ORIGINAL ARTICLE Endoscopic Transnasal Approach to the Pterygopalatine Fossa John M. DelGaudio, MD Objective: To describe an endoscopic transnasal ap- through the same approach with further lateral expo- proach to the pterygopalatine fossa (PPF). sure to the area of the inferior orbital fissure. Design: Case series of 3 patients. Results: All patients had successful endoscopic ap- proaches for tumor removal (case 1) and biopsy (cases Setting: An academic medical center. 2 and 3) of the PPF. The second patient had a repeat en- doscopic biopsy 1 week later to obtain more tissue for Patients: One patient presented with an asymptomatic diagnostic purposes. None of the patients had any ma- PPF schwannoma. The second patient presented after a jor vascular complications. At follow-up, 2 of 3 patients sudden onset of complete unilateral vision loss with a com- had persistent sensory deficits. plete ipsilateral sphenoid sinus opacification and radio- graphic signal abnormality in the PPF and inferior or- bital fissure. The third patient had a history of adenoid Conclusions: The endoscopic transnasal approach to the cystic carcinoma of the lacrimal gland, and was found PPF is a safe and effective method for biopsy and re- to have new-onset facial numbness. moval of PPF masses. The endoscopic approach im- proves access and visualization, and has the potential to Intervention: One patient had a complete excision of reduce complications compared with open approaches. a schwannoma by means of an endoscopic transnasal ap- Image guidance is helpful in these cases. proach. The other 2 patients had wide exposure and bi- opsies of the PPF. One patient had a revision procedure Arch Otolaryngol Head Neck Surg. 2003;129:441-446 NDOSCOPIC SURGERY has ery periods when compared with stan- gained universal accep- dard open approaches. tance as the surgical The pterygopalatine fossa (PPF) is a method of choice for the difficult-to-access anatomic area. It is lo- treatment of inflammatory cated behind the posterior wall of the max- Esinonasal disease. With increasing famil- illary sinus, bordered by the pterygoid iarity with endoscopic techniques, plates posteriorly and the greater sphe- increased understanding of sinus and noid wing and middle cranial fossa supe- perisinus anatomy, and advanced tech- riorly. It has connections with the infra- nology in the form of instrumentation temporal fossa laterally through the and image-guided systems, there has pterygomaxillary fissure, the posterior na- been a natural extension of these tech- sal cavity medially through the spheno- niques to include treatment of other dis- palatine foramen, the orbit superiorly ease processes. These include endoscopic through the inferior orbital fissure, and the treatment of sinus and skull base palate inferiorly through the palatine fo- tumors,1-3 repair of cerebrospinal fluid ramina. Structures contained within the leaks and meningoencephaloceles,4,5 PPF include the internal maxillary artery orbital decompression,6,7 approaches to and its branches, the maxillary division of From the Department of the orbital apex and clivus,8,9 transsphe- the trigeminal nerve (V ), and the vidian Otolaryngology–Head and 2 noidal approaches to the pituitary,10 and nerve. Tumors of the PPF are uncom- Neck Surgery, Emory 11,12 University School of Medicine, arterial ligations for epistaxis. These mon, with the most common being nerve Atlanta, Ga. Dr DelGaudio has approaches allow good visualization sheath tumors. no relevant financial interest in of difficult-to-access locations with Standard approaches to the PPF re- this article. decreased morbidity and shorter recov- quire transmaxillary techniques that vio- (REPRINTED) ARCH OTOLARYNGOL HEAD NECK SURG/ VOL 129, APR 2003 WWW.ARCHOTO.COM 441 ©2003 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 Figure 1. Case 1. Coronal computed tomographic scan of the sinuses shows a schwannoma in the right pterygopalatine fossa (thin arrow). The left pterygopalatine fossa is normal (thick arrow). Figure 2. Case 1. Axial magnetic resonance image shows a late the anterior and posterior walls of the maxillary si- well-circumscribed mass in the right pterygopalatine fossa causing anterior nus, with the risks of facial edema and pain, infraorbital displacement of the posterior wall of the maxillary sinus. nerve injury, oroantral fistula, chronic maxillary sinus- itis, and vascular injury. An endoscopic approach to the PPF can potentially reduce these risks, along with pro- Caldwell-Luc operation if necessary. The patient was viding better visualization than headlight- or microscope- counseled regarding the risk of vascular injury to the in- directed approaches. Herein we report an endoscopic ap- ternal maxillary artery and the possible need to convert proach to the PPF for definitive resection of a schwannoma to an open approach. in 1 patient and for biopsy of the PPF in 2 other pa- The procedure was begun with a large maxillary an- tients. trostomy, ethmoidectomy, and