A Golden Experience: Fifty Years of Experience Managing the Frontal Sinus

Transcription

1 The Laryngoscope VC 2015 The American Laryngological, Rhinological and Otological Society, Inc. Contemporary Review A Golden Experience: Fifty Years of Experience Managing the Frontal Sinus Philip G. Chen, MD; Peter-John Wormald, MD; Spencer C. Payne, MD; William E. Gross, MD; Charles W. Gross, MD Objectives/Hypothesis: The frontal sinus is one of the most anatomically complex and inaccessible of the paranasal sinuses. As a result, surgeons have continually tried to improve surgical management of the frontal sinus. The senior author (C.W.G.) shares 50 years of experience managing the frontal sinus. Data Sources: PubMed literature search. Review Methods: Review of the literature regarding landmark innovations in frontal sinus surgery. Results: Open approaches established that the frontal sinus is accessible, and in certain circumstances, such as with large osteoma or papilloma, are still required. The endoscope changed the surgical landscape and allowed for greater finesse and decreased morbidity. Sinus balloon dilation is the newest change in frontal sinus management and shows promise in properly selected cases. Conclusion: Surgery of the frontal sinus continues to evolve and improve. Although there are new techniques, the older techniques are still pertinent. Key Words: Frontal sinus, chronic sinusitis, endoscopic sinus surgery, Lothrop procedure, balloon dilation, stent. Laryngoscope, 126: , 2016 INTRODUCTION Management of patients with diseases of the frontal sinuses is among the most challenging problems faced by sinus surgeons. During the now 50-year career of the senior author (C.W.G.), much has changed in our understanding of anatomy, access, and disease processes affecting the frontal sinus, as well as in the evolution of surgical management. In this review, the authors present an overview of progress made in managing patients afflicted with diseases in the most inaccessible and variable of the paranasal sinuses. METHODS Anatomy The frontal sinus (FS) consists of a pneumatization into the frontal bone of the skull. It is the last paranasal sinus to From the Department of Otolaryngology Head and Neck Surgery, University of Texas Health Science Center San Antonio (P.G.C.), San Antonio, Texas; the Department of Otolaryngology Head and Neck Surgery, University of Virginia (S.C.P., C.W.G.), Charlottesville, Virginia; the Murfreesboro Clinic Otolaryngology (W.E.G.), Murfreesboro, Tennessee, U.S.A.; and the Department of Otolaryngology Head and Neck Surgery, University of Adelaide (P-J.W.), Adelaide, South Australia, Australia. Editor s Note: This Manuscript was accepted for publication August 12, Spencer C. Payne, MD, serves as a consultant for Medtronic, Stryker, and Acclarent, and also conducts research funded by Acclarent. Peter-John Wormald, MD, receives royalties from Medtronic, Integra, and Scopis, and is a consultant for Neilmed. The authors have no other funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Philip G. Chen, MD, 8300 Floyd Curl Dr., MC 7777, San Antonio TX p_g_chen@hotmail.com DOI: /lary develop, usually completed in early adulthood. 1 However, one or both frontal sinuses remain hypoplasticin1%to7%ofpatients. 2 Frontal sinus anatomy is highly variable and often complex. Adding confusion to this is the inconsistent terminology. The agger nasi cell (ANC) is a key structure 3 present in 89% to 98.5% of patients. 4,5 It is the anteriormost ethmoid cell, located above the axilla of the middle turbinate. The frontal recess (FR) is an anatomically variable space posterior to the frontal beak, which continues posterior to the bulla lamella. The middle turbinate is the medial border of the FR, whereas the lamina papyracea serves as the lateral extent. Poor pneumatization of the ANC results in a thick frontal beak that causes narrowing of the FS outflow. The frontal ostium is the narrowest space in the transition from the frontal sinus into the frontal recess, best seen on the parasagittal computed tomography (CT) scan. A bony intersinus septum divides the right and left frontal sinuses. Cells that pneumatize into this septum can obstruct the frontal ostium and are termed intersinus septal cells. 6 Additional cells can obstruct the frontal ostium, as initially described by Schaeffer 7 and Van Alyea. 8 The descriptions commonly used today were popularly described by Kuhn 6 and later modified 9 (Table I). Understanding the configuration of frontal cells is paramount to performing thorough FS surgery. 10 The anatomy has been masterfully covered in detail elsewhere. 11 Pathology Both benign and malignant tumors can originate in the frontal sinus; however, inflammatory pathologies encompass the vast majority of surgeries performed on the FS. Although uncommon, acute frontal sinusitis can lead to intracranial complications and must be considered, even in the pediatric age group. 12 Secondary to its location on the skull base, combined

