WO2008048517A2

WO2008048517A2 - Intraoperative tracking and positioning of transnasally inserted devices

Info

Publication number: WO2008048517A2
Application number: PCT/US2007/021922
Authority: WO
Inventors: Joshua Makower
Original assignee: Acclarent, Inc.
Priority date: 2006-10-13
Filing date: 2007-10-11
Publication date: 2008-04-24
Also published as: WO2008048517A3

Abstract

Methods and systems for performing procedures within the ear, nose throat or paranasal sinus and/or for determining the current position of a trans-nasally inserted device within the body of a human or animal subject. A pre-operative tomographic image is obtained prior to the procedure and displayed on a display. A working device is inserted through the subjects nostril and an intra-operative tomographic imaging device is then used to obtain one or more intra-operative tomographic images (e.g., showing the position/effects of the working device within the body, changes to anatomical structures of interest, other desired structures, etc.). A processor receives data from the intra-operative tomographic imaging device and either i) replaces the pre-operative tomographic image with the intra-operative tomographic image or ii) integrates the intra-operative tomographic image into the pre-operative tomographic image, thereby updating the tomographic image viewed on the display.

Description

INTRAOPERATIVE TRACKING AND POSITIONING OF TRANSNASALLY INSERTED DEVICES

RELATED APPLICATION

This patent application claims priority to United States Provisional Patent Application No. 60/851 ,573 filed October 13, 2006, the entire disclosures of which is expressly incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to the fields of engineering and medicine and more particularly to devices and methods for treated disorders of the ear, nose, throat or paranasal sinuses.

BACKGROUND

The following United States Published Patent Applications listed in Table A describe imaging devices and methods that are useable in, or otherwise relate to, the present invention. The entire disclosure of each United States Published Patent Application listed in Table A is expressly incorporated herein by reference:

TABLE A

Additionally, listed in Table B below are PCT International Patent Publications that describe imaging devices and methods that are useable in, or otherwise relate to, the present invention. These PCT International Patent Publications form an integral part of this provisional patent application and are also expressly incorporated herein by reference. All or portions of these PCT International Patent Publications may be duplicative of information contained in one or more of the above-incorporated United States Published Patent Applications.

TABLE B

The Use of Image Guidance In Ear, Nose and Throat Procedures

Image guided surgery (IGS) procedures (sometimes referred to as "computer assisted surgery") is sometimes used in certain ear, nose and throat (ENT) surgeries, including sinus surgeries. In a typical IGS procedure, a pre-operative digital tomographic scan (e.g., a CT or MRI scan) of the operative field (e.g., the nasal cavities and paranasal sinuses) is obtained prior to surgery and image data from that scan is stored in a specially programmed computer which creates a three-dimensional digital map of the surgical field. Later, the surgery is performed using one or more instruments that have "sensors" mounted therein or thereon which send data to the computer indicating the position of each surgical instrument. The computer correlates the data received from the instrument-mounted sensors with the digital map that was created from the preoperative tomographic scan. One or more image(s) is/are then displayed on a monitor showing the images from the original tomographic scan along with an indicator (e.g., cross hairs or an illuminated dot) showing the real time position of the surgical instrument. In this manner, the surgeon is able to view the precise position of each sensor- equipped instrument relative to the surrounding anatomical structures shown on the tomographic scan.

A typical IGS surgery system of the prior art includes a) a computer work station, b) a video monitor, c) one or more surgical instruments having sensors mounted therein or thereon, d) a localizer and e) a sensor tracking system. The sensor(s) mounted on the surgical instruments and the corresponding tracking system may be optical, electromagnetic or electromechanical. The localizer functions to localize or "register" the preoperative tomographic image data with the real time physical positioning of the patient's body during surgery. The sensor tracking system serves to track the position of each sensor equipped surgical instrument during the surgery and to communicate such information to the computer workstation.

In IGS systems that employ optical sensors/tracking systems, optical "sensors" (e.g., infrared reflecting spheres or infrared light emitting diodes (i.e., LEDs)) are placed on the surgical instruments and on a localizer frame worn by the patient. A camera is positioned such that it receives light emitted or reflected from the sensors. One example of an optical IGS system that is useable in ENT and sinus surgery is the LandmarX Evolution^® ENT Il Image Guidance System available from Medtronic Xomed Surgical Products, Inc., Jacksonville, Florida.

