STANDARDS of CARE. Esophageal foreign bodies are a relatively common EMERGENCY AND CRITICAL CARE MEDICINE ESOPHAGEAL FOREIGN BODIES AND STRICTURES

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1 Peer Reviewed DECEMBER 2005 VOL 7.11 STANDARDS of CARE EMERGENCY AND CRITICAL CARE MEDICINE FROM THE PUBLISHER OF COMPENDIUM ESOPHAGEAL FOREIGN BODIES AND STRICTURES Debra L. Zoran, DVM, PhD, DACVIM (Small Animal Internal Medicine) Associate Professor Department of Small Animal Clinical Sciences College of Veterinary Medicine and Biomedical Sciences, Texas A&M University Esophageal foreign bodies are a relatively common cause of esophageal injury in dogs and are a less common, but still important, problem in cats. Because of their less-discriminating eating habits, dogs may consume a variety of food and nonfood materials that can lodge in the esophagus, causing pain, regurgitation, and potentially severe esophageal injury. Esophageal foreign bodies in cats tend to be string or linear foreign bodies and are frequently wrapped around the base of the tongue, which serves as an anchor to prevent passage. Because cats seldom inhale or rapidly consume bones whole or grab food, the typical esophageal foreign bodies observed in dogs are not a clinical problem in cats. Esophageal foreign bodies that are not removed expeditiously may cause significant damage to the esophageal mucosa or submucosa. The longer a foreign body is retained, the greater the risk for perforation or formation of an esophageal stricture after the object is removed. Thus, the presence of any esophageal foreign object should be considered a medical, endoscopic, and/or surgical emergency. An esophageal stricture is a circular or semicircular band of scar tissue that forms after significant injury to esophageal tissue (i.e., injury extending deeper than the mucosa). The resultant scar tissue impedes the movement of food through the esophagus by limiting the size of items that can pass through the stricture site and may even affect esophageal motility if the esophageal tissue is diseased or dilated long enough. In some cases, the opening in the esophageal lumen is the size of a pin. Regardless of the size of the stricture, the end result is an impaired ability to move a food bolus from the mouth to the stomach, and the affected animal regurgitates some, if not all, of the food consumed. Numerous esophageal injuries can lead to the development of a stricture. The primary impetus for stricture formation is the loss of the protective esophageal mucosa, either acutely from injury or chronically from persistent exposure to gastric acid. Once the inflammation reaches the deeper submucosal and muscular layers, the response to injury is predictable and, ultimately, detrimental. Inflammation within these deeper tissues triggers the formation of fibrous connective tissue, which, in the circular tube structure of the esophagus, will eventually form a scar; if the lesion is circumferential, a cicatrix forms around the lumen, and the stricture is formed. With continued production of scar tissue, the esophageal lumen is gradually and circumferentially reduced in size, preventing first the passage of food and eventually even liquids. In some animals that have been without significant nutrition for days, appropriate support may require surgical placement of a gastrostomy tube (a percutaneous endoscopic gastrostomy [PEG] tube cannot be placed if an endoscope is unable to pass the stricture site). However, placement of a PEG tube should be possible in most cases after the balloon procedure. Rarely, placement of a central (jugular) catheter may be needed to allow intravenous nutritional support in animals that are not candidates for surgical tube placement. Animals with severe strictures or strictures at multiple sites will likely require several balloon procedures (over days or Also in this issue: 7 Systemic Lupus Erythematosus 1 Back Issue Archive Now Available! Visit for details.

