Devices, systems and methods useable for treating frontal sinusitis

[0001] This application is a continuation-in-part of copending U.S. patent application Ser. No. 11/150,874 entitled “Devices, Systems and Methods Useable for Treating Sinusitus” filed on Jun. 10, 2005, which is a continuation in part of U.S. patent application Ser. No. 10/944,270 entitled “Apparatus and Methods for Dilating and Modifying Ostia of Paranasal Sinuses and Other Intranasal or Paranasal Structures” filed on Sep. 17, 2004, which is a continuation-in-part of Ser. No. 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 Apr. 21, 2004, the entire disclosures of such earlier filed applications being expressly incorporated herein by reference.

[0002] The present invention relates generally to medical devices and methods and more particularly to minimally invasive, devices, systems and methods for treating sinusitis and other ear, nose & throat disorders.

[0003] In human beings, the frontal paranasal sinuses reside on either side of the forehead adjacent to and above the orbits. The right and left frontal sinuses are divided by an intersinus septum. Each frontal sinus has a natural opening (i.e., an ostium) formed in the posteromedial aspect of the sinus floor. In most patients, a narrow anatomical pre-chamber known as the frontal recess extends between the frontal sinus ostium and the nasal cavity. The frontal recess is a bony structure covered by mucosal tissue. The anterior border of the frontal recess is formed by the posterior wall of the agger nasi cell and the medial aspect of the frontal recess relates to the lateral lamella of the cribriform and the cribriform plate. Mucous normally drains out of the frontal sinus ostium, through the frontal recess, and into the nasal cavity. The ostium and frontal recess are sometimes referred to in combination as the frontal outflow tract (FOT). In many individuals, the FOT is a relatively long passage.

[0004] In patients suffering from acute frontal sinusitis, the FOT may become inflamed and occluded, thereby impeding natural drainage from the frontal sinus cavity and allowing infectious organisms to thrive within the frontal sinus cavity and associated ethmoid air cells. Acute frontal sinusitis is sometimes associated with intracranial and/or ocular complications. Ocular complications that are known to result from frontal sinusitis include thrombosis, thrombophlebitis, cellulites and orbital abscesses. One type of orbital abscess, known as a Pott puffy tumor, is associated with considerable soft tissue swelling over the frontal bone. Intracranial complications associated with frontal sinusitis include meningitis, brain abscess, epidural empyema, subdural empyema, and cerebral empyema.

[0005] In current practice, surgical procedures are performed for the treatment of acute frontal sinusitis only after the condition has failed to respond to conservative therapy (e.g., administration of antibiotics and mucolytic agents along with topical steroids and topical or systemic decongestants) or when other complications are present or when the infection has recurred more than 3-4 times in a year. The surgical procedures used to treat acute frontal sinusitis include functional endoscopic sinus surgery (FESS) procedures as well a open surgical procedures.

[0006] In FESS procedures, a nasal endoscope and other instruments (e.g., seekers, probes, rongeurs, a drills, and bony curettes) are inserted transnasally and used to improve patency of the FOT or otherwise improve drainage from the diseased frontal sinus. This process often involves the performace of an uncinectomy, anterior ethmoidectomy, agger nasi removal, and/or resection of the anterosuperior attachment of the middle turbinate. In some cases, the superior aspect of the nasal septum may be removed in a bilateral frontal sinus drill-out procedure. In many frontal sinus FESS procedures, disease of the anterior ethmoids is also be addressed during the surgery. In some cases, a stent is placed within the surgically altered FOT to maintain its patency in the weeks following the surgery. In cases where a stent is implanted, the patient is typically advised to irrigate the stent several times a day for up to 5-7 weeks after the surgery.

[0007] Postoperatively, it is typically necessary for FESS patients to visit the surgeon periodically for postoperative care, such as debridement, removal of clots, removal of granulation tissue, removal of crust, removal of polyps, etc.

[0008] FESS treatment of frontal sinusitis does have some disadvantages. For example, the FESS procedures are technically complex, accessing disease in the supraorbital frontal sinus cell is difficult, postoperative care can be laborious, confirming the patency of the surgically altered FOT may be difficult during the initial postoperative period.

[0009] Moreover, given the risks associated with the FESS procedure, some patients with relatively mild frontal sinusitis are not considered to be candidates for the procedure even though the available medical therapies may provide them with less than complete relief.

