A 4-year- old, female spayed, mixed breed dog presented to the DoveLewis Emergency Animal Hospital for evaluation of acute vomiting. At the initial visit, she was treated symptomatically on an outpatient basis, but vomiting and retching continued throughout the night and she re-presented the following morning for a full diagnostic evaluation and treatment.
On physical examination, the patient was BAR but estimated 6% dehydrated. Vital signs, pulse oximetry and blood pressure were within normal limits. The abdomen was soft and non-painful to palpation. Electrolytes, PCV, total solids, glucose, lactate, BUN and creatinine were also normal. Abdominal radiographs were taken demonstrating a 6 cm soft tissue opacity in the stomach. The effect was present on the VD as well as a third left lateral image (figure 1a-c). Differential diagnosis included a soft tissue gastric mass, or intraluminal foreign body. Abdominal ultrasound, endoscopic examination of the stomach and/or surgery if indicated was offered to the client, and endoscopy elected as the next procedure.
The patient was anesthetized routinely for gastroscopy. The stomach contained a moderate amount of brown fluid, which was removed via suction. A large fleshy mass was seen in the pyloric antrum with a central lumen. The surrounding gastric mucosa appeared normal although the mass appeared congested. The endoscope could not be passed through the central lumen or around the perimeter of the mass. No other masses, ulcerations or foreign material was noted. Negative contrast radiographs of the stomach were performed using air insufflated during endoscopy, and a tentative diagnosis of gastric intussusception made. The patient was prepared and moved to surgery for exploratory celiotomy.
At surgery, a gastro-gastric intussusception was diagnosed involving invagination of the antrum into the body of the stomach. The pylorus or duodenum was not involved. The intussusception was gently, manually reduced, revealing marked edema in the wall of the antrum. Fluid could easily pass from the body of the stomach through the antrum and into the duodenum, indicating patency of the gastrointestinal junction. Shortly after reduction, the gastric edema was improved and gastric motility was noted. The rest of the exploratory was within normal limits. Prophylactic gastropexy of the antrum to the right body wall was performed in standard fashion to help prevent recurrence of intussusception and to prevent future GDV in this deep chested dog.
The patient tolerated anesthesia and surgery well and was discharged the following evening with instructions to feed a liquid diet for three days and soft diet for 10 days to allow for complete resolution of gastric edema. She was treated with tramadol for pain, omeprazole for gastritis, and fenbendazole for potential parasites, although fecal float was negative. The patient made an unremarkable recovery.
Intussusception involving the stomach is rare. Six cases of pylorogastric intussusception have been reported in the veterinary literature to date 1,5, with variable outcomes. In the previously reported cases, severe electrolyte derangements and involvement of the pylorus and duodenum in the lesion with subsequent tissue necrosis ultimately contributed to poor outcomes in half of the cases. In the patient described here, a true gastrogastric intussusception was present without involvement of the pylorus or duodenum, contributing to a better outcome for this patient. Also, duration of onset of clinical signs to diagnosis and definitive treatment was less than 12 hours, decreasing the chance of extensive tissue involvement, permanent tissue damage and severe electrolyte derangement.
While ultrasound has been used successfully to diagnose intussusception involving the stomach3, 4, direct visualization with the endoscope allowed diagnosis of the intussusception, plus evaluation of the gastric lumen in a minimally invasive manner, negating the need for a gastrotomy to evaluate the lumen of the stomach looking for inciting causes such as foreign bodies, ulcerations, or masses. Negative contrast radiography using air to highlight the abnormal tissue in the stomach was simple to perform and very useful in making the diagnosis both by simply making the left lateral radiograph and highlighting the antral area with gas in the patient’s stomach, or by insufflating air and taking the right lateral radiograph. These techniques could be beneficial in diagnosis of any lesion in the pyloric and antral area of the stomach.
Surgery is the definitive means for treatment of the condition, which in this case was successful in resolving the condition and preventing recurrence. In one of the previously reported cases2, duodenal pexy to the right body wall was performed to try to prevent reoccurrence of the intussusception and in another surviving patient,5 both the duodenum and antrum were pexied to the body wall. In our case, since the dog‘s duodenum was not involved in the intussusception, standard antral pexy was performed to prevent a reoccurrence as well as a preventative for gastric-dilatation-volvulus (GDV), as the patient was a deep chested dog. In the human medical literature, gastropexy was performed as a preventative for gastrogastric intussusception with an excellent outcome3. The recurrence rate of gastric intussusception is not known, but is reported as high as 18.3% in small intestinal intussusception6.
Post-operative treatment for our patient was aimed at correcting and maintaining fluid and electrolyte balance, pain control, treating segmental gastritis in the intussuscepted gastric body, and judicious re-feeding in light of potential motility derangements and marked edema in the gastric outflow tract. Causes for both intestinal and gastric intussusception are largely unknown, but contributing factors include motility derangement due to factors such as parasitism, foreign bodies and intraluminal polyps or masses. Although fecal float was negative, the patient was empirically treated with fenbendazole to ensure any missed parasitic elements that could have contributed to the development of the lesion were treated.
Gastrogastric intussusception should be considered in patients with signs of pyloric outflow obstruction and a soft tissue mass visible on radiographs. Negative contrast radiography, endoscopy or ultrasound can be useful to confirm the diagnosis, with surgery as the definitive treatment. In this case, swift surgical intervention resulted in an excellent outcome for our patient.