Pitfalls in computed tomography of the paranasal sinuses.

The advent of functional endoscopic sinus surgery has created the need for high-quality radiographic images to assess the paranasal sinuses, document the detailed anatomy of the lateral nasal wall and provide an anatomical map allowing safe functional endoscopic sinus surgery. This paper will discuss our experience of 410 paranasal sinus coronal CT scans performed by the technique described by Zinreich prior to consideration of functional endoscopic sinus surgery. The main indications for the scans were acute recurrent sinusitis, abnormal diagnostic nasal endoscopic examination and persistent facial pain. We will consider both the radiological and surgical difficulties that have arisen from the use of this technique and highlight some of the methods to avoid these difficulties. Claustrophobia and limitation of neck movements, particularly in patients over the age of 60, were the most common factors leading to suboptimal scans. Ensuring that the patient was in a symptom-free interval, the differential diagnosis of the opacified paranasal sinus and patients with gross polypoid disease created the most difficulty in interpretation. The anatomical assessment of the frontal recess and the identification of the optic nerve posterolateral to the posterior ethmoidal cell have created the greatest anatomical difficulty.     

Virtual Endoscopy of the Paranasal Sinuses Using Perspective Volume Rendered Helical Sinus Computed Tomography

Our goal was to use three-dimensional information obtained from helical computed tomographic (CT) data to explore and evaluate the nasal cavity, nasopharynx, and paranasal sinuses by simulated virtual endoscopy (VE). This was done by utilizing a new image reconstruction method known as perspective volume rendering (PVR). Thin-section helical CT of the nasal cavity, nasopharynx, and paranasal sinuses was performed on a conventional CT scanner. The data were transferred to a workstation to create views similar to those seen with endoscopy. Additional views not normally accessible by conventional endoscopy were generated. Key perspectives were selected, and a video “flight” model was choreographed and synthesized through the nasal cavity and sinuses based on the CT data. VE allows evaluation of the nasal cavity, nasopharynx, and paranasal sinuses with appreciation of the relationships of these spatially complex structures. In addition, this technique allows structural visualization with unconventional angles, perspectives, and locations not conventionally accessible. Although biopsies, cultures, and lavages routinely done with endoscopy cannot be performed with VE, this technique holds promise for improving the diagnostic evaluation of the nasal cavity, the nasopharynx, and the paranasal sinuses. The unconventional visual perspectives and very low morbidity may complement many applications of simple diagnostic endoscopy.     

Microscope and endoscope-assisted surgery of inflammatory diseases of the paranasal sinuses. Value of the Messerklinger infundibulotomy

Insights into the importance of the infundibulum of the anterior ethmoid bone in the etiology and pathogenesis of chronic paranasal sinusitis, based above all on the studies of Messerklinger, have resulted in a fundamental change in our concept of therapy: the main objective of any treatment must be the restoration of ventilation and drainage of the paranasal sinuses in the region of the semilunar hiatus. Its function in the healing of paranasal sinus diseases parallels the significance of the Eustachian tube for the healing of inflammatory lesions of the middle ear. In many cases, the objective is attained by infundibulotomy, using Messerklinger's technique. Our technique differs from that described by Messerklinger and Wigand: we use the surgical microscope and a self-retaining nasal speculum. It is thus possible to operate with both hands, as in microsurgery of the ear and the larynx. Moreover, the operations can be taught and learned via an observation tube. Since the introduction of this technique which can be extended at any time to complete endonasal surgery of the maxillary, ethmoid and sphenoid sinuses, extranasal operations on the paranasal sinuses have become exceedingly rare. The results have been checked in a newly established paranasal sinus clinic.     

