Anatomic misconceptions regarding the agger nasi cell: A preliminary analysis utilizing endoscopic anatomic dissection and three-dimensional computed tomography.

The agger nasi cell is a key anatomic landmark in endoscopic frontal sinus surgery. However, discord amongst authors regarding anatomic definition and prevalence raises questions of its suitability as a surgical landmark. The purpose of this investigation is to evaluate the agger nasi cell using radiographic imaging correlated with endoscopic anatomic dissection to consider the cell's role as a surgical landmark and to explore if three-dimensional computed tomography (3D-CT) technology can provide enhanced insight into this anatomy. CT scans of 11 cadaveric sinonasal complexes were studied using triplanar CT or 3D-CT scanning with stereoscopic 3D imaging. Endoscopic dissections were performed and video recorded. Attention was given to identify agger nasi pneumatization and its origin. Pneumatization of the agger nasi region was noted in 4/11 cases (36.4%) (in two cases the pneumatization arose from the frontal recess, in two from a true agger nasi cell). The agger nasi region appeared as solid unpneumatized bone in 4/11 cases (36.4%). In 3/11 cases (27.3%) limited pneumatization was noted, bordering on but not pneumatizing the agger nasi proper. It may be confusing for otolaryngologic surgeons in training to rely on the "agger nasi cell" as a surgical landmark due to misconceptions regarding the anatomy, prevalence and anatomic definitions. Using standard CT scans to teach anatomy may have shortcomings as compared to the gold standard of surgical dissection. However, new 3D-CT holds promise to more accurately reflect small microanatomic features and provide an improved road map of a patient's anatomy in surgery.

Anosmia following middle nasal concha resection: An anatomic and developmental review with clinical correlation.

Losing the sense of smell can be associated with a significant decrease in quality of life. Fortunately, this occurs infrequently with modern paranasal sinus surgery that has stressed minimally invasive, tissue-sparing principles. However, over time, more extensive surgical applications have emerged that incorporate increased tissue removal. Post-operative period sequelae can occur, including anosmia. Understanding the potential implications of expanded tissue removal, such as middle nasal concha (turbinate) resection, is clinically important and is facilitated by an understanding of anatomy. Our understanding of anatomic nuances is enhanced through an appreciation of embryonic and fetal development. We herein review the developmental anatomy of the middle nasal concha of the ethmoid sinus and olfactory nerve area as it relates to middle nasal concha removal during endoscopic sinus surgery. We present images from our analysis of 12 embryonic and fetal specimens that highlight the important relationship between the middle nasal concha and olfactory nerves. We also review the clinical issues surrounding turbinate preservation versus resection and present a clinical correlation to underscore the uncommon but significant complication of anosmia following sinus surgery with middle nasal concha resection. We highlight knowledge gaps, discuss case selection and review surgical technique modifications for middle nasal concha surgery to reduce the chance of this complication in the future.

The Anterior Ethmoidal "Genu": A Newly Appreciated Anatomic Landmark for Endoscopic Sinus Surgery.

Human sinonasal anatomy varies widely between patients, challenging surgeons operating in the sinuses. Ethmoid sinus anatomy is so variable it has been referred to as a labyrinth. Accordingly, reliable, consistent anatomic landmarks aid surgeons operating in this region. The goal of this investigation was to explore our observations and hypothesis that the ethmoidal bulla and the uncinate process are not entirely separate structures but rather attach, and the attachment could potentially provide a landmark for surgeons performing ethmoid and frontal recess surgery. Ethmoid sinus anatomy was studied in 57 sinonasal complexes through a variety of methods including gross anatomic dissection, endoscopic dissection and 3D CT stereoscopic imaging. The uncinate process and ethmoidal bulla were noted to fuse at the superior aspect of the hiatus semilunaris in 57/57 cases, forming a genu-like feature in the anterior ethmoid. This consistent anatomic feature related closely to the frontal sinus drainage pathway, which drained medial to it in 44/57 (77%) cases. The anterior ethmoidal "genu" appears to be an excellent anatomic feature that surgeons can use during ethmoid and frontal recess surgery. High resolution 3D stereoscopic CT scan is capable of demonstrating sinonasal anatomy in a detailed fashion previously only achieved by cadaveric dissection. This technology can potentially allow for a virtual dissection of a patient's anatomy prior to surgery and could improve minimally invasive procedures and reduce complications. Clin. Anat. 32:534-540, 2019. © 2019 Wiley Periodicals, Inc.

The Ponticulus Ethmoidalis: A Newly Appreciated Anatomic Landmark in Endoscopic Sinus Surgery.

