Flexible Rhinoscopy

Flexible rhinoscopy is a quick, office-based procedure used to examine the entire nasal cavity.

It is most commonly performed by otolaryngologists in the evaluation of nasal obstruction, sinusitis, epistaxis, anosmia, other symptoms of rhinitis, and head and neck cancer. It can also be performed by allergists in the evaluation of allergic rhinitis and radiation oncologists to assess the response of malignancy to radiation therapy. Internal medicine, family medicine, and emergency medicine doctors may also use flexible rhinoscopy to evaluate patients with epistaxis or nasal foreign bodies.

Flexible rhinoscopy is commonly performed in the office or at the bedside with no specific preprocedure restrictions. An average evaluation takes less than 2 minutes and is well-tolerated by the majority of patients.

Key considerations

Nasal obstruction is a sensation that one or both nasal passages are blocked. There are many causes of nasal obstruction, and the etiology is often multifactorial. Diagnosis requires a thorough history and physical examination, with imaging reserved for surgical planning and evaluating intracranial spread or invasion into adjacent structures. Flexible rhinoscopy is a useful adjunct to the physical examination that allows direct visualization of structures within the superior and posterior nasal cavities that may not be visible with anterior rhinoscopy alone.

The differential diagnoses of nasal obstruction are considerable (see below). A thorough history, including onset, duration, current medications, and aggravating/relieving factors, can help to narrow the differential diagnoses. Constant unilateral obstruction usually results from anatomic obstruction, whereas a seasonal congestion or one that responds to topical decongestants is typically due to an inflammatory pathology. Pediatric patients can present with life-threatening respiratory distress secondary to some congenital causes of nasal obstruction; therefore, prompt evaluation and treatment is essential in these patients.

Differential diagnoses

Congenital causes of nasal obstruction include the following:

• Choanal atresia

• Pyriform aperture stenosis

• Midnasal stenosis

• Encephalocele

• Nasal dermoid

• Glioma

• Teratoma

• Nasolacrimal duct cyst

• Turbinate hypertrophy

• Septal deviation

• Neonatal rhinitis

• Vascular lesions

• Craniofacial abnormalities

Anatomic causes of nasal obstruction include the following:

• Septal deviation

• Turbinate hypertrophy

• Nasal valve collapse

• Concha bullosa

• Nasal/sinus tumor

• Nasal polyposis

• Septal perforation

• Synechiae

Inflammatory causes of nasal obstruction include the following:

• Allergic rhinitis

• Nonallergic rhinitis

• Rhinosinusitis[1]

• Rhinitis medicamentosa

Systemic causes of nasal obstruction include the following:

• Hypothyroidism

• Medications (antihypertensives, antidepressants, antipsychotics, beta-blockers)

• Rhinitis of pregnancy (rhinopathia gravidarum)

• Wegener granulomatosis

• Tuberculosis

• Sarcoidosis

• Rhinoscleroma

• Rhinosporidiosis

Flexible rhinoscopy is indicated for the thorough evaluation of any patient with nasal obstruction or any nasal complaint not fully evaluated with anterior rhinoscopy. In addition, flexible rhinoscopy is commonly used for postoperative follow-up and as an adjunct to the evaluation of head and neck cancer.

Complication prevention

Discomfort and epistaxis are the most common complications. Allowing time for adequate anesthesia can help decrease the discomfort experienced by some patients. Knowledge of the intranasal anatomy and the rhinoscope's maneuverability can decrease the length of the examination. Epistaxis can be avoided by minimizing contact with the nasal mucosa.

A flexible rhinoscope is necessary for this procedure. Numerous scopes are available, and the choice of equipment is at the discretion of the physician.  In general, pediatric rhinoscopes have a diameter of 2.4–3 mm, while adult scopes range from 3.4–4.8 mm. Length of scopes also varies, but a typical scope is 300 mm.

The end of the scope can angulate 90-130°, and the field of view is 75–110°. The light source can take the form of a portable battery-powered unit or a plugged-in source lamp. Suction equipment should also be available in case there is crusting or mucous that obscures the physician's view. An 8- or 10-Frazier suction can be used in adults, while a smaller Frazier suction or flexible catheter suction can be used in pediatric patients.

Anesthesia

Flexible rhinoscopy can be safely carried out without any systemic anesthesia. Topical 2% or 4% lidocaine (Xylocaine) is a commonly used anesthetic.[2, 3] Its onset of action is 1–5 minutes and duration of action is 15–30 minutes. Oxymetazoline (Afrin) is also commonly administered intranasally for decongestion. It may be useful to examine the native nose prior to application and then again after decongestion.[4, 5]

Positioning

Patients should be seated upright during the examination. However, if a patient is unwilling or unable to sit upright, the examination can be completed with the patient lying down.

Patients should be instructed that anesthesia following the procedure can persist for an additional half an hour. With anesthesia, the gag reflex can be diminished or absent; therefore, patients should not take anything by mouth until the anesthesia has worn off.

Complications

Patient discomfort and epistaxis are potential complications. As mentioned previously, anesthesia is not necessary, but can help reduce discomfort secondary to the procedure. The physician should also be careful to avoid abrading the nasal mucosa or disturbing any raw surfaces. If epistaxis is evoked by the procedure, oxymetazoline nasal spray should be sprayed in the nose and firm nasal pressure applied for 10 to 15 minutes. If this fails to control the bleeding and the source of bleeding is clearly visible, nasal cautery with silver nitrate can be performed. Alternatively, a hemostatic agent such as Surgicel can be applied. Nasal packing should be reserved for intractable cases. If a patient requires nasal packing, an antibiotic with gram positive coverage such as cephalexin (Keflex) or clindamycin (Cleocin) if penicillin allergic should be prescribed while the packing is in place because there have been cases of toxic shock syndrome from nasal packing.

