Component 14: Pharyngoesophageal Segment Opening
Pharyngoesophageal segment (PES) opening results in the combined result of relaxation of the
cricopharyngeal muscle and traction placed by contraction of the suprahyoid muscle that pull the larynx,
particularly the cricoid cartilage, away from the posterior pharyngeal wall. PES opening is judged during the
point of maximal distention of the PES and throughout opening to closure. In the case of the sequential
swallowing task, each swallow is considered in formulating the OI score.
SCORING CONSIDERATIONS
Three dimensions are considered when scoring PES opening:
1) Distension (how wide the segment opens)
2) Duration (how long the segment stays open)
3) Obstruction to flow (whether or not bolus flow is obstructed)
One must consider both the degree of distension and duration of PES opening and the outcome, which is
obstruction to bolus flow, when tabulating a score for PES opening. Even if the patient has only one or two
impaired dimensions, they should receive a score that characterizes the most severely impaired dimension.
DISTENSION
Distension is defined by how wide the PES opens. The following annotated graphic demonstrates the
varying levels of PES distension and associated MBSImP™© nomenclature.
complete distension
partial distension
minimal distension
no distension
When there is complete distension, the pharynx will appear to have relatively straight edges through the
PES with no appreciable narrowing to the proximal esophagus. Partial distension is evidenced by a
narrowing of the PES at the esophageal inlet. Minimal distension appears as significant narrowing of the
PES and no distension is evidenced by complete absence of PES opening. Generally, obstruction of bolus
flow increases as degree of distension decreases.
DURATION
Duration is defined by how long the PES remains open. The following image sequences demonstrate the
varying levels of PES duration and associated MBSImP™© nomenclature.
Complete duration of PES opening allows for the entire bolus to pass through the esophageal inlet without
obstruction of bolus flow:
Partial duration maintains PES opening long enough for most of the bolus to pass. Early collapse of the PES
is often associated with incomplete anterior hyoid movement (Anterior Hyoid Excursion, Component 9):
Minimal duration of PES opening results in rapid collapse of the PES causing marked obstruction of flow:
Absence of PES opening prevents bolus clearance. If the PES does not distend you cannot rate duration:
(0) complete duration with relatively straight edges through the PES and no appreciable narrowing from
the pharynx to proximal esophagus. When assigning a score of (0), there should be no obstruction to
flow.
(1) A score of (1) is represented by partial distension evidenced by a narrowing of the PES at the
esophageal inlet. A score of (1) should result in partial obstruction to flow.
(2) A score of (2) is minimal distension with significant narrowing of the PES resulting in resistance to bolus
OBSTRUCTION
Obstruction of bolus flow generally results in some degree of pharyngeal residue and is a byproduct of
reduced distension of the PES, reduced duration of PES opening, or a combination of both. One or any
combination may be impaired. For example, the PES may fully distend but close early (incomplete duration)
because of suprahyoid muscle weakness to sustain hyolaryngeal displacement, a primary traction force that
contributes to PES opening.
SCORE DEFINITIONS
Given the need to simultaneously observe distension, duration and obstruction to flow when scoring,
Component 14 does not lend well to still images and the user is strongly encouraged to view the videos
within the Learning Zone.
(0) Complete distension/complete duration; no obstruction of bolus flow:
The PES fully distends and remains distended long enough for the entire bolus to pass through the
esophageal inlet.
(1) Partial distension/partial duration; partial obstruction of flow:
A score of (1) can be represented in several ways:
a) Narrowing of the PES at the esophageal inlet while maintaining opening long enough for most of
the bolus to pass.
b) Adequate distension of the PES but with early collapse allowing most of the bolus to pass.
c) Both narrowing and early collapse of the PES resulting in partial obstruction.
(2) Minimal distension/minimal duration; marked obstruction of flow:
A score of (2) can appear as follows:
a) Significant narrowing of the PES resulting in resistance to bolus passage.
b) Rapid collapse of the PES allowing only a minimal portion of the bolus to pass.
c) Both significant narrowing and rapid collapse of the PES resulting in marked obstruction.
(3) No distension with total obstruction of flow:
The PES does not open and there is no bolus clearance. This generally results in the need for the patient to
expectorate the bolus. Escape into the laryngeal vestibule or nasal cavity is common.