2 Cell Type Agger nasi Type 1 Type 2 Type 3 Type 4 Frontal bullar Suprabullar Interfrontal sinus septal TABLE I. Kuhn 6 Classification of Cells of the Frontal Recess and Frontal Sinus. Wormald 9 modifications in italics. Description Anterior to middle turbinate, first ethmoid cell Single cell above agger nasi 2 or more cells above agger nasi, but inferior to frontal beak Cell(s) pneumatizing into frontal ostium, but < 50% height of frontal sinus Isolated frontal cell Cell(s) pneumatizing into frontal ostium and exceeding 50% height of frontal sinus Cell from suprabullar region that pneumatizes along skull base into frontal sinus Cell(s) above ethmoid bulla, but does not enter frontal sinus Pneumatization of interfrontal sinus septum, between the right and left frontal sinuses with complex anatomy, the FR can be difficult to clear surgically. Even after adequate surgery, inflammation and polyp recurrence most often occur first in the FS ostial region. 13 Mucocele formation occurs if the frontal ostium is occluded. Early Years External procedures of the frontal sinus are interesting from an historical perspective, and some are still used today. External approaches aim to either drain the frontal sinus (externally or intranasally) or ablate it. This can be accomplished in the following ways: 1) create a trephine for drainage or access; 2) remove an anterior or orbital wall; 3) create an osteoplastic flap (without cosmetic defect); 4) enlarge or reconstruct the frontal ostium; and 5) obliterate the sinus cavity. 14 In the late 1800s, open procedures to the FS were described but were often associated with cosmetic deformity. 15,16 Later, Hoffman described the osteoplastic frontal sinusotomy. 17 However, in effort to avoid removing the frontal bone, Lynch 18 and Howarth 19 reported results with the external frontoethmoidectomy. These procedures are rarely used today in the traditional form, but modifications described by Neel et al. appeared to improve outcomes. 20 Lothrop reported removal of the interfrontal sinus septum, the superior nasal septum, and floor of the frontal sinus through an orbital incision. 21 This procedure was considered too difficult and risky until it was reintroduced as an endoscopic procedure without need for an external incision. Draf described a classification for the extent of surgery performed on the FS (Table II). 22 He modified the original Lothrop procedure by using an endonasal approach to remove the superior nasal septum and interfrontal sinus septum to join the right and left drainage pathways. Hence, the Draf 3 is also termed endoscopic modified Lothrop procedure (EMLP). The osteoplastic flap with fat obliteration was employed by Bergara in the 1940s 23 and was popularized in the 1960s by Goodale and Montgomery. 24 This procedure became the gold standard for frontal sinus surgery, with success rates up to 90%. However, these cavities are difficult to monitor, and complications include poorly healed incisions, blood loss, cerebrospinal fluid leak, mucocele formation, and frontal osteitis. The osteoplastic flap is still used today, and may be necessary in cases of osteoma or papilloma extending far laterally or intracranially beyond the reach of an endoscopic approach. Endoscopic-modified Lothrop procedure can sometimes be used in these cases to avoid obliteration. Present Age For decades, management of the sinuses was either performed with a headlight and nasal speculum or with an external approach. The headlight endonasal approach yielded poor visualization, whereas the microscope did not afford angled views into the sinuses. Further, early imaging was limited to low-resolution X-rays. In the 1980s, two technological changes led to novel innovation in the management of the sinuses. Although endoscopes had been used as early as 1901 by Hirschman to visualize the maxillary sinus, 25 technology greatly improved with the rigid Hopkins rod telescope in the 1960s. In the 1970s, Messerklinger used the rigid endoscope to view the paranasal sinuses 26 ; subsequently. Stammberger, 27 Wigand, 28 and Draf 29,30 popularized the technique. Meanwhile, CT scanning was becoming more commonplace and provided better anatomical understanding. Kennedy et al. 31 combined these technologies to advance surgery of the frontal sinus and helped introduce endoscopic sinus surgery in the United States. Early management of the FS was based on obliteration of the diseased sinuses, but understanding has evolved to address causes of obstruction and to create a functioning sinus. Functional endoscopic sinus surgery was hinged on the concept that the osteomeatal complex (OMC) was the common drainage pathway of multiple sinuses. We now understand that the pathogenesis of chronic rhinosinusitis is more complex than simple OMC obstruction, although this was an important foundation upon which endoscopic sinus surgery (ESS) was based. The wide availability of high-resolution triplanar (coronal, sagittal, and axial) imaging has dramatically improved our understanding of FS anatomy. The additional detail has advanced the ability to identify and clear all cells obstructing the FS and even expand the confines of a patient s anatomy, as in the case of EMLP. 22,32 The high-resolution CT imaging also helps the surgeon preoperatively identify potential pitfalls in an effort to decrease surgical complications. 33 The extent of frontal sinus surgery has been described as Draf types I, IIa and IIb, and III. 22,34 Draf I consists of anterior ethmoidectomy without manipulation of the frontal outflow tract, Type Draf I Draf IIa Draf IIb Draf III TABLE II. Descriptions of Endonasal Frontal Sinus Procedures. 34 Description Simple drainage: remove the anterior ethmoidal cells to the skull base, without manipulating the frontal sinus ostium. Extended drainage: remove the floor of the frontal sinus from the lamina papyracea to the nasal septum, and from the anterior to the posterior frontal sinus walls. Draf IIa, with additional removal of the entire floor by drilling of the ipsilateral frontal beak to widen the anterior posterior diameter Median drainage: Remove the frontal sinus floor (Draf IIa) with drilling of the frontal beak (Draf IIb), with additional removal of the superior nasal septum and interfrontal sinus septum. 803

3 and embodies the functional idea of ESS based on the assumption that removing OMC blockage improves sinus drainage. This concept is further espoused by the minimally invasive sinus technique (MIST). 35,36 However, patients in MIST trials had a relatively low disease load. In one study, no more than 27% of the patients had frontal disease. 36 Draf IIa encompasses the removal of cells obstructing the FS outflow. The success of Draf IIa has been well established. 37,38 Complete clearance can be challenging, and meticulous care is required. Many surgeons shy away from this area, thereby increasing the risk of surgical failure. 37,39 Fortunately, more comprehensive anatomical understanding has led to techniques improving access and visualization. For example, in order to facilitate usage of a zero-degree endoscope, multiple authors have advocated removal of the anterior lamella of the agger nasi, located at the axilla of the middle turbinate (MT) The theoretical concern that manipulating the axilla causes MT destabilization and lateralization has not borne out. 43 The axillary flap technique further decreases scarring by preserving mucosa overlying the axilla. 41 The Draf IIb extends the Draf IIa by additionally removing the frontal sinus floor, which can include the frontal beak, to widen the frontal ostium. Although this provides a patent neo-ostium intraoperatively, removal of the beak results in a wide area of exposed bone. Combined with the inflammation of chronic sinusitis, the exposed bone yields an intense fibrotic reaction that leads to scarring and stenosis postoperatively. In cases of inflammatory disease, the Draf III is preferred. The Draf IIb can be useful for isolated frontal sinus disease without pansinusitis or for improving access to remove small frontal sinus tumors. 44 The Draf III (EMLP) creates one large frontal sinus neoostium by unifying the right and left FS by removing the intersinus septum, superior nasal septum, and frontal beak. 22,32 The maximum dimensions are obtained by removing the frontal process of the maxilla until a small amount of skin is exposed, the frontal beak until the anterior table is clearly visualized, and lowering the frontal T (formed by the septum and middle turbinates) to the first olfactory neuron. 45 This procedure is timeintensive, with slightly higher risk than Draf IIa, but is proven efficacious. Although the majority of EMLPs are performed for recalcitrant frontal sinusitis, EMLP can also be used to address frontal sinus tumors and mucoceles including those that form after prior frontal sinus obliteration. 46 In one of the earliest reports of the EMLP with an adequate follow-up period (average 1 year), there were no complications, and 95% of the neo-ostia remained patent. 47 Further, although symptom indices were not available at the time, the patients reported subjective improvement. The EMLP also had a lower cost than frontal sinus obliteration, and the sinus cavities were easier to monitor than after obliteration. More recent single-surgeon cohorts, 48,49 single institution, 50 and meta-analysis 51 have supported the efficacy of EMLP. In 223 chronic rhinosinusitis (CRS) patients who underwent EMLP, a 95% success was achieved, with an average 45- month follow-up. 36 For patients with 5-year follow-up data, the ostium size stabilized after 24 months. This finding varies somewhat from another study, which reported an initial success of 80% that dropped to 70% after 10 years. 49 It is possible that mixed pathologies led to the latter finding because they found different revision rates depending on pathology. The most current meta-analysis reported an 86% patency rate, with symptom improvement in 82%. 51 The EMLP is an established and proven surgery, but the exact role continues to be defined. A recent study suggests a role for primary EMLP in selected patients, but the risks and extra surgical time may not warrant such an initial approach. 36 In general, pediatric sinusitis is managed medically, but chronic sinusitis can manifest in children. Typically, adenoid hypertrophy should be addressed first, but sinus surgery is appropriate if disease remains. 52 Concerns regarding alteration of facial growth appear unfounded. 53 Often overlooked in discussions of frontal sinus surgery is the role of the septum. 