Frederick A. Kuhn

University of Toronto, Toronto, Ontario, Canada

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Publications (60)92.28 Total impact

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    Christopher T Melroy · Frederick A Kuhn
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    ABSTRACT: We sought to evaluate an instrument that allows a drug-eluting catheter to be inserted into the ethmoid sinuses and to demonstrate its safety and reproducibility in a cadaver model. A drug-eluting catheter was placed into 12 cadaveric anterior and posterior ethmoid sinuses by use of a trocar-based insertion device. The device's position was analyzed with computed tomographic scans, and postprocedural dissection was performed. The drug-eluting catheter system was successfully inserted in all ethmoid sinuses without injury to the medial orbital wall, skull base, or sphenoid face. The final position of the distal tip of the catheter averaged 8.1 mm (root mean square [RMS], 3.3 mm) from the skull base, 5.6 mm (RMS, 3.5 mm) from the sphenoid face, and 5.0 mm (RMS, 3.5 mm) from the lamina papyracea; the proximal tip was at the face of the ethmoid bulla and 17.1 mm (RMS, 3.5 mm) below the skull base. A trocar-based instrument can relatively safely and reproducibly introduce a drug-eluting catheter into the ethmoid sinuses without injuring the skull base, lamina papyracea, or sphenoid face. This device may allow safe topical drug delivery into the ethmoid sinuses and serve as a vehicle to treat chronic ethmoid sinusitis with direct and sustained topical therapy.
    Preview · Article · Oct 2009 · The Annals of otology, rhinology, and laryngology
  • Karen A Bednarski · Frederick A Kuhn
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    ABSTRACT: Synechiae and ostial stenosis are common and troublesome complications following endoscopic sinus surgery. Many investigators have advocated the use of stents to minimize the risk of postoperative stenosis while others have found their use to be of no benefit. This article reviews the advantages and disadvantages of various stents used in sinus surgery, and discusses such innovations as drug-releasing stents.
    No preview · Article · Oct 2009 · Otolaryngologic Clinics of North America

  • No preview · Article · Sep 2009 · Otolaryngology Head and Neck Surgery
  • Karen Bednarski · Frederick Kuhn · Christopher Melroy

