With the widespread adoption of nasal endoscope-assisted diagnostic and therapeutic techniques, endoscopic examination has gradually become a routine diagnostic and treatment method in rhinology. The nasal endoscope, characterized by its multi-angle capability and wide field of view, enables thorough examination of various parts of the nasal cavity and nasopharynx.
Rigid Nasal Endoscopy
A complete system for nasal endoscopy includes endoscopes with 0°, 30°, 70°, and 120° viewing angles, with lengths ranging from 20 to 23 cm. The outer diameters measure 2.7 mm for pediatric use and 4.0 mm for adult use. The setup is often equipped with irrigation and suction systems, video editing systems for image capture and processing, and powered microdebriders. Prior to use, the nasal mucosa is constricted and anesthetized with tetracaine and ephedrine, and examinations are conducted sequentially across different areas.
Nasal Endoscopy
Step 1: Observation of the anterior end and entire surface of the inferior nasal concha, as well as the inferior nasal meatus and nasal septum. A 0° endoscope is typically used, inserted along the nasal floor and inferior meatus, and advanced gradually from anterior to posterior.
Step 2: Observation of the middle nasal concha, middle nasal meatus, lateral wall of the nasopharynx, Eustachian tube opening, pharyngeal recess, and sphenoethmoidal recess. Endoscopes with 0°, 30°, or 70° angles may be used. The scope is advanced along the nasal floor to reach the posterior nasal choana, allowing visualization of the lateral nasopharyngeal wall and Eustachian tube opening. Subsequently, the scope is retracted to observe the anterior and lower edges of the middle nasal concha from the superior surface of the inferior nasal concha, and is then advanced again to examine the middle nasal meatus, frontal sinus, anterior and middle ethmoid sinuses, and maxillary sinus openings. Further advancement to the posterior end of the middle nasal concha allows visualization of the sphenoethmoidal recess, sphenoid sinus opening, and posterior sinus openings.
Step 3: Observation of the nasopharyngeal roof, olfactory cleft, superior nasal concha, and superior nasal meatus. A 70° endoscope is suitable for this purpose. The endoscope is initially advanced to the posterior nasal choana to view the nasopharyngeal roof. It is then inserted between the middle nasal concha and the nasal septum to examine the superior nasal concha and superior nasal meatus. These structures can also be visualized by inserting the scope from the posterior end of the middle nasal concha.
Step 4: Examination of the posterior nasal choana. Endoscopic examination can help identify bleeding sources in the deeper parts of the nasal cavity, detect early-stage tumors, pinpoint the site of cerebrospinal fluid leakage and skull base fractures, and collect biopsy samples or perform electrocautery under direct visualization.
Compared to conventional anterior rhinoscopy, nasal endoscopy provides superior illumination, higher resolution, and a clearer field of view. It is also mobile and capable of capturing minute structures such as the uncinate process and the frontal recess. Endoscopic imaging data can be displayed and stored immediately for reference.
Sinus Endoscopy
Maxillary Sinus Endoscopy
This method involves creating an anterior puncture in the inferior nasal meatus to access the maxillary sinus. Endoscopes with various viewing angles are inserted sequentially through a sheath into the sinus. Access via the canine fossa is another option.
Sphenoid Sinus Endoscopy
Using the posterior end of the middle nasal concha as a reference point, the sphenoethmoidal recess is located between the nasal septum and superior nasal concha. The sphenoid sinus opening is situated near the top of this recess. Appropriate expansion of its natural ostium can facilitate observation.
Frontal Sinus Endoscopy
External Brow Arch Approach
A 1.0cm horizontal incision is made along the medial aspect of the brow arch corresponding to the floor of the frontal sinus. A trephine is used to penetrate the anteroinferior wall of the frontal sinus, allowing for insertion of the endoscope.
Transnasal Ethmoid Approach
If the frontal sinus drains through the frontal recess, a 70° endoscope can locate the sinus opening at the anterosuperior region of the middle nasal concha. If it drains into the anterior superior ethmoidal cells, anterior ethmoidectomy is performed first, followed by insertion of a 70° endoscope for observation.
Flexible Nasal Endoscopy
The fiberoptic nasal endoscope, characterized by its fine diameter, can be advanced into the nasal cavity via the anterior naris under surface anesthesia. Its flexible distal tip allows access to various nasal meatuses, such as the middle nasal meatus, semilunar hiatus, uncinate process, and ethmoid infundibulum. It facilitates examination of the natural openings of the maxillary, frontal, ethmoidal, and sphenoidal sinuses and the detection of nearby lesions.