Endoscopic Management of Ethmoidal Schwannoma: A Case Report

Schwannomas of sinonasal origin are rare tumours with an incidence as low as 4% and may present with a wide range of clinical features. Due to non-specific endoscopic and radiological findings, diagnosis becomes difficult. We present a case of an ethmoidal schwannoma with nasal and nasopharyngeal extension in an elderly female patient who had a slow course of the long-standing disease. Her main complaints were nasal obstruction, nasal discharge, mouth breathing, snoring and recurrent nasal bleed. Nasal endoscopy showed a pale, firm, polypoidal mass with dilated vessels on the surface which bled on probing. It was a non-enhancing sinonasal mass with scalloping of adjacent paranasal sinuses and erosion of posterior nasal septum on contrast-enhanced computed tomography. Endoscopic excision of the mass was done in toto and histopathology report confirmed it as schwannoma. Long standing sinonasal masses especially in the elderly age group with an indolent medical history should arise suspicion of benign neoplasm especially schwannomas due to their high rate of incidence amongst benign sinonasal neoplasms.

A Rare Instance of Pterygopalatine Fossa Tumor With Hearing Loss as the Main Complaint

Pterygopalatine schwannomas are rare tumors which usually cause the symptoms of the traffic area by the tumors in the pterygopalatine fossa which is difficult to resection. This paper presents 1 rare case of pterygopalatine fossa tumor with hearing loss as the main complaint treated by total resection through the endoscopic endonasal approach.

Infra-Temporal and Pterygo-Palatine Fossae Tumors: A Frontier in Endoscopic Endonasal Surgery—Description of the Surgical Anatomy of the Approach and Report of Illustrative Cases

Infratemporal and pterygopalatine fossae (ITF and PPF) represent two complex paramedian skull base areas, which can be defined as jewelry boxes, containing a large number of neurovascular and osteomuscular structures of primary importance. They are in close communication with many craniofacial areas, such as nasal/paranasal sinuses, orbit, middle cranial fossa, and oral cavities. Therefore, they can be involved by tumoral, infective or inflammatory lesions spreading from these spaces. Moreover, they can be the primary site of the development of some primitive tumors. For the deep-seated location of ITF and PPF lesions and their close relationship with the surrounding functional neuro-vascular structures, their surgery represents a challenge. In the last decades, the introduction of the endoscope in skull base surgery has favored the development of an innovative anterior endonasal approach for ITF and PPF tumors: the transmaxillary-pterygoid, which gives a direct and straightforward route for these areas. It has demonstrated that it is effective and safe for the treatment of a large number of benign and malignant neoplasms, located in these fossae, avoiding extensive bone drilling, soft tissue demolition, possibly unaesthetic scars, and reducing the risk of neurological deficits. However, some limits, especially for vascular tumors or lesions with lateral extension, are still present. Based on the experience of our multidisciplinary team, we present our operative technique, surgical indications, and pre- and post-operative management protocol for patients with ITF and PPF tumors.

Pterygopalatine fossa schwannoma-case report and literature review

INTRODUCTION

Schwannomas are well-differentiated, benign tumours that originate from the Schwann cells of nerve sheaths. They constitute 25-45% of all the head and neck tumours and can cause significant morbidity depending on the site of origin. The pterygopalatine fossa is the rarest site of involvement, with only a few cases reported in the literature.

CASE PRESENTATION

This is the case of a 46-year-old male who presented with a twelve [12] month history of left-sided facial pain and progressive swelling. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large soft tissue lesion located in the left pterygopalatine fossa (PPF). Surgical management is presented, and technical details of the repair are discussed. At one year follow-up, there were no signs of recurrence, and the cosmetic outcome was satisfactory.

DISCUSSION

This case is one of a handful of reported cases of PPF schwannomas in the English literature. Although a significant percentage of schwannomas arise in the head and neck region, the pterygopalatine fossa is the rarest site of involvement. Due to its clinically inaccessible location and complex connections, the pterygopalatine fossa can act as a natural conduit for the spread of inflammatory and neoplastic diseases in the head and neck.

CONCLUSION

Currently, the endoscopic endonasal approach (EEA) is preferred due to its safety and good oncologic outcome. There is also decreased morbidity as it is minimally invasive. Furthermore, surgeons embarking on the EEA should be equipped with an image guidance system and be trained in advanced endoscopic techniques. However, the open approach remains a reliable and proven surgical method to treat large tumours located within this intricate and inaccessible area.

Endoscopic endonasal treatment of maxillary nerve (V2) painful neuropathy: cadaveric study with clinical correlation

BACKGROUND

Surgical access to the second (V2, maxillary) and third (V3, mandibular) branches of the trigeminal nerve (V) has been classically through a transoral approach. Increasing expertise with endoscopic anatomy has achieved less invasive, more efficient access to skull base structures. The authors present a surgical technique using an endoscopic endonasal approach for the treatment of painful V2 neuropathy.

METHODS

Endoscopic endonasal dissections using a transmaxillary approach were performed in four formalin-fixed cadaver heads to expose the V2 branch of the trigeminal nerve. Relevant surgical anatomy was evaluated and anatomic parameters for neurectomy were identified.

