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 bringing in light. The endoscope is then connected to a light source and a video camera to project magnified images on a screen. These endoscopic images can be captured and recorded for documentation for each patient.
Because the endoscope is slender (only 2.7-4.0 mm in width), it may be passed through the nostril to examine the nasal passages, structures and sinuses. While the traditional nasal examination with a speculum and a flashlight (called anterior rhinoscopy) allows a limited “key-hole” view of the front part of the nose, nasal endoscopy,with its superior light and magnification, provides a superior detailed look at the deeper internal nasal anatomy, central airway and posterior aspects of the nose and sinuses. In addition, maximal visualization of the nasal and sinus cavities is provided by the various types of nasal endoscopes. The zero degree nasal endoscope allows a straight view from the tip of the instrument into the nose. The 'angled' (30/45/70 degree) endoscopes, in which the view is at an angle from the tip of the endoscope, provide an ‘around the corner’ view, deep into the sinus cavities. These superior visualization capabilities enabled by nasal endoscopy, have turned this procedure into the ‘working horse’ in the diagnosis and management of nasal and sinus conditions.
Office nasal endoscopy allows a detailed examination of the nasal and sinus cavities in the outpatient clinics. 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 patient is seated and the physician or other certified provider searches for: areas of swelling in the mucosal membranes, presence of purulent secretions (pus) draining from the sinus openings, enlargement of the nasal turbinates (internal nasal structures that humidify the nose), crookedness of the nasal septum(the wall that separates the two sides of your nose); presence of polyps; sites of nasal bleeding; and the presence of tumors within the nasal and sinus cavities. If pus is observed, it may be sampled and cultured with a small swab to determine what organism is causing the infection.
Typically, nasal endoscopy is performed with a 30 degree endoscope using the “three pass” technique, visualizing three main areas in the nasal and sinus cavities. In the first pass the nasal floor and the nasopharynx are viewed. The endoscope is then brought out and turned upwards and sideways in order to view the drainage areas of the nasal sinuses (middle and superior meati and the spheno-ethmoidal recess). In the third pass the endoscope is used to view the roof of the nose and the area of the olfactory cleft (smell region).
In order to make this procedure easier and minimize patient discomfort, just before nasal endoscopy the nose will be sprayed with: 1) a nasal decongestant, to gently reduce the swelling in the nasal membranes to permit an easy passage of the endoscope, and 2) a local 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.
Overall, nasal endoscopy is a safe and low risk procedure. Nonetheless, potential complications such as mucosal trauma and bleeding may occur, particularly in susceptible patients with increased risk of bleeding, such as those receiving aspirin or other anticoagulant medications (i.e. Plavix, Coumadin, etc.). In addition, adverse reactions to the topical decongestants or anesthetic provided prior to the procedure may occur. Thus before administering these topical medications, patients’ allergies should be verified.
See the American Rhinologic Society's position statement on nasal endoscopy.
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. Often, nasal endoscopy and cleaning of the nasal and sinus cavities is performed in the weeks following sinus surgery in order to maintain the opening of these cavities. In these cases a variety of small instruments such as suctions and various types of forceps (grasping 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. These types of 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 and inflammations that are not responding to medical treatments, complications of sinus infections, nasal polyps, persistent nosebleeds, 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 (brain and brain envelopes), the inner parts of the orbits (eye sockets), 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. This endoscopic trans-nasal approach has specifically gained widespread popularity for resection of pituitary tumors. In these procedures surgery is performed by a specialized group of otolaryngologists and neurosurgeons who have undertaken advanced training in these procedures and work well together as a team. In addition endoscopic trans-nasal approaches are also being applied to orbital (eye socket) procedures such as the endoscopic dacrocystorhinostomy (DCR) procedure for treating tear drainage problems and orbital decompression for exophthalmos. 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 view 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.