    No preview · Article · Sep 2009
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    ABSTRACT: Less invasive instruments such as balloon catheters are available for sino-ostial dilation during endoscopic sinus surgery (ESS). Currently, balloon catheter position is confirmed under fluoroscopic visualization. Radiation exposure has been an area of concern. This study was initiated to determine surgeon radiation exposure when fluoroscopy is used during ESS with balloon catheters. A multi-center, prospective evaluation of surgeon radiation exposure was conducted. For three months, 14 sinus surgeons wore dosimeters to record radiation exposure while using C-arm fluoroscopy during balloon catheter-aided sinus surgery. One dosimeter was placed at collar level (chest), outside the lead apron and another dosimeter was placed on a finger (extremity). These dosimeters were sent for readings. Deep, eye, and shallow radiation dose for each surgeon was calculated. Thirteen chest badges recorded annualized averages of 191.08, 193.54, and 187.69 mrems for deep, eye, and shallow exposure respectively. Eleven ring badges recorded 584.00 mrems. A recent publication reported low levels of surgeon radiation exposure during ESS with balloon catheters. This study validates radiation exposure among experienced surgeons is well below the annual occupational radiation exposure limit of 50,000 mrem. With vigilant technique and education, fluoroscopy reliance can be minimized.
    No preview · Article · Jul 2009 · Otolaryngology Head and Neck Surgery
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    ABSTRACT: The frontal recess is the drainage pathway that connects the frontal sinus to the anterior ethmoid sinus. Mechanical obstruction is the primary cause of chronic frontal sinusitis with or without a secondary inflammatory process. Eosinophilic inflammation is one of the underlying causes for chronic rhinosinusitis. OBJECTIVES/HYPHOTHESIS: To evaluate long-term frontal sinus patency after endoscopic frontal sinusotomy in chronic rhinosinusitis patients and to assess the effect of eosinophilic inflammation on frontal sinus patency. Retrospective chart review. Symptom assessment and archived endoscopic photographs were prospectively collected on patients who underwent frontal sinusotomy between 7-1-1999 and 12-31-2000. Subjective symptom improvements were evaluated using the SNOT-20 = 20-item Sino-Nasal Outcome Test. Objective findings of endoscopic frontal sinus patency were documented by archived digital photography. A total of 161 patients with 294 frontal sinuses who underwent endoscopic frontal sinus surgery in the 18 months had an average follow-up of 45.9 months. The patient population was divided into two groups: 58 patients had eosinophilic CRS (ECRS), and 103 patients had CRS without eosinophils (non-ECRS). The mean follow-up for patients with ECRS is 61.6 months and 37.0 months for non-ECRS patients. The non-ECRS patients had a documented endoscopic frontal sinus patency of 90%, and the ECRS patients had an endoscopic frontal sinus patency of 85%. The overall frontal ostium patency rate for all patients was 88.0%. Long-term endoscopic confirmation of frontal ostium patency demonstrates that endoscopic frontal sinusotomy can yield high quality, durable results. There was no significant difference in patency results between ECRS and non-ECRS patients. Laryngoscope, 2009.
    No preview · Article · Jun 2009 · The Laryngoscope
  • Yvonne Chan · Frederick A Kuhn
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    ABSTRACT: This review is timely and relevant because rhinosinusitis is a disease process that is heterogeneous in its clinical and pathologic manifestations. Therefore, no one causative factor has been identified that fully accounts for all rhinosinusitis. The purpose of this review is to provide a succinct update of rhinosinusitis classification, pathophysiology, and management given the new movement toward evidence-based guidelines. The term rhinosinusitis reflects the concurrent inflammatory and infectious processes that affect the nasal passages and the contiguous paranasal sinuses. The most recent classification scheme is intended primarily to guide clinical research and divides rhinosinusitis into four categories: acute bacterial rhinosinusitis, chronic sinusitis with nasal polyposis, chronic rhinosinusitis with nasal polyposis, and allergic fungal rhinosinusitis. The goals of treatment include reduction of mucosal edema, reestablishment of sinus ventilation, and eradication of infecting pathogens. Multiple therapies are available for the management of chronic rhinosinusitis, including antibiotics, hypertonic and isotonic saline irrigations or sprays, topical and systemic glucocorticords, antileukotriene agents, and endoscopic sinus surgery. Rhinosinusitis is a common medical problem that interferes with patient quality of life and loss of work productivity. Because of the heterogeneity that underlies its pathology, no one treatment regimen exists for the management of rhinosinusitis.