2 weeks), in which case placement of a PEG or gastrostomy tube can be very beneficial. Further, a feeding tube placed in the stomach allows easier administration of medications in animals in which the oral route is not feasible. Because of the nature of the esophagus and its response to injury, surgical treatment of esophageal injury is used only as a last resort or in cases in which the stricture is caused by neoplasia or infection. The risk of postoperative stricture formation is high, especially in patients undergoing esophageal resection. Retrieval of esophageal foreign bodies via endoscopy is preferable. These approaches allow for the successful retrieval of most foreign bodies and provide good visualization of the mucosa for determination of prognosis. Exceptions include cats with string foreign bodies that extend into the stomach and duodenum and dogs with fishhooks that have migrated out of the esophagus into the neck or thoracic cavity, or when retrieval has been unsuccessful. The most effective approach to esophageal stricture management to date is dilation of the cicatrix using balloon catheters of gradually increasing size. The goal of this approach is not to achieve complete normalcy of the esophagus, which is not possible in most stricture patients. However, with ballooning and gradual stretching of the connective tissue band to the point where it heals with a larger opening, the goal is for the affected animal to be able to consume liquid gruel or canned foods and maintain normal weight and function. Complete resolution of regurgitation or the ability to consume dry or even some canned foods may not be possible. The key is to make owners aware of the limitations their pet will have; under these circumstances, success can be achieved in 80% of affected animals. DIAGNOSTIC CRITERIA Historical Information Gender/Age/Breed Predispositions: None. Owner Observations Acute onset of regurgitation is the most commonly reported clinical sign of esophageal disease. Owners may report coughing (especially if animals have aspirated), gagging or retching (especially if the foreign body or stricture is in the most cranial portion of the esophagus), and loss of appetite. Cats with esophageal strictures may be uninterested in eating, especially if the stricture is caused by esophagitis, or may have a good appetite but be unable to keep food down; either way, weight loss becomes obvious. If esophagitis is the cause of stricture formation, vomiting may be reported. Fever, drooling, and increased attempts to swallow are less frequently observed. Other Historical Considerations/Predispositions Esophageal foreign bodies are a more common occurrence in dogs, whereas esophageal strictures appear to develop more in cats. Dogs that are allowed to consume bones, greenies, rawhide, or other chew treats and those that chew on objects in general are more likely to have such KEY TO COSTS $ indicates relative costs of any diagnostic and treatment regimens listed. $ costs under $250 $$ costs between $250 and $500 $$$ costs between $500 and $1,000 $$$$ costs over $1,000 DECEMBER 2005VOL 7.11 STANDARDS of CARE EMERGENCY AND CRITICAL CARE MEDICINE Editorial Mission: To provide busy practitioners with concise, peer-reviewed recommendations on current treatment standards drawn from published veterinary medical literature. This publication acknowledges that standards may vary according to individual experience and practices or regional differences. The publisher is not responsible for author errors. Compendium s Standards of Care: Emergency and Critical Care Medicine is published 11 times yearly (January/February is a combined issue) by Veterinary Learning Systems, 780 Township Line Road, Yardley, PA The annual subscription rate is $83. For subscription information, call , fax , soc.vls@medimedia.com, or visit Copyright 2005, Veterinary Learning Systems. Editor-in-Chief Douglass K. Macintire, DVM, MS, DACVIM, DACVECC Editorial, Design, and Production Lilliane Anstee, Vice President, Editorial and Design Maureen McKinney, Editorial Director Cheryl Hobbs, Senior Editor Michelle Taylor, Senior Art Director Bethany L. Wakeley, Studio Manager Chris Reilly, Assistant Editor Kristin Sevick, Editorial Assistant Andrea Vardaro, Editorial Assistant Editorial Review Board Mark Bohling, DVM University of Tennessee Harry W. Boothe, DVM, DACVS Auburn University Derek Burney, DVM, PhD, DACVIM Houston, TX Joan R. Coates, DVM, MS, DACVIM University of Missouri Curtis Dewey, DVM, DACVIM, DACVS Plainview, NY Nishi Dhupa, DVM, DACVECC Cornell University D. Michael Tillson, DVM, MS, DACVS Auburn University 2 D E C E M B E R V O L U M E

3 items lodged in the esophagus. Other foreign bodies frequently found in dogs include rocks, wooden objects, and fishhooks. In cats, string, hair, and occasionally bones are common, although string per se rarely causes a problem in the esophagus. Chemical esophagitis (e.g., secondary to a capsule or tablet lodged in the esophagus or ingestion of chemicals such as petroleum products or cleaners while grooming the coat) is an important consideration in cats. A recent anesthetic episode is an important historical consideration if stricture is a differential. Physical Examination Findings Physical examination is often normal. Most animals with an esophageal foreign body present with acute onset of gagging, retching, coughing, and/or regurgitation. Drooling may be seen in patients that are in pain or have difficulty swallowing. Some dogs and cats with an esophageal foreign body may regurgitate food or water, retch, gag, or have increased attempts to swallow. Animals with esophageal strictures may have regurgitation, weight loss, increased attempts to swallow, drooling, and upper respiratory signs (sneezing or snorting) from regurgitated material entering the nasopharynx. The most common physical finding in dogs or cats with a long-standing stricture is weight loss. Coughing, fever, or increased bronchovesicular sounds may be heard in patients with aspiration pneumonia secondary to persistent regurgitation. Patient with a cervical esophageal perforation may be febrile or lethargic as a result of abscessation or the inflammatory process, but perforation of the intrathoracic esophagus results in pneumothorax and significant respiratory compromise. Laboratory Findings $ A minimum database (complete blood count, biochemistry profile, urinalysis) will likely be normal; any abnormalities are usually nonspecific. For example, clinical indicators of dehydration (elevated packed cell volume, increased total solids, and prerenal azotemia) are commonly found in pets that have not been able to eat or drink water for several days. If the pet has aspiration pneumonia or esophageal perforation as a complication, an inflammatory leukogram may be found. Other Diagnostic Findings Plain Thoracic/Abdominal Radiography $ Plain thoracic radiography is indicated for all regurgitating dogs or cats. Radiographs may be normal in some patients, but in most pets with foreign bodies, megaesophagus, the presence of retained food or air in the esophagus, or abnormalities in the thoracic cavity (e.g., mass impinging on the esophagus) will be diagnostic. Plain thoracic films are also necessary to determine if aspiration pneumonia is present in an animal that has been regurgitating. Plain abdominal radiography is indicated when esophagitis or stricture is a differential to determine if there is an obvious reason (e.g., gastrointestinal obstruction) for persistent vomiting or gastroesophageal reflux. Contrast Radiography $$ Contrast films may be used to confirm (or reveal) the stricture site and to determine if multiple strictures are present (visualization with an endoscope is limited to the first stricture site in most animals). However, the value of contrast films is a contentious issue, as many clinicians consider endoscopic visualization after dilation to be the best way to determine the presence of additional strictures. Caution is advised: Liquid barium products can pass through larger strictures undetected, and food or paste barium products may pose additional problems if they are regurgitated and aspirated. This complication should be discussed with owners before barium is used. Other Imaging Modalities Fluoroscopy of the esophagus, especially with the presence of contrast material, is very useful in assessing segmental motility defects, identifying a hiatal hernia, and revealing a defect in lower esophageal sphincter competence leading to gastroesophageal reflux. However, the latter two conditions can generally be seen with an endoscope. $$ Ultrasonography is not typically useful in assessment of the thoracic cavity; obvious exceptions include echocardiography (to look for evidence of persistent right aortic arch or other congenital defects causing esophageal dilation) or sonographic evaluation of thoracic masses. Like abdominal radiography, ultrasonography of the abdominal cavity is used to determine the presence of specific causes of persistent vomiting that could lead to esophagitis or stricture. $ $$ Endoscopy $$$ The endoscope is the definitive and preferred diagnostic tool for assessment of esophageal disease. Esophagoscopy allows definitive identification of esophagitis, esophageal anomalies (e.g., neoplasia, masses, foreign bodies), and strictures. Endoscopic visualization and retrieval (either using a rigid colonoscope or flexible gastroscope) is the STANDARDS of CARE: EMERGENCY AND CRITICAL CARE MEDICINE 3