In IGS systems that employ electromagnetic sensors/tracking systems, radiofrequency electromagnetic sensors (e.g., electromagnetic coils which emit or detect energy) are positioned in or on the instrument(s) and the IGS system detects the position of each such electromagnetic coil. Examples of commercially available electromagnetic IGS systems that have been used in ENT and sinus surgery include the ENTrak Plus™, InstaTrak ENT™ and InstaTrak 3500 Plus systems available from GE Medical Systems, Salt Lake City, Utah. Other examples of electromagnetic image guidance systems that may be modified for use in accordance with the present invention include but are not limited to those available from Surgical Navigation Technologies, Inc., Louiville, Colorado, Biosense-Webster, Inc., Diamond Bar, California and Calypso Medical Technologies, Inc., Seattle, Washington.

Developments in Tomographic Scanner Technology

Traditionally, CT scanners have been large, non-portable, stationary installations placed at locations that are some distance from where surgery is actually performed on a subject. Thus, in the prior art IGS systems, the preoperative digital tomographic scan data has typically been obtained at another location (e.g., an imaging center or hospital radiology department) days or weeks prior to surgery and then stored into the IGS computer for use during the surgical procedure. Recently, however, small, portable tomographic scanners and techniques have been developed to allow CT scans to be obtained intra-operatively (i.e., immediately prior to or at one or more times during the performance of the surgery). Examples of such intra-operative CT scanners and related methods/software are described in the above- incorporated United States Published Patent Applications listed in Table A and the above-incorporated PCT International Patent Publications listed in Table B. One such portable CT scanning system is designed for use in ENT procedures and commercially available as the xCAT™ Portable CT System (Xoran Technologies, Inc., Ann Arbor, Michigan). This xCAT™ system is a personal computer (PC) based system that incorporates a workstation equipped with an integrated monitor, keyboard and mouse, as well as an articulating arm and a platform with a wide handle. CT scans may acquired and displayed on the integrated monitor in less than 3 minutes. CT scan images can be exported via portable media (like a CD or USB flash drive) or stored on the built-in computer. Images can also be accessed remotely using a secure web-based system (the MiniPACS™ system, Xoran Technologies, Inc., Ann Arbor, Michigan). This system creates CT images with isotropic spatial resolution of 0.4 mm and has a customized field of view which is optimized for scanning the sinuses, temporal bones and the skull base with a relatively low effective radiation dose to the patient (e.g., purportedly as low as 0.25 mSv).

Relatively new catheter-based procedures and tools have been and are being developed by applicant at Acclarent, Inc. of Menlo Park, California for the performance of less traumatic sinus, paranasal and endonasal surgeries. These new procedures and tools include, but are not limited to balloon dilation of the ostia of paranasal sinuses. In such procedure, a guide catheter (e.g., Relieva™ Guide Catheter, Acclarent, Inc., Menlo Park, California) having a substantially fixed shape is inserted through the nose and advanced to a position where the distal end of the guide catheter is adjacent to the ostium of a paranasal sinus. A guidewire is then advanced through the guide catheter and into the paranasal sinus. Thereafter, a balloon catheter (e.g., Relieva™ Balloon Catheter, Acclarent, Inc., Menlo Park, California) is advanced over the guidewire and is used to dilate the ostium of the paranasal sinus, thereby improving drainage from and/or ventilation of that paranasal sinus. Examples of such devices and procedures for balloon dilation of a paranasal sinus ostium are described in United States Patent Application Nos. 10/829,917 entitled "Devices, Systems and Methods for Diagnosing and Treating Sinusitis and Other Disorders of the Ears, Nose and/or Throat,; 10/944,270 entitled "Apparatus and Methods for Dilating and Modifying Ostia of Paranasal Sinuses and Other Intranasal or Paranasal Structures," 11/116,118 entitled "Methods and Devices for Performing Procedures Within the Ear, Nose, Throat and Paranasal Sinuses," 11/150,847 entitled "Devices, Systems And Methods Useable For Treating Sinusitus" and 11/234,395 entitled Devices and Methods for Delivering Therapeutic Substances for the Treatment of Sinusitis and Other Disorders, the entire disclosure of each such patent application being expressly incorporated herein by reference. These procedures are performable using various types of guidance including but not limited to C-arm fluoroscopy, transnasal endoscopy, optical image guidance and/or electromagnetic image guidance. Also, new procedures are being developed for the medical and surgical treatment of ethmoid sinus disease as well as the use of implantable substance delivery devices for the treatment of ear nose and throat disorders including sinusitis, otitis media and other conditions. Examples of these other new procedures are described in co-pending United States Patent Applications No. 11/234,395 entitled "Devices and Methods for Delivering Therapeutic Substances for the Treatment of Sinusitis and Other Disorders" filed on September 23, 2005; 10/829,917 entitled Devices, Systems and Methods for Diagnosing and Treating Sinusitis and Other Disorders of the Ears, Nose and/or Throat filed on April 21 , 2004; 10/912,578 entitled Implantable Device and Methods for Delivering Drugs and Other Substances to Treat Sinusitis and Other Disorders filed on August 4, 2004; 11/037,548 entitled Devices, Systems and Methods for Treating Disorders of the Ear, Nose and Throat, filed on January 18, 2005 and 11/544,009 entitled "Implantable Devices And Methods For Treating Sinusitis And Other Disorders" filed on October 4, 2006, each of which is expressly incorporated herein by reference.

The availability of CT scanning devices such as the xCAT™ Portable CT System presents the potential for real time, continuous or intermittent intra-operative monitoring of the location of catheters, guidewires or other instruments during a ENT procedures (e.g., balloon dilation of the ostia of paranasal sinuses, performance of ethmoidotomy procedures, implantation is substance delivery devices and various other ENT procedures) where one or more devices are inserted trans-nasally (i.e., through a nostril), without the need for expensive and complex IGS systems of the prior art.

SUMMARY OF THE INVENTION

The present invention provides methods and systems for performing procedures within the ear, nose throat or paranasal sinus and/or for determining the current position of a trans-nasally inserted device within the body of a human or animal subject. A pre-operative tomographic image is obtained prior to the procedure and displayed on a display. A working device is inserted through the subjects nostril and an intra-operative tomographic imaging device is then used to obtain one or more intra-operative tomographic images (e.g., showing the position/effects of the working device within the body, changes to anatomical structures of interest, other desired structures, etc.). A processor receives data from the intra-operative tomographic imaging device and either i) replaces the pre-operative tomographic image with the intra-operative tomographic image or ii) integrates the intra-operative tomographic image into the pre-operative tomographic image, thereby updating the tomographic image viewed on the display.

In accordance with the invention, there are provided methods for determining the current position of a trans-nasally inserted device within the body of a human or animal subject. One embodiment of such a method generally comprises the steps of (A) performing a pre-operative or initial intra- operative tomographic scan that includes an area where a surgical or interventional procedure is to be performed, (B) inserting the device through one of the subject's nostrils, (C) performing at least one intra-operative scan of an area of interest that includes a location where the device currently resides within the subject's body and (D)using the image data from said at least one intra-operative scan to update at least a portion of preoperative or initial intra-operative scan to provide an updated scan that includes a showing of the location of the device.

Further in accordance with the invention, there are provided systems for performing diagnostic or therapeutic procedures within the ear, nose, throat or paranasal sinus of a human or animal subject. One embodiment of such a system generally comprises (A) a working device (e.g., a catheter, guidewire, scope, guide catheter, dilator, substance delivery device or any other apparatus or instrument) that is insertable through a nostril of the subject and useable to perform, or facilitate the performance of, at least a portion of the procedure, (B) a first data set comprising a pre-operative tomographic image of an area of interest, (C) a display which displays the preoperative tomographic image of the area of interest, (D) an intra-operative tomographic imaging device that is useable during performance of the procedure to generate a second data set comprising an intra-operative tomographic image of or within the area of interest and (E) a processor that receives the second data set and either i) replaces the first data set with the data set or ii) integrates the second data set with the first data set, thereby updating the tomographic image viewed on the display to include the intraoperative tomographic image.

Still further aspects, details, embodiments and objects of the invention will be understood by those of skill in the art upon reading of the detailed description and examples set forth herebelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a top end view of an intra-operative tomographic imaging device being used to obtain an intra-operative tomographic image during performance of a trans-nasal procedure on a human subject in accordance with the present invention.

Figure 2 is a perspective view of an intra-operative tomographic imaging device being used to obtain an intra-operative tomographic image during performance of a trans-nasal procedure on a human subject in accordance with the present invention.

DETAILED DESCRIPTION

The following detailed description, the accompanying drawings are intended to describe some, but not necessarily all, examples or embodiments of the invention. The contents of this detailed description do not limit the scope of the invention in any way.

The present invention provides methods and systems wherein the position of a trans-nasally inserted device is determined one or more times after its insertion using an intra-operative scanning system such as the xCAT™ Portable CT System available commercially from Xoran Technologies, Inc., Ann Arbor, Michigan and/or other scanning systems described in the various United States and PCT international patent applications listed in the above-set-forth Tables A and B above. Figures 1 and 2 show schematic diagrams of one embodiment of an intra-operative scanning system 10 such as the xCAT™ Portable CT System available commercially from Xoran Technologies, Inc., Ann Arbor, Michigan and/or other scanning systems described in the various United States and PCT international patent applications listed in the above-set-forth Tables A and B above. In this example, the intra-operative scanning system 10 comprises a rotating x-ray scanner 12, a display 14 and a computer 16. In one mode of use, the subject's head is immobilized using an immobilization apparatus 18 and/or a strap-type restraint such as tape 20 and or other suitable means. The scanning system 10 is then used to obtain a preoperative scan of a region that includes the portion of the subject's head where the intended operative field is located (e.g., the anterior portion of the head including the nose, hard palate, nasal cavity, paranasal sinuses, orbits and skull base). Images from this pre-operative scan are stored in the computer 16 and displayed on the system's display 14.

Thereafter, while the subject's head remains immobilized in the same position as it was in during the pre-operative scan, one or more working device(s) 34, 36, 38 is/are inserted trans-nasally. In the example shown, a tubular guide catheter 34 has been initially inserted and a guidewire 38 has then been advanced through the guide catheter 34. Thereafter, a working catheter 36 was advanced over the guidewire 38 and through the guide catheter 34, resulting in the system arrangement shown in Figure 2. During or after insertion and or use of any or all of the working devices 34, 36, 38, the scanning system 10 is used to obtain a first intra-operative scan that shows the position of one or more of the working device(s) 34, 36, 38 within the subject's body. As described in more detail below, the system's computer 16 then either a) replaces the pre-operative scan data with the first intra- operative scan or b) integrates data obtained from the first intra-operative scan with data from the pre-operative scan to create updated scan images that show the position of the working device(s) 34, 36, 38 within the subject's body. This process may then be continued (i.e., a continuous intra-operative scan) or repeated (i.e., a second, third, fourth, etc. intra-operative scans performed at spaced apart time intervals) to provide for continuous or periodic tracking of the location of the working device(s) 34, 36, 38 within the subject's body. In some instances, the intra-operative scan(s) may also update the preoperative scan data and/or data obtained from earlier intra-operative scans to show changes in the subject's anatomy that have occurred during or as a result of the procedure. For example, if one or more of the trans-nasally inserted working device(s) 34, 36, 38 is/are used to dilate the ostium of a paranasal sinus, an intra-operative scan may be obtained before the dilation is performed to confirm that the device being used to perform the dilation is appropriately positioned within the paranasal sinus ostium. Alternatively or additionally, an intra-operative scan may be obtained after such dilation has been performed to determine or confirm the change in diameter or shape of the sinus ostium that has resulted from the dilation procedure. In this manner, the operator may confirm that the intended dilation of the sinus ostium has been achieved. If an intra-operative scan indicates that the initial attempt to dilate the sinus ostum has not resulted in the desired amount of dilation of the ostium, the dilation step may be repeated using the same or a different (e.g., larger sized) dilation device and a subsequent intra-operative scan may then be obtained to determine in such repeat dilation has achieved the desired result.

Acquisition of ore-operative scan

As described above, the intra-operative scanner may be used to obtain the pre-operative scan in the operating room after the subject's head has been immobilized. However, in some cases, alternative procedures may be used to obtain the pre-operative scan. For example, the pre-operative scan may have been previously created using a different CT scanner (i.e., days prior to surgery) and data from the pre-operative scan may have been saved into the computer 16 of the intra-operative CT scanning system 10. In such cases, the previously-obtained pre-operative CT scan may have been performed using locators as described in PCT International Application PCT/US2004/032595 so that the position and orientation of the subject's head relative to the preoperative scan is known. Alternatively, the scanner that is used to obtain the pre-operative scan may have registered the positions of the locators on the subject's body relative to the pre-operative scan (CT or MRI) based upon the appearance of the locators in the pre-operative images as is known in the art. As another alternative, in cases where suitable, generic data (i.e. tomographic scan data not specifically obtained from the present subject) may be used in place of an actual preoperative scan of the subject.

In some cases, the pre-operative scan data may be used merely for background information and calculations required in creating a new image and may have lesser importance than each updating intra-operative scan. In such cases, the pre-operative scan may use a lower radiation dosage and/or lower resolution than would otherwise be used, thereby providing safety and cost benefits.

Acquisition and processinp of the intra-operative scan(s)

For intra-operative scans, the scanning system 10 may scan all or only part of the area included in the pre-operative scan (i.e., each intra-operative scan may update just one current area of interest rather than replacing the entire pre-operative scan). In some instances, a continuous intra-operative scan may be obtained using a scanner that is mounted on apparatus (e.g., a "gantry") that translates or moves some distance along the axis of rotation as described in PCT International patent Application No. PCT/US2004/025625. In other instances, one or more discrete intra-operative scan(s) of selected or defined area of interest may be obtained at different time points.

The system's computer 16 uses the new information obtained from^' each intra-operative scan to create and display an updated intra-operative 3D image. For example, the preoperative scan may include a relatively large area that incorporates the intended surgical field as well as surrounding anatomy of potential interest (e.g., the anterior portion of the head including the nose, hard palate, nasal cavity, paranasal sinuses, orbits and skull base). Thereafter, each intra-operative scan may include only a particular area of interest (e.g., only the area where a particular part of the device such as its distal tip is currently located) and may thus cover less area than the entire preoperative scan. In this manner, a smaller area covered by each intra- operative scan will result in less radiation exposure and will take less time than re-scanning the entire area covered by the full pre-operative scan. The surgeon can select and define the area of interest to be included in each intra- operative scan on the system's display using a computer mouse or other input device such as an "area-of-interest indicator instrument" as described certain of the United States and PCT international patent applications listed in the above-set-forth Tables A and B above.

It will be appreciated that the intra-operative scanning system 10 may be used independently as described above or, in some cases, may be used in conjunction with a separate IGS system. In cases where a separate IGS system is concurrently being used to track the position of the working device(s) 34, 36, 38, the computer 16 may determine the area of interest for each intra-operative scan based upon the previous locations of the working device(s) 34, 36, 38 as determined by the IGS system. Alternatively, the computer 16 may be programmed to display a proposed area of interest on the display 14 (or on a separate display) before an intra-operative scan is preformed and the surgeon may either accept the proposed area of interest for the next intra-operative scan or may use the mouse or other input device to modify and approve the area of interest to be scanned before proceeding with the next intra-operative scan.

In some cases, the preoperative and/or updated intra-operative scans may be used in conjunction with intra-operative fluoroscopy using a fluoroscopy system that includes a radiation source and a detector. The position and orientation of the source and detector may be repeatedly registered relative to the pre-operative and intra-operative images and the fluoroscopic image may be used to update the displayed scan images. The intra-operative fluoroscopy image created from the scan may focus on areas of interest to provide the surgeon with data sufficient for guiding the surgery. Tools (e.g., guidewires, dilatation catheters, sinus guides, sinus needles, drug eluting reservoirs, flexible endoscopes, debriders, shavers, lavage devices, suction devices, seekers, and back-biters) with radiopaque markers can be detected by the fluoroscope to identify the position of the tool. The surgeon may display 2D images or rotate and position the 3D scan images on the display 14 and select or change a desired area of interest to be scanned by the fluoroscope. Also, the surgeon may select and define a particular area of interest on the display 14 using an input device such as a mouse, or by using the interest indicator instrument mentioned above. The fluoroscope may be moved by motors controlled by the computer 16 to the correct position and orientation to scan the area of interest. Alternatively, the surgeon can manually move the fluoroscope while watching the fluoroscopy image superimposed on the 3D CT image in the current position and orientation on the display 14 until the fluoroscope has scanned the desired area of interest. Tools (e.g., guidewires, dilatation catheters, sinus guides, sinus needles, drug eluting reservoirs, flexible endoscopes, debriders, shavers, lavage devices, suction devices, seekers, and back-biters) with radiopaque markers can be detected by the fluoroscope to identify the position of the tool. Alternatively, the intra-operative scanning system 10 may be used to perform the fluoroscopy as well, by using its x-ray source as the fluoroscopy source and a detector to continuously receive x-rays from the x-ray source and the computer 16 may then generate a continuously updated 2D or 3D image on the display 14 in the manner described above.

