{'fraction_non_alphanumeric': 0.04035512510088781, 'fraction_numerical': 0.03470540758676352, 'mean_word_length': 4.486725663716814, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Transnasal Approach to the Anterior Skull Base: An Endoscopic Anatomic Study

ObjectiveThe purpose of this study was to locate the constant anatomic landmarks for anterior skull base surgery via endoscopic transnasal approach in Chinese subjects. MethodsEight cases of adult skull specimens (all Chinese) were dissected by the endoscopic transnasal approach. The relationships of the anatomic landmarks under endoscopic view were characterized. The distance between the columella and the anterior ethmoid artery (AEA) or the posterior ethmoid artery (PEA) was measured. ResultsThe uncinate process attached to the lamina papyracea in 7 sides (43.8%), to the skull base in 4 sides (25%), and to the middle turbinate in 3 sides (18.8%). In addition, the uncinate process was found to have bifurcated attachment in 2 sides (12.5%).The mean ± SD distance from the columella to the AEA was 62.71 ± 2.18 mm on the right side and 63.38 ± 1.69 mm on the left side. The mean ± SD distance from the columella to the PEA was 70.91 ± 1.99 mm on the right side and 71.79 ± 1.95 mm on the left side. ConclusionsThe frontal recess, the AEA, and the PEA can serve as the constant landmarks in the transnasal endoscopic approach to the anterior skull base.