Analysis of the suprabullar and retrobullar recesses for endoscopic sinus surgery.

Presently, the basic structures and spaces of the paranasal sinuses are more clearly understood by otolaryngologists than ever before. Yet, the more subtle and complex ethmoid features, especially of the ethmoidal pre-recesses and recesses, still elude many otolaryngologists. One of the most nebulous, elusive, and difficult-to-understand recesses is the sinus lateralis, or as it is more correctly called, the retrobullar and suprabullar recesses. The primary purpose of this investigation was to ascertain the prevalence of the sinus lateralis in humans. The secondary purpose was to better characterize this subtle feature of ethmoid anatomy. Human cadaver sinonasal complexes were meticulously dissected by both gross and endoscopic techniques. The hiatus semilunaris superior and sinus lateralis were present in all specimens. A separate and discrete retrobullar recess was present in 93.8%. Typically, a crestlike projection from the basal lamella to the lamina papyracea was noted within the posterior aspect of the retrobullar recess. A single, discrete, well-developed suprabullar recess was present in 70.9%, and a rudimentary suprabullar recess was present in 22.9%. In 7.2%, a single large cleft collectively excavated the retrobullar and suprabullar recess areas; separate retrobullar and suprabullar tracts were not present in this subgroup. Typically, the suprabullar recess was separate from and did not communicate with the frontal recess. The data from this investigation indicate that the separate terms retrobullar recess and suprabullar recess more accurately designate the anatomy and are recommended over the term sinus lateralis.

The bulla ethmoidalis: lamella or a true cell?

BACKGROUND: The anterior ethmoidal region, including the bulla ethmoidalis, is the most common area addressed during functional endoscopic sinus surgery. Therefore, a detailed understanding of the bulla is essential for safe and effective surgery. HYPOTHESIS: Based on a review of historical articles on sinus anatomy and review of the current understanding of sinonasal embryology, it is suggested that the ethmoidal bulla is a "lamella" structure rather than a "cell," as it is widely accepted to be. OBJECTIVE: To analyze the anatomic conformation and nature of the ethmoidal bulla. METHODS: Detailed gross anatomic sagittal dissection of 14 sinonasal complexes with special attention to the ethmoidal bulla and surrounding structures and pneumatization tracts. RESULTS: The ethmoidal bulla consisted of a distinct bony lamella in all cases. The degree of development and pneumatization was variable, ranging from a rudimentary torus to a relatively well-pneumatized "bulla"-like structure. A pneumatization tract originating from the retrobullar recess was present in all specimens. This pneumatization excavated into the lamella, creating the bulla-like appearance as viewed from the middle meatus. However, the bulla was not a discrete individual ethmoid cell as it did not have a complete or discrete posterior bony wall. Rather, the posterior wall of this pneumatization tract was formed by the basal lamella. CONCLUSION: The ethmoidal bulla lacks a distinct posterior wall and therefore is not a separate cell but rather a bony lamella with an air space behind it. From an anatomic perspective, bulla is perhaps not the best term for this structure.

Bone involvement in sinusitis: an apparent pathway for the spread of disease.

OBJECTIVES/HYPOTHESIS: To study the effects of bone involvement in experimentally induced sinusitis and the effect of involved bone on the overlying mucosa. STUDY DESIGN: Animal study. METHODS: Sinusitis was induced unilaterally with Pseudomonas aeruginosa in the maxillary sinus of 19 New Zealand white rabbits. At 6 weeks, the pathogenic organism was confirmed by culture, and a segment of the bone from the medial wall of the sinus implanted in a submucosal pocket in the opposite sinus. The rabbits were killed at predetermined time intervals up to 13 weeks from sinusitis induction, and en bloc sinus sections were decalcified and stained. RESULTS: The implanted bone reabsorbed partially or totally in all specimens. However, the study revealed clear histological evidence of bone involvement adjacent to the infected sinuses and the bony changes extended to the noninfected side in all specimens. The histological findings were identical to those seen in chronic osteomyelitis. CONCLUSIONS: This study demonstrates the ability for pseudomonal sinusitis, at least in the presence of surgical intervention, to involve bone at a distance from the site of primary infection in the absence of intervening mucosal disease. If confirmed with additional organisms and models, these findings have significant implications for the therapeutic management of chronic sinus disease.

The effect of corticosteroids in the treatment of experimental sinusitis.