[0010] In the trephination procedure, a small supraorbital incision is made below the medial eyebrow and the underlying periosteum is elevated. A bore hole is then made through the skull bone and into the sinus cavity. The interior or the sinus may then be cleaned and small tubes may be inserted and used for future irrigation or drainage. In some cases, trephination may be performed concurrently with endoscopic frontal sinus surgery. In some patients, the intersinus septum may be removed and a single opening may be created through which both frontal sinuses may drain into the nasal cavity. The main contraindication to the trephination procedure is the presence of an aplastic frontal sinus.

[0011] Other open surgeries, known generally as frontoethmoidectomies, have also been used to treat frontal sinusitis and associated ethmoid disease. These procedures have been performed by various approaches, including those known as the Lynch approach, the Killian method, the Reidel method and the Lothrop or Chaput-Meyer approach.

[0012] Another group of open procedures used to treat frontal sinusitis are known generally as osteoplastic flap procedures. These osteoplastic flap procedures are typically employed only in severe cases where frontal sinusitis is refractory or accompanied by intracranial complications. Osteoplastic flap procedures have been performed by various approaches, including a coronal approach, a midline forehead approach and a brow incision approach. After an initial incision is made by one of these three approaches, a template may be used to outline the frontal sinus. An incision is then made through the periosteum at a location slightly above the outline of the sinus. The periostium is elevated and a saw is used to cut into the frontal sinus. Small cuts may also be made above the glabella to loosen the frontonasal suture. In this manner, an osteomeatal flap is created, exposing the interior of the frontal sinus. The surgeon may then remove the diseased sinus mucosa and may also alter the structure of the sinus and/or FOT, such as by removal of the intersinus septum. The remaining frontal sinus cavity is then packed with autogenous fat or other materials (Gelfoam, Teflon, fat, paraffin, silastic sponge, and cartilage), the osteomeatal flap is replaced and the periostium and skin layers are then closed with sutures. Some modified versions of the osteoplastic flap procedure also include the use of a pericranial flaps and/or cancellous bone grafts.

[0013] In general, open surgical procedures do provide excellent visualization of the interior of the sinus, thereby enabling the surgeon to see and correct a variety of problems. However, these open procedures can be extremely invasive. They also result in at least some visible scarring and typically involve substantial obliteration of existing anatomy to create an open frontonasal communication.

[0014] The prior art has included some disclosure of the use of balloon catheters to dilate anatomical passages and improve drainage from paranasal sinuses. For example, U.S. Pat. No. 2,525,183 (Robison) discloses an inflatable pressure device which can be inserted following sinus surgery and inflated within the sinus. Also, United States Patent Publication No. 2004/0064150 A1 (Becker) discloses balloon catheters wherein a balloon is mounted on a stiff hypotube that may purportedly be pushed into a sinus. The stiff hypotube has a fixed pre-set curve or angle. Additionally, an abstract entitled Balloon Dilatation of Recurrent Ostial Occlusion of the Frontal Sinus, by D. Göttmann, M. Strohm, E.-P. Strecker and D. E. Karlsruhe describes balloon dilatation of recurrent ostial occlusion of the frontal sinus in seven patients suffering from recurring chronic frontal sinusitis who had undergone between two and four prior surgeries for the condition. Using endonasal access the ostium of the frontal sinus was crossed with an angiographic catheter and a hydrophilic guidewire under fluoroscopic control. Then, the stenosed ostium was dilated with a high pressure percutaneous transluminal angioplasty balloon having a deflated diameter of 5 mm and an inflated diameter of 8 mm. This procedure was performed 2 to 8 times in each patient, at intervals of 2 to 12 weeks. The abstract reports that all of these procedures were technically successful and there were no complications. Although the prior art does disclose some uses of balloons to dilate the ostia of paranasal sinuses, the prior art has not disclosed specifically sized or configured balloons or other dilators that may be used to dilate the entire length of a FOT (i.e., the frontal sinus ostium as well as an adjacent frontal recess) in a single step or without the need for repositioning and multiple inflations of the balloon.