In some cases, the preoperative and/or intra-operative scans may be used in conjunction with intra-operative fluoroscopy using a fluoroscopy system that includes at least two radiation sources and at least two corresponding detectors, preferably the axes between the sources and corresponding detectors are at different angles. The position and orientation of the sources and detectors may be repeatedly registered relative to the preoperative and intra-operative images and the fluoroscopic image may be used to update the displayed scan images. The intra-operative fluoroscopy image created from the scan may focus on areas of interest to provide the surgeon with data sufficient for guiding the surgery. Tools (e.g., guidewires, dilatation catheters, sinus guides, sinus needles, drug eluting reservoirs, flexible endoscopes, debriders, shavers, lavage devices, suction devices, seekers, and back-biters) with radiopaque markers can be detected by the at least two radiation detectors to identify the position of the tool in a 3D space. The surgeon may display 2D scan images or rotate and position the 3D scan images on the display 14 and select or change a desired area of interest to be scanned by the fluoroscope. Also, the surgeon may select and define a particular area of interest on the display 14 using an input device such as a mouse, or by using the interest indicator instrument mentioned above. The fluoroscope may be moved by motors controlled by the computer 14 to the correct position and orientation to scan the area of interest. Alternatively, the surgeon can manually move the fluoroscope while watching the fluoroscopy image superimposed on the 3D CT image in the current position and orientation on the display 14 until the fluoroscope has scanned the desired area of interest. Tools as described above with radiopaque markers can be detected by the rotating fluoroscope to identify the position of the tool in a 3D space. Alternatively, the intra-operative scanning system 10 may be used to perform the fluoroscopy as well, by using its x-ray source as the fluoroscopy source and detector to continuously receive x-rays from the x-ray source and the computer 16 can then generate a continuously updated 2D or 3D image on the display 14 in the manner described above.

Examples of Applications to Specific Trans-Nasal Procedures

The system and method of the present invention may be used in the performance of a wide variety of procedures where devices are inserted trans- nasally and positioned within the ear, nose, throat or paranasal sinuses. The following are but a few non-limiting examples of such application of this invention.

For example, the present invention includes a procedure to dilate an ostium of a paranasal sinus. In this example, the subject's head is immobilized and a pre-operative scan is performed as described above. Thereafter, a guide catheter 34 having a substantially fixed shape (e.g., Relieva™ Guide Catheter, Acclarent, Inc., Menlo Park, California) is inserted through the subject's nostril and advanced to a position where its distal end is positioned within or adjacent to the ostium to be dilated. A radiopaque marker (e.g., a metallic band) may be provided on the distal tip of this guide catheter. One or more intra-operative scans may be performed to image the distal end of the guide catheter (e.g., its radiopaque marker) within the subject's body and the data from such intra-operative scan(s) will be used to update the preoperative scan shown on the display 14, thereby showing the current position of the distal end of the guide catheter 34 relative to the target ostium and other surrounding anatomy. After an intra-operative scan confirmed that the distal end of the guide catheter 34 has been navigated to the intended position within or adjacent to the sinus ostium, a guidewire 38 is advanced through the guide catheter 34, through the ostium and into the paranasal sinus. One or more intra-operative scans may again be performed during or after such advancement of the guidewire to determine to current position of the guidewire within the subject's body. After an intra-operative scan has confirmed that the guidewire 38 is in its desired position (e.g., coiled within the paranasal sinus), a working device such as a dilation catheter 36 (e.g., Relieva™ Balloon Catheter, Acclarent, Inc., Menlo Park, California) is advanced over the guidewire 38 and through the guide catheter 34 to a position where its dilator (e.g., a balloon) is located within the ostium of the sinus (while still in a deflated state). Proximal and distal radiopaque dilator markers may be provided on the balloon catheter to mark the proximal and distal ends of the dilator's working length. Also, in at least some embodiments, a distal tip radiopaque marker may be provided on the distal tip of the dilation catheter. One or more intra-operative scans may be performed during and/or after advancement of a working device such as dilation catheter 36 to ascertain the position of certain portion(s) of the dilation catheter (e.g., the locations of the proximal and distal markers and/or the distal end marker) relative to the sinus ostium and other adjacent anatomy. After intra-operative scan(s) has/have confirmed that a) the dilator has been fully advanced out of the guide catheter so as to be capable of expanding and b) the dilator is properly positioned within the intended sinus ostium, the dilator is expanded (e.g., the balloon is inflated) one or more times to dilate the sinus ostium. Thereafter, one or more intra-operative scans may again be performed to confirm that the ostium has been dilated sufficiently (e.g., to an intended diameter or size).

