py.

_Diagnosis_.--Roentgenray study with barium mixtures, is the first
step in the diagnosis (Fig. 101). This is to be followed by diagnostic
esophagoscopy. Malignant, spasmodic, cicatricial, and compression
stenosis are to be excluded by esophagoscopic appearances. Aneurysm is
to be eliminated by the usual means. The Boyce sign is almost
invariably present, and is diagnostic. It is elicited by telling the
patient to swallow, which action imprisons air in the sac. The
imprisoned air is forced out by finger-pressure on the neck, over the
sac. The exit of the air bubble produces a gurgling sound audible at
the open mouth of the patient.

_Esophagoscopic Appearances in Pulsion Diverticulum_.--The
esophagoscope will without difficulty enter the mouth of the sac which
is really the whole bottom of the pharynx, and will be arrested by the
blind end of the pouch, the depth of which may be from 4 to 10 cm. In
some cases the bottom of the pouch is in the mediastinum. The walls
are often pasty, and may be eroded, or ulcerated, and they may show
vessels or cicatrices. On withdrawing the tube and searching the
anterior wall, the subdiverticular slit-like opening of the esophagus
will be found, though perhaps not always easily. The esophageal
speculum will be found particularly useful in exposing the
subdiverticular orifice, and through this a small esophagoscope may be
passed into the esophagus, thus completing the diagnosis. Care must be
exercised not to perforate the bottom of the diverticular pouch by
pressure with the esophagoscope or esophageal speculum. The walls of
the sac are surprisingly thin.

[FIG. 101.--Pulsion diverticulum filled with bismuth mixture in a man
of fifty years.]

_Treatment of Pulsion Diverticulum_.--If the pouch is small, the
subdiverticular esophageal orifice may be dilated with esophagoscopic
bougies, thus overcoming the etiologic factor of spastic or organic
stenosis. The redundancy remains, however, though the symptoms may be
relieved. Cutting the common wall between the esophagus and the sac by
means of scissors passed through the endoscopic tube, has been
successfully done by Mosher.

Various methods of external operation have been devised, among which
are: (1) Freeing the sac through an external cervical incision and
suturing its fundus upward against the pharynx, which has proved
successful in some cases. (2) Inversion of the sac into the pharynx
and suture of the mouth of the pouch. In a