Emerging evidence indicates that medically recalcitrant sinusitis may be associated with a prolonged and excessive state of inflammation rather than a simple bacterial infection. Corticosteroids have been anecdotally reported to be helpful in treating patients with sinusitis; however, there are no scientific studies documenting the safety and efficacy of corticosteroid therapy in sinusitis. To resolve the controversy over whether corticosteroids promote or inhibit the resolution of sinusitis, we present a prospective study of 80 rabbits with surgically introduced pseudomonal sinusitis that were then treated in one of four arms: control, ceftazidime, methylprednisolone, and ceftazidime with methylprednisolone. Sinus cavities were then evaluated after 5, 14, 21, and 28 days of treatment both by histologic inflammation grading and bacterial quantification. Results showed a significant decrease in bacterial loads in both the antibiotic and antibiotic with steroid arms over control animals, although no difference was seen between the two. Histologic grading showed a similar trend, although statistical significance was not obtained. Overall, this study demonstrated no clear advantage of steroids in the treatment of sinus infections using this model. At the same point, no significant reduction in the effectiveness of antibiotic therapy was seen with concurrent steroid use. A number of limitations of the animal model are noted and the need for human studies in this area is discussed.

The vomeronasal organ: an objective anatomic analysis of its prevalence.

The function and location of the vomeronasal organ in humans remains poorly understood. Indeed, there has been considerable controversy as to whether it even exists. Until now, there has been no published report of its prevalence or location as ascertained by the most widely accepted visual operative instrument in sinonasal surgery: the rigid nasal endoscope. In this study, multiple observers used the nasal endoscope to determine the prevalence and character of the vomeronasal organ in humans. We performed nasal endoscopy on 22 cadaver heads and 78 live humans; we also biopsied cadaver specimens to histologically confirm the endoscopic diagnosis. We found evidence of this organ in 13 of the 22 cadavers (59.1%) and in 22 of the 78 patients (28.2%). Many nasal surgeons are unaware of this organ and its potential physiologic significance. It is our hope that by recognizing its prevalence and location, nasal surgeons will be more likely to identify and possibly preserve this mysterious organ until its function is more clearly understood.

Experimental myospherulosis of the paranasal sinuses: a histologic rabbit study.

Myospherulosis or lipogranuloma formation is frequently iatrogenic and is caused by a petrolatum, lanolin, or paraffin-based ointment becoming trapped within tissue. Four different ointments, including the newly available Bactroban nasal, were studied in a rabbit paranasal sinus model to evaluate their proclivity to induce myospherulosis. The maxillary sinuses of 16 New Zealand white rabbits were bilaterally inoculated with Bactroban, Bactroban nasal, tetracycline, or bacitracin ointments and compared to saline controls in two rabbits. Sinus specimens were harvested at 2 and 4-week intervals and processed for histologic study. Myospherulosis formation was uniformly induced with the Bactroban nasal, bacitracin, and tetracycline ointments in 8/8, 7/8, and 8/8 sinuses, respectively. In contrast, myospherulosis was not induced in the 5/8 of the sinuses using Bactroban. The data from this investigation indicate that Bactroban nasal (paraffin vehicle) is similar to bacitracin and tetracycline ointments (petrolatum and petrolatum-lanolin vehicles) in that they all can cause myospherulosis. In contrast, Bactroban (a water-soluble, polyethylene glycol base) causes myospherulosis to a much smaller extent. Our results emphasize the differences between the two types of Bactroban preparations and provide objective data that can be evaluated by otolaryngologists who apply these ointments following nasal cavity surgery.

Endoscopically guided sinonasal cultures: a direct comparison with maxillary sinus aspirate cultures.

Sinusitis is a common medical problem that can at times be challenging to treat. Although most cases respond to empiric therapy, success is not achieved universally. If empiric therapy fails, it is important to identify the causative bacterial pathogen. Antral puncture is the traditional diagnostic method to recover and identify pathogens in sinusitis; however, it remains a painful, invasive test with potential complications. In contrast, rigid sinonasal endoscopy permits recovery of mucopus emanating from the sinus ostia with little pain and few possible complications. Endoscopy also affords important visual information that can confirm or refute a historical/clinical diagnosis of sinusitis. Although previous studies have shown poor correlation between nasal cavity swab cultures and maxillary sinus aspiration cultures, few investigations have compared endoscopically guided middle meatal cultures with cultures obtained from maxillary sinus aspiration. Thirteen patients with maxillary sinusitis in one or both sinuses underwent endoscopically guided culture of the middle meatus and maxillary sinus puncture with aspiration and culture (16 total study samples). Results from the microbiologic analysis were compared. Endoscopically guided middle meatal cultures accurately identified the predominant bacterial pathogen and correlated with the cultures from maxillary sinus aspiration in more than 90% of infections. These preliminary results suggest that endoscopically guided sinonasal cultures hold promise as a viable alternative to maxillary sinus aspiration. Endoscopically guided cultures appear to be an effective, noninvasive diagnostic tool for otolaryngologists managing sinusitis.