RESULTS

Endoscopic endonasal transmaxillary approaches completed bilaterally to the pterygopalatine and pterygomaxillary fossae exposed the V2 branch where it emerged from the foramen rotundum. The anatomy defined for the location of neurectomy was determined to be the point where V2 emerged from the foramen rotundum into the pterygopalatine fossa. The technique was then performed in 3 patients with intractable painful V2 neuropathy.

CONCLUSIONS

In our cadaveric study and clinical cases, the endoscopic endonasal approach to the pterygopalatine fossa achieved effective exposure and treatment of isolated V2 painful neuropathy. Important surgical steps to visualize the maxillary nerve and its branches and key landmarks of the pterygopalatine fossa are discussed. This minimally invasive approach appears to be a valid alternative for select patients with painful V2 trigeminal neuropathy.

Endoscopic Two-port Technique for Infratemporal Fossa Tumors: Using Prelacrimal Medial Maxillectomy and Caldwell-Luc Approach

BACKGROUND

Endoscopic endonasal approach to infratemporal fossa (ITF) had gained popularity. However, the inferior turbinate and/or lacrimal duct are often removed when performing endoscopic medial maxillectomy for ITF approach and there were potential risk of empty nose syndrome or epiphora. Although endoscopic prelacrimal recess approach (EPRA) had been introduced to avoid these complications, there were some limitations associated with surgical freedom. The objective was to report the two-port endoscopic technique using both prelacrimal recess and antral window as a means to preserve inferior turbinate and lacrimal duct while facilitating instrument availability during ITF tumor resection.

METHODS

We retrospectively reviewed three patients between September 2016 and May 2018 who were treated with this modified two port technique for ITF tumors.

RESULTS

There was one case of trigeminal schwannoma originating in the mandibular nerve, one recurrent meningioma, and one paraganglioma. This two-port technique was not initially scheduled in these three cases but decided during surgery because tumors were extensively attached to surrounding muscles and have profuse bleeding. After tumor resection, sinonasal anatomy such as inferior turbinate or lacrimal duct was well preserved.

CONCLUSIONS

We propose a hybrid endoscopic surgical procedure for ITF tumors using both EPRA and transantral window. It allows the surgeons to have an advantage of utilizing an adequate working space by bimanual technique through different two ports while preserving normal sinonasal structures.

Endoscopic endonasal approach to primitive Meckel's cave tumors: a clinical series

INTRODUCTION

Recently, an alternative endoscopic endonasal approach to Meckel's cave (MC) tumors has been proposed. To date, few studies have evaluated the results of this route. The aim of our study was to evaluate long-term surgical and clinical outcome associated with this technique in a cohort of patients with intrinsic MC tumors.

METHODS

All patients with MC tumors treated at out institution by endoscopic endonasal approach (EEA) between 2002 and 2016 were included. Patients underwent brain MRI, CT angiography, and neurological evaluation before surgery. Complications were considered based on the surgical records. All examinations were repeated after 3 and 12 months, then annually. The median follow-up was of 44.1 months (range 16-210).

RESULTS

The series included 8 patients (4 F): 5 neuromas, 1 meningioma, 1 chondrosarcoma, and 1 epidermoid cyst. The median age at treatment was 54.5 years (range 21-70). Three tumors presented with a posterior fossa extension. Radical removal of the MC portion of the tumor was achieved in 7 out of 8 cases. Two patients developed a permanent and transitory deficit of the sixth cranial nerve, respectively. No tumor recurrence was observed at follow-up.

CONCLUSION

In this preliminary series, the EEA appeared an effective and safe approach to MC tumors. The technique could be advantageous to treat tumors located in the antero-medial aspects of MC displacing the trigeminal structures posteriorly and laterally. A favorable index of an adequate working space for this approach is represented by the ICA medialization, while tumor extension to the posterior fossa represents the main limitation to radical removal of this route.

Endoscopic Treatment of Benign Tumors of the Nose and Paranasal Sinuses: A Report of 33 Cases

Background

The endoscopic approach can be used successfully for the treatment of benign tumors such as fibroosseous and vascular lesions, pleomorphic adenoma, glioma, meningioma, and schwannoma.

Methods

Thirty-three patients diagnosed with benign tumors of the nasal cavity and paranasal sinuses and treated using an endoscopic approach were reviewed retrospectively. The endoscopic approach was simple in 28 cases and associated with an external approach in 5 cases (because of an intracranial extension of the tumor in four patients and its location at the level of the anterior wall of the frontal sinus in the last case).

Results

The resection of the lesions was complete in 32 patients and subtotal in one case. The mean follow-up was 28 months and only two recurrences (6%) were observed in the juvenile angiofibroma group and in the case of the fibrous dysplasia associated to aneurysmal bone cyst, respectively, 20 and 24 months postoperatively.

Conclusion

In selected cases, endoscopic surgery can be considered an effective treatment for the resection of benign tumors involving the sinonasal tract.

