ENDOSCOPIC FOREIGN BODY REMOVAL
We all know our pets can chew on strange things at home or when out and about. Occasionally, they can swallow foreign objects, bones or even food which can become lodged in the oesophagus or stomach. When this occurs, it can be a medical emergency and require removal as soon as possible. Here at QVS, we often get referrals for animals needing medical intervention. Please keep reading to see how we investigate and treat these tricky cases.
Common Types of Foreign Bodies
You may be surprised to hear the kinds of things animals can swallow. Most commonly, we see referrals for swallowed bones, fabric (e.g. bedding, clothing), fish hooks, corn cobs or large seeds (e.g. peach seeds). Even tampons, nails or needles can be swallowed and wreak havoc. When the object in question is swallowed, it can get stuck before it gets to the stomach (in the oesophagus) or it can end up in the stomach. The animal will generally attempt to vomit up the object, and in most cases this is successful. However, if the object cannot be brought up and blocks the normal flow of ingesta, it can become a life-threatening problem.
Common Signs of Foreign Bodies
Occasionally, the only sign may be that the owner saw their pet swallow a foreign object. The most common example of this is when dogs or cats swallow fish hooks, seeds (e.g. peach seeds), string, a battery or part of a toy. If nothing has been witnessed, then signs generally occur due to obstruction of the digestive tract, which can occur within minutes to days. Signs include;
Vomiting, retching or regurgitating
Salivating
Inappetence (not wanting to eat)
Abdominal pain
Lethargy, dehydration and collapse in severe cases
Diagnostics - Radiology
Radiographs can be performed of the chest or abdomen. Chest radiographs generally are used to diagnose foreign bodies in the oesophagus. This can be used to confirm how far along the foreign body is within the oesophagus and can also give information of what type of foreign body it is (metal, bone, fabric/soft tissue) and may indicate how difficult it could be to remove. Radiographss can also give information on some possible complications, such as pneumonia (from aspiration of vomit), or free gas or fluid where it shouldn’t be (such as pleural space between the lungs and chest wall) which can indicate a rupture of the oesophagus.
Radiographs can also be performed on the abdomen, especially if the foreign object metallic or bone. They can also show you if the foreign body is causing a complete obstruction of the gastrointestinal tract. More commonly, ultrasound is employed (see below).
Unfortunately, some objects cannot be seen on Radiographs (such as some fabric foreign bodies) and so endoscopy may be required to both diagnose and resolve the problem.
Diagnostics - Ultrasound
If a foreign body further along past the oesophagus is suspected, abdominal ultrasound is generally employed to identify the presence of a foreign body and its location. It has the added advantage of being able to assess the other abdominal organs (liver, spleen, kidneys, bladder, adrenal glands), and to assess for possible gastrointestinal perforation (e.g. presence of free fluid or gas in the abdominal cavity).
One limit of abdominal ultrasound is if the animal has food in their stomach, it can be difficult to distinguish between foreign material or normal ingesta. Repeating the ultrasound hours later may be useful in these situations.
When Is Endoscopy Indicated
Endoscopy is employed in the following situations:
A foreign body is identified in the oesophagus.
A foreign body is in the stomach and is causing clinical signs (vomiting, abdominal pain, inappetence).
A foreign body is in the stomach and is at risk of causing a perforation (E.g. sharp objects such as needles)
A foreign body is in the stomach and is at risk of causing harm or death to the patient (e.g. batteries)
When Endoscopy May Not Be Indicated
If the foreign body in the stomach appears too large (E.g. large rock or hair ball), then surgery is often recommended.
If the foreign body has moved past the stomach into the intestinal tract, then surgery is required if it is causing an obstruction.
If the foreign body can be removed by inducing vomiting (e.g. small and not too sharp).
If the foreign body is not causing clinical signs and is considered likely to pass through without consequence, a ‘wait and see’ approach is occasionally employed.
Foreign Body Removal
The procedure has to be performed under a general anaesthetic. Often pre-anaesthetic bloodwork is performed to ensure electrolytes, kidney values and other parameters are normal. The patient may require some fluid rehydration prior to anaesthesia, especially if protracted vomiting has occurred.
Endoscopy involves using a long, flexible scope, with a video camera at the end so that the image can be seen on a T.V. screen adjacent to the patient. The veterinarian is able to pass the scope down the oesophagus, into the stomach and even the first part of the intestine. Once the foreign body is identified, graspers or wire loops are fed through a channel in the scope and are used to grasp the foreign object which can then be carefully dislodged and removed via the mouth with the scope. For foreign bodies in the oesophagus, larger graspers are often employed and are inserted beside the scope.
Benefits of Endoscopy
Removing objects using a scope is often less invasive and results in a speedier recovery for patients than surgical removal. Removal can often be faster than surgery (although this can vary depending on the type of foreign body). Generally, the procedure is also a cheaper option than surgery.
Risks of Endoscopy
Normal risks of general anaesthesia.
Once removed, especially if lodged for a prolonged period of time, the underlying tissue can be damaged and result in inflammation and ulceration. If this occurs in the oesophagus, then a possible complication is scarring of the food tube, resulting in formation of a stricture (narrowing of the oesophagus) which may require further intervention.
There is also a risk of oesophageal or gastric perforation, especially if the object is sharp. In these cases, the patient may require emergency surgery.
Post Endoscopy Care
The majority of patients with endoscopically removed foreign bodies go home the same or following day. We may elect to send them home with some antacids or gastroprotectants, anti-nausea medication or pain relief. Generally, follow up appointments are not required.