wide sphenoidotomy to expose the medial and anterior aspects of the tumor REPORT OF CASES (Figure 3). The mucosa of the posterior maxillary si- nus was elevated from superomedial to inferolateral. The CASE 1 thinned posterior wall of the maxillary sinus was easily removed from the anterior and superior surfaces of the A 33-year-old woman was referred for evaluation of a right PPF mass to expose the capsule. The sphenopalatine ar- PPF mass identified on sinus computed tomographic (CT) tery was dissected from the surface and medial aspect of scan ordered for evaluation of recurrent nasal conges- the mass, cauterized, and transected medially to com- tion. The CT scan showed a well-circumscribed PPF mass pletely free the medial aspect of the tumor. The tumor that had thinned and anteriorly displaced the posterior was then bluntly dissected off of the pterygoid plates pos- wall of the maxillary sinus (Figure 1). Magnetic reso- teriorly. Because of the tight confines of the PPF and the nance imaging showed the mass to be well circum- dense inferior attachments of the tumor to the vascula- scribed and isointense with brain on T2 images, to en- ture of the PPF, the tumor could not be removed en bloc. hance with gadolinium, and to have a slightly The capsule was therefore opened to allow complete re- heterogeneous appearance (Figure 2). The patient de- moval of the tumor. The inferior portion of the tumor nied facial paresthesia or pain, and results of neurologic was removed last, after identification and clipping of the examination were normal. Endoscopic examination main trunk and branches of the internal maxillary ar- showed only fullness in the lateral nasal wall adjacent to tery (Figure 4). After confirmation of complete tumor the posterior attachment of the right middle turbinate. removal and irrigation of the PPF, the surgical area with The mass was presumed to be a nerve sheath tumor on exposed pterygoid periosteum was covered with a dis- the basis of the clinical and radiologic data. solvable hyaluronic acid pack. An endoscopic transnasal approach for resection of Postoperatively the patient was observed overnight the mass was recommended to the patient. Consent was and discharged the following morning. She did develop also obtained for a canine fossa approach and possible numbness in the distribution of the maxillary division (REPRINTED) ARCH OTOLARYNGOL HEAD NECK SURG/ VOL 129, APR 2003 WWW.ARCHOTO.COM 442 ©2003 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/30/2021 MT S T ∗ Figure 5. Case 2. Axial computed tomographic scan shows asymmetry of Figure 3. Endoscopic view of pterygopalatine fossa schwannoma (T) before the pterygopalatine fossa, with the right side showing loss of normal removal of overlying thinned bone of maxillary sinus. MT indicates middle soft-tissue architecture (thin arrow) compared with the left (thick arrow). turbinate; S, sphenoid sinus; and asterisk, suction cannula. Sphenoid sinus (asterisk) is opacified with a heterogeneous appearance suggestive of fungal contents. MT PP S IMA N M IT Figure 6. Case 2. Coronal magnetic resonance image shows normal tissue signal of the left pterygopalatine fossa (black arrow) and orbital apex (thick Figure 4. Endoscopic view of pterygopalatine fossa. The internal maxillary white arrow), but the right pterygopalatine fossa and orbital apex tissues artery (IMA) is isolated and the sphenopalatine artery (arrow) has been show loss of normal tissue signal (thin white arrows). S indicates sphenoid clipped. A nerve (N) is seen exiting from the final piece of tumor (asterisk) sinus. located behind the IMA. MT indicates middle turbinate; IT, inferior turbinate; PP, pterygoid plates; and M, posterior wall of maxillary sinus. were normal. No other cranial nerve abnormalities were identified. of V2 that minimally improved during the next 12 A CT scan of the sinuses disclosed right sphenoid months. Follow-up CT scan and serial evaluations opacification with hyperostosis of the sinus walls. The showed no evidence of recurrence 6 months postopera- sphenoid contents had a heterogeneous appearance. There tively. was no extension outside of the sinus, and the remain- der of the sinuses was clear. No bone erosion was pres- CASE 2 ent. There was a subtle asymmetry of the soft-tissue char- acteristics in the right PPF (Figure 5). Magnetic A 44-year-old woman was referred for evaluation 6 resonance imaging demonstrated the same asymmetry in weeks after developing complete vision loss in the right the PPF. The soft tissue in the right PPF displayed loss eye that occurred during 36 hours. Her vision did not of normal enhancement, and this extended to the infe- respond to high-dose oral and intravenous corticoste- rior orbital fissure and the orbital apex. No discrete mass roids. Ophthalmologic examination showed only mini- was identified (Figure 6). The radiologic appearance mal light perception in the right eye and no other and clinical history were suggestive of an infiltrative pro- abnormalities.