Sinonasal Schwannoma: A Rare Sinonasal Neoplasm

Neoplasm in sinonasal cavity is dominated by epithelial type. Sinonasal schwannoma is a rare entity represent less than four percent of head and neck schwannoma. Clinically this tumour is commonly misdiagnosed until they are confirmed by histopathological examination. We present a case of schwannoma in sinonasal region with involvement of right side nasal cavity, maxillary sinus and maxillary alveolar process. The tumour was successfully removed by midfacial degloving approach.

Role of endoscopic surgery in the management of sinonasal and skull base schwannomas

BACKGROUND

The purpose of this study was to report our experience with the endoscopic management of sinonasal schwannomas, analyzing the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 11 patients treated endoscopically between 2000 and 2014 at a single institution.

RESULTS

Eight patients underwent an exclusive endoscopic endonasal approach, whereas, in 3 patients, an osteoplastic flap was combined because of massive or lateral frontal sinus involvement. The tumor extended into the orbit in 5 cases, and involved the skull base in 5 patients who required a concomitant endoscopic duraplasty. No evidence of disease was observed in 10 patients after a mean follow-up of 90.1 months (range, 14-189 months). One patient was alive with persistence of disease, although asymptomatic.

CONCLUSION

The endoscopic endonasal approach is a valid alternative for the vast majority of sinonasal schwannomas with minimal morbidity for the patient. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2074-E2082, 2016.

The intranasal endoscopic removal of schwannoma of the pterygopalatine and infratemporal fossae via the prelacrimal recess approach

OBJECTIVE

This study was undertaken to analyze the results of a novel surgical method-the endoscopic prelacrimal recess approach (PLRA)-in patients with tumors involving the pterygopalatine fossa (PPF) and infratemporal fossa (ITF). The surgical technique and indications for this approach are also discussed.

METHODS

The authors analyzed data from 7 cases involving patients who underwent resection of PPF and ITF tumors by means of the endoscopic PLRA from 2004 to 2013. Preoperative and postoperative imaging studies were available in all cases and were reviewed. The surgical specimens were all confirmed to be schwannomas.

RESULTS

All tumors were completely resected via endoscopic PLRA. There were no recurrences noted over a 28-month follow-up period. In 4 cases, the patients experienced postoperative facial numbness during the first two weeks after surgery, which gradually lessened thereafter. One patient continued to have mild facial numbness at most recent follow-up. The numbness had fully resolved in the other 3 cases.

CONCLUSIONS

The intranasal endoscopic removal of schwannoma from PPF and ITF via PLRA can spare the whole lateral nasal wall, resulting in a reduction in morbidity. This is a novel minimally invasive surgical method for PPF and ITF tumors.

Endoscopic endonasal approach for the treatment of schwannomas of the pterygopalatine fossa: case report and review of the literature

INTRODUCTION

Pterygopalatine fossa (PPF) schwannomas are rare lesions most often arising from branches of the trigeminal nerve. Symptomatic lesions have been traditionally treated by conventional external approaches. However, the development of an expanded endonasal approach (EEA) enables skull base surgeons to reach these deeply seated lesions via a different route with its own advantages and drawbacks.

METHODS

Case report and review of the literature.

CASE DESCRIPTION

A 41-year-old woman presented with a 6-year history of right facial pain and numbness. Her symptoms had increased progressively over a year, and she recently had developed right-sided otalgia. MRI revealed a right PPF mass, hypointense on T1 and T2 sequences with homogeneous enhancement following the use of gadolinium. A biopsy, attempted at another institution, was considered non-diagnostic. We totally removed the lesion through an endoscopic endonasal transmaxillary approach. Final pathology confirmed the diagnosis of schwannoma. Post-operatively, the patient noted a significant improvement of her facial pain (V2 territory).

CONCLUSION

The endonasal endoscopic transmaxillary approach provides adequate access to the PPF, thus enabling safe tumor removal with less morbidity than conventional routes.

CT and MR imaging findings of sinonasal schwannoma: a review of 12 cases

Schwannomas are benign tumors that are rarely found in the sinonasal cavity, and the purpose of this study was to characterize the CT and MR imaging findings of 12 patients with surgically proved sinonasal schwannomas. Assessed features include location, margin, shape, size, internal architecture, pattern and degree of enhancement, and associated bony wall changes. The characteristic CT and MR imaging findings of sinonasal schwannoma include a well-defined soft-tissue mass, most frequently occurring in the nasal cavity and ethmoid sinus with pressure remodeling of the adjacent bony wall. The tumors were isoattenuating on CT and predominantly isointense on both T1- and T2-weighted MR images, compared with the brain stem. Mild contrast enhancement on CT and strong enhancement on MR images were also demonstrated in most of the tumors, and cystic or hemorrhagic changes were noted in 2 cases.

A novel method for three-dimensional analysis of endoscopic spatial relationships of pterygopalatine fossa structures and associated regions

BACKGROUND

The spatial orientation rules of the important skull base structures are essential for performing endoscopic surgery. However, there is no satisfactory three-dimensional (3-D) anatomy study available to the surgeon at present. The aims of this study are to construct a new method to learn the spatial orientation of anatomical features under endoscopy and to help the surgeon establish a 3-D image of skull base structures in his mind.

