Esophageal Foreign Bodies

Lee Herold DVM, DACVECC, discusses the many items that can cause esophageal foreign bodies and how to treat them.

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Esophageal foreign bodies in dogs are an uncommon presentation in the veterinary ER - estimated to comprise ~ 0.09% of veterinary ER admissions. However, when they do occur, they are quite memorable cases because they can be associated with dramatic clinical signs of acute retching, regurgitation, dysphagia, and sometimes respiratory distress. More chronic clinical signs of discomfort and dysphagia may be present with a partial esophageal obstruction or a chronic esophageal foreign body. Esophageal foreign bodies occur primarily in dogs with rare presentations of cats with esophageal foreign body obstruction.  Though esophageal foreign body can occur in any breed or age canine, young to middle aged small breed and terrier dogs are predisposed. Though it has not been reported in the literature, it is intuitive that patients with previously diagnosed esophageal strictures or esophageal motility disorders may be predisposed to esophageal foreign bodies. The most common canine esophageal foreign bodies are bone material, rawhides, or various treats. When these three types of foreign bodies are grouped together they comprise anywhere from 79-86% of the esophageal foreign bodies.  Other objects including fishhooks, bottle caps, sticks, string, and carpet and fabric material have been reported.  The most common feline esophageal foreign bodies are hairballs. The veterinary literature regarding feline esophageal foreign bodies is limited to isolated case reports or brief mentions in endoscopy textbooks. Despite the paucity of information the clinical approach to diagnostics and the available treatment options for feline esophageal foreign bodies is similar to recommendations for canine foreign bodies.

History and clinical signs are excellent at increasing the clinician’s suspicion for esophageal foreign body. At times the ingestion of the occluding object is witnessed or there is strong association with development of clinical signs after owners have given a treat to the patient. Gagging, retching, vomiting, regurgitation, hypersalivation are common clinical signs. If there is concurrent aspiration pneumonia or more chronic foreign body then clinical signs of systemic illness may be present including fever, anorexia and lethargy.

Fortunately diagnosis is typically straight forward and plain thoracic radiographs are diagnostic for esophageal foreign body in 91% of cases. Figures 1, 2, 3 are examples of radiographic appearances for some esophageal foreign bodies.  Ensure that the radiographs include the cervical esophagus and if possible the stomach. In descending order the most common sites within the esophagus for foreign bodies to lodge in are the distal esophagus (between the heart base and diaphragm), at the level of the heart base, just caudal of the pharynx and at the thoracic inlet. In addition to visualization of the foreign body there are other things to pay attention to on thoracic radiographs that may indicate a possible esophageal foreign body. An example is esophageal gas distension which can occur either orad or aborad to the foreign body, gastric distension due to aerophagia, or aspiration pneumonia that may be present with regurgitation. Examine the radiographs for signs of possible esophageal perforation including pneumothorax, pneumomediastinum, or pleural effusion. Those esophageal foreign bodies that were not detected radiographically were objects that have a “soft tissue” opacity and were not surrounded by esophageal gas making them more difficult to detect. These materials include raw hides, wood material, and some cloth type foreign objects. Other imaging modalities including contrast esophagrams, and esophageal fluoroscopy can highlight esophageal foreign bodies but are rarely required to achieve a diagnosis of esophageal foreign body. Contrast esophagram and fluoroscopy can be helpful in the diagnosis of other esophageal disorders including esophageal diverticula, esophageal stricture formation or motility disorders. Administration of contrast should be carefully considered in patients in whom esophageal obstruction is suspected as the risk for regurgitation and aspiration of contrast media is high. Esophagoscopy can be used as diagnostic tool and as part of the treatment for esophageal foreign bodies. Results of lab tests including complete blood count, and serum biochemistry abnormalities have been reported in dogs with esophageal foreign but no results are specific for this condition. Bloodwork is most often performed as a pre-anesthetic screen prior to definitive treatment for esophageal foreign body. In patients in which a foreign body is more chronic and/or the clinical signs are less localizing bloodwork is recommended as part of the diagnostic workup for any ill patient.

Figure 1

Various radiographic appearances for esophageal foreign bodies.

Figure 2

Various radiographic appearances for esophageal foreign bodies.

