An outpouching or, in effect, a hernia of the swallowing passage just above a non-relaxing cricopharyngeus muscle. In essence, the forces of swallowing are delivered against a somewhat unyielding muscle, and this causes the wall of the swallowing passage just above the cricopharyngeus muscle (i.e., the upper esophageal sphincter) to balloon outward. Hence, unknown to many, the Zenker’s diverticulum is only the reflection of the main problem, which is cricopharyngeal dysfunction. Myotomy of the cricopharyngeus muscle tends to resolve symptoms, even though the Zenker’s diverticulum is left in place and not removed.
Photos:
Cricopharyngeal dysfunction, with incipient Zenker’s (1 of 1)
This patient with cricopharyngeal dysfunction is just beginning to form a Zenker’s pouch. Note that the cricopharyngeus muscle (light grey “thumb” at asterisk) is beginning to turn upwards and become more slender. The volume of barium below the dotted line is inside the incipient Zenker’s pouch. Over months or years, this pouch would stretch and develop into a true Zenker’s pouch.
Zenker's diverticulum (1 of 3)
This view is a moment after a completed swallow of blue-stained applesauce.
Zenker's diverticulum (2 of 3)
Same view, a second later, as blue-stained applesauce emerges from the Zenker's diverticulum upward (toward the camera) into the postcricoid area.
Reflux into hypopharynx (1 of 3)
The patient has swallowing problems typical of cricopharyngeal dysfunction. This swallow study reinforces that impression as well as the likely presence of a Zenker's diverticulum. In this photo, blue-stained water has just been swallowed, and the vocal cords are beginning to open. At this point, the hypopharynx contains no residue.
Reflux into hypopharynx (2 of 3)
One second later, the blue-stained water begins to emerge from just above the cricopharyngeus muscle into the "swallowing crescent".
Orientation (1 of 4)
The 'X' is for orientation with next photo; 'A' is for right arytenoid eminence (left of photo). The arrow points to the area of focus of the next photo.
View into post-arytenoid and post-cricoid area (2 of 4)
View into post-arytenoid and post-cricoid area. The 'X' orients to the same place in photo 1. The esophageal entrance is just beginning to appear at the arrow.
Esophageal and Zenker sac openings (3 of 4)
Descending further, we see two potential openings. 'E' designates actual esophageal opening and 'Z' the opening to the Zenker's sac. Between the dotted lines is the cricopharyngeus muscle bar.
Zenker’s diverticulum (1 of 4)
This middle-aged woman has had a known Zenker’s diverticulum for several years. She has now reached a point of frustration that has motivated her to proceed with cricopharyngeus myotomy. The series that follows explains some of the reason for her frustration. In this view, the patient has just completed a swallow of her saliva.
Saliva from Zenker's sac (2 of 4)
A few seconds later, saliva begins to return upwards into the post-arytenoid area (at arrow) from the Zenker’s sac.
Immediately after swallow (1 of 4)
During VESS, after administration of several boluses of blue-stained applesauce. Trace applesauce on pharyngeal walls, immediately after a completed swallow. The postcricoid area is “clean” in this view, at *.
One second later (2 of 4)
Approximately a half second later, applesauce appears at the *, having been ejected upwards from a presumed Zenker’s diverticulum.
Un-relaxed cricopharyngeus muscle (3 of 4)
During water administration, a glimpse of the un-relaxed cricopharyngeus muscle is seen (concentric dotted lines). Esophageal entrance at ‘E’ and Zenker’s pouch, still containing some previously-administered blue applesauce, at ‘Z'.
(1 of 3)
During Videoendoscopic swallow study (VESS), this patient has just swallowed blue applesauce. It has disappeared downwards (arrows) into the upper esophagus but part of it is retained in a Zenker's diverticulum (out of view).
(2 of 3)
Exactly one second later blue applesauce appears in the swallowing crescent as the sac empties a part of its contents upwards.