鼻内镜在诊治鼻腔鼻窦真菌病中的应用

目的：评价鼻内镜技术在鼻腔鼻窦真菌病的诊断和治疗中的应用价值。方法：对54例非变态反应性真菌性鼻窦炎患者应鼻内镜技术诊断与治疗的经验进行总结。结果：全部患者均获治愈，随访1-5年未见复发。结论：在本病的诊断与治疗中，应用鼻内镜技术可减轻患者的侵损性操作，并缩短诊治时间，避免或减少复发。鼻内镜技是诊断治疗鼻腔鼻窦真菌病较为理想的方法。     

The management of sinonasal inverted papilloma: our experience

The inverted papilloma of the nose and paranasal sinuses is a controversial disease. It invades surrounded structures, shows a high recurrence rate after surgical excision and may coexist with squamous cell carcinoma. The use of the optimal surgical approach and technique is of the utmost importance, as it is related to the possibility of recurrence. In cases of tumors of limited size a conservative local excision is sufficient, while, in larger tumors filling the nasal cavity and the paranasal sinuses a more aggressive strategy is needed, such as a medial maxillectomy after lateral rhinotomy. In this paper we present our experience from treating 42 sinonasal inverted papillomas, using a surgical technique which is based on the conservation of as much part of the healthy lateral nasal wall as possible. This modified medial maxillectomy allows us to create a limited in size and normally functioning nasal cavity, thus minimizing the disadvantages of the classical medial maxillectomy without jeopardizing the safety of the operation.     

Nasal and paranasal sinus carcinoma: how can we continue to make progress?

PURPOSE OF REVIEW: New developments in the nasal and paranasal sinus cancers are reviewed. RECENT FINDINGS: In addition to woodworking, several risk factors for nasal and paranasal sinus cancers have been identified, most notably smoking. Progress in the differential diagnosis of small round cell nasal and paranasal sinus cancers allows the precise diagnosis of esthesioneuroblastoma. Despite recent improvements, T staging for ethmoid and nasal cavity needs refinement. An association of surgery and radiation therapy remains the best treatment modality. Major developments include endoscopic resection of nasal and paranasal sinus cancers, high-precision radiotherapy techniques such as intensity-modulated radiotherapy, and proton-beam radiotherapy. There is probably no role for chemotherapy in esthesioneuroblastoma. Although chemotherapy is important for aggressive neoplasms, its generalized use for nasal and paranasal sinus cancers awaits the application/development of newer drugs. These drugs might be applied locally since the majority of recurrences remain local. SUMMARY: Progress in the treatment of nasal and paranasal sinus cancers could be achieved through better prevention and the developments of more selective treatments such as endoscopic resection, high-precision radiotherapy, and new chemotherapy drugs.     

Nasal polyps. Definitions and development of pathogenesis theory

This paper presents definitions and types of classifications of nasal polyps. The precise pathogenesis of nasal polyps is not known, although there are several important factors: chronic and recurrent infection of nasal mucose, abnormal vasomotor response, airflow blockade of the middle meatus and ostia of the paranasal sinuses. Since 1843 several pathogenic theories have been introduced.     

TNF-alpha and endotoxin increase hypoxia-induced VEGF production by cultured human nasal fibroblasts in synergistic fashion

OBJECTIVE: Vascular endothelial growth factor (VEGF) promotes angiogenesis and is associated with the invasion and metastasis of malignant tumors. It enhances vascular permeability and is expressed in inflammatory nasal as well as middle-ear mucosa. As the mechanism of VEGF induction during chronic inflammation, such as chronic paranasal sinusitis (CPS) remains to be clarified, we studied the factors regulating the production of VEGF in cultured human nasal fibroblasts and discussed the role of VEGF in the pathogenesis of CPS. METHODS: We used ELISA to quantify VEGF levels in paranasal sinus effusions, nasal secretions, and serum from patients with CPS. In addition, we cultured human nasal fibroblasts isolated from nasal polyps of CPS patients and studied the effects of hypoxia, TNF-alpha, and endotoxin on their production of VEGF using ELISA and PCR. RESULTS: The VEGF concentration was significantly higher in paranasal sinus effusions than in nasal secretions and serum. Nasal fibroblasts produced high levels of VEGF, when cultured under hypoxic condition and this production was remarkably enhanced in the presence of TNF-alpha or endotoxin. CONCLUSION: VEGF is locally produced in paranasal sinuses as well as nasal mucosa and its production is increased in patients with CPS. Hypoxia is associated with the production of VEGF by nasal fibroblasts and TNF-alpha and endotoxin may act synergistically to enhance VEGF production in paranasal sinuses under hypoxic condition.     