[0015] Because the surgical treatments for frontal sinusitis are invasive and associated with various risks and complications, there remains a need for the development of new devices and techniques for treatment of frontal sinusitis with less trauma and less risk of complications. Also, since surgical treatments for frontal sinusitis are typically reserved for only severe or refractory cases, there remains a need for the development of new interventions that go beyond the previously available conservative treatments (e.g., medical therapy with antibiotics, steroids, mucolytics, saline lavage, etc.) but do not involve the tissue trauma.

[0016] The present invention provides improved dilator systems and methods wherein a dilator of suitable length is used to simultaneously dilate the frontal sinus ostia and frontal recesses, and optionally to dilate the ostia of other sinuses as well.

[0017] In accordance with an embodiment of the invention, there is provided a method for improving outflow through the frontal sinus ostium and adjacent frontal recess in a human or animal subject. This method generally comprises the steps of (A) providing a dilator that has a collapsed configuration and an expanded configuration, said dilator being of a length that is approximately as long as or longer than the length of the frontal sinus ostium and frontal recess combined; (B) positioning the dilator such that it occupies the frontal sinus ostium and at least substantially all of the frontal recess while in its collapsed configuration; and (C) causing the dilator to expand to its expanded configuration, thereby dilating the frontal sinus ostium and at least substantially all of the frontal recess. In some embodiments, the dilator may be mounted on a catheter and the catheter may be inserted transnasally and advanced to a location where the dilator is positioned with the frontal sinus ostium and substantially all of the adjacent frontal recess. The dilator may comprise a balloon or any other expandable structure (e.g., an expandable systems of wires, mesh, etc.). In embodiments where the dilator is a balloon, the balloon may be elongated and non-compliant or semi-compliant and, optionally, may be at least partially coated with a protective coating. Examples of materials of which the balloon may be formed include polyethylene terephthalate (PET), Nylon and those materials referred to in U.S. Pat. No. 5,264,260 (Saab) which is expressly incorporated herein by reference. Examples of protective coatings that may be used include but are not necessarily limited to those described in U.S. Pat. No. 5,599,576 (Opolski) and/or U.S. Pat. No. 5,766,158 (Opolski), both of which are expressly incorporated herein by reference. In some embodiemts, the protective coating may comprise a matrix polymer and a reinforcing agent. In some embodiments, a primer layer may optionally be disposed between the balloon surface and the protective coating. The matrix polymer of the protective coating may, for example, comprise a urethane, acrylic or epoxy. The reinforcing agent may, for example, be lamellar, platelet, or fiber-like in structure and may have a higher surface hardness than the surface hardness of the material of which the balloon is formed. Such reinforcing agent may, for example, comprise a micaceous pigment, glass fiber, lamellar platelet, flake pigment, tungsten powder and/or fibers. In some embodiments, the protective coating may have a thickness in the range of about 0.1 mil to about 3 mil and in some embodiments such coating thickness may be in the range of about 0.5 mil to about 2 mil. In some embodiments, the protective coating may further include a crosslinking agent (e.g., aziridine, carbodiimide, urea formaldehyde, melamine formaldehyde condensate, epoxy, isocyanate, titanate, zircoaluminate, zinc crosslinker, silane, etc.). In some embodiments, the protective coating may further include an additive selected from the group consisting of radio pacifiers, anti-slip additives, anti-mar additives, and antimicrobial agents, and therapeutic agents or other therapeutic or diagnostic substances.

[0018] Further in accordance with the invention, there is provided a system that is useable to perform the above summarized method. Such system generally comprises a dilation catheter having a dilator as summarized hereabove and a guide (e.g., a tubular guide through which the dilation catheter is advanced or an elongate guide member such as a guidewire over which the dilation guide catheter is advanced). The guide is useable to guide the positioning of the dilator. In at least some embodiments, the guide may be of substantially fixed shape (e.g., manufactured to a predetermined shape or at least partially malleable so that the surgeon may bend it to a desired substantially fixed shape prior to insertion). In at least some embodiments where the guide has a substantially fixed shape, such shape will include a curve near the distal end of the guide to facilitate positioning of the distal end of the guide within or adjacent to the frontal recess. The guide is insertable through one of the subject's nostrils and advanceable to a position where the distal end of the guide is adjacent to or within the frontal recess. Thereafter, the dilation catheter is advanceable over or through the guide to a position where the dilator is positioned within the frontal sinus ostium and frontal recess (or other ostium or structure to be dilated). Thereafter, the dilator may be expanded to cause dilation of the frontal sinus ostium and substantially all of the adjacent frontal recess (or whatever other ostium or anatomical structure is to be dilated. In at least some embodiments, the dilation catheter may have a length of or less than 50 cm. In at least some embodiments, the dilation catheter may have a length of or less than 42 cm. In at least some embodiments, the dilation catheter may have a length of or less than 25 cm. Also, in at least some embodiments, the dilator may be less than 1 mm wide at its widest point while in its collapsed configuration and more than 3 mm wide at its widest point when in its expanded configuration. Also, the dilator itself may have a have a length of more than 10 mm (e.g., a 24 mm dilator may be used to dilate the frontal sinus ostium and substantially all of the adjacent frontal recess in most adult or fully grown humans. The dilator may comprise a balloon or any other expandable structure (e.g., an expandable systems of wires, mesh, etc.). In embodiments where the dialtor comprises a balloon the balloon may be constructed and/or coated as described in the preceding paragraph hereabove and in the United States Patents incorporated by reference therein.

