2025 Proffered Presentations
S312: TRANSORBITAL NEUROENDOSCOPIC TRANSMAXILLARY APPROACH TO THE PTERYGOPALATINE FOSSA (TONES-TMAX): ANATOMICAL DESCRIPTION AND SURGICAL CASE ILLUSTRATION.
Juan Felipe Abaunza-Camacho, MD1; Sara Gomez-Niebles, MD1; Rafael Aponte-Caballero, MD2; Camilo Benavides-Burbano, MD3; Maximiliano Alberto Nunez, MD4; Humberto Madrinan-Navia, MD5; William M. Riveros-Castillo, MD, MSc2; Javier M. Saavedra, MD, MSc6; 1Universidad del Rosario School of Medicine and Health Sciences, Bogota, Colombia; 2Department of Neurosurgery, Hospital Universitario Mayor Méderi, Bogotá, Colombia; 3Department of Neurosurgery, Hospital Universitario de la Samaritana, Bogotá, Colombia; 4Department of Neurosurgery, Hospital El Cruce, Buenos Aires, Argentina; 5Center for Research and Training in Neurosurgery; 6Center for Research and Training in Neurosurgery (CIEN), Bogotá, Colombia.
Background: The infratemporal fossa (ITF) and pterygopalatine fossa (PPF) are deep-seated structures in the skull base that can harbor multiple pathologies of interest to neurosurgeons.
Classical approaches, including the lateral (Fisch and middle fossa approaches) and anterior (transfacial) approaches, are highly morbid.
With the advent of endoscopic surgery, minimally invasive techniques have become part of the neurosurgeon's armamentarium. However, the endonasal trasnsmaxillary approach (EMA) to the pterygopalatine fossa implies a broad dissection of the osseous structures of the nose and implies a later proximal vascular control of the internal maxillary artery (IMA).
In 2010, Moe et al. described transorbital neuroendoscopic surgery (TONES), a set of surgical corridors that reach the paramedian and paraclival segments of the skull base. This approach has reached the ITF and PPF between the superior and inferior orbital fissures.
This study aimed to describe a transorbital neuroendoscopic transmaxillary approach (TONES-Tmax) utilizing the maxillary sinus (MS) to gain access to the PPF with an early proximal vascular control of the IMA.
Methods: One fresh-frozen latex-injected cadaver was used for the anatomical dissection, which was performed using a rigid endoscope with a 0° and 30° lens. We also present a case report of a transorbital brain injury (TOBI) in which the foreign object reached the right PPF and ITF successfully treated through TONES.
Results: An extended superior eyelid approach with a lateral orbitotomy was performed. A subperiosteal dissection was made to reach the inferior orbital fissure (IOF) (FIGURE 1). The maxillary sinus roof and the infraorbital nerve (ION) were identified, and lateral drilling was performed. (FIGURE 2)
The subperiosteum of the ITF and contained fat tissue were removed, identifying the superior and inferior heads of the lateral pterygoid muscle and the first segment of the IMA, allowing early vascular control compared to TONES or EMA approaches.(FIGURE 2 AND 3)
In the PPF, the pterygopalatine ganglion (PPG) was identified in relation to the ION. At the depth of the PPF, the PPG gives the nasopalatine and pharyngeal nerves. These structures set the boundaries to the PPF with the maxillary nerve superiorly, the vertical portion of the palatine bone medially, and the ITF laterally. (FIGURE 3)
Illustrative case: A 23-year-old male presented to the emergency department following a TOBI with a knife in the right orbit. Images showed a metallic foreign object that reached the right ITF and PPF. The knife penetrated through the lateral wall of the orbit in anteroposterior and lateromedial trajectory, crossing the maxillary sinus and lodging in the pterygopalatine fossa.
Given the high risk of vascular injury, an emergent surgical procedure was performed through TONES, accessing the ITF, PPF and locating the IMA.
The knife was successfully dislodged without any complications, and the patient was discharged on day two postoperatively. (FIGURE 4)
Conclusions: TONES-Tmax provides direct access to ITF, PPF, and its structures with early proximal vascular control and minimal disruption of the maxillary sinus with the advantages of minimally invasive approaches and satisfactory clinical results.