2025 Poster Presentations
P339: TWO TRIANGLES AS LANDMARKS FOR THE UPPER PARAPHARYNGEAL INTERNAL CAROTID ARTERY: SURGICAL ANATOMY AND RELEVANCE FOR THE ENDOSCOPIC ANTERIOR TRANSMAXILLARY AND ENDONASAL APPROACHES TO THE INFRATEMPORAL FOSSA AND PARAPHARYNGEAL SPACE
Liang Xia1,2; Jiabin Zhan1,3; I-sorn Phoominaonin1,4; Kyle Affolter1; Maria Karampouga1; Carl H Snyderman3,4; Eric W Wang5; Garret W Choby3,4; Georgios A Zenonos3,4; Paul A Gardner1; 1Department of Neurological Surgery, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States; 2Department of Neurosurgery, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China; 3Department of Otorhinolaryngology Head and Neck Surgery, Hainan Affiliated Hospital of Hainan Medical University (Hainan General Hospital), Haikou, China; 4Faculty of Science and Health Technology, Navamindradhiraj University, Bangkok, Thailand; 5Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
BACKGROUND AND OBJECTIVES: The upper parapharyngeal internal carotid artery (upper-ppICA) is perhaps one of the most challenging segments of the artery to surgically localize and control. Understanding the relevantis anatomy is crucial for endoscopic access to the infratemporal fossa (ITF) and parapharyngeal spaces (PPS). This study evaluates the surgical significance of two wo anatomical triangles (six key points) including namely an the “ACCESS” and triangle and “DANGER” triangles as the landmarks for the upper-ppICA localization during the endoscopic sublabial anterior transmaxillary and endonasal approaches (ESATMA and EEA).
METHODS: To conduct this study, fFive cadaveric specimens (10 sides) were dissected. The ITF and PPS were accessed fisrt through the ESATMA and at a second stage in combination with the EEA. The anatomical relationships of the critical ITF and PPS contents with upper-ppICA were defined and subsequently as dissected. The 2 anatomical triangles were defined, described, and stereotactically measured using neuronavigation.
RESULTS: In order to identify the upper-ppICA, six specific specific points were designated within the ESATMA: A (cranial entry point of lingual nerve), B (lingual nerve junction point with the base of the maxillary sinus), C (eustachian tube cartilage junction point with the maxillary sinus base), D (cranial entry point of the middle meningeal artery (MMA)), E (origin of the MMA from the internal maxillary artery (IMA)), and F (junction point of the posterior inferior margin of levator veli palatini and maxillary sinus base). The distance from the upper-ppICA (at the same axial level) to the A, B, C, D, E, and F points was measured as at 22.2mm, 19.5mm, 31.7mm, 12.1mm, 12.1mm and 10.5mm by via ruler, respectively. FurthermoreBased on that, 2 triangles were defined: 1) The "ACCESS" triangle, comprised of points ABC, was initially encountered and facilitated access of the ppICA, points ABC constituted the ACCESS triangle, and DEF constituted 2) the DANGER triangle, constituted of points DEF, and as its name denotes, was the final gate to the upper ppICA. These triangles reliably localized the upper-ppICA as a key step in anatomical exploration of the pterygopalatine fossa, ITF and PPS via the ESATMA.
CONCLUSION: The 2 triangles described herein (6 key points) serve as novel anatomical landmarks for the localization of the upper-ppICA during the ESATMA , with of without EEA biportal entry, in accessing the ITF and PPS. These landmarks can be utilized independently seperately or in conjunction, offering valuable guidance for surgeons in the precise and secureefficient and safe treatment of tumors or other lesions within these regions.
Figure 1. The 6 key points and the two triangles of the ITF and PPS through the endoscopic sublabial anterior transmaxillary approach.