鼻腔鼻窦恶性肿瘤中BRMS1基因蛋白表达的研究

目的:以鼻腔鼻窦恶性肿瘤为研究对象,探讨肿瘤转移抑制基因BRMS1在其发生、发展和转移中的作用及临床意义。方法:采用免疫组织化学SP法分别检测53例鼻腔鼻窦恶性肿瘤组织、24例鼻息肉组织及10例正常组织中BRMS1基因蛋白的表达,分析在不同临床病理指标下BRMS1蛋白表达的情况。结果:BRMS1蛋白在正常组织中的阳性表达率(90.0%)及息肉组织中的阳性表达率(79.2%)均显著高于癌组织中的阳性表达率(39.6%),差异均有统计学意义(均P<0.01)。癌组织中BRMS1蛋白阳性表达率与临床分期和淋巴结转移有关,与病理分级无关。结论:鼻腔鼻窦恶性肿瘤的发生、发展和转移与BRMS1基因的失活密切相关。     

鼻腔鼻窦非霍奇金淋巴瘤的CT表现

目的：探讨鼻腔鼻窦非霍奇金淋巴瘤（ＣＨＬ）的ＣＴ影像学特征,方法：对９例经病检确诊为鼻腔鼻窦ＮＨＬ患者的ＣＴ片进行回顾性分析。结果;原发于鼻腔鼻窦的ＮＨＬ在临床上有着典型的恶性特征,但在ＣＴ影像上所表现的骨质破坏,类似于良性病变的骨改建、骨膨胀性改变,而非其他恶性肿瘤那样表现为侵入性骨质破坏;其在鼻腔内形成均匀软组织密度影,常累及下鼻道、下鼻甲;并伴有鼻中隔前份粘膜对称性增厚;结论：原发于鼻腔鼻窦     

Functional endoscopic ethmoid bone revision in inflammatory paranasal sinus diseases in childhood]

A total of 57 children aged between 5 and 15 years underwent endoscopic ethmoid surgery for recurrent acute or chronic rhinogenic sinusitis, chronic sinusitis associated with bronchial asthma or chronic bronchitis, early rhinogenous orbital complications and paranasal sinus disease associated with mucoviscidosis. The indications for surgical intervention are based on symptoms, the findings on nasal endoscopy and a CT scan of the paranasal sinuses in the coronal plane. The preoperative examination shows that in childhood there are endoscopically detectable anatomical variations of the ethmoid bone (pneumatised middle nasal concha, reversed curvature of the middle turbinate and contact between the uncinate process and the turbinate) that create the conditions for the development of inflammatory paranasal sinus diseases. Careful elimination of these obstructions can accomplish complete cure of the inflammation, and early orbital complications can be treated effectively by combination of surgery with infusion of antibiotics. All surgery was performed under endotracheal anaesthesia using the endoscopic technique described by Messerklinger. The follow-up period was between 6 and 18 months. With the exception of children suffering from mucoviscidosis, cure of the paranasal sinus disease and rhinomanometrically demonstrable improvement of the nasal breathing was achieved in all cases. On the basis of our results a conservative endoscopic approach is recommended as an effective surgical method for the treatment of paranasal sinus disease in childhood.     

Endoscopic transethmosphenoidal approach for pituitary tumors with image guidance.

The advantages of endoscopic transethmosphenoidal surgery for pituitary tumors using a navigation system were reported. The surgical technique was as follows. First, sphenoidal sinuses were opened via the bilateral ethmoidal sinuses and the olfactory clefts. Then the septum of the sphenoidal sinuses was resected. Next, an endoscope was inserted via the left nasal cavity and fixed in place. The tumor was then removed via the right nasal cavity. Our approach for pituitary tumors provided sufficient working space and permitted the surgeon to carry out the procedure using both hands. In addition, use of the InstaTrak System made it possible to recognize the orientation of the surgical field in the sella turcica. Thus, the tumor could be resected more easily and safely. It is concluded that this approach will be particularly useful for patients with narrow nasal cavities or poor development of the paranasal sinuses.     