    No preview · Article · May 2009 · Current opinion in otolaryngology & head and neck surgery
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    ABSTRACT: The primary objective was to assess the long-term effectiveness of balloon catheter sinusotomy. Patients who had sinus ostia dilated with balloon catheters were prospectively evaluated 1 year after surgery with nasal endoscopy, a CT scan, and the Sino-Nasal Outcome Test (SNOT-20). Sixty-six patients (202 sinuses) were examined. One hundred seventy-two of 202 sinus ostia (85%) were endoscopically patent, 1 percent (2/202) were nonpatent, and ostial patency could not be determined by endoscopy in 28 of 202 (14%). In these "indeterminate" sinuses, the CT scans were normal in 13, implying functional patency in 91.6 percent of sinuses (185/202). Sinus CT scan scores were 1.95 at 1 year versus 8.89 at baseline (P < 0.001), and 1-year SNOT-20 scores (0.91) were significantly improved from baseline (2.14, P < 0.0001). Balloon catheter sinusotomy results were durable over the study period, showing long-term effectiveness.
    No preview · Article · Sep 2008 · Otolaryngology Head and Neck Surgery
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    ABSTRACT: Assess two-year postoperative clinical outcomes for patients receiving balloon catheter sinusotomy. Patients who had sinus ostia dilated with balloon catheters were prospectively evaluated two years after surgery by Sinonasal Outcome Test (SNOT-20) and computed tomographic (CT) scan. Sixty-five patients (195 ballooned sinuses) were followed for two years after surgery, including 34 "balloon-only" patients and 31 "hybrid" patients. SNOT-20 symptom scores were significantly improved from baseline (0.87 vs 2.17 baseline, P < 0.001) and stable compared to six months and one year; this was the case for both balloon-only (1.09 vs 2.09, P < 0.001) and hybrid (0.64 vs 2.26, P < 0.001) patients. Lund-MacKay CT scores were significantly improved from baseline (2.69 vs 9.66, P < 0.001) and stable compared to one year, confirmed for both balloon-only (1.75 vs 5.67, P < 0.015) and hybrid (3.25 vs 12.05, P < 0.001) subsets of patients. A total of 85% of patients reported improvement of their sinus symptoms, with 15% same and 0% worsened. Revision treatment was required in seven of 195 sinuses (3.6%) in six of 65 patients (9.2%). Patients who receive balloon catheter sinusotomy in endoscopic sinus surgery have significant improvement in symptoms two years after surgery. Radiographic evidence also confirms resolution of disease after two years. This demonstrates durability of clinical results previously reported at 24 weeks and one year after surgery.
    Preview · Article · Sep 2008 · Otolaryngology Head and Neck Surgery
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    ABSTRACT: Objective Less invasive instruments such as balloon catheters are now available to dilate sinus ostia during endoscopic sinus surgery (ESS). Currently, balloon catheter position is confirmed under fluoroscopic visualization, which emits ionizing radiation. Radiation exposure has long been an area of concern. This study was initiated to determine radiation exposure to surgeons who used fluoroscopy with balloon catheters during ESS.
    No preview · Article · Aug 2008 · Otolaryngology Head and Neck Surgery
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    ABSTRACT: Objective The objective of this study is to assess the safety and efficacy of managing chronic ethmoid sinusitis with an implantable drug-eluting spacer filled with triamcinolone acetate.
    No preview · Article · Aug 2008 · Otolaryngology Head and Neck Surgery
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    ABSTRACT: The aim of this study was to determine the extent of radiation exposure to the patient and the surgeon in balloon catheter dilation. Dosimeters were used to record radiation exposure to both patients and surgeons. The mean radiation dose per sinus treated and per patient treated was calculated for each dosimeter location. The mean patient dose (108 sinuses treated in 34 patients), was 0.32 mSv per sinus and 1.02 mSv per patient over the eye and 1.33 mSv per sinus and 4.22 mSv per patient over the temple. The average total fluoroscopy time was 3.6 minutes per patient. The average number of sinuses treated was 3.2. The mean surgeon dose at the chest (254 sinuses in 89 patients) was 0.025 mSv per sinus and 0.072 mSv per patient. The mean surgeon dose at the hand (182 sinuses in 68 patients) was 0.009 mSv per sinus and 0.023 mSv per patient. The use of fluoroscopy in balloon catheter dilation exposes both the patient and surgeon to very low doses of radiation.
    No preview · Article · Mar 2008 · Otolaryngology Head and Neck Surgery

