Flexible Nasopharyngoscopy

Anatomy and Physiology

Nasopharyngoscopy can be performed in adults, cooperative children, and babies with parental permission. It is typically done to investigate any area of concern or follow-up in a treated area (surgery/radiotherapy/chemotherapy) that is otherwise difficult to access and visualize.

As there are too many abnormalities and pathologies that are identifiable on scoping, that to mention all would be impossible. Some of the important and commoner ones are listed below.

Nasal Cavity

A three-pass technique is used to examine all areas of the nasal cavity.

• Septal deviation, bony spurs, turbinate hypertrophy
• External and internal nasal valve areas
• Nasal obstruction, mucopurulent debris, sinus drainage, mucosal edema
• Bleeding points, septal perforations
• Polyps, adhesions, and crusting 

Posterior Nasal Space

The Eustachian tube orifices, fossa of Rossenmuller, and adenoidal pad are inspected.

Adenoids should regress in adulthood, and prominent adenoids warrant investigation. Any untoward mass seen should be further investigated.   

The Base of Tongue and Valleculae

The base of tongue and valleculae are inspected for any masses, cysts, or irregularities. Lymphoid tissues of the lingual tonsils can be found here and often account for the irregularity seen. Any untoward mass seen should be further investigated, as this is a common site for oropharyngeal squamous cell carcinoma.

Epiglottis

In children, abnormalities of the epiglottis (omega-shaped) and aryepiglottic folds can be seen in laryngomalacia.[2]

Epiglottitis is a contraindication for scoping, unless done in experienced hands in a stabilized patient in an appropriate environment, due to the risk of laryngospasm and airway deterioration. 

Piriform Fossae

Any pooling of saliva, fullness, or masses seen here requires further investigation.

Larynx

Abnormalities of the arytenoids, if any, should be inspected.

Vocal cord movements, swelling, edema, masses, or mucosal changes also require examination. Any stridor or airway concerns again need to be scoped in a safe environment and experienced hands, with support from the anesthetists.

Indications

The majority of scope investigations occur in the hospital setting for acute assessments of the airway, persistent hoarseness, globus sensation, recurrent epistaxis, and tumor/cancer investigation and surveillance. In addition to this, the other main indications are listed below:[3][4][5][6]

1. Removal of a foreign body that is easily accessible
2. Evaluation of obstructive sleep apnea, e.g., the Muller maneuver, although it is still difficult to evaluate from this the patients that will do well with surgery.
3. Velopharyngeal insufficiency
4. Examining the acute airway and establishing if patients require intensive therapy unit (ITU) care or airway management
5. Fibre endoscopic evaluation of swallowing (FEES) done in association with the speech and language therapists in patients with swallowing problems
6. Vocal cord office-based injections for vocal cord palsies
7. Tracheoscopy

Contraindications

There are few contraindications for flexible nasopharyngoscopy. The main two are acute epiglottitis and croup. In epiglottitis, there is an actual risk of sending the patient into laryngospasm, so this needs to be left to an experienced ENT surgeon to perform the procedure if required.[7] Relative contraindications include coagulopathies, which may result in significant bleeding and craniofacial trauma where inadvertent intracranial instrumentation can occur.

Equipment

• Flexible nasopharyngoscope - fibreoptic or digital chip-on-the-tip technology; the size of scope diameter varies from 1.9 mm (pediatric) to 6 mm (adult)
• A viewing camera can be attached to the viewing port of the scope (if not a digital scope)
• A light source (can be portable) 
• Light lead (if required)
• Screen/monitor with picture acquisition and an image printer
• A decontamination system for scopes: a disposable endoscopic sheath; chlorine dioxide multi-wipe system; endoscope washer-disinfector units
• Topical decongestant/anesthetic spray
• Lubrication gel
• Alcohol wipes
• Tissues

Personnel

• ENT surgeon
• Maxillofacial surgeon
• Speech and language therapists (fiberoptic evaluation of swallowing)