INTRODUCTION: Ethmoid sinus anatomy is so variable it has been referred to as a "labyrinth." Accordingly, this provides a challenge for surgeons performing ethmoidectomy. Identifying consistent anatomic features or landmarks within the ethmoid sinus can aid surgeons performing sinus surgery. The goal of this investigation was to determine if subtle anatomic features are consistently present within the retrobullar recess and could potentially serve as a reliable landmark for surgeons performing ethmoid surgery. MATERIALS AND METHODS: Ethmoid sinus anatomy was studied in 60 sinonasal complexes through several methods including gross anatomic dissection, endoscopic dissection and 3-D CT stereoscopic imaging. RESULTS: Review of gross sagittal sinonasal specimens revealed that the retrobullar recess was present in all specimens and a tissue bridge was noted emanating from the basal lamella deep within the retrobullar recess in 23/24 gross sagittal specimens; in 1/24 specimens it was quite small or difficult to appreciate. In the radiographic analysis, the tissue bridge was noted in 17/18, in 1/18 it was not appreciated. In the endoscopic dissections it was noted in 17/18, in 1/18 it was small or not appreciated. CONCLUSION: The small tissue bridge, or ponticulus within the retrobulbar recess was seen in nearly all ethmoid sinuses studied leading us to venture that could be used in surgery to orient surgical dissection through the basal lamella into the posterior ethmoid region.

Piezoelectric surgical device in endoscopic sinus surgery: an initial clinical experience.

Revision endoscopic sinus surgery presents special challenges, such as the need to remove thick osteoneogenic bone close to the orbit or skull base. Currently available drills and microdebriders have shortcomings for this task, including risk to the underlying periorbita or dura. Recently, piezoelectric ultrasound technology has been used to remove bone while preserving adjacent soft tissue structures. This technology has been effective in several areas of the body, and it logically follows that it may have beneficial rhinologic applications. The purpose of this medical communication is to report an initial clinical experience with piezoelectric technology in revision sinus surgery. The piezoelectric surgical device was used during revision endoscopic sinus surgery in 14 patients in the author's practice from June 2006 to January 2009. All patients had an underlying bone component to their sinus condition, such as osteoneogenesis adjacent to the orbit or skull base. The piezoelectric surgical device performed successfully in removing osteoneogenic bone, and no complications were noted from its use. Piezoelectric surgical technology generates low-frequency ultrasound that dissects bone and appears to offer an option to mechanical drill instrumentation when used during endoscopic sinus surgery to address thick osteoneogenic bone. The clinical experience reported herein shows initial feasibility of the technology in selected cases of sinus surgery. On the basis of the favorable observations from this clinical experience, further exploration and discussion would appear to be valuable.

Spontaneous CSF leaks: a paradigm for definitive repair and management of intracranial hypertension.

OBJECTIVE: To report our outcomes with the repair of spontaneous cerebrospinal fluid (CSF) leaks and to demonstrate how management of underlying intracranial hypertension improves outcomes. STUDY DESIGN: Retrospective review of spontaneous CSF leaks treated at the University of Pennsylvania Health System from 1996 to 2006. Data collected included demographics, nature of presentation, body mass index (BMI), site of skull base defect, surgical approach, intracranial pressure, and clinical follow-up. RESULTS: Fifty-six patients underwent repair of spontaneous CSF leaks. Eighty-two percent (46 of 56) were obese (average BMI 36.2 kg/m(2)). Nine patients had multiple CSF leaks. Fifty-four patients (96%) had associated encephaloceles. Fifty-three CSF leaks (95%) were successfully repaired at first attempt (34 months of follow-up). Intracranial pressures averaged 27 cm H(2)O. Patients were treated with acetazolamide or, in severe cases, with a ventriculoperitoneal shunt. CONCLUSIONS: Spontaneous CSF leaks have the highest recurrence rate of any etiology. With treatment of underlying intracranial hypertension coupled with endoscopic repair, the success rate (95%) approaches that of other etiologies of CSF leaks.

Physiologic alterations in the murine model after nasal fungal antigenic exposure.

