A Novel Treatment Option for Esophageal Stricture
By: Peter S Chapman BVetMed, DECVIM-CA, DACVIM, MRCVS
Board-Certified Internal Medicine Specialist
Veterinary Specialty & Emergency Center
Esophageal strictures are an uncommon but important cause of esophageal disease in dogs and cats. They most commonly occur secondary to esophagitis, which leads to the development of scar tissue within the submucosa. The scarring prevents passage of normal food boluses. In general, esophageal strictures only secondary to severe esophagitis caused by severe chemical irritation from gastric acid or medications – doxycycline and clindamycin are the most commonly implicated medications. Esophagitis of sufficient severity to cause a stricture is rarely seen after a simple episode of vomiting or with intermittent gastroesophageal reflux. Sufficiently prolonged exposure of the esophageal mucosa generally occurs only with reflux under general anesthesia – especially prolonged anesthetic events.
The primary clinical sign associated with an esophageal stricture is regurgitation. Typically patients want to eat but are unable to keep any solid food down. Unlike in patients with megaesophagus, who may eat a normal meal and then regurgitate after minutes to hours, patients with esophageal strictures will start to gag and show discomfort within second of eating before forcefully regurgitating the ingesta. Water is generally better tolerated and sometimes very soft/liquid foods may transit the esophagus without problems. Unlike in megaesophagus, where the signs may be variable and ameliorated or ameliorated by changes in feeding routine, patients with a stricture will generally regurgitate every meal.
Radiographs are critical in patients with regurgitation to rule out other differential diagnoses such as megaesophagus and esophageal foreign bodies. However, plain radiographs are usually normal in patients with esophageal strictures since any esophageal dilation cranial to the stricture is relieved after ingests is regurgitated. Feeding barium mixed with food may reveal a focal esophageal dilation but the number and extent of any strictures caudal to the first obstruction is difficult to assess. When a suspicion exists for esophageal stricture and plain radiographs are normal, the diagnostic test of choice is endoscopy. Endoscopy allows full visualization of the extent and number of any strictures, as well as an assessment of the degree of concurrent esophagitis.
Successful treatment of esophageal strictures requires dilation of the stricture and prevention of recurrence. Endoscopic balloon dilation is the most widely accepted treatment. Under endoscopic visualization, a balloon is passed into the stricture and inflated to a pre-determined pressure to exert a radial force and break down the scar tissue. Progressively larger balloons are used to open up the stricture to a more normal diameter. The end point of the ballooning is assessed subjectively based upon the diameter of the esophageal lumen or the procedure is reached when there is evidence of significant tearing and hemorrhage of the esophageal mucosa or when the esophageal luminal diameter is assessed to be adequate. This procedure has an excellent short term outcome with most patients able to tolerate oral food immediately after the procedure. However, the rate of recurrence is high and multiple procedures may needed to be performed to achieve a good long term outcome – 50% of patients will need 2 or more treatments and sometimes give or more may be required to achieve a good long term. Each requires general anesthesia, usually at intervals of 1-2 weeks based on the recurrence of clinical signs
Attempts to limit the risk of recurrence are often made by administering, acid blockers, sucralfate and systemic glucocorticoids – the latter to limit inflammation and slow scar tissue formation. Placement of a PEG-tube may also be helpful if there are severe changes to the esophageal mucosa that are expected to negatively affect appetite.
Figure One: esophageal stricture
Figure Two: balloon dilation catheter used to dilate stricture
Figure Three: BE-tube can be seen in the esophagus, dorsal to the ET-tube. The balloon can be seen inflated between the two metallic markers.
Given the high rate of recurrence after balloon dilation, alternative strategies have been attempted in patients with intractable strictures. Stent placement would seem to be a rational approach for dogs with recurrent strictures. However, stent placement was associated with a a high rate of complications and low success rate in a published case series. A newer technique, developed by Drs Chick Weisse and Allyson Berent at the Animal Medical Center in New York, shows more promise. This technique uses an indwelling balloon (a “balloon esophagostomy” or “BE” tube) that was developed at the AMC. The BE-tube comprises a long silicone tube with a balloon wrapped around its outer wall at the distal end. It is placed in a similar manner to an esophagostomy tube and positioned such that the balloon lies at the level of the stricture. The balloon can be transiently inflated by the patient’s caregivers on a twice daily at home basis. This breaks down any scar tissue that is reforming and facilitates the healing of the esophagus with a more normal diameter. The inner lumen of the tube can be used for providing enteral nutrition. In most patients this is not necessary since they maintain a good appetite and it is possible for swallowed food to pass alongside the tube, as with a conventional esophagostomy tube. At the ACVIM forum in 2015, Drs Weisse and Berent presented preliminary results of BE-tube placement in 6 dogs – three dogs had a complete resolution of their signs, one was markedly improved, one mildly improved and one was euthanized due to other disease.
At VSEC, we have been one of the few centers outside the AMC to employ this technique for the treatment of esophageal stricture. Our first BE-tube was placed in an eight year old Border collie mix, who had developed severe esophagitis after routine uncomplicated anesthesia for dental procedures. The initial signs of gagging and reverse sneezing after eating improved with initial treatment of the esophagitis but after six weeks the dog started to regurgitate immediately after eating. Esophagoscopy confirmed the presence of an esophageal stricture that was managed by three balloon dilations at two week intervals. After the signs recurred a fourth time, a BE-tube was placed. The tube as well-tolerated by the patient and his family and was able to be kept in place for thirty-nine days with twice daily inflations and no need for supplemental feeding. After tube removal, the patient continued to do well and at six months post-removal there has been no need for further treatment.
BE-tube placement holds significant promise for treatment of recurrent esophageal strictures. Moreover, given the high rate of recurrence with conventional treatment, it may be even prove to be a rational first line treatment.
If you have a patient that you would like to be evaluated or treated for esophageal disease, or if have any other questions regarding your internal medicine patients then please call one of the VSEC internal medicine team at 215-750-7884.
Dr. Peter Chapman is a Board-Certified Internal Medicine Specialist at the Veterinary Specialty & Emergency Center. The Veterinary Specialty & Emergency Center operates state-of-the-art emergency and specialty veterinary hospitals that are open 24/7/365 in both Levittown PA and Philadelphia PA. For more information about our world-class emergency and specialty care, please visit VSEC on the web at www.VSECVET.com.