**4. The procedure**

As previously said, the systematic method of FEES evaluation is reported elsewhere in this book. In the following paragraph, there is only a reference to the main steps of the evaluation that are summarized in Table 2. The most important step, in the endoscopic procedure, is the evaluation of the correlations existing between the morphological and functional findings; a few considerations follow. What must be remembered is that the anatomy influences the function, and the function influences the behavior of the structure to the passage of the bolus. In other words the safe functioning of the effectors of swallowing can be inferred evaluating the anatomical shaping of the effectors and the ability of the structure to support the passage of the bolus through the pharynx subsequently inferred by their functional abilities.


**Table 2.** Main parameters of anatomical and functional assessment.

Sensation is a crucial factor, strongly influencing the safe passage of the bolus through the cavities. A copy of the peripheral sensation is sent in parallel to the cortex and to the brainstem, to coordinate the neuro-motor activity of the muscular effectors of the oral cavity, pharynx and supra-hyoid muscles. Table 3 and Fig.1 represent the central and peripheral interaction between sensation and motor activities.

**4. The procedure**

74 Seminars in Dysphagia

Morphological

Functional

Motor activities

Pooling dry swallows

As previously said, the systematic method of FEES evaluation is reported elsewhere in this book. In the following paragraph, there is only a reference to the main steps of the evaluation that are summarized in Table 2. The most important step, in the endoscopic procedure, is the evaluation of the correlations existing between the morphological and functional findings; a few considerations follow. What must be remembered is that the anatomy influences the function, and the function influences the behavior of the structure to the passage of the bolus. In other words the safe functioning of the effectors of swallowing can be inferred evaluating the anatomical shaping of the effectors and the ability of the structure to support the passage

of the bolus through the pharynx subsequently inferred by their functional abilities.

Epi-pharynx (soft palate) Meso-pharynx (tongue base) Hypo-pharynx (larynx)

**EVALUATION SITE**








Sensation - Reaction to the endoscope

**Table 2.** Main parameters of anatomical and functional assessment.


**Table 3.** Central and peripheral interaction between sensation and motor activities.

The stimulation of sub-glottic receptors may possibly act as a signal for the central nervous system that the larynx is "ready" (that is protected) for the bolus passage into the pharynx and this signal may, at the same time, influence the low motoneurons of the brainstem innervating Figure 1

Interaction of subglottic pressure among respiration, deglutition and phonation.

**Figure 1.** Interaction of subglottic pressure among respiration, deglutition and phonation.

the pharynx ("on line" processing) [31]. As a result of the neuro-anatomical connection between subglottic receptors and motor neurons for pharynx and larynx, the feedback from subglottic receptors may presumably affect the recruitment of motor neurons in the brainstem capable of activating the pharyngeal muscles during swallowing so that the force, speed and duration of the muscular contractions are regulated by the closing of the larynx. This feedforward system may detect that a sensory input (subglottic pressure) has not been received and control a function (swallowing) by increasing the cortical processing thereby ensuring a safe passage of the bolus into the esophagus. Cortical processing would thus account for a prolonged muscular contraction [32].

### **5. New ways to conceive endoscopy**

As previously mentioned, the role of VFSS as the instrumental gold standard, has been questioned. This in relation to the possibility of a direct endoscopical evaluation of the oral and esophageal stages of swallowing [22].