[0019] Further aspects, details and embodiments of the present invention will be understood by those of skill in the art upon reading the following detailed description of the invention and the accompanying drawings.

[0020] FIG. 1 is a diagram of the paranasal anatomy of a human head wherein a dilation catheter system of the present invention has been inserted and is being used to simultaneously dilate the frontal sinus ostium and adjacent frontal recess.

[0021] FIG. 2 is a sagital sectional view through the right nasal cavity wherein a dilation catheter system of the present invention has been inserted and is being used to simultaneously dilate the frontal sinus ostium and adjacent frontal recess.

[0022] FIGS. 3A-3C are side views of devices that comprise one embodiment of a dilation catheter system of the present invention. FIG. 3A shows a guidewire, FIG. 3B shows a dilation catheter and FIG. 3C shows a tubular guide.

[0023] FIG. 4 is a broken, side elevational view of a rapid exchange embodiment of a dilation catheter device of the present invention.

[0024] FIG. 5 is a partial perspective view of an embodiment of a dilation catheter device of the present invention having a tapered dilation balloon.

[0025] FIG. 6A is a partial perspective view of an embodiment of a dilation catheter device of the present invention having a dilation balloon that incorporates a force concentrating member.

[0026] FIG. 6B is a cross sectional view through line 6B-6B of FIG. 6A.

[0027] The following detailed description, the accompanying drawings and the above-set-forth Brief Description of the 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.

[0028] A number of the drawings in this patent application show anatomical structures of the ear, nose and throat. In general, these anatomical structures are labeled with the following reference letters:

	Nasal Cavity	NC
	Nasopharynx	NP
	Frontal Sinus	FS
	Frontal Sinus Ostium	FSO
	Frontal Recess	FR
	Ethmoid Air Cells	EAC
	Intersinus Septum	ISS
	Sphenoid Sinus	SS
	Sphenoid Sinus Ostium	SSO
	Maxillary Sinus	MS

[0029] The term “diagnostic or therapeutic substance” as used herein is to be broadly construed to include any feasible drugs, prodrugs, proteins, gene therapy preparations, cells, diagnostic agents, contrast or imaging agents, biologicals, etc. Such substances may be in bound or free form, liquid or solid, colloid or other suspension, solution or may be in the form of a gas or other fluid or nan-fluid. For example, in some applications where it is desired to treat or prevent a microbial infection, the substance delivered may comprise pharmaceutically acceptable salt or dosage form of an antimicrobial agent (e.g., antibiotic, antiviral, antiparasitic, antifungal, etc.), a corticosteroid or other anti-inflammatory (e.g., an NSAID), a decongestant (e.g., vasoconstrictor), a mucous thinning agent (e.g., an expectorant or mucolytic), an agent that prevents of modifies an allergic response (e.g., an antihistamine, cytokine inhibitor, leucotriene inhibitor, IgE inhibitor, immunomodulator), etc. Other non-limiting examples of diagnostic or therapeutic substances that may be useable in this invention are described in copending U.S. patent application Ser. No. 10/912,578 entitled Implantable Devices and Methods for Delivering Drugs and Other Substances to Treat Sinusitis and Other Disorders filed on Aug. 4, 2004, the entire disclosure of which is expressly incorporated herein by reference.

[0030] The term “frontal recess” means the natural or surgically altered opening or passageway extending from an ostium or opening in a frontal sinus into the nasal cavity.

