiotics, anti-inflammatories, and other medications may be applied to or impregnated in the inflatable body 110, or applied to the outside of the body 140 and delivered at the incision site by the inflatable body 110.
In some embodiments an illuminant can be coupled to the inflatable body 110 to provide illumination at the incision site. In one example, the illuminant may be a luminescent chemical coupled to the interior surface 150 defining the cavity. In one such embodiment, the interior surface 150 is treated with a luminescent chemical. In another such embodiment, inflatable body 110 may be formed of a luminescent material. In another example, the inflatable body 110 may be formed of a translucent material and filled with a luminescent chemical, or the body may be formed of a translucent material and have a provision to attach to a light generating source separate from the retractor.
In certain other embodiments, the inflatable body 110 of the retractor 100 may include radiopaque markers. These markers aid in the percutaneous insertion of the retractor 100 under fluoroscopy.
In some embodiments, the inflatable retractor 100 further includes a valve 160 functional to maintain an inflating pressure in the inflatable body 110. A gas, liquid, or combination of both may be introduced through valve 160 to inflate the inflatable retractor 100. Suitable inflating mediums include, but are not limited to water, saline solution, air, and the like. In certain embodiments the valve 160 may also be used to release the inflating pressure thereby deflating the inflatable body 110. In some such embodiments, the retractor 100 may be inflated and deflated multiple times allowing the inflatable retractor 100 to be re-used, or the pressure adjusted interoperatively to relieve pressure on the skin, tissue, and nerves.
The required inflation pressure depends on the use of the inflatable retractor 100 as well as the type and amount of tissue being retracted. For most applications, a pressure of 80 psi would be suitable to inflate the body 110 and provide retraction. It should be understood that the type of material the inflatable body is formed of as well as the inflation medium may also affect the inflation pressure.
In some embodiments, the inflatable body 110 may be filled with a temperature sensitive liquid or gas. In one such example, the inflatable body 110 could be filled with a hardening agent, like an epoxy, that sets-up or solidifies and makes the inflated retractor rigid. In one such example, the liquid may be a wax-like material that can be made to harden or expand at a certain temperature to rigidify or inflate the retractor 100 and then re-liquefy by changing the temperature to collapse or deflate the retractor 100. In the example of a temperature sensitive gas, the gas could expand at certain temperature, such as internal body temperature, to inflate the retractor and contract at another temperature, such as room temperature, to deflate the retractor 100. An example of this can be seen in
Returning again to
In some embodiments, the inflatable retractor 100 may further include an anchor 180 attached to the inflatable body 110 for anchoring the inflatable body to a body part within the incision. The anchor 180 may comprise any suitable device such as a screw, pin, wire, or the like for anchoring the inflatable body 110 to a body part. For example, in one embodiment, the anchor 180 comprises a resorbable anchor. Alternatively the anchor 180 may comprise an anchor formed of a bio-compatible non-resorbable material. The anchor 180 may attach directly to the bone or body part. Alternatively, an anchor that is left behind after the retractor is removed and serves a second purpose such as pedicle screws fixed to the pedicle bone and used for supporting instrumented spinal stabilization, may be used to connect an inflatable body 110 to the body part.
In some embodiments as seen in
In addition to increased puncture resistance, the curvature of the outer surface 240 of the retractor 200 formed by the multiple chambers 230, 230′ provides increased surface area traction with the tissue and muscle at the surgical site. This assists in both the retraction of the tissue and muscle by the retractor 200 as well the anchoring or fixation of the retractor 200 at the surgical site. Additionally, this increased surface area spreads the load more evenly on the tissue, reducing areas of high pressures. In some embodiments, the outer surface 240 of the retractor 200 may be textured to further increase traction. In some embodiments, the inflatable retractor 200 may also have distal protrusions for assisting in the retraction of tissue and minimizing tissue creep.
In the embodiment of the retractor depicted in
In another embodiment of an inflatable retractor 300 as shown in
The conical shape provides some additional benefits when deployed in a patient. One benefit is that the larger opening at the distal end 324 of the cavity 320 provides a larger access area at the surgical site than provided by cylindrical shaped retractor without requiring a larger incision. The flared nature of the conical shaped retractor 300 also assists in the anchoring or fixation of the retractor 300 at a surgical site because the retracted tissue and muscle is displaced in such a way that it creates a partial downward pressure on the retractor walls, rather than only a normal pressure on the walls as would be the case in a cylindrical retractor.