Oral FEES (O-FEES) and the esophageal FEES (E-FEES) have been introduced. The E-FEES is possible by means of the introduction of a 70 cm endoscope into the esophageal cavity (endoscope in deep position) (Table 4). In this stage the procedure, with the same morpho‐ logical and functional goals of FEES for the pharynx, has been known since 1994 (trans-nasal pharyngo-esophago-gastroduodenoscopy: T-EGD) [33]. Later Hermann first performed the test with bolus [34]. With shorter instruments, and where the study of the stomach or duode‐ num is not required, a trans-nasal examination of the esophagus is possible (trans-nasal esophagoscopy – TNE). TNE as a procedure also used for many years in the instrumental evaluation of patients with ENT complaints [35]. In a short time it became an office practice, performed on outpatients without anesthesia. Several protocols have been proposed [36-38] for patients with bolus or other complaints of gastroesophageal reflux diseases. The application of the procedure in patients with voice problems or other signs of laryngopharyngeal reflux (LPR) and swallowing disorders is limited [39]. The procedure allows for a perfect viewing of the esophageal wall and its movements, up to the cardias and of the functioning of the esophageal sphincters. With the tip of the endoscope in a retrograde position, retracting the instrument close to the upper part, a direct back viewing of the upper esophageal sphincter and its dynamics during different tasks (swallowing, belching, Valsalva) is possible. TNE also permits the evaluation of the role of saliva, bile and gas during swallowing and digestion, aside from testing the effects of reflux on the upper digestive and respiratory tracts. Finally, it allows for the proper placement of catheters before functional pharyngeal or esophageal assessment [22, 34].

The term E-FEES could be used in similarity to the new term of O-FEES, proposed for the endoscopic evaluation of the oral stage of swallowing.

the pharynx ("on line" processing) [31]. As a result of the neuro-anatomical connection between subglottic receptors and motor neurons for pharynx and larynx, the feedback from subglottic receptors may presumably affect the recruitment of motor neurons in the brainstem capable of activating the pharyngeal muscles during swallowing so that the force, speed and duration of the muscular contractions are regulated by the closing of the larynx. This feedforward system may detect that a sensory input (subglottic pressure) has not been received and control a function (swallowing) by increasing the cortical processing thereby ensuring a safe passage of the bolus into the esophagus. Cortical processing would thus account for a

**Figure 1.** Interaction of subglottic pressure among respiration, deglutition and phonation.

OESOPHAGUS

Oesophagoglottic reflex

Interaction of subglottic pressure among respiration, deglutition and phonation.

DEGLUTITION

P subglottic Subglottic Receptors

Larynx protected

Force, speed, duration of muscle contraction

Oral cavity

Bolus: chewing, formation, propulsion

Pharyngeal, Suprahyoid muscles

As previously mentioned, the role of VFSS as the instrumental gold standard, has been questioned. This in relation to the possibility of a direct endoscopical evaluation of the oral

Oral FEES (O-FEES) and the esophageal FEES (E-FEES) have been introduced. The E-FEES is possible by means of the introduction of a 70 cm endoscope into the esophageal cavity

prolonged muscular contraction [32].

LARYNGEAL SPHINCTER

=

PHONATION

Pitch Loudness

BREATHING

Figure 1

76 Seminars in Dysphagia

Lung volumes

Respiratory phase

**5. New ways to conceive endoscopy**

and esophageal stages of swallowing [22].

O-FEES is performed using an endoscope with a reversible tip of 180°, starting from a position intermediate between the high and low (in relation to the anatomy of the patient). In this position it is possible to intercept the soft palate and introduce the tip of the instrument into the oral cavity (*anterior position or retrograde position*) (Fig. 2). From this position, it is possible to see an inverted image of the oral cavity and its content, up to the teeth and lips, if kept open. With the tip retroflexed and by retracting the endoscope by a few centimeters (*anterior posterior position*) (Fig. 3), the coana with the instrument emerging from the nasal cavity, can be seen. The glosso-palatal port is, thus, visible in a dorsal viewing. Even from the tip in these positions, it is possible to obtain static (anatomical) and dynamic (phono-articulatory) information and test sensation. More information is collected during the bolus tests: bolus preparation (Fig. 4) and propulsion (Fig. 5) can be checked directly, as well as bolus entering into the pharyngeal cavity. Any kind of consistency can be tested, checking oral preparation and propulsion. The passage of the bolus through the fauces is not visible, because of the presence of the white-out, as happens during pharyngeal transit as viewed with the tip in the high position. After the tests with bolus and with the tip in the anterior position, the presence and location of residue (on the hard palate, gums, alveoli, tongue) can be verified (Fig. 6) [22].

With O-FEES and E-FEES variations, the functional assessment of the effectors of swallowing is complete. A trace of the functional assessment is reported in Table 4.