[0031] The term “frontal outflow tract” or the acronym “FOT” means an ostium or opening in a frontal sinus along with any frontal recess that extends from that ostium or opening to the nasal cavity.

[0032] Each of the terms “ostium,” “opening of a paranasal sinus” or “opening in a paranasal sinus” as used herein shall mean any accessible opening in a paranasal sinus or cranio-facial air cell, including but not limited to; natural ostia, surgically or medically altered ostia, surgically created or man made openings, antrostomy openings, ostiotomy openings, trephination openings, burr holes, drilled holes, ethmoidectomy openings, anatomical passageways, natural or man made passages, etc., unless otherwise specified.

[0033] The term “working length” as used herein with respect to balloons or other dilators shall mean the length of that portion of the balloon or other dilator that actually contacts and dilates tissue. For example, in the case of a balloon that, when inflated, has a cylindrical midregion that contacts and dilates adjacent tissue and tapered end regions that do not contact and dilate adjacent tissue, the working length of such balloon is the length of the cylindrical midregion that contacts and dilates adjacent tissue.

[0034] Optionally, any of the working devices and guide catheters described herein may be configured or equipped to receive or be advanced over a guidewire or other guide member (e.g., an elongate probe, strand of suture material, other elongate member) unless to do so would render the device inoperable for its intended purpose. Some of the specific examples described herein include guidewires, but it is to be appreciated that the use of guidewires and the incorporation of guidewire lumens is not limited to only the specific examples in which guidewires or guidewire lumens are shown. The guidewires used in this invention may be constructed and coated as is common in the art of cardiology, but may be substantially shorter than those used in cardiology applications. This may include the use of coils, tapered or non-tapered core wires, radiopaque tips and/or entire lengths, shaping ribbons, variations of stiffness, PTFE, silicone, hydrophilic coatings, polymer coatings, etc. For the scope of this invention, these wires may possess dimensions of length between 5 and 120 cm and outer diameter between 0.005″ and 0.050″. In embodiments of the invention where an elongate guide member (e.g., a guidewire) of a substantially fixed shape is specified, such may be accomplished by utilizing a guide member (e.g., guidewire) that is fully or partially formed of rigid or malleable material and is pre-shaped to a desired substantially fixed configuration (e.g., a desired curve near its distal end) prior to insertion into the subject's body.

[0035] It is to be appreciated that various modalities can be used with the devices and methods disclosed herein for navigation and imaging of the devices within the anatomy. For example, the devices disclosed herein may comprise an endoscope for visualization of the target anatomy. The devices may also comprise ultrasound imaging modalities to image the anatomical passageways and other anatomical structures. The devices disclosed herein may comprise one or more magnetic elements especially on the distal end of the devices. Such magnetic elements may be used to navigate through the anatomy by using external magnetic fields. Such navigation may be controlled digitally using a computer interface. The devices disclosed herein may also comprise one or more markers (e.g. infra-red markers). The markers can be used to track the precise position and orientation of the devices using image guidance techniques. Several other imaging or navigating modalities including but not limited to fluoroscopic, radiofrequency localization, electromagnetic, magnetic and other radiative energy based modalities may also be used with the methods and devices disclosed herein. These imaging and navigation technologies may also be referenced by computer directly or indirectly to pre-existing or simultaneously created 3-D or 2-D data sets which help the doctor place the devices within the appropriate region of the anatomy. Examples of specific navigation apparatus and methods that may be used in conjunction with the devices and methods of this invention include but are not limited to those described in co-pending U.S. patent application Ser. No. 11/037,548 entitled “Devices, Systems and Methods For Treating Disorders of the Ear, Nose and Throat,” which is expressly incorporated herein by reference.

[0036] Also, as described more fully hereblow, the devices of the present invention may include visible markers that may be viewed directly or endoscopically to facilitate the desired positioning of the devices within the body.

[0037] FIGS. 1-2 show the use of an embodiment of a dilation catheter system 10 to simultaneously dilate a frontal sinus ostium FSO and adjacent frontal recess FR in a human subject. Frontal recess anatomy has heretofore been generally taught as having an hour glass shape so it was believed that a relatively short dilator (such as a balloon) was all that was needed to dilate most frontal sinus anatomy. Unexpectedly, however, Applicants have discovered that in a fairly large population of patients there are actually multiple constrictions along the frontal recess. As a result, Applicants developed the present invention. In general, the embodiment of the dilation catheter system 10 shown in the drawings comprises a dilation catheter 12, a tubular guide 14 and a guidewire 16. These components of the system 10 are shown in greater detail in FIGS. 4A-4C.

