The Nasal Endoscope
Endoscopy is a minimally invasive, diagnostic medical procedure. It is used to examine the interior surfaces of an organ or tissue and allows visualization of body cavities not possible by standard examination. The nasal endoscope is a medical device consisting of a thin, rigid tube with fiberoptic cables for illumination. The endoscope is then connected to a light source and a video camera to project the images on a monitor. These endoscopic images can be captured and recorded for documentation for each patient. In some nasal endoscopes, the goal is to look straight from the tip of the instrument into the nose; there are other endoscopes in which the desired view is at an angle from the tip of the telescope. These 'angled' endoscopes can be used to see around corners and into the curved sinus cavities. Because the endoscope is so slender (only 2.7-4.0 mm in width), it may be passed easily through the nostril to examine the nasal passages, structures and sinuses. While the traditional nasal examination with a speculum and a flashlight (termed anterior rhinoscopy) allows a limited “key-hole” view of the front part of the nose, the endoscope allows a direct view of the deeper internal anatomy, central airway and posterior aspects of the nose and sinuses.
Office nasal endoscopy allows a detailed examination of the nasal and sinus cavities. This examination is typically performed by otolaryngologists (Ear Nose Throat doctors). It is currently the preferred initial method of evaluating medical problems such as nasal stuffiness and obstruction, sinusitis, nasal polyps, nasal tumors, and epistaxis (nose bleeds). During the endoscopy, the physician or other certified provider can search for: areas of swelling in the mucosal membranes; presence of purulent secretions draining from the sinus openings; enlargement of the nasal turbinates; crooked contouring to the nasal septum; presence of polyps; sites of nasal bleeding; and the presence of tumors. If pus is seen, it may be sampled and cultured with a fine swab to determine what organism is causing the infection.
Just before nasal endoscopy, the nose will be sprayed with: 1) a topical decongestant, to gently reduce the swelling in the nasal membranes to permit the endoscope to pass easily, and 2) a topical anesthetic, which temporarily numbs the nose and helps to decrease the chances of sneezing from sensitivity. The procedure is rarely painful, but some patients may experience discomfort if the nasal cavity is unusually narrow or the nasal lining is very swollen. Additional numbing spray or a pediatric –sized endoscope may prevent such discomfort.
Nasal endoscopy can also be used to visualize suspicious nasal lesions and enable a biopsy, or for finding and retrieving foreign objects caught inside the nose. In these cases a spectrum of fine instruments may be used to perform these tasks. These instruments are specially designed for use in the nose and sinuses during nasal endoscopy, and the otolaryngologist is typically quite skilled in simultaneously using both the endoscope and nasal instruments. Some of these instruments are curved, which makes it possible to reach around corners within the nose. The latter instruments are commonly used with 'angled' endoscopes. They may be used both in the operating room and even in the office when your otolaryngologist performs routine surveillance.
Nasal Endoscopy in the Operating Room Endoscopic sinus surgery using nasal endoscopes is currently the preferred alternative for managing sinus infections that are refractory to medical treatments, complications of sinus infections, nasal polyposis, intractable epistaxis, CSF (brain fluid) leaks, sinus fungal balls, and even some nasal/sinus tumors. Recently the nose and the sinuses are being utilized as a corridor to approach territories in the anterior and middle skull base (where the nose meets the brain), the intracranial cavity, the inner parts of the orbits, and even the upper part of the spine. Through this specialized method, patients can undergo necessary surgery often without facial or scalp incisions, to remove lesions completely and reverse disease processes. The endoscopic transnasal approach has also gained widespread popularity for resection of pituitary tumors. These types of procedures are performed by a specialized group of otolaryngologists and neurosurgeons who have undertaken advanced training in these procedures and work well together as a team. Endoscopic trans-nasal approaches are also being applied to orbital (eye socket) procedures. The endoscopic dacrocystorhinostomy (DCR) procedure for treating tear drainage problems, is gaining general acceptance. This type of surgery would be performed by an otolaryngologist and ophthalmologist skilled in this technique.
Image Guidance Navigation Surgery
Although the optics and clarity during nasal endoscopy are excellent these days, still an inherent limitation to endoscopic nasal surgery is the two-dimensional view afforded by the use of the single lens on a monitor. Navigational systems were developed to help reduce the already-low risks with endoscopic sinus surgery. These systems use specialized CT or MRI scans that are reformatted to create a three-dimensional configuration of any patient’s scan. This 3-D view is then aligned to each individual patient’s facial anatomy during surgery with the help of advanced computer software. Using image guidance technology, the surgeon can confirm his/her location within the sinus cavities using a pointer to get an accurate, 3-D view of the surgical landscape; this is similar to how GPS (global positioning system) works with maps to assist the user with directions. These computer-assisted navigation systems can be extremely helpful for difficult cases, revision surgery and combined otolaryngology-neurosurgery procedures mentioned earlier.