In another embodiment of the inflatable retractor 400 of the present invention, as shown in
While the above examples of inflatable retractors depict specific configurations (cylindrical, conical, and helical) it should be understood that the inflatable body of the inflatable retractor can assume any number of possible shapes and configurations. Indeed, the conformable nature of the inflatable body allows it to be configured and used in other applications. An example of this can be seen in
In
In many instances, a surgeon will use a finger inserted into the incision to probe and perform blunt dissection between the tissue and muscles planes of a patient. The soft conforming nature of the inflatable retractor 500 allows the retractor to be used to probe and dissect the tissue and muscle planes in place of a finger. Traditionally, once the probing and separation are performed, the surgeon must insert a dilator, retractor or similar tool into the incision in place of the finger to affect the actual retraction. The advantage of using an inflatable retractor for the probing and separation, is that once the probing and separation are completed the inflatable retractor 500 can then be used to dilate and/or retract the tissue without requiring it to be replaced with another instrument.
In another embodiment, the surgeon may place their finger inside the retractor 500 in a non-inflated state, and use his or her finger, now encased in the retractor, to probe and dissect the tissue. When the surgeon removes their finger the retractor will remain in place and can be inflated to retract the tissue without being replaced by an additional instrument.
In one embodiment, the step of preparing the incision (step 620) involves additional steps. For example, blunt finger dissection between muscle planes may be performed using the actual finger of the surgeon or the inflatable retractor 500 of
Once dilation is completed, then a guide can be inserted into the incision. The guide can be used to sweep back muscle and tissue from the surgical site to find a target for inserting the inflatable retractor. An example of suitable guide can be seen in
Referring again to
The inflatable retractor is preferably inserted into the incision in a deflated state. In some embodiments, the deflated retractor is inserted using an instrument such as a dilator, catheter, trochar, or sleeve. In the case of a dilator, the deflated retractor may be wrapped around the dilator which is inserted into the incision. When the dilator is withdrawn from the incision the retractor unwraps from the dilator and is left behind in the incision. In another embodiment, the deflated or semi-inflated retractor may be inserted along a guide-wire. In still other embodiments, the deflated or semi-inflated retractor may be inserted and positioned by using a finger of the surgeon as discussed above. Alternately, a catheter, trochar, or sleeve can be used to contain, insert, and deploy the retractor in a deflated state. In some embodiments, additional instruments, such as forceps, may be used to position and deploy the inflatable retractor in situ. In some such embodiments, the positioning of the retractor in situ is performed with the aid of radiopaque markers that are discernable when viewed on a fluoroscope.
In another embodiment, as depicted in
Once the inflatable retractor has been inserted, it can then be inflated to retract tissue at the surgical site (step 640). As discussed above, the inflatable retractor may be inflated with a liquid, gas, or combination of both.
In some embodiments a hardening agent, such as an epoxy, may be used inflate the retractor. Once the retractor is inflated the epoxy sets-up or hardens to make the retractor rigid. Alternately, a hardening agent, such as a spray epoxy, may be applied to the inner surface of the retractor inflated with gas or liquid to rigidify the retractor. An example of this can be seen in
In
Once sufficient retraction of issue is obtained, necessary surgical procedures may then be performed at the surgical site. After the procedure has been performed at the surgical site, the inflated retractor may be deflated by puncturing the inflated body with an instrument such as a scalpel or releasing the pressure valve, or changing the temperature of the internal media, or by adding a softening agent. If the retractor includes an anchor, the anchor may be disconnected. The deflated retractor may then be removed and the incision closed. As discussed above, the anchor may be made of a reabsorbable or biocompatible material such that the anchors may be left in the body of the patient.
In some embodiments, such as when the inflatable retractor is used for dilation, an access device such as a rigid port, expandable retractor, or traditional retractor may be inserted over the inflatable retractor to maintain access to a surgical site. An example of this can be seen in
Once the inflatable body 1010 is in position, the inflatable body may be inflated to perform dilation and/or retraction of tissue at the surgical site. An example of this can be seen in
Once the inflatable body 1010 is inflated and the incision and tissue dilated and retracted an access device, such as a rigid port 1050 may be inserted over the inflatable body 1010. An example of this can be seen in
After the access device 1050 is in position, the inflatable body 1010 may then be deflated and removed as discussed above. An example of this can be seen in
The apparatus and techniques of the present invention provide numerous advantages. The inflatable retractor of the present invention can be used in any approach, including lateral, posterior, and anterior. The inflatable retractor is compact in a deflated state allowing for insertion through a smaller incision and requiring little or no dilation of the incision before insertion. The flexible nature of the inflatable body prevents damage to tissue, vessels, and muscle. The ability to anchor the retractor internally alleviates the need for a bed-mounted arm to secure the retractor.
The present invention has been described relative to an illustrative embodiment and application in spinal correction surgery. It should be apparent that the present invention may be used in any number of surgical procedures. Since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are to cover all generic and specific features of the invention described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.