[0038] Generally, at least one of the tubular guide 14 and/or the guidewire 16 will have a predetermined (e.g., substantially fixed) shape (e.g., having a fixed curve near its distal end) prior to its insertion into the body. This fixed shape facilitates easy insertion of the guidewire 16 and/or tubular guide 14 into the frontal recess or other desired location within the nasal cavity or paranasal sinus anatomy. In some instances, one or both of the guidewire 16 and/or tubular guide 14 will be of generally rigid construction and manufactured in the desired predetermined or substantially fixed shape. In other instances, all or a portion of the guidewire 16 and/or tubular guide 14 may be of malleable construction such that the surgeon may bend or pre-form that guidewire 16 or tubular guide 14 to the desired shape prior to its insertion into the subject's body.

[0039] In the particular example shown in the drawings and discussed herebelow, the tubular guide 14 is generally rigid and has a substantially fixed shape. The guidewire 16 is substantially flexible and use of the guidewire is optional. It is to be appreciated, however, that in other embodiments the guidewire 16 may be more rigid and of substantially fixed shape and use of the tubular guide 16 may be optional.

[0040] In this example, the guidewire 16, seen in FIG. 3A, is a flexible sinus guidewire with a soft tip, a length of 100 cm and a diameter of 0.035 inch. This guidewire is commercially available under the name Relieva™ Sinus Guidewire from Acclarent, Inc., Menlo Park, Calif. It will be appreciated, however, that other guidewires and other sizes of guidewires may alternatively be used.

[0041] Also, in this example, the tubular guide 14 as seen in FIG. 3B, comprises a semi-flexible tube with a malleable proximal shaft 30 and a plastic distal portion 32 having a curve 34 formed near its distal end DE. A radiopaque marker 38 is mounted near the distal end DE of this tubular guide 14. This tubular guide is available commercially under the name Relieva™ Sinus Guide Catheter from Acclarent, Inc. of Menlo Park, Calif. This tubular guide 14 is available with a range of curves 32 (i.e., 0°, 30°, 70°, 90° and 110°). Typically, for frontal sinus procedures such as that described herein a curve of 70° is most suitable. It will be appreciated, however, that other guidewires and other sizes of guidewires may alternatively be used.

[0042] The dilation catheter 12 of this example, as seen in detail in FIG. 3C, comprises an elongate catheter body 18 having a proximal end PE and a distal end DE. An elongate balloon 20 is mounted on the catheter body 18 at a location near its distal end DE. This balloon 20 has a working length L that is specifically sized to extend from the frontal sinus ostium FSO through substantially all of the frontal recess FR, thus rendering this balloon 20 capable of dilating substantially the entire frontal outflow tract (i.e., the frontal sinus ostium and all or nearly all of the adjacent frontal recess), without the need for repeated inflations of the balloon 20 with longitudinal repositioning of the catheter between inflations. In this regard, although it may be deemed appropriate to repeat inflation of the balloon 20 more than one time to dilate the frontal sinus ostium FSO and adjacent frontal recess FR, no longitudinal repositioning of the catheter body 18 will be required between such inflations. This dilation catheter 12 is available commercially under the name Relieva™ Sinus Balloon Catheter from Acclarent, Inc., Menlo Park, Calif. A fixed guidewire 28 may optionally extend from the distal end of the dilation catheter 12, as seen in FIG. 3C. Such fixed guidewire 28 may allow the dilation catheter 12 to be used without a separate guidewire 16.

[0043] The actual working length L and diameter of the balloon 20 may vary depending on the anatomy, age and/or size of the subject. The working length of the balloon can be between about 12 mm and 30 mm. For example, the following table sets forth a non-limiting example different balloon sizes that may be provided for treatment of frontal sinusitis in subjects of normal body size and weight ranging in age from childhood to adulthood.