Hyperaeration of the frontal sinus

The nasal cavity and paranasal sinuses constitute an anatomical and functional unit. Paranasal sinuses communicate with the nasal cavities, which are covered by the same mucosa, via small openings and narrow ducts that allow both aeration and sinus drainage. Anatomical variations of the paranasal sinuses and nasal cavity are important in sinus diseases. Computerized tomography (CT) plays a critical role in evaluation of the patients with paranasal sinus pathology and variations. A 38-year-old man admitted to our clinic with headache and postnasal dripping for 1 year. His paranasal CT scanning revealed that there is hyperaeration of the frontal sinus which is in continuity with the sphenoid sinus. Hyperaeration of the sinuses may be kept in mind in a patient complaining of headache.     

Semi-automatic segmentation of computed tomographic images in volumetric estimation of nasal airway

The objective of this study was to determine nasal cavity volumes and cross-sectional profiles from segmented coronal high-resolution computed tomography (HRCT) images. Pathological mucosal changes and congenital sinonasal variants were quantitated and three-dimensional (3D) images for determining sinonasal airway diseases evaluated by using the new semiautomatic segmentation software, Anatomatic. Anterior to posterior cross-sectional profiles of the sinonasal airway were obtained from acoustic rhinometry and segmented coronal HRCT images and compared in five patients having complaints of nasal obstruction and chronic sinusitis. Results showed that accurate volumes of air spaces in the nasal cavity and paranasal sinuses were obtained. When compared, the cross-sectional profiles of the nasal cavities obtained from acoustic rhinometry and the segmentation technique were similar in the anterior portion, but differed in the posterior portion. The results obtained by coronal HRCT and segmentation were more reliable than those produced with acoustic rhinometry. 3D images acquired from segmented images were found to help make a good pre-operative assessment of the whole sinonasal compartment. Segmentation and volumetric analysis using the Anatomatic technique also proved to be well suited to the evaluation of the nasal cavity and paranasal sinus geometry in patients with sinonasal diseases. Received: 5 March 1998 / Accepted: 9 June 1998     

Magnetic resonance imaging of the paranasal sinuses: incidental abnormalities and their relationship to patient symptoms.

OBJECTIVES: Magnetic resonance imaging (MRI) is able to demonstrate a wide range of abnormalities in the paranasal sinuses, which are often reported as incidental findings on scans performed for indications other than the evaluation of paranasal sinus pathology. However, the clinical significance of these findings remains undefined. We present a prospective study that determines the prevalence of abnormalities in the paranasal sinuses in a population undergoing MRI scans for suspected intracranial disease. These findings are correlated with clinical data pertaining to nasal and sinus symptoms. STUDY DESIGN: Prospective, cross-sectional study. METHODS: Patients undergoing MRI scans for suspected intracranial pathology were asked to complete a questionnaire pertaining to symptoms of nasal/sinus pathology. The T2-weighted scans of 86 patients (mean age = 51 years) were then reviewed for evidence of paranasal sinus pathology using a standardized method for evaluation and reporting of results. These results were then correlated with those obtained from the patient questionnaire. RESULTS: Radiologic abnormalities were found in the paranasal sinuses of 33 (38%) patients. Abnormalities were most commonly seen in the ethmoid sinuses (44.8%) followed by the maxillary (38%), sphenoid (14%), and frontal (3%) sinuses. Analysis of the clinical data revealed no significant relationship between the presence of clinical symptoms of nasal and sinus pathology and abnormalities on MRI scan. CONCLUSION: The assessment of inflammatory sinus pathology remains controversial. Based on the results of this study, incidental abnormalities of the paranasal sinuses detected on MRI scan do not appear to be related to clinical symptoms.     