Technique or Treatment

Step 1: Before you start

• A clean scope is required for this procedure.
• Check that the nasopharyngoscope is in good working order and that contact tracing for the scope is in place. There are different decontamination systems available for cleaning of the scopes, as previously mentioned, this depends on local hospital policies. Appropriate cleaning and disinfection guidelines and general principles for infection prevention will already be in place in your department. [8] These can be accessed on request. 
• The operator should check the indications for scoping and confirm the procedure is appropriately being undertaken. Often, with oncology patients, previous changes may have been documented and these images should be reviewed.
• Often patients are apprehensive about having an endoscope inserted into their nostrils. Reassure them that this is a minimally invasive procedure that although uncomfortable it is not usually painful, is quickly done, and gives invaluable information. 
• A topical spray like co-phenylcaine (lidocaine and epinephrine) or xylometazoline can be used to help decongest and anaesthetize the nose to make the passing of the endoscope easier and less painful. It can take a few minutes for the spray to take effect. The spray also does reduce the gag reflex which helps to give a stable image during scoping. The patient needs to be warned about the bitter taste and the abnormal feeling of an anaesthetized throat. This sensation takes about 1 hour to wear off during which time they should not eat or drink.

Step 2: Preparing to pass the nasopharyngoscope

• Verbal informed rather than written consent is usually adequate for this outpatient procedure. 
• Check the clarity and focus of the image by using a label or writing.
• Explain the procedure and the manoeuvres that will be undertaken. These manoeuvres can help identify important and hidden anatomy during the scoping. 
• Ask which nostril is more patent. Spray the nose if required. 
• Sit upright, 'sniffing the morning air' position, with head support. 
• Lubricate the scope.
• Wipe the tip of the scope with an alcohol wipe or on the patient's tongue to prevent fogging. 
• The operator will be either looking directly down the scope or watching a monitor.

Step 3: The Examination

• Gently insert the scope into each nostril.
• Foreign bodies can be removed with handheld forceps using the scope for visual guidance. [9]
• Examine the nose, posterior nasal space, the base of tongue, pharynx, and larynx methodically. Looking for normal and abnormal anatomy.
• The patient is then asked to do several manoeuvres to aid in visualization:

• • "Sniff in" - opens up the nasopharynx and allows the scope to be advanced easily beyond the nasopharynx
  • "Stick your tongue out" - opens up the vallecular region at the base of the tongue often a place where base of tongue cancers hide
  • "Blow your cheeks out" or "turn your head to the right and left shoulders" - opens up the piriform fossae again often a hiding place for cancers
  • "Say Eeee" or "Count to 10 aloud" - causes abduction of the vocal cords, breathing in should have the opposite effect and abduct the cords equally
  • "Swallow please" - allows any blood or mucous to be dislodged from the tip of the scope if it is causing poor visualization

Step 4: Aftercare 

• Some patients feel lightheaded and should remain seated until this passes
• The patient should refrain from eating and drinking for 1 hour
• Nose bleeds and coughing are temporary if they occur and only last for a minute or two

Step 5: Post-procedure 

• Appropriate documents are completed to allow contact tracing and the correct tariffs to be applied (often nasopharyngoscopy attracts its own tariff)
• Contact tracing with appropriate labels are placed in the case notes
• Diagrams and Pictures are appropriately annotated and stored, with patient identifiers, so that another practitioner looking at them can understand the findings

Complications

The following represent some of the possible comlications[10][11][12]:

• Although complications are rare, the most common are sneezing, and mucosal tearing and bleeding secondary to injury - to prevent this, adequate nasal decongestion and limited force should be used
• Laryngospasm, a serious risk, although reported in less than 1% of procedures
• Gagging and adverse reaction to the nasal decongestant are other potential risks
• Damage to anatomic structures is more common with the use of rigid scopes, and rarely seen with flexible scopes

Clinical Significance

Flexible nasopharyngoscopy and fiberoptic imaging have revolutionized ENT outpatient clinics. Technology has moved further forward with the new chip-on-the-tip digital flexible scopes. This method is a far cry from the ENT doctors using indirect laryngoscopy with hand-held mirrors and head mirrors.

In a typical head and neck cancer clinic, nearly all patients will have a flexible nasopharyngoscopy to look at cancer surveillance, treatment response, or disease recurrence. In the acute setting, it is also used very often, for example, in all airway concerns or neck abscesses. It has become a routine tool in the ENT surgeon's armament, as common as using an otoscope, and one that is used regularly.

Enhancing Healthcare Team Outcomes

Interpretation and ability to carry out flexible nasopharyngoscopies remains a skill and a learning curve. Although the ENT surgeon does these procedures daily, and so their learning curve is much faster, other related specialists, including anesthesiologists, nurse anesthetists, and the pulmonologists, can use this tool and quickly pick up the expertise also. New gadgets used in stroboscopy, digital chip-on-the-tip technology, and endoscopic smartphone adapters keep the technology moving forward.[13][14][15]