Surgical tool-positioning devices and related methods

Abstract

The disclosure describes assemblies for use during image-guided procedures and can include turret arms and/or longitudinally extending and laterally extending cooperating devices for holding surgical tools such as trajectory guides.

That which is claimed is: 
     
         1 . A surgical assembly, comprising:
 a head fixation frame comprising an upwardly extending right member and an upwardly extending left member, the right member and the left member configured to reside on opposing sides of a head of a patient, wherein the right member and the left member each comprise at least one head fixation member extending laterally inward toward each other;   an arcuate support member coupled to the head fixation frame, wherein, in use, the arcuate support member resides adjacent to but longitudinally spaced apart from the right and left members of the head fixation frame and the patient, wherein the arcuate support member comprises inner and outer arcuate perimeters and a planar upper surface;   at least one turret arm attached to the arcuate support member, wherein the at least one turret arm comprises opposing first and second end portions with an arcuate segment therebetween, and wherein the at least one turret arm is configured to place the first end portion and the arcuate segment above the arcuate support member, wherein the at least one turret arm is lockable to the arcuate support member at different lateral positions between the right and left members of the head fixation frame; and   a trajectory guide assembly attached to the arcuate segment of the at least one turret arm, wherein the trajectory guide assembly is positionally adjustable along a length of the arcuate segment.   
     
     
         2 . The surgical assembly of  claim 1 , wherein the trajectory guide assembly comprises a turret attachment arm defining an elongate slot, wherein the turret attachment arm extends off an outer perimeter of a semi-circular base portion of the trajectory guide assembly, wherein the turret attachment arm is perpendicular to the semi-circular base portion of the trajectory guide assembly, wherein the semi-circular base portion surrounds an open center space, wherein the semi-circular base portion comprises a plurality of spaced apart fiducial markers, and wherein a mounting member extends through the elongate slot to attach the trajectory guide assembly to the arcuate segment of the at least one turret arm thereby allowing the trajectory guide assembly to be positionally adjustable relative to the patient in X, Y and Z directions. 
     
     
         3 . The surgical assembly of  claim 1 , wherein at least the arcuate segment of the at least one turret arm has a rectangular cross-sectional shape. 
     
     
         4 . The surgical assembly of  claim 1 , wherein the trajectory guide assembly comprises a base comprising a semi-circular perimeter surrounding an open center portion with first and second neighboring base perimeter segments that are arcuate and that are spaced apart from each other, and wherein the trajectory guide assembly is slidably attachable to the at least one turret arm so that the trajectory guide assembly is slidably positionable at different positions over a length of the arcuate segment of the at least one the turret arm. 
     
     
         5 . The surgical assembly of  claim 1 , wherein the arcuate segment of the at least one turret arm has a radius of curvature, measured from a centerline of a center aligned with a deep brain region of a patient, behind and above an ear and below an eye socket, that is between about 100 mm and 150 mm. 
     
     
         6 . The surgical assembly of  claim 1 , further comprising a mount member attached to the arcuate segment of the at least one turret arm and to the trajectory guide assembly, wherein the mount member is slidably positionable about the arcuate segment and securely attaches the trajectory guide assembly at a desired location on the arcuate segment of the at least one turret arm, wherein the mount member comprises an open center channel that slidably receives one turret arm of the at least one turret arm, and wherein the mount member has a cross-sectional perimeter shape that has two long sides and two shorter sides. 
     
     
         7 . The surgical assembly of  claim 4 , wherein the open center portion is configured to overlie a target intrabody entry point of a skull of the patient. 
     
     
         8 . The surgical assembly of  claim 1 , wherein the second end portion of the at least one turret arm comprises a recess sized and configured to receive an upper surface of the arcuate support member. 
     
     
         9 . The surgical assembly of  claim 1 , wherein an inner perimeter of a base of the trajectory guide assembly is semi-circular and has a circumferentially extending gap space having an angular extent that is in a range of about 60 degrees to 145 degrees that positions neighboring segments of the base apart from each other, wherein the neighboring segments each comprise an upwardly extending arcuate arm, and wherein the base holds a plurality of circumferentially spaced apart fiducial markers. 
     
     
         10 . The surgical assembly of  claim 1 , wherein the trajectory guide assembly is configured to extend entirely off only a single side of the arcuate segment of one turret arm of the at least one turret arm and over a target intrabody site of the head of the patient and entirely under the arcuate segment of the one turret arm. 
     
     
         11 . The surgical assembly of  claim 1 , further comprising left and right transverse members coupled to the head fixation frame and to a scanner bed. 
     
     
         12 . The surgical assembly of  claim 11 , wherein the left and right transverse members are attached to longitudinally extending rails of the scanner bed. 
     
     
         13 . The surgical assembly of  claim 1 , wherein the surgical assembly is configured to be coupled to a scanner bed of an MRI scanner and is movably positionable in concert with the scanner bed within a bore of a magnet of an MRI scanner. 
     
     
         14 . The surgical assembly of  claim 1 , wherein the at least one turret arm has a length that is in a range of about 9-12 inches. 
     
     
         15 . The surgical assembly of  claim 1 , wherein the surgical assembly is MRI compatible. 
     
     
         16 . A method of preparing for an image-guided surgery, comprising:
 providing a head fixation assembly;   coupling the head fixation assembly to a scanner bed;   attaching a laterally extending support member to the head fixation assembly, wherein the support member is arcuate, wherein the laterally extending support extends laterally a distance sufficient to surround a head of a patient;   attaching a lower end portion of a turret arm directly to the laterally extending support member, wherein the at least one turret arm has a body with an arcuate segment merging into the lower end portion, and wherein the arcuate segment extends above the laterally extending support member;   adjusting a location of the turret arm relative to the laterally extending support member to a desired position relative to the head of the patient;   attaching a trajectory guide assembly to the arcuate segment of the turret arm; and   performing an MRI-guided surgical neurological procedure to treat the patient while the trajectory guide assembly is attached to the turret arm and the head fixation assembly is coupled to the patient and with the patient on the scanner bed in a bore of a magnet of an MRI scanner.   
     
     
         17 . The method of  claim 16 , wherein the trajectory guide assembly comprises an open cylindrical channel and a trajectory guide base, wherein the trajectory guide base comprises an attachment arm with an elongate slot, the attachment arm extending perpendicular to a planar semi-circular bottom of the trajectory guide base, wherein the semi-circular bottom resides under the attachment arm with the elongate slot and projects outwardly away from the attachment arm and the turret arm toward the patient with the attachment arm residing closer to the turret arm than the planar bottom, and wherein the planar semi-circular bottom comprises an inner perimeter extending about an open center portion with first and second neighboring base perimeter segments that are circumferentially spaced apart from each other a distance of between  20 - 180  degrees, and wherein each of the first and second neighboring perimeter segments comprise an upwardly projecting arcuate arm. 
     
     
         18 . The method of  claim 16 , wherein, during the MRI-guided surgical procedure, the trajectory guide assembly is not attached to a head of the patient. 
     
     
         19 . The method of  claim 16 , wherein the MRI-guided surgical neurological procedure comprises delivering a therapeutic agent to a target brain location of the patient. 
     
     
         20 . The method of  claim 16 , wherein the MRI-guided surgical neurological procedure comprises ablating target tissue of a brain of the patient.