METHODS

A modified MicronTracker navigation system was used to measure the pitch angle, direction angle and distance from the reference points to various anatomical landmarks of the pterygopalatine fossa and related structures (PPFRS) at the skull base in 10 fresh cadavers (20 sides).

RESULTS

The location data of the positions of the major landmarks were acquired and a digital model of the anatomical structures of the PPFRS was built, which can be moved, whirled or demonstrated easily.

CONCLUSION

It is practical to measure the positions of the anatomical structures of the PPFRS with a modified binocular vision-based MicronTracker navigation system. It is a valuable exploration tool to help the surgeon establish the orientation of surgical landmarks in his mind by the 3-D parameters and model.

Endoscopic endonasal transmaxillary approach and endoscopic sublabial transmaxillary approach: surgical decision-making and implications of the nasolacrimal duct

BACKGROUND

The nasolacrimal duct resides in the wall of the medial nasal cavity and influences minimal access endoscopic transmaxillary approaches to the lateral skull base. We describe an algorithm for surgical approach selection on the basis of the relationship of the target lesion to a line drawn from the anterior nasal SEptum through the Nasolacrimal Duct to the lesion (i.e., SEND line).

METHODS

We use the SEND line to estimate the lateral extent in the endonasal middle meatal transmaxillary approach, where the surgeon has good surgical freedom without the use of angled instruments and endoscopes. Lesions with an epicenter lateral to the SEND line were addressed through a sublabial anterior antrostomy transmaxillary corridor. Tumors with a more medially located epicenter, such as those involving the lateral sphenoid sinus and pterygoid plates, were addressed through the endonasal middle meatal corridor. Extensive tumors involving both domains were addressed through a combination approach.

RESULTS

We describe three instructive cases in which the approach selection was determined in part by preoperative assessment of the location of the tumor relative to the SEND line.

CONCLUSIONS

The endoscopic sublabial transmaxillary and endoscopic endonasal middle meatal transmaxillary approaches are complementary corridors to the anterior skull base that can be used independently or in combination. The location of the target lesion relative to the SEND line as determined on preoperative imaging can serve as a guide for surgical decision making.

Expanded endonasal endoscopic approach for resection of a skull base low-grade smooth muscle neoplasm

Benign smooth muscle tumors rarely occur in the head and neck and, to the best of our knowledge, have not been reported in the pterygopalatine fossa. In this report, we describe a 15-year-old adolescent who presented with facial pain and was found to have a large skull base tumor centered in the pterygopalatine fossa. The patient underwent an expanded endonasal endoscopic approach for complete resection of this lesion with resolution of his symptoms. Pathology revealed a well-differentiated smooth muscle neoplasm consistent with a leiomyoma. This case adds to the growing body of literature supporting a role for endoscopic procedures in the treatment of skull base pathologies in pediatric patients.

Diagnosis and endoscopic management of sinonasal schwannomas

AIMS

Survey the clinical symptoms, radiological features, management, and long-term outcomes of sinonasal and anterior skull base schwannomas.

PATIENTS AND METHODS

Retrospective review of patients with sinonasal schwannomas treated from June 2001 through January 2010 at two academic institutions.

RESULTS

There were 4 women and 3 men in this study. The mean age was 46 years (range 17-68). The mean tumor size was 2.4 cm (range 1.4-3.8 cm). Tumor locations included ethmoid sinuses (3), nasal cavity (2) and pterygopalatine fossa (2). Six patients had endoscopic resections, while 1 was approached and resected via a lateral rhinotomy. The mean follow-up was 2.8 years. There were no tumor recurrences during the study period.

CONCLUSIONS

Schwannomas of the paranasal sinuses and nasal cavity are uncommon tumors that can usually present with vague and nonspecific symptoms. Magnetic resonance imaging can suggest the diagnosis; however, a definitive diagnosis is made by correlation with histopathological findings. Treatment is complete surgical resection. This study illustrates the effectiveness of the endoscopic endonasal approach in the treatment of these benign tumors.

Endoscopic surgical treatment of neurogenic tumor in pterygopalatine and infratemporal fossae via extended medial maxillectomy

CONCLUSION

The endoscopic extended medial maxillectomy approach for the management of lesions of the pterygopalatine and infratemporal fossa provides excellent exposure and results with good hemostasis and low morbidity. This approach is a viable alternative to the open approaches to these areas.

OBJECTIVES

To describe an endoscopic extended medial maxillectomy approach for the treatment of nonmalignant tumors in the pterygopalatine and infratemporal fossa.

METHODS

From January 2004 to June 2007, five patients who had tumors in the pterygopalatine fossa and/or infratemporal fossa, and underwent surgical resection of the tumors with the endoscopic extended medial maxillectomy approach, were reviewed regarding demographics, preoperative images, tumor cell type, surgical techniques, and outcomes.