**Table 4.** The main steps of the anatomo-functional evaluation

Also the tests with bolus can be modified and enriched by O-FEES and E-FEES, as synthesized in Table 5. (UEP: upper esophageal sphincter; LES: lower esophageal sphincter)

**Static evaluation Dynamic evaluation Sensation**

Velo-pharyngeal sphincter : - Velum deviation - Gap of closure - /s/ forced *Deglutition* - Nasal regurgitation






*General of the area:* - Reaction to the endoscope - Reaction to light touch of structures

*General of the area:* - Reaction to the endoscope - Reaction to light touch of structures - Gag reflex (base of tongue)

*General of the area:* - Reaction to the endoscope - Reaction to light touch of structures


*General of the area:* - Reaction to the endoscope - Reaction to light touch of structures


*General of the area:* - Reaction to the endoscope - Reaction to light touch of: . Aryepiglottic folds . Arytenoids . True vocal folds . False vocal cords *Pooling* - Perception - Cleaning efforts - Cleaning effectiveness

*General of the area:* - Reaction to the endoscope

*Pooling* - Perception - Cleaning efforts - Cleaning effectiveness

*Pooling* - Perception - Cleaning efforts - Cleaning effectiveness

*Speech*

*Speech*

. /l/ ball . /k/ cocco

*Speech*

*Speech*

*Speech* - Glottic closure: . /a/ strained . /a/ repeated

. /a/ strained . /a/ repeated - Glottic opening: . Sniff - Vocal quality *Sphincterial activities* - True vocal cords closure: /a/ strained (time) - False vocal cord closure:

. /a/ forced . Glide up /ee/ . Valsalva . Cough - Epiglottis inversion: . Dry swallows

*Sphincterial activities* - UES . Valsalva . Cough . Belching . Dry swallows - LES *Muscular activity* - Body

. /e/ strained . /e/ repeated *Deglutition (dry swallowing)* - Base of tongue movements - Pharyngeal movements

**Endoscope position**

78 Seminars in Dysphagia

*HIGH (meso-pharynx)*

*ANTERIOR (retrograde) (oral cavity)*

*ANTERIOR POSTERIOR (oral cavity)*

*LOW (hypo-pharynx)*

*DEEP (esophagus)*

*NASAL-RHINOPHARYNGEAL (naso-rhino-pharynx)*

*Morphology of:* - Nasal cavities - Rhinopharynx

*Pooling site:* . Nasal cavities . Rhynopharynx . Tubal ostium

*Morphology of:* - Base of tongue - Pharyngeal wall

*Pooling site:* . Valleculae . Pyriform synus . Post-pharyngeal wall . Retro-cricoidal space

*Morphology of:*

*Morphology of:* - Base of tongue - Soft palate (superior face) - Glosso-palatal seal - Coana *Pooling site:* . Hard palate . Tongue: body, base

*Morphology of* - Hypo-pharynx - Larynx during respiration - Pathological muscular activities

*Pooling site:* . Sopra-glottic . Glottic . Sub-glottic . Cervical trachea

*Morphology of* - UES - Body - LES

**Table 4.** The main steps of the anatomo-functional evaluation





. Tongue: tip, medium, base


**Table 5.** Main sensory motor events of swallowing induced by the bolus [22, modified] rotated 180° to obtain viewing equal to the real one and make the images more easily interpretable).

Figure 3 Antero‐posterior position: the soft palate is lifted from the base of the tongue or lowered. **Figure 2.** Anterior or retrograde position: the oral cavity is directly visible (all the following photographs have been rotated 180° to obtain viewing equal to the real one and make the images more easily interpretable).

Figure 3 Antero‐posterior position: the soft palate is lifted from the base of the tongue or lowered.

Figure 2 Anterior or retrograde position: the oral cavity is directly visible (all the following photographs have been

rotated 180° to obtain viewing equal to the real one and make the images more easily interpretable).

**Figure 3.** Antero-posterior position: the soft palate is lifted from the base of the tongue or lowered.

Figure <sup>5</sup> Anterior position: bolus propulsion. **Figure 4.** Anterior or retrograde position: bolus preparation. Figure <sup>5</sup> Anterior position: bolus propulsion.