Figure 3

Various radiographic appearances for esophageal foreign bodies.

The successful treatment of esophageal foreign bodies entails the retrieval or dislodgement of the foreign object from within the esophagus. Any of these interventions are performed under general anesthesia with intubation to protect the airway. There are many options to achieve the goals of dislodgement or retrieval including options that require no specialized equipment. The success of the various interventions of course relies on the type of foreign body, the location of the obstruction but also often the persistence and creativity of the clinician.

The first option for treating esophageal foreign body is blinded orad retrieval. This is most successful with foreign objects that are located within the cervical esophagus. Because most of these dogs are small breed dogs you can externally palpate the foreign body within the cervical esophagus. Occlude or have an assistant occlude the esophagus aborad to the foreign body to prevent you from pushing the foreign body down further when you are trying to grasp it. While you are directly palpating the foreign body, attempt to grasp it orally with long carmalts or rigid graspers for orad retrieval. Since this is a blinded grasp take care to try to avoid grasping the esophagus or other soft tissues as this can cause esophageal tearing or perforation.  When retracting you can typically get a “feel” for whether the object is moving or whether you have accidently grasped tissue. If you suspect you have grasped tissue then open the forceps and re-grasp the object. Another trick when attempting blinded orad retrieval of an esophageal foreign body is to advance a large foley urinary catheter distal to the foreign object. Again have an assistant occlude the esophagus aborad to the object. Feed a lubricated large foley catheter distal to the foreign object; palpate the cervical esophagus to guide your foley catheter advancement. When the catheter including the foley balloon is distal to the object then inflate the foley catheter balloon within the esophagus. Gently retract the foley with balloon inflated with a smooth and constant pressure. If the object is not strongly lodged within the cervical esophagus it will be able to be retracted in front of the inflated foley balloon. Often the object will not be able to be pulled through the pharyngeal region with this method; however, by the time the object is at the pharynx it can be directly visualized from the oral cavity for retrieval. This foley technique avoids the potential complication of grasping the esophagus with carmalts or other tools.

The next blinded technique for dislodgement of an esophageal foreign body is advancement of the object into the stomach. This is achieved by gentle passage of a lubricated orogastric tube to push the foreign object into the stomach. This technique can be successful for objects that do not have sharp edges and that are not strongly lodged within the esophagus. This option is better for acute foreign bodies because chronic foreign bodies have a greater likelihood to have caused esophageal erosion and be partially imbedded in esophageal mucosa making this blinded advancement a little riskier. Repeat lateral radiograph will tell you if you have successfully moved the object to the stomach. After the object is within the stomach it can either be left there for digestion (raw hides, treats, or other easily digestible foreign bodies) or for non-digestible objects removed via surgical gastrotomy.

Non-blinded or guided technique for management of esophageal foreign bodies is achieved with esophagoscopy. The disadvantage of this technique is the requirement for rigid or more commonly flexible endoscopy equipment and additional operator training. Obviously an advantage of esophagoscopy is that it allows direct visualization of the foreign body and evaluation of the esophageal mucosa during and after foreign body movement. Figures 4 and 5 represent normal esophageal appearance in a dog and a cat. Figure 6 is the appearance of a “raw hide” type foreign body within the esophagus of a dog. Under guided visualization foreign bodies can be grasped with flexible through the scope graspers or loops for orad retrieval. The foreign object can also be pushed into the stomach under direct visualization with the endoscope or stomach tube.  Reported successful orad retrieval rates with endoscopy are variable from 25-53%. These variable rates of retrieval are likely related to endoscopist’s experience, the type of foreign object and the chronicity of obstruction. The endoscope was used to successfully dislodge the foreign object into the stomach in as much as 70% of cases. As with the blinded techniques, after the object is in the stomach it can be left there to digest or retrieved via surgical gastrotomy.

Figure 4

Normal esophageal appearance of a dog

FIgure 5

Normal esophageal appearance of a cat

Figure 6

Endoscopic appearance of a raw hide type foreign body within the esophagus of a dog

If dislodgement to the stomach or orad retrieval is not successful, then thoracotomy for esophagotomy is indicated to relieve esophageal foreign body obstruction. Esophageal surgery is often the last resort to treat esophageal foreign bodies due to concerns over higher rates of complications including dehiscence, and infection associated with esophagotomy compared to other gastrointestinal surgery, and the requirement for thoracotomy.  A thoracotomy may be indicated when there is clear evidence of esophageal perforation that requires closure, thoracic lavage and culture sampling. Thoracotomy is associated with longer hospital stays than endoscopy or simple gastrotomy.