4 preferred method of removing the majority of esophageal foreign bodies. Endoscopy also facilitates balloon dilation procedures because it allows careful placement of the balloon, observation during the ballooning procedure, and postballooning assessment of esophageal lumen size. Summary of Diagnostic Criteria Endoscopy is the definitive diagnostic test because it both allows assessment of mucosal lesions and potential causation (e.g., esophagitis, foreign bodies, neoplasia) and provides a means of treatment. Thoracic radiographs are extremely important and useful in the overall assessment of patients. History and physical examination findings are essential for providing clues to the presence of a foreign body or stricture (history is diagnostic in dogs that were chewing on a bone or grabbed a fishhook before developing signs). Laboratory workup is important not so much because of its diagnostic importance but because most of these patients require anesthesia for the endoscopic procedure needed to make the diagnosis and start therapy. Diagnostic Differentials For regurgitation (the most common sign of a foreign body or stricture): Esophagitis, including that caused by reflux during recent anesthesia. Esophageal foreign bodies. Esophageal stricture. Masses (granulomas, parasites, neoplasia). Esophageal motility disorders (megaesophagus, which can be congenital or secondary to such diseases as myasthenia, Addison s, or hypothyroidism). External obstructive disorders (persistent right aortic arch, thoracic masses). Gastroesophageal reflux diseases (persistent vomiting due to a variety of causes, hiatal hernia, abnormal lower esophageal sphincter function). For coughing or respiratory distress: Aspiration pneumonia. Bacterial or fungal pneumonia. Bronchial disease (feline asthma, canine reactive airways). Heart failure (valvular disease, cardiomyopathy). Heartworm disease. Tracheal disease (collapse, masses, parasites). Laryngeal disease (obstruction, paralysis, masses). TREATMENT RECOMMENDATIONS Initial Treatment The main goals of treatment are to (1) eliminate the underlying cause of the injury if possible (e.g., remove the foreign body, correct esophagitis or vomiting), and (2) return function (e.g., through dilation of the stricture and treatment of esophageal injury) to the greatest extent possible so that the pet is able to maintain its body weight and hydration via oral feeding with a minimum of regurgitation. Even if the initial dilation is successful in achieving a functional opening of the esophagus, future procedures may be required (months or years later) to facilitate passage of food through the opening. Foreign Bodies $$ $$$ For esophageal foreign bodies, the approach to removal depends to some degree on the type of foreign body, its location, and the duration that it has been lodged there. For most retrieval procedures, the flexible endoscope is used to visualize the problem and determine the best means of removal. Some foreign objects can be retrieved by using grasping forceps passed through the endoscope s working channel. However, for bones, fishhooks, and most large objects, a rigid colonoscope is used to visualize the area, dilate the esophagus, and protect it while the object is grasped and slowly retrieved. There are several advantages in using the rigid colonoscope to remove foreign bodies. The flexible endoscope is easily damaged by sharp edges, points of bones, or fishhook barbs, which is a costly mistake. The rigid scope dilates and protects the esophagus from the object as it is being slowly withdrawn and allows a more rigid grasping device to be introduced into the esophagus, which is very useful in unhooking anchored fishhooks or bones from the esophageal mucosa. Also, for distal esophageal foreign bodies that are not able to be safely withdrawn, the rigid scope can be used to help propel the object into the stomach, where it can be removed surgically. After removal of the foreign object from the esophagus, flexible endoscopy should be used to examine the esophageal mucosa and assess damage for prognostic purposes. It is also a wise to take new radiographs to ensure that pneumothorax a sign of perforation has not occurred. Strictures $$$ If the stricture opening is wide enough to accommodate liquid or soft food and regurgitation is infrequent, strict adherence to dietary modifications can be sufficient to manage the condition. This involves feeding small, frequent, gruel-based meals; preventing inges- 4 D E C E M B E R V O L U M E

5 tion of nonfood items, especially treats or chew toys in dogs; preventing hairball formation in cats; and administering only liquid medications. Specific therapy for esophageal strictures that are not amenable to conservative therapy is aimed at dilating the cicatrix slowly and progressively so that the fibrous band is broken down and heals with a more open lumen (with the intention of then implementing conservative medical management). This can be achieved by two basic methods: balloon dilation and bougienage. Both procedures require multiple episodes of general anesthesia, and either endoscopic or fluoroscopic guidance is needed during the procedures; thus, the treatment can become costly. Balloon Dilation Esophageal balloon dilation is performed by using a special balloon catheter (CRE Balloon Dilators, Boston Scientific, Boston, MA) that is passed through the endoscope or over a guide wire with endoscopic (preferred) or fluoroscopic guidance. The endoscope assists manipulation of the balloon catheter through the stricture site and provides good visualization of the procedure as the balloon is inflated. Thus, if excessive stretching or tearing occurrs, the procedure can be halted. The catheters come in a variety of sizes (6- to 20- mm balloons) and, as shown in published studies in humans, provide the best radial expansion of the stricture with the least amount of tearing (compared with bougies). The balloon is inflated using sterile water in a syringe attached to a pressure gauge to guide appropriate expansion of the balloon to the circumference desired. The number of dilation procedures needed depends on the size of the stricture, the degree of ongoing disease and inflammation, and response to the procedure. One to 10 dilation procedures every 2 to 4 days over a period of several days or weeks (using successively larger balloons) may be needed to successfully dilate the cicatrix to achieve a functional opening. Bougienage Bougienage is an alternative procedure used to dilate the stricture by passing metal bougies (rounded metal balls on a long pole) of increasing size through the stricture and thus stretching or tearing the fibrous tissue by force. This procedure was the most commonly used technique for many years until balloons became readily available and stronger balloon materials made them more effective in dilating the cicatrix. Although balloon procedures are currently more commonly used, bougienage may be needed to open some very dense strictures that are too strong for the balloon method to be used. Great caution must be used with bougienage because of the increased risk of tearing the esophagus (especially with inexperienced users). Like balloon dilation, bougienage is greatly facilitated by endoscopic or fluoroscopic guidance. Alternative/Optional Treatments/Therapy Interested readers are referred to recent surgical texts for descriptions of esophagotomy or partial esophagectomy procedures. Supportive Treatment $ For all patients with esophageal stricture, a liquid or gruel diet is usually necessary to allow easy passage through the narrowed area, regardless of whether balloon dilation is used. Life-long dietary management is often necessary because complete resolution of the stricture and normalization of esophageal function is unlikely. Some animals can eat canned foods, but it is rare for affected animals to be able to return to a completely normal diet and meal size. If gastroesophageal reflux is present, choosing a diet that is highly digestible and low in fiber and fat will improve gastric emptying. In addition, feeding small, frequent meals is important to increase gastric emptying and thus reduce reflux. If esophagitis is part of the stricture causation, longterm therapy to control gastric acid and prokinetics to improve gastric motility may be required to prevent recurrence. Therapy for esophagitis is generally supportive: The source of inflammation should be reduced if possible by administering antiemetics (metoclopramide, mg/kg SQ or IV q8h or by CRI, or dolasetron, mg/kg SQ or IV q24h) and prokinetics (metoclopramide [as above] or cisapride, 0.5 mg/kg PO q12h) as indicated. Gastric acid should be reduced by administering proton pump inhibitors (omeprazole, 1 mg/kg PO q24h) or histamine-2 receptor antagonists (famotidine, mg/kg PO q24h). In severe cases, judicious use of steroids (prednisone, 0.5 mg/kg PO q12h) may be indicated to reduce inflammation and scar formation. Patient Monitoring Regurgitation is the most common sign of recurrence of the stricture or obstruction of the stricture site with food, hair, or other objects. Anorexia and lethargy may also be seen in cats with stricture recurrence. Follow-up endoscopic evaluation is indicated if clinical signs recur. STANDARDS of CARE: EMERGENCY AND CRITICAL CARE MEDICINE 5