RESULTS

Five patients underwent the procedure mentioned above; three females and two males with a mean age of 38 and a range of 21-58 years. All patients had adequate exposure and total tumor resection with the endoscopic extended medial maxillectomy approach. None of the patients required an external approach for tumor extirpation. There were no major postoperative complications. No evidence of tumor recurrence was noted after follow-up for 12-78 months.

The endoscopic, endonasal, transmaxillary transpterygoid approach to the pterygopalatine fossa, infratemporal fossa, petrous apex, and the Meckel cave

Object

In this paper the authors' goal was to present their clinical experience with lesions of the pterygopalatine fossa, infratemporal fossa, lateral sphenoid sinus, cavernous sinus, petrous apex, and Meckel cave using simple and extended endoscopic transpterygoid approaches to the lateral skull base.

Methods

Simple and expanded endoscopic transpterygoid approaches were performed in a series of 13 patients with varying pathology that included lateral sphenoid sinus encephaloceles, benign and malignant sinonasal tumors, and lesions of neural origin.

Results

A gross-total resection was achieved in 5 of 9 patients, while a subtotal resection for tissue diagnosis and cytoreduction prior to further adjuvant treatment was performed in the remaining patients. Sphenoid sinus encephaloceles were successfully repaired via a transpterygoid approach in all 4 patients. The skull base defect was reconstructed using a multilayered closure. One patient developed a postoperative CSF leak, which was successfully treated conservatively. The mean follow-up time was 16 months. Five patients complained of recurrent sinusitis. One patient experienced xerophthalmia and palate numbness. Three patients had died by the time of this report. Two patients died of unrelated causes. The third patient died of progression of an aggressive pterygopalatine osteosarcoma despite undergoing cytoreductive surgery and adjuvant chemotherapy.

Conclusions

An endoscopic transpterygoid approach is a minimally invasive endoscopic approach for lesions located or extending to the pterygopalatine fossa, infratemporal fossa, petrous apex, Meckel cave, and other regions of the paramedian skull base.

Endoscopic transnasal resection of ectopic esthesioneuroblastoma in the pterygopalatine fossa: technical case report

OBJECTIVE

Esthesioneuroblastoma is a rare, malignant neoplasm arising from the olfactory neuroepithelium in the upper nasal cavity. Even more rare is ectopic esthesioneuroblastoma developing from the region outside the olfactory epithelium. In addition, tumors occurring in the pterygopalatine fossa (PPF) are uncommon, and the endoscopic transnasal approach for the resection of malignant tumors in this region is also uncommon.

CLINICAL PRESENTATION

We describe an esthesioneuroblastoma arising from the left maxillary sinus and PPF. The tumor was resected using the endoscopic transnasal approach, followed by treatment with radiotherapy. The patient showed no evidence of recurrence 12 months postoperatively.

TECHNIQUE

The endoscopic transnasal approach could be successfully used for the complete removal of malignant tumors in the PPF.

CONCLUSION

The PPF is an anatomic area that is difficult to access. The endoscopic transnasal approach improves access and visualization; it also has the potential to reduce complications compared with the open approach. The endoscopic transnasal approach might become the treatment of choice for malignant tumors in the PPF.

Endoscopic Approach to the Infratemporal Fossa

OBJECTIVE

Classic surgical exposures of the infratemporal fossa region, including the adjacent intracranial space, temporal bone, and sinonasal region, require the extensive exposure associated with the transcranial, transfacial, and transmandibular approaches with their inherent neurological and cosmetic morbidities. In this study, we evaluated the feasibility and exposure afforded by combining 2 endoscopic transmaxillary approaches, endonasal and Caldwell-Luc supplement, to the infratemporal fossa.

METHODS

Endoscopic transmaxillary dissection was performed in 4 formalin-fixed cadaver heads (8 sides). We quantified the extent of exposure achieved within the pterygopalatine and infratemporal fossae after our initial dissection, which was endonasal with a medial antrostomy, and after addition of a Caldwell-Luc incision with an anterior antrostomy. Complementing this anatomic study, we report on a patient in whom this endoscopic transmaxillary approach combining the endonasal and Caldwell-Luc approaches was used for resection of a trigeminal schwannoma in the infratemporal fossa.

RESULTS

The combination of these 2 endoscopic transmaxillary approaches enabled visualization of the entire region of the pterygopalatine fossa and anteromedial aspect of the infratemporal fossa. Additional posterolateral exposure of the infratemporal fossa requires significant traumatic traction on the nose. Addition of the Caldwell-Luc transmaxillary approach exposed the remainder of the infratemporal fossa, including the mandibular nerve and branches, middle meningeal artery, and even the distal cervical portion of the internal carotid artery.

CONCLUSION

Endoscopic exposure of the infratemporal fossa is feasible. Using the combination of the endonasal and Caldwell-Luc approaches for direct transmaxillary access significantly extended exposure, allowing safe and effective resection of infratemporal fossa lesions.

