Page 487 - Small Animal Internal Medicine, 6th Edition

CHAPTER 29 Disorders of the Oral Cavity, Pharynx, and Esophagus 459

there is extremely severe damage. Perforations from blunt
foreign objects that caused esophageal wall necrosis usually
VetBooks.ir require thoracotomy to clean out septic debris and close the
esophageal defect. However, acute perforations from sharp
objects (e.g., fish hooks) not associated with esophageal wall
necrosis may often be treated by placing a gastrostomy tube,
giving nothing per os, and allowing the perforation to spon-
taneously seal.
Prognosis
The prognosis for animals with esophageal foreign bodies
without perforation is usually good. Perforation warrants a
more guarded prognosis, depending on the size of the per-
foration and the presence/severity of thoracic contamina- A
tion. Subsequent cicatrix and obstruction is possible if
substantial mucosal damage occurs. Bone foreign bodies,
small body size (i.e., < 10 kg), and chronicity appear to be
risk factors for complications.

ESOPHAGEAL CICATRIX (BENIGN
STRICTURE)

Etiology
Severe, deep inflammation of the esophagus from any cause
(especially foreign bodies or severe gastroesophageal reflux)
is usually required for cicatrix to occur.
Clinical Features
Esophageal cicatrix occurs in both dogs and cats. The main B
sign is regurgitation (especially of solids). Some animals are
hyporexic due to pain experienced when food becomes FIG 29.7
lodged at the stricture by forceful esophageal peristalsis. Rare (A) Lateral contrast esophagram using liquid barium. There
patients have severe respiratory stridor due to cicatrix in the is some narrowing of the barium column but no obvious
lesion. (B) Liquid barium has been mixed with canned food;
nasopharynx or at the choanae (see Chapter 16). a stricture in the midcervical esophagus is now very
obvious. Note that the stricture is not at the thoracic inlet,
Diagnosis which is where one might have suspected a stricture to be
Partial obstructions due to cicatrix may be difficult to diag- most likely on the first image.
nose. Positive-contrast esophagrams in which barium is
mixed with food are often necessary (Fig. 29.7). Esophagos-
copy is definitive (Video 29.5), but a partial stricture may not Bougienage can likewise be done with endoscopic or fluoro-
be obvious in large dogs unless the endoscopist is experi- scopic guidance. It can more easily cause a rupture but is
enced and the esophagus is carefully inspected. Likewise, it relatively safe and equally effective if done by a trained indi-
is easy to miss strictures at the lower esophageal sphincter. vidual. After the stricture has been dilated, significant trau-
Strictures in the nasopharynx or at the choanae require ret- matic esophagitis may be present. If it is present, it should
roflexed endoscopic examination of these areas. be treated aggressively with proton pump inhibitors and
gastric prokinetics. Some animals are cured after one dilata-
Treatment tion, whereas others require multiple procedures.
Surgical resection/anastomosis is not recommended. Treat- In difficult patients in which the stricture recurs repeat-
ment consists of correcting the suspected cause (e.g., esopha- edly after dilatation, more advanced techniques can be tried.
gitis) and/or widening the stricture by ballooning or Intralesional steroid injections, three-quadrant cuts into the
bougienage. It is important that the clinician have substantial stricture using endoscopic electrosurgery or laser, topical
training dilating strictures and the correct equipment. Bal- application of mitomycin C, placing a stent, and placing a
looning has less chance of perforation than bougienage and balloon-esophagostomy tube have all been tried. Each has
may be accomplished with endoscopic or fluoroscopic guid- benefited some cases, but none is guaranteed to work; the
ance. Angioplasty catheters or esophageal dilation balloons author has seen each technique fail. Almost all strictures
are more useful than Foley catheters because the latter typi- at the choanae require stenting. Nasopharyngeal stric-
cally slide to one side of the obstruction during inflation. tures are very difficult to treat and should be immediately