6 Home Management Liquid, liquid gruel, blenderized canned, or canned foods should be fed as directed (specific recommendation vary among patients; further guidance is beyond the scope of this article). Meals should be small and frequent (three to six meals daily may be required for some animals). The easiest foods to blenderize are the recovery or high-energy diets (Hill s Prescription Diet a/d or Iam s Maximum Calorie formula), but most canned diets can be blenderized and diluted sufficiently to pass through the narrower lumen. It is important to remember that when water is added to a diet, the calories are diluted and thus a greater volume is required to meet the patient s energy needs. Liquid diets, such as Clinicare (Abbott Laboratories), can be used as part of the regular diet or to dilute the canned food for mixing. It is vital to prevent animals with esophageal strictures from ingesting other foodstuffs, treats, chew toys, nonfood material, or large or hard items even animals with a functional opening have abnormal esophageal motility. Also, because the opening may not be large enough to allow passage of the swallowed material, a new obstruction could develop. In longhaired cats, stricture management should also include shaving the coat to prevent ingestion of large quantities of hair. Milestones/Recovery Time Frames There are no major recovery issues for the uneventful removal of esophageal foreign bodies; most dogs recover completely within days. The key milestones for recovery of a patient with a stricture is the reduction of regurgitation to a minimum and the ability of the patient to recover and maintain its body weight; this may occur after the first dilation procedure or may require multiple procedures over a period of several weeks. Complete resolution of regurgitation and the return to feeding a normal canned diet without the need for dietary management is a goal but is not often achieved. The risk of developing a clinically significant stricture more than 6 to 8 weeks after foreign body removal or surgery is minimal. Treatment Contraindications Prokinetic drug therapy should not be used in an attempt to promote passage of an esophageal foreign body or food through a stricture site. Foreign objects must not be blindly pushed into the stomach with a rigid tube or endoscope unless it is known that it is safe to do so. PROGNOSIS Favorable Criteria Foreign bodies that are removed immediately after ingestion, and endoscopic retrieval is uneventful. Minimal esophageal mucosal injury following removal of the foreign body. Esophageal stricture formation that results from an injury and not from neoplasia, fungal granuloma, or other disease requiring surgical intervention for correction. A patient that is able to eat liquid or liquid gruel food and does not regurgitate after balloon dilation to correct esophageal stricture. Maintenance of normal body weight and condition following balloon dilation to correct an esophageal stricture. Unfavorable Criteria An esophageal foreign body in the thoracic cavity that must be surgically removed Perforation of the esophagus while retrieving a foreign body, necessitating immediate surgical intervention. Patients with esophageal stricture that, despite repeated balloon dilation procedures, remains so small that oral feeding (even with liquid food) results in esophageal retention and regurgitation. Presence of aspiration pneumonia due to recurrent regurgitation. Esophageal neoplasia that results in obstruction or stricture formation. Esophageal diverticulum formation caused by the presence of a prolonged foreign body or stricture. RECOMMENDED READING Hedlund CS: Surgery of the digestive system, in Fossum TW (ed): Small Animal Surgery, ed 2. St. Louis, Mosby, 2002, pp Leib MS, Dinnel H, Ward DL, et al: Endoscopic balloon dilation of benign esophageal strictures in dogs and cats. J Vet Intern Med 15: , Sellon RK, Willard MD: Esophagitis and esophageal strictures. Vet Clin North Am Small Anim Pract 33: , Westfall DS, Twedt DC, Steyn PF, et al: Evaluation of esophageal transit of tablets and capsules in 30 cats. J Vet Intern Med 15: , Willard MD, Delles ED, Fossum TW: Iatrogenic tears associated with ballooning of esophageal strictures. JAAHA 30: , D E C E M B E R V O L U M E