The esophagus is the tube that propels food from the mouth to the stomach. This path is narrowed at the entrance to the chest, then where it goes over the heart and finally where it goes through the diaphragm opening into the stomach. Strictures tend to form at these areas. Strictures occur when the esophagus is injured. Injury is most common caused by swallowed foreign bodies, but another common cause is ulceration caused by gastric fluids secondary to anesthesia.
Anesthesia agents relax the sphincter at the junction of the stomach allowing acid to reflux in the esophagus pooling in the areas of narrowing and causing irritation, and ulceration. Injury to the esophagus causes excessive scar tissue formation resulting in strictures and eventual obstruction.
The pet with esophageal disease regurgitates food and cannot tolerate dry food.
Regurgitation is different from vomiting in that vomiting is a disease of the stomach with the typical winding up and retching culmination in expulsion of the stomach contents.
Regurgitation is a silent process with almost passive emptying of the esophageal contents usually covered in saliva.
Diagnosis is made with contrast radiographs that will demonstrate the narrowed isthmus of the esophageal stricture. Treatment is successful in about 70% to 85% of the time with balloon dilation but only about 15% of the pets can tolerate dry food without regurgitation. Some pets cannot be cured despite short term remission after dilation.
The scar tissue in these pets reforms within a week or so. Esophageal stents are effective in humans but have not been as effective in dogs with over 70% failure rate in some studies.
To perform balloon dilation a special procedures room is necessary with C-Arm radiology for real time radiograph video viewing as well as video endoscopy. The Safari Veterinary Care Center special procedures room has this equipment and more including full anesthesia and monitoring as this procedure requires general anesthesia.
Balloon catheters are designed to go through the narrow isthmus of the stricture obstruction. They are then inflated with dye that allows us to see them on the fluoroscopic radiographs. The balloon catheter is about 3 inches long and will gradually dilate as it inflates. The stricture is shown as the narrow spot in the middle of the balloon.
After the stricture is dilated, the pet will be able to eat soft food. Scar tissue however starts to form immediately causing the site to reform the stricture within 7 days. This scar tissue is inhibited by injecting cortisone into the esophagus at the stricture through a special needle that goes through the endoscope. A cancer therapy medication that inhibits tissue growth is also soaked onto a sponge and applied to the area for 5 minutes to reduce scar tissue. This process is repeated every 5 to 7 days for 5 treatments to keep the esophagus from reforming the scar.
These cases are challenging for the client and the pet and therapy requires specialized equipment and specialized knowledge. Safarivet is one of the few that have these abilities.
Capuchin Monkey Esophageal Stricture and Balloon Dilation
Adopted at one year of age, was noticed to be thin and needed to gain weight at that time had not been weaned from formula. Was diagnosed with pneumonia and noticed by the owner to have hiccups and spit ups after eating. Treated for pneumonia successfully but continued to vomit and was not gaining weight. Radiographs with barium revealed obstruction in the esophagus. Endoscopy confirmed stricture. Balloon dilation elected after medical therapy failed. Balloon dilation was successful in removing all clinical signs. This video shows the second dilation for this little monkey which was done one week apart for four procedures. This is the usual case for esophageal strictures – four treatments is usually curative. After the dilation procedures were completed she became normal, gained weight, began eating solid or semi-solid food and resumed normal activity. 5 months later however she started showing signs again and this time the esophagus was completely obstructed.. During the fifth dilation procedure the esophagus ruptured and she passed.