[Possibility and limits of the endonasal approach in sinonasal inverted papilloma cases--the technique and own experience. Preliminary report].

The aim of this article is to present the technique of endonasal operation due to sinonasal inverted papilloma with it's limitations. Material consists of 21 patients operated with microscope and endoscopes. The tumor is resected in few pieces, but I try (especially in the beginning) to keep the resected tumor as much as possible in one part--which makes easier to assess the tumor borders. Mostly it is possible to leave at place the inferior turbinate and only the upper part of it must be resected with the tumor. Involvement of the frontal sinus is the contraindications for a purely endonasal approach, but this involvement must be assessed intraoperatively, due to preoperative CT scan limitations. Tumor involving the orbit is also contraindication to endonasal approach. Tumor is resected with anterior or total ethmoidectomy, because of coexistence of inflammations in sinuses. It is possible to resect tumor from all ethmoid cells and both sphenoid sinuses from endonasal approach. Mostly it is possible to resect tumor from maxillary sinus from endonasal approach. I leave a healthy mucosa of the maxillary sinus and resect only tumor and the margins. But in the case of prelacrimal recess involvement of the maxillary sinus or difficulty with removing tumor from the bottom of the sinus I open it through the Caldwell-Luck approach (2 cases). Postoperative cavity usually heals very well. In the presented material I didn't observed recurrence of the tumor and the patients are very well (17 patients: 1-4.5 years of observation, 4 patients: under 1 year of observation). Advantages of the endonasal method are: small bleeding, operation under magnification, good view around the corner in 70 degrees endoscope, leaving anterior bony wall of the maxillary sinus, leaving inferior turbinate and small post-op. disturbances, relatively small op. injury and quick healing, possibility of removing the tumor from the nose, ethmoidal and sphenoidal and maxillary sinuses (mostly), possibility to extend the operation with external approaches if needed. Disadvantages and limits of the method are: not possible to remove the tumor from frontal sinus, difficulty in removing the tumor from prelacrimal sac recess (sometimes combined approach needed).