A transfacial approach to the nasal-paranasal cavities and anterior skull base

Large lesions of the nasal and paranasal cavities present a particularly difficult problem of surgical approach. The direct transnasal, Denker's, Weber-Fergusson, lateral rhinotomy, and facial degloving approaches have all been used with varying degrees of success. Nevertheless, these approaches fail to provide adequate exposure of the midfacial and interorbital spaces. In 1979, we developed a method called the transfacial approach in which two large midfacial flaps, one containing the entire external nose, are raised, exposing the maxillae, both medial orbital walls, and the nasal and paranasal cavities. Through this panoramic approach, one can easily expose the anterior skull base to the clivus and operate on this area under direct visual and manual control. The technique of this approach is described and our experience with 16 patients in whom it was applied is reviewed.     

Sublabial rhinotomy with septal transfixion as an approach to the nasal fossa, paranasal sinuses and nasopharynx

A sublabial incision with septal transfixion and mid-face degloving is described as an approach to the nasal cavity, paranasal sinuses and nasopharynx. A brief history of the development of the technique is given. The results of nine cases are presented. These cases have had good tumour clearance, excellent cosmetic results and the minimum of complications. The sublabial approach is most useful in children and women, particularly those with intermediate grade tumours. The advantages of the approach compared to the lateral rhinotomy incision include: superior access to the floor of the nose, inferior turbinate and anterior nasal septum; access to both sides of the nasal septum and the absence of a facial scar. The limitations of the sublabial technique are the poor access to frontal sinus and the cribriform plate.     

The role of fibrinolytic enzymes in inflammation and paranasal mucous membrane

The distribution and role of tissue plasminogen activator (TA) and proactivator (PA) in various diseases of the nasal and paranasal cavity were investigated. The stronger the inflammatory and proliferative response of the paranasal mucous membrane, the weaker was the fibrinolytic activity of TA. The fibrinolytic activity of PA tended to be stronger than TA activity. It is considered that PA may play an important role in inflammatory enlargement and proliferation of the paranasal mucous membrane, but does not play an important role in carcinogenic enlargement and proliferation of the nasal and paranasal mucous membrane.     

Primary chordoma of the lateral nasal wall: case report and review

Chordomas are malignant, nonepithelial neoplasms derived from notochordal tissue. A primary chordoma of the nasal cavities and paranasal sinuses is extremely rare compared with clival chordomas, which often present as nasal masses after spreading anteriorly. Only a few cases of primary chordoma of the nasal cavities and paranasal sinuses have been reported in the literature. We report a case of a primary chordoma of the lateral nasal wall. Pathologic diagnosis was obtained using an intranasal endoscopic excision. As in our patient, a primary chordoma of the nasal cavity or paranasal sinuses may present with symptoms related to mechanical obstruction secondary to the tumor mass. We summarize our case in the context of the other reported cases, and we discuss treatment options, natural history, and prognosis.     

Endoscopic sinus surgery for benign and malignant nasal and sinus neoplasm

PURPOSE OF REVIEW: Endoscopic sinus surgery has become widely accepted as the standard of treatment for chronic inflammatory diseases of the paranasal sinuses unresponsive to medical treatment. With increased skill with endoscopic surgical technique, advanced technologies such as intraoperative imaging systems, and a better understanding of the complex anatomy of the paranasal sinuses and surrounding vital structures, many otolaryngologists have increasingly applied their expertise in endoscopic sinus surgery to the resection of nasal and sinus neoplasms. The following represents a review of the recent literature on the latest trends regarding endoscopic resection of nasal and paranasal sinus neoplasms. RECENT FINDINGS: There has been an increasing popularity in the removal of nasal and paranasal sinus neoplasms through an endoscopic approach. In the recent literature, emphasis has been on the endoscopic surgery of benign tumors, especially inverted papilloma and nasopharyngeal angiofibroma. Other benign neoplasms have also been reported, but only in small case reports. There have been a few recent reports supporting endoscopic removal of malignant neoplasms as well. However, the follow-up is too short and study groups too small to make definitive conclusions. SUMMARY: In the hand of experienced and skilled surgeons, complete endoscopic removal is attainable in most cases. Especially for the more common benign neoplasms, such as inverted papilloma and early stage angiofibroma. En bloc resection is not necessary to achieve oncologic cure. However, several factors have to be considered before selection of this surgical approach. Large tumor size, intracranial or orbital extension, and extensive frontal or infratemporal fossa involvement are relative, but not absolute limitations.