Abstract: Objective To investigate the efficacy of a 70° endoscope in the resection of maxillary sinus inverted papillomas via the prelacrimal recess approach(PLRA). Methods This retrospective analysis reviewed the clinical data of 15 cases of endoscopic resection of maxillary sinus inverted papillomas via the PLRA. All patients underwent preoperative endoscopic, CT, and contrast-enhanced MRI examinations to determine the extent of the lesions. According to the Tongren staging system, 3 cases were classified as Stage 2 and 12 as Stage 3. Under a 0° endoscope, the maxillary sinus ostium was routinely enlarged and opened; under a 70° endoscope, tumors were observed on the inferior, anterior, and posterolateral wall of the maxillary sinus, and complete resection was not possible. A prelacrimal fossa incision was made, and a 70° endoscope was used to visualize the walls of the maxillary sinus, followed by complete surgical resection of the tumor. Postoperative follow-up was conducted regularly to monitor for tumor recurrence and assess improvement in clinical symptoms. Results All 15 patients underwent the procedure. They were followed up for 3 to 36 months, with a mean follow-up of 12 months. None of the 15 patients experienced tumor recurrence postoperatively; nasal obstruction improved, and no clinical symptoms such as epistaxis, headache, diplopia, or epiphora occurred. There were no reports of facial pain and abnormal numbness. Conclusion The PLRA is the preferred method for resecting inverted papillomas whose base is located on the anterior, inferior, or anterior segment of the medial wall of the maxillary sinus. The use of a 70° endoscope allows for visualization of all walls of the maxillary sinus, providing a wide field of view that facilitates complete tumor resection, reduces the risk of recurrence, and improves clinical symptoms.

Key words: Inverted papilloma, Maxillary sinus, Prelacrimal recess, Nasal endoscopy