Endoscopic study for the pterygopalatine fossa anatomy: via the middle nasal meatus-sphenopalatine foramen approach

OBJECTIVE

The purposes of this study were to locate the constant anatomic landmarks, which are very important and helpful for endoscopic surgery and not well described for the pterygopalatine fossa (PPF) surgery via the middle nasal meatus-sphenopalatine foramen approach to establish a safe surgical mode.

METHODS

Eight cases of adult skull specimens were selected for the simulated surgery. The Messerklinger surgical approach was used under the endoscope. The uncinate process was removed successively, and the anterior ethmoid sinus and posterior ethmoid sinus were opened. The opening of the maxillary sinus was identified and was expanded forward and backward. The ethmoidal crest was found and was used as an anatomic landmark to find the sphenopalatine foramen. The sphenopalatine artery was protected and was used as a guide to enter the PPF region. The sphenopalatine artery was followed conversely to anatomize the blood vessels and nerves in the PPF.

RESULTS

It was found that our surgical procedure provides a clear view of the constant anatomic landmark including ethmoidal crest and sphenopalatine foramen. By retrograde dissection, following the sphenopalatine artery, which runs out of the sphenopalatine foramen behind the ethmoidal crest, the internal maxillary artery (IMA) and the branches of the IMA in the PPF were exposed. Posterior to the sphenopalatine artery, the typical Y-shaped structure with the pterygopalatine ganglion as the center was visible when the IMA and its branches were moved downward and outward. The Y structure, which is consisted of the pterygopalatine ganglion, branches of the internal maxillary nerve, vidian nerve, and descending palatine nerve, served as the other anatomic landmark. By following the Y structure, it was easy to locate the pterygoid canal, foramen rotundum, and the infraorbital nerve, and the integrity of the nerve structure could be protected.

CONCLUSION

Endoscopic PPF surgery via the middle nasal meatus-sphenopalatine foramen approach is safe, and the ethmoidal crest, sphenopalatine foramen, and Y structure with the pterygopalatine ganglion in the center are important anatomic landmarks that can be referred to during the surgery.

Endoscopic sublabial transmaxillary approach to the rostral middle fossa

OBJECTIVE

The rostral middle fossa faces the temporal pole and is the endocranial anterosuperior aspect of the greater wing of the sphenoid. Standard approaches to this region, such as the subtemporal, pterional, or orbitozygomatic approaches, require significant brain retraction or manipulation of the temporalis muscle. We report an endoscopic sublabial transmaxillary approach to this cranial base region that avoids the aforementioned pitfalls.

METHODS

Ten adult cadaveric half heads were used to develop the endoscopic approach and to identify the salient surgical landmarks.

RESULTS

The approach was divided into three stages: entry into the maxillary sinus, entry into the infratemporal fossa, and entry into the middle fossa. A craniotomy of greater than 20 mm in diameter can be safely created in the rostral middle fossa. When coupled with image guidance, the approach provides the flexibility to tailor the size and location of the middle fossa craniotomy.

CONCLUSION

Although endonasal endoscopic approaches are increasing in popularity, the middle fossa has not been adequately accessed with these techniques. The endoscopic sublabial transmaxillary approach provides safe and direct access to the rostral middle fossa, eliminating the need for brain retraction, temporalis muscle manipulation, or an external incision. The approach also permits early devascularization of cranial- or dural-based lesions.

Schwannoma of the inferior turbinate: case report and review of literature

Schwannomas of the sinonasal tract are rare entities that are amenable to local resection. We present a 69 year old woman with a schwannoma of the inferior turbinate that was successfully resected. Schwannomas arising from the inferior turbinate are very infrequent.

[Schwannoma of the nasal cavity: a case report]

Schwannomas of the nasal cavity and paranasal sinuses are quite rare, with 4% occurring in this location. Most of them are benign and do not recur when totally removed by surgery. It is very important to distinguish between schwannoma and primary benign neurofibroma. Neurofibromas are lesions having the possibility for malignant transformation and recurrence. A case of schwannoma in the nasal cavity is reported, and the diagnostic and therapeutic procedures, as well as recommendations from the literature, are described. The histological and immunohistochemical features are discussed in detail to draw a distinction between schwannoma and neurofibroma. In cases of intranasal and paranasal lesions, the existence of a schwannoma must be considered. Differentiating between schwannoma and neurofibroma is important for estimating the risk of malignant transformation and recurrence.

Endoscopic anatomy of the pterygopalatine fossa and the transpterygoid approach: development of a surgical instruction model

INTRODUCTION

The pterygopalatine fossa (PPF) is a narrow space located between the posterior wall of the antrum and the pterygoid plates. Surgical access to the PPF is difficult because of its protected position and its complex neurovascular anatomy. Endonasal approaches using rod lens endoscopes, however, provide better visualization of this area and are associated with less morbidity than external approaches. Our aim was to develop a simple anatomical model using cadaveric specimens injected with intravascular colored silicone to demonstrate the endoscopic anatomy of the PPF. This model could be used for surgical instruction of the transpterygoid approach.

METHODS

We dissected six PPF in three cadaveric specimens prepared with intravascular injection of colored material using two different injection techniques. An endoscopic endonasal approach, including a wide nasoantral window and removal of the posterior antrum wall, provided access to the PPF.