By way of another example, the present invention includes a method for performing a needle ethmoidotomy. In such procedure, subject's head is immobilized and a pre-operative scan is performed as described above. Thereafter, a penetrator such as a needle is advanced through the ethmoid bulla and into one or more ethmoid air cells. Examples of needles and associated apparatus that may be used to perform this procedure are described in United States Patent Application 11/544,009 filed on October 4, 2006 and United States Provisional Patent Application No. 60/922,730 filed April 9, 2007, the entire disclosures of which are expressly incorporated herein by reference. One or more intra-operative scans may be performed during and/or after advancement of the sinus needle to determine the needle's current position within the subject's body and to avoid advancing the needle through the adjacent skull base or otherwise damaging adjacent anatomical structures.

As yet another example, the present invention includes a method for trans-nasal implantation of a substance delivery device which delivers a diagnostic or therapeutic substance (e.g., a drug) over a desired time period. In such procedure, the subject's head is immobilized and a pre-operative scan is performed as described above. Thereafter, the implanted substance delivery device is advanced through the nostril and implanted at a desired location (e.g., within a diseased paranasal sinus). In some instances, the implantable substance delivery device may comprise a reservoir that is filled with the desired substance after the device has been properly positioned within the intended paranasal sinus of other intended implantation site (e.g., within a Eustachian tube, naso-lacrimal duct, etc.). One or more intra- operative scans may be performed during and/or after advancement, positioning and/or filling of the implantable substance delivery device to ascertain its current position within the subject's body and/or to confirm that it is properly positioned at the intended implantation site.

It is to be appreciated that the invention has been described hereabove with reference to certain examples or embodiments of the invention but that various additions, deletions, alterations and modifications may be made to those examples and embodiments without departing from the intended spirit and scope of the invention. For example, any element or attribute of one embodiment or example may be incorporated into or used with another embodiment or example, unless otherwise specified of if to do so would render the embodiment or example unsuitable for its intended use. Also, where the steps of a method or process have been described or listed in a particular order, the order of such steps may be changed unless otherwise specified or unless doing so would render the method or process unworkable for its intended purpose. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A method for determining the current position of a trans-nasally inserted device within the body of a human or animal subject, said method comprising the steps of:

(A) performing a pre-operative or initial intra-operative tomographic scan that includes an area where a surgical or interventional procedure is to be performed;

(B) inserting the device through one of the subject's nostrils;

(C) performing at least one intra-operative scan of an area of interest that includes a location where the device currently resides within the subject's body; and

(D) using the image data from said at least one intra-operative scan to update at least a portion of preoperative or initial intra-operative scan to provide an updated scan that includes a showing of the location of the device.

2. A method according to claim 1 wherein said at least one intra-operative scan comprises a scan that is performed continuously over some period of time while the scanner translates along an axis of scanner rotation.

3. A method according to claim 1 wherein at least one intra-operative scan comprises a plurality of discrete scans performed at different times.

4. A method according to claim 1 wherein the device comprises a catheter.

5. A method according to claim 4 wherein the device has a flexible shaft.

6. A method according to claim 1 wherein the device comprises a guide catheter.

7. A method according to claim 1 wherein the device comprises a guidewire.

8. A method according to claim 1 wherein the device comprises an implantable substance delivery device.

9. A method according to claim 1 wherein the device comprises a dilation catheter having a dilator that is used to dilate the ostium of a paranasal sinus.

10. A method according to claim 9 wherein at least one intra-operative scan is performed to confirm that the dilator is positioned within the paranasal sinus ostium.

11. A method according to claim 9 wherein at least one intra-operative scan is performed to confirm that the ostium has been dilated to a desired size.

12. A method according to claim 9 wherein:

a guide catheter having a distal tip is inserted and advanced to a position where its distal tip is within or adjacent to the sinus ostium to be dilated;

a guidewire is advanced through the guide catheter, through the ostium and into the paranasal sinus; and

the dilation catheter is thereafter advanced over the guidewire to a location where the dilator is positioned within the ostium and useable to dilate the ostium.

13. A method according to claim 12 wherein at least one intra-operative scan is performed to ascertain the location of the distal tip of the guide catheter.