Typical
Patient Age	Dilator (e.g., Balloon) Width	Dilator (e.g., Balloon)
Range	(Fully Expanded)	Working Length
>17	about 5 mm to about 7 mm	about 24 mm
14-17	About 4 mm to about 7 mm	About 21 mm
10-14	About 3 mm to about 6 mm	About 18 mm
6-10	About 2 mm to about 5 mm	About 15 mm
<6	About 2 mm to about 4 mm	About 12 mm

[0044] Applicant's current data suggests that a balloon 20 having a working length of about 24 mm and a fully expanded width of about 5 mm to about 7 mm may be used to expand the frontal sinus ostium FSO as well as substantially all of the adjacent frontal recess FR in most adult or fully grown humans without the need for repeated inflations of the balloon 20 or without longitudinal repositioning of the catheter between inflations.

[0045] The procedure by which the devices are inserted and used may vary somewhat from surgeon to surgeon and/or from case to case. One particular, non-limiting example of such a procedure is described herebelow with reference to the showings of FIGS. 1 and 2.

[0046] During performance of this procedure, an endoscope, such as a Karl Storz Hopkins II 4 mm scope with a 70 degree viewing angle may optionally be inserted into the nose and used, alone or in combination with other imaging techniques, to view the advancement and positioning of devices during the procedure in accordance with known practice or as described in U.S. patent applications Ser. Nos. 10/829,917; 10/944,270; 11/037,548; 11/193,020; 11/150,847; 11/116,118, each of which is expressly incorporated herein by reference. Alternatively or additionally, radiographic imaging (e.g., C-arm fluoroscopy) may be used to view the positioning and guide the placement of devices during the procedure in accordance with known practice or as described in U.S. patent applications Ser. Nos. 10/829,917; 10/944,270; 11/037,548; 11/193,020; 11/150,847; 11/116,118, each of which is expressly incorporated herein by reference. Also, alternatively or additionally, the devices used in this procedure may be equipped with sensors and image guidance technology may be used to view the positioning and guide the placement of devices during the procedure in accordance with known practice or as described in U.S. patent application Ser. No. 11/116,118, which is expressly incorporated herein by reference.

[0047] In this example, the guidewire 16 may be initially introduced, distal end first, into the lumen of the tubular guide 14. Thereafter, the tubular guide 14 (with the guidewire 16 inserted therein) is inserted through the subject's nostril with the curve 32 of the tubular guide 14 pointing upwardly. The distal end DE of the tubular guide 14 is maneuvered through the middle meatus to a position where its distal end DE is adjacent to and in alignment with the frontal recess FR. The guidewire 16 is then advanced out of the open distal end DE of the tubular guide 14, through the frontal recess FR, through the frontal sinus ostium FSO and into the frontal sinus FS. In some cases, it may be desirable to push a length of the guidewire into the frontal sinus FS such that it becomes coiled within the sinus cavity as seen in FIGS. 1 and 2. This tends to deter inadvertent slippage of the guidewire 16 out of position and the coiled guidewire 16 within the frontal sinus FS may be viewed by radiographic means to verify that the FOT has been successfully wired.

[0048] It is to be appreciated that, although the dilation catheter 12 shown in FIGS. 1-2 and 3C is an over-the-wire type device that has a guidewire lumen that extends from one end of the catheter to the other, various other guidewire lumen configurations and/or fixed guidewire tips may be employed instead. For example, a guidewire may be affixed to and extend distally from the distal end of the catheter body 18. Or, as shown in the alternative example of FIG. 4, a rapid exchange embodiment of the dilation catheter 12a may be utilized. This rapid exchange embodiment of the dilation catheter 12a comprises a catheter body 18a having a proximal hub 22a on its proximal end and a guidwire lumen that extends from a side port 42 located between the proximal and distal ends of the catheter body 18a though an opening in the distal end of the catheter body 18a. In this manner, the guidewire 28 will extend through only a distal portion of the catheter body 18a and the proximal portion of the guidewire will be outside of the catheter body 18a as shown.

[0049] It is to be further appreciated that, in at least some embodiments, substances (e.g., therapeutic or diagnostic substances, radiographic contrast medium, medicaments, lavage fluid, etc.) may be injected through a lumen of the catheter body 18. In some embodiments, the guidewire 28 may be smaller in diameter than the guidewire lumen such that substances may be injected through the guidewire lumen even while the guidewire is positioned therein.

