Endoscopic transpterygoid nasopharyngectomy: correlation of surgical anatomy with multiplanar CT.

BACKGROUND: Oncologic resection of the nasopharynx is challenging due to its complex and deep-seated nature. We aimed to illustrate the anatomic landmarks of endoscopic nasopharyngectomy and design a surgical training model that could facilitate learning of this technique. METHODS: An endoscopic endonasal dissection of the nasopharynx was completed in fresh cadaveric specimens under conditions similar to those of our operating suite. Digital data from a high-resolution CT scan were imported to an image guidance system to be used during the dissections. RESULTS: We expanded the sinonasal corridor, harvested a contralateral nasoseptal flap, and exposed the pterygopalatine and infratemporal fossae. A detailed anatomic dissection of the nasopharynx was correlated to multiplanar images provided by the image guidance system, highlighting appropriate bony, neural, and vascular landmarks. CONCLUSIONS: Understanding the anatomy-based endoscopic modular approaches facilitates planning and safe execution of an oncologic nasopharyngectomy. Clinical experience remains mandatory because anatomic models fall short of clinical scenarios.

Endonasal transpterygoid approach to the infratemporal fossa: correlation of endoscopic and multiplanar CT anatomy.

BACKGROUND: The infratemporal fossa anatomy, from an endoscopic standpoint, is poorly understood. Our purpose was to design an anatomic model that illustrates the anatomy of the infratemporal fossa from the endoscopic standpoint and serves as a training model for surgeons interested in pursuing this endeavor. METHODS: Red and blue silicone dyes were respectively injected into the great vessels of the neck. Digital data acquired from a high resolution CT scan was imported to a navigational system. An endoscopic endonasal dissection of the infratemporal fossa was completed under conditions that mimicked our operating suite. RESULTS: A detailed anatomic dissection of the infratemporal fossa was correlated to the image guidance (navigation) system. This provided a surgical map highlighting critical neurovascular structures and illustrating the potential surgical corridors. CONCLUSION: A thorough understanding of the anatomy of infratemporal fossa from the endoscopic perspective allows the surgeon to plan an adequate corridor.

Rhinocerebral mucormycosis: pathways of spread.

Rhinocerebral mucormycosis is an invasive, opportunistic fungal infection usually seen in immunocompromised patients, and particularly in the setting of diabetes or immune deficiency. It is assumed that the port of entry is colonization of the nasal mucosa, allowing the fungus to spread via the paranasal sinuses into the orbit. Involvement of the brain and cavernous sinus occurs by way of the orbital apex; therefore, spheno-ethmoidectomy with or without maxillectomy seems to be the definitive method to eradicate this infection. We conducted a prospective study of ten patients with rhinocerebral mucormycosis from February 2000 to April 2004. Rhinocerebral mucormycosis was clinically diagnosed in 11 patients, 10 of whom were included in our study upon histopathological confirmation. Diabetes was the most common underlying disorder seen in nine out of ten patients. In this study, the patients were assessed for predisposing factors, presenting signs and symptoms, sites of extension, the number and sites of surgical debridement, as well as the outcome. Ocular, sinonasal and facial soft tissue involvement was common. Involvement of the pterygopalatine fossa at the time of debridement was evident in all patients. No invasion through the lamina papiracea or the walls of the maxillary sinus was identified. At the time of this communication, six out of ten patients were alive. For the four who died, the causes were hypokalemia, cardiac arrythmia and refractory pneumonia. Pterygopalatine fossa is considered to be the main reservoir for rhinocerebral mucormycosis, and extension into the orbit and facial soft tissues usually follows this route. After proliferation in the nasal cavity, the mucor reaches the pterygo-palatine fossa, inferior orbital fissure and finally the retroglobal space of the orbit, resulting in ocular signs. The facial soft tissues, palate and infratemporal fossa can be infected through connecting pathways from the pterygo-palatine fossa; therefore, debridement of the pterygopalatine fossa seems to be the definitive method of managing this infection.