Esophagitis secondary to hairball
Inflammation and subsequent scar tissue formation within the esophagus can lead to an esophageal stricture. Esophageal stricture is an important cause of morbidity and mortality in dogs and cats. Most commonly, benign esophageal stricture is secondary to gastroesophageal reflux of stomach acid. Other possible causes include foreign bodies, or any cause of mechanical or chemical injury to the esophagus.
Common symptoms in patients with esophageal strictures includes regurgitation, choking, and occasionally respiratory distress due to secondary aspiration pneumonia. A fluoroscopy assisted esophagram may be recommended to confirm the diagnosis.
Fluoroscopy assisted esophagram
The goal of treating benign esophageal strictures is to reduce the frequency of regurgitation to the point that oral feeding can be used to maintain nutrition and hydration. The current mainstays of mechanical dilation therapy include endoscopic-guided balloon dilation and/or bougienage. A successful outcome often requires two or greater dilation therapies; these treatments are performed under general anesthesia, which can encourage further esophageal reflux, and can be costly. Overall, balloon dilation has been associated with a good outcome in 74-88% of cases. Good outcome has been defined as the ability of patients to eat soft food or gruel. Additionally, 2 of more dilation procedures are required to achieve a successful outcome. Few (likely less than 20%) of patients regain the ability to eat normal food. Additionally, there are a few dogs that have a tremendous ability to form scar tissue that are ballooned multiple times unsuccessfully. Mortality is previous studies was approximately 20% (22/113) and number of balloon dilations varied from 1 to 10. Esophageal stenting has been attempted as a possible one-stage solution for strictures. Unfortunately, the stents are often not well tolerated by the patients, with subsequent high rates of gagging and discomfort.
Endoscopy and esophageal balloon dilation
The lack of success has prompted the evaluation for other treatment options. Ideal treatment seems to be associated with the ability of providing consistent dilation of the stricture to prevent reformation, but also permit easy removal of the device (if not well tolerated). The B-tube (balloon esophagostomy tube) is a one-stage esophageal balloon dilation feeding tube, which can lead to effective, single procedure alternative to repeated balloon dilation procedures for the treatment of benign esophageal strictures. A study looking at 9 dogs and 3 cats showed that approximately 70% of patients were able to eat a normal diet by the end of treatment. The main concern with B-tube placement and continuous ballooning is the potential of esophageal rupture, which is a risk with standard esophageal stricture balloon dilation as well. Dislodgement or malfunction of the B-tube have been reported but are considered uncommon. Gagging and temporary discomfort is typically noted during balloon dilation procedures. Improvement of the modified dysphagia score improved in 92% of cases and mortality was 8.3% vs. 12-30% previously reported for standard balloon dilation.
Preliminary results indicate minor complications including insertion site irritation/infection, inflation discomfort, and early tube failure (repaired). All these complications were relatively minor, self-limiting, and easily resolved. Performing the inflations does require dedicated owners. The first patients treated have been reported (Tan et al., JVIM) and have demonstrated that the B- Tube has the potential for improved (and less expensive) outcomes in the treatment of esophageal strictures with ~70% of patients eating a normal diet following B-tube removal.