[0050] Thereafter, the proximal end PE of the guidewire 16 is inserted into the distal opening of a guidewire lumen that extends through the dilation catheter 12 and the dilation catheter 12 is advanced over the guidewire 16 and through the lumen of the tubular guide 14 to a position where the balloon 20 occupies the frontal sinus ostium FSO and substantially all or all of the adjacent frontal recess FR. An inflator device (e.g., the Relieva™ Sinus Balloon Inflation Device, Aclarent, Inc., Menlo Park, Calif.) is then connected to the inflation sidearm 26 of the dilation catheter's proximal hub 22 and is used to inflate the balloon 20 to its expanded configuration. Typically, in applications where the balloon 20 is used to dilate the frontal sinus ostium FSO and adjacent frontal recess FR, this balloon will be inflated to a pressure of approximately 4-12 ATM. The balloon 20 may reach its nominal (target) diameter at an inflation pressure of approximately 4-8 ATM. This inflation may be repeated one or more times at the discretion of the surgeon, but no repositioning of the balloon 20 is required between successive inflations. In this manner, the frontal sinus ostium FSO and frontal recess FR are dilated, thereby improving patency of the FOT and facilitating drainage from and healing of the diseased frontal sinus FS.

[0051] If the working length L of the balloon 20 is longer than the length of the frontal sinus ostium FSO and adjacent frontal recess FR, a proximal portion of the balloon may be permitted to remain within the distal end of the tubular guide 14 or another suitable sheath or constraining structure such that only a portion of the balloon 20 becomes inflated. This essentially provides a balloon 20 of adjustable length. Alternatively or additionally, the diameter of the balloon 20 may also vary over its length. For example, a 24 mm long balloon 20 may have a first region (e.g., 16 mm) which inflates to a first diameter (e.g., 7 mm) and a second region that inflates to a second diameter (e.g., 5 mm). In another example, shown in FIG. 5, a dilation catheter 12b may comprise a catheter body 18b having a balloon 20b mounted thereon, such balloon 20b being may be continuously tapered such that one end of the balloon 20b inflates to a first diameter and the other end of the balloon 20b inflates to a smaller second diameter, with a continuous diametric taper therebetween.

[0052] Also, alternatively or additionally, as shown in FIGS. 6A and 6B, an embodiment the dilation catheter 12c may comprise a catheter body 18c having a balloon 20c mounted thereon, wherein such balloon 20c incorporates one or more force concentrating members 44 (such as longitudinal wires embedded in the wall of the balloon 20c) or other surface protrusion(s) that concentrate the dilatory force of the balloon in specific area(s) rather than allowing the balloon 20c to exert the same outwardly directed dilatory force about its entire diameter.

[0053] Various other balloon shapes and balloon constructions may be incorporated in the dilation catheters 12, 12a, 12b or 12c including those described in the parent patent applications of which this application is a continuation-in-part. Some particular non-limiting examples of such shapes and/or constructions include the following:

• • [0054] The balloon or other dilator may additionally be constructed to deliver diagnostic or therapeutic substances to adjacent tissues, such as through pores, coatings, micro-penetrating members, etc.
  • [0055] The balloon material may be of varying thickness along the length of the balloon to enhance folding or to permit it to expand in an intentionally non-uniform fashion.
  • [0056] To prevent “winging” the balloon may be preshaped with set ‘hinge’ areas that naturally fold when the balloon is deflated—these hinge areas may run longitudinally along the balloon or may be helically located.
  • [0057] The catheter shaft extending through the balloon may be longitudinally moved by the operator to lengthen or shorten the balloon length to adjust to different anatomies.
  • [0058] The distal tip of the balloon may be curved to facilitate placement and also to orient the tip away from the skull base.

[0059] As seen in FIG. 2, The medial wall of the orbit (specifically the lamina papyracea) is reinforced by ethmoid air cells that form a “honeycomb” structure between the medial wall of the orbit and the frontal recess FR. In at least some applications of the present invention, dilation of the frontal recess FR causes bone to become cracked, fractured, rearranged or repositioned and, in at least some cases, results in compression or remodeling of one or more ethmoid air cells EAC.

[0060] 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 to do so would render the embodiment or example unsuitable for its intended use. Also, where the steps of a method or process are described, listed or claimed in a particular order, such steps may be performed in any other order unless to do so would render the embodiment or example not novel, obvious to a person of ordinary skill in the relevant art or unsuitable for its intended use. 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.