Esophageal foreign bodies can result in varying levels of esophagitis and perforation. The Savary-Miller (Table 1) esophagitis grade is used in humans to grade esophagitis and has been used in two retrospective studies of esophageal foreign bodies in dogs to stratify the degree of esophageal injury. Stratification in this grading system is based on endoscopically evaluated esophageal lesions. Higher grade of esophagitis has been associated with longer recovery time and longer length of hospitalization in dogs. Patients with higher esophagitis grades had significantly more early complications (aspiration pneumonia, esophageal perforation, pneumothorax, tracheal compression, esophageal necrosis, death) compared to those with mild or no esophagitis. The rates of longer term complications including strictures could not be compared due to low incidence of strictures in patients with mild esophagitis. Overall rates of stricture formation are not known and this is likely because follow-up endoscopy is often not performed especially if patients fully recover clinically. Figure 7 demonstrates a patient with circumferential erosions, Savary Miller Grade III esophagitis.

Figure 7

Grade III esophagitis

Post esophageal foreign body care is not standardized but usually involves some combination of H2 receptor antagonists, proton pump inhibitors, and sucralfate with the purported benefits of treating or reducing esophagitis. Analgesic management is appropriate if esophagitis is present or if surgery was required for foreign object retrieval. If deep circumferential erosions are present some clinicians will advocate placement of gastrostomy tube to allow for esophageal by-pass during healing and early return to nutrition. There is no literature that supports or refutes the use of gastrostomy tubes in these patients and the decision to place these tubes is due to clinician judgment.  Deep circumferential erosions are thought to be more likely to form strictures. Therefore, if there are no other contraindications, short course systemic steroid therapy with prednisone may be chosen as an anti-fibrotic in the hopes of minimizing stricture formation. Steroid therapy should be used very cautiously in patients with signs of aspiration pneumonia or who are at high risk of aspiration that may not have manifested radiographically yet.

The prognosis with esophageal foreign bodies is good with successful management in >93-95% of patients even in those patients requiring thoracotomy. Most of the complications associated with esophageal foreign body are mild including treatable and transient mild esophagitis and dysphagia. However more severe complications including esophageal perforation, life threatening hemorrhage, and death have been reported.

Table 1: Savary-Miller Esophagitis Grade

Esophagitis Grade

Endoscopic Characteristics

Grade I

Single non-confluent erosions

Grade II

Confluent erosions but non-circumferential

Grade III

Circumferential erosions

Grade IV

Esophageal ulcerations, stenosis, or perforation

 

 

Selected References/Suggested Reading:

1.         Cohn L a, Stoll MR, Branson KR, Roudabush AD, Kerl ME, Langdon PF, et al. Fatal hemothorax following management of an esophageal foreign body. J Am Anim Hosp Assoc. 2003;39:251–6.

2.         Gualtieri M. ESOPHAGOSCOPY. Vet Clinics of North America: Small Animal Practice 2001;31(4):605–30.

3.         McBrearty AR, Ramsey IK, Courcier E a, Mellor DJ, Bell R. Clinical factors associated with death before discharge and overall survival time in dogs with generalized megaesophagus. J Am Vet Med Assoc. 2011;238(12):1622–8.

4.         Rousseau A, Prittie J, Broussard JD, Fox PR, Hoskinson J. Incidence and characterization of esophagitis following esophageal foreign body removal in dogs: 60 cases (1999-2003). J Vet Emerg Crit Care. 2007;17(2):159–63.

5.         Sale CSH, Williams JM. Results of transthoracic esophagotomy retrieval of esophageal foreign body obstructions in dogs: 14 cases (2000-2004). J Am Anim Hosp Assoc. 2006;42:450–6.

6.         Thompson HC, Cortes Y, Gannon K, Bailey D, Freer S. Esophageal foreign bodies in dogs: 34 cases (2004-2009). J Vet Emerg Crit Care. 2012;22(2):253–61.

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