P3.M246: Case Report: Identification of Multiple Small Intestinal Arteriovenous Malformations with Double Balloon Enteroscopy in a Pediatric Patient.

Introduction: Gastrointestinal arteriovenous malformation (AVM) is a rare condition associated with significant intestinal bleeding. Locating AVMs in the small intestine is challenging due to limitations of traditional diagnostic procedures like gastroscopy and colonoscopy.  Here, we present a case of multiple small intestinal AVMs successfully identified with double-balloon enteroscopy (DBE) and treated with Argon Plasma Coagulation (APC).

Case Description: A 16-year-old male with a medical history notable for eosinophilic esophagitis, GERD, and peptic ulcer disease presented with complaints of shortness of breath, palpitations, dizziness, and multiple episodes of blood in his stool over the past day. Notably, the patient had experienced a gastrointestinal (GI) bleed requiring hospitalization and blood transfusion one year prior. 
Blood work revealed mild anemia with hemoglobin of 10.1 g/dL, otherwise unremarkable. Fecal occult blood was positive and stool multiplex PCR assay was negative for enteric pathogens. Consequently, the patient was admitted for further investigation and close monitoring. 
Upper endoscopy revealed mild esophagitis, but otherwise appeared unremarkable. During colonoscopy, melanotic stool was observed coating the intestinal mucosa from the rectum to the ileum, however no definitive bleeding source was identified. Despite negative findings on a Meckel scan, suspicion for a bleeding Meckel's diverticulum remained high. Consequently, an exploratory laparoscopy was performed, yet no pathology was found. CT angiography also failed to pinpoint the source of bleeding. Attempts at video capsule endoscopy (VCE) was unsuccessful due to the patient's inability to swallow the capsule. 
On subsequent days his hemoglobin dropped to 6 g/dL requiring transfusion which urged rapid diagnostic evaluation. Despite not being typically performed in the pediatric population, a DBE was planned.  During the enteroscopy, multiple small AVMs were discovered in the jejunum and ileum. These AVMs were actively bleeding, to address this, an ablation procedure utilizing argon plasma coagulation (APC) was successfully carried out to cauterize and seal off the abnormal blood vessels.

Discussion: Small intestinal hemorrhage accounts for 16% of pediatric GI bleeding, mainly attributed to Meckel’s diverticulum, with AVMs rarely diagnosed in childhood. An AVM typically presents as a submucosal protrusion with redness, vascular proliferation, and ectasia, often accompanied by a pulsatile submucosal protrusion along with a small red patch on the top. VCE and DBE are valuable diagnostic tools for identifying small bowel AVMs with approximately 90% diagnostic yield. Besides diagnostic accuracy, DBE offers therapeutic interventions such as endoscopic hemostatic therapy, injection sclerotherapy, endoscopic clip application and argon plasma coagulation, as seen in our case.

Conclusion: Although AVMs in pediatric patients are rare, it should be considered in the differential diagnosis for those with obscure GI bleeding. A systematic step-by-step diagnostic evaluation is crucial for reaching a final diagnosis. Thus, we recommend early utilization of VCE and DBE to avoid more invasive procedures.