54 Endoscopic septoplasty is relatively easy to perform in most cases. Given the improved visualization and access to the frontal recess, one should have a low threshold to perform a septoplasty. 55 Trephination of the frontal sinus has been used for hundreds of years and fortunately has become decreasingly morbid. Frontal sinus minitrephination has been described to help locate the frontal sinus ostium by irrigating the sinus with fluoresceinstained saline. 56 Additionally, planning the 3-mm skin incision through hair of the medial eyebrows or in existing glabellar creases camouflages the incision with excellent cosmetic results. 57 The advent of image-guided surgery expanded the ability to perform thorough surgery. Although it should not (and cannot) ever replace comprehensive anatomic understanding, it provides an additional level of information during FS surgery. Surgeons must be familiar with the system and its limitations and must never become complacent due to the presence of this, or any, technology. Frontal Sinus Stenting and Fillers Stenting the frontal sinus dates back over a century ago to using a gold tube. 58 Later, Lynch s original description of the external frontoethmoidectomy included tube placement in the newly created tract. 18 Subsequent findings in a canine model suggested that flexible stents helped prevent fibrosis and osteoblastic activity compared with rigid stents. 59 The role of stenting, however, continues to be debated. The most obvious potential benefit is the separation of wound edges to prevent synechia formation and subsequent stenosis. Further, filling the dead space prevents the collection of blood clot, fibrin, and crusting that can obstruct the outflow tract. A stent may also serve as a matrix for reepithelialization. Although potential benefits exist, there are legitimate concerns. Perloff and Palmer discovered formation of biofilms on stents after only 1 to 6 weeks. 60 The role of biofilms in CRS 61,62 and surgical failure is established ; therefore, biofilmharboring stents are potential sources of chronic infections. Further, in its severest form, toxic-shock syndrome has been reported. 66 Perhaps the most common situation to use stents is in a significantly narrowed FS outflow tract. Hosemann et al. 67 identified a 16% stenosis rate when the frontal ostium was > 5 mm but a 33% stenosis rate when it was smaller. Additionally, stenosis exceeded 50% when the opening was < 2 mm. Naidoo et al. found similar resultant cicatricial scarring with narrow frontal ostia. 37 Of note, neither of these studies used stents. A variety of outcomes have been reported with stents; many were uncontrolled case series, which make it difficult to draw definite conclusions Use of a silastic stent after Draf III found no difference in patency or symptoms. 71 Li et al. 72 first reported use of a mometasone-eluting bioabsorbable implant in rabbit maxillary sinuses. Since then, the Propel mometasone-eluting stent (Intersect ENT, Menlo Park, CA) has received substantial attention. In a number of studies, the stent decreased inflammation and scarring compared to a 804

4 placebo stent. However, its use in the frontal sinus is currently off-label. A variety of other dissolvable materials have been studied as options for drug delivery, but use in the frontal sinus has not been extensively studied An additional study addressed the off-label use of carboxymethylcellulose foam with dexamethasone and showed no benefit when paired with postoperative saline irrigations and oral steroids. 81 In addition to corticosteroids, chitosan is a novel compound that may improve wound healing 82 and potentially decrease frontal ostial stenosis. 83 The future of stenting and fillers continues to evolve, and introduction of newer drug-eluting and chitosan-based options show promise. Balloon Dilation The Relieva Balloon Sinuplasty system (Acclarent, Menlo Park, CA) was released in Subsequently, a nonrandomized prospective trial of 107 patients indicated 98% sinus ostia patency at 24 weeks, 85 with follow-up reporting positive results. 86,87 Prior to the release of these initial multicenter results, a number of case series were published. The first to focus on efficacy in more advanced frontal sinus disease was published by Catalano and Payne. 88 A total of 29 sinuses with modified Lund stage of at least 2 of 3 were dilated, and 48.3% showed radiographic improvement at 6 months. Excluding patients with nasal polyposis, eight of 13 sinuses showed improvement. The authors concluded that balloon dilation could be used in frontal disease, but efficacy may be limited in polypoid sinusitis. Plaza et al. 89 challenged the belief that balloon dilation could not be used in treating chronic sinusitis with nasal polyps (CRSwNP). In a randomized trial of balloon sinus dilation versus traditional Draf I or IIa, this group recruited CRSwNP patients with completely opacified frontal sinuses on CT. They reported dramatic improvement in Lund-McKay scores after dilation and also demonstrated equivalent outcomes in sinus permeability. Unfortunately, permeability is an undefined term. Another prospective study found a 65% to 66% failure rate in accessing the frontal sinus. 