US-12622580-B2 - System and method for image guided transoral robotic surgery using an imaging compatible oral retractor system

Abstract

A support rig for a medical instrument can hold a medical instrument that is inserted into a patient in a fixed position and orientation relative to patient, so that the position and orientation of the medical instrument is not affected by the breathing or other motion of the patient. The support rig and medical instrument can be radiolucent and non-metallic, so that an image can be taken of the patient while the medical instrument is inserted in the patent and held by the support rig. The radiolucent support rig and medical instrument can allow for imaging, including x-ray, CT, and/or MRI, to occur simultaneously during the surgery. Surgical outcomes can be improved by using imaging to provide information about a tumor and/or anatomical structures during surgery.

Inventors

• Yuan Shi
• Xiaotian Wu
• Joseph A. Paydarfar
• Ryan J. Halter

Assignees

• DARTMOUTH-HITCHCOCK CLINIC
• THE TRUSTEES OF DARTMOUTH COLLEGE

Dates

Publication Date

20260512

Application Date

20220308

Claims (11)

1. 1 . A method of manufacturing a customized radiolucent and MR compatible retractor for use in image guided trans-oral robotic surgery, the method comprising the steps of: acquiring an image of an oral cavity and airway of a patient; identifying a location of a tumor; making a 3D model representing associated anatomy; designing a customized retractor based on the 3D model and the location of the tumor, wherein designing the customized retractor comprises modifying geometry of at least one of a tongue blade or a maxillary blade to provide surgical access to the identified tumor based on its position in the 3D model of the patient's anatomy; and 3D printing the customized retractor based upon the step of designing.
2. 2 . The method as set forth in claim 1 wherein the step of 3D printing includes printing a maxillary blade supported by a body that enables one or more surgical instruments to pass therethrough and is movable relative to a tongue blade to allow a retraction operation on the patient.
3. 3 . The method as set forth in claim 2 wherein the step of 3D printing further comprises constructing the tongue blade to be movable transversely to the body.
4. 4 . The method as set forth in claim 2 wherein the maxillary blade is constructed from a Nylon material and the tongue blade is constructed by 3D printing with a carbon fiber-reinforced composite material selected for use within an MR imaging field.
5. 5 . The method as set forth in claim 4 wherein the tongue blade includes a grooved rack and that slidably engages a tongue blade base having a cam for locking and unlocking a slidable adjustment position of the tongue blade relative to the body.
6. 6 . The method as set forth in claim 5 wherein the retractor includes an arm assembly adapted to mount, at a proximal end of the retractor, to a support stand, the arm being adjustable in length of extension to thereby move the tongue blade and maxillary blade.
7. 7 . The method as set forth in claim 6 wherein the arm assembly includes, at the proximal end, a support that allows for an angle of the arm assembly to be adjusted using a worm gear.
8. 8 . The method as set forth in claim 7 wherein the tongue blade base adjustably moves along the arm assembly so as to vary a distance between the tongue blade and the maxillary blade.
9. 9 . The method as set forth in claim 8 wherein the tongue blade base includes a set screw to fix a position thereof relative to the arm assembly.
10. 10 . The method as set forth in claim 1 , further comprising, adjusting an overall length of the arm assembly by moving a telescoping portion of the arm assembly relative to a sleeve and fixing the portion with respect to the sleeve in a desired position.
11. 11 . The method as set forth in claim 1 , wherein the customized retractor design includes cut-away or relief regions aligned with the tumor site to optimize access and reduce obstruction in an image-guided robotic procedure.

Description

RELATED APPLICATION This application claims the benefit of U.S. Provisional Application Ser. No. 63/158,822, entitled SYSTEM AND METHOD FOR IMAGE GUIDED TRANSORAL ROBOTIC SURGERY USING AN IMAGING COMPATIBLE ORAL RETRACTOR SYSTEM, filed Mar. 9, 2021, the teachings of which are expressly incorporated herein by reference. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with U.S. government support under the National Cancer Institute Grant Number R21CA246158, awarded by the National Institutes of Health. The government has certain rights in this invention. FIELD OF THE INVENTION This invention relates to image guided Trans-Oral Robotic Surgery (TORS) and more particularly, to TORS using an imaging compatible oral retractor system. BACKGROUND OF THE INVENTION Head and neck cancer (oral cavity, pharynx, and larynx) represents the fifth most common cancers worldwide. Minimally invasive approaches such as trans-oral robotic surgery (TORS) have demonstrated improved outcomes for managing cancers of the pharynx and larynx with decreased morbidity when compared with traditional open surgical treatments. Because of the limited haptic feedback available during robotic surgery, surgeons are required to rely on preoperative imaging for guidance. However, the placement of necessary retractors during TORS to create the surgical working volume deforms the tumor and soft tissues, which renders the preoperative imaging inaccurate. It would be desirable for surgeons to be able to use intraoperative imaging such as CT (computed tomography) and MR (magnetic resonance) imaging during surgery. Intraoperative imaging in conjunction with image-guided surgical navigation can provide real time feedback of the deformed state and help assess the extent of tumor and location of critical structures. Currently-available metallic retractors typically used in TORS (e.g. FK and Crowe-Davis retractors) cause significant streak artifacts in CT imaging and cannot safely be used in MRI. It would be desirable to have an oral retractor system that is compatible with these imaging systems. It would be further desirable to provide a device that is customizable to the anatomical specificities of an individual patient's anatomy. SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the prior art by providing a system and method of manufacturing a customized radiolucent and MR compatible retractor for use in image guided trans-oral robotic surgery. An image of an oral cavity and airway of a patient is acquired and the location of a tumor is identified. A 3D model representing associated anatomy is made and a customized retractor is then designed based on the 3D model and the location of the tumor. The customized retractor is then 3D-printed based upon the design. Illustratively, a maxillary blade supported by a body is 3D-printed, and enables one or more surgical instruments to pass therethrough. The body/maxillary blade is movable relative to a tongue blade to allow a retraction operation on the patient. The tongue blade can be constructed to be movable transversely to the body and/or the maxillary blade can be constructed from a Nylon material and the tongue blade is constructed from a carbon fiber composite material. The tongue blade can include a grooved rack can slidably engage a tongue blade base having a cam for locking and unlocking a slidable adjustment position of the tongue blade relative to the body. The retractor can further include and arm assembly adapted to mount, at a proximal end of the retractor, to a support stand, the arm being adjustable in length of extension to thereby move the tongue blade and maxillary blade. The arm assembly can include, at the proximal end, a support that allows for an angle of the arm assembly to be adjusted using a worm gear. The tongue blade base adjustably moves along the arm assembly so as to vary a distance between the tongue blade and the maxillary blade. The tongue blade base can include a set screw, which can be constructed from a polymer or other radiolucent/MR-compatible material, to fix a position thereof relative to the arm assembly. An overall length of the arm assembly can be adjusted by moving a telescoping portion of the arm assembly relative to a sleeve and fixing the portion with respect to the sleeve in a desired position. In another illustrative embodiment, a system and method of performing image-guided trans-oral robotic surgery is provided. A radiolucent and MR compatible retractor adapted to open an oral cavity is inserted. A support stand/rig is adjusted to hold the radiolucent and MR compatible retractor in a fixed position and orientation relative to the support stand/rig. Once adjusted and fixed, trans-oral robotic surgery is performed, and/or imaging is performed using x-rays, CT, or MRI during the trans-oral robotic surgery so that the surgery can be informed by the imaging. In another illustrative embodiment, a syste