  • No preview · Article · Jan 2008 · Otolaryngology Head and Neck Surgery
  • Frederick A Kuhn · Kevin K Wong · Bradford Mechor · Amin R Javer

    No preview · Article · Sep 2007 · The Laryngoscope
  • Source
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    ABSTRACT: The aim of this study was to further evaluate the safety and effectiveness of balloon catheter devices to dilate obstructed sinus ostia/perform sinusotomy. Through a prospective, multicenter evaluation, safety was assessed by rate of adverse events, patency was determined by endoscopic examination, and sinus symptoms were determined by the Sino-Nasal Outcome Test (SNOT 20). At the conclusion of the 24-week analysis, endoscopy determined that the sinusotomy was patent in 80.5% (247 of 307) sinuses and nonpatent in 1.6% (5 of 307), and could not determine ostial patency status in 17.9% (55 of 307). Of the ostia visualized on endoscopy, 98% were patent (247 of 252), while 2% (5 of 252) were considered nonpatent. SNOT 20 scores showed consistent symptomatic improvement over baseline. Revision treatment was required in 3 sinuses (3 of 307 sinuses, 0.98%) in 3 patients (3 of 109 patients, 2.75%). Balloon catheter technology appears safe and effective in relieving ostial obstruction. Patients were pleased and indicated that they experienced symptomatic improvement.
    Preview · Article · Aug 2007 · Otolaryngology Head and Neck Surgery
  • Marc G Dubin · Frederick A Kuhn · Christopher T Melroy
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    ABSTRACT: Maximal medical therapy is poorly defined in chronic sinusitis treatment. To objectively evaluate the radiographic response of chronic rhinosinusitis without polyposis after 3 and 6 weeks of oral antibiotics. Thirty-five patients with confirmed chronic sinusitis without polyposis (disease apparent on initial computed tomography [CT] with appropriate symptom duration) were prescribed 6 weeks of antibiotics. When possible, culture-directed antibiotics were used; otherwise clindamycin was used empirically. A CT was performed after 3 and 6 weeks of therapy. CTs were then graded by the Lund-Mackay system. Demographic data were reviewed. Of the 35 patients, 16 underwent all 3 CT scans and completed all 6 weeks of antibiotics. Three patients completed only 3 weeks of antibiotics, and 16 did not undergo the interval 3-week CT. Six patients (38%) had statistically significant improvement in their CT scans between weeks 3 and 6. In this subset of patients who improved, 37% of their overall radiographic improvement occurred in the 3- to 6-week treatment interval. No prognostic variables predicted which patients would radiographically improve after 3 weeks of antibiotics. Some patients achieve radiographic improvement and disease resolution after the completion of a 3-week course of antibiotics. Therefore, maximal medical therapy for chronic sinusitis may consist of longer than 3 weeks of therapy to ensure maximal benefit.
    No preview · Article · Feb 2007 · Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology
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    ABSTRACT: In the era of external sinus surgery, access to the frontal sinus was very straightforward. Its position high in the frontal bone allowed relatively safe approaches to the anterior table, which would be removed in a variety of fashions. The osteoplastic fl ap with obliteration gained acceptance in the 1950s as the standard of management in chronic frontal sinus infl ammatory conditions [11]. Its purpose was to make the sinus nonfunctional and no longer an issue. From an instrumentation standpoint, no specialized equipment was needed to approach this relatively superfi cial structure. The fi rst specialized instrument designed specifi cally for use in the frontal sinus was the Van Alyea cannula (Fig. 3.1), which was used for transnasal irrigation of the frontal sinus in patients that had not been operated on. The introduction of endoscopic sinus surgery brought about a paradigm shift in sinus surgery and a renaissance to the study of sinus anatomy and physiology. Using endoscopic methods, surgeons began to treat chronic infl ammatory disease in a functional manner rather than in an extirpative or obliterative manner. They sought to preserve the anatomy and enhance the natural drainage pathways of the paranasal sinuses [28]. As all prior transnasal sinus instrumentation was designed to be used with a speculum and headlight, the advent of endoscopic sinus surgery necessitated the development of new instrumentation, which would complement endoscopy. While the maxillary, ethmoid, and sphenoid sinuses can be approached with straight instrumentation and 0° endoscopes, the frontal sinus drainage pathway lies at an upward angle to the anteroposterior axis of the ethmoid sinuses. It is above and behind the insertion of the middle turbinate attachment to the lateral nasal wall. Standard instrumentation would allow neither access nor safe removal of tissue in this area. In 1989, Kuhn and Bolger developed frontal sinus instruments with Karl Storz (Tuttlingen, Germany) that would allow safe dissection in this area. This set, known as the Kuhn-Bolger Frontal Sinus Instrument Set, consists of two frontal sinus curettes, one frontal ostium seeker, and six frontal recess giraff e forceps (Fig. 3.2). These advances in instrumentation and the operative techniques associated with them [2, 3, 7, 12, 14, 16, 18, 19, 21, 27] allowed better success in the frontal recess, and endoscopic frontal sinusotomy became the standard for the primary operative management of chronic frontal sinusitis. The anatomy of the frontal recess is discussed elsewhere in this publication;, it is an inverted funnelshaped area, which extends from the internal frontal ostium down along the skull base ending at the anterior ethmoid artery (Fig 3.3). It is extensively and variably pneumatized by a variety of frontal recess cells-the agger nasi cell, four types of frontal cells, supraorbital ethmoid cells, suprabullar and frontal bullar cells. These cells, originally described by Van Alyea, have been revisited and defi ned over the last 15 years [1, 17, 24, 25]. Anatomically speaking, this is a narrow and confi ned area that is bordered medially by the anterior aspect of the middle turbinate, laterally by the lamina paprycea, anteriorly by the agger nasi region, and posteriorly by the skull base. The ease of endoscopic access to this small and intensely pneumatized area is in stark contrast to the facile external approach to the frontal sinus. Several tenets of functional frontal sinus surgery are particularly germane to dealing with dissection of the frontal recess. One is to remove the frontal recess cells completely, taking full advantage of the medial frontal sinus fl oor to enlarge the ostium and there by relieve potential sources for frontal recess obstruction. Enlarging the frontal sinus outfl ow tract below the ostium allows more effi cient mucociliary clearance from the frontal sinus and reduces the likelihood of frontal recess narrowing secondary to edema and scarring. Most importantly, however, is preservation of all frontal recess mucosa; this allows restoration of function without scarring. Fibrin clot does not adhere to intact mucosa. There is less likelihood of granulation tissue, fi brous scarring, and frontal sinus contracture. Any frontal recess mucosa inadvertently removed increases the likelihood of these problems. Anything which improves enlarging the drainage pathway while preserving the mucosa and mucociliary clearance is advantageous to patient outcomes. The operative technique for endoscopic frontal sinus and frontal recess surgery is detailed elsewhere in this book at great length. The purpose of this chapter is to detail the instrumentation that has advanced frontal sinus surgery and review the proper use of this instrumentation in light of these tenets of frontal sinus surgery.
    No preview · Article · Jan 2007

