The endonasal surgical method has recently become increasingly important in ENT practice and neurosurgery due to the possibility of endoscopic treatment of benign neoplasms of the nose and paranasal cavities, as well as the base of the skull. The accumulation of experience in the application of this surgical method and the use of angled optics has led to a significant reduction in the recurrence rate of this type of tumor.
However, two aspects of the above operating method have been criticized:
- it is very difficult or almost impossible to carry out endonasal removal of large tumors
- preparation of the lateral or cranial margins of the tumor in a healthy environment is difficult; in particular, the lateral spread of the tumor (sinus maxillaris) is difficult to reach through the endonasal pathway
Concerning the first point of criticism, experience has shown that the projections resulting from the removal of the tumor mass in parts according to histology are assessed in the same way as the projections resulting from their block resection. Thus, tumors of significant size are also amenable to endonasal surgical treatment using this method.
The solution to the second problem was facilitated by the use of angled optics (45 °), with the help of which it became possible to recognize the lateral and cranial edges of neoplasms. However, the lack of proper instrumentation was still a problem, since the existing one-fold angled instruments (45 ° or 90 °) did not allow reaching the lateral edges of the lesions due to the too-short curved part. For instruments with an elongated curved portion, insertion into the nasal cavity was difficult, if not impossible. Technical difficulties of this kind were solved by using instruments with double curvature, which makes it possible to easily insert instruments into the nasal cavity and their penetration to the lateral and cranial edges of the neoplasms under endoscopic guidance.
From an oncological point of view, it is necessary to resect the tumor mass of benign neoplasms under the mucous / periosteum level, thus it is possible to remove the tumor mass in whole or in separate fragments and avoid facial surgery. With angled optics and double-curved instruments, the tip of the instrument remains in the center of the image. This method makes it possible to remove the neoplasm (for example, inverted papilloma) by resecting the tumor mass from the periphery (mucous / periosteum of the maxillary cavity wall) to the center of the nasal cavity. This method is called "centripetal".
The surgical method of tumor removal described above is impossible without the use of double-curved angled instruments, which allow using the advantages of angled optics in all directions.