Surgery STAT: Surgical management of gastrointestinal foreign bodies
How to diagnose and effectively treat GI obstructions.
Veterinarians often hear clients report that their dogs and cats vomit after indiscriminant eating. Indeed, pets with gastrointestinal foreign bodies frequently present with a history of nausea, vomiting, inappetence, discomfort and lethargy.
Dr. Janice Buback
Sometimes signs are subtle or even absent in the case of a known recent ingestion and early presentation. Vomiting is a common sign of other maladies as well, which is why getting a complete patient history is imperative.
Diagnose the problem
A gastrointestinal (GI) foreign body is generally diagnosed based on history and physical examination findings, clinical signs and a radiographic examination.
Radiography is the first-line diagnostic tool for identifying GI foreign bodies (Photo 1); however, a foreign body is not always readily apparent. Obstruction is suggested by small intestinal loops that are dilated to greater than the width of the second lumbar vertebral body or by the presence of two populations of small intestine (i.e., normal sized and enlarged, gas-distended loops).
Photo 1: An abdominal radiograph showing an obvious metal density foreign body and mixed populations of small intestine. (Photos courtesy of Dr. Buback)
A barium study can confirm suspicions (Photo 2 and Photo 3). However, if you plan to use endoscopy, do not use barium. Ultrasonography can sometimes identify a GI foreign body or intestinal changes suggestive of a foreign body. Note, however, that gas in the GI tract can impair the ability to evaluate the abdomen.
Photo 2: A ventrodorsal view of a barium study demonstrating an intestinal foreign body.
Laboratory studies may support a diagnosis of obstruction (e.g., hypochloremic hypokalemic metabolic alkalosis with high duodenal obstructions), and it's always prudent to evaluate electrolyte concentrations.
Photo 3: A lateral view of the patient in Photo 2.
Determine the next step
Often the most challenging part of these cases is knowing when to cut and when to wait. An exploratory examination is recommended in any of the following scenarios:
- The patient continues to vomit
- Abdominal palpation elicits pain
- The patient has an obstructive gas pattern or one that has not changed over time with appropriate supportive care
- A known foreign body that's unlikely to safely pass on its own is present.
Good antiemetics are available, some of which are so effective they can control nausea and vomiting in an obstructed pet, thereby delaying diagnosis. Remember to assess the whole patient and all the information.
Common procedures performed for GI foreign bodies include gastrotomy, enterotomy (Photos 4 to 6,) or intestinal resection and anastomosis. Before gastrotomy, pass a gastric tube to remove excess fluid and gas. Isolate the affected sites from the rest of the abdomen, change instruments and gloves after completion and before closure to minimize contamination and, if indicated, obtain full-thickness biopsy samples prior to closing the site.
Photo 4: An intraoperative photo of the patient in Photos 2 and 3. Note the obvious foreign body in the jejunum.
You may be able to offer prophylactic gastropexy in cases of an uncomplicated foreign body. Gastropexy should be done at a new site at the pyloric antrum, not at the original gastrotomy site. A linear foreign body may require gastrotomy and one or more enterotomies. As always, plan your surgery to retrieve as much material as possible through the fewest sites. Perform intestinal resection and anastomosis when the intestine is compromised, nonviable or perforated. If there are multiple perforations or segmental regions of compromise, plan your surgery to minimize the number of resections needed. Risk of dehiscence does not significantly increase with multiple intestinal procedures, but surgery time is prolonged.
Photo 5: An enterotomy has been done, and a portion of a rubber ball is being removed.
If you do enough surgery, you will, at some point, have what appears to be a negative exploratory. But note, there should never be a truly negative exploratory. In a case in which a foreign body is not identified, it's strongly recommended that you obtain biopsy samples of the stomach and small intestinal tract and evaluate the entire abdomen to rule out other causes of GI upset. Discuss this possibility with the owner before surgery.
Photo 6: The enterotomy has been completed, and the site is being leak-tested with sterile saline solution.
Postoperative care and complications
Standard postoperative care for GI foreign body patients is shown in Table 1.
Table 1: Postoperative recommendations
The most detrimental complication after gastrointestinal surgery is leakage or dehiscence of the surgical site leading to life-threatening peritonitis. Note that the chance of leakage from a site is greater in dogs requiring surgery for removal of a foreign body than those needing intestinal surgery for any other reason. Leakage typically results from either poor surgical technique or a patient's compromised ability to heal. Poor apposition of tissues, improper suturing or stapling techniques and failure to recognize ischemic, devitalized tissue are technical errors that lead to leakage. A patient's ability to heal can be compromised by hypoalbuminemia, malnutrition, concurrent disease, medications (e.g., glucocorticoids, nonsteroidal anti-inflammatory drugs) or by some therapies (e.g., chemotherapy, radiation therapy).
Other potential complications include nausea, vomiting, ileus, anorexia and incisional problems. Most complications can be addressed medically and will resolve with appropriate supportive therapy. However, if peritonitis occurs, additional surgical intervention is warranted.
EDITOR'S NOTE: SurgerySTAT is a collaborative column between the American College of Veterinary Surgeons (ACVS) and DVM Newsmagazine.
Dr. Janice Buback is a surgeon with Lakeshore Veterinary Specialists, Port Washington and Racine, Wis. She is a proud Cheesehead (Go Packers!) and enjoys camping and other outdoor activities with her family and black Labrador, Angus (who so far has not needed surgery for a foreign body).
Next month, Dr. Kathleen Ham will address the topic of primary hyperparathyroidism.