90 The authors ended the study early due to the low cannulation success; however, this rate is lower than other studies and is likely attributed to their definition of failure. A Cochrane Database review of the existing literature also challenged the use of balloon dilation, but only the study by Plaza et al. 89 met inclusion criteria. 91 In addition to primary frontal exploration, several case series have evaluated the use of balloon dilation in the revision frontal patient. One series consisted of seven patients who successfully maintained FS patency after dilation of frontal stenosis. 92 Luong et al. 93 reported similar results. Despite a large body of evidence regarding the feasibility and efficacy of FS dilation, the procedure remains controversial (even among the authors) because efficacy is not necessarily demonstrable across the myriad of sinusitis subtypes and severities. Further, others have voiced concern over the rising usage of balloon dilation, which may be at the expense of more advanced techniques and adequate FS surgical training. 94 At minimum, balloon dilation is a safe and effective procedure in select patients with mild to moderate disease. Further, balloon dilation does not preclude future endoscopic sinus surgery if warranted. Discussion When the osteoplastic frontal sinus procedure was introduced in the 1960s, the specialty of otolaryngology was not as sophisticated as today. Indeed, the specialty was being reborn, having been largely freed from treating acute infection. At the same time, pioneers led the field into a new era with advances in otology and management of oncological diseases of the head and neck. However, many practicing otolaryngologists at that time were not trained in major or complicated surgical procedures. Therefore, it is no wonder that there was significant reluctance to undertake the osteoplastic flap introduced by Goodale and Montgomery. 24 The senior author (C.W.G.) was a second-year otolaryngology resident when Dr. Montgomery held a course at Massachusetts Eye and Ear Infirmary, in Boston, Massachusetts, to demonstrate the osteoplastic flap. Dr. Montgomery chose the senior author (C.W.G.) to perform the surgery a resident who had never performed it. The resident rather nervously performed the surgery in the operating room while Dr. Montgomery explained the video feed to the attendees from the auditorium. Not only did this convince the attendees that the procedure could be done by less than an expert (although this is not suggested by the authors), but it also cemented Charles W. Gross s 50-year interest in rhinology. As history attests, the osteoplastic procedure progressed to become the accepted standard procedure, largely replacing the previous standard, the Lynch procedure. Until the 1980s, little significant surgical advancement other than illumination and refinement of surgical instrumentation occurred regarding the osteoplastic procedure. With the introduction of endoscopic sinus surgery, a new surge of interest occurred. The 1980s and 1990s witnessed enormous development as sinus surgery became less morbid and widely accepted. Endoscopic sinus surgery even became acceptable in children for whom only acute drainage procedures previously had been routine. The concept of removal of obstructions prohibiting mucociliary clearance led to the development of several different procedures aimed at opening the frontal recess area. Many of these procedures were intended to progressively clear the frontal outflow tract: Draf I, IIa and IIb, and III. The Draf III was used primarily after less aggressive approaches failed. At that time, many patients were referred to the University of Virginia in Charlottesville, Virginia, after multiple prior unsuccessful procedures. The team decided that a new concept was needed. Cadaver studies and literature review resulted in an endoscopic modification of the abandoned external Lothrop procedure. This endoscopic modification of course is made feasible through the use of the endoscope and modern surgical tools. One of the problems with performing surgery in such confined surgical field is visualization and accessibility. In addition to the endoscope, the modification of the originally described tissue shaver/drill, as originally developed by Drs. House and Urban for acoustic neuroma surgery, was important and has led to the modern tissue shavers (misnomered as microdebriders) that are so widely used today. 95,96 CONCLUSION The 50-year anniversary is termed the golden one, and over a career spanning 50 years, the senior author (C.W.G.) has had the golden opportunity to witness and participate in the most rapid changes in treatment of rhinologic disease (and medicine) seen in history. In 1954, MacBeth stated, the treatment of chronic frontal sinusitis has remained one of the most unsatisfactory items in rhinology. 25 As demonstrated in this article, the frontal sinus remains a challenge for otolaryngologists, but the authors disagree with the statement that it is now unsatisfactory. This is an exciting time as the understanding of pathology affecting the frontal sinus expands. With this knowledge, we can better explore how to best address disease, with limited morbidity to our patients. 805

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