14. A method according to claim 12 wherein the guide catheter has a distal tip radiopaque marker and wherein at least one intra-operative scan is performed to ascertain the location of that distal tip radiopaque marker.

15. A method according to claim 12 wherein at least one intra-operative scan is performed to confirm that the guide catheter has been positioned at an intended location within or adjacent to the sinus ostium.

16. A method according to claim 12 wherein at least one intra-operative scan is performed to ascertain the location of the guidewire.

17. A method according to claim 12 wherein the guidewire is advanced such that a distal portion of the guidewire becomes coiled within the paranasal sinus and wherein at least one intra-operative scan is performed to confirm that a distal portion of the guidewire becomes coiled within the paranasal sinus.

18. A method according to claim 12 wherein at least one intra-operative scan is performed to confirm that the dilator is positioned within the ostium.

19. A method according to claim 18 wherein the dilation catheter has proximal and distal dilator markers and wherein at least one intra-operative scan is performed to ascertain the locations of the proximal and distal dilator markers relative to the ostium that is to be dilated.

20. A method according to claim 12 wherein the dilation catheter includes a distal marker at its distal end and wherein at least one intra-operative scan is performed to ascertain the location of that distal marker.

21. A method according to claim 12 wherein at least one intra-operative scan is performed to confirm that the dilator has been fully advanced out of the distal end of the guide catheter and is capable of expanding.

22. A method according to claim 1 wherein the pre-operative or initial intra- operative scan comprises a CT or MRI scan.

23. A method according to claim 1 wherein said at least one intra-operative scan comprises a CT scan.

24. A method according to claim 1 wherein said at least one intra-operative scan comprises a fluoroscopic scan.

25. A system for performing a procedure within the ear, nose, throat or paranasal sinus of a human or animal subject, said system comprising:

a working device that is insertable through a nostril of the subject and useable to perform, or facilitate the performance of, at least a portion of the procedure; and

a first data set comprising a pre-operative tomographic image of an area of interest;

a display which displays the pre-operative tomographic image of the area of interest;

an intra-operative tomographic imaging device that is useable during performance of the procedure to generate a second data set comprising an intra-operative tomographic image of or within the area of interest; and

a processor that receives the second data set and either i) replaces the first data set with the data set or ii) integrates the second data set with the first data set, thereby updating the tomographic image viewed on the display to include the intra-operative tomographic image.

26. A system according to claim 25 wherein the intra-operative tomographic imaging device provides an intra-operative tomographic image that shows the current location of the working device within the subject's body.

27. A system according to claim 25 wherein the intra-operative tomographic imaging device operates continually over some period of time and the processor is programmed to continually or repeatedly update the displayed tomographic image during that period of time.

28. A system according to claim 25 wherein the intra-operative tomographic imaging device operates during discrete time periods during the procedure and the processor is programmed to update the displayed tomographic image at least once during each discrete time period.

29. A system according to claim 25 wherein the working device comprises a catheter.

30. A system according to claim 29 wherein the catheter has a flexible shaft.

31. A system according to claim 25 wherein the working device comprises a guide catheter.

32. A system according to claim 25 wherein the working device comprises a guidewire.

33. A system according to claim 25 wherein the working device comprises an implantable substance delivery device.

34. A system according to claim 25 wherein the working device comprises a dilation catheter having a dilator that is used to dilate a paranasal sinus ostium.

35. A system according to claim 34 wherein the intra-operative tomographic imaging device provides an intra-operative tomographic image of the paranasal sinus ostium which allows the operator to confirm that the dilator is positioned within the paranasal sinus ostium.

36. A system according to claim 34 wherein the intra-operative tomographic imaging device provides an intra-operative tomographic image of the paranasal sinus ostium which allows the operator to confirm that use of the dilator has caused a suitable amount of dilation of the paranasal sinus ostium.

37. A system according to claim 25 wherein the working device comprises a guidewire that is to be advanced to a position wherein a distal portion of the guidewire is coiled within a paranasal sinus and wherein the intra-operative tomographic imaging device provides an intra-operative tomographic image from which the operator may confirm that a distal portion of the guidewire has become coiled within the paranasal sinus.

38. A system according to claim 25 wherein the intra-operative tomographic imaging device comprises a computed tomography (CT) scanner.

39. A system according to claim 25 wherein the intra-operative tomographic imaging device comprises a magnetic resonance imaging (MRI) device.

40. A system according to claim 25 wherein the intra-operative tomographic imaging device comprises a fluoroscopic scanning device.