**Figure 5.** Anterior position: bolus propulsion.

**Figure 6.** Anterior position: tongue clearing of material coating the oral cavity.

Figure 2 Anterior or retrograde position: the oral cavity is directly visible (all the following photographs have been

rotated 180° to obtain viewing equal to the real one and make the images more easily interpretable).

Figure 3 Antero‐posterior position: the soft palate is lifted from the base of the tongue or lowered.

80 Seminars in Dysphagia

**Figure 3.** Antero-posterior position: the soft palate is lifted from the base of the tongue or lowered.

Figure <sup>5</sup> Anterior position: bolus propulsion. **Figure 4.** Anterior or retrograde position: bolus preparation. Figure <sup>5</sup> Anterior position: bolus propulsion.

**Figure 5.** Anterior position: bolus propulsion.

### **6. Endoscopy with a whole clinical context and severity**

Figure 6 Anterior position: tongue clearing of material coating the oral cavity.

Returning to our topic, it can be assumed that those parameters that express inefficient or unsafe swallowing are markers of severity: respectively residue and false routes (airway invasion). An efficient and safe swallowing expresses the perfect balance between events that occur in the domain of time and space, domains in which vector forces guarantee that defensive strategies are put in place to protect the airways, or cleanse the containment cavities from the bolus passing through them [40]. The anatomo-functional evaluation and the tests with bolus, resumed earlier, offer several points for reflection. Residue or material pooling into cavities (before or after the tests with bolus) are powerful indicators of disturbed swallowing, predis‐ posing the patient to airway invasion [41]. Material pooling and residue were used to develop scores, variously used in clinical practice. There are several scores in the literature, with severity criteria divided into 4 or 5 levels and this division does not seem to interfere with the inter-intra rater reliability of those scores [42, 43]. In 2008 the P-score was introduced [44]. In the development of this score, pooling is considered in a broader sense, as any material that is present in the containment cavities of the hypo-pharynx and larynx, before and after the act of swallowing. The severity criterion proposed by the score (Table 6) takes into account anatomical parameters: site, identified by anatomical landmarks; amount: determined in a semi-quantitative way by the amount of pooling materials (coating, more or less than 50% of cavity containment capacity); management, as well as the efficiency of secretion management, considering the number of dry swallowings performed by the patient, either spontaneously or upon request of the clinician involved in the assessment. The effectiveness of gargling, throat clearing or coughing is considered in the same way.

In clinical practice, the P-score may be integrated with other parameters of the clinical swallowing evaluation (CSE), that are more easily determined: age, sensation of the pharynx, patient collaboration. These parameters are considered in the P-SCA score (pooling-sensation, collaboration and age score) as those able to mitigate the severity criteria expressed by the endoscopic evaluation alone (see earlier and [44]). The inter-rater and intra-rater reliability of the P-score has recently been determined [40]. Four judges with long-standing experience in the use of endoscopy, and after a training session, evaluated 30 films (the pharyngeal transit of boluses with different consistency) of 23 subjects with swallowing disorders. The films, randomly recorded on two different CDs, were viewed three times: a first time, after 24 hours and after 7 days. Inter and intra-rater reliability was calculated through the intra-class correlation coefficient ICC(3,k) individually for site, amount, management and the total score. As for the items site, amount, management and total P-score, the ICC(3,k) was 0.999, 0.997, 1.00, and 0.999, respectively. The analysis of variance showed no statistically significant dependency determined by the consistency in the differences detected.

As regards the domains previously mentioned, we have that in the time domain, the score may identify events that occur before or after swallowing; indeed, part of the material pooling that has not been swallowed during the previous swallow, becomes a bolus for the next swallow, with a different volume. The P-score considers the sequence of swallowing in the "manage‐ ment", evaluating the fate of a bolus that persists in the pharynx after five empty swallows. In the space domain, where forces are in action, the P-score identifies the pathway and the flow of the bolus: the pathway is identified by the direction along the digestive or respiratory tracts, as well as false route (penetration or aspiration); the flow is indicated by the amount of bolus that does not cross the pharynx while swallowing.

