Esophageal Strictures in Small Animals
Esophageal stricture is a pathologic narrowing of the lumen that may develop after anesthesia, trauma (eg, foreign body), ingestion of caustic substances, exposure to certain drugs (such as doxycycline or clindamycin), esophagitis, gastroesophageal reflux, or tumor invasion. Most strictures develop in the thoracic portion of the esophagus. Esophageal tumors are rare, but esophageal sarcomas may be associated with Spirocerca lupi infection (see Spirocerca lupi in Small Animals), requiring consideration in areas where this parasite is prevalent. Esophageal compression by vascular ring anomalies or extramural tumors may mimic the signs of strictures.
Clinical signs are similar to those associated with foreign bodies and include regurgitation, ptyalism, dysphagia, and pain. An esophagram under fluoroscopy is the preferred tool for diagnosis, because it allows visualization of the number, length, location, and severity of strictures. Esophagoscopy can also be diagnostic but does not allow visualization beyond the stricture unless esophageal balloon dilation is also performed.
Treatment with balloon catheter dilation has been the most successful. Bougienage is another, less available, technique. It theoretically causes more shear stress on the esophagus but has not been shown to have a significantly different complication rate than balloon dilation. Some cases can require multiple dilation procedures. Esophageal stents have been used in strictures that have been refractory to dilation procedures. However, this method has been limited by a high rate of complications, including stent migration, stent shortening, stent breakage, recurrence of stricture, infection, megaesophagus, overgrowth of tissue into the stent, ptyalism, apparent nausea, gagging, vomiting, regurgitation, and tracheal-esophageal fistula. Surgical resection of a single stricture is another option; however, it is less successful. These treatments are likely to induce some degree of esophagitis, which must be treated to decrease the chance of stricture reformation. The use of corticosteroids, either systemically or intralesionally, to help prevent stricture reformation is controversial. No data exist regarding the success of this adjunct therapy for esophageal strictures in dogs and cats, but intralesional use has been helpful in reducing recurrence in people.