descending to its resting position."/>
Figure 6.12 Pseudo‐Zenker’s diverticulum. (A) Lateral view of the pharynx during drinking shows an open pharyngoesophageal segment (arrow) identified by redundant postcricoid mucosa. (B) Lateral view of the pharynx just after the bolus passes shows how the pharynx is descending to its “resting” position. Barium is trapped (thin arrow) between the early closing pharyngoesophageal segment (thick arrow) and the posterior pharyngeal contraction wave that has just passed. The transiently trapped barium entered the esophagus moments later. Note the difference in height of the pharyngoesophageal segment and the bottom of the vocal cords (open arrows) during and after swallowing.
Barium trapped above a prematurely or incompletely opened cricopharyngeus may resemble a small Zenker’s diverticulum and has been termed a pseudo‐Zenker’s diverticulum [24] (Figure 6.12). In such patients, no diverticulum is seen during swallowing. The sac‐like structure appears only when the cricopharyngeus closes early or when barium is trapped between the pharyngeal contraction wave and the incompletely opened cricopharyngeus. After a few moments, this barium enters the cervical esophagus, and the sac disappears. It is not known whether a pseudo‐Zenker’s diverticulum can progress to a true Zenker’s diverticulum. Early closure and incomplete opening of the cricopharyngeus have also been associated with GERD [34] (Figures 6.13 and 6.14).
Killian–Jamieson diverticula and pouches
The Killian–Jamieson space is a triangular area of weakness in the upper anterolateral cervical esophagus, not to be confused with Killian’s dehiscence. The Killian–Jamieson space is bounded superiorly by the inferior border of the cricopharyngeus, anteriorly by the cricoid cartilage, and inferomedially by the suspensory ligament of the esophagus [35]. Transient protrusions through the Killian–Jamieson space are called lateral proximal cervical esophageal pouches, whereas persistent protrusions are called lateral proximal cervical esophageal diverticula. These structures are also known as Killian–Jamieson pouches and diverticula, respectively [36].
Killian–Jamieson diverticula, which are about one‐third as common as Zenker’s diverticula, have a characteristic radiographic appearance [36]. They are either unilateral, usually on the left, or bilateral [6]. The diverticula appear on barium studies as persistent 3–20 mm outpouchings with distinct necks (Figure 6.15). The diverticula extend lateral to the cervical esophagus on frontal views and overlap the cervical esophagus on lateral views. In contrast, a Zenker’s diverticulum is in the midline on frontal views and posterior to the cervical esophagus on lateral views (Figure 6.16). When barium is regurgitated from Killian–Jamieson diverticula, it enters the cervical esophagus because the diverticula are below the cricopharyngeal muscle. Thus, there is a lower risk of aspiration from Killian–Jamieson diverticula than from Zenker’s diverticula. Killian–Jamieson pouches appear as small, transient outpouchings just below the closing cricopharyngeus muscle and are usually detected near the end of swallowing or after the bolus has passed through the cervical esophagus.
Figure 6.13 Incomplete opening of the cricopharyngeus. (A) Lateral view of the pharynx obtained just as the bolus (e) is entering the hypopharynx. (B) Lateral view of the pharynx at the end of bolus passage. The cricopharyngeus (long white arrow) is closing before the bolus has cleared the hypopharynx. The posterior pharyngeal contraction wave is identified (thick white arrow). A jet of barium (black arrow) spurts through the anterior wall of the cervical esophagus.
Lateral pharyngeal pouches and diverticula
Lateral pharyngeal pouches are transient outpouchings of the proximal anterolateral hypopharyngeal wall, whereas lateral pharyngeal diverticula are persistent sacs through the same area of weakness in the pharyngeal wall [37]. Lateral pharyngeal pouches protrude through an area bounded superiorly by the hyoid bone, anteriorly by the thyrohyoid muscle, inferiorly by the ala of the thyroid cartilage, and posteriorly by the superior cornu of the thyroid cartilage [37] (Figure 6.17A).
Lateral pharyngeal pouches appear on barium studies as smooth‐surfaced hemispheric outpouchings of the upper anterolateral hypopharyngeal wall just below the level of the hyoid bone (Figure 6.17B,C). Barium enters the pouches and then spills into the ipsilateral piriform sinus, either late in the swallow or just after swallowing. Overflow aspiration is uncommon. In contrast, barium is retained in lateral pharyngeal diverticula long after the swallow has been completed (Figure 6.18). Lateral pharyngeal pouches are usually bilateral, whereas lateral pharyngeal diverticula are usually unilateral (Figure 6.18).
Lateral pharyngeal pouches are common, and their incidence increases with age. Lateral pharyngeal diverticula are much less common, usually occurring in patients with elevated intrapharyngeal pressures. Most of these patients are asymptomatic, but about 5% with lateral pharyngeal pouches complain of a feeling of incomplete swallowing [38, 39]. Patients with lateral pharyngeal diverticula may also complain of dysphagia, choking, regurgitation of undigested food, or a painless neck mass.
Branchial pouch sinuses and branchial cleft fistulae
In the four‐week embryo, paired grooves of ectodermal origin – the branchial clefts – appear on the sides of the neck. Four outpouchings of endodermal origin – the branchial pouches – grow to meet the branchial clefts [40]. The second branchial cleft forms the middle ear, eustachian tube, and floor of the tonsillar fossa. The third and fourth branchial pouches form the piriform sinuses. Persistence of branchial clefts or pouches may lead to the development of sinus tracks (that end blindly beneath the skin), fistulae (that extend to the skin), or cysts. Branchial pouch sinus tracks arise from the tonsillar fossa (second pouch) (Figure 6.19), the upper anterolateral piriform fossa (third pouch), or the lower anterolateral piriform sinus (fourth pouch).
Figure 6.14 Extrinsic impressions during passage of bolus through the pharyngoesophageal segment. A smooth‐surface hemispheric impression represents incomplete opening of the cricopharyngeus (white arrow). Osteophytes impress the proximal cervical esophagus (arrowhead). Also note redundant post‐cricoid mucosa (open arrow) opposite the cricopharyngeal bar.
Source: Reproduced from Rubesin SE. Oral and pharyngeal dysphagia. Gastroenterol Clin North Am1995; 24:331–352, with permission.
Inflammatory conditions
Although barium studies are of limited value in immunocompetent patients with an acute sore throat, they may be of value for demonstrating acute inflammatory lesions in the pharynx in immunocompromised patients with suspected Candida (Figure