RESULTS

We produced our best anatomical model injecting colored silicone via the common carotid artery. We found that, using an endoscopic approach, a retrograde dissection of the sphenopalatine artery helped to identify the internal maxillary artery (IMA) and its branches. Neural structures were identified deeper to the vascular elements. Notable anatomical landmarks for the endoscopic surgeon are the vidian nerve and its canal that leads to the petrous portion of the internal carotid artery (ICA), and the foramen rotundum, and V2 that leads to Meckel's cave in the middle cranial fossa. These two nerves, vidian and V2, are separated by a pyramidal shaped bone and its apex marks the ICA.

CONCLUSION

Our anatomical model provides the means to learn the endoscopic anatomy of the PPF and may be used for the simulation of surgical techniques. An endoscopic endonasal approach provides adequate exposure to all anatomical structures within the PPF. These structures may be used as landmarks to identify and control deeper neurovascular structures. The significance is that an anatomical model facilitates learning the surgical anatomy and the acquisition of surgical skills. A dissection superficial to the vascular structures preserves the neural elements. These nerves and their bony foramina, such as the vidian nerve and V2, are critical anatomical landmarks to identify and control the ICA at the skull base.

The endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa: comparison of endoscopic and radiological landmarks

OBJECTIVE

The endoscopic endonasal approach offers the opportunity to reach the pterygopalatine fossa, the lateral recess of the sphenoid sinus, and other areas of the cranial base through a minimally invasive approach. This study compares the anatomy of these areas when observed through an endoscopic endonasal view with the anatomy of the same regions as they appear in computed tomographic scans. The aim was to identify and correlate the corresponding anatomic structures, providing the surgeons with anatomic landmarks to guide them when operating in these areas through an endoscopic endonasal approach.

METHODS

An anatomic dissection of six fixed cadaver heads was performed by an endoscopic endonasal approach. A step-by-step comparison of endoscopic and radiological images was made to identify the landmarks of the surgical field.

RESULTS

The step-by-step comparison of endoscopic and radiological images acquired during the endoscopic endonasal approach to the lateral recess of the sphenoid sinus via the pterygopalatine fossa allowed the identification of all the relevant anatomic landmarks of the procedure.

CONCLUSION

The endoscopic endonasal approach via the pterygopalatine fossa offers direct, minimally invasive access to the lateral recess of the sphenoid sinus, which can be monitored in each phase through consistent radiological imagery.

Schwannoma of the Nasal Cavity

Schwannomas are benign peripheral nerve sheath tumors that occur throughout the body. They may present as either solitary or multiple masses. They rarely occur in the nasal cavity. The diagnosis is often made only after histologic examination. Because these lesions are radioresistant, the preferred treatment is complete surgical excision. We present a new case of a schwannoma of the nasal cavity.

Anatomical study of the pterygopalatine fossa using an endoscopic endonasal approach: spatial relations and distances between surgical landmarks

OBJECT

The pterygopalatine fossa is an area that lies deep within the skull base. The recent extensive use of the endoscopic endonasal approach has provided neurosurgeons with a method to reach various areas of the skull base through a less invasive approach than traditional transcranial or transfacial approaches. This study aims to provide neurosurgeons with new data concerning direct endoscopic measurements and precise anatomical topography features of the pterygopalatine fossa.

METHODS

An anatomical dissection of six fixed cadaver heads (12 pterygopalatine fossae) was performed to analyze spatial relationships and distances between the most important neurovascular structures in this region, and to estimate the size of the endoscopic surgical field for operations in this area. The endoscopic endonasal approach offers direct access to the pterygopalatine fossa through its anteromedial walls.

CONCLUSIONS

Using an endoscopic endonasal approach makes it possible to identify all of the anatomical landmarks of the pterygopalatine fossa and almost all of the contiguous skull base areas.

Endoscopic sinus surgery for the treatment of vascular tumors

BACKGROUND

This study points out the effectiveness of the endoscopic approach for the treatment of vascular lesions such as angiofibroma, hemangioma, and hemangiopericytoma involving the nose and paranasal sinuses.

METHODS

We performed a retrospective study at an academic tertiary referral center. Thirteen patients, diagnosed with vascular tumors of the nose and paranasal sinuses were treated endoscopically between February 1996 and July 2003. All patients underwent endonasal endoscopic surgery. Preoperative angiography with embolization was performed in all but two cases.

RESULTS

The follow-up of this series varied from 6 to 75 months (mean, 23 months); only one recurrence (8%) was observed in the juvenile angiofibroma group encountered 20 months postoperatively. This recurrence was again treated endoscopically. The average intraoperative blood loss for the removal of the juvenile angiofibroma group was 300 mL and it was 100 mL for the other vascular tumors.

CONCLUSION

Endoscopic treatment alone is an effective approach for the removal of selected cases of vascular tumors. Even in the presence of a lesion with limited intracranial extension, the tumor still may be amenable to an endoscopic approach alone. On the contrary, this is not true if the intracranial extension receives feeding vessels from the internal carotid arterial system.