  • No preview · Article · Aug 2006 · Otolaryngology Head and Neck Surgery
  • Marc G Dubin · Frederick A Kuhn

    No preview · Article · Jul 2006 · American Journal of Otolaryngology
  • Frederick A Kuhn
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    ABSTRACT: This article the most useful procedures into into a comprehensive integrated approach to frontal sinus surgery. It begins with the least invasive and progresses to the most invasive procedure in a step-by-step fashion, which can be applied as needed. The selection of procedure is governed the patient's disease anatomy,and the surgeons skill. The least invasive procedure that can be used should be attempted first, and then, if more is needed, other procedures can be added, either at the same sitting or in subsequent revisions.
    No preview · Article · Jul 2006 · Otolaryngologic Clinics of North America

Publication Stats

1k Citations
92.28 Total Impact Points

Institutions

  • 2009
    • University of Toronto
      • Department of Otolaryngology - Head and Neck Surgery
      Toronto, Ontario, Canada
  • 2000-2009
    • Sinus & Nasal Institute of Florida
      St. Petersburg, Florida, United States
  • 2008
    • Loma Linda University
      لوما ليندا، كاليفورنيا, California, United States
  • 2007
    • University of North Carolina at Chapel Hill
      • Department of Otolaryngology/Head and Neck Surgery
      North Carolina, United States
  • 2005
    • Johns Hopkins University
      • Department of Otolaryngology - Head and Neck Surgery
      Baltimore, Maryland, United States
  • 2001
    • University of British Columbia - Vancouver
      Vancouver, British Columbia, Canada
  • 1998
    • Saint Louis University
      • Department of Otolaryngology
      Сент-Луис, Michigan, United States
  • 1996-1997
    • Georgia Health Sciences University
      • Department of Surgery
      Augusta, Georgia, United States
  • 1994-1995
    • Augusta Health
      Fishersville, Virginia, United States