Long-term monitoring

No long-term monitoring is necessary.

The steps of flexible rhinoscopy are described below.

• While the anesthesia is allowed to take effect, the flexible scope should be focused and adequate lighting should be confirmed

• Defog is then applied to the tip of the scope, and lubricant may also be applied to the shaft

• The scope is placed along the floor of the nasal vault

• The septum and inferior turbinate are evaluated first

• Any septal deviation or spurs should be noted

• Turbinate hypertrophy or atrophy is documented

• If the rhinoscopy is being performed for recurrent epistaxis, the Kiesselbach plexus (located on the anterior inferior septum and represents the confluence of the anterior ethmoid artery, greater palatine artery, sphenopalatine artery, and septal branch of the superior labial artery) should be carefully examined; anterior nosebleeds frequently originate from this area

• Following anterior inspection, the scope should gently be advanced posteriorly toward the nasopharynx

• Any mass should be inspected, with special attention paid to its origin and appearance, which can assist with the diagnosis[6, 7, 8, 9]

• If endoscopy is being performed for epistaxis, the area of Woodruff plexus (located at the posterior aspect of the inferior meatus) is examined;[10] this is the source for many posterior nosebleeds since it is composed of large, thin-walled veins

• The scope is taken posteriorly to the nasopharynx, where the nasopharyngeal mucosa, eustachian tube orifice, and fossa of Rosenmüller are examined

• The sphenoid rostrum may also be visualized, and the presence of purulent drainage or polyposis should be noted

• The scope is then gently withdrawn and placed above the inferior turbinate to view the middle turbinate; the size of the turbinate is noted as well as any mucosal changes, crusting, edema, purulence, or polypoid degeneration; in postoperative patients, the turbinate may be lateralized, medialized, or absent

• Synechiae can also be seen in postoperative patients

• The true maxillary ostium should be hidden behind the uncinate process, so any ostia that are visualized are likely accessory ostia

• A mass arising from the middle meatus should raise the suspicion of an inverted papilloma

• Visualization superoposteriorly is typically limited by the ethmoid complex unless the patient has had prior sinus surgery; in these cases, the ethmoid labyrinth should be examined for the presence of synechiae, polypoid degeneration, residual air cells, and any other masses/lesions

• The cribriform area should be inspected medial to the middle turbinate; this is the location of the olfactory epithelium and may be a site for neoplasms, encephaloceles, and other pathology

• The procedure is then repeated in the contralateral nasal passage

Pathology and appearance

See the list below:

• Conditions and their pathologic appearance are as follows:

• Nasal polyposis - Pale, smooth, glistening, grape like, bilateral

• Inverted papilloma - Flesh colored, unilateral, lateral nasal wall

• Malignancy - Friable, unilateral, exophytic, and/or ulcerated mass

• Wegener’s granulomatosis - Friable mucosa, ulcerated septal perforation

• Tuberculosis - Crusting, septal perforation

• Sarcoidosis - Friable mucosa, crusting, submucosal nodularity

• Rhinoscleroma - Purulent rhinorrhea, nodules, blue/red mucosa

• Concha bullosa - Enlarged middle turbinate

• Synechiae - Scar band

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Class Summary

Local anesthetics block the initiation and conduction of nerve impulses. Anesthetics used for the cystoscopy include lidocaine.

Lidocaine (Xylocaine)

Lidocaine inhibits depolarization of type C sensory neurons by blocking sodium channels. Topical 2% or 4% lidocaine (Xylocaine) is a commonly used anesthetic. Administer local lidocaine sprays into the nostril. Its onset of action is 1-5 minutes and duration of action is 15-30 minutes. One to two sprays per nostril may be applied.

Class Summary

Topical vasoconstrictors act on alpha-adrenergic receptors in the nasal mucosa, causing vessels to constrict.

Oxymetazoline 0.05% (Afrin, Dristan 12Hr, Duramist Plus, Nostrilla, Vicks Sinex 12 Hr)

Oxymetazoline is applied directly to mucous membranes, where it stimulates alpha-adrenergic receptors and causes vasoconstriction. Decongestion occurs without drastic changes in blood pressure, vascular redistribution, or cardiac stimulation.

Oxymetazoline may be used in combination with lidocaine 4% to provide effective nasal anesthesia and vasoconstriction. It may be useful to examine the native nose prior to application and then again after decongestion.

If epistaxis is evoked by the procedure, 2-3 sprays/nostril of oxymetazoline nasal spray should be sprayed into the nose and firm nasal pressure applied for 10-15 minutes.

Class Summary

If a patient requires nasal packing, an antibiotic with gram-positive coverage such as cephalexin (Keflex) or clindamycin (Cleocin) (if penicillin allergic) should be prescribed while the packing is in place, as cases of toxic shock syndrome due to nasal packing have been reported.

Cephalexin (Keflex)

Cephalexin is a first-generation cephalosporin that arrests bacterial growth by inhibiting bacterial cell wall synthesis. It has bactericidal activity against rapidly growing organisms. Cephalexin's primary activity is against skin flora; the drug is used for skin infections or prophylaxis in minor procedures.

Clindamycin (Cleocin HCl)

Clindamycin is a lincosamide used for treatment of serious skin and soft tissue staphylococcal infections. It is also effective against aerobic and anaerobic streptococci (except enterococci). It inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest.