Surgery pearls: Removing linear foreign bodies in dogs

As anyone who routinely performs gastrointestinal (GI) surgery will attest, all foreign bodies are not created equal. While gastric, and some small intestinal, foreign bodies can be treated successfully in primary care practice, linear foreign bodies can create a much more challenging scenario for the surgeon, and can be potentially life-threatening for our patients. During a recent Fetch® dvm360 conference, Bronwyn Fullagar, BVSc, MS, DACVS, a specialist small animal surgeon based in Canmore, Alberta, offered some great advice for detecting and treating linear foreign bodies in dogs.

“It’s important to understand some key techniques for treating them that will greatly improve your patient outcomes,” Fullagar said. “In addition to preoperative patient stabilization, gentle tissue handling, and meticulous suture placement, it is really helpful to have had lots of prior experience performing GI surgery on nonlinear foreign body cases before taking on your first linear case. If in doubt, it’s never wrong to refer these more challenging cases to a specialist.”

Look for gas patterns on radiographs

Fullagar began by sharing a few diagnostic tips she learned from a veterinary radiologist. “One feature of linear foreign bodies that can make them trickier than other foreign bodies to diagnose on x-rays is that about 50% don’t cause any small intestinal dilation that’s visible on radiographs,” she explained. But that doesn’t mean you’ll always need to resort to ultrasonography straight away. You just have to know what to look for, and in the case of linear foreign bodies, it’s characteristic comma- or paisley-shaped gas patterns, often combined with evidence of small intestinal plication and/or loss of serosal detail (Figure 1). If you’re still unsure, abdominal ultrasound is usually the next logical diagnostic step.

Figure 1. Characteristic left lateral abdominal radiograph of a dog with a linear gastrointestinal foreign body. Note the foreign material present in the pylorus, plicated small intestine, and comma-shaped gas patterns.

Take left lateral radiographs

Another radiography tip Fullagar passed along was to always obtain 3 views of the abdomen, including a left lateral radiograph, on any dog you think might have a GI foreign body. “The left lateral shows what’s left in the stomach,” she explained. “When a dog is in left lateral recumbency, the pylorus, on the dog’s right side, will be uppermost. The gas will rise into it and nicely highlight whatever is in the pylorus.” In dogs, Fullagar noted, most linear foreign bodies will be anchored in the pylorus.

Be prepared for resection and anastomosis

If you suspect a linear foreign body in your patient based on radiographs or ultrasound, Fullagar stressed that you need to be prepared to do an intestinal resection and anastomosis. “About 40% of dogs [with a linear GI foreign body] will have septic peri- tonitis at the time of surgery,” she said. Intestinal resection-anastomosis usually requires a surgical assistant and is more technically difficult than an enterotomy. “So, if you’re not experienced in assessing the viability of small intestine, or if you haven’t done a small intestinal resection-anas- tomosis before, make sure you have either a mentor to help or consider referring the case,” she said. “You don’t want to get halfway through surgery and think, ‘I need to resect some of this intestine, but I’ve never done it before.’”

Make an appropriate surgical approach

Visualization is key. Start with a celiotomy incision that’s large enough for you to perform a complete exploratory laparotomy. “This isn’t an elective procedure that you’re doing,” Fullagar said. “This is an emergency surgery and good visualization is very important. So, the incision should usually start at the xiphoid and go to the fourth mammary gland of a female dog, or to the tip of the prepuce of a male dog.” Fullagar also stressed the impor- tance of keeping the abdominal tissues moist throughout the procedure, to avoid postoperative adhesions. “Using moistened lap sponges to isolate the part of the abdomen that you’re doing surgery on will prevent other struc- tures from drying and will also avoid contamination of the abdomen from GI contents,” she said.

Release the anchor point first.

In dogs, this usually means starting with a gastrotomy. Although most abdominal surgery begins with exploration of the abdomen, in cases where there is obvious small intestinal plication from a linear foreign body, Fullagar recommends very gentle handling of the intestine initially, and waiting until the foreign body has been removed before completing full abdominal exploration. “What you don’t want to do is manipulate this very plicated intestine excessively, because you risk causing more damage to the mesenteric border, which may be compromised by the foreign body,” she explained. Instead, Fullagar gently protects the plicated portion with moistened laparotomy sponges and follows the foreign body to its proximal anchor point, which in dogs is usually the pylorus. “Usually you’ll palpate something in a dog’s stomach,” she continued. That’s because, according to Fullagar, dogs tend to eat more “robust” items like toys, pieces of carpet, socks, and dish- rags. “Cats are a little different, as they are more prone to eating tiny piece of thread, and the surgical technique is slightly different,” she added.

After confirming the material is anchored in the pylorus, Fullagar performs a gastrotomy. “Don’t forget to use stay sutures to exteriorize the stomach, and isolate the stomach with moistened laparotomy sponges to prevent spillage of stomach contents,” she added. “The stomach of a patient with a linear foreign body is often full of fluid, so if this is the case, an orogastric tube can passed intraoperatively to drain some of this fluid prior to gastrotomy.”

The gastrotomy should be performed close to the pylorus, over the region where the foreign material is palpable (Figure 2). “Then what I’ll do at this stage is exteriorize the foreign body just far enough from the pylorus that I can get underneath the bulk of it and cut it with scissors,” she explained. Referring to a 10-year-old dachshund patient named Ollie who’d eaten a handkerchief, Fullagar noted, “It’s important not to pull too hard on the foreign body, as this can cause further damage to the small intestine. It’s very rare that a linear foreign body can be completely removed safely via a gastrotomy incision alone. You’re just going to cut underneath it and then release it,” she continued. “You should feel the remainder of the mate- rial move through the pylorus and into the duodenum.”

Figure 2. Intraoperative photograph of the dog in Figure 1. There is small intestinal plication. The foreign body is anchored in the stomach and extends to the mid-jejunum.

“Milk” the foreign body to relieve intestinal plication before enterotomy

Once the gastrotomy is complete, Fullagar gently “milks” the rest of the foreign body aborally (Figure 3). “You’re getting the part of the foreign body in the stomach to catch up with the part that’s farther down,” she said. “You’re also moving it into a healthier region of the intestine that’s safer for an enterotomy, because now it’s not attached anywhere. Usually the mate- rial ends up in the jejunum, which is the easiest part of the intestine to exteriorize for surgery. It’s more difficult to do an enterotomy in the duodenum, because this section is harder to exteriorize and closer to the pancreas.”

Figure 3. Following gastrotomy to relieve the anchor point of the foreign material, the material has been gently milked into the mid-jejunum to relieve the plication. Note that the small intestine is erythematous and edematous, and there is bruising along the mesenteric border.

And if you’ve started with the gastrotomy, Fullagar explained that in the vast majority of cases, you should be able to remove the entire foreign body through a single enterotomy. Minimizing the number of GI incisions will reduce the risk for postoperative dehiscence.

Evaluate the entire mesenteric border of the small intestine

According to Fullagar, even if you know your patient is going to need resection and anastomosis because you’ve already identified a small intestinal perforation, in most cases it is still helpful to remove the foreign body so you’re able to relieve the intestinal plication and fully assess the mesenteric border. “In linear foreign body cases, the mesenteric border is the place to really check very, very closely along the entire length for perforation—even if the overall color of the intestine is healthy,” she explained. “The mesenteric fat is often edematous, and this can make small perforations quite difficult to visualize. Surgical experience is really important when it comes to assessing intestinal viability.”

Don’t forget postoperative care

Fullagar ended by reminding the audience of the importance of postoperative care for patients who have undergone GI surgery for linear foreign bodies. “These patients may not have eaten for several days prior to surgery, and their intestinal tract is usually significantly more inflamed and edematous than that in patients that have had a solitary intestinal foreign body,” she explained. “The trauma and inflammation caused by the foreign body and plication, combined with general anesthesia and surgical manipulation, can lead to quite significant ileus, and it’s important to preemptively treat this to
give our patients the best chances of successful intestinal healing.”

In addition to rehydration with intravenous fluids and an opioid for pain relief, Fullagar recommends post- operative treatment with prokinetics and anti-emetics. Enteral feeding, starting within 12 hours of surgery, is also key to intestinal motility and healing, so a nasogastric feeding tube should be considered at the time of surgery for patients who have been anorexic. Referral to a facility with 24-hour care and monitoring can also be beneficial to maximize the chances of a successful outcome.

Remember that time when...

No veterinary surgery lecture on foreign bodies would be complete without a story that confirms the speaker’s credibility and leaves listeners in awe of what the canine body (and the veterinarian’s senses) can endure. Fullagar described a particularly nasty case in which a Labrador retriever got into a trash bag containing contents emptied from the home’s Diaper Genie, bathroom trash, and kitchen trash. “The dog ate the entire trash bag,” she lamented. “So, we induced emesis, and it vomited up 5 diapers. We took another radio- graph and could see that the stomach was still very full.” One surgery later, and the dog was successfully emptied of about 5 more diapers, whatever was in the bathroom trash, and some partially digested vegetables.

Hopefully, you won’t come close to topping this case in your own practice. But should the challenge arise, Fullagar’s advice should make the experience less painful.

Sarah Mouton Dowdy, a former associate content specialist for dvm360.com, is a freelance writer and editor in Kansas City, Missouri.