Interleukin-1 beta, interleukin-5, interleukin-6, interleukin-8, and tumor necrosis factor-alpha in chronic sinusitis: response to systemic corticosteroids.

Recently, the role of various cytokines in the pathogenesis of chronic rhinosinusitis has come under investigation. Various studies have reported increased levels of interleukin-3, interleukin-4, interleukin-5, interleukin-13, and granulocyte macrophage-colony stimulating factor in the sinonasal mucosa of patients with chronic rhinosinusitis. The present study investigated the levels of pro-inflammatory cytokines, including interleukin-1 beta (IL-1 beta), interleukin-5 (IL-5), interleukin-6 (IL-6) interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha), in the sinonasal mucosa of patients with chronic rhinosinusitis, and evaluated the response of these cytokines to oral corticosteroids. Chronic rhinosinusitis subjects (n = 15) and control subjects (n = 9) underwent nasal endoscopy and biopsy of the sinonasal mucosa. Chronic rhinosinusitis subjects were subsequently treated with a 10-day tapering dose of prednisone followed by a second sinonasal endoscopic exam and biopsy. Mucosal biopsy specimens were immunostained for IL-1 beta, IL-5, IL-6, IL-8, and TNF-a. In chronic rhinosinusitis subjects, mucosal levels of IL-1 beta, IL-6, IL-8, and TNF-alpha were significantly elevated when compared with control subjects, and levels of IL-5 demonstrated a strong trend toward elevation. In posttreatment chronic rhinosinusitis subjects, levels of IL-6 were significantly decreased when compared with pretreatment levels, and TNF-alpha levels demonstrated a significant trend toward reduction. These findings support the hypothesis that the inflammatory response in chronic rhinosinusitis is associated with elevated levels of pro-inflammatory cytokines, and suggest that oral corticosteroids may exert a beneficial effect by significantly reducing the levels of IL-6 and TNF-alpha.

The forgotten turbinate: the role of the superior turbinate in endoscopic sinus surgery.

The fate of the middle turbinate in endoscopic sinus surgery has been a subject of debate for some time. The superior turbinate's role, however, has been largely passed over. Past anatomic descriptions and illustrations have given surgeons the incorrect impression that this structure is well superior and out of the field of dissection. Injury to the superior turbinate may account for postoperative hyposmia. The superior turbinate also serves as a constant landmark for the sphenoethmoidal recess, and a limited resection allows the surgeon to identify and include the natural ostium of the sphenoid sinus in the sphenoidotomy. The embryology and anatomy of the superior turbinate are reviewed. An approach to the natural ostium of the sphenoid sinus from the lateral side of the middle turbinate, using the superior turbinate as a guide, is described.

Retained stenting material: an unusual cause of dacryocystorhinostomy failure.

OBJECTIVE: To highlight a troubling cause of dacryocystorhinostomy (DCR) failure and to alert ophthalmologists to the potential problems that can result when stenting material is not removed and becomes retained after DCR. DESIGN: Consecutive noncomparative case series. PARTICIPANTS: Twelve patients who underwent revision DCR from February 1994 to January 1997. INTERVENTION: Endoscopic DCR, pre- and postoperative nasal endoscopy, preoperative computerized tomography (CT), and pre- and postoperative Jones testing. RESULTS: Fourteen revision endoscopic procedures were performed on 12 patients with recurrent epiphora following DCR. Failure was due to retained stenting material in six patients, a small bony rhinostomy in three patients, excessive scar formation within the rhinostomy in two patients, and improper location of the rhinostomy in one patient. Preoperative endoscopy and CT scan each correctly identified the retained sponge or tubing in four of six patients. CONCLUSIONS: Fastening a small sponge to Silastic tubing and positioning it within the DCR site in an attempt to retard DCR stenosis can be associated with a poor outcome and should be avoided. The nasal endoscope provided excellent visualization of pathology within the lacrimal sac and was a valuable tool. Retained stenting material should be considered in patients with persistent epiphora following DCR or intubation prior to any decision to commit a patient to permanent Jones tube placement.

The role of the crista ethmoidalis in endoscopic sphenopalatine artery ligation.