The events that occur in these domains together with vectorial forces, may be integrated in different ways, generating a very wide range of possibilities. For instance, the dynamic vectors and volumetric aspects, considered by the score, allow for information to be obtained on the reaction of the patient to airway invasion (management): the occurrence, or absence, of dry swallowing, cough or throat clearing, in response to the transit of the bolus in the larynx or in the cervical trachea before, during or after swallowing is considered.


**Table 6.** P-score and P-SCA score

The P-score expresses, as a numerical value, a continuum of severity that in clinical practice may be used in different ways, with correlations that still have to be verified (Table 6). Therefore, a minimum score (P-score 4\_5) may indicate the absence of endoscopic signs of dysphagia. A low score (P-score 6\_7) may identify mild dysphagia, a medium score (P-score 8\_9) moderate dysphagia, and a high score (P-score 10\_11), severe dysphagia. The score refers to a specific type of consistency and volume, and may change according to these. A similar subdivision can be made for the P-SCA score (for more details see [44]). In this way, it is possible to give clear indications with reference to treatment, or make comparisons before and after treatment.

Anatomical landmarks and bedside parameters with relative values.

P: pooling P-SCA: pooling \_ sensation, collaboration, age

*P score:*

randomly recorded on two different CDs, were viewed three times: a first time, after 24 hours and after 7 days. Inter and intra-rater reliability was calculated through the intra-class correlation coefficient ICC(3,k) individually for site, amount, management and the total score. As for the items site, amount, management and total P-score, the ICC(3,k) was 0.999, 0.997, 1.00, and 0.999, respectively. The analysis of variance showed no statistically significant

As regards the domains previously mentioned, we have that in the time domain, the score may identify events that occur before or after swallowing; indeed, part of the material pooling that has not been swallowed during the previous swallow, becomes a bolus for the next swallow, with a different volume. The P-score considers the sequence of swallowing in the "manage‐ ment", evaluating the fate of a bolus that persists in the pharynx after five empty swallows. In the space domain, where forces are in action, the P-score identifies the pathway and the flow of the bolus: the pathway is identified by the direction along the digestive or respiratory tracts, as well as false route (penetration or aspiration); the flow is indicated by the amount of bolus

The events that occur in these domains together with vectorial forces, may be integrated in different ways, generating a very wide range of possibilities. For instance, the dynamic vectors and volumetric aspects, considered by the score, allow for information to be obtained on the reaction of the patient to airway invasion (management): the occurrence, or absence, of dry swallowing, cough or throat clearing, in response to the transit of the bolus in the larynx or in

**Bedside parameters**

Presence = - 1 Absence = +1

The P-score expresses, as a numerical value, a continuum of severity that in clinical practice may be used in different ways, with correlations that still have to be verified (Table 6).

Amount +3 (>75)

**Sensation Collaboration Age (years)**

Presence = - 1 Absence = +1

+1 (<65) +2 (65-75)

dependency determined by the consistency in the differences detected.

the cervical trachea before, during or after swallowing is considered.

1 2 3

2 3 4

that does not cross the pharynx while swallowing.

**Pooling Endoscopic landmarks**

Valleculae Marginal zone Pyriform sinus Vestibule/vocal cords Lower vocal cords

Coating Minimum Maximum

< 2 2 ><5 > 5

**Table 6.** P-score and P-SCA score

Score P 4-11 P-SCA 3-16

Site

82 Seminars in Dysphagia

Management

45 = minimum score, corresponding to no dysphagia

6\_7 = low score, corresponding to a mild dysphagia

8\_9 = middle score, corresponding to a moderate dysphagia

10\_11 = high score, corresponding to a severe dysphagia

*P-SCA score:*

3\_4 = minimum score, corresponding to no dysphagia

5\_8 = low score, corresponding to a mild dysphagia

9\_12 = middle score, corresponding to a moderate dysphagia

13\_16 = high score, corresponding to a severe dysphagia.