OBJECTIVE: To determine whether a recently developed murine model of fungus-induced sinonasal inflammation demonstrated alterations in ciliary activity and expression of inflammatory cytokines. STUDY DESIGN: A prospective randomized controlled study of rhinosinusitis after fungal antigenic sensitization was performed with intraperitoneal aspergillus antigen injection followed by intranasal antigen challenge for 4 weeks. Saline solution was used in a parallel fashion for control animals. SUBJECTS AND METHODS: Six mice were used to validate the model. Additional 15 mice were used for ciliary beat frequency (CBF) analysis and cytokine expression with multiplex technology. Mean values for degree of inflammation, secretory hyperplasia, CBF, and cytokine expression were compared. RESULTS: Histologic analyses demonstrated dense chronic inflammation in aspergillus-challenged animals versus sparse inflammatory cells in controls. Significant differences in mean of aspergillus-challenged versus control animals were observed in degree of inflammation (P < 0.01), secretory hyperplasia (P < 0.01), CBF (P < 0.00002), IL-1alpha (P < 0.0002), IL-1beta (P < 0.0003), IL-4 (P < 0.02), TNF-alpha (P < 0.02), and RANTES (P < 0.01). CONCLUSION: Alteration in baseline CBF accompanied by increased expression of specific inflammatory cytokines was observed in aspergillus-challenged mice.

Gene expression analysis in sinonasal polyposis before and after oral corticosteroids: a preliminary investigation.

OBJECTIVE: To characterize gene expression in sinonasal polyps and to gain insight into change in expression after oral corticosteroid treatment. STUDY DESIGN AND METHODS: Nasal polyps were obtained before and after oral corticosteroid treatment and gene expression was analyzed with a focused gene array technique. RESULTS: Pretreated sinonasal polyps demonstrated high gene expression for chemokine and leukotriene receptor genes (CCR2, CCR5, CX3CL1, and LTB4R) in all patients. After treatment, the global effects of corticosteroids were evident on gene expression. CONCLUSIONS: Gene array techniques hold promise as a research method in sinonasal polyposis. The potential benefits, as well as the potential challenges, in using these research methods will be discussed.

Safety and outcomes of balloon catheter sinusotomy: a multicenter 24-week analysis in 115 patients.

OBJECTIVE: The aim of this study was to further evaluate the safety and effectiveness of balloon catheter devices to dilate obstructed sinus ostia/perform sinusotomy. METHODS: 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). RESULTS: 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%). CONCLUSION: Balloon catheter technology appears safe and effective in relieving ostial obstruction. Patients were pleased and indicated that they experienced symptomatic improvement.

Endoscopic management of inverted papilloma.

PURPOSE OF REVIEW: Inverted papillomas are uncommon benign tumors that may occur in the sinonasal tract. Because of their tendency towards recurrence and their potential for malignant transformation, complete en bloc resection has been the standard treatment modality. With the application of minimally invasive surgical techniques in the management of sinonasal disease processes, transnasal endoscopic removal of inverted papillomas is gaining in acceptance. The following represents a review of the current literature regarding sinonasal inverted papilloma and its clinical management. RECENT FINDINGS: The recent literature has further refined the technique of endoscopic resection of inverted papillomas by delineating essential principles and applying new technologies, such as image guidance and angled endoscopic drills. Modified approaches and methodology have been described to address tumors originating in particular anatomic locations. At the same time, new information relevant to the diagnosis and surveillance of inverted papillomas has been published, regarding the role of imaging, serum tumor markers, and human papillomavirus. SUMMARY: Growth in experience with the endoscopic management of inverted papillomas has led to evolving technical improvements and innovations. In most tumor locations, the completeness of resection achieved by a skilled endoscopic surgeon is equivalent, if not superior, to that attained with an open approach. In some instances, an endoscopic exploration with tumor resection may help define the site of tumor attachment and direct adjunctive open procedures when indicated. Long-term outcomes studies with sizeable patient cohorts will be needed to define the role of various surgical strategies in the optimal management of inverted papilloma.

Development of a murine model of chronic rhinosinusitis.

OBJECTIVE: The aim of this study was to develop a mouse model of chronic eosinophilic rhinosinusitis. STUDY DESIGN: Mice were sensitized to Aspergillis fumigatus (Af) extract by intraperitoneal injection. The animals subsequently received nasal challenges with Af extract 3 times per week for 12 weeks. Sinonasal complexes were studied histologically by the study otolaryngologists and pathologists to characterize the inflammatory response. SETTING: Animal care facility at an academic institution. RESULTS: A chronic eosinophilic inflammatory response was evoked in all study animals. Statistical analysis was performed for inflammation, secretory cell hyperplasia, mast cells, and eosinophils. There were very significant differences (P<0.0005) between control and study mice in all categories. CONCLUSION: Prolonged nasal challenge of Af extract creates an inflammatory response in murine nasal mucosa that mimics human chronic eosinophilic rhinosinusitis. SIGNIFICANCE: A murine model for chronic rhinosinusitis is reported that may facilitate future investigations into disease pathophysiology. EBM RATING: B-2.

Management of cerebral vascular structures during endoscopic treatment of encephaloceles: a clinical report.