Posterior epistaxis is a significant medical problem that can be challenging to treat. Endoscopic surgery could potentially reduced operative time and patient risk; however, surgeons report difficulty in endoscopically isolating the major offending artery, the sphenopalatine. These difficulties could be reduced if a recognizable anatomic structure marked the region of the artery. The study objective is to characterize the relationship of a relatively unknown anatomic structure, the crista ethmoidalis, to the sphenopalatine foramen/artery, in an effort to facilitate location of the sphenopalatine artery during endoscopic ligation. Using 22 human cadaveric sagitally sectioned heads and standard gross anatomic dissection techniques, the presence of the crista ethmoidalis was sought and recorded as well as its relative location to the sphenopalatine foramen/artery. The crista ethmoidalis was present and closely related to the sphenopalatine foramen and artery in all specimens. In 21/22 specimens, the crista was located just anterior to the sphenopalatine foramen, whereas in one specimen it was located 3 mm directly inferior to the foramen. Our investigation indicates that the crista ethmoidalis is a helpful and reliable landmark for endoscopically locating the sphenopalatine artery and foramen. Using this landmark, the initial problems reported with endoscopic ligation, i.e., locating the foramen and artery, should be greatly reduced. We offer our observations regarding the crista ethmoidalis to assist endoscopic surgeons in the care of their difficult epistaxis patients.

Use of the superior meatus and superior turbinate in the endoscopic approach to the sphenoid sinus.

Endoscopic surgery of the posterior ethmoid and sphenoid sinuses can present the operator with a considerable challenge. Although endoscopic training and physician experience have increased significantly in the past decade, surgical complications such as optic nerve trauma and cerebrospinal fluid leak still occur. Surgeons reporting such complications cite a lack of orientation within the dissection field as a primary cause. Because endoscopic sinus surgery is now being performed more routinely, surgical strategies designed to reduce the risk of complications are more important than ever. An anatomic landmark that could reliably orient the dissection within the posterior ethmoids and guide the surgeon to the sphenoid sinus could reduce the possibility of such adverse outcomes. In our experience identification of the superior meatus and superior turbinate provides a reliable landmark within the dissection field that can ensure surgical orientation to the operator. This technique allows safe, reliable dissection of the posterior ethmoids and an efficient approach to the sphenoid sinus, especially in patients undergoing revision surgery. In this article our technique for the identification and definition of the superior meatus and superior turbinate is presented, and the advantages of using this landmark in sinus surgery are discussed. In our experience identification of the superior meatus, superior turbinate, posterior skull base, and medial orbital wall defines a parallelogram-shaped box, which delineates the sphenoid face. This box provides the necessary orientation to guide the surgeon's entrance into the sphenoid sinus through the posterior ethmoid sinus (as Messerklinger described). Techniques for identifying the superior turbinate and meatus and for entering the sphenoid are detailed.

The reliability of computerized tomographic detection of the Onodi (Sphenoethmoid) cell.

Optic nerve injury is a devastating potential complication of endoscopic sinus surgery. Anatomic variations of the posterior ethmoid sinus are certainly contributing factors. In the most well described posterior ethmoid anatomical variant, the sphenoethmoid or Onodi cell, the optic nerve is placed at risk during sinus surgery. Improving preoperative and intraoperative identification of the sphenoethmoid (Onodi) cell could decrease the risk of optic nerve injury. The purpose of this investigation was to assess the reliability of computerized tomography (CT) in detecting the sphenoethmoid (Onodi) cell, and further our understanding of this clinically relevant anatomic variant. A total of 41 sinonasal complexes from 21 human adult cadaveric heads were studied with a standard coronal and axial plane CT, and subsequent endoscopic dissection. The prevalence of the sphenoethmoid (Onodi) cell was determined by CT and endoscopic dissection, as were other anatomic characteristics of the posterior ethmoid anatomy. In our study, CT identified a sphenoethmoid (Onodi) cell in 3/41 (7%) of the sphenoethmoid complexes. However, anatomic dissection identified a sphenoethmoid (Onodi) cell in 16/41 (39%) complexes. Coronal orientation of the anterior sphenoid wall was never associated with a sphenoethmoid (Onodi) cell. Conversely, oblique or horizontal orientations were present in all cases of sphenoethmoid (Onodi) cells. Current CT scanning protocols for the paranasal sinuses did not reliably detect the Onodi cell. Endoscopic dissection indicates that the sphenoethmoid (Onodi) cell is a more frequent anatomic variant than previously appreciated. Awareness of anterior sphenoid wall orientation may assist surgeons in identifying the Onodi cell, thereby reducing the risk of optic nerve trauma.

Gram negative sinusitis: a bacteriologic and histologic study in rabbits.

