Endoscopic transorbital decompression for traumatic superior orbital fissure syndrome: from cadaveric study to clinical application.

PURPOSE: The endoscopic endonasal approach (EEA) is a minimally invasive and promising modality for treating traumatic superior orbital fissure (SOF) syndrome (tSOFS). Recently, the endoscopic transorbital approach (ETOA) has been considered an alternative method for reaching the anterolateral skull base. This study accessed the practicality of using the ETOA to treat SOF decompression using both cadaveric dissection and clinical application. METHODS: Bilateral anatomic dissections were performed on four adult cadaveric heads using the ETOA and EEA to address SOF decompression. The ETOA procedure for SOF decompression is described, and the extent of SOF decompression was compared between the ETOA and EEA. The clinical feasibility of the ETOA for treating SOF decompression was performed in two patients diagnosed with tSOFS. RESULTS: ETOA allowed for decompression over the lateral aspect of the SOF, from the meningo-orbital band superolaterally to the maxillary strut inferomedially. By contrast, the EEA allowed for decompression over the medial aspect of the SOF, from the lateral opticocarotid recess superiorly to the maxillary strut inferiorly. In both patients treated using the ETOA and SOF decompression, the severity of ophthalmoplegia got obvious improvement. CONCLUSIONS: Based on the cadaveric findings, ETOA provided a feasible access pathway for SOF decompression with reliable outcomes, and our patients confirmed the clinical efficacy of the ETOA for managing tSOFS.

Optimizing the selection of the endoscopically assisted supracerebellar transtentorial approach to the medial temporo-occipital region: Clinical application of one novel grid coordinate system.

The endoscopically assisted supracerebellar transtentorial (eSCTT) approach is advocated for managing pathologies of the medial temporo-occipital region, but quantitative analysis is currently lacking. The aims of this study were to establish a grid coordinate system on the tentorium to model the anatomical relationship between medial temporo-occipital region pathology and the slope of the tentorium, and then to compare the paramedian eSCTT and extreme-lateral eSCTT approaches quantitatively. Bilateral paramedian and extreme-lateral eSCTT approaches were used to dissect three adult cadaveric heads anatomically. A grid coordinate system was established on the tentorium, and the angles of attack and depth of the surgical corridor of each coordinate point were obtained so that the two eSCTT approaches could be compared statistically. The measurements were then analyzed to determine the condition for selecting each eSCTT approach, and its clinical feasibility was assessed in three patients with large tumors in the medial temporo-occipital region. For coordinate points where the X-coordinate on the grid coordinate system was 1 cm outside the apex of the tentorium, the paramedian eSCTT approach had a significantly wider angle of attack and shorter depth of surgical corridor than the extreme-lateral eSCTT approach. In contrast, the extreme-lateral eSCTT approach was better for coordinate points where the Y-coordinate on the grid coordinate system was 1 cm in front of the apex of the tentorium. The long axis of each patient's tumor was projected on to the tentorium and its corresponding coordinate points were used to match the more appropriate eSCTT approach. Preliminary results for three patients treated with the eSCTT approach for large tumors in the medial temporo-occipital region were encouraging. When the eSCTT approach is applied to manage a large tumor of the medial temporo-occipital region, assessment of the long axis of the tumor and knowledge of the selective condition for each eSCTT approach can help in clinical decision-making.