OBJECTIVES: Otolaryngologists are increasingly being called upon to treat patients with cerebrospinal fluid leak and encephaloceles. The endoscopic approach to the skull base through the nose and paranasal sinuses has proven effective and is well tolerated by patients. With its more widespread and frequent use, unusual cases and potential complications are becoming more apparent. METHODS: Treatment of two clinical cases in which a cerebral vascular structure was encountered during endoscopic treatment of an encephalocele is presented, and the condition is reviewed. RESULTS: Two patients presented after a skull base injury that occurred during endoscopic sinus surgery. In each case the initial treating surgeon attempted endoscopic repair of a cerebrospinal fluid leak, but the repair failed and the leak persisted. Upon referral to the author, in each case, a traumatic encephalocele with an active leak was apparent, and during repair a cerebral vessel was encountered. It appeared that the vessel had been "pulled down" into the skull base defect with the encephalocele's migration into the sinonasal cavity. CONCLUSIONS: This unusual clinical condition is discussed along with the potential complications that can result from it. Otolaryngologists who treat encephaloceles should be aware of the possibility of encountering a cerebral vessel and should understand the potential complications and management options.

Safety and feasibility of balloon catheter dilation of paranasal sinus ostia: a preliminary investigation.

OBJECTIVES: Endoscopic sinus surgery (ESS) is an effective option for managing patients in whom medical therapy for rhinosinusitis fails. However, ESS is not always successful, and serious complications can occur. New techniques and instrumentation that improve outcomes and reduce complications would be seriously welcomed. Innovative catheter-based technology has improved treatment of several conditions such as coronary artery disease, peripheral vascular disease, and stroke. Recently, catheter devices have been developed for the paranasal sinuses. Cadaver studies confirm the potential use of these devices in rhinosinusitis. The objective of this investigation was to ascertain the feasibility and safety of these newly developed devices in performing catheter-based dilation of sinus ostia and recesses in patients with rhinosinusitis. METHODS: A nonrandomized prospective cohort of 10 ESS candidates was offered treatment with a new technique of balloon catheter dilation of targeted sinus ostia. The frontal, maxillary, and sphenoid sinuses were considered appropriate for this innovative catheter-based technology. The primary study end points were intraoperative procedural success and absence of adverse events. RESULTS: A total of 18 sinus ostial regions were successfully catheterized and dilated, including 10 maxillary, 5 sphenoid, and 3 frontal recesses. No adverse events occurred. Mucosal trauma and bleeding appeared to be less with catheter dilation than is typically observed with ESS techniques. CONCLUSIONS: Dilation of sinus ostial regions via balloon catheter-based technology appears to be relatively safe and feasible. Larger multicenter clinical trials are now warranted to further establish safety and to determine the role of this new technique.

Spontaneous cerebrospinal fluid leaks: a variant of benign intracranial hypertension.

OBJECTIVES: Previous reports indicate that elevated intracranial pressure (ICP) may cause spontaneous cerebrospinal fluid (CSF) leaks. In this study we examined the clinical diagnosis of benign intracranial hypertension (BIH) in this population using the modified Dandy criteria. METHODS: We performed a retrospective review of clinical data and measurements of ICPs after surgical repair. RESULTS: Sixteen patients with spontaneous CSF leaks were surgically treated from 1996 to 2002. In 11 patients with CSF pressure measurements, strict adherence to the modified Dandy criteria definitively confirmed a diagnosis of BIH in 8 patients (72%) and a likely diagnosis in the 3 remaining patients. The mean ICP was 31.1 cm H20 (range, 17.3 to 52 cm H2O), and 81% of the patients were obese middle-aged women. Clinically, all patients had signs and/or symptoms of elevated ICP, such as headache (91%), pulsatile tinnitus (45%), hypertension (45%), balance problems (27%), and visual complaints (18%). Surgical repair was 100% successful in leak cessation over a mean follow-up of 14.1 months. CONCLUSIONS: Most patients with spontaneous CSF leaks fulfill the modified Dandy criteria; thus, this disorder appears to be a variant of BIH. Further investigation is needed to determine the exact cause of elevated CSF pressures in this group and whether medical or surgical treatments to correct the intracranial hypertension are warranted.

Endoscopic management of cerebrospinal fluid rhinorrhea.

Cerebrospinal fluid rhinorrhea and meningoencephaloceles extending into the nasal cavity from the anterior, middle, and posterior cranial fossae often are managed by otolaryngologists. A thorough understanding of the underlying pathophysiology, management principles, and treatment options is essential to achieve optimal outcomes. Surgical and medical management is highly individualized and depends on many factors, including etiology, anatomic site, and underlying intracranial pressure. This article highlights the history, physiology, pathophysiology, diagnosis, surgical techniques, and postoperative care relevant to nasal cerebrospinal fluid leaks and encephaloceles.