Recent investigations of chronic sinusitis that is "recalcitrant" to traditional medical and surgical therapy indicate that gram negative bacteria are frequently involved, most commonly Pseudomonas aeruginosa. Analysis of infection-induced histopathologic changes in the underlying sinus mucosa may provide important insight into the recalcitrant nature of these infections. Therefore, the aim of this investigation is to experimentally induce sinus infection in the rabbit with Pseudomonas aeruginosa, a bacterium commonly associated with "recalcitrant sinusitis," and evaluate the histopathologic findings. A unilateral maxillary sinusitis was induced in 33 New Zealand white rabbits. Histologic analysis at 4, 14, 21, and 28 days revealed a moderate inflammation that persisted throughout the study period. Initial changes included edema, loss of submucosal glands, and ulceration. Fibroplasia and bone remodeling were evident throughout the study. Epithelial plaque formation occurred early in the infection, whereas goblet cell formation was a later change. Experimental sinusitis induced by Pseudomonas aeruginosa causes an intense transmucosal injury. The histopathologic injury and response to Pseudomonas aeruginosa appears to be more intense than that noted on previous investigations of experimental sinusitis using other bacteria. The significant histopathologic changes noted could explain the recalcitrant nature of gram negative sinusitis observed clinically in patients.

A comparison of morphological effects on the rabbit nasal and sinus mucosa after surgical denervation and topical capsaicin application.

In order to study morphological effects on the nasal and sinus mucosa, New Zealand White rabbits underwent either unselective, regional sectioning of sensory and parasympathetic nerve branches or topical treatment of the mucosa with capsaicin. Ten days after treatment, mucosal specimens were analyzed by light and electron microscopy. Immunohistochemistry was used to evaluate neuropeptides present, in particular substance P, calcitonin gene-related peptide, vasoactive intestinal peptide and neuropeptide Y. In surgically denervated rabbits, mucosal glands were found to be enlarged and contained an increased number of zymogen granules having a bipartite substructure. Topical capsaicin application caused localized epithelial changes in the sinus mucosa and maxilloturbinal region of the nose, including clotting of cilia and an increased number of goblet cells. Reduced amounts of all neuropeptides investigated were found in the surgically denervated animals, while topical capsaicin treatment had only marginal effects on the mucosal neuropeptide content. The morphological changes observed after surgical denervation suggest an imbalance between neural stimulation and secretory capacity of the mucosal glands. These findings could explain the difference in clinical effect noted between sectioning of the vidian nerve and topical treatment with capsaicin in patients with perennial rhinitis.

Sinus and facial growth after pediatric endoscopic sinus surgery.

OBJECTIVE: To determine the effect of functional endoscopic sinus surgery (FESS) on facial skeletal growth in children. DESIGN: Prospective randomized controlled animal study; retrospective histopathologic study of pediatric FESS specimens. SETTING: Academic tertiary referral medical center. PARTICIPANTS: Eight newly weaned piglets; uncinate and ethmoid bone of FESS specimens from 84 children. INTERVENTIONS: The piglets underwent unilateral FESS. When they had developed to nearly adult size, computed tomography was used to compare facial and sinus development between the surgical and nonsurgical sides. The paranasal sinus contents from children were histologically examined to analyze bone types with respect to patient age. OUTCOME MEASURES: Sinus development and facial skeletal growth after FESS in piglets; histologic maturity of sinus bone in children. RESULTS: Facial growth in piglets was significantly reduced on the side treated by FESS. When compared with the side that did not undergo the operation, growth reached only 57% in the maxillary sinus and 65% in the ethmoid region. Children younger than 9 years had woven (immature) bone; children 9 years and older had predominantly lamellar (mature) bone. CONCLUSIONS: This preliminary study shows that even limited surgery in the anterior ethmoid region can affect sinus and facial growth in the piglet. Review of corresponding human histologic specimens suggests that further investigation is warranted to rule out the possibility of facial and sinus growth disturbance after this surgery in children.

Lacrimal drainage system injury in functional endoscopic sinus surgery. Incidence, analysis, and prevention.

Injury to the lacrimal drainage system with resultant epiphora is a complication of functional endoscopic sinus surgery. A study of 24 patients was conducted to determine the incidence and significance of lacrimal drainage system injuries during functional endoscopic sinus surgery. Intraoperative testing demonstrated seven occult injuries (15%) in 46 endoscopic procedures. Postoperative testing demonstrated diversion of lacrimal drainage into the middle meatus in two patients and spontaneous healing of the injured lacrimal drainage system with restoration of normal drainage in three of the patients available for follow-up testing. In no patient did epiphora develop. It is concluded that the nasolacrimal drainage system is in close proximity to the dissection cavity during functional endoscopic sinus surgery and, hence, is at risk for inadvertent injury. Occult damage to the nasolacrimal drainage system would appear to be a common event during functional endoscopic sinus surgery; however, the complication of postoperative epiphora is rare.