Combined endoscopic transmaxillary-transnasal approach to the pterygoid region, lateral sphenoid sinus, and retrobulbar orbit

OBJECTIVES

The sublabial transmaxillary approach to the pterygoid region was a popular one during the Caldwell-Luc, pre-endoscopic era. It was the procedure of choice for management of lesions of the pterygopalatine space, for internal maxillary artery ligation, and for vidian neurectomy. With the introduction of endoscopic instrumentation and techniques, the Caldwell-Luc procedure is rarely performed today. Also, because vidian neurectomy is performed less frequently, and because internal maxillary artery ligation for severe epistaxis has been replaced with transnasal endoscopic sphenopalatine artery ligation, the sublabial transmaxillary route is rarely used. We have found that combining the use of endoscopes via the sublabial approach and the transnasal endoscopic approach is very helpful for management of extreme lateral lesions of the sphenoid sinus, as well as the pterygoid region and the posterior orbit.

METHODS

The records of patients who underwent a combined endoscopic transmaxillary-transnasal approach between 1994 and 2002 were reviewed. Indications for the procedure included extreme lateral sphenoid and pterygoid encephalocele (3 patients), pterygoid mucocele (2 patients), orbital apex lesion (2 patients), and pterygopalatine tumor (2 patients).

RESULTS

Nine patients underwent the above-mentioned procedure. Wide and comfortable exposure of the involved region was achieved in all cases. Compared with the transnasal approach, the working distance, working comfort, and maneuverability of instruments were significantly enhanced. There were no major complications related to the approach. Because the maxillary wall opening is very small, infraorbital hypoesthesia is very limited and of short duration.

CONCLUSIONS

Combining the transmaxillary and transnasal approaches for endoscopic management of pterygoid, lateral sphenoid, and retrobulbar orbit lesions provides excellent exposure and avoids the limited working angle and surgical struggle that may be associated with the use of the transnasal approach alone.

Extended endoscopic endonasal approach to the pterygopalatine fossa: anatomical study and clinical considerations

Object

The pterygopalatine fossa is an area located deep in the skull base. The microsurgical transmaxillary–transantral route is usually chosen to remove lesions in this region. The increasing use of the endoscope in sinonasal functional surgery has more recently led to the advent of the endoscope for the treatment of tumors located in the pterygopalatine fossa as well.

Methods

An anatomical dissection of three fresh cadaveric heads (six pterygopalatine fossas) and three dried skull base specimens was performed to evaluate the feasibility of the approach and to illustrate the surgical landmarks that are useful for operations in this complex region.

The endoscopic endonasal approach allows a wide exposure of the pterygopalatine fossa. Furthermore, with the same access (that is, through the nostril) it is possible to expose regions contiguous with the pterygopalatine fossa, either to visualize more surgical landmarks or to accomplish a better lesion removal.

Conclusions

In this anatomical study the endoscopic endonasal approach to the pterygopalatine fossa has been found to be a safe approach for the removal of lesions in this region. The approach could be proposed as an alternative to the standard microsurgical transmaxillary–transantral route.

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.

Schwannoma of the nasal septum: a case report

Schwannoma is a neurogenic tumor arising from the sheath of myelinated nerves. Only 4% of schwannomas located in the head and neck region involve the sinonasal tract, and those arising from the nasal septum are exceedingly rare. We report a case of a 55-year-old male who presented with only right nasal obstruction. Computerized tomography and clinical examination suggested a benign tumor before the tumor was completely removed by transnasal endoscopic surgery. When encountering a mass in the nasal cavity, schwannoma should be borne in mind in the differential diagnosis. We discuss the clinical presentation, histologic features, differential diagnosis, and therapeutic options for such a rare lesion.

Endoscopic transnasal transpterygopalatine fossa approach to the lateral recess of the sphenoid sinus

OBJECTIVES

Lesions affecting the lateral recess of the sphenoid sinus are rarely discussed in the literature as a separate entity. This region is difficult to visualize and manipulate through the transnasal routes, especially when extensive pneumatization is present. External approaches to this area involve extensive surgery and are associated with significant morbidity. The objectives of this study are to present our experience with the endoscopic transpterygopalatine fossa approach as a method for exposing and manipulating lesions of the lateral recess of the sphenoid and to illustrate the detailed surgical steps of the procedure.

STUDY DESIGN

Retrospective review.

METHODS

Clinical charts of patients who had lesions originating from or extending into the lateral recess of the sphenoid sinus and who were treated at our institutions from September 1995 to June 2002 were retrospectively reviewed. All these patients were managed by the endoscopic transpterygopalatine fossa approach.

RESULTS

Twelve patients (7 males and 5 females) were included in the study. Lesions included seven cerebrospinal fluid (CSF) leaks and five tumors. One patient with squamous cell carcinoma (SCC) of the sphenoid died of his disease. All CSF leaks were successfully repaired, and benign tumors were removed with good local control through the follow-up period.

CONCLUSION

The endoscopic transpterygopalatine fossa approach is an excellent approach for dealing with lesions of the sphenoid lateral recess.