Outcomes for endoscopic resection of sinonasal squamous cell carcinoma.

OBJECTIVES: Preliminary data suggest efficacy for the endoscopic approach for sinonasal malignancy. The purpose of this study is to evaluate the effectiveness of the endoscopic approach for the resection of sinonasal squamous cell carcinoma (SCC). STUDY DESIGN: Retrospective analysis of patients undergoing endoscopic resection of sinonasal SCC from August 1996 to May 2004. METHODS: Eleven patients were treated with curative intent. Demographic data, histopathology, extent of tumor involvement, and need for adjunctive radiation or chemotherapy were determined. Local recurrence (LR), distant metastasis, overall survival (OS), and disease-free survival (DFS) rates were calculated. RESULTS: The mean age for the patient population was 62.5 (52-85) years with a male:female ratio of 8:3. Multimodality therapy including radiation or chemotherapy was used in 8 of 11 (73%) patients. Seven patients were resected using strictly an endoscopic approach, whereas four required combined endoscopic and neurosurgical resection. LR and distant metastatic rates were 20% and 0%, respectively. OS and DFS were both 91%, with mean follow-up of 31.5 (range 6-88) months. CONCLUSIONS: Endoscopic resection in combination with multimodality therapy is an effective method for curative resection of sinonasal SCC. In this preliminary study, it facilitated complete resection with acceptable LR and DFS rates.

Endoscopic transpterygoid approach to the lateral sphenoid recess: surgical approach and clinical experience.

OBJECTIVE: Pathology within a lateral recess of a widely pneumatized sphenoid sinus is difficult to access with the use of traditional open and current endoscopic surgical approaches. A new surgical procedure, the endoscopic transpterygoid approach, directly accesses this region. A clinical experience over several year with this approach is reported as well as a refined and updated description of the technique. SETTING: Tertiary care center. METHODS: Retrospective review of medical records of patients treated with the endoscopic transpterygoid approach to the lateral sphenoid recess. RESULTS: An endoscopic transpterygoid approach was performed in 9 patients, 6 to resect a middle fossa meningoencephalocele and repair the CSF leak and associated skull base defect, 2 for possible invasive fungal sinusitis, and 1 to marsupialize a symptomatic epidermoid cyst. Patients tolerated the approach well and no significant complications occurred. CONCLUSIONS AND SIGNIFICANCE: In selected cases, the endoscopic transpterygoid approach enables the otolaryngologist to meet modern demands to treat conditions in the lateral sphenoid using minimally invasive techniques that are well-tolerated by patients. The surgical approach and the initial experience described herein is presented in the hopes that it can aid fellow otolaryngologists to help patients with challenging conditions in this region of the body.

Endoscopic management of cerebrospinal fluid leak associated with the use of bone wax in skull-base surgery.

OBJECTIVE: To alert otolaryngologists to consider the possibility that bone wax may be associated with cerebrospinal fluid leaks that occur immediately after skull-base craniotomy approaches. STUDY DESIGN AND SETTING: Clinical report from surgical experience in a tertiary care setting. RESULTS: Three patients presented with brisk cerebrospinal fluid leak after craniotomy. Sinus endoscopy revealed bone wax within a small parasphenoid defect in all 3 cases. CONCLUSIONS: Bleeding from areas of the skull base adjacent to the paranasal sinuses during craniotomy can signal a small breach of the skull base. Bone wax may control bleeding from edges of transected bone but also stent the skull-base defect open, preventing fibrin deposition and spontaneous healing and closure. SIGNIFICANCE: Otolaryngologists repairing a cerebrospinal fluid leak after a skull-base craniotomy approach should consider the possibility of encountering bone wax and be able to identify it to better treat their patient.

Image-guided procedures of the skull base.

The primary factor in determining the surgical approach to skull base pathology should not be the presence or absence of IGS. The knowledge and experience of the surgeon is far more important than any technology or instrumentation. As with any computerized system, IGS is susceptible to numerous human and technical errors that can lead a surgeon astray. IGS must be used solely as a preoperative planning instrument and an intraoperative confirmatory tool. Under no circumstances should a surgeon proceed with a procedure using only information obtained from an IGS system, nor should a surgeon feel compelled to perform operations for which they have not had adequate training simply because IGS is now widely available. Continued advances in endoscopic equipment, radio-graphic techniques, and IGS systems will permit the rhinologist to continue to stretch the minimally invasive boundaries in treating skull base pathology.