Endoscopic dissection of the infraorbital canal in patients with sinonasal inverted papilloma

Abstract

Intrоduction. Sinonasal papilloma is a benign tumor. The standard treatment for sinonasal inverted papilloma (SIP) is surgical intervention. The tumor is located primarily in the maxillary sinus (50.9 %). Sinonasal inverted papilloma originated from the maxillary sinus has aggressive characteristics and can dislodge local anatomical structures, infraorbital canal in particular.Aim. To present a descriptive characteristic of structural changes in the infraorbital canal during SIP growth and determine the optimal volume of canal dissection.Materials and methods. A retrospective study of patients with SIP was performed. From the total cohort (n = 37), 15 patients with primary localization of sinonasal inverted papilloma in the maxillary sinus were selected. In all cases, the same diagnostic algorithm was used. Separately, evaluation of infraorbital canal anatomy based on preoperative analysis of computed tomography of the paranasal sinuses and intraoperative endoscopic exam was performed. Surgical strategy used in all cases consisted of endoscopic SIP tissue removal, total resection of the mucoperiosteum and subperiosteal dissection of all walls of the maxillary sinus using a bur. During surgery material was collected for control histological examination.Results. In 20 % of cases, changes in the walls of the infraorbital canal in the form of hyperostosis, erosion and dehiscence were observed. In 13.3 % of cases, growth of sinonasal inverted papilloma caused distortions in the structure of infraorbital canal walls. In all cases, computed tomography data showed the same results as intraoperative endoscopic visualization. For removal of the lesion and pathologically changed walls of the infraorbital canal, transnasal endoscopic partial maxillectomies (type 3 or 4) were performed. Follow-up duration varied between 1 and 5 years, mean follow-up duration was 3 years. SIP resection was effective in all patients, no recurrences were observed.Conclusion. For SIPs growing in the maxillary sinus, condition of the infraorbital canal must be of special interest. The study showed the effectiveness and flexibility of the surgical strategy consisting of the combination of total mucoperiosteum resection with subperiosteal dissection of all walls of the maxillary sinus.